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  • 301.
    Duarte, Nuno O.
    et al.
    Univ Lisbon, INESC ID IST, Lisbon, Portugal..
    Yalew, Sileshi Demesie
    KTH.
    Santos, Nuno
    Univ Lisbon, INESC ID IST, Lisbon, Portugal..
    Correia, Miguel
    Univ Lisbon, INESC ID IST, Lisbon, Portugal..
    Leveraging ARM TrustZone and Verifiable Computing to Provide Auditable Mobile Functions2018In: Proceedings Of The 15Th EAI International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services  (MOBIQUITOUS 2018), Association for Computing Machinery (ACM), 2018, p. 302-311Conference paper (Refereed)
    Abstract [en]

    The increase of personal data on mobile devices has been followed by legislation that forces service providers to process and maintain users' data under strict data protection policies. In this paper, we propose a new primitive for mobile applications called auditable mobile function (AMF) to help service providers enforcing such policies by enabling them to process sensitive data within users' devices and collecting proofs of function execution integrity. We present SafeChecker, a computation verification system that provides mobile application support for AMFs, and evaluate the practicality of different usage scenario AMFs on TrustZone-enabled hardware.

  • 302.
    Dubrova, Elena
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Learning Fault-Tolerance from Nature2008In: BEC 2008: 2008 INTERNATIONAL BIENNIAL BALTIC ELECTRONICS CONFERENCE, PROCEEDINGS, 2008, p. 51-58Conference paper (Refereed)
    Abstract [en]

    In the last decade, there has been a considerable increase of interest in fault-tolerant computing due to dependability problems related to process scaling, embedded software, and ubiquitous computing. In this paper, we discuss an approach to fault-tolerance which is inspired by biological systems. Biological systems are capable of maintaining their functionality tinder a variety of genetic changes and external perturbations. They have natural self-healing, self-maintaining, self-replicating and self-assembling mechanisms. We present experimental and numerical evidence that the intrinsic fault-tolerance of biological systems is due to the dynamical phase in which the gene regulatory network operates. The dynamical phase is, in turn, determined by the subtle way in which redundancy is allocated in the network. By understanding the principles of redundancy allocation at the genetic level, we may find ways to build chips that possess the inherent fault-tolerance of biological systems.

  • 303.
    Duchamp, Daniel J.
    et al.
    Columbia University.
    Feiner, Steven K.
    Columbia University.
    Maguire Jr., Gerald Q.
    Columbia University, Department of Computer Science.
    Software technology for wireless mobile computing1991In: IEEE Network, ISSN 0890-8044, E-ISSN 1558-156X, Vol. 5, no 6, p. 12-18Article in journal (Refereed)
    Abstract [en]

    Some of the possibilities and requirements for mobile computing on wireless local area networks (LANs) are discussed from the systems software viewpoint. The design of the Student Electronic Notebook (SEN) is sketched to provide a partial catalog of problems in building a real system for wireless mobile computing. This project was initiated to investigate the potential of wireless mobile computing to reshape education. Some of the key directions for research in software technology for wireless, mobile computing are examined. Some of the authors' experience with wireless LANs is related.

  • 304.
    Dán, György
    et al.
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Bobba, Rakesh B.
    University of Illinois at Urbana-Champaign.
    Gross, George
    University of Illinois at Urbana-Champaign.
    Campbell, Roy H.
    University of Illinois at Urbana-Champaign.
    Cloud Computing for the Power Grid: From Service Composition to Assured Clouds2013In: Proceedings of the 5th USENIX Workshop on Hot Topics in Cloud Computing (HotCloud), June 2013, USENIX Association , 2013Conference paper (Refereed)
    Abstract [en]

    The electric power industry is one of the few industries where cloud computing has not yet found much adoption, even though electric power utilities rely heavily on communications and computation to plan, operate and analyze power systems. In this paper we explore the reasons for this phenomenon. We identify a variety of power system applications that could benefit from cloud computing. We then discuss the security requirements of these applications, and explore the design space for providing the security properties through application layer composition and via assured cloud computing. We argue that a combination of these two approaches will be needed to meet diverse application requirements at a cost that can justify the use of cloud computing.

  • 305.
    Düring, Morgan
    et al.
    KTH, Superseded Departments (pre-2005), Microelectronics and Information Technology, IMIT.
    Öberg, Johnny
    Implementation of Revolver Type Processor Using Grammar-based Methodology2002In: Proceedings of the 2nd Swedish System on Chip conference, 2002Conference paper (Refereed)
  • 306.
    Ebrahimi, Masoumeh
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronics, Electronic and embedded systems.
    Daneshtalab, Masoud
    MDH.
    EbDa: A New Theory on Design and Verification of Deadlock-free Interconnection Networks2017In: In Proceedings of ISCA ’17, ACM Press, 2017, p. 1-13Conference paper (Refereed)
    Abstract [en]

    Freedom from deadlock is one of the most important issues whendesigning routing algorithms in on-chip/off-chip networks. Manyworks have been developed upon Dally’s theory proving that a networkis deadlock-free if there is no cyclic dependency on the channeldependency graph. However, finding such acyclic graph has beenvery challenging, which limits Dally’s theory to networks with a lownumber of channels. In this paper, we introduce three theorems thatdirectly lead to routing algorithms with an acyclic channel dependencygraph.We also propose the partitioning methodology, enablinga design to reach the maximum adaptiveness for the n-dimensionalmesh and k-ary n-cube topologies with any given number of channels.In addition, deadlock-free routing algorithms can be derivedranging from maximally fully adaptive routing down to deterministicrouting. The proposed theorems can drastically remove thedifficulties of designing deadlock-free routing algorithms.

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    EbDa-ISCA17
  • 307.
    Edin, Fredrik
    et al.
    KTH, School of Computer Science and Communication (CSC), Computational Biology, CB.
    Klingberg, Torkel
    Johansson, Par
    McNab, Fiona
    Tegner, Jesper
    Compte, Albert
    Mechanism for top-down control of working memory capacity2009In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 106, no 16, p. 6802-6807Article in journal (Refereed)
    Abstract [en]

    Working memory capacity, the maximum number of items that we can transiently store in working memory, is a good predictor of our general cognitive abilities. Neural activity in both dorsolateral prefrontal cortex and posterior parietal cortex has been associated with memory retention during visuospatial working memory tasks. The parietal cortex is thought to store the memories. However, the role of the dorsolateral prefrontal cortex, a top-down control area, during pure information retention is debated, and the mechanisms regulating capacity are unknown. Here, we propose that a major role of the dorsolateral prefrontal cortex in working memory is to boost parietal memory capacity. Furthermore, we formulate the boosting mechanism computationally in a biophysical cortical microcircuit model and derive a simple, explicit mathematical formula relating memory capacity to prefrontal and parietal model parameters. For physiologically realistic parameter values, lateral inhibition in the parietal cortex limits mnemonic capacity to a maximum of 2-7 items. However, at high loads inhibition can be counteracted by excitatory prefrontal input, thus boosting parietal capacity. Predictions from the model were confirmed in an fMRI study. Our results show that although memories are stored in the parietal cortex, interindividual differences in memory capacity are partly determined by the strength of prefrontal top-down control. The model provides a mechanistic framework for understanding top-down control of working memory and specifies two different contributions of prefrontal and parietal cortex to working memory capacity.

