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  • 1.
    Warth, Benedikt
    Linköping University, The Department of Physics, Chemistry and Biology.
    Design and Application of Software Sensors in Batch and Fed-batch Cultivations during Recombinant Protein Expression in Escherichia coli2008Independent thesis Advanced level (degree of Master), 20 points / 30 hpStudent thesis
    Abstract [en]

    Software sensors are a potent tool to improve biotechnological real time process monitoring and control. In the current project, algorithms for six partly novel, software sensors were established and tested in a microbial reactor system. Eight batch and two fed-batch runs were carried out with a recombinant Escherichia coli to investigate the suitability of the different software sensor models in diverse cultivation stages. Special respect was given to effects on the sensors after recombinant protein expression was initiated by addition of an inducer molecule. It was an objective to figure out influences of excessive recombinant protein expression on the software sensor signals.

    Two of the developed algorithms calculated the biomass on-line and estimated furthermore, the specific growth rate by integration of the biomass changes with the time. The principle of the first was the application of a near infrared probe to obtain on-line readings of the optical density. The other algorithm was founded on the titration of ammonia as only available nitrogen source. The other two sensors analyzed for the specific consumption of glucose and the specific production of acetate and are predicted on an in-line HPLC system.

    The results showed that all software sensors worked as expected and are rather powerful to estimate important state parameters in real time. In some stages, restrictions may occur due to different limitation affects in the models or the physiology of the culture. However, the results were very convincing and suggested the development of further and more advanced software sensor models in the future.

  • 2.
    Zaharans, Eriks
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Indoor robot localization and collaboration2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to create an indoor rescue scenario with multiple self-localizing robots that are able to collaborate for a victim search. Victims are represented by RFID tags and detecting them combined with an accurate enough location data is considered as a successful finding. This setup is created for use in a laboratory assignment at Linköping University.

    We consider the indoor localization problem by trying to use as few sensors as possible and implement three indoor localization methods - odometry based, passive RFID based, and our approach by fusing both sensor data with particle filter.The Results show that particle filter based localization performs the best in comparison to the two other implemented methods and satisfies the accuracy requirements stated for the scenario.

    The victim search problem is solved by an ant mobility (pheromone-based) approach which integrates our localization method and provides a collaborative navigation through the rescue area. The purpose of the pheromone mobility approach is to achieve a high coverage with an acceptable resource consumption.Experiments show that area is covered with approximately 30-40% overhead in traveled distance comparing to an optimal path.

  • 3.
    Hanson, Maryam
    Linköping University, Department of Electrical Engineering, Integrated Circuits and Systems.
    Study on Smart Dust Networks2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis work is done for the department of Electronic System at The Institute of Technology at Linköping University (Linköpings Tekniska Högskolan). Study's focus is to design and implement a protocol for smart dust networks to improve the energy consumption algorithm for this kind of network.

    Smart dust networks are in category of distributed sensor networks and power consumption is one of the key concerns for this type of network. This work shows that by focusing on improving the algorithmic behavior of power consumption in every network element (so called as mote), we can save a considerable amount of power for the whole network.

    Suggested algorithm is examined using Erlang for one mote object and the whole idea has put into test for a small network using SystemC.

  • 4.
    Holm, Rasmus
    Linköping University, Department of Computer and Information Science, Software and Systems.
    Energy-Efficient Mobile Communication with Cached Signal Maps2016Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Data communication over cellular networks is expensive for the mobile device in terms of energy, especially when the received signal strength (RSS) is low. The mobile device needs to amplify its transmission power to compensate for noise leading to an increased energy consumption. This thesis focuses on developing a RSS map for the third generation cellular technology (3G) which can be stored locally at the mobile device, and can be used for avoiding expensive communication in low RSS areas.

    The proposed signal map is created by crowdsourced information collected from several mobile devices. An application is used to collect data in the mobile device of the user and the application periodically sends the information back to the server which computes the total signal map.

    The signal map is composed of three levels of information: RSS information, data rate tests and estimated energy levels. The energy level categorizes the energy consumption of an area into "High", "Medium" or "Low" based on the RSS, data rate test information and an energy model developed from physical power measurements. The coarse categorization provides an estimation of the energy consumption at each location. It is evaluated by collecting data traces on a smartphone at different locations and comparing the measured energy consumption at each location to the energy level categories of the map.

    The RSS prediction is preliminarily evaluated by collecting new data along a path and comparing how well it correlates to the signal map. The evaluation in this thesis shows that with the current collected data there are not enough observations in the map to properly estimate the RSS. However, we believe that with more observations a more accurate evaluation could be done.

  • 5.
    Eneroth, Erik
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Controller Design Enabling Automated and Fuel-Efficient Driving Strategies for Heavy Duty Vehicles in Urban Environments2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The automative industry drives the development towards more autonomous vehicles, this because of both safety and energy conservation reasons. This thesis focuses on solutions to lower the fuel consumption for heavy duty vehicles, which is more and more requested. Both due to increasing fuel costs and to greater environmental awareness. Through extensive simulations with a vehicle model, developed at and provided by Scania CV AB, different driving strategies are evaluated and analysed. This determined how to achieve a low fuel consumption when driving heavy vehicle in an urban environment. The simulations shows that the fuel consumption can be lowered by coasting the vehicle when deceleration and thus minimize the use of the brakes. One should also when possible, select a higher gear to lower the fuel consumption due to engine friction. These strategies are used to develop a controller which lowers the fuel consumption without increasing the trip time for the vehicle. The controller is able to alter the velocity of the vehicle within a reference window which results in both a lower fuel consumption and a shorter trip time for the driving cycle used.

  • 6.
    Ruales Falconi, Alejandra
    Linköping University, The Tema Institute, Tema Environmental Change.
    Cultural paradigm shifts in socio-technical transitions towards sustainable cities: A case study of the transportation system of São Paulo2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Transportation is a key component of the urban realm due to its high fossil fuel consumption, GHG emissions and pollution generation (among other negative externalities) that have been aggravated by an individual motor vehicle-driven society. In order to achieve a balanced urban growth for the future, the transportation paradigm requires a complete shift that will depend upon a change on people’s behaviors and perceptions about mobility. Being the biggest, most populous city of Brazil and the western hemisphere, as well as the financial motor behind the country’s economy, São Paulo currently faces a very serious transportation problem: an extremely high car per capita ratio in conjunction with a deficient public transport network. Furthermore, socioeconomic disparities exert an additional pressure to this dilemma, limiting the access to mobility and deeply embedding the car from a cultural standpoint. Given its prominence, São Paulo is the ideal city to evaluate how specific cultural and socio- spatial niches can steer a cultural paradigm shift that could ultimately trigger a socio-technical transition towards sustainability. In this case study, the role of policies, technology, and infrastructure as policymaking instruments are analyzed in the context of urban spaces in emergent nations, where political and economic structures are strong social determinants. Moreover, this study has shown how these instruments could not only produce a new set of mobility practices (or a new transportation culture) but also the creation of an equitable and thriving urban environment. 

  • 7.
    Mattsson, Angelina
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Milicevic, Adriana
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Hushållens konsumtionsbeteende- En ekonometrisk studie om makrovariablers påverkan på hushållenskonsumtion i Sverige2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The household’s consumption represents two thirds of GDP- growth and can therefor be seenas the engine of the Swedish economy. Changes in the consumption are important to analyzesince consumption is such a big part of the GDP. The purpose of our thesis is to examine theSwedish consumption behavior and analyze whether changes in the interest rate and othermacroeconomic variables affect the households consumption. The macroeconomic variablesthat will be used in our thesis are: the household’s disposable income, interest rate, stockmarketindex and property price index. In order to describe what affects consumption we willbe using some of the most well-known consumption theories such as: Keynes consumptiontheory, Life-cycle hypothesis and Permanent income hypothesis.

