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  • 1.
    Subedi, Yuba Raj
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    The response of ecosystems to an increasingly variable climate2012Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    A wide range of ecological communities ranging from polar terrestrial to tropical marine environments are affectedby global climate change. Over the last century, atmospheric temperature has increased by an average of 0. 60 C andis expected to rise by 1.1- 6.40C over the next 100 years. This rising temperature has increased the intensity andfrequency of weather extremes due to which a large number of species are facing risk of extinction. Studies haveshown that species existing on lower latitude are more sensitive to temperature variability compared to speciesexisting on higher latitude but temperature is increasing rapidly in higher latitude compare to lower latitude. Thisuneven distribution of temperature sensitive species and warming rate has highlighted the need for combined studiesof temperature variability and sensitiveness of species to predict how the ecosystems will respond to increasinglyvariable climate. Using a generalized Rosenzweig-MacArthur model, I explored how temperature variability andsensitivity of species will affect the extinction risks of species and how the connectance and species-richness ofecological communities will govern this response. This study showed that the risk of extinction of species mostlydepends on their sensitivity to temperature deviation from the optimum value and level of temperature variability.Among these two, sensitivity of species to temperature deviation was most prominent factor affecting extinction risk.In this study, connectance did not show any effect on mean extinction risk and time taken by a certain proportion ofspecies to reach pre-defined extinction thresholds. But, species-richness showed some effect on mean extinction riskof species. It was found that risk of extinction of species in species-rich communities was higher compared tospecies-poor communities. Species-rich communities also took shorter time before they lost 1/6 of the species. Thepresent study also suggests a possible tipping point due to increasing temperature variability in near future. In furtherstudies, different sensitivity of species at different trophic levels and the possible evolution of sensitivity of speciesshould also be consider while predicting how ecological communities will respond to changing climate in the longrun.

  • 2.
    Hammarfrid, Peter
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Henningsson, Tom
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Multifaktormodeller på den svenska marknaden - En studie av OMX Stockholm mellan 1996 och 20142015Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background:CAPM isn’t in some cases sufficient for explaining expected stock return. Some of CAPM´smispricing errors are well documented and time persistent which has led rise to the usage of correctivefactors. One model that make use of two such corrective factors are the Fama and French three factormodel. It´s been comprehensively tested on the Swedish market where it has shown to achieve higherexplanatory power then the CAPM. In the year of 2012 and 2014 two new Asset Pricing Models wereintroduced, which on the US stock market better captured many of the best known anomalies.Aim:The aim of the study is to test if the Fama and French five factor model as well as the Q-factor model,could contribute to increased explanatory power beyond the three factor model. The study also analyzethe models cyclical sensitivity as well as the individual factor significance.MethodologyThe knowledge building process takes a deductive approach. Existing theories in the form of assetpricing models are tested based on empirical observations in the Swedish market. The research take aquantitative approach and make use of econometric tools in order to ensure statistic accuratesignificance.Result:This research shows no contribution of explanatory power for the Q-factor model, beyond thatachieved from the Fama and French three factor model. The five factor model achieve marginallyhigher explanatory power compared to the tree factor model. The most likely reason why FF5Machieve better results than the Q-factor model is believed to lie in the usage of the factor HML. Theresults also shows that all of the tested models are very instable when used in a short time perspective.Although there are some clear indication on increasing explanatory power in recession compared to inan ongoing bull market.

  • 3.
    Merkel, Axel
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Socioeconomic Impacts of Transitioning to Collaborative Port Operations - A case study of the Port of Gothenburg2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study is to derive a method for estimation of costs and benefits of implementing Port Collaborative Decision Making (Port CDM), and to apply this method to the Port of Gothenburg. By using the Port of Gothenburg as a case study, conclusions can be drawn regarding the economic viability of Port CDM in one of Scandinavia‟s largest ports. This study considers two major sources of benefits that are hypothesized to result from transitioning to collaborative port operations: improved possibilities for speed optimization prior to arrival in port due to increased predictability in estimated berthing times, and shortened service times due to increased possibility for planning and resource optimization by port service providers.The estimation of impacts is based on one month‟s traffic data in the Port of Gothenburg. Predictability of estimations is analyzed to determine the benefit potential of Port CDM. The estimated cost savings for cargo vessels can be divided into 5 categories: bunker, emission, time, manning and capital cost savings. The costs of implementing and maintaining Port CDM are estimated with values from relevant previous research.The results of this study indicate that the implementation of Port CDM in the Port of Gothenburg is a profitable investment, for the shipping industry and for society as a whole. The estimated annual net benefit is 27.3 million euros. A sensitivity analysis using alternative unit valuations for emissions, as well as low and high estimations of the effectiveness of Port CDM, indicates that the economic viability of the project is robust under all assumptions considered.

  • 4.
    Bandla, Atchaiah
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Highly Linear 2.45 GHz Low-Noise Amplifier Design2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    One critical component of the communication receiver of front-end system is the low-noise amplifier (LNA). For good sensitivity and dynamic range, the LNA should provide a low noise figure and maximum attainable power gain. Another concern is the linearity of the LNA. Strong signals produce intermodulation products in a frequency band close to the operating frequency that might affect the performance of the receiver. In many cases, the intermodulation products can be reduced by increasing the current through the active device. Hence, a trade-off between power consumption and linearity must be considered when designing the LNA. The thesis includes the bias network design, stability analysis, matching network design and layout design of the LNA RF module with layout simulation. The simulation has been performed using Advanced Design System (ADS) simulation software. After implementation of LNA on a PCB, the LNA is measured with the help of the power supply unit and vector network analyzer. The proposed design aim is to provide a low noise figure (NF) and high gain while maintaining the low power consumption.

  • 5.
    Hongxing, Li
    et al.
    Department of Clinical Dentistry – Prosthodontics, University of Bergen, Bergen, Norway.
    List, Thomas
    Orofacial pain and Jaw Function, Malmö University, Malmö, Sweden.
    Nilsson, Ing-Marie
    Specialist Center for Oral Rehabilitation, Norrköping, Sweden .
    Johansson, Anders
    Department of Clinical Dentistry – Prosthodontics, University of Bergen, Bergen, Norway.
    Nordrehaug Astrom, Anne
    Department of Clinical Dentistry – Community Dentistry, University of Bergen, Bergen, Norway.
    Validity and reliability of OIDP and OHIP-14: a survey of Chinese high school students2014In: BMC Oral Health, ISSN 1472-6831, Vol. 14, no 158, 1-10 p.Article in journal (Refereed)
    Abstract [en]

    Background: To determine the impact of oral diseases on everyday life, measures of oral quality of life are needed. In complementing traditional disease-based measures, they assess the need for oral care to evaluate oral health care programs and management of treatment. To assess the reliability and validity of the Oral Impact of Daily Performance (OIDP) and the short-form Oral Health Impact Profile (OHIP-14) among high school students in Xian, the capital of Shanxi province, China. Methods: Cross-sectional one-stage stratified random cluster sample using high schools as the primary sampling unit. Students completed self-administered questionnaires at school. The survey included the OHIP-14 and OIDP inventories, translated and culturally adapted for China, and global oral health and socio-behavioral measures. Results: A total of 5,608 students participated in the study, with a 93% response rate (mean age 17.2, SD 0.8, 52% females, 45.3% urban residents). The proportion experiencing at least one impact (at any frequency) during the previous six months was 62.9% for the OHIP-14 and 45.8% for the OIDP. Cronbachs alpha measured internal consistency at 0.85 for OHIP-14 and 0.75 for OIDP while Cohens kappa varied between 0.27 and 0.58 for OHIP-14 items and between 0.23 and 0.65 for OIDP items. Kappa scores for the OHIP-14 and OIDP additive scores were 0.52 and 0.66, respectively. Both measures varied systematically and in the expected direction, with global oral health measures showing criterion validity. The correlation between OIDP and OHIP-14 was r(s) + 0.65. That both measures varied systematically with socio-behavioral factors indicates construct validity. Conclusion: Both the OIDP and OHIP-14 inventories had reasonable reliability and construct validity in relation to subjective global oral health indicators among adolescents attending high schools in China and thus appear to be useful oral health -related quality of life measures in this context. Overall, the OHIP-14 and OIDP performed equally well, although OHIP-14 had superior content validity due to its sensitivity towards less severe impacts.

  • 6.
    Hassan, Mao
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Pastoralist Way of Life Under Threat:: Assessing the vulnerability risks faced by pastoralist communities as well as their potential to adapt to climate change in the Horn of Africa2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of the thesis was to examine the main causes of pastoral  vulnerability to climate change as well as assess their adaptive capacity to withstand future climate disturbances in the Horn of Africa. By studying two of the most iconic pastoralists’ communities in Africa – the Somali and the Massai’s in Kenya, the study intended to use the communities as representative to the overall pastoralist’s situation in the Horn of Africa. The study used the 2007 IPCC Vulnerability Assessment framework that entails exposure, sensitivity and adaptive capacity to climate change as a guiding instrument to comprehend the complexities of the pastoral livelihood. The participants of the study included pastoralists, officials from the government, NGO’s and research Institutions. Major findings of this study were, in addition to climate manifesting in destructive forms, pastoralism faces political marginalization, shrinking pastureland, sprawling urbanization, exponential growth of population and conflicts. Despite the challenges, the study also finds strong adaptive capacity by the pastoralists. Adaptation strategies include traditional methods of rangeland management and migration. The study also shows new modern methods adaptation to climate mainly instigated by the pastoralists with assistance from external actors, these methods include; Ecological Based Adaptation and technology driven approaches as well as a mixture of agriculture and pastoralism – agro-pastoralism. It was also found that the two communities studied face different climate challenges and adaptation approaches.