  • 308.
    Ejdemark, Johan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics.
    Automatisk detektering av andning2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Hammed Hammid Mohammed, universitetsadjunkt vid KTH i Flemingsberg gav uppdragetatt utveckla en mobil kontaktlös andningsbevakare för spädbarn och äldre i form av en mobilapplikationsom använder sig av kameran för att detektera fel i andningen. Denna skullefungera som ett billigare och enklare alternativ till konventionella andningsbevakningsinstrument.Uppgiften utfördes genom att först genomföra en litteraturstudie för att finna olikaalgoritmer och matematiska modeller att implementera och testa. Andra steget var att testade mest lämpade algoritmerna och matematiska modellerna i en datorprototyp gjord i Matlabför att se ifall dessa fungerade som det var tänkt. Tredje steget var att föra över datorprototypensalgoritmer så fullständigt som möjligt till en mobilapplikation.Arbetet resulterade i en algoritm, implementerbar i mobiltelefon, som kan ingå som indikationpå att andning pågår. Detta föregicks av tester av olika parametrar såsom belysning, kontraster,avstånd, position och vinklar mellan mobilkameran och försökspersonen. Testernavisade att stark ljussättning, goda kontraster mellan försöksperson och bakgrund samt rättavstånd och position mellan kamera och försöksperson gav goda resultat.Resultatet i sin helhet gav insikten att användandet av den matematiska algoritmen FFT (FastFourier Transform) kan ingå som indikator på att det är andning som detekteras.

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  • 309.
    Eklund Kavtaradze, Gustav
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Webbapplikationssäkerhet2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Security in applications, to protect users and information, is becoming increasingly importantas society is becoming more digitized. During the duration of this report two major informationleaks, of sensitive Swedish classified information, occurred. The aim of this report is to findwhat security risks exist for webapplications, general measures that can be implemented to address these risks and how The General Data Protection Regulation (GDPR) is related to securityin applications. In order to achieve these general measures a security evaluation method was alsoused to be able to evaluate how the various measures protect webapplications, and function asrequired. The results of this report provide a general list of actions that should be implementedin application backends, but to provide a similar for the frontend more wokrs is required, wherethe frontend action list in this report is minimal. The safety evaluation method also proved to bea part of the action lists in order to be able to test the security even on operational applications.The results of the GDPR survey showed that no specific requirements are set from GDPR,instead the law has the task of raising the priority by making the consequences that can arisefrom incorrect handling of users’ personal data more serious / costly to the organization

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    g-kavtaradze-exjobb-2021-02-12.pdf
  • 310.
    Ekstedt, Erik
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Speech, Music and Hearing, TMH.
    Skantze, Gabriel
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Speech, Music and Hearing, TMH.
    TurnGPT: a Transformer-based Language Model for Predicting Turn-taking in Spoken Dialog2020In: Findings of the Association for Computational Linguistics: EMNLP 2020, Online: Association for Computational Linguistics (ACL) , 2020, p. 2981-2990Conference paper (Refereed)
    Abstract [en]

    Syntactic and pragmatic completeness is known to be important for turn-taking prediction, but so far machine learning models of turn-taking have used such linguistic information in a limited way. In this paper, we introduce TurnGPT, a transformer-based language model for predicting turn-shifts in spoken dialog. The model has been trained and evaluated on a variety of written and spoken dialog datasets. We show that the model outperforms two baselines used in prior work. We also report on an ablation study, as well as attention and gradient analyses, which show that the model is able to utilize the dialog context and pragmatic completeness for turn-taking prediction. Finally, we explore the model’s potential in not only detecting, but also projecting, turn-completions.

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  • 311.
    Ekstedt, Mathias
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Network and Systems Engineering.
    Afzal, Zeeshan
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Network and Systems Engineering.
    Mukherjee, Preetam
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Network and Systems Engineering. Digital University Kerala, Thiruvananthapuram, India.
    Hacks, Simon
    Stockholm University, Stockholm, Sweden.
    Lagerström, Robert
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Network and Systems Engineering.
    Yet another cybersecurity risk assessment framework2023In: International Journal of Information Security, ISSN 1615-5262, E-ISSN 1615-5270, Vol. 22, no 6, p. 1713-1729Article in journal (Refereed)
    Abstract [en]

    IT systems pervade our society more and more, and we become heavily dependent on them. At the same time, these systems are increasingly targeted in cyberattacks, making us vulnerable. Enterprise and cybersecurity responsibles face the problem of defining techniques that raise the level of security. They need to decide which mechanism provides the most efficient defense with limited resources. Basically, the risks need to be assessed to determine the best cost-to-benefit ratio. One way to achieve this is through threat modeling; however, threat modeling is not commonly used in the enterprise IT risk domain. Furthermore, the existing threat modeling methods have shortcomings. This paper introduces a metamodel-based approach named Yet Another Cybersecurity Risk Assessment Framework (Yacraf). Yacraf aims to enable comprehensive risk assessment for organizations with more decision support. The paper includes a risk calculation formalization and also an example showing how an organization can use and benefit from Yacraf.

  • 312.
    Ekstedt, Mathias
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Network and Systems Engineering.
    Rychkova, I.
    University Paris 1, Pantheon-Sorbonne, France.
    Message from the EDOC 2019 workshop and demo chairs2019In: Proceedings 23rd IEEE International Enterprise Distributed Object Computing Workshop, EDOCW 2019, Institute of Electrical and Electronics Engineers Inc. , 2019, Vol. 2019-October, article id 8907332Conference paper (Refereed)
  • 313.
    Ekstedt, Mirjam
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Human Communication Science.
    Coping with complexity: Sensemaking in specialised home care2016In: Researching Patient Safety and Quality in Healthcare: A Nordic Perspective, CRC Press , 2016, p. 195-209Chapter in book (Other academic)
  • 314.
    Elffers, Jan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Nordström, Jakob
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Divide and conquer: Towards faster pseudo-boolean solving2018In: IJCAI'18: Proceedings of the 27th International Joint Conference on Artificial Intelligence, International Joint Conferences on Artificial Intelligence , 2018, p. 1291-1299Conference paper (Refereed)
    Abstract [en]

    The last 20 years have seen dramatic improvements in the performance of algorithms for Boolean satisfiability-so-called SAT solvers-and today conflict-driven clause learning (CDCL) solvers are routinely used in a wide range of application areas. One serious short-coming of CDCL, however, is that the underlying method of reasoning is quite weak. A tantalizing solution is to instead use stronger pseudo-Boolean (PB) reasoning, but so far the promise of exponential gains in performance has failed to materialize-the increased theoretical strength seems hard to harness algorithmically, and in many applications CDCL-based methods are still superior. We propose a modified approach to pseudo-Boolean solving based on division instead of the saturation rule used in [Chai and Kuehlmann'05] and other PB solvers. In addition to resulting in a stronger conflict analysis, this also improves performance by keeping integer coefficient sizes down, and yields a very competitive solver as shown by the results in the Pseudo-Boolean Competitions 2015 and 2016.