    We have done an econometric study where we have examined if there is a long-termrelationship between our chosen variables but also the relationship between the householdsconsumption and the chosen macroeconomic variables. The result of the econometric studyproves that our estimates are in accordance with the theories. However we do believe that thehousehold’s prerequisites have an impact for which theory they identify with. Our estimatesshow that changes in the macroeconomic variables have an important meaning for thehousehold’s consumption and also that changes in the interest rate can affect household’sconsumption.

  • 8.
    Hasan, Mustafa
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Nguyen, Felix
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Inflation och den Marginella konsumtionsbenägenheten2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This essay is an econometric study that aims to empirically estimate the relationship between inflation and marginal propensity to consume in Sweden by Error Correction Model (ECM). Two models are developed using the Error Correction Model (ECM) with explanatory variables such as inflation, real interest rates, disposable income, unemployment, and financial assets. We the focus on the relationship between inflation and marginal propensity to consume (MPC). We estimate short and long term dynamic changes in consumption the parameters by ECM models. The theoretical framework of this paper is the Keynesian consumption theory and the Neo-classical consumption theory. We draw conclusions about the relationship between those factors. The results show that there is a statistically significant relationship between inflation and marginal propensity to consume. In the short term, inflation has a positive correlation on the marginal propensity to consume, which means that willingness to consume in the present increases, in order to not lose purchasing power in the inflation increase. In the long term the relationship is negative for the reason that consumers are maximizing utility and distribute their consumption over time in order to consume at the same level for several periods. We find short-term inflation causes 80 percent increase in the MPC; all else being equal. In the long run, over the two periods, inflation causes 24 percent increase initially and then 27 percent decline in the MPC.

  • 9.
    Johansson, Niklas
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Efficient Simulation of the Deutsch-Jozsa Algorithm2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    We provide a framework wherein one can simulate the Deutsch-Jozsa quantum algorithm on a regular computer within polynomial time, and with linear memory consumption. Under certain reasonable assumptions the simulation solves the problem with a bounded error of probability with only one function evaluation, which is comparable with the efficiency of the quantum algorithm. The provided framework lies within a slight extension of the toy model purposed by Robert W. Spekkens Phys. Rev. A 75 (2007), and consists of transformations that are reminiscent of transformations in quantum mechanics.

  • 10.
    Lundmark, linda
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Definitionen och tolkningen av miljöproblemen och möjliga lösningar: En studie kring Svenska miljöorganisationers argument och perspektiv2015Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    In this study, four different Swedish environmental organizations are examined and compared in order to highlight how they view theenvironmental problems and possible solutions. People from the environmental organizations Naturskyddsföreningen, Klimataktion, Fores andHela Sverige ska leva were interviewed. Additional information was gathered from the various environmental organizations' websites andcatalogs. To get an in-depth discussion and to relate the analyzed material to a larger theoretical context, the arguments of the environmentalorganizations have been analyzed in relation to different environmental discourses. Two relevant theoretical frameworks for this study is Hajersdiscursive theory, which relate to environmental problems and environmental conflicts, and Swyngedouws view of how today's symbolization of"Nature" affect and limit environmental policy. The result shows that the various environmental organizations have a different approach toenvironmental problems and possible solutions. Fores perspective can be related to the ecological modernization discourse, where theenvironmental problem is seen as something that could be dealt with within the current socio-economic frames with a continued economicgrowth. Naturskyddsföreningen do not criticize economic growth, but they believe that the economic systems should be driven in a moreenvironmentally conscious direction. Their perspective can be related to the ecological reconsideration discourse (den ekologiska omprövningensdiskurs). Both Klimataktions and Hela Sverige ska levas approach to environmental problems can be related to the system criticism discourse(Systemkritikens diskurs), where market-based solutions and technological developments are not considered to be enough to solve environmentalproblems. Instead we need to extensively change our way of life with reduced consumption and energy use.

  • 11.
    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.

  • 12.
    Andersson, Simon
    et al.
    Linköping University, The Tema Institute. Linköping University, Faculty of Arts and Sciences.
    Rundström, Robin
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Kommunikation av ekologiskt livsmedel: En intervju- och textanalysstudie av hur ekologiskt livsmedel kommuniceras mot konsumenter2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study focuses on the rhetorical rendering of organic foods, within the research area of environmental communication and ecological theories. The aim is to analyse which renderings are connected to the concept organic foods. Further on Swedish authorities and organisations views on organic foods are examined, in comparison to the grocery retailer’s rhetorical rendering of organic foods. The methodology is based on two methods of data collection. Qualitative research interviews have been conducted with the following authorities: the Swedish Food Agency, the Swedish Consumer Agency and the Swedish Board of Agriculture. Interviews were also conducted with the organisations KRAV and the Swedish Society for Nature Conservation. The interviews were conducted with the intention of making visible the underlying rendering of the concept of organic foods. A textual and metaphor analyses of ICA, Coop and Axfood’s combined communication of organic foods were performed. The aim with these analyses is to examine the grocery retailer’s rhetorical rendering of the concept. The study highlights that there are two main attitudes towards the rendering of organic foods among the actors. Additionally this study clarifies that the authorities, organisations and grocery retailer’s use of the concept differ. Partly the authorities rendering of organics are mainly focused around environmental benefits. While the grocery retailers rendering of organic foods is based on metaphors and idyllic nature values. The study also shows that organic labels is part of green consumerism and thereby legitimize consumption as a solution of environmental and social problems. 

  • 13.
    Ahmed, Uday
    et al.
    Linköping University, Department of Management and Engineering, Manufacturing Engineering. Linköping University, Faculty of Science & Engineering.
    Ayo, Priscilla
    Linköping University, Department of Management and Engineering, Manufacturing Engineering. Linköping University, Faculty of Arts and Sciences.
    Developing Common Questions about Integrated Product Service Engineering (IPSE), Ecodesign and Engineering Education2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the recent years, more and more manufacturing firms recognize the benefit of providing products together with related services with an aim to gain higher profits as compared to supplying products without additional services. On the other hand, the competition in the global markets has been increased dramatically through increased sales of services in order to gain additional value for their products. In addition, several environmental challenges such as climate change, pollution, global warming impact, greenhouse gases emissions have played a vital role by influencing on the production protocols and trend of the companies. These challenges forced manufacturing countries to take into consideration environmentally conscious approach to their design thinking and industrial production processes. As a result, it became an important drive for manufacturing industries to shift from traditional product-oriented to service-oriented business models that has been witnessed during the last few years.

     

    The objective of this study research is to develop common questions that capture fundamental and common issues about Integrated Product Service Engineering (IPSE), Design for Environment (DFE) and Engineering education are effectives for industries to check and develop their knowledge, because the Engineering education plays a necessary role in associating socio-ethical knowledge with scientific and technological advances. The strategy taken to conduct this thesis task was first to study and understand the concept of Product Service System (PSS), IPSE, and Ecodesign as well as Engineering Education. Informative knowledge on these concepts were collected by reviewing several related journal articles, CIRP IPS2 conference proceedings.

     

    In this thesis the concepts of PSS, IPSE, DFE and Engineering Education discussed to develop the key common questions and issues to address the environmental, economic and social problems. Since PSS aims to reduce consumption through alternative schemes of product use as well as to increase overall resource productivity and dematerialization, but IPSE does not focus on a single factor but incorporates a wide range of factors such as environmental, social and economic issues. Whilst one of the main problems in this research focused on how to develop and strengthen the relationship between the academia and industry, and how this relation can be used to improve the academic performance and scientific research at universities and transfer them to industry.

     

    Sustainability and the life cycle concept have become a main solution for various problems such as a growing world population and a change in the industrial culture to come. As results Ecodesign and environmental considerations, financial aspects, product improvement as well as the commercial aspects were discussed in this project by understanding the previous concepts. The university considered as an important base of cultivating the talents, basic of inputs business organizations which help them to develop and improve their level of performance and quality of their products and services, and enhance its competitive position in the market. Changes in organized science further encouraged university interests in expanding technology transfer, because the scientific disciplines play an important role in influencing the type of interactions with industry as well as the University and Industry collaboration became the basic method of solving the problems to achieve (environmental, economic and social) sustainability.

