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  • 48901.
    Wu, Dan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Programvaruteknik och Datorsystem, SCS.
    Context Knowledge Base for Ontology Integration2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Ontologi-integration är en process för att matcha och sammanfoga två ontologier för att t.ex. generera en ny ontologi, och därmed skapa digitala tjänster och produkter. Aktuella tekniker för ontologi- integration, som används för information och kunskapsintegration, är inte tillräckligt kraftfulla för att hantera semantiska och pragmatiska heterogeniteter. På grund av heterogeniteter, har ontologi- matchning och -integration visat sig utgöra ett komplext problem, särskilt när avsikten är att göra processen automatisk.

    Denna avhandling behandlar problemet med att integrera heterogena ontologier; för det första genom att undersöka kontexten för ontologi-integrationen, för det andra genom att bygga en kunskapsbas för kontexten, och för det tredje genom att tillämpa denna kunskapsbas. Mer specifikt bidrar avhandlingen med CKB-OI-metoden för ontologi-integration, vilken innehåller:

    1)      En metod för att bygga en kontextkunskapsbas, genom att extrahera sammanhang och kontextuell information från ontologier i ett ontologi-förvar för att förbättra ontologi-integrationen.

    2)      En metod för att förfina resultatet av ontologi-integration med hjälp av kontextkunskapsbasen och för att utöka kontextreglerna i kunskapsbasen.

    I metod nr. 1 identifieras kontexten genom att undersöka innehållet och metadata för de ontologier, som ska integrereras. Kontexten innehåller information som beskriver integrationen, till exempel domän och syfte för varje ontologi, samt element som ingår i respektive ontologi. Kontexten  modelleras med kriterier, såsom metadata och element för ontologierna i förvaret. Den kontextuella informationen extraheras och integreras med användning av en integrationsprocess med icke-överträdelsekontroll. Kontextkunskapsbasen byggs utav kontext samt kontextuell information. Eftersom kunskapsbasen är byggd av återanvända ontologier för att ge ytterligare information till ontologi-integrationen inom samma kontext, så är det mycket möjligt att kontextkunskapsbasen kommer att förbättra det tidigare integrationsresultatet.

    En metod för att identifiera domänen för en ontologi föreslås också, för att hjälpa till att bygga och använda kontextkunskapsbasen. Eftersom metoden tar hänsyn till de semantiska och pragmatiska heterogeniteterna hos ontologier, och använder en enkel ontologi för att representera en domän, så ökar detta arbete det semantiska värdet av kontextkunskapsbasen.

    I metod nr. 2 tillämpas kontextkunskapsbasen på resultatet av en ontologi-integrationsprocess med icke-överträdelsekontroll, vilket i sin tur resulterar i ett ontologisnitt. Den kontextuella informationen extraheras från kontextkunskapsbasen och appliceras sedan på ontologisnittet för att förbättra integrationsresultatet. Icke-överträdelsekontrollen i integrationsprocessen justeras och används på nytt. Dessutom utökas kontextkunskapsbasen med perspektivregler, med vilka de olika vyerna av ontologier i en gemensam kontext bevaras och återanvänds i framtida ontologi-integrationer.

    Resultaten av CKB-OI metoden är: 1) en kontextkunskapsbas med regler som avser semantiska och pragmatiska kunskaper om en ontologi-integration; 2) ett kontextuellt ontologisnitt (COI) med ett förfinat resultat jämfört med ontologisnittet (OI) och 3) en utökad kontextkunskapsbas med olika vyer av båda ontologier. För utvärderingen har ontologier från Ontology Alignment Evaluation Initiative (OAEI) samt ontologisökmotorerna Swoogle och Watson använts för att testa de föreslagna metoderna. Resultaten visar att kontextkunskapsbasen kan användas för förbättring av heterogena ontologi-integrationer. Följaktligen tillhandahåller kontextkunskapsbasen semantiska och pragmatiska kunskaper för att integrera ontologier. Dessutom visar resultaten att ontologi-integrationer, utökade med kontextkunskapsbaser, innehåller mer kunskap, utan att motsäga de ontologier som ingår i våra exempel.

  • 48902.
    Wu, Dan
    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.
    An approach to match and integrate ontology using ontology repository and rule base2012Ingår i: WEBIST 2012 - Proceedings of the 8th International Conference on Web Information Systems and Technologies, 2012, s. 434-439Konferensbidrag (Refereegranskat)
    Abstract [en]

    There exist a lot of ontologies that together can enrich knowledge within one or several related domains, thereby supporting the development of advanced services on the semantic web. This requires matching and integrating ontologies. This paper introduces an ontology matching process that handles the heterogeneities. The result is an intersection of the two original ontologies. An ontology repository stores the original ontologies and the matching results. A rule base is designed to integrate stored ontologies and the matching results with metadata, which is describing the interpretation of these ontologies and ontology matching results. The contribution of our approach is the semantic violation check which results in an ontology intersection that validates in the original ontologies. The metadata is applied with rules to integrate the ontologies so that the ontology and the matching results can be reused.

  • 48903.
    Wu, Dan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Håkansson, Anne
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Applying a Knowledge Based System for Metadata Integration for Data Warehouses2010Ingår i: KNOWLEDGE-BASED AND INTELLIGENT INFORMATION AND ENGINEERING SYSTEMS / [ed] Setchi R; Jordanov I; Howlett RJ; Jain LC, 2010, Vol. 6279, s. 60-69Konferensbidrag (Refereegranskat)
    Abstract [en]

    Data warehouses is a typical example of distributed systems where diverse tools and platforms need to communicate to understand each other. For the communication, metadata integration is significant. Seamless metadata interchange improves the data quality and the system effectiveness. Metadata standards exist, for instance, Common Warehouse MetaModel (CWM), which have enhanced the metadata integration. However, it is far from solving the problem of metadata integration in data warehouse environment. This paper proposes an approach to apply a knowledge-based system that supports the metadata integration. By utilizing the knowledge of software engineers on Common Warehouse MetaModels and the metadata interchange models, the knowledge-based system can give metadata interchange model suggestions. Such a knowledge-based system intends to partly automate the metadata integration to improve the efficiency and the quality of metadata integration in data warehouses.

