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  • 1. AAl Abdulsalam, Abdulrahman
    et al.
    Velupillai, Sumithra
    Meystre, Stephane
    UtahBMI at SemEval-2016 Task 12: Extracting Temporal Information from Clinical Text2016Ingår i: Proceedings of the 10th International Workshop on Semantic Evaluation (SemEval-2016), Association for Computational Linguistics , 2016, s. 1256-1262Konferensbidrag (Refereegranskat)
    Abstract [en]

    The 2016 Clinical TempEval continued the 2015 shared task on temporal information extraction with a new evaluation test set. Our team, UtahBMI, participated in all subtasks using machine learning approaches with ClearTK (LIBLINEAR), CRF++ and CRFsuite packages. Our experiments show that CRF-based classifiers yield, in general, higher recall for multi-word spans, while SVM-based classifiers are better at predicting correct attributes of TIMEX3. In addition, we show that an ensemble-based approach for TIMEX3 could yield improved results. Our team achieved competitive results in each subtask with an F1 75.4% for TIMEX3, F1 89.2% for EVENT, F1 84.4% for event relations with document time (DocTimeRel), and F1 51.1% for narrative container (CONTAINS) relations.

  • 2.
    Aalto, Erik
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Learning Playlist Representations for Automatic Playlist Generation2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Spotify is currently the worlds leading music streaming ser-vice. As the leader in music streaming the task of providing listeners with music recommendations is vital for Spotify. Listening to playlists is a popular way of consuming music, but traditional recommender systems tend to fo-cus on suggesting songs, albums or artists rather than pro-viding consumers with playlists generated for their needs.

    This thesis presents a scalable and generalizeable approach to music recommendation that performs song selection for the problem of playlist generation. The approach selects tracks related to a playlist theme by finding the charac-terizing variance for a seed playlist and projects candidate songs into the corresponding subspace. Quantitative re-sults shows that the model outperforms a baseline which is taking the full variance into account. By qualitative results the model is also shown to outperform professionally curated playlists in some cases.

  • 3.
    Aarno, Daniel
    KTH, Skolan för datavetenskap och kommunikation (CSC), Numerisk Analys och Datalogi, NADA.
    Intention recognition in human machine collaborative systems2007Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [sv]

    Robotsystem har använts flitigt under de senaste årtiondena för att skapa automationslösningar i ett flertal områden. De flesta nuvarande automationslösningarna är begränsade av att uppgifterna de kan lösa måste vara repetitiva och förutsägbara. En av anledningarna till detta är att dagens robotsystem saknar förmåga att förstå och resonera om omvärlden. På grund av detta har forskare inom robotik och artificiell intelligens försökt att skapa intelligentare maskiner. Trots att stora framsteg har gjorts då det gäller att skapa robotar som kan fungera och interagera i en mänsklig miljö så finns det för nuvarande inget system som kommer i närheten av den mänskliga förmågan att resonera om omvärlden.

    För att förenkla problemet har vissa forskare föreslagit en alternativ lösning till helt självständiga robotar som verkar i mänskliga miljöer. Alternativet är att kombinera människors och maskiners förmågor. Exempelvis så kan en person verka på en avlägsen plats, som kanske inte är tillgänglig för personen i fråga på grund av olika orsaker, genom att använda fjärrstyrning. Vid fjärrstyrning skickar operatören kommandon till en robot som verkar som en förlängning av operatörens egen kropp.

    Segmentering och identifiering av rörelser skapade av en operatör kan användas för att tillhandahålla korrekt assistans vid fjärrstyrning eller samarbete mellan människa och maskin. Assistansen sker ofta inom ramen för virtuella fixturer där eftergivenheten hos fixturen kan justeras under exekveringen för att tillhandahålla ökad prestanda i form av ökad precision och minskad tid för att utföra uppgiften.

    Den här avhandlingen fokuserar på två aspekter av samarbete mellan människa och maskin. Klassificering av en operatörs rörelser till ett på förhand specificerat tillstånd under en manipuleringsuppgift och assistans under manipuleringsuppgiften baserat på virtuella fixturer. Den specifika tillämpningen som behandlas är manipuleringsuppgifter där en mänsklig operatör styr en robotmanipulator i ett fjärrstyrt eller samarbetande system.

    En metod för att följa förloppet av en uppgift medan den utförs genom att använda virtuella fixturer presenteras. Istället för att följa en på förhand specificerad plan så har operatören möjlighet att undvika oväntade hinder och avvika från modellen. För att möjliggöra detta estimeras kontinuerligt sannolikheten att operatören följer en viss trajektorie (deluppgift). Estimatet används sedan för att justera eftergivenheten hos den virtuella fixturen så att ett beslut om hur rörelsen ska fixeras kan tas medan uppgiften utförs.

    En flerlagers dold Markovmodell (eng. layered hidden Markov model) används för att modellera mänskliga färdigheter. En gestemklassificerare som klassificerar en operatörs rörelser till olika grundläggande handlingsprimitiver, eller gestemer, evalueras. Gestemklassificerarna används sedan i en flerlagers dold Markovmodell för att modellera en simulerad fjärrstyrd manipuleringsuppgift. Klassificeringsprestandan utvärderas med avseende på brus, antalet gestemer, typen på den dolda Markovmodellen och antalet tillgängliga träningssekvenser. Den flerlagers dolda Markovmodellen tillämpas sedan på data från en trajektorieföljningsuppgift i 2D och 3D med en robotmanipulator för att ge både kvalitativa och kvantitativa resultat. Resultaten tyder på att den flerlagers dolda Markovmodellen är väl lämpad för att modellera trajektorieföljningsuppgifter och att den flerlagers dolda Markovmodellen är robust med avseende på felklassificeringar i de underliggande gestemklassificerarna.

  • 4.
    Aarno, Daniel
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP. KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Centrum för Autonoma System, CAS.
    Sommerfeld, Johan
    KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP. KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Centrum för Autonoma System, CAS.
    Kragic, Danica
    KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP. KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Centrum för Autonoma System, CAS.
    Pugeault, Nicolas
    Kalkan, Sinan
    Woergoetter, Florentin
    Krüger, Norbert
    Early reactive grasping with second order 3D feature relations2008Ingår i: Recent Progress In Robotics: Viable Robotic Service To Human / [ed] Lee, S; Suh, IH; Kim, MS, 2008, Vol. 370, s. 91-105Konferensbidrag (Refereegranskat)
    Abstract [en]

    One of the main challenges in the field of robotics is to make robots ubiquitous. To intelligently interact with the world, such robots need to understand the environment and situations around them and react appropriately, they need context-awareness. But how to equip robots with capabilities of gathering and interpreting the necessary information for novel tasks through interaction with the environment and by providing some minimal knowledge in advance? This has been a longterm question and one of the main drives in the field of cognitive system development. The main idea behind the work presented in this paper is that the robot should, like a human infant, learn about objects by interacting with them, forming representations of the objects and their categories that are grounded in its embodiment. For this purpose, we study an early learning of object grasping process where the agent, based on a set of innate reflexes and knowledge about its embodiment. We stress out that this is not the work on grasping, it is a system that interacts with the environment based on relations of 3D visual features generated trough a stereo vision system. We show how geometry, appearance and spatial relations between the features can guide early reactive grasping which can later on be used in a more purposive manner when interacting with the environment.

  • 5. Aasi, Parisa
    et al.
    Nunes, Ivan
    Rusu, Lazar
    Hodosi, Georg
    Does Organizational Culture Matter in IT Outsourcing Relationships?2015Ingår i: 2015 48TH HAWAII INTERNATIONAL CONFERENCE ON SYSTEM SCIENCES (HICSS), IEEE Computer Society, 2015, s. 4691-4699Konferensbidrag (Refereegranskat)
    Abstract [en]

    IT Outsourcing (ITO) is used widely by Multinational Companies (MNCs) as a sourcing strategy today. ITO relationship between service buyer and provider then becomes a crucial issue in achieving expected objectives. This research sheds light on the influence of organizational culture (OC) of the buyer company on its ITO relationship with the provider. More specifically, the influence that OC can have on four significant dimensions of trust, cooperation, communication and commitment in ITO is studied through a qualitative analysis. IT managers of six MNCs were interviewed which exposed the connection between OC and ITO relationship factors. An open communication culture, speed of adaption to change, receiving innovative solutions, flat or hierarchical structures and responsibility degree appeared as the most visible differences between OCs of MNCs influencing ITO relationships. The results can be used for improving the ITO by considering the influence of OC to gain more benefits from outsourcing.