  • 7.
    Mellema, J.J.
    et al.
    Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Harvard Medical SchoolBoston, MA, United States.
    Doornberg, J.N.
    University of of Amsterdam Orthopaedic Residency Program (PGY 4), Academic Medical CenterAmsterdam, Netherlands.
    Guitton, T.G.
    University of of Amsterdam Orthopaedic Residency Program (PGY 4), Academic Medical CenterAmsterdam, Netherlands.
    Ring, D.
    Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Harvard Medical SchoolBoston, MA, United States.
    Biomechanical studies: Science (f)or common sense?2014In: Injury, ISSN 0020-1383, E-ISSN 1879-0267, Vol. 45, no 12, 2035-2039 p.Article in journal (Refereed)
    Abstract [en]

    Introduction: It is our impression that many biomechanical studies invest substantial resources studying the obvious: that more and larger metal is stronger. The purpose of this study is to evaluate if a subset of biomechanical studies comparing fixation constructs just document common sense. Methods: Using a web-based survey, 274 orthopaedic surgeons and 81 medical students predicted the results of 11 biomechanical studies comparing fracture fixation constructs (selected based on the authors sense that the answer was obvious prior to performing the study). Sensitivity, specificity, and accuracy were calculated according to standard formulas. The agreement among the observers was calculated by using a multirater kappa, described by Siegel and Castellan. Results: The accuracy of predicting outcomes was 80% or greater for 10 of 11 studies. Accuracy was not influenced by level of experience (i.e., time in practice and medical students vs. surgeons). There were substantial differences in accuracy between observers from different regions. The overall categorical rating of inter-observer reliability according to Landis and Koch was moderate (k = 0.55; standard error (SE) = 0.01). Conclusion: The results of a subset of biomechanical studies comparing fracture fixation constructs can be predicted prior to doing the study. As these studies are time and resource intensive, one criterion for proceeding with a biomechanical study should be that the answer is not simply a matter of common sense. © 2014 Elsevier Ltd. All rights reserved.

  • 8.
    Magiera, Sylwia
    et al.
    Silesian Technical University, Poland.
    Baranowski, Jacek
    Determination of carnitine and acylcarnitines in human urine by means of microextraction in packed sorbent and hydrophilic interaction chromatography-ultra-high-performance liquid chromatography-tandem mass spectrometry2015In: Journal of Pharmaceutical and Biomedical Analysis, ISSN 0731-7085, E-ISSN 1873-264X, Vol. 109, 171-176 p.Article in journal (Refereed)
    Abstract [en]

    A method using semi-automatic microextraction by packed sorbent (eVol (R)-MEPS) and hydrophilic interaction chromatography-ultra-high-performance liquid chromatography-tandem mass spectrometry (HILIC-UHPLC-MS/MS) was described for the simultaneous determination of carnitine and acylcarnitines in human urine. The optimal conditions of MEPS extraction were obtained using C2 of M1 (C8 + SCX) phase as a sorbent Chromatographic separation of the analytes was achieved within 2.5 min on Acquity UPLC BEH HILIC column using a gradient elution program with water containing 5 mM ammonium acetate and acetonitrile as the mobile phase. The detection was performed on a triple-quadrupole tandem mass spectrometer in a positive ion mode via electrospray ionization (ESI). The linearity of the calibration curves for all compounds was found over a range from 0.1 ng/mL to 500 ng/mL. The method afforded satisfactory results in terms of sensitivity, specificity, precision, accuracy, recovery as well as stability of the analyte under various conditions. The method was used successfully for determination of carnitine and acylcarnitines in human urine.

  • 9.
    Christiansson, Åsa
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, Faculty of Arts and Sciences.
    Evaluation of the attachment scale in the Trauma Symptom Inventory-2: Parental experiences of traumatic events and close relationships2013Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this study was to evaluate the psychometric properties of the attachment scale added in the newly developed self-rating questionnaire Trauma Symptom Inventory-2 (TSI-2). Participants were recruited from the Swedish parent-infant unit Hagadal (N=58). Reliability analyses concluded Cronbach´s α .92 for attachment total scale, .88 for avoidance subscale, and .91 for rejection sensitivity subscale. Convergent validity analyses concluded moderate to strong correlations between TSI-2 attachment scale and subscales, and Experiences in Close Relationships (ECR) total scale and subscales (r= .34 - .68, p ≤ .01). Criterion validity analyses concluded that adverse childhood circumstances measured by Linköping Youth Life Experiences Scale (LYLES) signficantly estimated 17 % of variance in TSI-2 attachment scale scores. Preliminary support for reliability and validity of the TSI-2 attachment scale was obtained. No previous trauma symptom rating instrument has included information about adult attachment styles. The present findings point to the benefits of such inclusion.

  • 10.
    Lagervall, Malin
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Samuelsson, Sandra
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Microscopic Simulation of Pedestrian Traffic in a Station Environment: A Study of Actual and Desired Walking Speeds2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In order to attract pedestrians to travel with public transport instead of private cars, the layout of interchange stations is important and should be designed in an effective way. Microscopic simulation of pedestrians can be used to evaluate different layout scenarios or a future increase in flow. The simulation software Viswalk was investigated, where the movements of pedestrians are based on a social force model,. The purpose of this thesis was to investigate simulated walking speeds for different flow levels and to investigate the effects of dividing pedestrians into types with different desired speeds. The aim was to find a desired speed distribution that can be used for different flow levels. Field studies have been performed to collect pedestrian traffic data with a video camera at Stockholm Central Station. Two disjoint flow levels were identified and used to investigate if the same desired speed distribution could be used for different flow levels. The average observed walking speed was 1.33 metres per second at the low flow level and 1.25 metres per second at the high flow level. The error was 4.5 percent between the average observed walking speed and the average simulated walking speed when the optimal desired speed distribution at the low flow level was used at the high flow level. Effects of using different desired speed distributions for different pedestrian types have also been investigated. The error between the average of the observed and the simulated walking speeds varies between 2.3 and 4.1 percent when dividing pedestrians into different types when the optimal desired speed distributions at the low flow level are used at the high flow level. A sensitivity analysis of some parameters of the social force model in Viswalk has also been performed. Several adjustments of the parameters show that some parameters had great impact of the simulated walking speeds. The final conclusion is that the parameter configuration and how the pedestrians are divided into different types affect the average simulated walking speed.

  • 11.
    Prabahar, Jasila
    Linköping University, Department of Biomedical Engineering. Linköping University, The Institute of Technology.
    Localization of Stroke Using Microwave Technology and Inner product Subspace Classifier2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Stroke or “brain attack” occurs when a blood clot carried by the blood vessels from other part of the body blocks the cerebral artery in the brain or when a blood vessel breaks and interrupts the blood flow to parts of the brain. Depending on which part of the brain is being damaged functional abilities controlled by that region of the brain is lost. By interpreting the patient’s symptoms it is possible to make a coarse estimate of the location of the stroke, e.g. if it is on the left or right hemisphere of the brain. The aim of this study was to evaluate if microwave technology can be used to estimate the location of haemorrhagic stroke.

    In the first part of the thesis, CT images of the patients for whom the microwave measurement are taken is analysed and are used as a reference to know the location of bleeding in the brain. The X, Y and Z coordinates are calculated from the target slice (where the bleeding is more prominent). Based on the bleeding coordinated the datasets are divided into classes. Under supervised learning method the ISC algorithm is trained to classify stroke in the left and right hemispheres; stroke in the anterior and posterior part of the brain and the stroke in the inferior and superior region of the brain. The second part of the thesis is to analyse the classification result in order to identify the patients that were being misclassified.

    The classification results to classify the location of bleeding were promising with a high sensitivity and specificity that are indicated by the area under the ROC curve (AUC). AUC of 0.86 was obtained for bleedings in the left and right brain and an AUC of 0.94 was obtained for bleeding in the inferior and superior brain. The main constraint was the small size of the dataset and few availability of dataset with bleeding in the front brain that leads to imbalance between classes. After analysis it was found that bleedings that were close to the skull and few small bleedings that are deep inside the brain are being misclassified. Many factors can be responsible for misclassification like the antenna position, head size, amount of hair etc.

    The overall results indicate that SDD using ISC algorithm has high potential to distinguish bleedings in different locations. It is expected that the results will be more stable with increased patient dataset for training.

  • 12.
    Hirani, Shyam
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Wallström, Jonas
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    The Black-Litterman Asset Allocation Model: An Empirical Comparison to the Classical Mean-Variance Framework2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Within the scope of this thesis, the Black-Litterman Asset Allocation Model (as presented in He & Litterman, 1999) is compared to the classical mean-variance framework by simulating past performance of portfolios constructed by both models using identical input data. A quantitative investment strategy which favours stocks with high dividend yield rates is used to generate private views about the expected excess returns for a fraction of the stocks included in the sample. By comparing the ex-post risk-return characteristics of the portfolios and performing ample sensitivity analysis with respect to the numerical values assigned to the input variables, we evaluate the two models’ suitability for different categories of portfolio managers. As a neutral benchmark towards which both portfolios can be measured, a third market-capitalization-weighted portfolio is constructed from the same investment universe. The empirical data used for the purpose of our simulations consists of total return indices for 23 of the 30 stocks included in the OMXS30 index as of the 21st of February 2014 and stretches between January of 2003 and December of 2013.

     

    The results of our simulations show that the Black-Litterman portfolio has delivered risk-adjusted return which is superior not only to that of its market-capitalization-weighted counterpart but also to that of the classical mean-variance portfolio. This result holds true for four out of five simulated strengths of the investment strategy under the assumption of zero transaction costs, a rebalancing frequency of 20 trading days, an estimated risk aversion parameter of 2.5 and a five per cent uncertainty associated with the CAPM prior. Sensitivity analysis performed by examining how the results are affected by variations in these input variables has also shown notable differences in the sensitivity of the results obtained from the two models. While the performance of the Black-Litterman portfolio does undergo material changes as the inputs are varied, these changes are nowhere near as profound as those exhibited by the classical mean-variance portfolio.

     

    In the light of our empirical results, we also conclude that there are mainly two aspects which the portfolio manager ought to consider before committing to one model rather than the other. Firstly, the nature behind the views generated by the investment strategy needs to be taken into account. For the implementation of views which are of an α-driven character, the dynamics of the Black-Litterman model may not be as appropriate as for views which are believed to also influence the expected return on other securities. Secondly, the soundness of using market-capitalization weights as a benchmark towards which the final solution will gravitate needs to be assessed. Managers who strive to achieve performance which is fundamentally uncorrelated to that of the market index may want to either reconsider the benchmark weights or opt for an alternative model.