  • 48904. Wu, Dazhong
    et al.
    Rosen, David W.
    Wang, Lihui
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Schaefer, Dirk
    Cloud-based design and manufacturing: A new paradigm in digital manufacturing and design innovation2015Ingår i: Computer-Aided Design, ISSN 0010-4485, E-ISSN 1879-2685, Vol. 59, s. 1-14Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cloud-based design manufacturing (CBDM) refers to a service-oriented networked product development model in which service consumers are enabled to configure, select, and utilize customized product realization resources and services ranging from computer-aided engineering software to reconfigurable manufacturing systems. An ongoing debate on CBDM in the research community revolves around several aspects such as definitions, key characteristics, computing architectures, communication and collaboration processes, crowdsourcing processes, information and communication infrastructure, programming models, data storage, and new business models pertaining to CBDM. One question, in particular, has often been raised: is cloud-based design and manufacturing actually a new paradigm, or is it just "old wine in new bottles"? To answer this question, we discuss and compare the existing definitions for CBDM, identify the essential characteristics of CBDM, define a systematic requirements checklist that an idealized CBDM system should satisfy, and compare CBDM to other relevant but more traditional collaborative design and distributed manufacturing systems such as web- and agent-based design and manufacturing systems. To justify the conclusion that CBDM can be considered as a new paradigm that is anticipated to drive digital manufacturing and design innovation, we present the development of a smart delivery drone as an idealized CBDM example scenario and propose a corresponding CBDM system architecture that incorporates CBDM-based design processes, integrated manufacturing services, information and supply chain management in a holistic sense.

  • 48905.
    Wu, Desheng
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Företagsekonomiska institutionen. University of Chinese Academy of Sciences, China.
    Cui, Yiwen
    Disaster early warning and damage assessment analysis using social media data and geo-location information2018Ingår i: Decision Support Systems, ISSN 0167-9236, E-ISSN 1873-5797, Vol. 111, s. 48-59Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Societies are confronted with destructive natural disasters of increasing frequency. Social networks are playing an increasingly important role as early warning systems, aiding with rapid disaster assessment and post-disaster recovery. There is a need for both the public and disaster-relief agencies to better understand how social media can be utilized to assess and respond to natural disasters. However, existing research on the role of social media in society's response to natural disasters is neither holistic nor systematic. In this study, we conduct a hierarchical multiscale analysis based on multiple data resources, combining social media data, economic losses, and geo-information. We verify the role played by social media before, during, and after a natural disaster. We investigate whether the combination of social media and geo-location information can contribute to a more efficient early warning system and help with disaster assessment. This paper draws attention to the fact that during a disaster, citizens turn to social media and the majority of tweets contain information about the hurricane and/or its impact with negative sentiment. We demonstrate that the severity of damage in one area is positively correlated with the intensity of disaster-related activity. Meanwhile, the coastal areas and areas with close proximity to Hurricane center tend to suffer from higher losses during a disaster. Our findings explore the role played by social media from individuals in affected populations and how they respond to unfolding natural disasters. Results hold significance with regard to providing timely assistance for both official institutions and netizens.

  • 48906.
    Wu, Desheng Dash
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Företagsekonomiska institutionen. University of Chinese Academy of Sciences, China.
    Selling to the Socially Interactive Consumer: Order More or Less?2015Ingår i: ieee transactions on systems man cybernetics systems, ISSN 2168-2216, Vol. 45, nr 3, s. 399-410Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper studies the newsvendor problem in the presence of consumer behavior, specifically, social interaction. We show that deterministic consumer valuation on products derived from social interaction can be an advantage for firms. This paper examines the implications of random consumer product valuation and a lower threshold number of subscribers to the proposed deal. Several implications have been yielded.

  • 48907.
    Wu, Dexiang
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Företagsekonomiska institutionen.
    Robust Decision Support System for Asset Assessment and Management2017Ingår i: IEEE Systems Journal, ISSN 1932-8184, E-ISSN 1937-9234, Vol. 11, nr 3, s. 1486-1491Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We address asset classification and portfolio selection in this paper. Surprisingly, money managers find that the market volatility becomes more frequent as more advanced innovations are applied in the financial system. For example, the high-frequency trading may amplify the deviation on U.S. stock market [1], [2]. Therefore, a reliable method to appraise the asset performance is extremely important to portfolio managers, regulators, and individual investors. One alternative approach to achieve this goal is data envelopment analysis (DEA). Asset performance was ranked from both self-and peer-evaluation perspectives. Specifically, we extended the cross-efficiency analysis in DEA that uses row and column means to portfolio selection and identify different types of asset set. This classification process can help investors to construct a more robust portfolio. Numerical experiments based on S&P500 showed that the portfolio with cross-efficiency analysis can generate better Sharpe ratios during the period of financial crisis in 2008.

  • 48908.
    Wu, Dong
    et al.
    Dept. of Electronics and Computer Science University of Southampton.
    Al Hashimi, Bashir M.
    Dept. of Electronics and Computer Science University of Southampton.
    Eles, Petru Ion
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, ESLAB - Laboratoriet för inbyggda system.
    Scheduling and Mapping of Conditional Task Graph for the Synthesis of Low Power Embedded Systems2003Ingår i: Design Automation and Test in Europe DATE 2003 Conference,2003, Munich, Germany: IEEE Computer Society Press , 2003, s. 90-Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes a new Dynamic Voltage Scaling (DVS) technique for embedded systems expressed as Conditional Task Graphs (CTGs). The idea is to identify and exploit the available worst case slack time, taking into account the conditional behaviour of CTGs. Also we examine the effect of combining a genetic algorithm based mapping with the DVS technique for CTGs and show that further energy reduction can be obtained. The techniques have been tested on a number of CTGs including a real-life example. The results show that the DVS technique can be applied to CTGs with energy saving up to 24%. Furthermore it is shown that savings of up to 51% are achieved by considering DVS during the mapping.

  • 48909.
    Wu, Dong
    et al.
    Dept. of Electronics and Computer Science University of Southampton.
    Al Hashimi, Bashir M.
    Dept. of Electronics and Computer Science University of Southampton.
    Eles, Petru Ion
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, ESLAB - Laboratoriet för inbyggda system.
    Scheduling and Mapping of Conditional Task Graph for the Synthesis of Low Power Embedded Systems2003Ingår i: IEE Proceedings - Computers and digital Techniques, ISSN 1350-2387, E-ISSN 1359-7027, Vol. 150, nr 5, s. 302-312Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A dynamic voltage scaling (DVS) technique for embedded systems expressed as conditional task graphs (CTGs) is described. The idea is to identify and exploit the available worst case slack time, taking into account the conditional behaviour of CTGs. Also the effect of combining a genetic algorithm based mapping with the DVS technique is examined and it is shown that further energy reduction can be achieved. The techniques are tested on a number of CTGs including a real-life example. The results show that the DVS technique can be applied to CTGs with an energy saving of up to 24%. Furthermore, it is shown that savings of up to 51% are achieved by considering during the mapping optimisation. Finally, the impact of communications and communication link selection on the scheduling and mapping technique is investigated and results are reported.