  • 315.
    El-khoury, Jad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Berezovskyi, Andrii
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Nyberg, Mattias
    Scania CV AB Sodertalje, Sodertalje, Sweden..
    An industrial evaluation of data access techniques for the interoperability of engineering software tools2019In: Journal of Industrial Information Integration, ISSN 2467-964X, E-ISSN 2452-414X, Vol. 15, p. 58-68Article in journal (Refereed)
    Abstract [en]

    New industrial initiatives such as Industrie 4.0 rely on digital end-to-end engineering across the entire product lifecycle, which in turn depends on the ability of the supporting software tools to interoperate. A tool interoperability approach based on Linked Data, and the OASIS OSLC standard, has the potential to provide such integration, where each software tool can expose its information and services to other tools using the web as a common technology base. In this paper, we report on our negative findings when attempting to use existing ontology-based Linked Data access techniques to expose and manipulate the structured content managed in engineering tools. Such techniques typically target the Data Access Layer (DAL) of a tool to access and manipulate its content, with the assumption that sufficient information and control is available within this layer to automate the process. Based on a case study with the truck manufacturer Scania CV AB, our study finds that an engineering tool controls its artefacts using business logic that is not necessarily reflected at the data layer. This renders such ontology-based access techniques inadequate. Instead we propose an alternative Linked Data extraction architecture that can mitigate the identified shortcomings. While less automated compared to the existing solutions, the proposed architecture is realised as a standalone library that can still facilitate the extraction process.

  • 316.
    El-khoury, Jad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Redell, Ola
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Törngren, Martin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Integrating views in a multi-view modelling environment2005Conference paper (Refereed)
    Abstract [en]

    The development of modern technical systems requires the close collaboration of various specialist teams and engineering disciplines in order to reach the expected complex functionality. Even though working with the same system towards the same goal, developers from the different domains use their own specific tools, providing their own specific views of the system to be developed. For the successful integration of the efforts from each of these disciplines, the different views produced need to be appropriately integrated, preventing any inconsistencies and divergences from creeping into the system design. We present an approach to multi-view modelling which systematically integrates the twogenerally accepted complexity reduction techniques of hierarchical decomposition and multiviewing. While these techniques are common practice in many modern design tools, the approach presented in this paper defines how the inter-view relationships can be used to tightly interweave the views' hierarchies. This provides a good basis for an information sharing environment enabling model based, multi-disciplinary development. A small case study is used to exemplify how the proposed method simplifies the process of allocating system functions to a hardware architecture in a truck.© 2005 by Jad El-khoury, Ola Redell and Martin Törngren. Published and used by INCOSE with permission.

  • 317.
    Ellervee, Peeter
    et al.
    KTH, Superseded Departments (pre-2005), Electronic Systems Design.
    Öberg, Johnny
    SpaceBall-1G: Instruction Set and Cache Modelling1995Report (Other academic)
  • 318.
    Ellervee, Peeter
    et al.
    KTH, Superseded Departments (pre-2005), Electronic Systems Design.
    Öberg, Johnny
    Tenhunen, Hannu
    Partitioning of a 1 GIPS Revolver Processor Architecture into a Tiled GaAs VLSI Implementation1995Conference paper (Refereed)
  • 319.
    Elspas, Philip
    KTH, School of Electrical Engineering (EES), Network and Systems engineering.
    Predicting Service Metrics of Cloud Applications with Neural Networks2017Report (Other academic)
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  • 320. Engquist, Björn
    et al.
    Runborg, Olof
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Numerical Analysis, NA. KTH, Centres, SeRC - Swedish e-Science Research Centre.
    Tsai, Y. -HR.
    Preface2012In: Workshop on Numerical Analysis and Multiscale Computations, 2009, Springer Verlag , 2012Conference paper (Refereed)
  • 321.
    Engström, Magnus
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Digitala hållbarhetsverktyg – Åsikter, attityder och framtidsutsikter: En undersökning kring användningen av mjukvara som stöd i hållbarhetsarbetet bland företag2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Ökade krav på hållbarhet bland företag tillsammans med en allt mer komplex leverantörskedja medför ett ökat behov av nya verktyg. Ett sådant verktyg är mjukvara specifikt utvecklad för att hantera hållbarhet. I denna undersökning inkluderas små, medelstora och stora företaget och syftet har varit att ta reda på hur dessa nya digitala verktyg kan förbättra företagens hållbarhet samt utreda vad företagen har för inställning till användning av mjukvara för hållbarhet. Undersökningen bestod av en litteraturstudie, enkätundersökning samt intervjuer. Litteraturstudien genomfördes för att få en överblick över den nuvarande situationen på marknaden för hållbarhetsmjukvara, samt för att få en djupare förståelse för ämnet. Enkätundersökningens syfte var att få en överblick över företagens inställning och attityd kring hållbarhetsmjukvara. Intervjuerna genomfördes sist för att få en djupare förståelse och insikt i företagens arbetsmetoder och deras inställning till användningen av digitala verktyg som stöd i hållbarhetsarbetet. Resultatet av undersökningen visar att företagen överlag är positivt inställda till att användningen av hållbarhetsmjukvara. De verktyg som finns tillgängliga i dagsläget är ofta inte anpassade till arbetet med hållbarhet men används ändå. Vidare visar denna undersökning att företagen kan tänka sig att börja använda hållbarhetsmjukvara, så länge mjukvaruleverantörerna kan uppvisa någon form av nytta med att börja använda dessa verktyg. Nytta i det här fallet kan innebära allt från sparad arbetstid till underlättande av kommunikation. Företagen är försiktigt positiva och inser själva att nya sätt att jobba är nödvändigt för att hänga med i utvecklingen på hållbarhetsområdet där kraven hela tiden ökar. Det främsta användningsområdet för hållbarhetsmjukvara är i dagsläget insamling och sammanställning av hållbarhetsdata och den viktigaste egenskapen hos hållbarhetsmjukvara är enligt företagen användarvänlighet. Slutligen konstateras att marknaden för hållbarhetsmjukvara väntas växa. Det gäller därför för mjukvaruleverantörer att erbjuda en produkt som underlättar företagens hållbarhetsarbete. Företagen är villiga att undersöka införandet av hållbarhetsmjukvara, så länge implementeringen kan motiveras med någon form av affärsnytta. 

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  • 322.
    Ennajib, Karim
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Liang, Tommy
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Detektering av fusk vid användning av AI: En studie av detektionsmetoder2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report analyzes and tests various methods aimed at distinguishinghuman-generated solutions to tasks and texts from those generated by artificialintelligence. Recently the use of artificial intelligence has seen a significantincrease, especially among students. The purpose of this study is to determinewhether it is currently possible to detect if a college student in electricalengineering is using AI to cheat. In this report, solutions to tasks and textsgenerated by the program ChatGPT are tested using a general methodology andexternal AI-based tools. The research covers the areas of mathematics,programming and written text. The results of the investigation suggest that it is notpossible to detect cheating with the help of an AI in the subjects of mathematicsand programming. In the case of text, cheating by using an AI can be detected tosome extent.

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    Detektering av fusk vid användning av AI
  • 323.
    Enqvist, Per
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Svensson, Göran
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    A Marginal Allocation Approach to Resource Management for a System of Multiclass Multiserver Queues Using Abandonment and CVaR QoS Measures2019In: 7th International Conference on Operations Research and Enterprise Systems, ICORES 2018, Springer Verlag , 2019, p. 119-133Conference paper (Refereed)
    Abstract [en]

    A class of resource allocation problems is considered where some quality of service measure is set against the agent related costs. Three multiobjective minimization problems are posed, one for a system of Erlang-C queues and two for systems of Erlang-A queues. In the case of the Erlang-C systems we introduce a quality of service measure based on the Conditional Value-at-Risk with waiting time as the loss function. This is a risk coherent measure and is well established in the field of finance. An algebraic proof ensures that this quality of service measure is integer convex in the number of servers. In the case of the Erlang-A systems we introduce two different quality of service measures. The first is a weighted sum of fractions of abandoning customers and the second is Conditional Value-at-Risk, with the waiting time in queue for a customer conditioned on eventually receiving service. Finally, numerical experiments on the two system types with the given quality of service measures, are presented and the optimal solutions are compared.