  • 6. Abaglo, A. J.
    et al.
    Bonalda, C.
    Pertusa, Emeline
    KTH.
    Environmental Digital Model: Integration of BIM into environmental building simulations2017Ingår i: CISBAT 2017 International ConferenceFuture Buildings & Districts – Energy Efficiency from Nano to Urban Scale, Elsevier, 2017, Vol. 122, s. 1063-1068Konferensbidrag (Refereegranskat)
    Abstract [en]

    The digital model and the BIM are creating a revolution with a transition from 2D to 3D models. However, environmental professions carry out building simulations with a wide range of software with little or no communication between them. This often leads to the realization of several 3D models and therefore a significant loss of time, as well as possible inconsistencies of geometrical information. Our research aims to use the interoperability potential offered by BIM-friendly software to develop gateways to optimize the modeling phase and improve the restitution of the studies through visual integration in a digital mockup.

  • 7.
    Abbas, Haider
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Options-Based Security-Oriented Framework for Addressing Uncerainty Issues in IT Security2010Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Continuous development and innovation in Information Technology introduces novel configuration methods, software development tools and hardware components. This steady state of flux is very desirable as it improves productivity and the overall quality of life in societies. However, the same phenomenon also gives rise to unseen threats, vulnerabilities and security concerns that are becoming more critical with the passage of time. As an implication, technological progress strongly impacts organizations’ existing information security methods, policies and techniques, making obsolete existing security measures and mandating reevaluation, which results in an uncertain IT infrastructure. In order to address these critical concerns, an options-based reasoning borrowed from corporate finance is proposed and adapted for evaluation of security architecture and decision- making to handle them at organizational level. Options theory has provided significant guidance for uncertainty management in several domains, such as Oil & Gas, government R&D and IT security investment projects. We have applied options valuation technique in a different context to formalize optimal solutions in uncertain situations for three specific and identified uncertainty issues in IT security. In the research process, we formulated an adaptation model for expressing options theory in terms useful for IT security which provided knowledge to formulate and propose a framework for addressing uncertainty issues in information security. To validate the efficacy of this proposed framework, we have applied this approach to the SHS (Spridnings- och Hämtningssystem) and ESAM (E-Society) systems used in Sweden. As an ultimate objective of this research, we intend to develop a solution that is amenable to automation for the three main problem areas caused by technological uncertainty in information security: i) dynamically changing security requirements, ii) externalities caused by a security system, iii) obsoleteness of evaluation. The framework is general and capable of dealing with other uncertainty management issues and their solutions, but in this work we primarily deal with the three aforementioned uncertainty problems. The thesis presents an in-depth background and analysis study for a proposed options-based security-oriented framework with case studies for SHS and ESAM systems. It has also been assured that the framework formulation follows the guidelines from industry best practices criteria/metrics. We have also proposed how the whole process can be automated as the next step in development.

  • 8.
    Abbas, Haider
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Data- och systemvetenskap, DSV.
    Threats and Security Measures Involved in VoIP-Telephony2006Självständigt arbete på avancerad nivå (magisterexamen), 30 poäng / 45 hpStudentuppsats (Examensarbete)
  • 9.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Magnusson, Christer
    Department of Computer and System Sciences, Stockholm University, Sweden.
    Yngström, Louise
    Department of Computer and System Sciences, Stockholm University, Sweden.
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Addressing Dynamic Issues in Information Security Management2011Ingår i: Information Management & Computer Security, ISSN 0968-5227, E-ISSN 1758-5805, Vol. 19, nr 1, s. 5-24Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose – The paper addresses three main problems resulting from uncertainty in information securitymanagement: i) dynamically changing security requirements of an organization ii) externalities caused by a securitysystem and iii) obsolete evaluation of security concerns.

    Design/methodology/approach – In order to address these critical concerns, a framework based on optionsreasoning borrowed from corporate finance is proposed and adapted to evaluation of security architecture anddecision-making for handling these issues at organizational level. The adaptation as a methodology is demonstrated by a large case study validating its efficacy.

    Findings – The paper shows through three examples that it is possible to have a coherent methodology, buildingon options theory to deal with uncertainty issues in information security at an organizational level.

    Practical implications – To validate the efficacy of the methodology proposed in this paper, it was applied tothe SHS (Spridnings- och Hämtningssystem: Dissemination and Retrieval System) system. The paper introduces themethodology, presents its application to the SHS system in detail and compares it to the current practice.

    Originality/value – This research is relevant to information security management in organizations, particularlyissues on changing requirements and evaluation in uncertain circumstances created by progress in technology.

  • 10.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Magnusson, Christer
    Department of Computer and System Sciences, Stockholm University, Sweden.
    Yngström, Louise
    Department of Computer and System Sciences, Stockholm University, Sweden.
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Architectural Description of an Automated System for Uncertainty Issues Management in Information Security2010Ingår i: International Journal of Computer Science and Information Security, ISSN 1947-5500, Vol. 8, nr 3, s. 89-67Artikel i tidskrift (Refereegranskat)
  • 11.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Magnusson, Christer
    Yngström, Louise
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    A Structured Approach for Internalizing Externalities Caused by IT Security Mechanisms2010Ingår i: IEEE ETCS 2010, Wuhan, China, 2010, s. 149-153Konferensbidrag (Refereegranskat)
    Abstract [en]

    Organizations relying on Information Technology for their business processes have to employ various Security Mechanisms (Authentication, Authorization, Hashing, Encryption etc) to achieve their organizational security objectives of data confidentiality, integrity and availability. These security mechanisms except from their intended role of increased security level for this organization may also affect other systems outside the organization in a positive or negative manner called externalities. Externalities emerge in several ways i.e. direct cost, direct benefit, indirect cost and indirect benefit. Organizations barely consider positive externalities although they can be beneficial and the negative externalities that could create vulnerabilities are simply ignored. In this paper, we will present an infrastructure to streamline information security externalities that appear dynamically for an organization

  • 12.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Magnusson, Christer
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Data- och systemvetenskap, DSV.
    Yngström, Louise
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Data- och systemvetenskap, DSV.
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Analyzing IT Security Evaluation needs for Developing Countries2009Ingår i: IPID Annual Workshop 2009, Orebro, Sweden, 2009Konferensbidrag (Övrigt vetenskapligt)
  • 13.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Sundkvist, Stefan
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Increasing the Performance of Crab Linux Router Simulation Package Using XEN2006Ingår i: IEEE International Conference on Industrial and Information Systems, Kandy, Sri Lanka, 2006, s. 459-462Konferensbidrag (Refereegranskat)
    Abstract [en]

    Nowadays hardware components are very expensive, especially if the prime purpose is to perform some routing related lab exercises. Physically connected network resources are required to get the desired results. Configuration of network resources in a lab exercise consumes much time of the students and scientists. The router simulation package Crab(1), based on KnoppW, Quagga' and User Mode Linux (UML) is designed for the students to facilitate them in performing lab exercises on a standalone computer where no real network equipment is needed. In addition to that it provides the facility of connection with the real network equipments. Crab also handles the pre configuration of different parts of the simulated networks like automatic IT addressing etc. This paper will describe the performance enhancing of Crab by replacing User Mode Linux virtual machine with XEN capable of providing ten virtual sessions concurrently using a standalone computer.

  • 14.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Yngström, Louise
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Adaptability Infrastructure for Bridging IT Security Evaluation and Options Theory2009Ingår i: ACM- IEEE SIN 2009 International Conference on Security of Information and Networks, North Cyprus, 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    The constantly rising threats in IT infrastructure raise many concerns for an organization, altering security requirements according to dynamically changing environment, need of midcourse decision management and deliberate evaluation of security measures are most striking. Common Criteria for IT security evaluation has long been considered to be victimized by uncertain IT infrastructure and considered resource hungry, complex and time consuming process. Considering this aspect we have continued our research quest for analyzing the opportunities to empower IT security evaluation process using Real Options thinking. The focus of our research is not only the applicability of real options analysis in IT security evaluation but also observing its implications in various domains including IT security investments and risk management. We find it motivating and worth doing to use an established method from corporate finance i.e. real options and utilize its rule of thumb technique as a road map to counter uncertainty issues for evaluation of IT products. We believe employing options theory in security evaluation will provide the intended benefits. i.e. i) manage dynamically changing security requirements ii) accelerating evaluation process iii) midcourse decision management. Having all the capabilities of effective uncertainty management, options theory follows work procedures based on mathematical calculations quite different from information security work processes. In this paper, we will address the diversities between the work processes of security evaluation and real options analysis. We present an adaptability infrastructure to bridge the gap and make them coherent with each other. This liaison will transform real options concepts into a compatible mode that provides grounds to target IT security evaluation and common criteria issues. We will address ESAM system as an example for illustrations and applicability of the concepts.

