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  • 451.
    Tan, He
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Kaliyaperumal, Rajaram
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Benis, Nirupama
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Ontology-driven Construction of Corpus with Frame Semantics Annotations2011Ingår i: poster at The Fourth International Symposium on Languages in Biology and Medicine, 2011Konferensbidrag (Refereegranskat)
  • 452.
    Tan, He
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Kaliyaperumal, Rajaram
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Benis, Nirupama
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Ontology-Driven Construction of Domain Corpus with Frame Semantics Annotations2012Ingår i: Computational linguistics and intelligent text processing, Springer Berlin/Heidelberg, 2012, s. 54-65Konferensbidrag (Refereegranskat)
    Abstract [en]

    Semantic Role Labeling plays a key role in many text mining applications. The development of SRL systems for the biomedical domain is frustrated by the lack of large domain specific corpora that are labeled with semantic roles. In this paper we proposed a method for building corpus that are labeled with semantic roles for the domain of biomedicine. The method is based on the theory of frame semantics, and uses domain knowledge provided by ontologies. By using the method, we have built a corpus for transport events strictly following the domain knowledge provided by GO biological process ontology. We compared one of our frames to a BioFrameNet frame. We also examined the gaps between the semantic classification of the target words in this domain-specific corpus and in FrameNet and PropBank/VerbNet data. The successful corpus construction demonstrates that ontologies, as a formal representation of domain knowledge, can instruct us and ease all the tasks in building this kind of corpus. Furthermore, ontological domain knowledge leads to well-defined semantics exposed on the corpus, which will be very valuable in text mining applications.

  • 453.
    Tan, He
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    A Method for Recommending Ontology Alignment Strategies2007Ingår i: ISWC: International Semantic Web Conference ASWC: Asian Semantic Web Conference The Semantic Web 6th International Semantic Web Conference, 2nd Asian Semantic Web Conference, ISWC 2007 + ASWC 2007, Busan, Korea, November 11-15, 2007. Proceedings / [ed] Karl Aberer, Key-Sun Choi, Natasha Noy, Dean Allemang, Kyung-Il Lee, Lyndon Nixon, Jennifer Golbeck, Peter Mika, Diana Maynard, Riichiro Mizoguchi, Guus Schreiber, Philippe Cudré-Mauroux, Springer Berlin/Heidelberg, 2007, s. 494-507Konferensbidrag (Refereegranskat)
    Abstract [en]

    In different areas ontologies have been developed and many of these ontologies contain overlapping information. Often we would therefore want to be able to use multiple ontologies. To obtain good results, we need to find the relationships between terms in the different ontologies, i.e. we need to align them. Currently, there already exist a number of different alignment strategies. However, it is usually difficult for a user that needs to align two ontologies to decide which of the different available strategies are the most suitable. In this paper we propose a method that provides recommendations on alignment strategies for a given alignment problem. The method is based on the evaluation of the different available alignment strategies on several small selected pieces from the ontologies, and uses the evaluation results to provide recommendations. In the paper we give the basic steps of the method, and then illustrate and discuss the method in the setting of an alignment problem with two well-known biomedical ontologies. We also experiment with different implementations of the steps in the method.

  • 454.
    Tan, He
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Aligning and merging biomedical ontologies2006Ingår i: Seventh Swedish Bioinformatics Workshop for PhD students and PostDocs,2006, 2006, s. 18-18Konferensbidrag (Övrigt vetenskapligt)
  • 455.
    Tan, He
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    SAMBO results for the Ontology Alignment Evaluation Initiative 20072007Ingår i: International Workshop on Ontology Matching,2007, CEURWS , 2007, s. 236-Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article describes a system for ontology alignment, SAMBO, and presents its results for the benchmark and anatomy tasks in the 2007 Ontology Alignment Evaluation Initiative. For the benchmark task we have used a strategy based on string matching as well as the use of a thesaurus, and obtained good results in many cases. For the anatomy task we have used a combination of string matching and the use of domain knowledge. This combination performed well in former evaluations using other anatomy ontologies.

  • 456.
    Tan, He
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Selecting an ontology for biomedical text mining2009Ingår i: 17th Conference on Intelligent Systems for Molecular Biology, 2009Konferensbidrag (Refereegranskat)
  • 457.
    Tan, He
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Selecting an ontology for biomedical text mining2009Ingår i: Workshop on BioNLP, 2009, s. 55-62Konferensbidrag (Refereegranskat)
  • 458.
    Thomas, Kristin
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    Bendtsen, Marcus
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Linderoth, Catharina
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    Karlsson, Nadine
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    Bendtsen, Preben
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Närsjukvården i västra Östergötland, Medicinska specialistkliniken.
    Müssener, Ulrika
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    Short message service (SMS)-based intervention targeting alcohol consumption among university students: study protocol of a randomized controlled trial2017Ingår i: Trials, ISSN 1745-6215, E-ISSN 1745-6215, Vol. 18, artikel-id 156Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Despite significant health risks, heavy drinking of alcohol among university students is a widespread problem; excessive drinking is part of the social norm. A growing number of studies indicate that short message service (SMS)-based interventions are cost-effective, accessible, require limited effort by users, and can enable continuous, real-time, brief support in real-world settings. Although there is emerging evidence for the effect of SMS-based interventions in reducing alcohol consumption, more research is needed. This study aims to test the effectiveness of a newly developed SMS-based intervention targeting excessive alcohol consumption among university and college students in Sweden. Methods: The study is a two-arm randomized controlled trial with an intervention (SMS programme) and a control (treatment as usual) group. Outcome measures will be investigated at baseline and at 3-month follow up. The primary outcome is total weekly alcohol consumption. Secondary outcomes are frequency of heavy episodic drinking, highest estimated blood alcohol concentration and number of negative consequences due to excessive drinking. Discussion: This study contributes knowledge on the effect of automatized SMS support to reduce excessive drinking among students compared with existing support such as Student Health Centres.