  • 13.
    Cecilia, Bill
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Improving anti-drug antibody assay performance in Gyrolab for therapeutic recombinant antibody Infliximab2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Monoclonal antibodies can be used as targeting therapies for several diseases. One major concern when using these therapies is anti-drug antibodies which may hamper the drugs efficiency. Gyrolab is an automated platform which can be used to develop bridging immunoassays where the anti-drug antibodies affinity towards the monoclonal antibody is utilized. Anti-drug antibody immunoassay development on Gyrolab is limited mainly by three factors which may inappropriately affect signal intensity levels. In this project different variants of bridging immunoassays based on drug Fab fragments have been developed for monoclonal antibody Infliximab, with the purpose to illustrate the effects of these three factors.

    Findings indicate that an assay based completely on drug Fab fragments is more sensitive compared to an assay based on intact drug since less affected by unspecific interactions between drug reagents and complex formations. Surprisingly findings also indicate that an assay based completely on drug Fab fragments is affected by human anti-hinge antibodies which decrease assay sensitivity. The most optimal assay variant is based on the combination between intact capture drug and Fab fragment as detection. This variant is insensitive to false positive reactions caused by Rheumatoid factor and human anti-hinge antibodies, less prone to form unspecific interactions between drug reagents and complex formations in the presence of anti-drug antibodies. The optimal assay variant also demonstrates best drug tolerance in combination with acid dissociation.

  • 14.
    Akhter Feroz, Raisin
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Climate Change Vulnerability Assessment for Sustainable Urban Development: A Study on Slum Population of Kota, India2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The urban centres are becoming more vulnerable to climate change because of the rapid urbanization and the inequality of urban development. This study assesses the urban vulnerability in an integrated approach focusing the slum people as the targeted group. The slum people are severely exposed to climate risks in terms of city‟s overall development. The negative indications of the indicators of person‟s vulnerability represent their high sensitivity to the adverse impact of climate change. The determinants of adaptive capacity also confirm that the slum people are more vulnerable to climate change with having lower adaptive capacity; though, the city is possessing high development indexes. In this context, an institutional structure is developed to build multi-level urban climate governance with the involvement of all relevant stakeholders based on the case study and literature review to integrate the vulnerable group in development planning for climate change adaptation.

  • 15.
    Skoglund, Martin
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Mårtensson, Cecilia
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Solar landfills: A study of the concept in a Swedish setting2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The increasing global energy demand, which today is mainly supplied by energy sources with a fossil origin, is a severe threat to the environment and to the security of supply. In order to handle these problems, renewable energy sources are promoted globally as well as nationally in Sweden. Solar photovoltaic (PV) technology is one of the most mature and commercial renewable energy technologies and could play a vital role in phasing out fossil energy sources. In the emerging, promising concept of solar landfills, PV systems are installed on closed landfill sites in order to combine renewable electricity production with resource efficient use of land. In this study the legal, technical and financial aspects concerning a solar landfill project in a Swedish setting were investigated. Additionally, the potential of the concept on a regional level in Sweden was analysed. The methodology used in the study featured literature research, interviews, and a feasibility assessment of a solar landfill project on Visby landfill.

    Regarding the legal aspects linked to a solar landfill project, an inconsistency between Swedish municipalities concerning the need of a building permit for a ground mounted PV system was revealed in the study. While some municipalities demand a building permit, others do not. Additionally, the fact that a closed landfill usually is classified as an environmentally hazardous activity doesn’t result in any need for additional permissions for a PV system installation on a closed landfill. Therefore, such legal aspects are not likely to hinder a solar landfill project to any great extent.

    Considering the technical aspects, the choice of mounting system must be done carefully because of the special conditions which exist on a landfill site; such as ground penetration restrictions and risks of settlement. While a ballasted mounting system can avoid ground penetration, a driven pile mounting system generally features a lighter construction. Furthermore, a fixed tilt mounting system is preferred over a sun tracking mounting system due to the extra weight and sensitivity to settlement which comes with the latter choice. Regarding the choice of PV modules, thin film modules generally feature a lower weight and can therefore be advantageous in comparison with crystalline silicon modules. In the case of Visby landfill, where penetration was preferred to be avoided but where the risk of settlement was considered low, the PV system which was deemed most suitable for the site featured a ballasted fixed tilt mounting system with crystalline silicon PV modules.

    Considering the financial aspects, the study emphasises the importance of using the produced electricity to offset consumed electricity in order to enable a sound investment. This can be done by a wise choice of owning and financing structure where the produced electricity offsets consumed electricity for a large consumer, e.g. an industry or a grocery store, or for a number of residences in a community solar. The economic feasibility also heavily depends on the projects’ possibility to use policy incentives and tax exemptions. The feasibility assessment of Visby landfill showed that the most economically feasible investment was possible by founding a community solar which offsets the members’ consumed electricity. Such an investment would feature a 10 year payback time and an internal rate of return of 8.3 %.

    Finally, the potential of the solar landfill concept on a regional level was identified as significant. In a scenario where the PV system suggested for Visby landfill in the feasibility assessment is installed on all the suitable landfill sites on Gotland, the island has the possibility to produce 22 GWh of electricity from solar landfills, thereby meeting the regional energy goal set for 2020.

  • 16.
    Mihaylov, Veselin
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Comparative life cycle impact assessment of a battery electric and a conventional powertrains for a passenger transport ferryboat: A case study of the entire integrated system for vessel propulsion2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis represents a life cycle impact assessment of a state of the art electrically driven power train. It is expected to be installed in a diesel engine passenger ferry boat, currently transporting passengers in downtown Stockholm archipelago. The assessment has a comparative character in between the currently operating and the new power train in order to differentiate and recognize which of the two propulsion options is the environmentally preferable choice.

    The scope of the study is directed towards the thorough examination of both power trains so that it can represent most closely the two specific technological cases. Studied and assessed were the three main life cycle phases of each power train – raw materials acquisition and manufacturing, use phase and end of life phase. The fundament of the study involved creating environmental models for each and every component of the drive trains, the propulsion fuel and energy used, and the services related to waste treatment in the last phase of their functional life. The environmental models were later used to build live cycle inventories that served to derive the respectful impact from the item analyzed. The data used to model the battery electric power train was provided directly from the manufacturer, where the end of life procedures carried out were assumed where possible. The main battery pack for the electric power train was not modeled in terms of  end of life procedures due to insufficiency of information. Almost no generic information was available to model the diesel engine and it was calculated by creating auxiliary simplified cad models. The rest of the data required to achieve an environmental inventory regarding the power train was available from a subcontractor. Both studied options were modeled with allocation approach that includes the avoided production of materials at the waste treatment stage where there was sufficient information to do that. There was none to model the main battery packs avoided production which is a major component of the battery electric system. To model the use phase of the diesel engine power train, research data regarding combustion emissions and waterborne emissions was utilized. A number of electricity mix models were applied to create a sensitivity analysis of the operation phase of the battery electric power train. Chosen for baseline scenarios simulating the use phases of both power trains are use of Nordel market electricity mix and the combustion of low sulfur diesel with five volumetric percent rape methyl ester additive.

    For the purposes of the assessment eighteen midpoint impact indicators were used to cover the areas of global warming potential, human health and quality of eco systems. The results from the study show that the estimated impact from both power trains is small enough to have almost no influence on the results from the two baseline scenarios. Based on this it was concluded that for future research of similar cases either generic information can be used or a cut-off can be applied. After the assessment, more environmentally favorable was estimated the diesel engine power train because of the large burdens from the battery manufacturing in the battery electric option. Further assessment determined that the diesel engine power train again is less environmentally intensive than the battery electric with the main battery burdens excluded. In the overall life cycle impact assessment both power train showed different results in the different impact categories, which could not place a definitive propulsion option of choice. The conclusions from the analysis are that the diesel engine power train causes higher impact in the categories related to global warming, fossil depletion and in most ecosystems quality indicators. The battery electric version in its base line scenario, on the other hand, expresses higher impact in categories related to human health and in the remaining eco system quality midpoint-scores.

  • 17.
    Harangi, Márta
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, Faculty of Arts and Sciences.
    Känslomässiga påfrestningar på medarbetarna vid arbete med ensamkommande flyktingbarn på ett HVBhem2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to explore the HVB staff's emotional strain associated with their work. The study is based on a phenomenological approach, using semi-structured interviews of ten employees. According to my results the personnel experienced working with unaccompanied minors as both rewarding and demanding. Social skills are the most important knowledge in this kind of work, but language and cultural competence are also desirable. Sensitivity and respect for other people are highlighted as central issues in this kind of work. The psychosocial environment is perceived as stressful. Workers use various coping strategies to manage their stress. The study concludes that work in the HVB home is mentally and emotionally stressful and strenuous, increasing the risk of mental illness.

  • 18.
    Nordström, Kjell
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    On the Trade-Off between Noise Sensitivity and Robustness for LQG-Regulators1984Report (Other academic)
    Abstract [en]

    A design method that makes a trade-off between noise reduction and stability requirements is suggested in the case when the process is modelled as a time invariant linear stable plant. Thesuggested controller is obtained by modifying the well known LQG-controller. Only the SISO-case is treated here. We give analytical expressions on how stability margins can be improved and how thestochastic properties will change using the suggested nonoptimal controller.

  • 19.
    Nordström, Kjell
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    On the Trade-Off between Noise Sensitivity and Robustness for LQG-Regulators1985Report (Other academic)
    Abstract [en]

    A design method that makes a trade-off between noise reduction and stability requirements is suggested in the case when the process is modelled as a time invariant linear stable plant. Thesuggested controller is obtained by modifying the well known LQG-controller. Only the SISO-case is treated here. We give analytical expressions on how stability margins can be improved and how thestochastic properties will change using the suggested nonoptimal controller.