  • 324.
    Enqvist, Per
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Svensson, Göran
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    A state dependent chat system model2019In: ICORES 2019 - Proceedings of the 8th International Conference on Operations Research and Enterprise Systems, SciTePress , 2019, p. 121-132Conference paper (Refereed)
    Abstract [en]

    The main purpose of this paper is to introduce a model of a chat based communication system, as well as developing the necessary tools to enable resource optimization with regards to a measure of the service quality. The system is modeled by a Markov process in continuous time and with a countable state space. The construction of the intensity matrix corresponding to this system is outlined and proofs of a stationary state distribution and an efficient way of calculating it are introduced. A numerical example for system optimization when the service measure is the average sojourn time is included as well as a heuristic algorithm for quicker solution generation. 

  • 325.
    Ericson, Anja
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Haglund, Linn
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Mobility Management - smart och hållbart eller ett spel för gallerierna?: Boendes upplevelser, attityder & beteenden i förhållande till mjuka åtgärder i bostadsprojekt med låga parkeringstal2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In contemporary society, a common aim is to increase sustainable travel in order to foster the ecological environment. This is to be made possible by a transformation in travel modes from car to public transport, walking and cycling. Stockholm, which is the city focused on in this study, is currently growing. This further results in increased demands for infrastructure and housing. Municipalities have started to allow real estate actors to include Mobility Management measures in housing development in exchange for lower parking demands, to further support the modal change. Such measures can for example be defined as memberships in carpools, cycle pools, information and knowledge exchange. Thus, such implementations are stated as useful methods, however, the effects are poorly assessed and are difficult to measure. According to this, the purpose of this study is to examine relationships between residents' attitudes and behaviours and Mobility Management measures in newly developed housing projects with low parking numbers. The three projects of Flora, Nor and Kavringen were selected, due to the possibility of comparison. The focus has chosen to be on residents' perspectives, as they are the definitive users of the measures. Theories of attitudes and habits have further been used as a framework in order to obtain a greater understanding of the residents' relationship to the measures and to sustainable travel in general. The results, which are based on surveys and interviews, show a variation in attitudes towards sustainable travel and travel modes among the users between and within the study objects. Many appear to treasure sustainable traveling in order to foster the environment and according to this, they seem to have advantageous attitudes towards such travel modes. More residents seem to also travel with sustainable modes. However, other factors than supporting the environment seem to steer respondents in their modal choices. Several residents do also value car use to a high extent. With regards to the Mobility Management measures, the average usage has appeared to be low. This seems to be a result of a shortage in information, logistics, accessibility and in addition, the measures appear to not be competitive enough to respond to the users' needs. Based on demographic factors, time, economy, comfort, accessibility to service and work and the Covid 19 pandemic, such aspects seem to affect users' modal choices more than for them to travel in a way to support the ecological environment.

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  • 326. Eriksson, Y.
    et al.
    Gärdenfors, Dan
    KTH, School of Industrial Engineering and Management (ITM), Centres, Stockholm International Toy Research Center, SITREC.
    Computer games for children with visual impairments2005In: Journal of Endocrine Genetics, ISSN 1565-012X, Vol. 4, no 3, p. 161-167Article in journal (Refereed)
    Abstract [en]

    The Swedish Library of Talking Books and Braille (TPB) published web-based computer games for children with different kinds of visual impairments. As the target groups have very different needs, when it comes to the use of graphics and sound, TPB have developed two kinds of games. Image-based games aim to encourage children with partial sight to practice recognizing visual objects, whereas sound-based games also intend to be accessible without relying on vision. Based on the results of two pilot studies, this paper discusses central design issues of the graphical and sound-based interfaces for this type of application.

  • 327.
    Eryonucu, Cihan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS.
    Papadimitratos, Panagiotis
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS.
    Sybil-Based Attacks on Google Maps or How to Forge the Image of City Life2022In: WiSec 2022 - Proceedings of the 15th ACM Conference on Security and Privacy in Wireless and Mobile Networks, New York: Association for Computing Machinery (ACM), 2022, p. 73-84Conference paper (Refereed)
    Abstract [en]

    Location-based services (LBS) increasingly rely on participatory or crowd-sensed data: users voluntarily contribute data about their whereabouts and points of interest (POIs) and allow the LBS to capture the dynamically changing environment, e.g., how crowded specific places, streets, or public transportation are. Popular LBS applications do not offer strong security, less so for their participatory sensing (PS) and data contribution part. Openness favors participation and increases data, but it also makes attacks easier. Sporadic misbehavior incidents and the presumed user honesty should not be reassuring: an attacker could exploit the PS components and submit a large volume of forged data to dominate the PS-collected LBS data, locally or at a large scale. Individuals, organizations, or entire areas could be targeted, e.g., having customers diverted or causing public transportation routes or roads to appear congested. The lingering open question is whether such attacks can be perpetrated against well-established popular LBS with PS components. This paper affirms this: we investigate Google Maps, the single most popular application in this domain, and show a range of effective and scalable attacks based on very modest adversarial assumptions. We reverse-engineer the data submission process and automate attacks that craft and submit false data in volume and a targeted fashion. We collect evidence that our attacks work on POI crowdedness, traffic congestion levels, and public transportation crowdedness with extreme caution. We responsibly disclosed the attacks to Google, acknowledged them and awarded recognition. The attack methodology carries over to other LBS applications but, most importantly, raises awareness and motivates countermeasures, which we also outline here, for stronger LBS and PS security overall.

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    Sybil_attacks_on_Google_Maps
  • 328.
    Eshghie, Mojtaba
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Artho, Cyrille
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Gurov, Dilian
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Dynamic Vulnerability Detection on Smart Contracts Using Machine Learning2021In: Proceedings Of Evaluation And Assessment In Software Engineering (EASE 2021), Association for Computing Machinery (ACM) , 2021, p. 305-312Conference paper (Refereed)
    Abstract [en]

    In this work we propose Dynamit, a monitoring framework to detect reentrancy vulnerabilities in Ethereum smart contracts. The novelty of our framework is that it relies only on transaction metadata and balance data from the blockchain system; our approach requires no domain knowledge, code instrumentation, or special execution environment. Dynamit extracts features from transaction data and uses a machine learning model to classify transactions as benign or harmful. Therefore, not only can we find the contracts that are vulnerable to reentrancy attacks, but we also get an execution trace that reproduces the attack. Using a random forest classifier, our model achieved more than 90 percent accuracy on 105 transactions, showing the potential of our technique.