  • 15.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Yngström, Louise
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Empowering Security Evaluation of IT Products with Options Theory2009Ingår i: 30th IEEE Symposium on Security & Privacy, Oakland, USA, 2009Konferensbidrag (Refereegranskat)
  • 16.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Yngström, Louise
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Option Based Evaluation: Security Evaluation of IT Products Based on Options Theory2009Ingår i: IEEE  ECBS-EERC 2009, New York: IEEE , 2009, s. 134-141Konferensbidrag (Refereegranskat)
    Abstract [en]

    Reliability of IT systems and infrastructure is a critical need for organizations to trust their business processes. This makes security evaluation of IT systems a prime concern for these organizations. Common Criteria is an elaborate, globally accepted security evaluation process that fulfills this need. However CC rigidly follows the initial specification and security threats and takes too long to evaluate and as such is also very expensive. Rapid development in technology and with it the new security threats further aggravates the long evaluation time problem of CC to the extent that by the time a CC evaluation is done, it may no longer be valid because new security threats have emerged that have not been factored in. To address these problems, we propose a novel Option Based Evaluation methodology for security of IT systems that can also be considered as an enhancement to the CC process. The objective is to address uncertainty issues in IT environment and speed up the slow CC based evaluation processes. OBE will follow incremental evaluation model and address the following main concerns based on options theory i.e. i) managing dynamic security requirement with mid-course decision management ii) devising evaluation as an improvement process iii) reducing cost and time for evaluation of an IT product.

  • 17.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Yngström, Louise
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    ROA Based Agile Security Evaluation of IT Products for Developing Countries2009Ingår i: IPID 4th Annual Conference 2009, London, UK, 2009Konferensbidrag (Övrigt vetenskapligt)
  • 18.
    Abbas, Haider
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Yngström, Louise
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Data- och systemvetenskap, DSV.
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik- och datorsystem, ECS.
    Security Evaluation of IT Products: Bridging the Gap between Common Criteria (CC) and Real Option Thinking2008Ingår i: WCECS 2008: WORLD CONGRESS ON ENGINEERING AND COMPUTER SCIENCE, 2008, s. 530-533Konferensbidrag (Refereegranskat)
    Abstract [en]

    Information security has long been considered as a key concern for organizations benefiting from the electronic era. Rapid technological developments have been observed in the last decade which has given rise to novel security threats, making IT, an uncertain infrastructure. For this reason, the business organizations have an acute need to evaluate the security aspects of their IT infrastructure. Since many years, CC (Common Criteria) has been widely used and accepted for evaluating the security of IT products. It does not impose predefined security rules that a product should exhibit but a language for security evaluation. CC has certain advantages over ITSEC1, CTCPEC2 and TCSEC3 due to its ability to address all the three dimensions: a) it provides opportunity for users to specify their security requirements, b) an implementation guide for the developers and c) provides comprehensive criteria to evaluate the security requirements. Among the few notable shortcomings of CC is the amount of resources and a lot of time consumption. Another drawback of CC is that the security requirements in this uncertain IT environment must be defined before the project starts. ROA is a well known modern methodology used to make investment decisions for the projects under uncertainty. It is based on options theory that provides not only strategic flexibility but also helps to consider hidden options during uncertainty. ROA comes in two flavors: first for the financial option pricing and second for the more uncertain real world problems where the end results are not deterministic. Information security is one of the core areas under consideration where researchers are employing ROA to take security investment decisions. In this paper, we give a brief introduction of ROA and its use in various domains. We will evaluate the use of Real options based methods to enhance the Common Criteria evaluation methodology to manage the dynamic security requirement specification and reducing required time and resources. We will analyze the possibilities to overcome CC limitations from the perspective of the end user, developer and evaluator. We believe that with the ROA enhanced capabilities will potentially be able to stop and possibly reverse this trend and strengthen the CC usage with a more effective and responsive evaluation methodology.

  • 19.
    Abbas, Sahib
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Lösning till mobilitetsproblem samt tillgänglighet till hemsidan för Iraks ambassad2014Självständigt arbete på avancerad nivå (masterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Att använda internet nuförtiden har blivit en del av vardagen. Det känns som att Internet har delat världen i många delar där varje del delar med sig information i många olika former som placeras i olika kategorier. Vi delar information på många olika sätt, men det snabbaste och lättaste sättet är att sprida information med internet.

    Tekniken kommer med nya ideer kontinuerligt och vi utvecklar nya metoder som gör det ännu lättare för oss människor att få in information som vi forsöker att nå via internet. Två av de mest kända sätten där man kan dela med sig information är hemsidor och med "native" applikationer.

    Jag utförde exjobbet på lrakiska ambassaden. Det är en statlig irakisk organisation som ligger pa Baldersgatan 6A Stockholm. Huvuduppgift på ambassaden är att hjälpa irakisk- ­och icke irakiska medborgare som är bosatta i Sverige med vissa uppgifter.

    Ambassaden har mycket information som de försöker att dela med sig så mycket som möjligt av via hemsidan så att de minskar av det strulet de har. Hemsidan som ambassaden hade var ostrukturerad, och hade en tråkig design som ledde till att användaren fick svårigbeter med att lätt hitta det man söker.

    Detta examensarbete presenterar min lösning av problemen till ambassaden. Den är att bygga en helt ny hemsida som är mobilanpassad, som har bättre design ocb är mer strukturerad hemsida än den gamla hemsidan de hade. På så sätt så blir det mycket lättare för användaren att använda hemsidan. Samtidigt löser den mobilitetsproblemet, eftersom ambassaden började med att utveckla en native app till Iphone men projektet avbröts halvvägs för att det kostade för mycket och man insåg att det skulle uppstå ännu mer kostnader for att utveckla native appar till android ocb övriga operativ systemen. Detta examensarbete beskriver också hur man skulle kunna utveckla en mobilanpassad hemsida, vilka metoder ocb modeller som jag har använt mig av till utvecklingen av hemsidan, samt resultaten jag hade fått av de metoder som användes till utveckling av detta projekt.

  • 20. Abbasi, A. G.
    et al.
    Muftic, Sead
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Data- och systemvetenskap, DSV.
    Schmölzer, Gernot
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Data- och systemvetenskap, DSV.
    CryptoNET: Secure federation protocol and authorization policies for SMI2009Ingår i: Post-Proceedings of the 4th International Conference on Risks and Security of Internet and Systems, CRiSIS 2009, 2009, s. 19-25Konferensbidrag (Refereegranskat)
    Abstract [en]

    The paper describes a protocol for Secure E-Mail Infrastructure for establishing trust between different domains in order to protect mail servers from spam messages. The protocol uses messages for trusted interactions between intra and inter E-mail domain components, Secure E-mail (SEM) servers and Secure Mail Infrastructure (SMI) servers. In addition, the protocol validates E-mail addresses thus guaranteeing to the recipient that the E-mail is coming from a trusted domain. We also use XACML-based authorization policies at the sending and receiving servers, enforced by associated Policy Enforcement Point (PEP) servers at SEM servers, in order to provide a complete protection against spam.

  • 21.
    Abbasi, Abdul Ghafoor
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    CryptoNET: Generic Security Framework for Cloud Computing Environments2011Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    The area of this research is security in distributed environment such as cloud computing and network applications. Specific focus was design and implementation of high assurance network environment, comprising various secure and security-enhanced applications. “High Assurance” means that

    -               our system is guaranteed to be secure,

    -               it is verifiable to provide the complete set of security services,

    -               we prove that it always functions correctly, and

    -               we justify our claim that it can not be compromised without user neglect and/or consent.

     

    We do not know of any equivalent research results or even commercial security systems with such properties. Based on that, we claim several significant research and also development contributions to the state–of–art of computer networks security.

    In the last two decades there were many activities and contributions to protect data, messages and other resources in computer networks, to provide privacy of users, reliability, availability and integrity of resources, and to provide other security properties for network environments and applications. Governments, international organizations, private companies and individuals are investing a great deal of time, efforts and budgets to install and use various security products and solutions. However, in spite of all these needs, activities, on-going efforts, and all current solutions, it is general belief that the security in today networks and applications is not adequate.