  • 459.
    Thomas, Kristin
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    Linderoth, Catharina
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    Bendtsen, Marcus
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Bendtsen, Preben
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Närsjukvården i västra Östergötland, Medicinska specialistkliniken.
    Müssener, Ulrika
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    Text Message-Based Intervention Targeting Alcohol Consumption Among University Students: Findings From a Formative Development Study2016Ingår i: JMIR mhealth and uhealth, E-ISSN 2291-5222, Vol. 4, nr 4, artikel-id e119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Drinking of alcohol among university students is a global phenomenon; heavy episodic drinking is accepted despite several potential negative consequences. There is emerging evidence that short message service (SMS) text messaging interventions are effective to promote behavior change among students. However, it is still unclear how effectiveness can be optimized through intervention design or how user interest and adherence can be maximized. Objective: The objective of this study was to develop an SMS text message-based intervention targeting alcohol drinking among university students using formative research. Methods: A formative research design was used including an iterative revision process based on input from end users and experts. Data were collected via seven focus groups with students and a panel evaluation involving students (n= 15) and experts (n= 5). Student participants were recruited from five universities in Sweden. A semistructured interview guide was used in the focus groups and included questions on alcohol culture, message content, and intervention format. The panel evaluation asked participants to rate to what degree preliminary messages were understandable, usable, and had a good tone on a scale from 1 (very low degree) to 4 (very high degree). Participants could also write their own comments for each message. Qualitative data were analyzed using qualitative descriptive analysis. Quantitative data were analyzed using descriptive statistics. The SMS text messages and the intervention format were revised continuously in parallel with data collection. A behavior change technique (BCT) analysis was conducted on the final version of the program. Results: Overall, students were positive toward the SMS text message intervention. Messages that were neutral, motivated, clear, and tangible engaged students. Students expressed that they preferred short, concise messages and confirmed that a 6-week intervention was an appropriate duration. However, there was limited consensus regarding SMS text message frequency, personalization of messages, and timing. Overall, messages scored high on understanding (mean 3.86, SD 0.43), usability (mean 3.70, SD 0.61), and tone (mean 3.78, SD 0.53). Participants added comments to 67 of 70 messages, including suggestions for change in wording, order of messages, and feedback on why a message was unclear or needed major revision. Comments also included positive feedback that confirmed the value of the messages. Twenty-three BCTs aimed at addressing self-regulatory skills, for example, were identified in the final program. Conclusions: The formative research design was valuable and resulted in significant changes to the intervention. All the original SMS text messages were changed and new messages were added. Overall, the findings showed that students were positive toward receiving support through SMS text message and that neutral, motivated, clear, and tangible messages promoted engagement. However, limited consensus was found on the timing, frequency, and tailoring of messages.

  • 460.
    Tim, Andersson
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Result size calculation for Facebook's GraphQL query language2018Självständigt arbete på grundnivå (högskoleexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [en]

    GraphQL is a query language for web APIs and a service for carrying out server requeststo interact with the data from the API. Research show that even for simple GraphQL queriesboth the size of the response object and the execution times to retrieve these objects may beprohibitively large and that current implementations of the language suffers from this issue.This thesis explores the implementation of an algorithm for calculating the exact size of theresponse object from a GraphQL query, and the performance based evaluation of the implementation. A proof of concept of a server using the implementation of the algorithm and subsequent tests of thecalculation times for particularly problematic queries sent to the server, show that the implementationscales well and could serve as a way to stop these queries from executing.

  • 461.
    Tjärnström, Fredrik
    et al.
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska högskolan.
    Duppils, Mattias
    Linköpings universitet, Institutionen för systemteknik, Elektroniska komponenter. Linköpings universitet, Tekniska högskolan.
    Haslum, Patrik
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska högskolan.
    Byers, David
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Kulups, Gundars
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska högskolan.
    Lawesson, Dan
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska högskolan.
    ENSYM-Project Oriented Studies of spring 98 - team 11999Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The report is description of the ENSYM Project Oriented Studies(POS) of spring 1998. The project goal was to control a toy cararound a not beforehand given track as fast as possible.

  • 462.
    Tran, Huy
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Human resource matching through query augmentation for improving search context2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The objective with the thesis is to research how to match a company's human resources with job assignments received from clients. A common problem is the difficulty for computers to distinguish what semantic context a word is in. This means that for words with multiple interpretations it is hard to determine which meaning is the correct meaning in a given context.

    The proposed solution is to use ontologies to implement a query augmentation that will improve defining the context through users adding suggestions of relevant words. The intuition is that by incrementally adding words, the context narrows, making it easier to search for any consultant matching a specific assignment. The query augmentation will then manifest in a web application created in NodeJS and AngularJS.

    The experiments will then measure, based on \emph{precision}, \emph{recall} and \emph{f-measure}, the performance of the query augmentation.

    The thesis will also look into how to store document-based résumés, .docx file-format, and properly enable querying over the database of résumés. The Apache based frameworks Solr and Lucene, with its inverted indexing and support for HTTP requests, are used in this thesis to solve this problem.

    Looking at the results, the query augmentation was indicated of having somewhat too strict restrictions for which the reason is that it only permits \emph{AND} conditions. With that said, the query augmentation was able to narrow down the search context.

    Future work would include adding additional query conditions and expand the visualization of the query augmentation.

  • 463.
    Törnblom, John
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Improving Quality of Avionics Software Using Mutation Testing2014Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Mutation testing is a powerful fault-based testing technique that makes syntactic changes to a program under test in order to simulate real faults otherwise caused by a programmer. Similar to structural coverage criteria such as statement coverage, mutation testing is used to assess the quality of a test suite. After a syntactic change has been made, the program is referred to as a mutant that either can survive a test suite, or be killed by one. If a mutant is killed, it means that the test suite has detected the syntactic change and reported it as an error, resulting in an increased mutation score. If a mutant survives, it means that the test suite failed to detect the fault and the mutation score is decreased.

    Mutation testing is generally considered the strongest testing technique available in terms of fault detection, but also the most expensive one. However, thanks to recent research and the rapid development of computing hardware, the testing technique is starting to become feasible, motivating the creation of tools utilizing the power of mutation testing.

    Saab AB, the Swedish aircraft manufacturer and stakeholder in this thesis, has experimented with mutation testing in the past, resulting in a tool called BAX that creates textual modifications of the original source code. The initial goal of this thesis is to provide a new tool that is faster than BAX, and that is more systematic in the way mutants are generated.

    LLVM-P86, the main contribution of this thesis, is a compiler and mutation testing framework intended for the programming language Pascal-86. Unlike BAX, LLVM-P86 is able to encode several mutants into a single program, thus reducing the time spent on compiling source code. In the conducted experiments, LLVM-P86 processed mutants significantly faster than BAX, on average by a factor of 13.6.

    Since LLVM-P86 is also a compiler, proper type information is available when mutants are generated. The additional type information allows LLVM-P86 to avoid a significant amount of equivalent mutants, i.e. mutants that behave in the same way as the original program. When mutating relational operators found in approximately 10,000 lines of code, distributed amongst 18 different Pascal-86 modules, LLVM-P86 was able to reduce the total number of living mutants by 25%, or 5.7% of the complete set of mutants.