  • 48910.
    Wu, Dong
    et al.
    School of Electronics and Computer Science University of Southampton.
    Al-Hashimi, Bashir M.
    School of Electronics and Computer Science University of Southampton.
    Schmitz, Marcus T.
    School of Electronics and Computer Science University of Southampton.
    Eles, Petru Ion
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, ESLAB - Laboratoriet för inbyggda system.
    Power-Composition Profile Driven Co-Synthesis with Power Management Selection for Dynamic and Leakage Energy Reduction2005Ingår i: 8th Euromicro Conference on Digital System Design DSD2005,2005, Porto, Portugal: IEEE Computer Society Press , 2005, s. 34-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Recent research has shown that the combination of dynamic voltage scaling (DVS) and adaptive body biasing (ABB) yields high energy reductions in embedded systems. Nevertheless, the implementation of DVS and ABB requires a significant system cost, making it less attractive for many small systems. In this paper we demonstrate that it is possible to reduce this system cost and to achieve comparable energy saving to that obtained using combined DVS and ABB scheme through a co-synthesis methodology which is aware of the tasks' power-composition profile (the ratio of the dynamic power to the leakage power). In particular, the presented methodology performs a power management selection at the architectural level, i.e., it decides upon which processing elements to be equipped with which power management scheme (DVS, ABB, or combined DVS and ABB) - with the aim to achieve high energy savings at a reduced implementation cost. The proposed technique maps, schedules, and voltage scales applications specified as task graphs with timing constraints. Detailed experiments including a real-life benchmark are conducted to demonstrate the effectiveness of the proposed methodology.

  • 48911.
    Wu, Hao
    et al.
    The University of Sydney, Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    B-Alarm: An Entropy Based Burst Traffic Prediction Approach for Ethernet Switches in Data Centers2013Ingår i: High Performance Computing and Communications & 2013 IEEE International Conference on Embedded and Ubiquitous Computing (HPCC_EUC), 2013 IEEE 10th International Conference on, IEEE conference proceedings, 2013Konferensbidrag (Refereegranskat)
  • 48912.
    Wu, Haotian
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Prototype a solution for multi-track premium music score web player2014Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Den nuvarande kommersiella versionen av ScorX multi-track premium music score(MPMS) har dåligt stöd för mobila enheter och det kan medföra extra kostnader att göra så att produkten stödjer mobila enheter. Projektet syftar till att fokusera på att utveckla en MPMS baserat på en webbaserad och plattformsoberoende teknik. Bolagets kommersiella version bygger på Adobe Flash Player. En utredning genomförs och resultatet visar att en möjlig lösning finns i att använda Web Audio API och Adobe Edge Animate där det redan finns en prototyp som bygger på denna lösning. Studien av detta visar att en alternativ lösning för att göra systemet kompatibelt med mobila enheter kan vara en skräddarsydda native-versioner för respektive mobil hårdvaruplattform och Haxe för övriga stationära och mobila enheter.

    När prototypen var byggd kördes en serie tester för att utvärdera både Flash player lösningen och HTML5-lösningen. Det visar sig att Flash player fortfarande kommer att vara ett första val för stationära enheter i nuvarande fas eftersom den är mer stabil med en ganska tillfredsställande prestanda, medan HTML5-lösningen fungerar bättre i mobila enheter. Den huvudsakliga nackdelen med HTML5-lösning ligger på utförandet av ljudmotorn (dvs Web Audio API) i stället för animeringen av motorn. Eftersom er och er stora webbläsare har full supportWeb Audio API, kommer ljudmotorn prestera ännu bättre framöver. Den framtida utvecklingen av ScorX flerspårig premium musik poäng bör därfor inriktas på HTML5 och ursprungliga programmet om det behövs.

  • 48913.
    Wu, Hong
    Blekinge Tekniska Högskola, Sektionen för teknik, Avdelningen för programvarusystem.
    An Experiment on the Suitability of RAM for Test Case Design2009Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    To perform software testing at the early stages of software development process can save the cost and effort on finding and fixing defects. As the first stage of software development process, requirements engineering has been moved away from project-initiated requirements engineering towards requirements-initiated development in the last decade. This leads new challenges that it demands support for handling the requirements continually come in from multiple stakeholders on multiple abstraction levels instead of some specific customers. Requirements Abstraction Model was developed as a hierarchical abstraction method for requirements management, which is enable product management to leverage their resources and select requirements for implementation without overloading the organization. RAM was validated in industry on the usability for requirements management, but there is no evaluation for RAM on software testing. This thesis presents an empirical study with a goal of evaluating the suitability of RAM for test case design in respective of efficiency and effectiveness by the comparison with IEEE Std. 830 which is a standard of the traditional requirements specification. For achieving the goal of this study, a controlled experiment is conducted based on the refinement on an initial experiment planning, and is operated with twenty developers in industry in China. Analysis of the collected data from the experiment indicates that RAM has a similar effectiveness as using the requirements in IEEE Std. 830 format, while RAM is more efficient for test case design. Therefore, RAM is suitable for test case design, and has better performance than IEEE Std. 830 comprehensively in view of both efficiency and effectiveness.

  • 48914. Wu, Huayong
    et al.
    Zonta, D.
    Pozzi, M.
    Zanon, P.
    Ceriotti, M.
    Mottola, Luca
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Picco, G. P.
    Guna, S.
    Murphy, A. L.
    Corrà, M.
    Wireless Sensors for Permanent Monitoring of Heritage Buildings2010Konferensbidrag (Refereegranskat)
  • 48915. Wu, Jian
    et al.
    Bao, Yanan
    Miao, Guowang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Niu, Zhisheng
    Base station sleeping and power control for bursty traffic in cellular networks2014Ingår i: 2014 IEEE International Conference on Communications Workshops, ICC 2014, 2014, s. 837-841Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we study sleeping and power control of a single-cell cellular network with bursty traffic. The base station (BS) sleeps whenever the system is empty, and wakes up when N users are assembled. The service capacity of the BS in the active mode is controlled through its transmitting power. The total power consumption and average delay for bursty traffic that follows the Interrupted Poisson Process (IPP) are analyzed. We discuss when the BS should sleep and the impact of traffic burstiness on it. The impact of the sleeping threshold and the transmitting power on the system performance is also investigated. The numerical results show that given the average traffic load, the more bursty the traffic is, the less the total power is consumed, while the delay performance of the more bursty traffic is better only under certain circumstances.