    At the moment there are two general approaches to network application’s security. One approach is to enforce isolation of users, network resources, and applications. In this category we have solutions like firewalls, intrusion–detection systems, port scanners, spam filters, virus detection and elimination tools, etc. The goal is to protect resources and applications by isolation after their installation in the operational environment. The second approach is to apply methodology, tools and security solutions already in the process of creating network applications. This approach includes methodologies for secure software design, ready–made security modules and libraries, rules for software development process, and formal and strict testing procedures. The goal is to create secure applications even before their operational deployment. Current experience clearly shows that both approaches failed to provide an adequate level of security, where users would be guaranteed to deploy and use secure, reliable and trusted network applications.

    Therefore, in the current situation, it is obvious that a new approach and a new thinking towards creating strongly protected and guaranteed secure network environments and applications are needed. Therefore, in our research we have taken an approach completely different from the two mentioned above. Our first principle is to use cryptographic protection of all application resources. Based on this principle, in our system data in local files and database tables are encrypted, messages and control parameters are encrypted, and even software modules are encrypted. The principle is that if all resources of an application are always encrypted, i.e. “enveloped in a cryptographic shield”, then

    -               its software modules are not vulnerable to malware and viruses,

    -               its data are not vulnerable to illegal reading and theft,

    -               all messages exchanged in a networking environment are strongly protected, and

    -               all other resources of an application are also strongly protected.

     

    Thus, we strongly protect applications and their resources before they are installed, after they are deployed, and also all the time during their use.

    Furthermore, our methodology to create such systems and to apply total cryptographic protection was based on the design of security components in the form of generic security objects. First, each of those objects – data object or functional object, is itself encrypted. If an object is a data object, representing a file, database table, communication message, etc., its encryption means that its data are protected all the time. If an object is a functional object, like cryptographic mechanisms, encapsulation module, etc., this principle means that its code cannot be damaged by malware. Protected functional objects are decrypted only on the fly, before being loaded into main memory for execution. Each of our objects is complete in terms of its content (data objects) and its functionality (functional objects), each supports multiple functional alternatives, they all provide transparent handling of security credentials and management of security attributes, and they are easy to integrate with individual applications. In addition, each object is designed and implemented using well-established security standards and technologies, so the complete system, created as a combination of those objects, is itself compliant with security standards and, therefore, interoperable with exiting security systems.

    By applying our methodology, we first designed enabling components for our security system. They are collections of simple and composite objects that also mutually interact in order to provide various security services. The enabling components of our system are:  Security Provider, Security Protocols, Generic Security Server, Security SDKs, and Secure Execution Environment. They are all mainly engine components of our security system and they provide the same set of cryptographic and network security services to all other security–enhanced applications.

    Furthermore, for our individual security objects and also for larger security systems, in order to prove their structural and functional correctness, we applied deductive scheme for verification and validation of security systems. We used the following principle: “if individual objects are verified and proven to be secure, if their instantiation, combination and operations are secure, and if protocols between them are secure, then the complete system, created from such objects, is also verifiably secure”. Data and attributes of each object are protected and secure, and they can only be accessed by authenticated and authorized users in a secure way. This means that structural security properties of objects, upon their installation, can be verified. In addition, each object is maintained and manipulated within our secure environment so each object is protected and secure in all its states, even after its closing state, because the original objects are encrypted and their data and states stored in a database or in files are also protected.

    Formal validation of our approach and our methodology is performed using Threat Model. We analyzed our generic security objects individually and identified various potential threats for their data, attributes, actions, and various states. We also evaluated behavior of each object against potential threats and established that our approach provides better protection than some alternative solutions against various threats mentioned. In addition, we applied threat model to our composite generic security objects and secure network applications and we proved that deductive approach provides better methodology for designing and developing secure network applications. We also quantitatively evaluated the performance of our generic security objects and found that the system developed using our methodology performs cryptographic functions efficiently.

    We have also solved some additional important aspects required for the full scope of security services for network applications and cloud environment: manipulation and management of cryptographic keys, execution of encrypted software, and even secure and controlled collaboration of our encrypted applications in cloud computing environments. During our research we have created the set of development tools and also a development methodology which can be used to create cryptographically protected applications. The same resources and tools are also used as a run–time supporting environment for execution of our secure applications. Such total cryptographic protection system for design, development and run–time of secure network applications we call CryptoNET system. CrytpoNET security system is structured in the form of components categorized in three groups: Integrated Secure Workstation, Secure Application Servers, and Security Management Infrastructure Servers. Furthermore, our enabling components provide the same set of security services to all components of the CryptoNET system.

    Integrated Secure Workstation is designed and implemented in the form of a collaborative secure environment for users. It protects local IT resources, messages and operations for multiple applications. It comprises four most commonly used PC applications as client components: Secure Station Manager (equivalent to Windows Explorer), Secure E-Mail Client, Secure Web Browser, and Secure Documents Manager. These four client components for their security extensions use functions and credentials of the enabling components in order to provide standard security services (authentication, confidentiality, integrity and access control) and also additional, extended security services, such as transparent handling of certificates, use of smart cards, Strong Authentication protocol, Security Assertion Markup Language (SAML) based Single-Sign-On protocol, secure sessions, and other security functions.

    Secure Application Servers are components of our secure network applications: Secure E-Mail Server, Secure Web Server, Secure Library Server, and Secure Software Distribution Server. These servers provide application-specific services to client components. Some of the common security services provided by Secure Application Servers to client components are Single-Sign-On protocol, secure communication, and user authorization. In our system application servers are installed in a domain but it can be installed in a cloud environment as services. Secure Application Servers are designed and implemented using the concept and implementation of the Generic Security Server. It provides extended security functions using our engine components. So by adopting this approach, the same sets of security services are available to each application server.

    Security Management Infrastructure Servers provide domain level and infrastructure level services to the components of the CryptoNET architecture. They are standard security servers, known as cloud security infrastructure, deployed as services in our domain level could environment.

    CryptoNET system is complete in terms of functions and security services that it provides. It is internally integrated, so that the same cryptographic engines are used by all applications. And finally, it is completely transparent to users – it applies its security services without expecting any special interventions by users. In this thesis, we developed and evaluated secure network applications of our CryptoNET system and applied Threat Model to their validation and analysis. We found that deductive scheme of using our generic security objects is effective for verification and testing of secure, protected and verifiable secure network applications.

    Based on all these theoretical research and practical development results, we believe that our CryptoNET system is completely and verifiably secure and, therefore, represents a significant contribution to the current state-of-the-art of computer network security.

  • 22.
    Abbasi, Abdul Ghafoor
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Muftic, Sead
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    CryptoNET: Security Management Protocols2010Ingår i: ADVANCES IN DATA NETWORKS, COMMUNICATIONS, COMPUTERS / [ed] Mastorakis, NE; Mladenov, V, ATHENS: WORLD SCIENTIFIC AND ENGINEERING ACAD AND SOC , 2010, s. 15-20Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper we describe several network security protocols used by various components of CryptoNET architecture. The protocols are based on the concept of generic security objects and on well-established security standards and technologies. Distinctive features of our security protocols are: (1) they are complete in terms of their functionality, (2) they are easy to integrate with applications, (3) they transparently handle security credentials and protocol-specific attributes using FIPS 201 (PIV) smart cards, and (4) they are based on generic security objects. These protocols are: remote user authentication protocol, single-sign-on protocol, SAML authorization protocol, and secure sessions protocol. Security protocols use our Security Provider as a collection of cryptographic engines implemented either in software or using FIPS 201 (NV) smart cards. It also manages protocols' attributes using security applets stored in Ply smart card.

  • 23.
    Abbasi, Abdul Ghafoor
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01).
    Muftic, Sead
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01).
    Hotamov, I.
    Web contents protection, secure execution and authorized distribution2010Ingår i: Proceedings - 5th International Multi-Conference on Computing in the Global Information Technology, ICCGI 2010, 2010, s. 157-162Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes the design and implementation of a comprehensive system for protection of Web contents. In this design, new security components and extended security features are introduced in order to protect Web contents ageist various Web attacks. Components and extended security features are: protection of Web pages using strong encryption techniques, encapsulation of Web contents and resources in PKCS#7, extended secure execution environment for Java Web Server, eXtensible Access Control Markup Language (XACML) based authorization policies, and secure Web proxy. Design and implementation of our system is based on the concepts of generic security objects and component-based architecture that makes it compatible with exiting Web infrastructures without any modification.