  • 14.
    Szilassy, Martin
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Örn, Daniel
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Low Energy GPS Positioning: A device-server approach2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    GPS is widely used for localization and tracking, however traditional GPS receivers consume too much energy for many applications. This thesis implements and evaluates the performance of a low energy GPS solution, including a working hardware prototype, that reduces energy consumption significantly. The prototype operates for 2 years on a coin cell battery, sampling every minute. The corresponding time for a traditional receiver is 2 days. The main difference is that a traditional receiver requires 30 seconds of data to estimate a position; this solution only requires 2 milliseconds of data, a reduction of a factor 15 000. The solution consists of a portable device, sampling the GPS signal, and server software that utilizes Doppler navigation and Coarse Time Navigation to estimate positions. The median positioning error is at most 38 meters in our tests. We expect that this solution will enable positioning for billions of devices in the near future.

  • 15.
    Qiu, Junting
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, Faculty of Science & Engineering.
    Modeling, Simulation and Control of Long and Short Route EGR in SI Engines2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Modern engines are faced with increasingly stringent requirements for reduced fuel consumptionand lower emissions. A technique which can partly be used to reduce emissionsof nitrogen oxides is recirculation of combusted gases (Exhaust Gas Recirculation, EGR). Ingasoline engines, it also has the advantage that it can save fuel by reducing pumping losses.To large mixture of EGR in the air to the cylinders will however affect the combustion stabilitynegatively. To investigate EGR rate and dynamics with respect to different actuatorinputs, the thesis develops an engine model that includes EGR. The model focus on the airflow in the engine and extends an existing mean value engine model. Two types of EGRsystemare investigated. They are short-route EGR which is implemented between intakemanifold and exhaust manifold and long-route EGR which is implemented between compressorand turbine. The work provides a simulation study that compares both stationaryand transient properties of the two EGR-systems, such as fuel consumption, maximum EGR,and rise time with respect to different actuators.

  • 16.
    Haider, Daniyal
    Linköping University, Department of Electrical Engineering, Integrated Circuits and Systems. Linköping University, Faculty of Science & Engineering.
    On-Chip Phase Measurement Design Study in 65nm CMOS Technology2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Jitter is generally defined as a time deviation of the clock waveform from its desired position. The deviation which occurs can be on the leading or lagging side and it can be bounded (deterministic) or unbounded (random). Jitter is a critical specification in the digital system design. There are various techniques to measure the jitter. The straightforward approach is based on spectrum analyzer or oscilloscope measurements. In this thesis an on-chip jitter measurement technique is investigated and the respective circuit is designed using 65 nm CMOS technology. The work presents the high level model and transistor level model, both implemented using Cadence software. Based on the Vernier concept the circuit is composed of an edge detector, two oscillators, and a phase detector followed by a binary counter, which provides the measurement result. The designed circuit attains resolution of 10ps and can operate in the range of 100 - 500 MHz Compared to other measurement techniques this design features low power consumption and low chip area overhead that is essential for built-in self-test (BIST) applications.

  • 17.
    Colliander Rundberg, Julia Adrianne Martine
    Linköping University, Department of Management and Engineering, Carl Malmsten - furniture studies. Linköping University, Faculty of Science & Engineering.
    Estetik i det kommersiella rummet2015Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    This is a project revolving around the commercial room such as fashion stores with its focus on shop fittings and their way to present products in boutiques like installations. Where fashion and interior blend together, putting layer on layer combining different aesthetic expressions. A space where architecture, interior, furniture, fashion and body meet. An environment depicting beauty and aesthetics that concern intimacy, desire and sensuousness. How do one create commercial spaces that seduce, spaces that evoke desires and cravings?

     

    To find a deeper and wider understanding regarding this subject I wanted to look backwards in history to see how these environments came to be and what counts as the start of our consumption driven society that we live in today. The project resulted in a prototype of a design idé, a piece of furniture regarding storage and the display of clothing, accessories and other fashion related products. With it I wanted to explore certain elements and the way to present and elevate products. I looked at furniture that work as props/scenography which purpose is to enhance and market/sell other products. The furniture has its own tone and is charged with a value regarding quality.

    A few weeks into the project I decided to incorporate the company & Other Stories as a part of my project and target.

  • 18.
    Danielsson, William
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Waldmann, Sebastian
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Avoiding Unnecessary 3G Data Transmission Through Mobile Sensors2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In recent years, instant messaging (IM) has started to replace short message service (SMS) in communication. IM offers more functionality but there is a great downside. IM demands more power and drains the mobile device battery faster. This paper shows the energy consumption of  IM when the user is not using the application and how the consumption  can be reduced by enabling mobile sensors and sending fewer packets by the application. We began by investigating the various sensors that are supported by mobile devices. With the retrieved vendor information, we evaluated the different sensors and chose two sensors, light sensor and proximity sensor in order to study their use for reduction of energy in  an instant messaging scenario. These two sensors can together estimate if the mobile device is placed in the pocket of the user. The development of a simple IM application was completed and sensors were used to create an extension to the application. The extension would lengthen the interval between the updates of the automatic update function when the mobile was inactive, reducing the energy consumption.

    Two types of tests were performed. The first test evaluated if the extension would correctly deduce that the mobile device was placed inside a pocket. The mobile device with the pocket-aware application was used in different common situations and the tests showed that the extension made a correct computation in seven of nine situations. The faulty situations were when the mobile device is placed with the screen faced down to a surface. The second test compared the energy consumed by a pocket-aware application compared to a mobile device without our extension. Based on the results that we retrieved, we estimated that during a one minute period the pocket-aware application with an update interval of ten seconds could save on average 12% and could save on average 62% when the update interval was increased to fifteen seconds.

  • 19.
    Andersson, Isak
    et al.
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Karlsson, Melki
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Body Coupled Communication: Ändring av prototypkort2014Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Communication using the human body as a transmission medium, the capacitive coupling between the skin and sensor, has been an active research area for PAN (Personal Area Network) since Thomas Guthrie Zimmerman introduced the technique in 1995. The reason for this is to examine the benefits and uses of a communication method that does not emit RF signals and thus reduce the risk of unauthorized interception.

    This report describes a thesis that examines the possibility of elimination of USB to UART converter on Microchip BodyCom through software USB-stack and combine this with Body Coupled Communication functionality in a single microcontroller. Furthermore, studies on if the application code in Body Coupled Communication transmitters can be modified to extend functionality.

    It was given in the conditions that microcontrollers from Microchip should be used, furthermore, low price and low power consumption were important, especially for the transmitter. The method for achieving this has been the use of Microchip BodyCom development kit with USB Microchip low pin count development kit and Microchip USB firmware framework.

    The result was that the USB- to UART-converter could be integrated with Microchip BodyCom, using software USB-stack and a modified program code for BodyCom in a single microcontroller.

    Only your imagination sets the limits for Body Coupled Communication can be used for. For example, it would be possible to exchange electronic business cards by a handshake or open a locked door only by using the handle.

  • 20.
    Polis, Rihards
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology. Riga Technical University.
    EnergyBox: Tool improvement and GUI2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    EnergyBox is a parametrised estimation tool that uses packet traces as input to simulate the energy consumption of communication in mobile devices. This tool models the transmission behaviour of a smart phone by analysing a recorded packet trace from the device. The purpose of the thesis is to reimplement the original EnergyBox energy consumption modelling tool. The project aims to develop support for a graphical user interface (GUI) and a code base that is easier to modify and maintain.

    The motivation for the reimplementation of the tool is to simplify its usage and to structure the code so that new features can be added. The existing features such as the calculation of total power consumed by the packet trace and the modelling of a device's energy states are reimplemented and new features are developed. Among the new features, a GUI is added to simplify the usage of the application features such as the detection of the recording device's IP address and the ability to alter the configuration parameters used as input to the energy model.