  • 48916. Wu, Jinsong
    et al.
    Bisio, Igor
    Gniady, Chris
    Hossain, Ekram
    Valla, Massimo
    Li, Haibo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    CONTEXT-AWARE NETWORKING AND COMMUNICATIONS: PART 12014Ingår i: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 52, nr 6, s. 14-15Artikel i tidskrift (Övrigt vetenskapligt)
  • 48917.
    Wu, Junfeng
    et al.
    Zhejiang Univ, Coll Control Sci & Engn, Hangzhou 310027, Peoples R China..
    Shi, Guodong
    Australian Natl Univ, Res Sch Engn, Canberra, ACT 0200, Australia..
    Anderson, Brian D. O.
    Australian Natl Univ, Res Sch Engn, Canberra, ACT 0200, Australia.;Hangzhou Dianzi Univ, Hangzhou 310000, Zhejiang, Peoples R China..
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. Royal Inst Technol, Sch Elect Engn, ACCESS Linnaeus Ctr, S-10044 Stockholm, Sweden..
    Kalman Filtering Over Fading Channels: Zero-One Laws and Almost Sure Stabilities2018Ingår i: IEEE Transactions on Information Theory, ISSN 0018-9448, E-ISSN 1557-9654, Vol. 64, nr 10, s. 6731-6742Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we investigate probabilistic stability of Kalman filtering over fading channels modeled by *-mixing random processes, where channel fading is allowed to generate non-stationary packet dropouts with temporal and/or spatial correlations. Upper/lower almost sure (a.s.) stabilities and absolutely upper/lower a.s. stabilities are defined for characterizing the sample-path behaviors of the Kalman filtering. We prove that both upper and lower a.s. stabilities follow a zero-one law, i.e., these stabilities must happen with a probability either zero or one, and when the filtering system is one-step observable, the absolutely upper and lower a.s. stabilities can also be interpreted using a zero-one law. We establish general stability conditions for (absolute) upper and lower a.s. stabilities. In particular, with one-step observability, we show the equivalence between absolutely a.s. stabilities and a.s. ones, and necessary and sufficient conditions in terms of packet arrival rate are derived; for the so-called non-degenerate systems, we also manage to give a necessary and sufficient condition for upper a.s. stability.

  • 48918.
    Wu, Liming
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Matematiska och systemtekniska institutionen.
    Li, Kai
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Matematiska och systemtekniska institutionen.
    Water Simulating in Computer Graphics2007Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [en]

    Fluid simulating is one of the most difficult problems in computer graphics. On the other hand, water appears in our life very frequently. This thesis focuses on water simulating. We have two main methods to do this in the thesis: the first is wave based water simulating; Sine wave summing based and Fast Fourier Transform based methods are all belong to this part. The other one is physics based water simulating. We make it based on Navier-Stokes Equation and it is the most realistic animation of water. It can deal with the boundary and spray which other method cannot express. Then we put our emphasis on implement by the physics method using Navier-Stokes Equation.

  • 48919.
    Wu, Po-Han
    et al.
    Department of Engineering Science, National Cheng Kung University, Taiwan..
    Hwang, Gwo-Jen
    National Taiwan University of Science and Technology, Taiwan.
    Milrad, Marcelo
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för datavetenskap, fysik och matematik, DFM.
    Ke, Hui-Ru
    ´Department of Information and Learning Technology, National University of Tainan, Taiwan.
    Huang, Yueh-Min
    Graduate Institute of Digital Learning and Education, National Taiwan University of Science and Technology.
    An innovative concept map approach for improving students’ learning performance with an instant feedback mechanism2012Ingår i: British Journal of Educational Technology, ISSN 0007-1013, E-ISSN 1467-8535, Vol. 43, nr 2, s. 217-232Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Concept maps have been widely employed for helping students organise their knowledgeas well as evaluating their knowledge structures in a wide range of subject matters.Although researchers have recognised concept maps as being an important educationaltool, past experiences have also revealed the difficulty of evaluating the correctness of aconcept map. It usually takes days or weeks for teachers to manually evaluate theconcept maps developed by students; consequently, the students cannot receive timelyfeedback from the teachers, which not only affects their learning schedules, but alsosignificantly influences the students’ learning achievements. In this paper, a computerbasedconcept map-oriented learning strategy with real-time assessment and feedback isproposed in order to cope with the problems mentioned above. Our approach providesimmediate evaluation of concept maps and gives also real-time feedback to the students.An experiment has been conducted to evaluate the effectiveness of this new strategy incomparison with the conventional computer-based concept map approach. It is foundthat our innovative approach can be significantly beneficial to promote learningachievements as well as the learning attitudes of students.

  • 48920.
    Wu, Qihui
    et al.
    College of Communications Engineering PLA University of Science and Technology, Nanjing.
    Ding, Guoro
    College of Communications Engineering PLA University of Science and Technology, Nanjing.
    Du, Zhiyong
    PLA Academy of National Defense Information, Wuhan.
    Sun, Youming
    National Digital Switching System Engineering & Technological Research Center, Zhengzhou.
    Jo, Minho
    Department of Computer and Information Science, Korea University.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    A Cloud-Based Architecture for the Internet of Spectrum Devices (IoSD) over Future Wireless Networks2016Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 4, s. 2854-2862Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dramatic increase in data rates in wireless networks has caused radio spectrum usage to be an essential and critical issue. Spectrum sharing is widely recognized as an affordable, near-term method to address this issue. This article first characterizes the new features of spectrum sharing in future wireless networks, including heterogeneity in sharing bands, diversity in sharing patterns, crowd intelligence in sharing devices, and hyper-densification in sharing networks. Then, to harness the benefits of these unique features and promote a vision of spectrum without bounds and networks without borders, this article introduces a new concept of the Internet of Spectrum Devices (IoSD) and develops a cloud-based architecture for IoSD over future wireless networks, with the prime aim of building a bridging network among various spectrum monitoring devices (SMDs) and massive spectrum utilization devices (SUDs), and enabling a highly-efficient spectrum sharing and management paradigm for future wireless networks. Furthermore, this article presents a systematic tutorial on the key enabling techniques of the IoSD, including big spectrum data analytics, hierarchal spectrum resource optimization, and quality of experience (QoE)- oriented spectrum service evaluation. In addition, the unresolved research issues are also presented.

  • 48921.
    Wu, Taodi
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ding, Shuyang
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Analysing Real-Time Traffic in Wormhole-Switched On-ChipNetworks2016Självständigt arbete på avancerad nivå (magisterexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    With the increasing demand of computation capabilities, many-core processors are gain-ing more and more attention. As a communication subsystem many-core processors, Network-on-Chip (NoC) draws a lot of attention in the related research fields. A NoC is used to deliver messages among different cores. For many applications, timeliness is of great importance, especially when the application has hard real-time requirements. Thus, the worst-case end-to-end delays of all the messages passing through a NoC should be concerned. Unfortunately, there is no existing analysis tool that can support multiple NoC architectures as well as provide a user-friendly interface.This thesis focuses on a wormhole switched NoC using different arbitration policies which are Fixed Priority (FP) and Round Robin (RR) respectively. FP based arbitration policy includes distinct and shared priority based arbitration policies. We have developed a timing analysis tool targeting the above NoC designs. The Graphical User Interface (GUI) in the tool can simplify the operation of users. The tool takes characteristics of flow sets as input, and returns results regarding the worst-case end-to-end delay of each flow. These results can be used to assist the design of real-time applications on the corre-sponding platform.A number of experiments have been generated to compare different arbitration mecha-nisms using the developed tool. The evaluation focuses on the effect of different param-eters including the number of flows and the number of virtual-channels in a NoC, and the number of hops of each flow. In the first set of experiment, we focus on the schedulabil-ity ratio achieved by different arbitration policies regarding the number of flows. The sec-ond set of experiments focus on the comparison between NoCs with different number of virtual-channels. In the last set of experiments, we compare different arbitration mecha-nisms with respect to the worst-case end-to-end latencies.