  • 20.
    Daréus, Emma
    et al.
    Linköping University, Department of Computer and Information Science, Statistics. Linköping University, The Institute of Technology.
    Suhr, Hektor
    Linköping University, Department of Computer and Information Science, Statistics. Linköping University, The Institute of Technology.
    En undersökning av sambandet mellan kronisk inflammation och lungcancer2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Cancer is a big health problem in Sweden and one of the leading causesof death. As of recently there has been an increase in the interest in thecancer research community in how chronic inflammation influences theemergence of cancer tumors. In this paper we intend to investigate therelationship between markers of chronic inflammation and lung cancer.We will also look in to the possibility that sialic acid may be a marker oflung cancer.Lung cancer is one of the most common types of cancers in Sweden andhas a high mortality rate compared to other cancers. Reasons for thisbeing both from the fact that it is usually discovered at a later stage and islocated in a sensitive organ make it harder to treat.To do this we will use sialic acid as a marker of inflammation from acohort study done during the early sixties, it will be cross referenced withthe Swedish Cancer Registry from Socialstyrelsen. BMI and age will alsobe used as variables of interest.The method for the paper will use Cox Proportional Hazard Model toestimate the risk of sialic acid relating to the emergence of lung cancer.Sensitivity analysis will be used to consider the effects of smoking as aconfounder variable.The results show that there are reasons to believe that chronicinflammation may have a role in the emergence of lung cancer tumors.There is no evidence in this study that suggest that sialic acid is a goodmarker for an individual having lung cancer. Furthermore, BMI seems tohave a protective effect against lung cancer, but this would need furtherstudy to draw any real conclusions from.

  • 21.
    Liljeholm, Lina
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Electroacoustic evaluation of thin film piezoelectric resonators for frequency control and sensing applications2005Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Electroacoustic evaluation and characterization of thin film electroacoustic resonators operating in the low GHz frequency range has been performed. The measurements have been carried out with a network analyser and model parameters extractions have been performed with both ADS and MATLAB. This study includes evaluation of three equivalent circuit models of the resonators using two different extraction methods of the circuit parameters. Further, the characterization includes evaluation of a resonating biochemical sensor noise performance, as well as its short time stability as a function of various network analyser parameters. The latter include the intermediate frequency bandwidth and the sweep time of network analyser, for which optimal settings for further measurements have been found. Further, it is shown that the resonators have an high Quality factor, which together with the high frequency of operation yield an extremely high mass sensitivity. Finally, the resolution of the resonant sensors is estimated to be approximately up to 5 times better than the resolution of commercially available biosensors, when operated in liquid media.

  • 22.
    Jonsson, Hans
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Fiberoptisk kabelsensor för perimeterövervakning2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In both civil and military applications it is important to minimize the cost of surveillance and to cover large areas without patrolling. The sensor described in this thesis is designed to be a robust alternative to traditional surveillance systems by both being inexpensive and able to cover considerable distances.

    FOI(Swedish Defence Research Agency) is developing the technology for this sensor on commission from FMV (Defence Material Administration). In a previous master thesis [1] an earlier version of the sensor was evaluated and the design used in this thesis was formulated.

    The sensor is using the change of polarization as a measure of the mechanical perturbation on a standard optical fiber. Multiple test signals with different polarization are used to collect enough information to fully describe the fibers effect on the state of polarization. By comparing several of these descriptions the mechanical perturbation can be quantified. The polarimetric signal processing to extract this information is formulated within the scope of this thesis.

    A characterization of the components used in the sensor has been made and the results are presented in the report. The setup of the sensor was improved by adding a polarization beam splitter. This improvement was found necessary for the function of the sensor and to achieve a linear sensitivity. The polarization beam splitter allows simultaneous detection of orthogonal polarizations.

    Finally the characterizations and the signal processing were tested with a controlled mechanical strain and a field trial. After evaluating the trials it is evident that the evolution of the test signals polarization state can be monitored and that the Mueller matrix describing the fibers effect on the state of polarization can be formulated.

  • 23.
    Holmgren, Erik
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    UWB Measurement Techniques and RF Coexistence in a Mobile Handset2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    There are two typical interference problems in a multi-radio platform, i.e. blocking due to the saturation of the front end of a receiver by the high power radiation from another transmitter, and desensitization of the receiver by the in-band noise generated by the other transmitter. The UWB device is not an exception.

    In the coexistence study, two different development kits containing a UWB radio are investigated. The UWB devices cause a raised noise floor and generate severe spurious emissions into the receiver bands for GSM, UMTS, Bluetooth and 802.11b. Consequently this results in degradation of the sensitivity performance of these receivers. Based on measurements performed, the solution for this problem was found by inserting a band-pass filter or a high-pass filter at the transmit path of the UWB device.

  • 24.
    Fransson, Erik
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Hammargren, Dennis
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Nytta av trafikdetektorer och VMS för realtidsinformation på E6 i västra Skåne2005Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish road administration has plans of increasing the numbers of traffic detectors on E6 in the Skåne region for which there is a unproportionally high frequency of accidents. Due to this the administration has an interest in finding out how large the benefits are in using traffic detectors. The main object of this essay is to calculate the benefit of traffic detection systems and VMS on E6 for real-timeinformationusing a method developed by WSP Gothenburg. The method consists of the most important information systems for traffic detection, Internet, radio and VMS. These systems contribute to a benefit that appear for the road user before the journey and during the journey but also the benefit that appear in the handling of interruptions in traffic, the benefit of increase in knowledge in the road traffic control centre and the benefit of strategic planning.

    The method implies that different kind of data for the road is collected. An example of such data is how the road user value their time spent in traffic. Another example is the capacity of the road. Some data are easier to find than others. The margin of error also varies. In connection with the method formulas for calculating the benefit where developed by WSP. In these formulas deficiencies have been corrected and data have been adapted. Collected data is organised as the method suggests: before the journey, during the journey, interruption handling, knowledge in the road traffic control centre and strategic planning. There is also a group of general data.

    After calculations the resulting total benefit of traffic detection reached 15,7 million SEK per year. Surprisingly the benefit before the journey was significantly larger than the benefit during the journey. To examine how the variables influence the total benefit an analysis of sensitivity has been executed. It is recommended to concentrate most of the work of collecting data on the variables that plays a major role in the final outcome of the benefit. The differences between the sensitivity of the variables turned out to be large. In the end of the essay the result of the benefit is analysed. The benefit of appreciating information has a large share in the final result. Finally there are recommendations for further studies within this field.

  • 25.
    Henriksson, Marie-Louise
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Speech and Language Pathology. Linköping University, Faculty of Health Sciences.
    Troedsson, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Speech and Language Pathology. Linköping University, Faculty of Health Sciences.
    Samspel mellan föräldrar och deras 16-månaders barn: Kommunikativ utveckling i relation till mind-mindedness och föräldrasensitivitet2013Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The way a parent interacts with his or her child can have a great effect on communication and language development of the child. Maternal sensitivity and mind-mindedness are two measures used for parent-child interplay. Maternal sensitivity measures the parent’s ability to accurately perceive and interpret the child’s cues while mind-mindedness involves the parent’s use of words and comments regarding the child’s internal state. These comments can be classified as appropriate or non-attuned regarding the situation and the child’s state of mind. To what extent mind-mindedness and maternal sensitivity affect different parts of the child’s communicative development is still mainly unknown.

    The purpose of the present study was to investigate if maternal sensitivity and mind-mindedness co-vary with communicative abilities, if mind-mindedness and maternal sensitivity co-vary with each other, and finally, if any gender differences was present. The material of the study consisted of 35 videotaped parent-child interactions, which were observed when the children were 16 months of age. To measure maternal sensitivity, the sensitivity scale were used, “Sensitivity vs. Insensitivity to the Baby's Signals”. To measure mind-mindedness, parent-child interplay and parental interviews were coded. The child’s communicative abilities were assessed with the Swedish Early Communicative Development Inventories and with the Early Social Communication Scales.

    The result showed a correlation between maternal sensitivity and language comprehension, communicative gestures and joint attention. A relationship was found between mind-mindedness and parents’ using more non-attuned mental comments and children’s decreasing ability to respond to joint attention. The results also demonstrated that a sensitive parent uses more appropriate mental comments than a parent who was insensitive. A reversed relationship was found between non-attuned mental comments and a low level of maternal sensitivity, where the insensitive parent used more non-attuned mental comments. Finally, a difference in gender was found, where parents use more non-attuned comments to boys than to girls. 

  • 26.
    Eterovic, Mirko
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Özgül, Simge
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Study of a Country Level Facility LocationSelection for a Small Company2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Selection of an optimal facility location is a challenging decision for companies, since it would be costly and dicult to change the location after an installation has been already made. Existing numerical methods in the decision-making process help companies to perform their operations with minimum cost and maximum value based on their strategic objectives.

    Decision making process requires the selection of relative processes among several alternatives corresponding to a set of location factors. It can be performed by multi criteria decision-making (MCDM) methods with the point of individuals or a group of decision makers.

    This study provides a suitable country selection process for a new packaging facility location problem. The problem is formulated by using a combination of fuzzy AHP and TOPSIS, which are the methods for MCDM problems. Since the available information for weighting the factors is subjective and imprecise, fuzzy AHP is used for determining the relative importance of the factors. Afterwards to select the best suitable country, the scores of alternatives are quantied by means of TOPSIS method. Later the results are presented, and the obtained solutions are discussed. Latvia is found as the best country for the new packaging facility. Further, using sensitivity analysis we found that the most stable countries according to predetermined factors were Latvia and Poland.

  • 27.
    Yi, Qian
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Vehicle Ownership and Fleet models2011Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Vehicle ownership model is an important tool in finding tax strategies as well as reducing the pollution effects based on the forecast results from the model. However, the limitations and shortcomings of the existing vehicle ownership models lead to the low quality forecast in some aspects.

    Therefore, the thesis surveys the vehicle ownership models as well as vehicle fleet models. The research is mainly about the car ownership and fleet model. The currently used car ownership models in Europe are listed and four models are introduced briefly, including their advantages and disadvantages. The relationship between vehicle ownership and fleet models are also described.

    One specific car ownership model is used for numerical test. The tested car ownership model is the sub-model in Sampers’ in Sweden. This model consists of individual entry and exit probability of car ownership. The estimation data is the same as the data used in Matstoms (2002), which includes the information of the number of cars for different age, gender, income level, and the petrol price, GDP, from 1980 to 1995 in Stockholm, Solna and Sundbyberg. The software used for model estimation is SPSS.