  • 464.
    Vapen, Anna
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Contributions to Web Authentication for Untrusted Computers2011Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Authentication methods offer varying levels of security. Methods with one-time credentials generated by dedicated hardware tokens can reach a high level of security, whereas password-based authentication methods have a low level of security since passwords can be eavesdropped and stolen by an attacker. Password-based methods are dominant in web authentication since they are both easy to implement and easy to use. Dedicated hardware, on the other hand, is not always available to the user, usually requires additional equipment and may be more complex to use than password-based authentication.

    Different services and applications on the web have different requirements for the security of authentication.  Therefore, it is necessary for designers of authentication solutions to address this need for a range of security levels. Another concern is mobile users authenticating from unknown, and therefore untrusted, computers. This in turn raises issues of availability, since users need secure authentication to be available, regardless of where they authenticate or which computer they use.

    We propose a method for evaluation and design of web authentication solutions that takes into account a number of often overlooked design factors, i.e. availability, usability and economic aspects. Our proposed method uses the concept of security levels from the Electronic Authentication Guideline, provided by NIST.

    We focus on the use of handheld devices, especially mobile phones, as a flexible, multi-purpose (i.e. non-dedicated) hardware device for web authentication. Mobile phones offer unique advantages for secure authentication, as they are small, flexible and portable, and provide multiple data transfer channels. Phone designs, however, vary and the choice of channels and authentication methods will influence the security level of authentication. It is not trivial to maintain a consistent overview of the strengths and weaknesses of the available alternatives. Our evaluation and design method provides this overview and can help developers and users to compare and choose authentication solutions.

  • 465.
    Vapen, Anna
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Web Authentication using Third-Parties in Untrusted Environments2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    With the increasing personalization of the Web, many websites allow users to create their own personal accounts. This has resulted in Web users often having many accounts on different websites, to which they need to authenticate in order to gain access. Unfortunately, there are several security problems connected to the use and re-use of passwords, the most prevalent authentication method currently in use, including eavesdropping and replay attacks.

    Several alternative methods have been proposed to address these shortcomings, including the use of hardware authentication devices. However, these more secure authentication methods are often not adapted for mobile Web users who use different devices in different places and in untrusted environments, such as public Wi-Fi networks, to access their accounts.

    We have designed a method for comparing, evaluating and designing authentication solutions suitable for mobile users and untrusted environments. Our method leverages the fact that mobile users often bring their own cell phones, and also takes into account different levels of security adapted for different services on the Web.

    Another important trend in the authentication landscape is that an increasing number of websites use third-party authentication. This is a solution where users have an account on a single system, the identity provider, and this one account can then be used with multiple other websites. In addition to requiring fewer passwords, these services can also in some cases implement authentication with higher security than passwords can provide.

    How websites select their third-party identity providers has privacy and security implications for end users. To better understand the security and privacy risks with these services, we present a data collection methodology that we have used to identify and capture third-party authentication usage on the Web. We have also characterized the third-party authentication landscape based on our collected data, outlining which types of third-parties are used by which types of sites, and how usage differs across the world. Using a combination of large-scale crawling, longitudinal manual testing, and in-depth login tests, our characterization and analysis has also allowed us to discover interesting structural properties of the landscape, differences in the cross-site relationships, and how the use of third-party authentication is changing over time.

    Finally, we have also outlined what information is shared between websites in third-party authentication, dened risk classes based on shared data, and proled privacy leakage risks associated with websites and their identity providers sharing data with each other. Our ndings show how websites can strengthen the privacy of their users based on how these websites select and combine their third-parties and the data they allow to be shared.

    Delarbeten
    1. Security Levels for Web Authentication using Mobile Phones
    Öppna denna publikation i ny flik eller fönster >>Security Levels for Web Authentication using Mobile Phones
    2011 (Engelska)Ingår i: Privacy and Identity Management for Life / [ed] Simone Fischer-Hübner, Penny Duquenoy, Marit Hansen, Ronald Leenes and Ge Zhang, Boston: Springer , 2011, s. 130-143Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    Mobile phones offer unique advantages for secure authentication: they are small and portable, provide multiple data transfer channels, and are nearly ubiquitous. While phones provide a flexible and capable platform, phone designs vary, and the security level of an authentication solution is influenced by the choice of channels and authentication methods. It can be a challenge to get a consistent overview of the strengths and weaknesses of the available alternatives. Existing guidelines for authentication usually do not consider the specific problems in mobile phone authentication. We provide a method for evaluating and designing authentication solutions using mobile phones, using an augmented version of the Electronic Authentication Guideline.

    Ort, förlag, år, upplaga, sidor
    Boston: Springer, 2011
    Serie
    IFIP Advances in Information and Communication Technology, ISSN 1868-4238 ; 352
    Nyckelord
    Authentication, information security, mobile phone, security levels, evaluation method
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:liu:diva-70058 (URN)10.1007/978-3-642-20769-3_11 (DOI)978-3-642-20768-6 (ISBN)
    Konferens
    PrimeLife/IFIP Summer School 2010
    Tillgänglig från: 2011-08-17 Skapad: 2011-08-17 Senast uppdaterad: 2018-01-12
    2. 2-clickAuth - Optical Challenge-Response Authentication using Mobile Handsets
    Öppna denna publikation i ny flik eller fönster >>2-clickAuth - Optical Challenge-Response Authentication using Mobile Handsets
    2011 (Engelska)Ingår i: International Journal on Mobile Computing and Multimedia Communications, ISSN 1937-9412, E-ISSN 1937-9404, Vol. 3, nr 2, s. 1-18Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Internet users often have usernames and passwords at multiple web sites. To simplify things, many sites support federated identity management, which enables users to have a single account allowing them to log on to different sites by authenticating to a single identity provider. Most identity providers perform authentication using a username and password. Should these credentials be compromised, all of the user’s accounts become compromised. Therefore a more secure authentication method is desirable. This paper implements 2-clickAuth, a multimedia-based challenge-response solution which uses a web camera and a camera phone for authentication. Two-dimensional barcodes are used for the communication between phone and computer, which allows 2-clickAuth to transfer relatively large amounts of data in a short period of time. 2-clickAuth is more secure than passwords while easy to use and distribute. 2-clickAuth is a viable alternative to passwords in systems where enhanced security is desired, but availability, ease-of-use, and cost cannot be compromised. This paper implements an identity provider in the OpenID federated identity management system that uses 2-clickAuth for authentication, making 2-clickAuth available to all users of sites that support OpenID, including Facebook, Sourceforge, and MySpace.