  • 48922.
    Wu, Wu
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Adapting Information-Centric Networking to Small Sensor Nodes for Heterogeneous IoT Networks2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    IoT-industrin har upplevt en snabb utveckling på senare år och det beräknas snart vara möjligt att ansluta miljarder saker till Internet. Det finns emellertid fortfarande vissa flaskhalsar när det gäller till exempel kostnader och effektförbrukning. I jämförelse med det traditionella nätverk kan nya IoT-nät beskrivas som mer informationscentrerade än värddatorcentrerade. Därför bestämmer vi oss i detta arbete för att undersöka möjligheten att tillämpa Content Centric Network (CCN) för att addressera utmaningarna i IoT-nät.

    Denna rapport presenterar huvudsakligen hur man implementerar CCN för trådlösa sensornätverk (WSN) och utvärderar lösningar, bland annat baserat på en grundlig jämförelse mellan MQTT och MQTT-SN.

  • 48923.
    Wu, Xiangyi
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Medieteknik och interaktionsdesign, MID.
    Use animations to support knowledge transfer built on the understanding of the non-experts’ mental model2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Kunskapsvisualisering som en ny filial av visualiseringsvetenskap grundades av Burkhard [1] år 2004. I hans teori nämndes animering som ett av de stora visuella formaten för kunskapsöverföring. Det saknas dock ytterligare forskning om dess inverkan på kunskapsöverföring. Syftet med denna studie är att förstå nyckelegenskaper som utgör den mentala modellen för icke-experter på domänkunskaper. Därefter undersöks hur animeringar stöder kunskapsöverföring till icke-experter. I denna studie används hemautomatiseringsplanering som ett fall för att utforska de egenskaper som bäst utgör en bra animation för kunskapsöverföring. Resultaten visade att icke-experters generella uppmärksamhet placerades på orsak och effekt relationer av en typisk automatisk belysningsstyrning och icke-experter hade missuppfattningar möjligen på grund av olika livserfarenheter, kunskapsbakgrund, informationsvaghet och övertygelse. Händelsegmenteringen i icke-experters mentalmodell användes för att styra animationsdesign som resulterade i högre uppfattad klarhet, mindre missuppfattningar vid kunskapsöverföring till icke-experter. Dessutom visade våra resultat från förklarande observation att animeringar har potential att underlätta samverkande kunskapsöverföring och beslutsprocess.

  • 48924.
    Wu, Xue
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Matematiska och systemtekniska institutionen.
    Can Google Earth enhance Business Intelligence?: Exploring innovative uses of a new GIS tool2007Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [en]

    We are facing a period that coming into information time, which forced us to live in a new living style. It seems that every business movement is related with information transformation. When computers are used to deal with business data, we begin to search a way to make digital data into refined format information in order to let people to understand. This change results in a changing of business forms. For example, e-services refer to provide a certain service or play function on line, which has the tendency to replace the place of traditional service. How this kind of service can be developed remains a question mark to us.

    The challenge of e-service is how to get different functions into integration. This thesis begins to research it focusing the point view of GIS (Geography Information System). Take Google earth as an example to illustrate how GIS is being used and what possible future uses of it can be developed. By exploring its use in data collecting, and analyzing, the possible applications in business world can be obviously released.

  • 48925.
    Wu, Yongchao
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Zhang, Jiawei
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Name Resolution Information Distribution in NetInf2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Information-Centric Networking (ICN) is a different architecture from today's Internet, which is host-centric. In ICN, content is requested by the names of content objects instead of network or host addresses. This feature allows for a number of advantages, such as in-network caching and request aggregation. Network of Information (NetInf) is an ICN architecture. It is an overlay on TCP/IP, which translates content object names to locators or IP addresses. NetInf is designed to facilitate initial deployment and migration from today's networks to ICN.

    In an ICN network, content can be cached at numerous locations giving a client the possibility to retrieve content from a number of available sources. In order to retrieve a content object, a client does a lookup in a Name Resolution Service (NRS) to resolve the content name into a set of locators where the content is stored. By distributing the location information of content objects from the NRS to NetInf nodes in the network the lookup time and overhead caused by the lookup messages can be reduced. Hence resulting in better end-user experience and more efficient network utilization. In this thesis, two methods to distribute location information of content objects in a NetInf network have been proposed and evaluated against a reference model where the location information is hosted centrally in an NRS. The effectiveness of the proposed methods has been evaluated by running simulations on a NetInf simulator (built on OMNeT++) that was built during the course of this project.

    Evaluation results show that the proposed methods reduce the lookup/name resolution latency of content objects. The results also compare the overhead caused by each one of the proposed methods in terms of network utilization. We also show the results that the network topology has an impact on the effectiveness of the proposed methods and therefore is a factor that needs due consideration in deciding which method is suitable when.

  • 48926.
    Wu, Yuan-Zhong
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för datavetenskap (DV).
    Ottosson, Alexander
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för datavetenskap (DV).
    Visualiseringsverktyg för röstkommunikation2014Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Saab har utvecklat en produkt, Remote Tower, som tillåter flygledningen att fjärrstyra en flygplats, det vill säga att övervaka och kontrollera en flygplats på distans. Ett viktigt verktyg för flygledarna är VCS, Voice Communication System, som är Saabs egna röstkommunikationssystem, där både radio- och telefonkommunikation ingår. VCS används för att kommunicera med piloter och markpersonal på flygplatsen. Målet är att i framtiden kunna fjärrstyra fler flygplatser samtidigt, och då finns ett behov att visualisera de inkommande samtalen från de olika flygplatserna i realtid. Detta för att undvika ett scenario där flygledaren missar ett samtal. Ett system har utvecklats för just detta ändamål vars huvuduppgift är att visualisera de samtal som VCS producerar. Systemet kan hantera tre flygplatser samtidigt, och varje samtal kan spelas upp genom att klicka på de inkommande samtalen.

  • 48927.
    Wu, Yucheng
    Social Wireless Network Secure Identification.
    A secure mobile social network2012Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Mobile social networks are a new trend to improve the quality of our life, so they should not bring any extra burden to users. The users should not anymore be worried how to set up a secure complex password and memorize it to prove their identities. The Generic Bootstrapping Architecture is used in this thesis as a novel way of authentication. The GBA protocol allows to generate and share cryptographic keys between a mobile phone and third party service providers using the operator as intermediary. These keys are generated transparently without any user interaction. In a traditional mobile social network, an Internet connection is compulsory but we believe this should not be a barrier in the future. An ad-hoc network may be used to communicate in a private group of friends. Thus, users need to be capable of verifying membership assertions and generating offline invitations for new friends without a connection to the social network server. Our implementation uses SAML assertions to certify group memberships and offline invitations. Beside these security solutions, a real mobile social network has been implemented, using the REST framework for communication and databases for storing information both on the client and the social network server.

