Ändra sökning
Avgränsa sökresultatet
928929930931932933934 46501 - 46550 av 49806
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 46501. Walters, Jamie
    et al.
    Kanter, Theo
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Savioli, Enrico
    A Distributed Framework for Organizing an Internet of Things2011Ingår i: The 3rd International ICST Conference on Mobile Lightweight Wireless Systems, 2011Konferensbidrag (Refereegranskat)
  • 46502. Walters, M. L.
    et al.
    Lohse, M.
    Hanheide, M.
    Wrede, B.
    Syrdal, D. S.
    Koay, K. L.
    Green, Anders
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Hüttenrauch, H.
    Dautenhahn, K.
    Sagerer, G.
    Severinson-Eklundh, Kerstin
    KTH, Skolan för datavetenskap och kommunikation (CSC), Medieteknik och interaktionsdesign, MID.
    Evaluating the Robot Personality and Verbal Behavior of Domestic Robots Using Video-Based Studies2014Ingår i: Household Service Robotics, Elsevier, 2014, s. 467-486Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Robots are increasingly being used in domestic environments and should be able to interact with inexperienced users. Human-human interaction and human-computer interaction research findings are relevant, but often limited because robots are different from both humans and computers. Therefore, new human-robot interaction (HRI) research methods can identify the design of robots suitable for inexperienced users. A video-based HRI (VHRI) methodology was used to carry out a multi-national HRI user study for the prototype domestic robot BIRON (BIelefeld RObot companioN). Previously, the VHRI methodology was used in constrained HRI situations, while in this study HRIs involved a series of events as part of a "home tour" scenario. Thus, the present chapter is the first study of this methodology in extended HRI contexts with a multi-national approach. Participants watched videos of the robot interacting with a human actor and rated two robot behaviors (Extrovert and Introvert). Participants' perceptions and ratings of the robot's behaviors differed with regard to both verbal interactions and person following by the robot. The study also confirms that the VHRI methodology provides a valuable means to obtain early user feedback, even before fully working prototypes are available. This can usefully guide the future design studies on robots, and associated verbal and non-verbal behaviors.

  • 46503.
    Waltzman, Rand
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Numerisk Analys och Datalogi, NADA.
    Winbladh, K.
    Alspaugh, T. A.
    Richardson, D. J.
    In the requirements lies the power2007Ingår i: 19th International Conference on Software Engineering and Knowledge Engineering, SEKE 2007, 2007, s. 185-190Konferensbidrag (Refereegranskat)
    Abstract [en]

    System requirements expressed as scenarios represent a rich source of knowledge about a system and the context in which it is used. This is because the scenarios are the result of extensive collaborative efforts of a wide variety of stakeholders and are in a form to which all can relate. Ideally, they serve to represent the interests of all stakeholders at each stage of the development life cycle. Our focus in this paper is system testing against requirements. In particular, we show (1) how the knowledge represented in scenarios (using ScenarioML) can be directly transformed into an operational knowledge base in a rule-based programming language (JESS), (2) how this knowledge base can be used in system testing to compute, manage, and compare expectations of system behavior to actual system behavior relative to the requirements, and (3) how this can be achieved in a manner that is transparent to all stakeholders. The power of this approach derives from the peculiarly reflective character of knowledge based systems and their explicit use of meta-information and meta-information processing. We demonstrate the viability of our approach by its application to the AquaLush system in which we detected several violations of the system's stated requirements.

  • 46504.
    Wan, Jiafu
    et al.
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Liu, Jianqi
    School of Information Engineering, Guangdong Mechanical & Electrical College, Guangzhou.
    Shao, Zehio
    School of Information Science and Technology, Chengdu University.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Imran, Muhammad Al
    College of Computer and Information Sciences, Almuzahmiyah, King Saud University.
    Zhou, Keliang
    School of Electrical Engineering and Automation, Jiangxi University of Science and Technology, Ganzhou.
    Mobile Crowd Sensing for Traffic Prediction in Internet of Vehicles2016Ingår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 16, nr 1, artikel-id 88Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The advances in wireless communication techniques, mobile cloud computing, automotive and intelligent terminal technology are driving the evolution of vehicle ad hoc networks into the Internet of Vehicles (IoV) paradigm. This leads to a change in the vehicle routing problem from a calculation based on static data towards real-time traffic prediction. In this paper, we first address the taxonomy of cloud-assisted IoV from the viewpoint of the service relationship between cloud computing and IoV. Then, we review the traditional traffic prediction approached used by both Vehicle to Infrastructure (V2I) and Vehicle to Vehicle (V2V) communications. On this basis, we propose a mobile crowd sensing technology to support the creation of dynamic route choices for drivers wishing to avoid congestion. Experiments were carried out to verify the proposed approaches. Finally, we discuss the outlook of reliable traffic prediction.