    The application is written with a GUI and modularity in mind. This is achieved using Java's proprietary new GUI framework - JavaFX, which supports built-in chart and graph GUI elements, that can be easily integrated and supported. The energy modelling engines follow the semantics of the original implementation and the evaluation shows that the new implementation's results are identical to the original tool in 94.94% of the tested cases.

  • 21.
    Rannamaa, Jonas
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    En kristisk studie av metoder för skattningar av CO2 från vägtrafik med diesel som drivmedel.2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There is now no doubt about that it is humans, and our usage of fossil fuels, that contributes to the global warming. Accurate methods of measuring greenhouse gases are vital for future decision making. Road traffic is one of the major sources for greenhouse gases and it is increasing in volume. This study focus on different methods, used to estimate carbon dioxide emissions from road traffic by first estimating the quantity of diesel, from a critical point of view. For that purpose an alternative method used to estimate diesel consumption from road traffic in Sweden is created. The results show differences between methods estimates, some of them in contradiction to each other. The study shows that the results from the model HBEFA 3.1 covariate with both sources of statistics on delivered diesel in Sweden but show lower volumes. The alternative methods created in this study can explain the decrease of diesel consumption in the year 2008-2009 but can’t explain the decrease in the years 1999-2000 and 2011-2012. More studies on differences between the results in the National inventory report Sweden and statistical information on deliveries of diesel, and what is causing them, are needed.

  • 22.
    Wiréhn, Lotten
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, Faculty of Arts and Sciences.
    Climate Suitable Energy Crops and Biomass Energy Potentials: Assessment of the Current and Future Prospects in Estonia2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Development of biomass energy plantations is one approach to mitigate and adapt to climate change and the energy challenges related to it; however, climate change will affect the climate conditions and in turn the selection of crops and trees suitable for renewable energy sources. In Estonia, electricity is mainly based on oil shale but since their integration in the European Union they are required to increase the share of energy from renewable sources. In this study, the possible changes of suitable species are assessed by examining the current and the future prospects and potentials with biomass energy derived from energy plantations in Estonia, taking climate change into consideration. The biomass energy potentials for the species that are climate suitable in current and future time are manually estimated, using a case study approach when determining the yields. The study result suggests that biomass energy from crops and trees have great development possibilities and that climate is not a key limitation for the selection of suitable species; in addition, the energy crops and trees appear to suit the future climate conditions better than the current. The results indicate that the established national target of 25% of energy from renewable sources in gross final consumption of energy by 2020 could be achieved to a large extent by putting energy plantations into practice.

  • 23.
    Knip, Mikael
    et al.
    University of Helsinki, Helsinki, Finland.
    Åkerblom, Hans K
    University of Helsinki, Helsinki, Finland.
    Becker, Dorothy
    University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
    Dosch, Hans-Michael
    University of Toronto, Toronto, Ontario, Canada.
    Dupre, John
    University of Western Ontario, London, Canada.
    Fraser, William
    University of Montréal, Montréal, Québec, Canada.
    Howard, Neville
    Children’s Hospital of Westmead, Sydney, Australia.
    Ilonen, Jorma
    University of Turku, Turku, Finland.
    Krischer, Jeffrey P
    University of South Florida, Tampa, USA.
    Kordonouri, Olga
    Kinder- und Jugendkrankenhaus AUF DER BULT, Hannover, Germany.
    Lawson, Margaret L
    Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada .
    Palmer, Jerry P
    University of Washington, Seattle, USA.
    Savilahti, Erkki
    University of Helsinki, Helsinki, Finland.
    Vaarala, Outi
    National Institute for Health and Welfare, Helsinki, Finland.
    Virtanen, Suvi M
    National Institute for Health and Welfare, Helsinki, Finland.
    Hydrolyzed infant formula and early β-cell autoimmunity: a randomized clinical trial.2014In: Journal of the American Medical Association (JAMA), ISSN 0098-7484, E-ISSN 1538-3598, Vol. 311, no 22, 2279-2287 p.Article in journal (Refereed)
    Abstract [en]

    IMPORTANCE: The disease process leading to clinical type 1 diabetes often starts during the first years of life. Early exposure to complex dietary proteins may increase the risk of β-cell autoimmunity in children at genetic risk for type 1 diabetes. Extensively hydrolyzed formulas do not contain intact proteins.

    OBJECTIVE: To test the hypothesis that weaning to an extensively hydrolyzed formula decreases the cumulative incidence of diabetes-associated autoantibodies in young children.

    DESIGN, SETTING, AND PARTICIPANTS: A double-blind randomized clinical trial of 2159 infants with HLA-conferred disease susceptibility and a first-degree relative with type 1 diabetes recruited from May 2002 to January 2007 in 78 study centers in 15 countries; 1078 were randomized to be weaned to the extensively hydrolyzed casein formula and 1081 were randomized to be weaned to a conventional cows' milk-based formula. The participants were observed to April 16, 2013.

    INTERVENTIONS: The participants received either a casein hydrolysate or a conventional cows' milk formula supplemented with 20% of the casein hydrolysate.

    MAIN OUTCOMES: AND MEASURES: Primary outcome was positivity for at least 2 diabetes-associated autoantibodies out of 4 analyzed. Autoantibodies to insulin, glutamic acid decarboxylase, and the insulinoma-associated-2 (IA-2) molecule were analyzed using radiobinding assays and islet cell antibodies with immunofluorescence during a median observation period of 7.0 years (mean, 6.3 years).

    RESULTS: The absolute risk of positivity for 2 or more islet autoantibodies was 13.4% among those randomized to the casein hydrolysate formula (n = 139) vs 11.4% among those randomized to the conventional formula (n = 117). The unadjusted hazard ratio for positivity for 2 or more autoantibodies among those randomized to be weaned to the casein hydrolysate was 1.21 (95% CI, 0.94-1.54), compared with those randomized to the conventional formula, while the hazard ratio adjusted for HLA risk, duration of breastfeeding, vitamin D use, study formula duration and consumption, and region was 1.23 (95% CI, 0.96-1.58). There were no clinically significant differences in the rate of reported adverse events between the 2 groups.

    CONCLUSIONS AND RELEVANCE: Among infants at risk for type 1 diabetes, the use of a hydrolyzed formula, when compared with a conventional formula, did not reduce the incidence of diabetes-associated autoantibodies after 7 years. These findings do not support a benefit from hydrolyzed formula. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00179777.

  • 24.
    Avdic, Kenan
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    On-chip Pipelined Parallel Mergesort on the Intel Single-Chip Cloud Computer2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the advent of mass-market consumer multicore processors, the growing trend in the consumer off-the-shelf general purpose processor industry has moved away from increasing clock frequency as the classical approach for achieving higher performance. This is commonly attributed to the well-known problems of power consumption and heat dissipation with high frequencies and voltage.

    This paradigm shift has prompted research into a relatively new field of "many-core" processors, such as the Intel Single-chip Cloud Computer. The SCC is a concept vehicle, an experimental homogenous architecture employing 48 IA32 cores interconnected by a high-speed communication network.

    As similar multiprocessor systems, such as the Cell Broadband Engine, demonstrate a significantly higher aggregate bandwidth in the interconnect network than in memory, we examine the viability of a pipelined approach to sorting on the Intel SCC. By tailoring an algorithm to the architecture, we investigate whether this is also the case with the SCC and whether employing a pipelining technique alleviates the classical memory bottleneck problem or provides any performance benefits.

    For this purpose, we employ and combine different classic algorithms, most significantly, parallel mergesort and samplesort.