  • 48928. Wu, Z.
    et al.
    Cao, J.
    Mao, Bo
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Wang, Y.
    Semi-SAD: Applying semi-supervised learning to shilling attack detection2011Ingår i: RecSys - Proc. ACM Conf. Recomm. Syst., 2011, s. 289-292Konferensbidrag (Refereegranskat)
    Abstract [en]

    Collaborative filtering (CF) based recommender systems are vulnerable to shilling attacks. In some leading e-commerce sites, there exists a large number of unlabeled users, and it is expensive to obtain their identities. Existing research efforts on shilling attack detection fail to exploit these unlabeled users. In this article, Semi-SAD, a new semi-supervised learning based shilling attack detection algorithm is proposed. Semi-SAD is trained with the labeled and unlabeled user profiles using the combination of naïve Bayes classifier and EM-λ, augmented Expectation Maximization (EM). Experiments on MovieLens datasets show that our proposed Semi-SAD is efficient and effective.

  • 48929.
    Wu, Zhenzhi
    et al.
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska fakulteten. Beijing Institute Technology, Peoples R China.
    Gong, Chen
    Beijing Institute Technology, Peoples R China.
    Liu, Dake
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska fakulteten. Beijing Institute Technology, Peoples R China.
    Computational Complexity Analysis of FEC Decoding on SDR Platforms2017Ingår i: Journal of Signal Processing Systems, ISSN 1939-8018, E-ISSN 1939-8115, Vol. 89, nr 2, s. 209-224Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The computational complexity evaluation is necessary for software defined Forward Error Correction (FEC) decoders. However, currently there are a limited number of literatures concerning on the FEC complexity evaluation using analytical methods. In this paper, three high efficient coding schemes including Turbo, QC-LDPC and Convolutional code (CC) are investigated. The hardware-friendly decoding pseudo-codes are provided with explicit parallel execution and memory access procedure. For each step of the pseudo-codes, the parallelism and the operations in each processing element are given. Based on it the total amount of operations is derived. The comparison of the decoding complexity among these FEC algorithms is presented, and the percentage of each computation step is illustrated. The requirements for attaining the evaluated results and reference hardware platforms are provided. The benchmarks of state-of-the-art SDR platforms are compared with the proposed evaluations. The analytical FEC complexity results are beneficial for the design and optimization of high throughput software defined FEC decoding platforms.

  • 48930. Wubs, Fred W.
    et al.
    Thies, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Matematiska institutionen.
    A Robust Two-Level Incomplete Factorization for (Navier-)Stokes Saddle Point Matrices2011Ingår i: SIAM Journal on Matrix Analysis and Applications, ISSN 0895-4798, E-ISSN 1095-7162, Vol. 32, nr 4, s. 1475-1499Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a new hybrid direct/iterative approach to the solution of a special class of saddle point matrices arising from the discretization of the steady incompressible Navier-Stokes equations on an Arakawa C-grid. The two-level method introduced here has the following properties: (i) it is very robust, even close to the point where the solution becomes unstable; (ii) a single parameter controls fill and convergence, making the method straightforward to use; (iii) the convergence rate is independent of the number of unknowns; (iv) it can be implemented on distributed memory machines in a natural way; (v) the matrix on the second level has the same structure and numerical properties as the original problem, so the method can be applied recursively; (vi) the iteration takes place in the divergence-free space, so the method qualifies as a "constraint preconditioner"; (vii) the approach can also be applied to Poisson problems. This work is also relevant for problems in which similar saddle point matrices occur, for instance, when simulating electrical networks, where one has to satisfy Kirchhoff's conservation law for currents.

  • 48931. Wuhib, Fetahi
    et al.
    Dam, Mads
    CNS.
    Stadler, Rolf
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    A Gossiping Protocol for Detecting Global Threshold Crossings2010Ingår i: IEEE Transactions on Network and Service Management (TNSM), Vol. 7, nr 1Artikel i tidskrift (Refereegranskat)
  • 48932. Wuhib, Fetahi
    et al.
    Dam, Mads
    RISE., Swedish ICT, SICS.
    Stadler, Rolf
    RISE., Swedish ICT, SICS.
    Gossiping for threshold detection2009Konferensbidrag (Refereegranskat)
  • 48933. Wuhib, Fetahi
    et al.
    Stadler, Rolf
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Distributed monitoring and resource management for large cloud environments2011Konferensbidrag (Refereegranskat)
  • 48934. Wuhib, Fetahi
    et al.
    Stadler, Rolf
    RISE., Swedish ICT, SICS.
    Lindgren, H.
    Dynamic Resource Allocation with Management Objectives: Implementation for an OpenStack Cloud2012Konferensbidrag (Refereegranskat)
  • 48935. Wuhib, Fetahi
    et al.
    Stadler, Rolf
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Spreitzer, Mike
    A Gossip Protocol for Dynamic Resource Management in Large Cloud Environments2012Ingår i: IEEE Transactions on Network and Service management (TNSM), Vol. 9Artikel i tidskrift (Refereegranskat)
  • 48936. Wuhib, Fetahi
    et al.
    Stadler, Rolf
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Spreitzer, Mike
    Gossip-based Resource Management for Cloud Environments2010Konferensbidrag (Refereegranskat)
  • 48937.
    Wuhib, Fetahi Zebenigus
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsnät.
    Distributed Monitoring and Resource Management for Large Cloud Environments2010Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Over the last decade, the number, size and complexity of large-scale networked systems has been growing fast, and this trend is expected to accelerate. The best known example of a large-scale networked system is probably the Internet, while large datacenters for cloud services are the most recent ones. In such environments, a key challenge is to develop scalable and adaptive technologies for management functions. This thesis addresses the challenge by engineering several protocols  for distributed monitoring and resource management that are suitable for large-scale networked systems. First, we present G-GAP, a gossip-based protocol we developed for continuous monitoring of aggregates that are computed from device variables. We prove the robustness of this protocol to node failures and validate, through simulations, that its estimation accuracy does not change with increasing size of the monitored system under certain conditions. Second, we present TCA-GAP, a tree-based protocol, and TG-GAP, a gossip-based protocol for the purpose of monitoring threshold crossings of aggregates. For both protocols, we prove correctness properties and show, again through simulations, that both protocols are efficient, by showing that their overhead is at least two orders of magnitude smaller than that of a na\"ive approach, for cases where the monitored aggregate is sufficiently far from the threshold. Third, we present a gossip-based protocol for resource management in cloud environments. The protocol allocates CPU and memory resources to sites that are hosted by the cloud. We prove that the resource allocation computed by the protocol converges exponentially fast to an optimal allocation, for cases where sufficient memory is available. Through simulations, we show that the quality of the resource allocation approaches that of an ideal system when the total memory demand decreases significantly below the memory capacity of the entire system. In addition, we validate that the quality of the allocation does not change with increasing the number of hosted sites and machines, for the case where both metrics are scaled proportionally. Finally, we compare two approaches (tree-based and gossip-based) to engineering protocols for distributed management, for the case of real-time monitoring. Results of our simulation studies indicate that, regardless of the system size and failure rates in the monitored system, gossip protocols incur a significantly larger overhead than tree-based protocols for achieving the same monitoring quality (e.g., estimation accuracy or detection delay).