    Ort, förlag, år, upplaga, sidor
    Hershey, USA: IGI Global, 2011
    Nyckelord
    Authentication, federated identity management, mobile computing, OpenID, QR code, trusted device
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:liu:diva-70063 (URN)10.4018/jmcmc.2011040101 (DOI)
    Tillgänglig från: 2011-08-17 Skapad: 2011-08-17 Senast uppdaterad: 2018-01-12
    3. Third-party identity management usage on the web
    Öppna denna publikation i ny flik eller fönster >>Third-party identity management usage on the web
    2014 (Engelska)Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Springer Berlin/Heidelberg, 2014, Vol. 8362 LNCS, s. 151-162Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    Many websites utilize third-party identity management services to simplify access to their services. Given the privacy and security implications for end users, an important question is how websites select their third-party identity providers and how this impacts the characteristics of the emerging identity management landscape seen by the users. In this paper we first present a novel Selenium-based data collection methodology that identifies and captures the identity management relationships between sites and the intrinsic characteristics of the websites that form these relationships. Second, we present the first large-scale characterization of the third-party identity management landscape and the relationships that makes up this emerging landscape. As a reference point, we compare and contrast our observations with the somewhat more understood third-party content provider landscape. Interesting findings include a much higher skew towards websites selecting popular identity provider sites than is observed among content providers, with sites being more likely to form identity management relationships that have similar cultural, geographic, and general site focus. These findings are both positive and negative. For example, the high skew in usage places greater responsibility on fewer organizations that are responsible for the increased information leakage cost associated with highly aggregated personal information, but also reduces the users control of the access to this information. © 2014 Springer International Publishing Switzerland.

    Ort, förlag, år, upplaga, sidor
    Springer Berlin/Heidelberg, 2014
    Serie
    Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349
    Nationell ämneskategori
    Data- och informationsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-116404 (URN)10.1007/978-3-319-04918-2_15 (DOI)2-s2.0-84900600203 (Scopus ID)9783319049175 (ISBN)
    Konferens
    15th International Conference on Passive and Active Measurement, PAM 2014
    Tillgänglig från: 2015-03-26 Skapad: 2015-03-26 Senast uppdaterad: 2018-01-24
    4. A Look at the Third-Party Identity Management Landscape
    Öppna denna publikation i ny flik eller fönster >>A Look at the Third-Party Identity Management Landscape
    2016 (Engelska)Ingår i: IEEE Internet Computing, ISSN 1089-7801, E-ISSN 1941-0131, Vol. 20, nr 2, s. 18-25Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Many websites act as relying parties (RPs) by allowing access to their services via third-party identity providers (IDPs), such as Facebook and Google. Using IDPs simplifies account creation, login activity, and information sharing across websites. However, different websites use of IDPs can have significant security and privacy implications for users. Here, the authors provide an overview of third-party identity managements current landscape. Using datasets collected through manual identification and large-scale crawling, they answer questions related to which sites act as RPs, which sites are the most successful IDPs, and how different classes of RPs select their IDPs.

    Ort, förlag, år, upplaga, sidor
    IEEE COMPUTER SOC, 2016
    Nationell ämneskategori
    Data- och informationsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-127053 (URN)10.1109/MIC.2016.38 (DOI)000372015500003 ()
    Tillgänglig från: 2016-04-13 Skapad: 2016-04-13 Senast uppdaterad: 2018-01-10
    5. Information Sharing and User Privacy in the Third-party Identity Management Landscape
    Öppna denna publikation i ny flik eller fönster >>Information Sharing and User Privacy in the Third-party Identity Management Landscape
    2015 (Engelska)Ingår i: ICT Systems Security and Privacy Protection: 30th IFIP TC 11 International Conference, SEC 2015, Hamburg, Germany, May 26-28, 2015, Proceedings / [ed] Hannes Federrath, Dieter Gollmann, Springer, 2015, s. 174-188Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    The cross-site information sharing and authorized actions of third-party identity management can have significant privacy implications for the users. In this paper, we use a combination of manual analysis of identified third-party identity management relationships and targeted case studies to (i) capture how the protocol usage and third-party selection is changing, (ii) profile what information is requested to be shared (and actions to be performed) between websites, and (iii) identify privacy issues and practical problems that occur when using multiple accounts (associated with these services). By characterizing and quantifying the third-party relationships based on their cross-site information sharing, the study highlights differences in the privacy leakage risks associated with different classes of websites, and provides concrete evidence for how the privacy risks are increasing. For example, many news and file/video-sharing sites ask users to authorize the site to post information to the third-party website. We also observe a general increase in the breadth of information that is shared across websites, and find that due to usage of multiple third-party websites, in many cases, the user can lose (at least) partial control over which identities they can merge/relate and the information that is shared/posted on their behalf.

    Ort, förlag, år, upplaga, sidor
    Springer, 2015
    Serie
    IFIP Advances in Information and Communication Technology, ISSN 1868-4238 ; 455
    Nationell ämneskategori
    Datorsystem
    Identifikatorer
    urn:nbn:se:liu:diva-117543 (URN)10.1007/978-3-319-18467-8_12 (DOI)000364779100012 ()978-3-319-18466-1 (ISBN)978-3-319-18467-8 (ISBN)
    Konferens
    30th IFIP TC 11 International Conference, SEC 2015, Hamburg, Germany, May 26-28, 2015
    Tillgänglig från: 2015-05-04 Skapad: 2015-05-04 Senast uppdaterad: 2017-03-16Bibliografiskt granskad
    6. Longitudinal Analysis of the Third-party Authentication Landscape
    Öppna denna publikation i ny flik eller fönster >>Longitudinal Analysis of the Third-party Authentication Landscape
    2016 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    Many modern websites offer single sign-on (SSO) services, which allow the user to use an existing account with a third-party website such as Facebook to authenticate. When using SSO the user must approve an app-rights agreement that specifies what data related to the user can be shared between the two websites and any actions (e.g., posting comments) that the origin website is allowed to perform on behalf of the user on the third-party provider (e.g., Facebook). Both cross-site data sharing and actions performed on behalf of the user can have significant privacy implications. In this paper we present a longitudinal study of the third-party authentication landscape, its structure, and the protocol usage, data sharing, and actions associated with individual third-party relationships. The study captures the current state, changes in the structure, protocol usage, and information leakage risks.