    The following part is to validate the estimation results and find out the sensitivity of each variable by doing forecasting in Stockholm from 1996 to 2010. The sensitivity analysis shows that the car ownership in Stockholm is most sensitive to petrol price and least sensitive to GDP. We recommend removing the GDP variable and test it by using chi-square test. The chi-square test shows that the GDP variable can be removed from the model.

    Keyword Vehicle ownership, Vehicle fleet, Car ownership, SPSS, Sampers, Nonlinear regression analysis.

  • 28.
    Korishe, Abdulah
    Linköping University, Department of Electrical Engineering, Electronics System.
    A Driver Circuit for Body-Coupled Communication2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The main concept of Body-Coupled Communication (BCC) is to transmit the electrical information through the human body as a communication medium by means of capacitive coupling. Nowadays the current research of wireless body area network are expanding more with the new ideas and topologies for better result in respect to the low power and area, security, reliability and sensitivity since it is first introduced by the Zimmerman in 1995. In contrast with the other existing wireless communication technology such as WiFi, Bluetooth and Zigbee, the BCC is going to increase the number of applications as well as solves the problem with the cell based communication system depending upon the frequency allocation. In addition, this promising technology has been standardized by a task group named IEEE 802.15.6 addressing a reliable and feasible system for low power in-body and on-body nodes that serves a variety of medical and non medical applications.

    The entire BAN project is divided into three major parts consisting of application layer, digital baseband and analog front end (AFE) transceiver. In the thesis work a strong driver circuit for BCC is implemented as an analog front end transmitter (Tx). The primary purpose of the study is to transmit a strong signal as the signal is attenuated by the body around 60 dB. The Driver circuit is cascaded of two single-stage inverter and an identical inverter with drain resistor. The entire driver circuit is designed with ST65 nm CMOS technology with 1.2 V supply operated at 10 MHz frequency, has a driving capability of 6 mA which is the basic requirement. The performance of the transmitter is compared with the other architecture by integrating different analysis such as corner analysis, noise analysis and eye diagram. The cycle to cycle jitter is 0.87% which is well below to the maximum point and the power supply rejection ratio (PSRR) is 65 dB indicates the good emission of supply noise. In addition, the transmitter does not require a filter to emit the noise because the body acts like a low pass filter.

    In conclusion the findings of the thesis work is quite healthy compared to the previous work. Finally, there is some point to improve for the driver circuit in respect to the power consumption, propagation delay and leakage power in the future.   

  • 29.
    Pettersson, Anders
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Development of water leakage detectors2008Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    One of the highest costs in many apartments for insurance companies is due to water leakage. To prevent leakage from causing damage a detector can be placed in the sensitive areas to warn if a leakage should occur. This kind of installations does however lead to high installation costs, especially in already finished buildings, since they require a lot of wiring for communication.

    By using a wireless detector these costs could be lowered. In order for this to be achieved a sensor which is suitable to detect such water leakage has been connected to a wireless ZigBee transmitter which in turn is able to connect to a wireless network. The advantage with using ZigBee is that it provides much better range for less power compared to other solutions. The hardware includes a circuit that modulates the input from the sensor to have a more distinct behavior. The software part handles the communication with the ZigBee network and processing of the modified input from the sensor. To achieve a reasonable sensitivity of the sensor a circular buffer has been created to trigger on an average value instead of instantaneous. After reaching a satisfying design all parts were manufactured and tested to ensure that they work according to the design. In the course of the work some ways of improvements were found and implemented, resulting in a well working prototype.

  • 30.
    Neumann Radpour, Nicole
    Linköping University, Faculty of Health Sciences.
    Test av litiumheparinplasma för analys av folat med Siemens Advia Centaur® XP samt effekt av inomhusbelysning över tid2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: Folate is a water - soluble vitamin necessary for normal DNA synthesis among  other mechanisms. Folate deficiency can cause megaloblastic anemia resulting from abnormal erythrocyte d evelopment. At the Department of Clinical Chemistry, Linköping, analysis of folate is performed with Siemens ADVIA Centaur® XP which uses an immunochemical method with chemiluminimetric detection. Currently, the assay is conducted on serum, is poured off and frozen after 48 h and treated with light protection because folate is considered to be light sensitive.

    Methods: This study tested lithium heparin plasma for analysis of folate with Siemens ADVIA Centaur® XP with the aim to be able to perform a package of analyzes in anemia investigation from the same collection tube. Furthermore, the stability of folate was studied for up to 168 h and examined regarding light sensitivity.

    Results: Statistically significant higher values were obtained in the analysis of folate in lithium heparin plasma than folate in serum (p < 0,001). Serum folate was found to be stable up to 168 h and plasma folate was stable up to120 h. No statistically significant difference was found either between the serum or plasma folate regarding light exposure.

    Conclusion: Folate cannot be analyzed on lithium heparin plasma with the same reference range for serum folate, and further studies and a new reference range for plasma folate are needed to decide whether folate allows to be analyzed in plasma. Collection tubes for determination of folate in serum do not need to be light protected or poured off and frozen after 48 h which simplifies sample handling, reduces errors by relabeling and results in increased prospective automatized handling.

  • 31.
    Viberg, Mats
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Sensitivity of Parametric Direction Finding to Colored Noise Fields and Undermodeling1993In: Signal Processing, ISSN 0165-1684, E-ISSN 1872-7557, Vol. 34, no 2, 207-222 p.Article in journal (Refereed)
    Abstract [en]

    A fundamental assumption for most direction finding algorithms is that the spatial correlation structure of the background noise (i.e., the correlation from sensor to sensor) is known to within a multiplicative scalar. In practive, this is often achieved by measuring the array covariance when no signals are present, a procedure which is unavoidably subjected to errors. The presence of undetected weak signals gives rise to similar perturbations. In this paper, the effect of such modeling errors on parametric estimation techniques is examined. First-order expressions for the mean square error (MSE) of the parameter estimates are derived for the deterministic and stochastic maximum likelihood methods and the weighted subspace fitting technique. The spatial noise correlation structures that lead to maximum performance loss are identified under different assumptions. In case of high signal-to-noise ratio, it is found that the MSE can be increased by a factor equal to the number of sensors in the array, as compared to spatially white noise. Furthermore, it is demonstrated that the presence of a relatively weak (− 15 dB) undetected signal can result in a large bias (≈1°) on the estimates of the other signal directions.

  • 32.
    Käck, David
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Lindström, Eric
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Analysis of car simulator data2008Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Simulators are being used for a wide variety of purposes, not least for vehicle simulation as an aid in driver behaviour analysis. Common values to be measured are reaction times such as brake and steer reaction time. One problem with monitored simulator studies is that there are a limited number of test drivers. With only 50-100 test drivers, presented reaction times from the studies are often mean values. From a safety analytic perspective, it would be more interesting to show the entire distribution of values. The unmanned simulator at Universeum gives a large number of test drivers (~40k / year) which makes it possible to investigate entire distributions of values.

    Another benefit with the unmanned study at Universeum is that drivers tends to act more natural than in a monitored study, where drivers are aware of that they are being observed. On the other hand, the fact that users are not being observed, lead to a lot of questionable data. Drivers are exploring and do not behave as they would in real traffic.

    The main objective with our thesis project has been to find algorithms to extract trustworthy data from the simulator. It has been proven that there are large amounts of data that can be used for driver behaviour analysis. Methods to calculate common measures used in traffic safety analysis have been developed.

    An updated simulator software, better adjusted for an unmonitored study, has been developed and installed in the Universeum simulator. Summaries from the different scenarios in the simulator

    K2 Summary There are quite few drivers in the K2 scenario where a brake signal has not been registered at all. This is the main issue with the scenario and the explanation to this is that the scenario is very sensitive to the speed kept by the user. Speeding drivers will not experience the situation at all and since so many drivers are speeding, a lot of data is lost. By adapting the speed of the mover to the speed of the driver this problem would be reduced. The sensitivity to speed is also noticeable in the plots as the BRT seems to have very little influence on the results. The BRTs span from ~0.4 seconds to 2 seconds which is in range with other studies. [P1] There are some drivers steering but they are not many enough to draw any valid conclusions.

    K3 Summary The K3 scenario works much better than the other crossing scenarios, producing measurable data at a much higher rate than the other scenarios. This is probably thanks to the MeetAtPoint function which takes the drivers speed into consideration. The wider acceptance to speeds in the scenario gives better possibilities to analyse the impact of BRT and deceleration on the result. There are some drivers steering but they are too few to present any valid distributions.

    K5 Summary This scenario gives the least percentage of valid files among the K-scenarios. This is due to the very high urgency in the scenario. This together with the fact that the speed of the mover is not adapted to the speed of the driver allows very few drivers to actually experience the scenario at all. By adapting the speed of the mover to the speed of the driver, drivers will be able to experience the situation at a much higher rate than before. There are very few drivers steering instead of braking. Interesting is that, remembering that there are very few entries to investigate, the steering option has been quite successful in this scenario compared to the other K scenarios.

    U1 Summary The percentage of valid files from this scenario is at the same level as the other scenarios, i.e. quite low. The reason to the low percentage in this scenario is however not the speed kept. One big loss is the drivers which chooses to overtake the braking lead car and therefore fails to enter the situation as intended. The other problem is the distance between the lead car and the driver. The distance between them as the lead car brakes varies a lot and the BRT´s will therefore also vary. There are almost no drivers that try to steer away from the car instead of braking.

    U4 Summary The percentage of files where a brake signal has been registered is in level with the other scenarios. One explanation to the few registered brake signals is, as in the U1 scenario, that a lot of drivers choose to overtake the lead car and will therefore not experience the scenario at all. Overall the U4 data and results are questionable. Even when normalising the BRT by TTC no satisfying distributions can be found. The amount of files holding the U4 scenario (1761 or 23 % of all scenario files) are also remarkable high. And apart from the files holding a full scenario, there are a lot of files that holds only U4 start messages without any stop messages. This indicates that the U4 trigger points are trigged even when they are not supposed to. This will be investigated and discussed in chapter 3.1.5. There are a few drivers steering, an option that has proven quite successful in this scenario.