  • 329. Eslami Kiasari, Abbas
    et al.
    Sarbazi-Azad, Hamid
    Ould-Khaoua, Mohamed
    An Accurate Mathematical Performance Model of Adaptive Routing in the Star Graph2008In: Future generations computer systems, ISSN 0167-739X, E-ISSN 1872-7115, Vol. 24, no 6, p. 461-474Article in journal (Refereed)
    Abstract [en]

    Analytical modelling is indeed the most cost-effective method to evaluate the performance of a system. Several analytical models have been proposed in the literature for different interconnection network systems. This paper proposes an accurate analytical model to predict message latency in wormhole-switched star graphs with fully adaptive routing. Although the focus of this research is on the star graph but the approach used for modelling can be, however, used for modelling some other regular and irregular interconnection networks. The results obtained from simulation experiments confirm that the proposed model exhibits a good accuracy for various network sizes and under different operating conditions.

  • 330.
    Etemadi, Khashayar
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Tarighat, Niloofar
    Sharif Univ Technol, Tehran, Iran..
    Yadav, Siddharth
    Indraprastha Inst Informat Technol Delhi, Delhi, India..
    Martinez, Matias
    Univ Polytech Hauts De France, Valenciennes, France..
    Monperrus, Martin
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Estimating the potential of program repair search spaces with commit analysis2022In: Journal of Systems and Software, ISSN 0164-1212, E-ISSN 1873-1228, Vol. 188, article id 111263Article in journal (Refereed)
    Abstract [en]

    The most natural method for evaluating program repair systems is to run them on bug datasets, such as Defects4J. Yet, using this evaluation technique on arbitrary real-world programs requires heavy configuration. In this paper, we propose a purely static method to evaluate the potential of the search space of repair approaches. This new method enables researchers and practitioners to encode the search spaces of repair approaches and select potentially useful ones without struggling with tool configuration and execution. We encode the search spaces by specifying the repair strategies they employ. Next, we use the specifications to check whether past commits lie in repair search spaces. For a repair approach, including many human-written past commits in its search space indicates its potential to generate useful patches. We implement our evaluation method in LIGHTER. LIGHTER gets a Git repository and outputs a list of commits whose source code changes lie in repair search spaces. We run LIGHTER on 55,309 commits from the history of 72 Github repositories with and show that LIGHTER's precision and recall are 77% and 92%, respectively. Overall, our experiments show that our novel method is both lightweight and effective to study the search space of program repair approaches.

  • 331.
    Fan, Yiming
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Presentation Slides Recommender System Design2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Using presentation software such as PowerPoint or Keynote to sup- port lectures and presentations has become ubiquitous in both academia and industry. However, designing the visuals of presentation slides is a time-consuming and laborious task; repetitive steps are required for selecting templates, organizing objects, and optimizing layouts. To al- leviate these laborious works and to allow users to focus on preparing the contents of presentations, we present SmartPPT, a framework that supports the automatic generation of presentation slides from textual outline. We built a Recommender System model inside the framework that could pick up slide templates for input textual outline. To test its functionality and efficiency, two sets of user study procedures were conducted and shown that SmartPPT is time efficient in generating slides and it outperforms in user satisfaction when compared to user- handcrafted slides and the baseline condition, which was PowerPoint suggested templates.

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  • 332.
    Fang, Huan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Brorsson, Mats
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Scalable directory architecture for distributed shared memory chip multiprocessors2008In: Proceedings of the 1st Swedish Workshop on Multi-core Computing, 2008, p. 73-81Conference paper (Refereed)
    Abstract [en]

    Traditional Directory-based cache coherence protocol is far from optimal for large-scale cache coherent shared memory multiprocessors due to the increasing latency to access directories stored in DRAM memory. Instead of keeping directories in main memory, we consider distributing the directory together with L2 cache across all nodes on a Chip Multiprocessor. Each node contains a processing unit, a private L1 cache, a slice of L2 cache, memory controller and a router. Both L2 cache and memories are distributed shared and interleaved by a subset of memory address bits. All nodes are interconnected through a low latency two dimensional Mesh network.

    Directory, as a split component as L2 cache, only stores sharing information for blocks while L2 cache only stores data blocks exclusive with L1 cache. Shared L2 cache can increase total effective cache capacity on chip, but also increase the miss latency when data is on a remote node. Being different from Directory Cache structure, our proposal totally removes the directory from memory which saves memory space and reduces access latency. Compared to L2 cache which combines directory information internally, our split L2 cache structure saves over 88% cache space while having achieved similar performance.

  • 333.
    Faradj, Rasti
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Habtu, Simon
    KTH, School of Information and Communication Technology (ICT).
    Modell för att utvärdera skärmhanteringsmetoder: Med ett fokus på hållbar utveckling hos stora organisationer2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Forward-thinking technology has led to the situation today where computers and belonging computer screens are a part of everyday life. They are used in many different cases, as well as government agencies and organizations to accomplish various assignments. Management of these computer screens are done with the help of screen management methods that put them to sleep mode. Distinguishing these management methods based on their characteristics is difficult and presently there is no custom evaluation model for this.

     

    This study provides an evaluation model that is able to choose an optimal screen management method by applying it. The purpose of choosing an optimal screen management method is to simultaneously decrease the power consumption of computer screens. The study is of qualitative nature with an inductive approach.  This led to the production of an evaluation model "MUSk" (Model for Evaluating Screen management methods). It was created in relation with interviews and litterature studies that were used to collect data. To verify the legitimacy of the MUSk-model it was evaluated. Screen management methods evaluated by applying MUSk-model to then give an opinion on the display management method that was most optimal. The MUSk-model is presented as a result of this study and can be applied to distinguish screen management methods. Based on the elements of the MUSk-model it was determined that Windows Power Management was the most optimal screen management method.

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  • 334.
    Farhadi, Hamed
    et al.
    University of Tehran, School of electrical and Computer Engineering.
    Lahouti, Farshad
    University of Tehran, School of electrical and Computer Engineering.
    Ahmadi Brooghani, Seyed Yousef
    University of Birjand, Faculty of Engineering, Mechanical Engineering Department.
    Thermal Effects on the Analog Decoder Performance2007In: 6th AnalogDecoding Workshop, Montreal, QC Canada, 2007Conference paper (Refereed)
    Download (pdf)
    summary
  • 335.
    Farshin, Alireza
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS, Network Systems Laboratory (NS Lab).
    Realizing Low-Latency Packet Processing on Multi-Hundred-Gigabit-Per-Second Commodity Hardware: Exploit Caching to Improve Performance2023Doctoral thesis, monograph (Other academic)
    Abstract [en]

    By virtue of the recent technological developments in cloud computing, more applications are deployed in the cloud. Among these modern cloud-based applications, many societal applications require bounded and predictable low-latency responses. However, the current cloud infrastructure is unsuitable for these applications since it cannot satisfy these requirements due to many limitations in both hardware and software.

    This doctoral dissertation describes our attempts to reduce the latency of Internet services by carefully studying the multi-hundred-gigabit-per-second commodity hardware, optimizing it, and improving its performance. The main focus is to improve the performance of packet processing done by the network functions deployed on commodity hardware, known as network functions virtualization (NFV), which is one of the significant sources of latency for Internet services.

    The first contribution of this dissertation takes a step toward optimizing the cache performance of time-critical NFV service chains. By doing so, we reduce the tail latencies of such systems running at 100 Gbps. This is an important achievement as it increases the probability of realizing bounded and predictable latency for Internet services.

    The second contribution of this dissertation performs whole-stack optimizations on software-based network functions deployed on top of modular packet processing frameworks to further enhance the effectiveness of cache memories. We build a system to efficiently handle metadata and produce a customized binary of NFVservice chains. Our system improves both throughput & latency of per-core hundred-gigabit-per-second packet processing on commodity hardware.