  • 48938. Wulf, O.
    et al.
    Arras, Kai Oliver
    KTH, Tidigare Institutioner, Numerisk analys och datalogi, NADA.
    Christensen, Henrik
    KTH, Tidigare Institutioner, Numerisk analys och datalogi, NADA.
    Wagner, B.
    2D mapping of cluttered indoor environments by means of 3D perception2004Ingår i: Proceedings - IEEE International Conference on Robotics and Automation, 2004, nr 4, s. 4204-4209Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a combination of a 3D laser sensor and a line-base SLAM algorithm which together produce 2D line maps of highly cluttered indoor environments. The key of the described method is the replacement of commonly used 2D laser range sensors by 3D perception. A straightforward algorithm extracts a virtual 2D scan that also contains partially occluded walls. These virtual scans are used as input for SLAM using line segments as features. The paper presents the used algorithms and experimental results that were made in a former industrial bakery. The focus lies on scenes that are known to be problematic for pure 2D systems. The results demonstrate that mapping indoor environments can be made robust with respect to both, poor odometry and clutter.

  • 48939.
    Wulff, Annegrete
    Statistics Denmark.
    Eyes Wide Shut - Or Using Eye Tracking Technique to Test a Website2007Ingår i: International Journal of Public Information Systems, ISSN 1653-4360, Vol. 3, nr 1, s. 1-12Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This presentation provides an introduction to the technique called "Eye Tracking" which Statistics Denmark has recently used to test the usability of its website user interface. Eye tracking is a tool used to analyse "human - computer" interaction. The user's eye movements and fixation time are both registered when this technique is used. However, whether the person actually perceives what the eyes are fixed on is not documented. Statistics Denmark has tested this method on ten users who were asked to carry out particular tasks on the website. It is open to discussion whether the method is strong enough to be used independently. Some of the results were quite persuasive and supported the comments from other users. However, we suggest that eye tracking should not be the only method employed, but it should be used in combination with more traditional usability methods such as, "think aloud" and follow-up interviews.

  • 48940.
    Wursthorn, Amelie
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för datavetenskap, fysik och matematik, DFM.
    Determination of Call Graphs in Web Service Structures2012Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This work is part of a project which addresses a detection of the most suitable Webservice for the needs of a particular end user within service oriented architecture (SOA).As of today a research group located at Karlsruhe University of Applied Sciences,Germany, and Linnæus University, Sweden developed a framework which obtainsknowledge about quality of services. Thereby this framework offers the possibility toregister several Web services and guarantees the routing of the communication betweenthem through an Enterprise Service Bus (ESB) implementation developed by this group.The project raises several issues that have to be solved in order to reach the aim ofproviding a framework which selects the most suitable services based on non-functionalcriteria like response time or reliability.Web services call each other to provide their own functionality.The first aim of this work is to redirect released requests (sub-requests) which areinitiated by previous requests (sub-requests), or to manipulate specific data,respectively. A sub-request should then call a specified service which had prior to thisbeen selected by the framework.The next and main part of this work deals with providing data which keepinformation about the relation between requests and those requests released by a Webservice as a reaction of these initial calls. This data is the basis input for later calculatingof call graphs. This issue leads to further questions: The information about Web servicecalls is not reported by the standard log output of the host server. The approach for asolution has to define a way to record the Web service requests and their dependenciesamong each other.For verifying the concept an implementation will demonstrate the successful result.

  • 48941. Wyatt, Jeremy L.
    et al.
    Aydemir, Alper
    KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Centrum för Autonoma System, CAS. KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP.
    Brenner, Michael
    Hanheide, Marc
    Hawes, Nick
    Jensfelt, Patric
    KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Centrum för Autonoma System, CAS. KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP.
    Kristan, Matej
    Kruijff, Geert-Jan M.
    Lison, Pierre
    Pronobis, Andrzej
    KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP. KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Centrum för Autonoma System, CAS.
    Sjöö, Kristoffer
    KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Centrum för Autonoma System, CAS. KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP.
    Vrecko, Alen
    Zender, Hendrik
    Zillich, Michael
    Skocaj, Danijel
    Self-Understanding and Self-Extension: A Systems and Representational Approach2010Ingår i: IEEE T AUTON MENT DE, ISSN 1943-0604, Vol. 2, nr 4, s. 282-303Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There are many different approaches to building a system that can engage in autonomous mental development. In this paper, we present an approach based on what we term self-understanding, by which we mean the explicit representation of and reasoning about what a system does and does not know, and how that knowledge changes under action. We present an architecture and a set of representations used in two robot systems that exhibit a limited degree of autonomous mental development, which we term self-extension. The contributions include: representations of gaps and uncertainty for specific kinds of knowledge, and a goal management and planning system for setting and achieving learning goals.

  • 48942.
    Wyke, Oskar
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    User Centered Design for Persons with Disabilities – How persons with cerebral palsy can be included in the design process.2011Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Användarcentrerad design är ett ramverk byggt på metoder som syftar till att inkludera användaren i designprocessen. När ett system, som ska användas av personer med allvarliga funktionsnedsättningar designas, introduceras ett antal unika svårigheter.

    Detta examensarbete undersöker vilka särskilda faktorer som måste tas i beaktande då en design för ögonstyrd interaktion skapas samt hur användare kan inkluderas trots närvaron av allvarliga funktionsnedsättningar.

    Personer från tre habiliteringscenter i stockholmsområdet inkluderades i studien som implementerades som en iterativ designprocess där metoder, vanliga inom användarcentrerad design, tillämpades.

    Resultatet av studien indikerar att många välkända metoder inom användarcentrerad design kan användas för att inkludera användare med Cerebral Pares. Fokus flyttas något från användaren till personer i dennes omgivning. För att åstadkomma hög användbarhet måste systemet tillhandahålla möjligheten till individuella anpassningar av färger, storlekar och placering av objekten på skärmen. En tvåstegsmetod, som minskar antalet ofrivilliga val, presenteras också.

  • 48943.
    Wynen, Daan
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Convolutional Kernel Networks for Action Recognition in Videos2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    While convolutional neural networks (CNNs) have taken the lead for many learning tasks, action recognition in videos has yet to see this jump in performance. Many teams are working on the issue but so far there is no definitive answer how to make CNNs work well with video data. Recently, introduced convolutional kernel networks, a special case of CNNs which can be trained layer by layer in an unsupervised manner. This is done by approximating a kernel function in every layer with finite-dimensional descriptors. In this work we show the application of the CKN training to video, discuss the adjustments necessary and the influence of the type of data presented to the networks as well as the number of filters used.