  • 25.
    Almquist, Mathias
    et al.
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Almquist, Viktor
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    A study on Android games: 3G energy consumption, CPU-utilization and system calls2015Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The popularity of mobile games has increased drastically during the recent years andmany people use them as their main source of entertainment. Mobile gamescommunicate with other devices over the network which consumes a lot of energy,especially when connected to cellular networks (e.g., 3G). This high energy expensecan feel unjustified to the player since always-on network connectivity is not requiredin order to play most games.Furthermore, the number of malware-infected applications in offical applicationstores has increased significantly in the recent years. These malware-infectedapplications can gain unrestricted access and control of users phones which can be athreat to security. Information about the behaviour characteristics of games can beused to develop or improve systems for detecting malware applications.In this thesis, 20 popular Android games are analysed with a focus on the datacommunication, CPU utilization and system call behaviour. The main subject of thedata communication study is the 3G communication energy consumed by games. Thesystem call study aims at quantifying the number and type of calls used by games.This may be useful in a further study of harmful behaviour by apps.The profiling results presented in this report show that the communication energyvaries drastically among games. Games with a very similar gameplay can consumevery different amounts of energy which indicates that there is room for improvementsin many of the games. Ad-free games consume significantly less energy than gamesthat use in-app advertisements. The results show that improving the advertisementfetching policy could reduce the energy consumption of these games. The majority ofthe games can be played without network connectivity and therefore thecommunication energy consumed could be completely avoided. The thesis alsoshows that games use a wide variety of system calls and that many of the system callsare common among the games.

  • 26.
    Ring, Emma
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Modelling a piezoelectric-driven actuator for active flow control2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Flow control is an area of research of particular interest within automotive and aerospace industries since methods used to affect the fluid flow around vehicles can reduce drag and therefore lower their fuel consumption. One of these methods, which has generated a lot of interest in later years, is called active flow control and uses different types of actuators to impact the surrounding flow.

    In this thesis a model of a piezoelectric actuator for active flow control has been developed using Lumped Element Modelling and equivalent circuits. This approach, together with the chosen software for implementation, Simulink, provides models which are easy to simulate and evaluate.

    The actuator model has been validated using a novel methodology with sub-models with the purpose of reducing computational costs. The actuator is therefore divided into two submodels,one for structural and one for fluid dynamics, which are validated separately. This enables the use of simple yet accurate FEM and CFD models instead of time consuming FSI software which the complete model requires.

    The three implemented models have been validated using cases presented in previous studies and data from CFD-simulations. The results show that the decoupled models can be validated separately and its results can be integrated into the complete model, although further tests with a real actuator is needed.

    In addition to the modelling, a parameter study of the actuator has been performed in order to prepare for prototype design.

  • 27.
    Janzén, Johan
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Evaluation of Energy-Optimizing Scheduling Algorithms for Streaming Computations on Massively Parallel Multicore Architectures2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis describes an environment to evaluate and compare static schedulers for real pipelined streaming applications on massively parallel architectures, such as Intel Single chip Cloud Computer (SCC), Adapteva Epiphany, and Tilera TILE-Gx series. The framework allows performance comparison of schedulers in their execution time, or the energy usage of static schedules with energy models and measurements on real platform.

    This thesis focuses on the implementation of a framework evaluating the energy consumption of such streaming applications on the SCC. The framework can run streaming applications, built as task collections, with static schedules including dynamic frequency scaling. Streams are handled by the framework with FIFO buffers, connected between tasks.

    We evaluate the framework by considering a pipelined mergesort implementation with different static schedules. The runtime is compared with the runtime of a previously published task based optimized mergesort implementation. The results show how much overhead the framework adds on to the streaming application. As a demonstration of the energy measuring capabilities, we schedule and analyze a Fast Fourier Transform application, and discuss the results.

    Future work may include quantitative comparative studies of a range of different static schedulers. This has, to our knowledge, not been done previously.

  • 28.
    Grantz, Helene
    Linköping University, Department of Culture and Communication, National Centre for Outdoor Education (NCU). Linköping University, Department of Behavioural Sciences and Learning.
    Handla med handlingskompetens: en kvasiexperimentell studie kring undervisning om hållbar konsumtion2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med den här studien har varit att undersöka vilka skillnader som kan identifieras rörande elevers handlingskomptens beroende på var och hur undervisningen har bedrivits. Jag har velat ta reda på på vilka sätt valet av undervisningsmetoder och valet av plats för undervisningen kan påverka elevernas utveckling av handlingskompetens. Studien har genomförts med en kvasiexperimentell design, där två klasser i årskurs 8 har arbetat med ett tema kring hållbar konsumtion av kläder. Den ena klassen har haft all undervisning i klassrummet medan den andra klassen vid två tillfällen fått gå till stadens centrum för att göra butiksundersökningar och intervjua butikspersonal. I övrigt har båda klasserna fått likartad undervisning av samma lärare. I slutet av projektet genomfördes semistrukturerade gruppintervjuer med eleverna som analyserades med hjälp av tematisk analys. Resultaten visar att klassen som gjort butiksundersökningar i betydligt högre utsträckning såg just att ställa frågor i butiken som ett sätt att påverka för en hållbarare klädkonsumtion. Att de nämner frågandet som en lösning på problemen med klädproduktion och konsumtion kan kopplas till att de fått möjlighet att pröva detta tillvägagångssätt. Men det innebär dock inte med nödvändighet att eleverna kommer att använda sig av denna påverkansmetod när de själva handlar kläder. Intervjuerna visade också att butiksundersökningarna lyftes av elva av tjugo elever som viktigast för att skapa engagemang för ämnet. Näst viktigast ansåg de vara att se på film. I klassen som hade all undervisning i klassrummet var film det mest dominerande sättet att skapa engagemang.

  • 29.
    Gråd, Erik
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Management and Engineering, Economics.
    Riis, Sonny
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Management and Engineering, Economics.
    Att dela eller inte dela?: Vad som möjliggör respektive förhindrar produktdelningssystem2014Student paper other, 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Product sharing systems is recently starting to become a more common phenomenon. Carpools exist in more than 40 Swedish towns and both Stockholm and Gothenburg have established bicycle sharing systems. Other products for which sharing systems have been established throughout Sweden are clothing and tools. From the point of view of the consumer, product sharing systems is a form of consumption which can be placed somewhere in between renting and privately owning a product, where the consumers usually pay a membership fee or a monthly fee to have access to the products whenever they need them. The concept is relatively new, and there are many products for which product sharing systems do not exist. As a consequence, previous research in the area is scarce, with the exception of car pools. However, some research discussing product sharing systems in general exists, such as the research by Lamberton & Rose and Mont. In this thesis, previous research is further developed by analyzing what enables and hinders product sharing systems, and for what type of products these systems are suitable. A mix between a quantitative and a qualitative method is used, as both interviews with owners of sharing systems and a questionnaire survey with potential consumers are carried out. To analyze the concept, institutional and behavioral economic theory is used as well as traditional microeconomics. Both the interviews and the survey indicate that the general knowledge of product sharing systems is low and that it is hard in general for companies to reach out to new users. For the consumers, one of the biggest problems is the perceived risk of not having access to the products when they are needed. Another conclusion is that products for which variety is desired, such as clothing and books, that are used frequently, are especially suitable for product sharing systems.

  • 30.
    Holmstedt, Anton
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Thomasson, Jesper
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Driver hushållens skulder konsumtionen?: En jämförande studie av Sverige, Norge, Danmark och Finland2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The consumption levels in Sweden, Denmark, Finland and Norway have been rising fo r the last decade. Even after the financial crisis of 2008, consumption levels continued their upward trend, regardless of the recession. The explanation seems to be, at least partly, that households tends to increase their debt ratio in order to continue the same standard of living as before in terms of consumption. It is clear, based of our results, that there is a connection between increased consumption and debt ratio for households. And the consequences of allowing loans to finance a sustained or increasing consumption may ultimately be difficult to manage. This paper compares Sweden, Norway, Finland and Denmark to analyze if it is possible to see differences in how debt has affected the consumption since the millennium until 2012. Three different regression models were specified to analyze the data.