  • 24.
    Abbasi, Azad Ismail
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Coffeepot for Masochists: A Study in User-Centered System Design2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Sammanfattning

    Kaffepanna för Masochister

    En studie i Användarcentrerad Systemdesign

     

    Detta examensarbete har utförts inom området för ”Människa-Datorinteraktion” mer specifikt ”Användarcentrerad Systemdesign”. Fokus har varit på ”användbarhet” och användbart grafiskt användargränssnitt. Aktuella teorier och definitioner har iakttagits. Litteraturstudien har omfattat välkända författare och organisationer i ovannämnda domäner; Jakob Nielsen, Donald A Norman och Internationella standardiseringsorganisationen ISO för att nämna några.

     

    En annan källa vars teorier och arbetssätt har tillämpats i detta arbete är boken ”Användarcentrerad Systemdesign” av författarna Jan Gulliksen och Bengt Göransson.

     

    Arbetet började med en litteraturstudie följd av val av lämplig metod. Nästa steg innebar att utföra uppgifts- och användaranalyser och därefter var det dags för utvecklingsfasen. Användaren har  haft en  central  roll  i  detta  projekt  och har,  precis  som  rekommenderat, involverats i samtliga  moment. En lämplig och nyttig metod för att få återkoppling från användarna, förutom intervjuer och workshop, har varit ”Heuristisk Utvärdering”.

     

    Det slutliga resultatet och slutsatsen visar att användarcentrerad systemdesign är ett kraftfullt verktyg att nyttja när det kommer till design och utveckling av interaktivt användargränssnitt.

  • 25.
    Abbaszadeh Shahri, Abbas
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap. Islamic Azad University.
    An Optimized Artificial Neural Network Structure to Predict Clay Sensitivity in a High Landslide Prone Area Using Piezocone Penetration Test (CPTu) Data: A Case Study in Southwest of Sweden2016Ingår i: Geotechnical and Geological Engineering, ISSN 0960-3182, E-ISSN 1573-1529, s. 1-14Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Application of artificial neural networks (ANN) in various aspects of geotechnical engineering problems such as site characterization due to have difficulty to solve or interrupt through conventional approaches has demonstrated some degree of success. In the current paper a developed and optimized five layer feed-forward back-propagation neural network with 4-4-4-3-1 topology, network error of 0.00201 and R2 = 0.941 under the conjugate gradient descent ANN training algorithm was introduce to predict the clay sensitivity parameter in a specified area in southwest of Sweden. The close relation of this parameter to occurred landslides in Sweden was the main reason why this study is focused on. For this purpose, the information of 70 piezocone penetration test (CPTu) points was used to model the variations of clay sensitivity and the influences of direct or indirect related parameters to CPTu has been taken into account and discussed in detail. Applied operation process to find the optimized ANN model using various training algorithms as well as different activation functions was the main advantage of this paper. The performance and feasibility of proposed optimized model has been examined and evaluated using various statistical and analytical criteria as well as regression analyses and then compared to in situ field tests and laboratory investigation results. The sensitivity analysis of this study showed that the depth and pore pressure are the two most and cone tip resistance is the least effective factor on prediction of clay sensitivity.

  • 26. Abbeloos, W.
    et al.
    Caccamo, Sergio
    KTH, Skolan för datavetenskap och kommunikation (CSC), Robotik, perception och lärande, RPL.
    Ataer-Cansizoglu, E.
    Taguchi, Y.
    Feng, C.
    Lee, T. -Y
    Detecting and Grouping Identical Objects for Region Proposal and Classification2017Ingår i: 2017 IEEE Computer Society Conference on Computer Vision and Pattern Recognition Workshops, IEEE Computer Society, 2017, Vol. 2017, s. 501-502, artikel-id 8014810Konferensbidrag (Refereegranskat)
    Abstract [en]

    Often multiple instances of an object occur in the same scene, for example in a warehouse. Unsupervised multi-instance object discovery algorithms are able to detect and identify such objects. We use such an algorithm to provide object proposals to a convolutional neural network (CNN) based classifier. This results in fewer regions to evaluate, compared to traditional region proposal algorithms. Additionally, it enables using the joint probability of multiple instances of an object, resulting in improved classification accuracy. The proposed technique can also split a single class into multiple sub-classes corresponding to the different object types, enabling hierarchical classification.

  • 27. Abd El Ghany, M. A.
    et al.
    El-Moursy, M. A.
    Ismail, Mohammed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem. Ohio State University, Columbus, United States .
    High throughput architecture for high performance NoC2009Ingår i: ISCAS: 2009 IEEE International Symposium on Circuits and Systems, IEEE , 2009, s. 2241-2244Konferensbidrag (Refereegranskat)
    Abstract [en]

    High Throughput Butterfly Fat Tree (HTBFT) architecture to achieve high performance Networks on Chip (NoC) is proposed. The architecture increases the throughput of the network by 38% while preserving the average latency. The area of HTBFT switch is decreased by 18% as compared to Butterfly Fat Tree switch. The total metal resources required to implement HTBFT design is increased by 5% as compared to the total metal resources required to implement BFT design. The extra power consumption required to achieve the proposed architecture is 3% of the total power consumption of the BFT architecture.

  • 28.
    ABDALMAHMOODABADI, MAHBOOBEH
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    The value of downstream information sharing in two-level supply chain: AN APPROACH TO AGENT-BASED MODELING2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Många försörjningskedjan företag har tagit initiativ för att underlätta efterfrågan informationsutbyte mellan nedströms och uppströms enheter. Informationsutbyte är en nyckelfaktor för samarbete inom supply chain management (SCM). Under de senaste decennierna har många ansträngningar gjorts för att modellera distributionskedjan matematiskt. Matematiska modeller är oförmögna att fånga den dynamiska karaktären i systemet. Det är nödvändigt att studera flerdimensionell försörjningskedjan modell där inte bara det finns kommunikation mellan leverantör och återförsäljare men även kommunikation mellan återförsäljare måste övervägas. Matematiska modeller kan ses som en enkel beslutsfattande optimering mellan två enheter där effekten av samarbete med andra enheter är helt ignoreras. Dessa modeller är långt ifrån verkliga system. Syftet med denna avhandling är att skapa en agentbaserad modell, som ersättning för matematisk modellering, för att bedöma vikten av att dela information om leverantörssidan när det finns samband mellan återförsäljare genom aktiedelning. Den konceptuella modellen av två-Echelon leveranskedjan utformas och genomförs i Java med hjälp Repast kostym. Modellen omfattar fyra typer av agenter nämligen leveranskedjan, leverantörs, återförsäljare och förmedlar medel som interagerar med varandra i en diskret händelsebaserad simulering. Multi faktornivå används för att utvärdera resultatet av leveranskedjan, när det gäller den totala kostnadsbesparingar, under olika efterfrågemönster. Den stora skillnaden mellan experimentella inställningar testas statistiskt med hjälp av ANOVA, Parvis, och Univariata tester. Dataanalys visar att betydelsen av informationsutbyte kan vara ganska hög, i synnerhet när slutkundernas krav avsevärt korrelerade. En sådan kostnadsbesparingar som uppnås genom att dela information beror på att minska lagernivån och på bekostnad av att öka mängden av rest.

  • 29.
    Abdelmassih, Christian
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Hultman, Axel
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Förutspå golfresultat med hjälp av sentimentanalys på Twitter2016Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Denna studie undersöker möjligheten att med hjälp av sentimentanalys av golfspelares twitterkonton kunna förutsäga deras kommande resultat. Studien baserades på två dataset: 155 professionella golfares resultat och 112 101 tweets insamlade från två säsonger på PGA­touren. Vår studie kan vara av intresse för till exempel spelbolag, spelare, tränare och fans.

    Det känslor golfspelarna uttryckt i sina tweets kvantifierades till ett siffervärde med hjälp av den lexikala sentimentsanalysmetoden AFINN. Resultaten av vår studie visar på mycket låg korrelation mellan de insamlade dataseten och att sentimentvärdena innehar en låg grad av prediktiv förmåga. Dessa resultat står i kontrast mot liknande forskning utförd på annan sport. Vår rekommendation för framtida studier är att basera modellen på fler variabler utöver sentimentvärde för att tydligare klargöra hur de känslor golfspelare uttrycker på twitter kan användas för att förutspå deras kommande resultat.