    The third contribution of this dissertation studies the efficiency of I/O security solutions provided by commodity hardware at multi-hundred-gigabit-per-second rates. We characterize the performance of IOMMU & IOTLB (i.e., I/O virtual address translation cache) at 200 Gbps and explore the possible opportunities to mitigate its performance overheads in the Linux kernel.

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  • 336.
    Farshin, Alireza
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS, Network Systems Laboratory (NS Lab).
    Rizzo, Luigi
    Google, Mountain View, CA, United States.
    Elmeleegy, Khaled
    Google, Mountain View, CA, United States.
    Kostic, Dejan
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Communication Systems, CoS, Network Systems Laboratory (NS Lab). KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS.
    Overcoming the IOTLB wall for multi-100-Gbps Linux-based networking2023In: PeerJ Computer Science, E-ISSN 2376-5992, Vol. 9, p. e1385-, article id cs-1385Article in journal (Refereed)
    Abstract [en]

    This article explores opportunities to mitigate the performance impact of IOMMU on high-speed network traffic, as used in the Linux kernel. We first characterize IOTLB behavior and its effects on recent Intel Xeon Scalable & AMD EPYC processors at 200 Gbps, by analyzing the impact of different factors contributing to IOTLB misses and causing throughput drop (up to 20% compared to the no-IOMMU case in our experiments). Secondly, we discuss and analyze possible mitigations, including proposals and evaluation of a practical hugepage-aware memory allocator for the network device drivers to employ hugepage IOTLB entries in the Linux kernel. Our evaluation shows that using hugepage-backed buffers can completely recover the throughput drop introduced by IOMMU. Moreover, we formulate a set of guidelines that enable network developers to tune their systems to avoid the “IOTLB wall”, i.e., the point where excessive IOTLB misses cause throughput drop. Our takeaways signify the importance of having a call to arms to rethink Linux-based I/O management at higher data rates.

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    iotlb-peerj23
  • 337.
    Farshin, Alireza
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Communication Systems, CoS, Network Systems Laboratory (NS Lab). KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS.
    Roozbeh, Amir
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Communication Systems, CoS, Network Systems Laboratory (NS Lab). KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS. Ericsson Research.
    Schulte, Christian
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS.
    Maguire Jr., Gerald Q.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS.
    Kostic, Dejan
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Communication Systems, CoS, Network Systems Laboratory (NS Lab). KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS.
    Scheduling - A Secret Sauce For Resource DisaggregationManuscript (preprint) (Other academic)
    Abstract [en]

    This technical report describes the design & implementation of a constraint-based framework for scheduling & resource allocation in a disaggregated data center (DDC) where we build logical servers from disaggregated resources. We show that an Service LevelObjective (SLO)-aware constraint-based solver could improve a data center’s resource utilization by finding better solutions based on provided workload characteristics.

    Download full text (pdf)
    fulltext
  • 338.
    Fei, Chao
    et al.
    Zhejiang Univ, Ningbo Res Inst, Ningbo 315100, Peoples R China.;Zhejiang Univ, Coll Opt Sci & Engn, Natl Engn Res Ctr Opt Instruments, Ctr Opt & Electromagnet Res,State Key Lab Modern, Hangzhou 310058, Peoples R China..
    Chen, Ruilin
    Zhejiang Univ, Coll Opt Sci & Engn, Natl Engn Res Ctr Opt Instruments, Ctr Opt & Electromagnet Res,State Key Lab Modern, Hangzhou 310058, Peoples R China..
    Du, Ji
    Zhejiang Univ, Coll Opt Sci & Engn, Natl Engn Res Ctr Opt Instruments, Ctr Opt & Electromagnet Res,State Key Lab Modern, Hangzhou 310058, Peoples R China..
    Wang, Yuan
    Zhejiang Univ, Coll Opt Sci & Engn, Natl Engn Res Ctr Opt Instruments, Ctr Opt & Electromagnet Res,State Key Lab Modern, Hangzhou 310058, Peoples R China..
    Tian, Jiahan
    Zhejiang Univ, Coll Opt Sci & Engn, Natl Engn Res Ctr Opt Instruments, Ctr Opt & Electromagnet Res,State Key Lab Modern, Hangzhou 310058, Peoples R China..
    Zhang, Guowu
    McGill Univ, Dept Elect & Comp Engn, Montreal, PQ H3A 0E9, Canada..
    Zhang, Junwei
    Sun Yat Sen Univ, Sch Elect & Informat Technol, State Key Lab Optoelect Mat & Technol, Guangzhou 510006, Peoples R China..
    Hong, Xiaojian
    Zhejiang Univ, Ningbo Res Inst, Ningbo 315100, Peoples R China.;Zhejiang Univ, Coll Opt Sci & Engn, Natl Engn Res Ctr Opt Instruments, Ctr Opt & Electromagnet Res,State Key Lab Modern, Hangzhou 310058, Peoples R China..
    He, Sailing
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electromagnetic Engineering. Zhejiang Univ, Ningbo Res Inst, Ningbo 315100, Peoples R China.;Zhejiang Univ, Coll Opt Sci & Engn, Natl Engn Res Ctr Opt Instruments, Ctr Opt & Electromagnet Res,State Key Lab Modern, Hangzhou 310058, Peoples R China..
    Underwater wireless optical communication utilizing low-complexity sparse pruned-term-based nonlinear decision-feedback equalization2022In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 61, no 22, p. 6534-6543Article in journal (Refereed)
    Abstract [en]

    The nonlinearity of the light-emitting diode (LED) in underwater wireless optical communication (UWOC) systems is considered the one major limiting factor that degrades the system's performance. Volterra series-based nonlinear equalization is widely employed to mitigate such nonlinearity in communication systems. However, the conventional Volterra series-based model is of high complexity, especially for the nonlinearity of higher-order terms or longer memory lengths. In this paper, by pruning away some negligible beating terms and adaptively picking out some of the dominant terms while discarding the trivial ones, we propose and experimentally demonstrate a sparse pruned-term-based nonlinear decision-feedback equalization (SPT-NDFE) scheme for the LED-based UWOC system with an inappreciable performance degradation as compared to systems without the pruning strategy. Meanwhile, by replacing the self/cross beating terms with the terms formed by the absolute operation of a sum of two input samples instead of the product operation terms, a sparse pruned-term-based absolute operation nonlinear decision-feedback equalization (SPT-ANDFE) scheme is also introduced to further reduce complexity. The experimental results show that the SPT-NDFE scheme exhibits comparable performance as compared to the conventional NDFE (nonlinear decision-feedback equalization) scheme with lower complexity (the nonlinear coefficients are reduced by 63.63% as compared to the conventional NDFE scheme). While the SPT-ANDFE scheme yields suboptimal performance with further reduced complexity at the expense of a slight performance degradation, the robustness of the proposed schemes in different turbidity waters is experimentally verified. The proposed channel equalization schemes with low complexity and high performance are promising for power/energy-sensitive UWOC systems.