  • 31.
    Nyström, Sofie
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Arts and Sciences.
    Förståelse för visualiserad elförbrukning i publik miljö: En användbarhetsstudie av touchdisplayen Urban Energy2014Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Hur publika displayer skall utformas och anpassas efter sin miljö på bästa sätt är ännu ett outforskat område. I takt med att miljöfrågor blivit än mer aktuella i dagens samhälle har det också etablerats ett behov av att förändra vårt beteende exempelvis i form av energieffektivisering. Syftet med denna uppsats är att undersöka hur en publik touchdisplay för elvisualisering skall utformas för att vara förståelig, intuitiv och säker från publik genans. En användarstudie i form av en utvärdering av en interaktiv touchdisplay kallad Urban Energy monterad i Göteborg har gjorts under ledning av Interactive Institute Swedish ICT. Touchdisplayens primära syfte är att uppmärksamma förbipasserande på stadens elförbrukning och uppmuntra till energimedvetenhet.

    I denna studie rekryterades 17 förbipasserande deltagare villiga att testa denna display med hjälp av två uppgifter och en enkät. Resultatet i form av skattningsvärden och observationsprotokoll genererade en tabell med problem och designlösningar. Utifrån användbarhetsstudien kunde slutsatser dras exempelvis angående visuellt interaktionsområde, feedback vid aktiva val, förståelse vid zoomning i tid, termhantering samt kontextens betydelse för publika touchdisplayer. Avslutningsvis ges en diskussion utifrån användbarhetsstudien kring väsentliga aspekter vid utformning av denna typ av display rörande energivisualisering, touchbaserade gränssnitt och social exponering framför publika installationer. 

  • 32.
    Wirell, Viktoria
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Påverkan av förnybar energi på Singapores energisäkerhet2014Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Singapore is one of the most densely populated countries in the world. At the same time the country has an electricity consumption that is among the highest in the world in relation to the population. They have no indigenous energy resources and are therefore dependent on import of fossil fuels to handle their high electricity consumption. Most of their electricity is generated from natural gas which has been imported in pipelines from Malaysia and Indonesia.

    A consequence of Singapore’s heavy dependence on imported fossil fuels is that they have low energy security. Energy security means that the energy supply should be affordable, reliable and adequate. With its heavy dependence on imported fossil fuels, Singapore is exposed to several energy security risks. These energy security risks could result in detrimental consequences for Singapore.

    The environmental benefits of renewable energy are well known, but how renewable energy can contribute to a better energy security is less known. There are several energy security risks related to the use of fossil fuels and renewable energy can therefore, in the countries that have the right conditions, decrease these risks.

    The purpose of this thesis has been to examine if renewable energy can contribute to a more secure electricity supply in Singapore. To do this, theory regarding Singapore, energy security and different renewable energy sources has been collected. The renewable energy sources that have been examined are wind power, hydropower, geothermal energy, solar power and bioenergy. The theoretical background has then been used to analyze the possibility of using renewable energy sources to improve the energy security in Singapore.   

    The conclusion that can be drawn from this study is that some of the renewable energy sources can contribute to a more secure electricity supply in Singapore. Singapore’s geographical conditions are unfavorable for the use of wind power, hydropower and geothermal energy and these energy sources can therefore not be used to improve the energy security in Singapore. The situation regarding solar power and bioenergy is however different and an increase of the electricity production from these sources can contribute to a more secure electricity supply. 

  • 33.
    Maddula, Ravi
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Near threshold operation of 16-bit adders in 65nm CMOStechnology2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The main objective of the thesis is to implement different architectures of 16-bit adders such as; Ripple CarryAdder (RCA), Manchester Carry Chain Adder (MCCA) and Kogge Stone Adder (KSA), in 65nm CMOS technology and to study their performance in terms of power, operating frequency and speed at near threshold operating regions. The performance of these adders are evaluated and compared with each other and a final conclusion is made as to which adder structure is more suitable for implementation in a 65nmtechnology for low power applications. Several optimisation techniques are performed for the adders to reduce the delay and power consumption. Propagation delay is the most critical or essential parameter to be considered, hence, to minimise the delay of the adder, a technique called sizing and ordering are required for the transistors. The purpose of the thesis is to make a fair comparison among adders over several metrics which include linearity, delay and power.

    Simulation results of MCCA achieved a greater significant performance upon or over RCA and KSA, and proved it is the best suitable adder for low power applications.

  • 34.
    Pathapati, Srinivasa Rao
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    All-Digital ADC Design in 65 nm CMOS Technology2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The design of analog and complex mixed-signal circuits in a deep submicron CMOS process technology is a big challenge. This makes it desirable to shift data converter design towards the digital domain. The advantage of using a fully digital ADC design rather than a traditional analog ADC design is that the circuit is defined by an HDL description and automatically synthesized by tools. It offers low power consumption, low silicon area and a fully optimized gate-level circuit that reduces the design costs, etc. The functioning of an all-digital ADC is based on the time domain signal processing approach, which brings a high time resolution obtained by the use of a nanometer CMOS process. An all-digital ADC design is implemented by using a combination of the digital Voltage-Controlled Oscillator (VCO) and a Time-to-Digital Converter (TDC). The VCO converts the amplitude-domain analog signal to a phase-domain time-based signal. In addition, the VCO works as a time based quantizer. The time-based signal from the VCO output is then processed by the TDC quantizer in order to generate the digital code sequences. The fully digital VCO-based ADC has the advantage of superior time resolution. Moreover, the VCO-based ADC offers a first order noise shaping property of its quantization noise.

    This thesis presents the implementation of a VCO-based ADC in STM 65 nm CMOS process technology using digital tools such as ModelSim simulator, Synopsys Design Compiler and Cadence SOC Encounter. The circuit level simulations have been done in Cadence Virtuoso ADE. A multi-phase VCO and multi-bit quantization architecture has been chosen for this 8-bit ADC. The power consumption of the ADC is approximately 630 μW at 1.0 V power supply and the figure of merit is around 410 fJ per conversion step.

  • 35.
    Karczmarz, Veronika
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology.
    Thermal comfort in young broiler chickens (Gallus gallus domesticus) inferred from metabolic expenses.2014Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The thermoneutral zone (TNZ) curve lies between the ambient temperatures (Ta) where an endothermic animal uses the least amount of energy to maintain a balance between the heat production from the animal’s own metabolism and the heat lost to the environment. If the animal is exposed to Ta’s over the upper critical temperature (UCT), which is the highest temperature that is still in the TNZ, the animals have to use energy to cool down. If they are exposed to temperatures lower than the lower critical temperature (LCT), which is the lowest temperature that is still in the TNZ, the animal have to use energy to warm up. In the present study oxygen consumption was measured at different Ta’s to determine the TNZ in two and three week old broiler chickens (Gallus gallus domesticus). Two different protocols were used and compared, a pseudorandom protocol in which chickens were exposed to seven temperatures in two hour periods for each run and a more typical progressive protocol in which Ta decreased gradually, one or two degrees per hour. The TNZ in two weeks old chickens was between 30.7 ˚C- 36.4 ˚C and between 28.8 ˚C- 32.7 ˚C in the three weeks old chickens. In chickens the TNZ shifts remarkably during the first few weeks of life towards lower temperatures as the animals acquire thermoregulatory competence. The method with a pseudorandom protocol takes more factors, like activity, into consideration than a typical progressive protocol.