    Ort, förlag, år, upplaga, sidor
    Internet Society, 2016
    Nationell ämneskategori
    Datorsystem
    Identifikatorer
    urn:nbn:se:liu:diva-127301 (URN)1-891562-44-4 (ISBN)
    Konferens
    NDSS Workshop on Understanding and Enhancing Online Privacy Workshop (UEOP@NDSS).21-24 February 2016 Catamaran Resort Hotel & Spa in San Diego, California
    Anmärkning

    DOI does not work: 10.14722/ueop.2016.23008

    Tillgänglig från: 2016-04-19 Skapad: 2016-04-19 Senast uppdaterad: 2018-09-20Bibliografiskt granskad
  • 466.
    Vapen, Anna
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Byers, David
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    2-clickAuth - Optical Challenge-Response Authentication2010Ingår i: International Conference on Availability, Reliability, and Security, 2010. ARES '10, IEEE COMPUTER SOC, 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA , 2010, s. 79-86Konferensbidrag (Refereegranskat)
    Abstract [en]

    Internet users today often have usernames and passwords at multiple web sites. To simplify things, many sites support some form of federated identity management, such as OpenID, that enables users to have a single account that allows them to log on to many different sites by authenticating to a single identity provider. Most identity providers perform authentication using a username and password. Should these credentials be compromised, e. g. captured by a key logger or malware on an untrusted computer, all the users accounts become compromised. Therefore a more secure authentication method is desirable. We have implemented 2-clickAuth, an optical challenge-response solution where a web camera and a camera phone are used for authentication. Two-dimensional barcodes are used for the communication between phone and computer, which allows 2-clickAuth to transfer relatively large amounts of data in a short period of time. 2-clickAuth is considerably more secure than passwords while still being easy to use and easy to distribute to users. This makes 2-clickAuth a viable alternative to passwords in systems where enhanced security is desired, but availability, ease-of-use, and cost cannot be compromised. We have implemented an identity provider in the OpenID federated identity management system that uses 2clickAuth for authentication, making 2-clickAuth available to all users of sites that support OpenID, including Facebook, Sourceforge and MySpace.

  • 467.
    Vapen, Anna
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Mahanti, A.
    NICTA, Sydney NSW, Australia.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Third-party identity management usage on the web2014Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Springer Berlin/Heidelberg, 2014, Vol. 8362 LNCS, s. 151-162Konferensbidrag (Refereegranskat)
    Abstract [en]

    Many websites utilize third-party identity management services to simplify access to their services. Given the privacy and security implications for end users, an important question is how websites select their third-party identity providers and how this impacts the characteristics of the emerging identity management landscape seen by the users. In this paper we first present a novel Selenium-based data collection methodology that identifies and captures the identity management relationships between sites and the intrinsic characteristics of the websites that form these relationships. Second, we present the first large-scale characterization of the third-party identity management landscape and the relationships that makes up this emerging landscape. As a reference point, we compare and contrast our observations with the somewhat more understood third-party content provider landscape. Interesting findings include a much higher skew towards websites selecting popular identity provider sites than is observed among content providers, with sites being more likely to form identity management relationships that have similar cultural, geographic, and general site focus. These findings are both positive and negative. For example, the high skew in usage places greater responsibility on fewer organizations that are responsible for the increased information leakage cost associated with highly aggregated personal information, but also reduces the users control of the access to this information. © 2014 Springer International Publishing Switzerland.

  • 468.
    Vapen, Anna
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Mahanti, Anirban
    NICTA, Australia.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    A Look at the Third-Party Identity Management Landscape2016Ingår i: IEEE Internet Computing, ISSN 1089-7801, E-ISSN 1941-0131, Vol. 20, nr 2, s. 18-25Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Many websites act as relying parties (RPs) by allowing access to their services via third-party identity providers (IDPs), such as Facebook and Google. Using IDPs simplifies account creation, login activity, and information sharing across websites. However, different websites use of IDPs can have significant security and privacy implications for users. Here, the authors provide an overview of third-party identity managements current landscape. Using datasets collected through manual identification and large-scale crawling, they answer questions related to which sites act as RPs, which sites are the most successful IDPs, and how different classes of RPs select their IDPs.

  • 469.
    Vapen, Anna
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Mahanti, Anirban
    NICTA, Australia.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Information Sharing and User Privacy in the Third-party Identity Management Landscape2015Ingår i: ICT Systems Security and Privacy Protection: 30th IFIP TC 11 International Conference, SEC 2015, Hamburg, Germany, May 26-28, 2015, Proceedings / [ed] Hannes Federrath, Dieter Gollmann, Springer, 2015, s. 174-188Konferensbidrag (Refereegranskat)
    Abstract [en]

    The cross-site information sharing and authorized actions of third-party identity management can have significant privacy implications for the users. In this paper, we use a combination of manual analysis of identified third-party identity management relationships and targeted case studies to (i) capture how the protocol usage and third-party selection is changing, (ii) profile what information is requested to be shared (and actions to be performed) between websites, and (iii) identify privacy issues and practical problems that occur when using multiple accounts (associated with these services). By characterizing and quantifying the third-party relationships based on their cross-site information sharing, the study highlights differences in the privacy leakage risks associated with different classes of websites, and provides concrete evidence for how the privacy risks are increasing. For example, many news and file/video-sharing sites ask users to authorize the site to post information to the third-party website. We also observe a general increase in the breadth of information that is shared across websites, and find that due to usage of multiple third-party websites, in many cases, the user can lose (at least) partial control over which identities they can merge/relate and the information that is shared/posted on their behalf.

  • 470.
    Vapen, Anna
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Mahanti, Anirban
    NICTA, Australia.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, IISLAB - Laboratoriet för intelligenta informationssystem. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Information Sharing and User Privacy in the Third-party Identity Management Landscape2015Ingår i: Proc. ACM Conference on Data and Application Security and Privacy (ACM CODASPY), ACM Digital Library, 2015, s. 151-153Konferensbidrag (Refereegranskat)
    Abstract [en]

    Third-party identity management services enable cross-site information sharing, making Web access seamless but also raise significant privacy implications for the users. Using a combination of manual analysis of identified third-party identity management relationships and targeted case studies we capture how the protocol usage and third-party selection is changing, profile what information is requested to be shared (and actions to be performed) between websites, and identify privacy issues and practical problems that occur when using multiple accounts (associated with these services). The study highlights differences in the privacy leakage risks associated with different classes of websites, and shows that the use of multiple third-party websites, in many cases, can cause the user to lose (at least) partial control over which information is shared/posted on their behalf.