  • 30.
    Abdlwafa, Alan
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Edman, Henrik
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Distributed Graph Mining: A study of performance advantages in distributed data mining paradigms when processing graphs using PageRank on a single node cluster2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Distributed data mining is a relatively new area within computer science that is steadily growing, emerging from the demands of being able to gather and process various distributed data by utilising clusters. This report presents the properties of graph structured data and what paradigms to use for efficiently processing the data type, based on comprehensive theoretical studies applied on practical tests performed on a single node cluster. The results in the study showcase the various performance aspects of processing graph data, using different open source paradigm frameworks and amount of shards used on input. A conclusion to be drawn from this study is that there are no real performance advantages to using distributed data mining paradigms specifically developed for graph data on single machines. 

  • 31.
    Abdulaziz Ali Haseeb, Mohamed
    KTH, Skolan för datavetenskap och kommunikation (CSC), Robotik, perception och lärande, RPL.
    Passive gesture recognition on unmodified smartphones using Wi-Fi RSSI2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Smarta telefoner bärs idag av hundratals miljoner människor runt om i världen, och används för att utföra en mängd olika uppgifter, så som grundläggande kommunikation, internetsökning och online-inköp. På grund av begränsningar i storlek och energilagring är människa-telefon-gränssnitten dock i hög grad begränsade till de förhållandevis små skärmarna och enkla knappsatser.

     

    Industrin och forskarsamhället arbetar för att hitta vägar för att förbättra och bredda gränssnitten genom att antingen använda befintliga resurser såsom mikrofoner, kameror och tröghetssensorer, eller genom att införa nya specialiserade sensorer i telefonerna, som t.ex. kompakta radarenheter för gestigenkänning.

     

    Det begränsade strömbehovet hos radiofrekvenssignaler (RF) inspirerade oss till att undersöka om dessa kunde användas för att känna igen gester och aktiviteter i närheten av telefoner. Denna rapport presenterar en lösning för att känna igen gester med hjälp av ett s.k. recurrent neural network (RNN). Till skillnad från andra Wi-Fi-baserade lösningar kräver denna lösning inte en förändring av vare sig hårvara eller operativsystem, och ingenkänningen genomförs utan att inverka på den normala driften av andra applikationer på telefonen.

     

    Den utvecklade lösningen når en genomsnittlig noggranhet på 78% för detektering och klassificering av tre olika handgester, i ett antal olika konfigurationer vad gäller telefon och Wi-Fi-sändare. Rapporten innehåller även en analys av flera olika egenskaper hos den föreslagna lösningen, samt förslag till vidare arbete.

  • 32.
    Abdulla, Muntazar
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Cu-tråd som elektrisk ledare i CIGS-tunnfilmssolceller för att sänka silvermängden utan att förlora verkningsgrad2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Solcellsbranschen är större än någonsin tidigare och fortsätter växa samtidigt som konkurrensen mellan solcellstillverkare ökar, detta är något som pressar ner priserna på solceller och minskar lönsamheten för tillverkarna. Därför fokuserar detta projekt på hur man kan sänka mängden silver i solcellen utan att förlora verkningsgrad. Detta genomförs genom att arbeta som en problemlösare ihop med egna idéer. Genom att dra nytta av fördelarna med koppartrådar och skapa ett nytt solcellsmönster är detta möjligt då silver utgör 1/5 av tillverkningskostnaden. Projektet domineras av praktiskt arbete med fokus på innovation av standardsolcellen. Resultatet visade att man kan sänka silverpasta mängden med upp till 70 % i varje solcell genom att ta fram ett nytt silvertryck med mycket mindre silver ihop med koppartrådar. Det användes silver-belagda koppartrådar som ledare för att leda ut ström från ytan med fördelarna att det är tunna och blockerar därför solljuset mindre. Resultaten gav en verkningsgrad på 10-11% vilket är i nivå med produktionssolcellsmodulerna på Midsummer. Systemet bevisades även stabilt.

  • 33. Abdullah, Matin
    et al.
    Feig, Michael
    Pettitt, Montgomery
    Johnsson, Lennart
    KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Parallelldatorcentrum, PDC.
    SimDB: A Problem Solving Environment for Molecular Dynamics Simulation and Analysis2000Konferensbidrag (Refereegranskat)
    Abstract [en]

    The design of a software environment, SimDB, for molecular dynamics simulation and analysis is presented as an example of virtual laboratories enabled by high-speed networks connecting substantial computing and storage resources with more modest local compuation and visualization resources available to research groups. SimDB includes large-scale, dynamic, distributed data repositories. The simulated data sets, trajectories, are usually interpreted through reduced data sets, processed data sets, calculated by analysis functions. Both trajectory data and processed data are saved, but in differnt data bases, with processed data bases having several smaller objects for each trajectory. A browser based user interface with a well defined API allows for a wide array of analysis functions. Analysis functions are executed only if the requested analysis result is not available. The ability to incorporate user defined functions is a critical feature of SimDB.

  • 34.
    Abdullah, Nazri
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Programvaruteknik och Datorsystem, SCS.
    Håkansson, Anne
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Programvaruteknik och Datorsystem, SCS.
    Moradian, E.
    Blockchain based approach to enhance big data authentication in distributed environment2017Ingår i: 2017 Ninth International Conference on Ubiquitous and Future Networks (ICUFN), IEEE Computer Society, 2017, s. 887-892Konferensbidrag (Refereegranskat)
    Abstract [en]

    Existing authentication protocols for Big Data system such as Apache Hadoop is based on Kerberos. In the Kerberos protocol, there are numerous security issues that have remained unsolved; replay attacks, DDoS and single point of failure are some examples. These indicate potential security vulnerabilities and Big Data risks in using Hadoop. This paper presents drawbacks of Kerberos implementations and identifies authentication requirements that can enhance the security of Big Data in distributed environments. The enhancement proposed is based on the rising technology of blockchain that overcomes shortcomings of Kerberos.

  • 35. Abdulle, A.
    et al.
    Engquist, Björn
    Mathematics Department, University of Texas at Austin.
    Finite element heterogeneous multiscale methods with near optimal computational complexity2007Ingår i: Multiscale Modeling & simulation, ISSN 1540-3459, E-ISSN 1540-3467, Vol. 6, nr 4, s. 1059-1084Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper is concerned with a numerical method for multiscale elliptic problems. Using the framework of the heterogeneous multiscale methods (HMM), we propose a micro-macro approach which combines the finite element method (FEM) for the macroscopic solver and the pseudospectral method for the microsolver. Unlike the micro-macromethods based on the standard FEM proposed so far, in the HMM we obtain, for periodic homogenization problems, a method that (slow) variable.

  • 36.
    Abefelt, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Synchronized audio playback over WIFI and Ethernet: A proof of concept multi-room audio playback system2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Huvuduppgift med detta examensarbete har varit att utveckla ett synkroniserat ljuduppspelningssystem, vilket kan spela upp ljud samtidigt på flera enheter, enheterna är anslutna med antingen med Wi-Fi eller Ethernet. Två olika tillvägagångsätt har undersökts för att utveckla systemet, ett redan färdigt system och ett system baserat på ett ramverk med öppen källkod.

    Det utvecklade systemet kan utföra synkroniserad uppspelning på fem olika enheter och kan använda Blueetooth enheter och olika mediaspelare som ljudkälla.

  • 37.
    Abenius, Erik
    KTH, Tidigare Institutioner, Numerisk analys och datalogi, NADA.
    Time-Domain Inverse Electromagnetic Scattering using FDTD and Gradient-based Minimization2004Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    The thesis addresses time-domain inverse electromagneticscattering for determining unknown characteristics of an objectfrom observations of the scattered .eld. Applications includenon-destructive characterization of media and optimization ofmaterial properties, for example the design of radar absorbingmaterials.A nother interesting application is the parameteroptimization of subcell models to avoid detailed modeling ofcomplex geometries.

    The inverse problem is formulated as an optimal controlproblem where the cost function to be minimized is thedi.erence between the estimated and observed .elds, and thecontrol parameters are the unknown object characteristics. Theproblem is solved in a deterministic gradient-basedoptimization algorithm using a parallel 2D FDTD scheme for thedirect problem.This approach is computationally intensive sincethe direct problem needs to be solved in every optimizationiteration in order to compute an estimated .eld.H ighlyaccurate analytical gradients are computed from the adjointformulation.In addition to giving better accuracy than .nitedi.erences, the analytical gradients also have the advantage ofonly requiring one direct and one adjoint problem to be solvedregardless of the number of parameters.

    When absorbing boundary conditions are used to truncate thecomputational domain, the equations are non-reversible and theentire time-history of the direct solution needs to be storedfor the gradient computation.Ho wever, using an additionaldirect simulation and a restart procedure it is possible tokeep the storage at an acceptable level.