    M1 Summary The urgency in the scenario is low, which makes it possible for drivers to avoid a collision without steering. The lane position does not play any significant role on the type of reaction, but many drivers have a lane position to the right. A high amount of drivers have an offset which gives them a position more than 0.5 meters out on the road verge. The road verge is 3.2meters wide, which is much wider than in reality. The explanation to the high number of drivers that drives on the road verge can be that the width of the lane (3.2 meters) corresponds to the width of a road with speed limit 70km/h. Drivers may experience the road as narrow at a speed around 90km/h and therefore sometimes choose to drive on the road verge, which looks perfectly fine to drive on. [D] If the verge were less wide and looked less appealing to drive on this behaviour would probably be reduced. In reality the road verge on a road with a speed limit of 90km/h is 50cm. [I5]

    It was not possible to use the SWRR measure to analyse the driver behaviour. The SWRR is higher on parts of the road where it is more difficult for the driver to follow the road as in long turns. The SWRR increases linear as the speed increases but are too spread to make any conclusions from.

    M2 Summary The urgency in the scenario is high. It is hard to avoid a collision without steering. The lane position does not play any significant role on the type of reaction, but many drivers have a lane position to the right. It is not a normal behaviour to drive on the road verge and the meeting situation occurs in a left curve and a lane position to the right is not expected as many drivers would like to cut the curve, giving a lane position to the left. Despite the initial lane position, the most common type of reaction is steering right. 3,6% of all drivers are out on the grass (out of road). This can be considered as a high amount and probably depends on the wide road verge and the flat grass area, which looks perfectly fine to drive on. As in the M1 scenario, the wide, fully driveable, road verge is probably the reason to why 78% of the drivers choose to drive a least 50cm out on the road verge as they try to avoid the situation. Another explanation to the high number of drivers that drives on the road verge can be that the width of the lane (3.2m) corresponds to the width of a road with speed limit 70km/h. Drivers may experience the road as narrow at a speed around 90km/h and therefore sometimes choose to drive on the road verge, which looks perfectly fine to drive on. [D]

    It was not possible to use the SWRR measure to analyse the driver behaviour. The SWRR is higher on parts of the road where it is more difficult for the driver to follow the road as in long turns. The SWRR increases linear as the speed increases but are too spread to make any conclusions from.

  • 33.
    Grabowska, Kamila
    et al.
    Linköping University, Department of Management and Engineering. Linköping University, Faculty of Arts and Sciences.
    Tabe Mohammadi, Shideh
    Linköping University, Department of Management and Engineering. Linköping University, Faculty of Arts and Sciences.
    Ex-ante Control Mechanisms against Opportunistic Behavior regarding Knowledge Sensitivity of Product (Comparative Case Study)2013Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    There is an increasing interest for business organizations to engage into the global inter-firm alliance nowadays. The companies are striving for accessing the opportunities created by emerging markets, diversification of the products’ offer or the access to lower cost inputs (Barnes, et al., 2010). However, along with the benefits, there are also risks that the inter-firm alliances are challenged with. Those risks are represented by various forms of opportunistic behavior, which might be further caused by business partners (Williamson, 1975). The companies that decide to engage into inter-firm alliance need to invest in the implementation of control mechanisms that will protect them against opportunistic behavior. The preventing exante mechanisms can be implemented prior to the official start of cooperation while the cause ex-post mechanisms are applied during further stage of the collaboration. However, due to the cost of these implementations, companies cannot afford employing every available control mechanism. They need to select only the ones that their benefits exceed their costs. One of the main factors that influence the selection process of control mechanisms is the level of knowledge sensitivity of a product. The main objective of this master thesis is to determine how the level of knowledge sensitivity of a product influences the selection of ex-ante control mechanisms.

  • 34.
    Jansson, Anders
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gyrostudy - Development of a gyroplatform2007Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis has been carried out at Avantel AB where the assignment was to design hardware and software and with the aid of these collect data from gyro sensors. Because the industry demands lesser and cheaper sensors with increased precision new methods compensating for drift and temperature sensitivity are required. Methods that necessitate extensive evaluation and testing.

    The project began with a market overview of existing gyro sensors where certain characteristics such as drift and offset were examined. The next phase included design of hardware where amplifiers, power supply and A/D conversion are the major parts. Also, Universal Serial Bus, USB were implemented for connectivity. Software with the purpose of controlling the USB circuit and writing collected data to file was developed.

    This project run from September 2006 to January 2007 with the result of a working measurement instrument and collected data according to the criteria’s that was set.

  • 35.
    Paszowski, Michael
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Modeling of RF-design at board level for Assisted Global Positioning System (AGPS)2007Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis describes the design of a 1575.42 MHz Low-Noise Amplifier (LNA) using a Hetero-Junction Field Effect Transistor (HJ-FET) from NEC. The LNA design focuses on a minimum noise figure and good power gain in order to improve receiver sensitivity. The first evaluation of the LNA module shows a good agreement between the simulated and measured results. However, the output matching section has some deviation from the reflection coefficient against the simulated results, which in turn led to a minor redesign of the output matching network. Touchstone parameters representing a via and a SubMiniature version A (SMA) connector were extracted from measurements using Matlab and verified in Microwave Office.

    The LNA prototype has a measured gain of 15.54 dB, a noise figure of 0.80 dB. The receiver minimum detectable signal level with SAW-filter is decreased from -159.15 dBm using the Infineon BGA615L7E6327 Silicon Germanium GPS Low-Noise Amplifier to -159.40 dBm.

  • 36.
    Sammelin, Peter
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Energy effective houses2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis is produced in corporation with Älvsbyhus representative in Östergötland. Älvsbyhus is for the moment the largest manufacturer of prefabricated detached timber houses in Sweden.

    A prognosis from the Swedish environmental protection agency and the Swedish energy agency suggests that the discharge of greenhouse gases will increase rapidly until 2020. The prognosis concludes that all energy use affects the environment to some extent and energy efficient buildings can contribute to a reduction of the greenhouse effect. The Swedish government are using economical and administrative instruments of control to guide the building companies and property owners. The Swedish building regulations concerning energy management has since 1 July 2006 been sharpened and the law of buildings energy performance will come into force in October 2006.

    The National Board of Housing, Building and Planning (BBR) has in the report “Piska och morot” concluded that it is impossible to estimate the socio economic potential of energy efficient buildings. The private economic potential can on the other hand lead to a decreased sensitivity to fluctuating energy prices. BBR’s report also suggests that the measurements could lead to an increased awareness and make energy efficiency to an important argument in project planning and marketing of buildings. Scientists working with energy matters are recommending a line of thought that means an increased focus on a reduction of energy losses through the building envelope. The building envelope should in other words have sufficient thermal insulation and protection against air leakage. The last step in the process would be to dimension the heating system after the remaining heating demand.

    The purpose with this study is to investigate how the building envelope on prefabricated houses of timber is constructed concerning rational use of energy. The results of the study are meant to lead to an increased knowledge about the technical level of our newly built houses and possible actions to decrease the energy use by changing the building envelope. The report begins with a theoretical section that explains the background and problems concerning energy effectiveness. The theoretical section is also meant to help the reader with an introduction in terminology, basic building physics and mechanisms that effects the heat requirements. The practical section of the report is a study of model houses from six of  Sweden’s largest manufacturers of detached timber houses.

    A simulation programme (ENORM 2004) has been used to calculate the thermal needs for the model houses. The results from the calculations are used to decide if the model houses are following present (BFS 2002:19) and future (BFS 2006:12) building regulations (BR). The present regulations concern the total heat transfer coefficient (F s = Um (W/m2K)) and future regulations concern the specific energy use (kWh/m 2 · year). The model houses will also be compared to identify differences in construction and calculation results that has an effect on the heat requirements. Houses that do not live up to the BR will be submitted to changes in the building envelope until they meet the regulations. To conclude the practical section of the report the model houses will be provided with qualities from low energy houses. The purpose is to determine how the heat requirement is effected with extreme changes in the building envelope.

    The results from the calculations (see table’s below) show that all model houses meet up to present building regulations. Future building regulations prescribe that Sweden will be divided into two climate zones separated on a level with the city of Karlstad. All model houses met up with the demands for the southern climate zone and none of the model houses met up with the demands for the northern zone. In the calculations Stockholm represents the southern zone and Luleå represents the northern zone.

     

  • 37.
    Silverin, Gustav
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Europaväg 22 genom Söderköping - En stokastisk köanalys2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The main purpose of this thesis is to confirm the suspected lack in traffic capacity for the thoroughfare in the town Soderkoping. This report is mainly made up by two parts. In the first the current situation with traffic problems in Soderkoping is analyzed and a presentation of the problems that occur due to the limitations of the infrastructure is given. In the second part, different possibilities of future development in the traffic flows are analyzed by implementing different scenarios with a Mat Lab-model. With the help of the model the sensibility of the different traffic flows are also established. A red thread through out the report is that of the use of stochastic queuing theory. One of the goals with the report is to investigate how capable the theory is on describing how queues develop and discharge in signalized intersections. To achieve this has new measurements to calculate the capacity in intersections been created. For instance, the calculation of a breaking-point in level of traffic flow that, when acceded, gives an instable queue growth. Furthermore the possibility of using the technique more direct, as in for example aiding the control of logical rules for shifting between signal phases is looked at.

    The results show that the infrastructure of today will not be enough in the future. The different scenarios and analyzes show that it is the primary traffic flows on the E22 that are more sensitive to an increase of flow levels and that the flows on the secondary streets can increase relatively much without any appreciably reduction of the accessibility of the junction. Another conclusion is that it is possibly with the aid of detectors to guide the prioritizing of phrases in traffic signal installations when the deployment of the detectors and the logic of the control system are established by using stochastic queuing theory on the different traffic streams. More traffic programs and better governing of the existing, with enhanced sensitivity and greater use of all programs, will increase the capacity of signalized intersections, in both total accessibility and the ability to prioritize the discharge of long queues.