  • 471.
    Vapen, Anna
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Longitudinal Analysis of the Third-party Authentication Landscape2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    Many modern websites offer single sign-on (SSO) services, which allow the user to use an existing account with a third-party website such as Facebook to authenticate. When using SSO the user must approve an app-rights agreement that specifies what data related to the user can be shared between the two websites and any actions (e.g., posting comments) that the origin website is allowed to perform on behalf of the user on the third-party provider (e.g., Facebook). Both cross-site data sharing and actions performed on behalf of the user can have significant privacy implications. In this paper we present a longitudinal study of the third-party authentication landscape, its structure, and the protocol usage, data sharing, and actions associated with individual third-party relationships. The study captures the current state, changes in the structure, protocol usage, and information leakage risks.

  • 472.
    Vapen, Anna
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    2-clickAuth - Optical Challenge-Response Authentication using Mobile Handsets2011Ingår i: International Journal on Mobile Computing and Multimedia Communications, ISSN 1937-9412, E-ISSN 1937-9404, Vol. 3, nr 2, s. 1-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Internet users often have usernames and passwords at multiple web sites. To simplify things, many sites support federated identity management, which enables users to have a single account allowing them to log on to different sites by authenticating to a single identity provider. Most identity providers perform authentication using a username and password. Should these credentials be compromised, all of the user’s accounts become compromised. Therefore a more secure authentication method is desirable. This paper implements 2-clickAuth, a multimedia-based challenge-response solution which uses a web camera and a camera phone for authentication. Two-dimensional barcodes are used for the communication between phone and computer, which allows 2-clickAuth to transfer relatively large amounts of data in a short period of time. 2-clickAuth is more secure than passwords while easy to use and distribute. 2-clickAuth is a viable alternative to passwords in systems where enhanced security is desired, but availability, ease-of-use, and cost cannot be compromised. This paper implements an identity provider in the OpenID federated identity management system that uses 2-clickAuth for authentication, making 2-clickAuth available to all users of sites that support OpenID, including Facebook, Sourceforge, and MySpace.

  • 473.
    Vapen, Anna
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Shahmehri, Nahid
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Security Levels for Web Authentication using Mobile Phones2011Ingår i: Privacy and Identity Management for Life / [ed] Simone Fischer-Hübner, Penny Duquenoy, Marit Hansen, Ronald Leenes and Ge Zhang, Boston: Springer , 2011, s. 130-143Konferensbidrag (Refereegranskat)
    Abstract [en]

    Mobile phones offer unique advantages for secure authentication: they are small and portable, provide multiple data transfer channels, and are nearly ubiquitous. While phones provide a flexible and capable platform, phone designs vary, and the security level of an authentication solution is influenced by the choice of channels and authentication methods. It can be a challenge to get a consistent overview of the strengths and weaknesses of the available alternatives. Existing guidelines for authentication usually do not consider the specific problems in mobile phone authentication. We provide a method for evaluating and designing authentication solutions using mobile phones, using an augmented version of the Electronic Authentication Guideline.

  • 474.
    Vapen, Anna
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Security Levels for Web Authentication using Mobile Phones2010Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Mobile phones offer unique advantages for secure authentication: they are small and portable, provide multiple data transfer channels, and are nearly ubiquitous. While phones provide a flexible and capable platform, phone designs vary, and the security level of an authentication solution is influenced by the choice of channels and authentication methods. It can be a challenge to get a consistent overview of the strengths and weaknesses of the available alternatives. In this paper we provide a method for evaluating and designing authentication solutions using mobile phones. The method also considers availability and usability, which are often overlooked factors. The goal is to help developers to create secure authentication, considering the user's priorities on security, availability and usability.

  • 475.
    Varghese, Benoy
    et al.
    NICTA and University of New South Wales (UNSW), Australia.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Jourjon, Guillaume
    NICTA, Sydney, Australia.
    Mahanti, Anirban
    NICTA, Sydney, Australia.
    Shenoy, Prashant
    University of Massachusetts, USA.
    Greening Web Servers: A Case for Ultra Low-power Web Servers2014Ingår i: Proc. International Green Computing Conference (IGCC), IEEE Press, 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we investigate the feasibility of running web servers on low-power micro-computing boards, with emphasis on analysing the tradeoffs between power and performance. Today, small-to-medium scale enterprises, NGOs, universities typically deploy an architecture where frontend servers deliver static content and backend servers the dynamic content.   Experimentation using an ARM-based Raspberry Pi system shows that, for static content, Raspberry Pi achieves similar response times to that of a typical tower server running on standard hardware.   Although, the Raspberry Pi is found unsuitable for serving dynamic content, our findings show that many of these small-to-medium scale organisations can achieve large energy savings by using low-power servers for serving the static content.

  • 476.
    Våleman, Adrian
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Automatgenerering av transaktionshanteringsprocedurer2013Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In a database environment, when you create or alter tables you often want to have a basic interface for standard operations such as insert, delete and update. This thesis report covers an analysis of what programs there are on the market for generating such interfaces and compares them against the demands of a real company. The analysis showed that none of the programs were completely meeting the requirements and therefore an own implementation of an interface generating program was created. The result is a PL/SQL program capable of generating files, storing them in a version handling system and executing the files into the database.

  • 477.
    Wei, Fang
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    TEDI: Efficient Shortest Path Query Answering on Graphs2012Ingår i: Graph Data Management: Techniques and Applications, IGI Global, 2012Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 478.
    Wei-Kleiner, Fang
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Contributions of LiU/ADIT to Steiner Tree Computation over Large Graphs2012Ingår i: Advances in secure and networked information systems: the ADIT perspective ; Festschrift in honor of professor Nahid Shahmehri / [ed] Patrick Lambrix, Linköping: Linköping University Electronic Press, 2012, s. 131-138Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    This book contains contributions by current and former colleagues and PhD students of professor Nahid Shahmehri in celebration of her 60th birthday. Although it would be difficult to cover the full range of her academic contributions, we have at least been able to hint the importance and the breadth of her work. We have chosen the title ‘Advances in Secure and Networked Information Systems - The ADIT Perspective’ as many of the contributions of Nahid and her group have been in these areas, given a fairly broad interpretation of “networked information systems”. In this collection we have gathered both republications of past work as well as newly written articles.