  • 339.
    Fernaeus, Ylva
    KTH, School of Electrical Engineering and Computer Science (EECS).
    How do you design for the joy of movement?2012In: Plei-Plei! / [ed] Fernaeus, Y., Holopainen, J., Höök, K., Ivarsson, K., Karlsson, A., Lindley, S., & Norlin, C., Stockholm: PPP Company Ltd , 2012, p. 8-15Chapter in book (Other academic)
    Abstract [en]

    The work in this book was conducted at an exciting point in time when the whole field of Human-Computer Interaction shifted its focus away from settings in which people would sit more or less still in front of static computers, to instead start exploring how to make good use of all the added possibilities of technologies that can be moved around. At the same time, researchers became increasingly interested in aspects of experience and enjoyment in the use of technology. As discussed in the introduction, notions such and play and learning, work and leisure, casual and serious technology use, are sometimes presented as conceptual dichotomies that may be difficult to combine. However, to many people, such distinctions are not meaningful, since practices and technologies – especially mobile ones – travel between the different social spheres of our lives, accompanying them wherever they go. Therefore,

    addressing aspects of leisure, pleasure and play is a relevant challenge for most interaction designers. In many cases, mobility and enjoyment seems very tightly intertwined, and in this chapter I will discuss different ways that this has become manifested in the illustrated pages of this book.

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  • 340.
    Fernaeus, Ylva
    KTH, School of Computer Science and Communication (CSC), Human - Computer Interaction, MDI.
    Let's Make a Digital Patchwork: Designing for Children’s Creative Play with Programming Materials2007Doctoral thesis, comprehensive summary (Other academic)
  • 341.
    Fernaeus, Ylva
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Human Centered Technology, Media Technology and Interaction Design, MID.
    Lindegren, Andreas
    KTH, School of Electrical Engineering and Computer Science (EECS), Human Centered Technology, Media Technology and Interaction Design, MID.
    Celebration of Finitude as a Post-Industrial Aesthetics of Interaction2023In: Ninth Computing within Limits 2023, 2023Conference paper (Refereed)
    Abstract [en]

    This paper elaborates on design visions for computing, by attending to the values expressed in ideals around post-industrial ways of living. Such ideals highlight finitude not only as a challenge to overcome, but as an aesthetic quality, captured by notions of preciousness. We discuss three themes: to embrace possibilities within limits, to resist fantasies of unlimited power, and welcoming complexity as an inherent feature of the living.

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    Fernaeus_Lindegren_Limits_23
  • 342.
    Ferreira, Pedro
    KTH, School of Computer Science and Communication (CSC), Media Technology and Interaction Design, MID.
    Play as Freedom: Implications for ICT4D2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Information and Communication Tech nologies for Development (ICT4D) deals with understanding the relationship between modern technology use and social and economic development. While play may not appear as an immediate concern to the field, a recent body of work has emerged questioning the role of play in ICT4D and the reasons behind its apparent dismissal. Some have even argued that aspects of pleasure and enjoyment get only marginal treatment within academic studies of technology more generally. In ICT4D however, concerns over lack of resources and a sense of urgency in addressing more pressing needs, creates in itself an added set of boundaries which may further restrict both the playful activities themselves, as well as their recognition in academic work. In this work I will revisit the work done in ICT4D with regards to play in order to frame the contributions that lie herein.

    I will revisit in this work two distinct projects I have worked in during my PhD: the first an ethnographic fieldwork in Rah Island, Vanuatu, where I documented the first weeks of mobile phone usage; the second project took place during an internship at Microsoft Research India, where I participated in the design, development and deployment of KrishiPustak, a social networking system for low-literate users in rural areas around Hunsur district. To understand and unpack my reflections around play in both these projects, I propose a framing of play as a freedom, inspired by Amartya Sen’s work, discussing three of its roles: its instrumental role, in that play serves as a vehicle for achieving secondary outcomes, such as with educational games; its constructive role, in that play in itself unleashes an attitude of deliberation over the boundaries that surround play, questioning and re shaping those boundaries. I draw on Christena Nippert-Eng’s notion of boundary play and boundary work to explore the contributions that play has in constructively determining and reshaping values, goals and priorities in ICT4D work.

    But most importantly, this thesis emphasizes play’s third role, its intrinsic role to be the starting point of any understanding: i.e. play is important because people have reasons to value play. This urges us to consider the intrinsic importance, not only to observe play as it unfolds, but to actively design for, and open up opportunities for play to occur.

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    Thesis
  • 343.
    Fetahi, Wuhib
    et al.
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Dam, Mads
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Stadler, Rolf
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Alexander, Clemm
    Cisco Systems, San Jose, CA USA.
    Robust Monitoring of Network-wide Aggregates through Gossiping2009In: IEEE Transactions on Network and Service Management, ISSN 1932-4537, E-ISSN 1932-4537, Vol. 6, no 2, p. 95-109Article in journal (Refereed)
    Abstract [en]

    We investigate the use of gossip protocols for continuousmonitoring of network-wide aggregates under crash failures.Aggregates are computed from local management variablesusing functions such as SUM, MAX, or AVERAGE. For this typeof aggregation, crash failures offer a particular challenge dueto the problem of mass loss, namely, how to correctly accountfor contributions from nodes that have failed. In this paper wegive a partial solution. We present G-GAP, a gossip protocolfor continuous monitoring of aggregates, which is robust againstfailures that are discontiguous in the sense that neighboringnodes do not fail within a short period of each other. We giveformal proofs of correctness and convergence, and we evaluatethe protocol through simulation using real traces. The simulationresults suggest that the design goals for this protocol have beenmet. For instance, the tradeoff between estimation accuracyand protocol overhead can be controlled, and a high estimationaccuracy (below some 5% error in our measurements) is achievedby the protocol, even for large networks and frequent nodefailures. Further, we perform a comparative assessment of GGAPagainst a tree-based aggregation protocol using simulation.Surprisingly, we find that the tree-based aggregation protocolconsistently outperforms the gossip protocol for comparativeoverhead, both in terms of accuracy and robustness.

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    fulltext
  • 344.
    Filipovikj, Predrag
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Causevic, Aida
    Mälardalen Univ, Västerås, Sweden..
    Lisova, Elena
    Mälardalen Univ, Västerås, Sweden..
    Service Realizability Check as a Technique to Support a Service Security Assurance Case2020In: 2020 ieee international conference on industrial technology (icit), IEEE , 2020, p. 973-980Conference paper (Refereed)
    Abstract [en]

    Advances in cloud computing make cloud services as an appealing solution for enabling services flexibility and availability on demand to accommodate users' needs. The terms and the guarantees of service provision are negotiated and then stated in a Service Level Agreement (SLA). To facilitate a wider acceptance of such services, beside the standard properties, security has to be taken into consideration as well. One way to facilitate this is to provide a corresponding security assurance case. For that purpose, in this work we propose to split the security service assessment between an independent third party and a service user, where the former assess a security assurance case and the latter negotiates particular security solutions implemented for a service. For the systematic part of the security process that is independently assessed, in this paper we focus on the formal realizability check of service constraints expressed within an SLA. To enable this, we formalize the check at both service design-, and run-time, needed due to frequent updates required to maintain an agreed security level. The formalization is tailored for the SLAC language specifically, which is extended to cover a proposed set of security objectives. Moreover, we use an example of an SLA expressed in terms of SLAC language, which includes security guarantees to illustrate the approach.