  • 36.
    Myklebust, Andreas
    et al.
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Eriksson, Lars
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Dry Clutch Micro-Slip Control and Temperature ConsiderationsManuscript (preprint) (Other academic)
    Abstract [en]

    With an automatic clutch in the powertrain it is possible to micro-slip the clutch. Micro-slip is a continuous small slip in the clutch used to isolate the driveline from the oscillations in the torque produced by a combustion engine. A control structure has been designed for a micro-slip controller. The basic components are a Linear Quadratic (LQ) controller based on a linearized driveline model and an Extended Kalman Filter (EKF) that can compensate the torque request from the LQ controller for the thermal dynamics of the clutch. To remove some stationary errors, integral action has been added to the LQ controller by adding an extra state. An anti-windup scheme is used, and the additional parameters depend on clutch conditions. The reference slip value is set according to a derived formula for the flywheel-speed-oscillation amplitude together with a dynamic safety margin that can increase during transients. Altogether the controller has a simple structure and there should be no technical problems to implement it in a production vehicle. In simulations with transient torque, unknown road grades, and a mass parameter that has been varied by a factor of 2, the controller is able to follow the slip reference without locking up. The simulations are performed on a non-linear driveline model, previously validated with data, that has been augmented with a model for the oscillative torque produced by the engine in order to more accurately describe micro-slip conditions. The torque model is a sinusoidal model and has been fitted to high resolution data. The oscillation amplitude and frequency agree well with the data. The thermal behavior of a clutch with micro slip is analyzed and the EKF should be used for temperature surveillance together with some suggested counter measures although there were no excessive temperatures during simulations of recorded driving missions. However, the simulations show that the fuel consumption increase might be too large for a heavy-duty-truck application if micro-slip control is to be used at all operating conditions. Further analysis of costs versus benefits are required on a vehicle level but the feasibility of a micro-slip control system for a dry clutch truck has been proven.

  • 37.
    Andersson, Tim
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, The Institute of Technology.
    Bluetooth Low Energy and Smartphones for Proximity-Based Automatic Door Locks2014Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Bluetooth Low Energy is becoming increasingly popular in mobile applications due to the possibility of using it for proximity data. Proximity can be estimated by measuring the strength of the Bluetooth signal, and actions can then be performed based on a user's proximity to a certain location or object. One of the most interesting applications of proximity information is automating common tasks; this paper evaluates Bluetooth Low Energy in the context of using smartphones to automatically unlock a door when a user approaches the door. Measurements were performed to determine signal strength reliability, energy consumption and connection latency. The results show that Bluetooth Low Energy is a suitable technology for proximity-based door locks despite the large variance in signal strength.

  • 38.
    Engström, Adam
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Strömsparande arkitektur för inbyggnadslinux2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The objective of this work was to evaluate and implement a number of energy saving functions for a specific embedded system. The functions were then grouped into a number of energy levels with known properties in terms of functionality, energy consumption, and transition time between the levels.

    The embedded system consisted of an AT91 ARM9 processor, GSM/GPRS modem, display, Ethernet and other peripheral units. Some energy saving methods that were considered were suspend to RAM, suspend to disk, frequency scaling, and methods for saving energy in the modem, Ethernet, USB and display backlight. The functions were grouped into levels and an interface was specified for controlling the energy level.

    It proved possible to get known properties within the defined energy levels, even though the paritioning of functions into these levels proved to be sub-optimal in a typical application usage scenario because it was designed for mainly energy consumption, not usage.

    The final result is a number of energy saving functions grouped into levels, which are controllable via an application interface. Each of the levels have a known energy consumption in both loaded and un-loaded mode.

  • 39.
    Ali, Rahman
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Design of Building Blocks in Digital Baseband Transceivers for Body-Coupled Communication2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Advances in communication technologies continue to increase information sharing among the people.~Short-range wireless networking technologies such as Bluetooth or ZigBee, which are mainly used for data transfer over short range, will, however, suffer from network congestion, high power consumption and security issues in the future.

    The body-coupled communication (BCC), a futuristic short-range wireless technology, uses the human body as a transmission medium. In BBC channel, a small electric field is induced onto the human body which enables the propagation of a signal between communication devices that are in the proximity or direct contact with the human body. The direct baseband transmission and simple architecture make BCC an attractive candidate for a future short-range wireless communication technology in particular applications such as body area network.

    The main focus of this thesis is on the design and implementation of digital baseband transmitter and receiver for the body-coupled communication. The physical layer (PHY) implementation of the digital baseband transmitter and receiver is inspired from the IEEE 802.3 Ethernet transmission protocol. The digital design is implemented at RTL level using hardware description language (VHDL). The functionality of the digital baseband transmitter and receiver is demonstrated by developing data transfer application layers.

  • 40.
    Khan, Abbas
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Optimization through Co-Simulation of Antenna, Bandpass Filter and Low-Noise Amplifier at 6-9 GHz2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Ultra-wide band (UWB) 6-9 GHz antenna, band pass filter and low-noise amplifier (LNA) optimization using co-simulation of the RF front-end. At higher frequencies, carefully conducted design methodologies are required for RF front-end parameter optimization, such as power gain and low noise figure with low power consumption.

  • 41.
    Nilsson, Samuel
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Eriksson, Joakim
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Estimating Application Energy Consumption Through Packet Trace Analysis2014Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The advancement of mobile clients and applications makes it possible for people to always stayconnected, sending and receiving data constantly. The nature of the 3G technology widelyused, however, causes a high battery drain in cellular phones and because of that a lot of toolsfor measuring mobile phones energy consumption has been developed. In this report we lookinto the trace-driven tool EnergyBox and find out how we can use it to estimate the energyconsumption of 3G transmissions for an application we’ve developed ourselves. We beginwith identifying the types of traffic our application generates and identify which parts of itmake up our applications background traffic. Different combinations of the identified traffictypes are looked into in order to decide which ones that need to be present in the packet tracesfor an estimation of our applications energy footprint for 3G transmission. Further, answersare sought to how long the time span should be for which the packet traces are collected andhow many of them are needed in order to draw a conclusion about our application’s energyfootprint. We conclude that all traffic types responsible for our application’s backgroundtraffic need to be present in the analyzed packet traces, and data suggests that collectingmore than 10 one minute packet traces does not improve accuracy significantly (less than1%). Without user interaction, our application generates traffic, which transmitted over 3G,drains as much as an average of 930mW, meaning that a Samsung Galaxy S4 battery with acapacity of 9.88Wh would last for a maximum of 10 hours and 30 minutes (excluding otherenergy consuming sources inside the handset).

  • 42.
    Gustavsson, Sofia
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Niklasson, Anna
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Städers arbete med koldioxidneutralitet: En textanalytisk studie om problemframställningar2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As a result of the increasing threats from climate change more cities have started to work with decreasing their climate impact. One example ofthis is to pursue carbon neutrality. This study aims to examine what the problem is represented to be by cities in their work to achieve carbonneutrality. Based on framing and Bacchi’s (1999) analyzing tool about problem representations, as well as previous research on cities and climatechange, the three cities Linköping, Copenhagen and Melbourne have been examined. Documents concerning carbon neutrality in the cities havebeen analyzed by the use of qualitative text analysis. The study shows that energy and waste are two issues that often are highlighted andproblematized by cities while consumption and the behaviour of individuals are excluded from the problem representation.

  • 43.
    Wali, Naveen
    et al.
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Radhakrishnan, Balamurali
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Design of a Time-to-Digital Converter for an All-Digital Phase Locked Loop for the 2-GHz Band2013Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    An all-digital phase locked loop for WiGig systems was implemented. The developedall-digital phase locked loop has a targeted frequency range of 2.1-GHz to2.5-GHz. The all-digital phase locked loop replaces the traditional charge pumpbased analog phase locked loop. The digital nature of the all-digital phase lockedloop system makes it superior to the analog counterpart.There are four main partswhich constitutes the all-digital phase locked loop. The time-to-digital converteris one of the important block in all-digital phase locked loop.

    Several time-to-digital converter architectures were studied and simulated. TheVernier delay based architecture and inverter delay based architecture was designedand evaluated. There architectures provided certain short comings whilethe pseudo-differential time-to-digital converter architecture was chosen, becauseof it’s less occupation of area. Since there exists a relationship between the sizeof the delay cells and it’s time resolution, the pseudo-differential time-to-digitalconverter severed it’s purpose.