  • 479.
    Wei-Kleiner, Fang
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Finding nearest neighbors in road networks: a tree decomposition method2013Ingår i: EDBT '13 Proceedings of the Joint EDBT/ICDT 2013 Workshops, New York: Association for Computing Machinery (ACM), 2013, s. 233-240Konferensbidrag (Refereegranskat)
    Abstract [en]

    Finding k Nearest Neighbors in one category of POIs (point of interests) belongs to the most frequently issued queries in the navigating systems or online maps. This problem can be formulated as given a graph G(V, E), a vertex u and SV, finding k nearest neighbors of u in S. Classic Dijkstra's algorithm offers an optimal solution if S = V holds, but the performance deteriorates as S is of smaller size. Other approaches such as pre-computing and storing all the shortest distances require too much storage, thus suffer from drawbacks of scalability.

    To address these problems, we propose TIkNN (stands for Tree decomposition-based Indexing for kNN), an indexing and query processing scheme for kNN query answering. TIkNN is based on the tree decomposition methodology. The graph is first decomposed into a tree in which each node (a.k.a. bag) contains more than one vertex from graph. The shortest paths are stored in such bags and these local paths together with the tree are the components of the index of the graph. Based on this index, step-wise query processing over the tree can be executed to find the nearest neighbors.

    Our experimental results show that TIkNN offers orders-of-magnitude performance improvement over Dijkstra's algorithm on query answering, while the storage requirement for the index structure is relatively small.

  • 480.
    Wei-Kleiner, Fang
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Tree decomposition-based indexing for efficient shortest path and nearest neighbors query answering on graphs2016Ingår i: Journal of computer and system sciences (Print), ISSN 0022-0000, E-ISSN 1090-2724, Vol. 82, nr 1, s. 23-44Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We propose TEDI, an indexing for solving shortest path, and k Nearest Neighbors (kNN) problems. TEDI is based on the tree decomposition methodology. The graph is first decomposed into a tree in which the node contains vertices. The shortest paths are stored in such nodes. These local shortest paths together with the tree structure constitute the index of the graph. Based on this index, algorithms can be executed to solve the shortest path, as well as the kNN problem more efficiently. Our experimental results show that TEDI offers orders-of-magnitude performance improvement over existing approaches on the index construction time, the index size and the query answering. (C) 2015 Elsevier Inc. All rights reserved.

  • 481.
    Wei-Kleiner, Fang
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Dragisic, Zlatan
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Abduction Framework for Repairing Incomplete EL Ontologies:  Complexity Results and Algorithms2014Ingår i: Proceedings of the 28th AAAI Conference on Artificial Intelligence, Palo Alto, CA, USA: AAAI Press, 2014, s. 1120-1127Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper we consider the problem of repairing  missing is-a relations in ontologies.We formalize the problem as a generalized TBox abduction problem (GTAP). Based on this abduction framework, we  present complexity results for the existence, relevance and necessity decision problems for the GTAP with and without some specific preference relations for ontologies that can be represented using a member of the EL family of description logics. Further, we present algorithms for finding solutions, a system as well as experiments.

  • 482.
    Williamson, Carey
    et al.
    University of Calgary, Canada.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    On Zipf Models for Probabilistic Piece Selection in P2P Stored Media Streaming2013Ingår i: IEEE International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS), 2013, Institute of Electrical and Electronics Engineers (IEEE), 2013, s. 161-171Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Zipf distribution is widely used to model Web site popularity, video popularity, and file referencing behavior. In recent published work, we proposed and evaluated a Zipf-based policy for probabilistic piece selection in Peer-to-Peer (P2P) media streaming. In this current paper, we revisit this Zipf model in more detail, and identify two fundamentally different modeling approaches, namely regenerative versus degenerative Zipf models. We illustrate the differences between the two models, provide refined analytical models for each, and validate the models with simulations in the context of P2P media streaming. The results show that the regenerative model is more appropriate for P2P streaming, because of its stronger sequential progress.

  • 483.
    Wächter, Thomas
    et al.
    Biotechnologisches Zentrum, TU Dresden, Germany.
    Tan, He
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Wobst, André
    Biotechnologisches Zentrum, TU Dresden, Germany.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Schroeder, Michael
    Biotechnologisches Zentrum, TU Dresden, Germany.
    A Corpus-driven Approach for Design, Evolution and Alignment of Ontologies2006Ingår i: Winter Simulation Conference,2006, 2006, s. 1595-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Bio-ontologies are hierarchical vocabularies, which are used to annotate other data sources such as sequence and structure databases. With the wide use of ontologies their integration, design, and evolution becomes an important problem. We show how textmining on relevant text corpora can be used to identify matching ontology terms of two separate ontologies and to propose new ontology terms for a given term. We evaluate these approaches on the GeneOntology.

  • 484.
    Yan, Jeff
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Bourquard, Aurelien
    MIT, MA 02139 USA.
    POSTER: Who was Behind the Camera? - Towards Some New Forensics2017Ingår i: CCS17: PROCEEDINGS OF THE 2017 ACM SIGSAC CONFERENCE ON COMPUTER AND COMMUNICATIONS SECURITY, ASSOC COMPUTING MACHINERY , 2017, s. 2595-2597Konferensbidrag (Refereegranskat)
    Abstract [en]

    We motivate a new line of image forensics, and propose a novel approach to photographer identification, a rarely explored authorship attribution problem. A preliminary proof-of-concept study shows the feasibility of our method. Our contribution is a forensic method for photographer de-anonymisation, and the method also imposes a novel privacy threat.

  • 485.
    Zhang, Song
    et al.
    University of Calgary, Canada.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Eager, Derek
    University of Saskatchewan, Canada.
    Li, Zongpeng
    University of Calgary, Canada.
    Mahanti, Anirban
    NICTA, Australia.
    Dynamic File Bundling for Large-scale Content Distribution2012Ingår i: IEEE Conference on Local Computer Networks (LCN) 2012, IEEE , 2012, s. 601-609Konferensbidrag (Refereegranskat)
    Abstract [en]

    One highly-scalable approach to content delivery is to harness the upload bandwidth of the clients. Peer-assisted content delivery systems have been shown to effectively offload the servers of popular files, as the request rates of popular content enable the formation of self-sustaining torrents, where the entire content of the file is available among the peers themselves. However, for less popular files, these systems are less helpful in offloading servers. With a long tail of mildly popular content, with a high aggregate demand, a large fraction of the file requests must still be handled by servers. In this paper, we present the design, implementation, and evaluation of a dynamic file bundling system, where peers are requested to download content which they may not otherwise download in order to "inflate" the popularity of less popular files. Our system introduces the idea of a super bundle, which consists of a large catalogue of files. From this catalogue, smaller bundles, consisting of a small set of files, can dynamically be assigned to individual users. The system can dynamically adjust the number of downloaders of each file and thus enables the popularity inflation to be optimized according to current file popularities and the desired tradeoff between download times and server resource usage. The system is evaluated on PlanetLab.