    The inverse method has been successfully applied to a widerange of industrial problems within the European project,IMPACT (Inverse Methods for Wave Propagation Applications inTime-Domain).T he results presented here includecharacterization of layered dispersive media, determination ofparameters in subcell models for thin sheets and narrow slotsand optimization problems where the observed .eld is given bydesign objectives.

  • 38.
    Abensour Sellström, Gabriel
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Runefelt Tõnisson, Meidi
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Analysis of Voting Algorithms: a comparative study of the Single Transferable Vote.2012Självständigt arbete på avancerad nivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Ett valsystem är det tillvägagångssätt med vilket den politiska makten fördelas bland kandidater efter ett val. Den här uppsatsen syftar till att jämföra valsystemet "enkel överförbar röst" med två andra valsystem, genom att konstruera Java-implementationer av algoritmerna för att köra exempeldata i. På så sätt utvärderar vi möjligheten att använda systemet med "enkel överförbar röst" i svenska riksdagsval. Utöver det föreslås en alternativ version av det ursprungliga systemet "enkel överförbar röst", där modifikationer gjorts för att passa de förutsättningar som råder i Sverige. Effekterna av ett sådant byte av valsystem är inte helt klarlagda och slutsatsen är att mer forskning krävs innan det finns grund för ett definitivt omdöme.

  • 39. Abeywardena, D.
    et al.
    Wang, Zhan
    KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP. KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Centrum för Autonoma System, CAS.
    Dissanayake, G.
    Waslander, S. L.
    Kodagoda, S.
    Model-aided state estimation for quadrotor micro air vehicles amidst wind disturbances2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper extends the recently developed Model-Aided Visual-Inertial Fusion (MA-VIF) technique for quadrotor Micro Air Vehicles (MAV) to deal with wind disturbances. The wind effects are explicitly modelled in the quadrotor dynamic equations excluding the unobservable wind velocity component. This is achieved by a nonlinear observability of the dynamic system with wind effects. We show that using the developed model, the vehicle pose and two components of the wind velocity vector can be simultaneously estimated with a monocular camera and an inertial measurement unit. We also show that the MA-VIF is reasonably tolerant to wind disturbances, even without explicit modelling of wind effects and explain the reasons for this behaviour. Experimental results using a Vicon motion capture system are presented to demonstrate the effectiveness of the proposed method and validate our claims.

  • 40. Abeywickrama, S.
    et al.
    Furdek, Marija
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). University of Zagreb, Faculty of Electrical Engineering and Computing, Dept. of Telecommunications, Croatia.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Nag, A.
    Wong, E.
    Dual-homing based protection for enhanced network availability and resource efficiency2014Ingår i: Asia Communications and Photonics Conference, ACP, 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    An approach to enhance core network survivability by utilizing dual-homing capabilities of the access network. Results reveal significant improvements in core network resource utilization and connection availability, suggesting benefits to network operators and service providers.

  • 41.
    Abid, Muhammad Zeeshan
    KTH, Skolan för informations- och kommunikationsteknik (ICT). Technische Universität Braunschweig.
    A Multi-leader Approach to Byzantine Fault Tolerance: Achieving Higher Throughput Using Concurrent Consensus2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Byzantine Fault Tolerant protocols are complicated and hard to implement.Today’s software industry is reluctant to adopt these protocols because of thehigh overhead of message exchange in the agreement phase and the high resourceconsumption necessary to tolerate faults (as 3 f + 1 replicas are required totolerate f faults). Moreover, total ordering of messages is needed by mostclassical protocols to provide strong consistency in both agreement and executionphases. Research has improved throughput of the execution phase by introducingconcurrency using modern multicore infrastructures in recent years. However,improvements to the agreement phase remains an open area.

    Byzantine Fault Tolerant systems use State Machine Replication to tolerate awide range of faults. The approach uses leader based consensus algorithms for thedeterministic execution of service on all replicas to make sure all correct replicasreach same state. For this purpose, several algorithms have been proposed toprovide total ordering of messages through an elected leader. Usually, a singleleader is considered to be a bottleneck as it cannot provide the desired throughputfor real-time software services. In order to achieve a higher throughput there is aneed for a solution which can execute multiple consensus rounds concurrently.

    We present a solution that enables multiple consensus rounds in parallel bychoosing multiple leaders. By enabling concurrent consensus, our approach canexecute several requests in parallel. In our approach we incorporate applicationspecific knowledge to split the total order of events into multiple partial orderswhich are causally consistent in order to ensure safety. Furthermore, a dependencycheck is required for every client request before it is assigned to a particular leaderfor agreement. This methodology relies on optimistic prediction of dependenciesto provide higher throughput. We also propose a solution to correct the course ofexecution without rollbacking if dependencies were wrongly predicted.

    Our evaluation shows that in normal cases this approach can achieve upto 100% higher throughput than conventional approaches for large numbers ofclients. We also show that this approach has the potential to perform better incomplex scenarios

  • 42. Abolhassani, M.
    et al.
    Chan, T. -HH.
    Chen, Fei
    KTH.
    Esfandiari, H.
    Hajiaghayi, M.
    Mahini, H.
    Wu, X.
    Beating ratio 0.5 for weighted oblivious matching problems2016Ingår i: Leibniz International Proceedings in Informatics, LIPIcs, Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing , 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    We prove the first non-trivial performance ratios strictly above 0.5 for weighted versions of the oblivious matching problem. Even for the unweighted version, since Aronson, Dyer, Frieze, and Suen first proved a non-trivial ratio above 0.5 in the mid-1990s, during the next twenty years several attempts have been made to improve this ratio, until Chan, Chen, Wu and Zhao successfully achieved a significant ratio of 0.523 very recently (SODA 2014). To the best of our knowledge, our work is the first in the literature that considers the node-weighted and edge-weighted versions of the problem in arbitrary graphs (as opposed to bipartite graphs). (1) For arbitrary node weights, we prove that a weighted version of the Ranking algorithm has ratio strictly above 0.5. We have discovered a new structural property of the ranking algorithm: if a node has two unmatched neighbors at the end of algorithm, then it will still be matched even when its rank is demoted to the bottom. This property allows us to form LP constraints for both the node-weighted and the unweighted oblivious matching problems. As a result, we prove that the ratio for the node-weighted case is at least 0.501512. Interestingly via the structural property, we can also improve slightly the ratio for the unweighted case to 0.526823 (from the previous best 0.523166 in SODA 2014). (2) For a bounded number of distinct edge weights, we show that ratio strictly above 0.5 can be achieved by partitioning edges carefully according to the weights, and running the (unweighted) Ranking algorithm on each part. Our analysis is based on a new primal-dual framework known as matching coverage, in which dual feasibility is bypassed. Instead, only dual constraints corresponding to edges in an optimal matching are satisfied. Using this framework we also design and analyze an algorithm for the edge-weighted online bipartite matching problem with free disposal. We prove that for the case of bounded online degrees, the ratio is strictly above 0.5. 

  • 43.
    Aboode, Adam
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Anomaly Detection in Time Series Data Based on Holt-Winters Method2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I dagens värld ökar mängden insamlade data för varje dag som går, detta är en trend som sannolikt kommer att fortsätta. Samtidigt ökar även det potentiella värdet av denna data tack vare ständig utveckling och förbättring utav både hårdvara och mjukvara. För att utnyttja de stora mängder insamlade data till att skapa insikter, ta beslut eller träna noggranna maskininlärningsmodeller vill vi försäkra oss om att vår data är av god kvalité. Det finns många definitioner utav datakvalité, i denna rapport fokuserar vi på noggrannhetsaspekten.

    En metod som kan användas för att säkerställa att data är av god kvalité är att övervaka inkommande data och larma när anomalier påträffas. Vi föreslår därför i denna rapport en metod som, baserat på historiska data, kan detektera anomalier i tidsserier när nya värden anländer. Den föreslagna metoden består utav två delar, dels att förutsäga nästa värde i tidsserien genom Holt-Winters metod samt att jämföra residualen med en estimerad normalfördelning.

    Vi utvärderar den föreslagna metoden i två steg. Först utvärderas noggrannheten av de, utav Holt-Winters metod, förutsagda punkterna för olika storlekar på indata. I det andra steget utvärderas prestandan av anomalidetektorn när olika metoder för att estimera variansen av residualernas distribution används. Resultaten indikerar att den föreslagna metoden i de flesta fall fungerar bra för detektering utav punktanomalier i tidsserier med en trend- och säsongskomponent. I rapporten diskuteras även möjliga åtgärder vilka sannolikt skulle förbättra prestandan hos den föreslagna metoden.