  • 38.
    Cresswell, James E.
    et al.
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Page, Christopher J.
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Uygun, Mehmet B.
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Holmbergh, Marie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology.
    Li, Yueru
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Wheeler, Jonathan
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Laycock, Ian
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Pook, Christopher J.
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Hempel de Ibarra, Natalie
    Psychology, College of Life and Environmental Sciences, University of Exeter, Washington Singer Building, Perry Road, Exeter EX4 4QG, United Kingdom.
    Smirnoff, Nick
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Tyler, Charles R.
    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom.
    Differential sensitivity of honey bees and bumble bees to a dietary insecticide(imidacloprid)2012In: Zoology (Jena), ISSN 0944-2006, Vol. 115, 365-371 p.Article in journal (Refereed)
    Abstract [en]

    Currently, there is concern about declining bee populations and the sustainability of pollination services.One potential threat to bees is the unintended impact of systemic insecticides, which are ingested bybees in the nectar and pollen from flowers of treated crops. To establish whether imidacloprid, a systemicneonicotinoid and insect neurotoxin, harms individual bees when ingested at environmentally realisticlevels, we exposed adult worker bumble bees, Bombus terrestris L. (Hymenoptera: Apidae), and honeybees, Apis mellifera L. (Hymenoptera: Apidae), to dietary imidacloprid in feeder syrup at dosages between0.08 and 125 g l−1. Honey bees showed no response to dietary imidacloprid on any variable that wemeasured (feeding, locomotion and longevity). In contrast, bumble bees progressively developed overtime a dose-dependent reduction in feeding rate with declines of 10–30% in the environmentally relevantrange of up to 10 g l−1, but neither their locomotory activity nor longevity varied with diet. To explaintheir differential sensitivity, we speculate that honey bees are better pre-adapted than bumble bees tofeed on nectars containing synthetic alkaloids, such as imidacloprid, by virtue of their ancestral adaptationto tropical nectars in which natural alkaloids are prevalent. We emphasise that our study does not suggestthat honey bee colonies are invulnerable to dietary imidacloprid under field conditions, but our findingsdo raise new concern about the impact of agricultural neonicotinoids on wild bumble bee populations.

  • 39.
    Ross, Steffen
    et al.
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Faculty of Health Sciences.
    Ebner, Lukas
    University of Bern, Switzerland .
    Flach, Patricia
    University Hospital of Zürich, Switzerland and University of Zurich, Switzerland .
    Brodhage, Rolf
    Roentgen Institut Brunnhof, Bern, Switzerland.
    Bolliger, Stephan A.
    University of Bern, Switzerland .
    Christe, Andreas
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Faculty of Health Sciences.
    Thali, Michael J.
    University of Zurich, Switzerland .
    Postmortem Whole-Body MRI in Traumatic Causes of Death2012In: American Journal of Roentgenology, ISSN 0361-803X, E-ISSN 1546-3141, Vol. 199, no 6, 1186-1192 p.Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE:

    The aim of this study was to determine the sensitivity and specificity of postmortem whole-body MRI for typical injuries resulting from traumatic causes of death.

    MATERIALS AND METHODS:

    Forty cases of accidental death were evaluated with postmortem whole-body MRI. Imaging was conducted according to a standard protocol, and each examination had an average duration of 90 minutes. The imaging findings were correlated with the autopsy findings, which served as the reference standard.

    RESULTS:

    MRI showed the main pathologic process leading to death in 39 of the 40 cases. The sensitivity of postmortem MRI ranged from 100% (pneumothorax) to 40% (fractures of the upper extremities). In general, MRI had a high level of performance for depicting soft-tissue lesions, such as subcutaneous hematoma (e.g., galeal hematoma with a sensitivity 95%). The sensitivity of MRI was remarkably lower for lesions of the upper abdominal organs (liver, 80%; spleen, 50%; pancreas, 60%; kidneys, 66%).

    CONCLUSION:

    Postmortem whole-body MRI had overall good performance for depicting traumatic findings in corpses and therefore may serve an important role as an adjunct to classic autopsy for the forensic examination of cases of traumatic cause of death. However, the reduced sensitivity of postmortem MRI for lacerations of the upper abdominal organs and the observed superimposition of antemortem findings and postmortem findings (e.g., in the pulmonary tissue) in this retrospective study suggest that whole-body postmortem MRI not be recommended as a replacement for classic autopsy.

  • 40.
    Johansson, Siri
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Lethagen, Elin
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Fonologisk bedömning baserad på bildbenämning jämfört med spontantal av barn med fonologisk språkstörning2012Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In a phonological assessment, the aim is to obtain systematic and reliable data of a child's speech output, which can then serve as a basis for a decision on an appropriate intervention (Wolk & Meisler, 1998). Whether phonological assessment should be derived from an analysis of picture-naming or a conversation with the child, and whether the two methods for elicitation generate equivalent results, has been debated among clinicians and researchers for an extended time (Masterson, Bernhardt & Hofheintz, 2005).

    The aim of the present study was to compare two methods of speech elicitation for phonological assessment: spontaneous conversation and picture-naming, respectively. In the study, the procedures have been used when assessing children with phonological disorders as well as children with typical language development. The results are presented using two levels of phonological analysis; degree of phonological impairment, in terms of percentage of phonemes correct (PPC), and type of phonological impairment, in terms of phonological simplification processes. Eighteen (18) children participated in the study, nine (9) with phonological impairment (age 3;10 – 5;11), and nine with typical phonologic development (age 3;2 – 4;6). No significant differences were found regarding the percentage of phonemes correct between the two elicitation methods, neither for the group of children with phonological impairment, nor for the group of children with typical phonological development. Thus, the degree of speech difficulties was the same regardless of elicitation method. In assessing the type of impairment, however, a comparison between the sensitivity and the specificity obtained in the two tests indicate that there is a difference in how well the two elicitation methods intercept the phonological simplification processes. In the two elicitating methods, exactly the same processes could not be found in the speech of any child. The discussion includes the consequences of word structure, position and context of phonemes in the different speech samples. Furthermore, advantages and disadvantages of using the different elicitation methods in phonological assessment are discussed.

    The present study contributes to an increased knowledge about the ability to capture phonological problems sing picture-naming and conversational speech samples, respectively, in assessing a child’s speech. Furthermore, the study presents input to the on-going debate on phonological assessment, and may contribute to reflectance when selecting a clinical assessment tool.

  • 41.
    Karlson, Martin
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, Faculty of Arts and Sciences.
    Assessing GIS-based indicator methodology for analyzing the physical vulnerability of water and sanitation infrastructure2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Climate related problems such as droughts, heat waves, increased levels of precipitation and storms threaten the functionality of several infrastructural systems. This thesis focus on infrastructure that provides for water and sanitation services because it has been identified as being particular at risk when the climate is changing. The identification and mapping of the vulnerability of a system can improve the prerequisites to choose more appropriate measures to facilitate the situation at hand. In this study a set of GIS based methodologies using indicators (simple and composite) of vulnerability are proposed and assessed. “Physical” vulnerability is used as a measure combining the intrinsic characteristics of a system and the climate related hazard resulting in a measure for physical vulnerability. GIS software is used to manage the spatial data sets and to combine the indicators into indexes of physical vulnerability. The assessed systems and related climate hazards are: - Water and sewage pipe network and an increased risk of pipe breakage due to increased frequencies of landslides and – An increased risk for ground and surface water supplies related to pollution from the point sources sewage infiltration and polluted ground”. The resulting GIS applications are tested on pilot areas located in the Stockholm region and GIS based sensitivity analyses are performed. The availability and accessibility of relevant digital spatial data is also assessed and discussed.

  • 42.
    Rudeklint, Hanna
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Kostnadsnyttoanalys för malmtransporter från Kaunisvaara2012Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to do a Cost/Benefit analysis (CBA) treating the iron ore transports that follow the opening of the mine just outside the village Kaunisvaara in the northern part of Sweden. The mine and prospect company Northland Resources plan to start the mining in the fall of 2012 and the first iron ore transports are scheduled to the beginning of 2013. The mining company will use the port in Narvik, Norway, as their shipping point, which will radically increase the number of transports between Kaunisvaara and Narvik. In the opening years, Northland Resources plan to have an output of 1-4 million tonnes of iron ore per year until 2017. After that, the company has planned a full production rate of 4,7 million tonnes per year until at least 2037, since the company has secured production for a minimum of 25 years.

     

    The transport route to the port in Narvik consists of both railway and country road. The first part, between the mine around Kaunisvaara to Svappavaara, consists only of country road, while the rest of the way from Svappavaara to Narvik will depend on railway traffic. The country roads are not dimensioned for the amount of truck traffic that is required to transport all of the iron ore (a truck every seventh minute), therefore a CBA is a good way to map out how different solutions will affect the welfare of society. This CBA will treat alternatives concerning railway and electric roads, matched against a traditional truck traffic solution. To gain a more reliable result, the sensitivity analysis will include Monte Carlo simulation, in order to cover the uncertainties in the calculation in a better way. In the simulation, some distinct figures are replaced by probability distributions. The basic calculation is recalculated 1500 times, based on the random figures generated in accordance with the particular probability distribution for every effect.

     

    The basic calculation shows that the electric road alternative generate the most welfare relative to investment cost, while the railway alternative would have increased the welfare about 1,7 billion SEK more than the electric road alternative, purely in monetary effects. After simulation, the electric road alternative was found the most profitable for society. Although, since the transhipment costs from truck to railway at Svappavaara are not included in the calculation, the conclusion is that the railway alternative is the recommended alternative based on the results of this thesis.

  • 43.
    Sarrafchi, Amir
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Olfactory sensitivity of human subjects for six predator odorants2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of the present study was to determine olfactory detection thresholds in human subjects for a set of six sulfur-containing odorants which are known to be components of mammalian predator odors. Using a threealternative ascending staircase procedure, the olfactory sensitivity of 12 healthy adult human subjects, 6 males and 6 females was assessed with 2-propylthietane, 2,2-dimethylthietane, 3-mercapto-3-methylbutan-1-ol, 3-mercapto-3- methylbutyl formate, 3-methyl-1-butanethiol, and methyl-2-phenylethyl sulfide. The results showed that A) all six predator odorants were detected at concentrations below 1 ppb (parts per billion), and one of them (3-mercapto-3-methylbutyl formate) even at a concentration below 1 ppt (parts per trillion), B) structurally similar odorants yielded significantly different threshold values, and C) no significant sex differences were found in olfactory sensitivity with any of the six odorants. The findings obtained from the present study show that human subjects were not generally less sensitive to the predator odorants tested here compared to spider monkeys despite having a markedly lower number of olfactory receptor types. Further, they suggest that humans may be more sensitive to predator odorants compared to a variety of non-predator odorants. One possible explanation for the high olfactory sensitivity observed here is the fact that sulfur compounds typically can be detected at low concentrations. An alternative explanation derives from an evolutionary perspective as our human ancestors were a potential prey of large carnivores and  thus a high olfactory sensitivity for predator odors should be adaptive for humans.