  • 486.
    Zhang, Song
    et al.
    University of Calgary Canada.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Eager, Derek
    University of Saskatchewan, Canada.
    Li, Zongpeng
    University of Calgary Canada.
    Mahanti, Anirban
    NICTA, Australia.
    Towards a Dynamic File Bundling System for Large-scale Content Distribution2011Ingår i: Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS 2011), 2011, s. 472-474Konferensbidrag (Refereegranskat)
    Abstract [en]

    Peer-assisted content delivery systems can provide scalable download service for popular files. For mildly popular content, however, these systems are less helpful in offloading servers as the request rate for less popular files may not enable formation of self-sustaining torrents (where the entire content of the file is available among the peers themselves). As there typically is a long tail of mildly popular content, with a high aggregate demand, a large fraction of the file requests must still be handled by servers, and is not off-loadable to peers. Bundling approaches have been proposed where peers are requested to download content which they may not otherwise be interested in order to ``inflate'' the popularity of less popular files. We present the design and implementation of a dynamic bundling system, in which a large number of files may be bundled to form a super bundle. From this super bundle, smaller individual bundles, consisting of a small set of files, can dynamically be assigned to individual users. Our system has the capability to dynamically adjust the number of downloaders of each file, thus allowing popularity inflation to be optimized according to current file popularities.

  • 487.
    Åberg, Cecile
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    An Agent-based Framework for Integrating Workflows and Web Services2005Ingår i: Proceedings of the IEEE WETICE Workshop on Agent-based Computing for Enterprise Collaboration,2005, Institute of Electrical and Electronics Engineers (IEEE), 2005, s. 27-32Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Semantic Web will enable business-to-business in new ways. In this context, organizations will need to make use of the new opportunities that the Semantic Web technology provides. However, this should be done without major requirements on the organization. To this aim we propose an agent-based model for integrating the usage of the Semantic Web (represented as Web services) into an organization's work routines (represented by Workflows). Further, we describe a possible architecture for our approach, and briefly show its feasibility with an implemented prototype.

  • 488.
    Åberg, Cecile
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Takkinen, Juha
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    sButler: A Mediator between Organizations' Workflows and the Semantic Web2005Ingår i: Proceedings of the WWW 2005 Workshop on Web Service Semantics: Towards Dynamic Business Integration,2005, 2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Semantic Web will enable business-to-business in new ways. In this context, organizations will need to incorporate the Semantic Web into their work routines. However, this should be done in a way that does not require major changes in the organization. To this aim we propose a model for integrating the usage of the Semantic Web into an organization's work routines. The central component of the model is an sButler, a software agent that mediates between the organization and the Semantic Web. Further, we describe an architecture for one of the important parts of the sButler, show its feasibility with an implemented prototype, and discuss a test using a travel scenario.

  • 489.
    Åberg, Cecile
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Åberg, Johan
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lambrix, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    A Platform to Evaluate the Technology for Service Discovery in the Semantic Web2006Ingår i: National Conference on Artificial Intelligence AAAI-06,2006, 2006, s. 1253-1258Konferensbidrag (Refereegranskat)
    Abstract [en]

    Since the description of the Semantic Web paradigm in 2001, technology has been proposed to allow its deployment and use. However, there is not yet any large and widely deployed set of semantically annotated Web resources available. As a result, it is not possible to evaluate the use of the technology in a real environment, and several assumptions about how the Semantic Web should work are emerging. In order to further investigate these assumptions and the related technology, we propose a simulation and evaluation platform. The platform provides tools to create SemanticWeb simulations using different technologies for different purposes, and to evaluate their performance. In this paper we introduce the model of the platform and describe the current implementation. The implementation facilitates the integration of technology for an essential operation on the Semantic Web, namely Semantic Web service discovery. We illustrate the use of the platform in a case study by implementing a SemanticWeb where the Jade multi-agent platform provides the framework to describe the agents, and a number of existing Semantic Web technologies are embedded in agent behavior.

  • 490.
    Åsberg, Mikael
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Strömbäck, Lena
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Bioinformatics: From Disparate Web Services to Semantics and Interoperability2010Ingår i: International Journal of Advances in Software, ISSN 1942-2628, Vol. 3, nr 3-4, s. 396-406Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the field of bioinformatics, there exists a large number of web service providers and many competing standards regarding how data should be represented and interfaced. However, these web services are often hard to use for a non-programmer and it can be especially hard to understand how different services can be used together to create scientific workflows. In this paper we have performed a literature study to identify problems involved in developing interoperable webservices for the bioinformatics community and steps taken by other projects to address them. We have also conducted a case study by developing our own bioinformatic web service to further investigate these problems. Based on our case study we have identified a number of design issues important to consider when designing web services. The paper is concluded by discussing current approaches aimed at making web services easier to use and by presenting our own proposal of an easy-to-use solution for integrating information from web services.

  • 491.
    Örnberg, Dennis
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Comparison and implementation of graph visualization algorithms using JavaFX2016Självständigt arbete på grundnivå (högskoleexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Graph drawing is an important area in computer science and it has many different application areas. For example, graphs can be used to visualize structures like networks and databases. When the graphs are really big, however, it becomes difficult to draw them so that the user can get a good overview of the whole graph and all of its data. There exist a number of different algorithms that can be used to draw graphs, but they have a lot of differences. The goal of this report was to find an algorithm that produces graphs of satisfying quality in little time for the purpose of ontology engineering, and implement it using a platform that visualizes the graph using JavaFX. It is supposed to work on a visualization table with a touch display. A list of criteria for both the algorithm and the application was made to ensure that the final result would be satisfactory. A comparison between four well-known graph visualization algorithms was made and “GEM” was found to be the best suited algorithm for visualizing big graphs. The two platforms Gephi and Prefux were introduced and compared to each other, and the decision was made to implement the algorithm in Prefux since it has support for JavaFX. The algorithm was implemented and evaluated, it was found to produce visually pleasing graphs within a reasonable time frame. A modified version of the algorithm called GEM-2 was also introduced, implemented and evaluated. With GEM-2, the user can pick a specific number of levels to be expanded at first, additional levels can then be expanded by hand. This greatly improves the performance when there is no need to expand the whole graph at once, however, it also increases the amount of edge crossings which makes the graph less visually pleasing.

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