  • 48944. Wyrembelski, Rafael F.
    et al.
    Bjelakovic, Igor
    Oechtering, Tobias J.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Boche, Holger
    Optimal Coding Strategies for Bidirectional Broadcast Channels Under Channel Uncertainty2010Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 58, nr 10, s. 2984-2994Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bidirectional relaying is a promising approach to improve the performance in wireless networks such as sensor, ad-hoc, and even cellular systems. Bidirectional relaying applies to three-node networks, where a relay establishes a bidirectional communication between two other nodes using a decode-and-forward protocol. First, the two nodes transmit their messages to the relay which decodes them. Then, the relay broadcasts a re-encoded message in such a way that both nodes can decode their intended message using their own message as side information. We consider uncertainty in the channel state information (CSI) and assume that all nodes only know that the channel over which the transmission takes place is from a pre-specified set of channels. In this work, we concentrate on the second phase, which is called the compound bidirectional broadcast channel. We present a robust coding strategy which enables reliable communication under channel uncertainty and show that this strategy actually achieves the compound capacity. Further, we analyze scenarios where either the receivers or the transmitter have perfect CSI. We show that CSI at the receivers does not affect the maximal achievable rates, while CSI at the transmitter improves the capacity region. A numerical example and a game-theoretic interpretation complete this work.

  • 48945.
    Wzorek, Mariusz
    Linköpings universitet, Institutionen för datavetenskap, UASTECH – Teknologier för autonoma obemannade flygande farkoster. Linköpings universitet, Tekniska högskolan.
    Selected Aspects of Navigation and Path Planning in Unmanned Aircraft Systems2011Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Unmanned aircraft systems (UASs) are an important future technology with early generations already being used in many areas of application encompassing both military and civilian domains. This thesis proposes a number of integration techniques for combining control-based navigation with more abstract path planning functionality for UASs. These techniques are empirically tested and validated using an RMAX helicopter platform used in the UASTechLab at Linköping University. Although the thesis focuses on helicopter platforms, the techniques are generic in nature and can be used in other robotic systems.

    At the control level a navigation task is executed by a set of control modes. A framework based on the abstraction of hierarchical concurrent state machines for the design and development of hybrid control systems is presented. The framework is used to specify  reactive behaviors and for sequentialisation of control modes. Selected examples of control systems deployed on UASs are presented. Collision-free paths executed at the control level are generated by path planning algorithms.We propose a path replanning framework extending the existing path planners to allow dynamic repair of flight paths when new obstacles or no-fly zones obstructing the current flight path are detected. Additionally, a novel approach to selecting the best path repair strategy based on machine learning technique is presented. A prerequisite for a safe navigation in a real-world environment is an accurate geometrical model. As a step towards building accurate 3D models onboard UASs initial work on the integration of a laser range finder with a helicopter platform is also presented.

    Combination of the techniques presented provides another step towards building comprehensive and robust navigation systems for future UASs.

  • 48946.
    Wzorek, Mariusz
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Conte, Gianpaolo
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Rudol, Piotr
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Merz, Torsten
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, AUTTEK - Autonomous Unmanned Aerial Vehicle Research Group.
    Duranti, Simone
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, AUTTEK - Autonomous Unmanned Aerial Vehicle Research Group.
    Doherty, Patrick
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    From Motion Planning to Control - A Navigation Framework for an Autonomous Unmanned Aerial Vehicle2006Ingår i: Proceedings of the 21st Bristol UAV Systems Conference (UAVS), 2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of Unmanned Aerial Vehicles (UAVs) which can operate autonomously in dynamic and complex operational environments is becoming increasingly more common. While the application domains in which they are currently used are still predominantly military in nature, in the future we can expect wide spread usage in thecivil and commercial sectors. In order to insert such vehicles into commercial airspace, it is inherently important that these vehicles can generate collision-free motion plans and also be able to modify such plans during theirexecution in order to deal with contingencies which arise during the course of operation. In this paper, wepresent a fully deployed autonomous unmanned aerial vehicle, based on a Yamaha RMAX helicopter, whichis capable of navigation in urban environments. We describe a motion planning framework which integrates two sample-based motion planning techniques, Probabilistic Roadmaps and Rapidly Exploring Random Treestogether with a path following controller that is used during path execution. Integrating deliberative services, suchas planners, seamlessly with control components in autonomous architectures is currently one of the major open problems in robotics research. We show how the integration between the motion planning framework and thecontrol kernel is done in our system.

    Additionally, we incorporate a dynamic path reconfigurability scheme. It offers a surprisingly efficient method for dynamic replanning of a motion plan based on unforeseen contingencies which may arise during the execution of a plan. Those contingencies can be inserted via ground operator/UAV interaction to dynamically change UAV flight paths on the fly. The system has been verified through simulation and in actual flight. We present empirical results of the performance of the framework and the path following controller.

  • 48947.
    Wzorek, Mariusz
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Doherty, Patrick
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    A framework for reconfigurable path planning for autonomous unmanned aerial vehicles.2007Manuskript (preprint) (Övrig (populärvetenskap, debatt, mm))
  • 48948.
    Wzorek, Mariusz
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Doherty, Patrick
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Preliminary report: Reconfigurable path planning for an autonomous unmanned aerial vehicle2005Ingår i: Proceedings of the 24th Annual Workshop of the UK Planning and Scheduling Special Interest Group (PlanSIG), 2005Konferensbidrag (Refereegranskat)
  • 48949.
    Wzorek, Mariusz
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Doherty, Patrick
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Reconfigurable Path Planning for an Autonomous Unmanned Aerial Vehicle2006Ingår i: Proceedings of the Sixteenth International Conference on Automated Planning and Scheduling (ICAPS) / [ed] Derek Long, Stephen F. Smith, Daniel Borrajo, Lee McCluskey, AAAI Press, 2006, s. 438-441Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we present a motion planning framework for a fully deployed autonomous unmanned aerial vehicle which integrates two sample-based motion planning techniques, Probabilistic Roadmaps and Rapidly Exploring Random Trees. Additionally, we incorporate dynamic reconfigurability into the framework by integrating the motion planners with the control kernel of the UAV in a novel manner with little modification to the original algorithms. The framework has been verified through simulation and in actual flight. Empirical results show that these techniques used with such a framework offer a surprisingly efficient method for dynamically reconfiguring a motion plan based on unforeseen contingencies which may arise during the execution of a plan. The framework is generic and can be used for additional platforms.

  • 48950.
    Wzorek, Mariusz
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Doherty, Patrick
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning.
    Reconfigurable Path Planning for an Autonomous Unmanned Aerial Vehicle2006Ingår i: ICHIT 2006 - International Conference on Hybrid Information Technology,2006, 2006Konferensbidrag (Refereegranskat)
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