  • 345.
    Foerster, Klaus Tycho
    et al.
    TU Dortmund, Dortmund, Germany.
    Marette, Thibault
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Neumann, Stefan
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Theoretical Computer Science, TCS.
    Plant, Claudia
    Faculty of Computer Science and ds:Univie, University of Vienna, Vienna, Austria.
    Sadikaj, Ylli
    Faculty of Computer Science and UniVie Doctoral School Computer Science, University of Vienna, Vienna, Austria.
    Schmid, Stefan
    TU Berlin, Berlin, Germany.
    Velaj, Yllka
    Faculty of Computer Science, University of Vienna, Vienna, Austria.
    Analyzing the Communication Clusters in Datacenters2023In: ACM Web Conference 2023: Proceedings of the World Wide Web Conference, WWW 2023, Association for Computing Machinery (ACM) , 2023, p. 3022-3032Conference paper (Refereed)
    Abstract [en]

    Datacenter networks have become a critical infrastructure of our digital society and over the last years, great efforts have been made to better understand the communication patterns inside datacenters. In particular, existing empirical studies showed that datacenter traffic typically features much temporal and spatial structure, and that at any given time, some communication pairs interact much more frequently than others. This paper generalizes this study to communication groups and analyzes how clustered the datacenter traffic is, and how stable these clusters are over time. To this end, we propose a methodology which revolves around a biclustering approach, allowing us to identify groups of racks and servers which communicate frequently over the network. In particular, we consider communication patterns occurring in three different Facebook datacenters: a Web cluster consisting of web servers serving web traffic, a Database cluster which mainly consists of MySQL servers, and a Hadoop cluster. Interestingly, we find that in all three clusters, small groups of racks and servers can produce a large fraction of the network traffic, and we can determine these groups even when considering short snapshots of network traffic. We also show empirically that these clusters are fairly stable across time. Our insights on the size and stability of communication clusters hence uncover an interesting potential for resource optimizations in datacenter infrastructures.

  • 346.
    Foerster, Klaus-Tycho
    et al.
    Univ Vienna, Vienna, Austria..
    Parham, Mahmoud
    Univ Vienna, Vienna, Austria..
    Chiesa, Marco
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Schmid, Stefan
    Univ Vienna, Vienna, Austria..
    TI-MFA: Keep Calm and Reroute Segments Fast2018In: IEEE INFOCOM 2018 - IEEE CONFERENCE ON COMPUTER COMMUNICATIONS WORKSHOPS (INFOCOM WKSHPS), IEEE , 2018, p. 415-420Conference paper (Refereed)
    Abstract [en]

    Segment Routing (SR) promises to provide scalable and fine-grained traffic engineering. However, little is known today on how to implement resilient routing in SR, i.e., routes which tolerate one or even multiple failures. This paper initiates the theoretical study of static fast failover mechanisms which do not depend on reconvergence and hence support a very fast reaction to failures. We introduce formal models and identify fundamental tradeoffs on what can and cannot be achieved in terms of static resilient routing. In particular, we identify an inherent price in terms of performance if routing paths need to be resilient, even in the absence of failures. Our main contribution is a first algorithm which is resilient even to multiple failures and which comes with provable resiliency and performance guarantees. We complement our formal analysis with simulations on real topologies, which show the benefits of our approach over existing algorithms.

  • 347.
    Forte, Paolo
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Predicting Service Metrics from Device and Network Statistics2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    For an IT company that provides a service over the Internet like Facebook or Spotify, it is very important to provide a high quality of service; however, predicting the quality of service is generally a hard task. The goal of this thesis is to investigate whether an approach that makes use of statistical learning to predict the quality of service can obtain accurate predictions for a Voldemort key-value store [1] in presence of dynamic load patterns and network statistics. The approach follows the idea that the service-level metrics associated with the quality of service can be estimated from serverside statistical observations, like device and network statistics. The advantage of the approach analysed in this thesis is that it can virtually work with any kind of service, since it is based only on device and network statistics, which are unaware of the type of service provided.

    The approach is structured as follows. During the service operations, a large amount of device statistics from the Linux kernel of the operating system (e.g. cpu usage level, disk activity, interrupts rate) and some basic end-to-end network statistics (e.g. average round-trip-time, packet loss rate) are periodically collected on the service platform. At the same time,

    some service-level metrics (e.g. average reading time, average writing time, etc.) are collected on the client machine as indicators of the store’s quality of service. To emulate network statistics, such as dynamic delay and packet loss, all the traffic is redirected to flow through a network emulator. Then, different types of statistical learning methods, based on linear and tree-based regression algorithms, are applied to the data collections to obtain a learning model able to accurately predict the service-level metrics from the device and network statistics.

    The results, obtained for different traffic scenarios and configurations, show that the thesis’ approach can find learning models that can accurately predict the service-level metrics for a single-node store with error rates lower than 20% (NMAE), even in presence of network impairments.

    Download full text (pdf)
    fulltext
  • 348.
    Fredrik, Nilsson
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Bodin, Arvid
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Ombyggnad av en statisk webbsida till en responsiv2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today ́s society people are working more and more while travelling, which makes them use smartphones and tablets instead of laptops. These screens are usually smaller than a laptop screen. That is why a more dynamic web design has been re- quested in order to fit the screen on the device being used. The static webpage’s width was 1000 pixels and the goal was to fit all the tables and information in the respon- sive version with a width of 320 pixels. Important information also had to be moved to a different page in order to make it more visible. A new CSS-template was imple- mented and several new Java Scripts followed by finer adjustments to the HTML code. Since some information had to be more visible to the user, a new tab was cre- ated in order to fulfill this demand. The new tab contained information about “Net- work Status” only related to the signed in user. After simulating the webpage in Chrome the responsiveness of the page was confirmed on all screen sizes. Sending the webpage asynchronously made the slow pages respond instantly but the total loading time was still slow. To fix this, back-end programming would have been re- quired. The project’s webpage fulfilled all the requirements. 

    Download full text (pdf)
    fulltext
  • 349.
    Gamba, Matteo
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Chmielewski-Anders, Adrian
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Sullivan, Josephine
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Azizpour, Hossein
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Björkman, Mårten
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Are All Linear Regions Created Equal?2022In: Proceedings 25th International Conference on Artificial Intelligence and Statistics, AISTATS 2022 / [ed] Camps-Valls, G Ruiz, FJR Valera, I, ML Research Press , 2022, Vol. 151Conference paper (Refereed)
    Abstract [en]

    The number of linear regions has been studied as a proxy of complexity for ReLU networks. However, the empirical success of network compression techniques like pruning and knowledge distillation, suggest that in the overparameterized setting, linear regions density might fail to capture the effective nonlinearity. In this work, we propose an efficient algorithm for discovering linear regions and use it to investigate the effectiveness of density in capturing the nonlinearity of trained VGGs and ResNets on CIFAR-10 and CIFAR-100. We contrast the results with a more principled nonlinearity measure based on function variation, highlighting the shortcomings of linear regions density. Furthermore, interestingly, our measure of nonlinearity clearly correlates with model-wise deep double descent, connecting reduced test error with reduced nonlinearity, and increased local similarity of linear regions.

  • 350.
    Gammerman, Alexander
    et al.
    Royal Holloway Univ London, Egham, Surrey, England..
    Vovk, Vladimir
    Royal Holloway Univ London, Egham, Surrey, England..
    Boström, Henrik
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Software and Computer systems, SCS.
    Carlsson, Lars
    Stena Line AB, Gothenburg, Sweden..
    Conformal and probabilistic prediction with applications: editorial2019In: Machine Learning, ISSN 0885-6125, E-ISSN 1573-0565, Vol. 108, no 3, p. 379-380Article in journal (Other academic)
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