    The whole time-to-digital converter system was tested on a 1 V power supply,reference frequency 54-MHz which is also the reference clock Fref , and a feedbackfrequency Fckv 2.1-GHz. The power consumption was found to be around 2.78mW without dynamic clock gating. When the clock gating or bypassing is done,the power consumption is expected to be reduced considerably. The measuredtime-to-digital converter resolution is around 7 ps to 9 ps with a load variation of15 fF. The inherent delay was also found to be 5 ps. The total output noise powerwas found to be -128 dBm.

  • 44.
    Bengtsson, Mikael
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    A clock driver with reduced EMI2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A clock driver that works on the principle of charging and discharging the clock network in a VLSI circuit in two steps is investigated in a few different configurations. The aim of the design is twofold:

    • to reduce the power consumption
    • to reduce the third harmonic of the clock signal, and thereby the EMI (electromagnetic interference) emitted by the clock network.

    The first should be possible to accomplish as the clock interconnect network gets charged by half the voltage during each rising transition, and the second should be possible to accomplish by carefully time the rising and falling transitions, so that the third Fourier coefficient of the resulting wave form cancels.

    The drivers are loaded by eight 16-bit adders. The drivers’ power consumption, and the spectrum of the output signal, are investigated under varying clock frequencies, power supply voltage, and driver architecture. The results are compared to a conventional square wave clock.

    The results are that while the third harmonics of the resulting output sees an improvement in all the investigated cases over the square wave clock, the power savings are, for higher clock frequencies, more than completely canceled by the extra power needed in the logic stage which controls these drivers. On the other hand, the power consumption of the new driver appears to drop below that of the conventional driver when the clock frequency drops below approximately 100MHz.

    A few suggestions for further investigations of new designs and clock wave forms are given.

  • 45.
    Lundström, Fredrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Rondin, Joakim
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    ANSDA - An analytic assesment of its processes2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This is the final report of ANSDA – An analytic assessment of its processes written as a bachelor thesis in the fall of 2013 by students at Linköpings Universitet. It is an analysis of the incident evaluation process used by LFV: ANS-DA. The thesis aimed to find areas where the process could be optimized in regards to time-consumption and efficency in dealing with errors in Air Traffic Control procedure, which are observed when an anomaly in the system occurs.

  • 46.
    Moreno Arocena, Ugaitz
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Energy Consumption Studies for 3G Traffic Consolidation on Android using WiFi and Bluetooth2014Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Mobile phones have evolved from being devices just to make phone calls to become smartphones with added capabilities like surfing the network. Wireless communication has played a very important role in the evolution of smartphones.

    The work in this thesis aims to study the potential to reduce the energy consumption of the 3G communications by using a hybrid architecture. An idea first presented in the paper by Vergara and Nadjm-Tehrani [1]. This architecture consists of a group of nodes that communicate using WiFi or Bluetooth to forward their traffic using one node's 3G interface. In this thesis the named energy sharing scheme is implemented on Android mobile devices and experiments have been performed using a number of realistic traces to assess achievable gains and the energy footprint of the scheme itself.

    Even though communication technologies, screen features, multimedia capabilities, or processing power have been taken to the highest level, phones' batteries have not improved at the same speed. Nowadays battery lifetime has become a major issue with respect to cellular communication.

    With 3G communications Internet connection anytime and anywhere is provided to the terminals but this technology is optimized for peak performance whereas in underutilization it wastes a lot of energy. This makes it a big black hole from power consumption point of view when transmitting small amounts of data.

  • 47.
    Fälton, Emelie
    Linköping University, Department for Studies of Social Change and Culture, Department of History, Tourism and Media. Linköping University, Faculty of Arts and Sciences.
    Food and Sustainable Tourism: A study of authenticity and organic food in a customer supply perspective2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The tourism industry has a large impact on the environment’s health and tourists’ behaviours as well as consumption attitudes have an important role. Tourists’ food decisions and engagements in sustainable food could encourage the tourism operators to improve their environmental burdens. This essay investigates the experience of organic food as a part of the sustainable development within the tourism industry. A dualistic authenticity framework has been applied and a method to measure and analyse perceived authenticity has been drawn from the literature. Questionnaires were handed out to the guests and the staff at two Swedish hotels. The results revealed that there are several dimensions in the meeting between the customers and the operators that arrange food experiences in touristic contexts. There is an interest for the question of organic food as a part of the environmental sustainable development, both relative to the contemporary tourism industry and for the future convention to a more sustainable development in the tourism industry. The results presented that organic food is experienced as a central concept that could be a part of and have an important role for the future sustainable development within the tourism industry. An important part of this is the importance to be aware of the meeting between the customers and the operators. Sweden has a potential to accomplish a more sustainable tourism industry in the future, but more research and educations with focus on the subject needs to be made.

  • 48.
    Zelenenkaya, Ekaterina
    Linköping University, Department of Culture and Communication. Linköping University, Faculty of Arts and Sciences.
    Material Objects as Means of Portraying Female Characters' Personality in the 20th century: As Exemplified in the three Short Stories by J. D. Salinger, V. Woolf and F. Weldon2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The world we live in is full of material objects that serve as signs and thus are an important tool in literary texts. The purpose of the present essay is to illustrate how material objects are used to portray personalities of female characters, their inner world and attitudes, their ways of life and position in society. It is especially interesting in the context of the 20th century in the Western world, when the culture of consumption was gaining momentum and the role of a woman was gradually changing. The short stories analysed in the essay are written in the Western context in the 20th century, which are “A Perfect Day for Bananafish” by J.D. Salinger, “Moments of Being: ‘Slater’s Pins Have no Points’” by V. Woolf and “The Bottom Line and the Sharp End” by F. Weldon. The material objects mentioned in the texts are classified and analysed due to their role and purpose in the short stories.

  • 49.
    Borg, Anna
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Strömer, Petra
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Miljöbedömning av ett flerbostadshus i Hammarby Sjöstad, Stockholm2005Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As a help during design-, construction- and operations phases, there are several tools to use when evaluate residential assessments. This report shows how two methods can be used for multi-residential buildings. The methods are EcoEffect and Green Building Challenge.

    EcoEffect is a Swedish assessment to measure and evaluate environmental loadings from a building during a lifecycle. EcoEffect shows the loadings as a negative effect on human health, ecosystem and impoverish of natural sources.

    Green Building Challenge is an international cooperation started in 1996 with the purpose to develop an environmental assessment structure for buildings. The aim of the tool is an international interface to compare existing buildings.

    The evaluated building is kv. Holmen, placed in Hammarby Sjöstad, Stockholm. The building has nine floors with a garage in the basement. At first floor, there are restaurants and retails. Residual building is for residential occupancies. The assessments show that for some evaluated issues, such as energy and environmental loadings, kv. Holmen has a lower environmental effect compared to standard. Some results are surprisingly low in comparison with the environmental profile for kv. Holmen. One reason to these results might be that the building has not been in use more than one and a half year. The results of the measurements will probably be different in a couple of years when the consumption is stabilized and all residential are occupied. Another reason might be that the profile worked out for kv. Holmen is too ambitious for knowledge and techniques of today.

  • 50.
    Chen, Ting
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Energy-Efficient Resource Allocation in OFDMA Systems2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis, a resource allocation problem in OFDMA is studied for the energy efficiency of wireless network. The objective is to minimize the total energy consumption which includes transmission energy consumption, and circuit energy consumption at both transmitter and receiver with required per user’s rate constraint. For problem solution, a heuristic algorithm with low computational complexity and suboptimal solution is proposed, developed in two steps with an increasing order of complexity. Besides, a bounding scheme based on model linearization of formulated nonlinear system model is also proposed to give lower and upper bounds for both small- and large-scale OFDMA network for further algorithm performance evaluation, while the implemented exhaustive search is only capable to provide the optimal solution for small-scale instance for algorithm performance evaluation. Numerical results show that the proposal heuristic algorithm can achieve near-optimal performance with applicable computational complexity even for large-scale networks, and that the bounds from the bounding scheme are very tight for both small- and large-scale OFDMA networks.

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