  • 44.
    Thorslund, Lisa
    et al.
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Health Sciences.
    Falk, Magnus
    Linköping University, Department of Medical and Health Sciences, General Practice. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Primary Health Care Centres. Östergötlands Läns Landsting, Local Health Care Services in the West of Östergötland, Unit of Research and Development in Local Health Care, County of Östergötland.
    Patient performed reading of a phototest - a reliable method?2012In: Journal of Analytical Oncology, ISSN 1927-7210, Vol. 1, no 1, 81-87 p.Article in journal (Refereed)
  • 45.
    Gebreyohannes, Fikre Tsigabu
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Design of Ultra-Low Power Wake-Up Receiver in 130nm CMOS Technology2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Wireless Sensor Networks have found diverse applications from health to agriculture and industry. They have a potential to profound social changes, however, there are also some challenges that have to be addressed. One of the problems is the limited power source available to energize a sensor node. Longevity of a node is tied to its low power design. One of the areas where great power savings could be made is in nodal communication. Different schemes have been proposed targeting low power communication and short network latency. One of them is the introduction of ultra-low power wake-up receiver for monitoring the channel. Although it is a recent proposal, there has been many works published. In this thesis work, the focus is study and comparison of architectures for a wake-up receiver. As part of this study, an envelope detector based wake-up receiver is designed in 130nm CMOS Technology. It has been implemented in schematic and layout levels. It operates in the 2.4GHz ISM band and consumes a power consumption of 69µA at 1.2V supply voltage. A sensitivity of -52dBm is simulated while receiving 100kb/s OOK modulated wake-up signals.

  • 46.
    Andersson, Fräs Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Solid-phase microextraction for determination of background levels and point-source emissions of volatile sulfur compounds in the bioindustryManuscript (preprint) (Other academic)
    Abstract [en]

    The present study was conducted to develop a rapid, matrix-independent technique for simultaneous analysis of nine different volatile sulfur compounds (VSCs) in complex gas matrices.The potential of using solid-phase microextraction (SP:ME) in this context was investigated, and, to achieve the best sensitivity and avoid artifact formation and competitive adsorption, pel'formance ofthe following fiber coatings was tested: Carboxen/polydimethylsiloxane (CARIPDMS),divinylbenzene/ polydimethyl-siloxane (DVBIPDMS), and Carboxen/divinylbenzene/polydimethylsiloxane (CAR/DVBIPDMS). The optimal injector temperature and desorption time for each fiber were dete1n1ined by experimental design. The samples analyzed were collected in Tedlar bags at a biogas facility and a sewage treatment plant to represent background levels and point-source emissions. The samples were subsequently dried over CaClz and preconcenti·ated bySPME, and the target compounds were analyzed by GC-MS. CARIPDMS induced the lowest level of artifact formation and initially also exhibited the broadest range of linear adsorption kinetics. Anextraction time of 2.5 min gave no matrix effects, despite the complexity of the samples, and the analytes were accurately quantified using extemal calibration curves below odor thresholds.Detection limits ranged from 0.008 (CS2) to 2.5 (H2S) ppbv, and the relative standard deviation was 4-16%.

  • 47.
    Öquist, Mats
    et al.
    Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Sundh, Ingvar
    Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Effects of a transient oxic period on mineralization of organic matter to CH4 and CO2 in anoxic peat incubations1998In: Geomicrobiology Journal, ISSN 0149-0451, E-ISSN 1521-0529, Vol. 15, no 4, 325-333 p.Article in journal (Refereed)
    Abstract [en]

    Rates of organic matter mineralization in peatlands, and hence production of the greenhouse gases CH4 and CO2, are highly dependent on the distribution of oxygen in the peat. Using laboratory incubations of peat, we investigated the sensitivity of the anoxic production of CH4 and CO2 to a transient oxic period of a few weeks’ duration. Production rates during 3 successive anoxic periods were compared with rates in samples incubated in the presence of oxygen during the second period. In surface peat (5–10‐cm depth), with an initially high level of CH4 production, oxic conditions during period 2 did not result in a lower potential CH4 production rate during period 3, although production was delayed 1 week. In permanently anoxic, deep peat (50–55‐cm depth) with a comparatively low initial production of CH4, oxic conditions during period 2 resulted in zero production of CH4 during period 3. Thus, the methanogens in surface peal—but not in deep peat—remained viable after several weeks of oxic conditions. In contrast to CH4 production, the oxic period had a negligible effect on anoxic CO2 production during period 3, in surface as well as deep peat. In both surface and deep peat, CO2 production was several times higher under oxic than under anoxic conditions. However, for the first 2 weeks of oxic conditions, CO2 production in the deep peat was very low. Still, deep peat obviously contained facultative microorganisms that, after a relatively short period, were able to maintain a considerably higher rate of organic matter mineralization under oxic than under anoxic conditions.

  • 48.
    Pers, Charlotta
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Uncertainty and sensitivity analyses of a model of dissolved organic carbon in a lakeManuscript (preprint) (Other academic)
    Abstract [en]

    Uncertainty and sensitivity analyses have been performed on a lake model describing the dissolved organic carbon (DOC) turnover in a humic lake. The DOC model is based on a Lagrangian dispersion model where trajectories of fluid particles, representing DOC containing water parcels, are simulated. Thus the history of the individual parcel influences its present degradation and DOC concentration. Together the parcels describe the DOC concentration of the lake. A Monte Carlo simulation based on a random sampling of DOC input parameters was used for the analyses. The results were studied one day a monthbetween May 1993 and December 1997. The mean DOC concentration (9-13 mg C L"1) has a range of about 2 mg C L-1 and a coefficient of variation (CV) of 2-4%. That is rather large, but still less than the variability of the input parameters. The daily mean degradation variables (bacterial degradation and photooxidation) had larger variability (CV approx. 20%). Different methods were combined to give multiple views of the sensitivity: scatter plots, the chosen parameters in stepwise regression, and the parameters in multiple linear regression with high partial correlation coefficient and/or high standardised coefficient. In addition, both ordinary and rank based multiple linear regression were used. The combined methods show that the mean DOC concentration in the lake is most sensitive to primary production and bacterial degradation rate, while bacterial degradation and photooxidation are most sensitive to bacterialdegradation rate and the attenuation rate of light respectively. Both seasonal and annual variations in sensitivity indices were found for mean DOC concentration revealing a flow dependence of the crucial parameters. Overall, the DOC model would benefit most from a better estimation of bacterial degradation rate, a better model for primary production, and a better determination of DOC concentration of inflow.

  • 49.
    Narasimha Reddy, Vaka
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
    Comparison and Optimization of Insonation Strategies for Contrast Enhanced Ultrasound Imaging2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Evolution of vulnerable carotid plaques are crucial reason for cerebral ischemic strokes and identifying them in the early stage can become very important in avoiding the risk of stroke. In order to improve the identification and quantification accuracy of infancy plaques better visualization techniques are needed. Improving the visualization and quantification of neovascularization in carotid plaque using contrast enhanced ultrasound imaging still remains a challenging task. In this thesis work, three optimization techniques are proposed, which showed an improvement in the sensitivity of contrast agents when compared to the conventional clinical settings and insonation strategies. They are as follows:1) Insonation at harmonic specific (2nd harmonic) resonance frequency instead of resonance frequency based on maximum energy absorption provides enhanced nonlinear contribution.2) At high frequency ultrasound imaging, shorter pulse length will provide improved harmonic signal content when compared to longer pulse lengths. Applying this concept to multi- pulse sequencing (Pulse Inversion and Cadence contrast pulse sequencing) resulted in increased magnitude of the remaining harmonic signal after pulse summations.3) Peak negative pressure optimization of Pulse Inversion and Cadence contrast pulse sequencing was showed to further enhance the nonlinear content of the backscattered signal from contrast microbubbles without increasing the safety limits, defined by the mechanical index.The results presented in this thesis are based on computational modeling (Bubblesim software) and as a future continuation we plan to verify the simulation results with vitro studies.

  • 50.
    Kärnhall, Johan
    Linköping University, Department of Physics, Chemistry and Biology.
    New SPR based assays for plasma protein titer determination2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Reliable analytical tools are important for time efficient and economical process development, production and batch release of pharmaceuticals. Therapeutics recovered from human plasma, called plasma protein products, involve a large pharmaceutical industry of plasma fractionation. In plasma fractionation of human immunoglobulin G (hIgG) and albumin (HSA) recommended analysis techniques are regulated by the European Pharmacopoeia and are including total protein concentration assays and zone electrophoresis for protein composition and purity. These techniques are robust, but more efficient techniques with higher resolution, specificity and less hands-on time are available.

    Surface plasmon resonance is an optical method to study biomolecular interactions label-free in real time. This technology was used in this master thesis to set up assays using Biacore systems for quantification of HSA and hIgG from all steps of chromatographic plasma fractionation as a tool for process development and in-process control. The analyses have simplified mass balance calculations to a high extent as they imply specific detection of the proteins compared with using total protein detection. The assays have a low hands-on time and are very simple to perform and the use of one master calibration curve during a full week decreases analysis time to a minimum. Quick, in-process control quantification of one sample is easily obtained within <10 minutes. For final QC of hIgG or for process development, an assay to quantify the distribution of the IgG subclasses (1-4) was set up on Biacore and showed significantly lower hands-on time compared with a commercial ELISA.

    All assays showed reliable quantification and identification performed in unattended runs with high precision, accuracy and sensitivity.

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