  • 44.
    Abou Zliekha, M.
    et al.
    Damascus University/Faculty of Information Technology.
    Al Moubayed, Samer
    Damascus University/Faculty of Information Technology.
    Al Dakkak, O.
    Higher Institute of Applied Science and Technology (HIAST).
    Ghneim, N.
    Higher Institute of Applied Science and Technology (HIAST).
    Emotional Audio-Visual Arabic Text to Speech2006Ingår i: Proceedings of the XIV European Signal Processing Conference (EUSIPCO), Florence, Italy, 2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    The goal of this paper is to present an emotional audio-visual. Text to speech system for the Arabic Language. The system is based on two entities: un emotional audio text to speech system which generates speech depending on the input text and the desired emotion type, and un emotional Visual model which generates the talking heads, by forming the corresponding visemes. The phonemes to visemes mapping, and the emotion shaping use a 3-paramertic face model, based on the Abstract Muscle Model. We have thirteen viseme models and five emotions as parameters to the face model. The TTS produces the phonemes corresponding to the input text, the speech with the suitable prosody to include the prescribed emotion. In parallel the system generates the visemes and sends the controls to the facial model to get the animation of the talking head in real time.

  • 45.
    Abraham, Mark James
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Beräkningsbiofysik. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Murtola, T.
    Schulz, R.
    Páll, Szilárd
    KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Smith, J. C.
    Hess, Berk
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Beräkningsbiofysik. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Lindahl, Erik
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Beräkningsbiofysik. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Gromacs: High performance molecular simulations through multi-level parallelism from laptops to supercomputers2015Ingår i: SoftwareX, ISSN 2352-7110, Vol. 1-2, s. 19-25Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    GROMACS is one of the most widely used open-source and free software codes in chemistry, used primarily for dynamical simulations of biomolecules. It provides a rich set of calculation types, preparation and analysis tools. Several advanced techniques for free-energy calculations are supported. In version 5, it reaches new performance heights, through several new and enhanced parallelization algorithms. These work on every level; SIMD registers inside cores, multithreading, heterogeneous CPU-GPU acceleration, state-of-the-art 3D domain decomposition, and ensemble-level parallelization through built-in replica exchange and the separate Copernicus framework. The latest best-in-class compressed trajectory storage format is supported.

  • 46. Abrahamsson, H
    et al.
    Hagsand, Olof
    KTH, Skolan för datavetenskap och kommunikation (CSC), Teoretisk datalogi, TCS.
    Marsh, Ian
    TCP over high speed variable capacity links: A simulation study for bandwidth allocation2002Konferensbidrag (Refereegranskat)
    Abstract [en]

     New optical network technologies provide opportunities for fast, controllable bandwidth management. These technologies can now explicitly provide resources to data paths, creating demand driven bandwidth reservation across networks where an applications bandwidth needs can be meet almost exactly. Dynamic synchronous Transfer Mode (DTM) is a gigabit network technology that provides channels with dynamically adjustable capacity. TCP is a reliable end-to-end transport protocol that adapts its rate to the available capacity. Both TCP and the DTM bandwidth can react to changes in the network load, creating a complex system with inter-dependent feedback mechanisms. The contribution of this work is an assessment of a bandwidth allocation scheme for TCP flows on variable capacity technologies. We have created a simulation environment using ns-2 and our results indicate that the allocation of bandwidth maximises TCP throughput for most flows, thus saving valuable capacity when compared to a scheme such as link over-provisioning. We highlight one situation where the allocation scheme might have some deficiencies against the static reservation of resources, and describe its causes. This type of situation warrants further investigation to understand how the algorithm can be modified to achieve performance similar to that of the fixed bandwidth case.

  • 47. Abrahamsson, M.
    et al.
    Sundberg, Johan
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH, Musikakustik.
    Subglottal pressure variation in actors’ stage speech2007Ingår i: Voice and Gender Journal for the Voice and Speech Trainers Association / [ed] Rees, M., VASTA Publishing , 2007, s. 343-347Kapitel i bok, del av antologi (Refereegranskat)
  • 48.
    Abrahamyan, Lilit
    et al.
    University of Amsterdam.
    Schaap, Jorrit A.
    Hoekstra, Alfons G.
    Shamonin, Denis
    M.A.Box, Frieke
    Van der Geest, Rob J.
    H.C. Reiber, Johan
    M.A. Sloot, Peter
    A Problem Solving Environment for Image-Based Computational Hemodynamics2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    We introduce a complete problem solving environment designed for pulsatile flows in 3D complex geometries, especially arteries. Three-dimensional images from arteries, obtained from e.g. Magnetic Resonance Imaging, are segmented to obtain a geometrical description of the arteries of interest. This segmented artery is prepared for blood flow simulations in a 3D editing tool, allowing to define in- and outlets, to filter and crop part of the artery, to add certain structures ( e.g. a by-pass, or stents ), and to generate computational meshes as input to the blood flow simulators. Using dedicated fluid flow solvers the time dependent blood flow in the artery during one systole is computed. The resulting flow, pressure and shear stress fields are then analyzed using a number of visualization techniques. The whole environment can be operated from a desktop virtual reality system, and is embedded in a Grid computing environment.

  • 49.
    Abreu, Rodrigo
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Numerisk analys, NA (stängd 2012-06-30).
    Jansson, Niclas
    KTH, Skolan för datavetenskap och kommunikation (CSC), Numerisk analys, NA (stängd 2012-06-30).
    Hoffman, Johan
    KTH, Skolan för datavetenskap och kommunikation (CSC), Numerisk analys, NA (stängd 2012-06-30).
    Adaptive computation of aeroacoustic sources for a rudimentary landing gear using lighthill's analogy2011Ingår i: 17th AIAA/CEAS AeroacousticsConference 2011: 32nd AIAA Aeroacoustics Conference, 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    We present our simulation results for the benchmark problem of the ow past a Rudimentary Landing Gear (RLG) using a General Galerkin (G2) nite element method, also referred to as Adaptive DNS/LES. In G2 no explicit subgrid model is used, instead the compuational mesh is adaptively re ned with respect to an a posteriori error es-timate of a quantity of interest in the computation, in this case the drag force on the RLG. Turbulent boundary layers are modeled using a simple wall layer model with the shear stress at walls proportional to the skin friction, which here is assumed to be small and, therefore, can be approximated by zero skin friction. We compare our results with experimental data and other state of the art computations, where we nd good agreement in sound pressure levels, surface velocities and ow separation. We also compare with detailed surface pressure experimental data where we nd largely good agreement, apart from some local dierences for which we discuss possible explanations.

  • 50.
    Abu Nijmeh, Jonas
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Catalan Canales, Diego
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Prokrastinering i form av medieanvändning: En jämförelsestudie kring kön och sysselsättning2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Prokrastinering har sedan länge varit ett problem som många möter. Vare sig det handlar om skolarbete, träning eller något annat har de flesta individer upplevt att de medvetet skjutit upp en uppgift till ett senare tillfälle. Detta fenomen har under senare tid integrerats i vårt samhälle på ett oftast negativt vis. I vårt mediecentrerade samhälle blir vi allt mer uppkopplade och nuförtiden har nästan hela Sveriges befolkning tillgång till internet. Tekniken har medfört många möjligheter men har även öppnat upp för nya sätt att prokrastinera.

    Denna studie ämnade undersöka prokrastinering i form av medieanvändning hos en stor målgrupp bestående av folk i alla åldrar. Vi ämnade att ta reda på eventuella skillnader i prokrastineringsvanor mellan könen men också bland yrkesarbetande och studerande. Tidigare forskning har redan visat att prokrastinering skiljer sig med ålder och sysselsättning. Mot bakgrund av detta söker vi att besvara frågan: Vilka medier använder personer när de prokrastinerar samt på vilka tekniska plattformar sker detta? För att besvara denna forskningsfråga utförde vi en förstudie på en mindre grupp för att få ett bättre förstånd för vilka frågor som var relevanta i sammanhanget. Denna förstudie låg sedan till grund för en enkätstudie med 91 deltagare.

    Resultatet visade tydliga skillnader mellan både män och kvinnor och mellan studerande och yrkesarbetande. Skillnader gällande både medieanvändning och prokrastineringsvanor kunde ses där vissa skillnader var mer märkbara än andra. Resultatet bekräftar tidigare studier i flera aspekter och ger oss en viss insikt om hur olika prokrastineringsvanor kan se ut.

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