  • 46505.
    Wan, Jiafu
    et al.
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Tang, Shenglog
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Shu, Zhaogang
    Fujian Agriculture and Forestry University, Fuzhou, China, College of Computer and Information Sciences, Fujian Agriculture and Forestry University.
    Li, Di
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Wang, Shiyong
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Imran, Muhammad Al
    College of Computer and Information Sciences, Almuzahmiyah, King Saud University.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Software-Defined Industrial Internet of Things in the Context of Industry 4.02016Ingår i: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 16, nr 20, s. 7373-7380Artikel i tidskrift (Refereegranskat)
  • 46506.
    Wan, Jiafu
    et al.
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Tang, Shenglong
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Li, Di
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Cloud Robotics: Current Status and Open Issues2016Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 4, s. 2797-2807Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the development of cloud computing, big data and other emerging technologies, the integration of cloud technology and multi-robot systems makes it possible to design multi-robot systems with improved energy efficiency, high real-time performance and low cost. In order to address the potential of clouds in enhancing robotics for industrial systems, this paper describes the basic concepts and development process of cloud robotics and the overall architecture of these systems. Then, the major driving forces behind the development of cloud robotics are carefully analyzed from the point of view of cloud computing, big data, open source resources, robot cooperative learning, and network connectivity. Subsequently, the key issues and challenges in the current cloud robotic systems are proposed, and some possible solutions are also given. Finally, the potential value of cloud robotic systems in different practical applications is discussed.

  • 46507.
    Wan, Jiafu
    et al.
    Guangdong Provincial Key Laboratory of Precision Equipment and Manufacturing Technology, South China University of Technology.
    Tang, Shenglong
    School of Mechanical and Automotive Engineering, South China University of Technology.
    Li, Di
    School of Mechanical and Automotive Engineering, South China University of Technology.
    Wang, Shiyong
    School of Mechanical and Automotive Engineering, South China University of Technology.
    Liu, Chengliang
    School of Mechanical Engineering, Shanghai Jiao Tong University.
    Abbas, Haider
    Center of Excellence in Information Assurance, King Saud University.
    Vasilakos, Athanasios V.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    A Manufacturing Big Data Solution for Active Preventive Maintenance2017Ingår i: IEEE Transactions on Industrial Informatics, ISSN 1551-3203, E-ISSN 1941-0050, Vol. 13, nr 4, s. 2039-2047, artikel-id 7857790Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Industry 4.0 has become more popular due to recent developments in Cyber-Physical Systems (CPS), big data, cloud computing, and industrial wireless networks. Intelligent manufacturing has produced a revolutionary change, and evolving applications such as product lifecycle management are becoming a reality. In this paper, we propose and implement a manufacturing big data solution for active preventive maintenance in manufacturing environments. First, we provide the system architecture that is used for active preventive maintenance. Then, we analyze the method used for collection of manufacturing big data according to the data characteristics. Subsequently, we perform data processing in the cloud, including the cloud layer architecture, the real-time active maintenance mechanism, and the off-line prediction and analysis method. Finally, we analyze a prototype platform and implement experiments to compare the traditionally-used method with the proposed active preventive maintenance method. The manufacturing big data method used for active preventive maintenance has the potential to accelerate implementation of Industry 4.0.

  • 46508.
    Wan, Jiafu
    et al.
    School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou.
    Zhang, Daqiang
    School of Software Engineering, Tongji University, Shanghai.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Lloret, Jaime
    Department of Communications Polytechnic University of Valencia.
    Guest Editorial Special Issue on Cloud-Integrated Cyber-Physical Systems2017Ingår i: IEEE Systems Journal, ISSN 1932-8184, E-ISSN 1937-9234, Vol. 11, nr 1, s. 84-87Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    The advances in wireless sensor devices, big data, mobile computing, and cloud computing offer tremendous opportunities to realize the seamless integration between the physical world and the cyber space. The cloud-integrated cyberphysical system (CCPS) refers to virtually representing physical system components, such as sensors, actuators, robots, and other devices in clouds, accessing (e.g., monitoring, actuating and navigating) those physical components through their virtual representations, and processing/managing/controlling the large amount of data collected from physical components in clouds in a scalable, real-time, efficient, and reliable manner. Particularly, integrating cloud computing techniques (e.g., virtualization, elastic re-configuration, and multi-tenancy of resources) with CPS techniques (e.g., real-time scheduling, adaptive resource management and control, and embedded system design) will bring hope to advance the state of the art, and allow previously unachievable systems such as cloud-integrated internet of vehicles to be built, deployed, managed, and controlled effectively. This Special Issue on CCPS solicits the manuscripts on rigorous research on theories, methodologies, tools, and testbeds for CCPS. In this special issue, we selected ten papers. Each paper was carefully reviewed by peer review and guest editors. In the following, we will overview the accepted papers that reflect recent advances.

  • 46509.
    Wan, Miao
    et al.
    Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, China.
    Jönsson, Arne
    Linköpings universitet, Institutionen för datavetenskap, NLPLAB - Laboratoriet för databehandling av naturligt språk. Linköpings universitet, Tekniska högskolan.
    Wang, Cong
    Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, China.
    Li, Lixiang
    Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, China.
    Yang, Yixian
    Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, China.
    A Random Indexing Approach for Web User Clustering and Web Prefetching2012Ingår i: New Frontiers in Applied Data Mining: PAKDD 2011 International Workshops, Shenzhen, China, May 24-27, 2011, Revised Selected Papers / [ed] Longbing Cao, Joshua Zhexue Huang, James Bailey, Yun Sing Koh, Jun Luo, Springer Berlin/Heidelberg, 2012, s. 40-52Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper we present a novel technique to capture Web users’ behaviour based on their interest-oriented actions. In our approach we utilise the vector space model Random Indexing to identify the latent factors or hidden relationships among Web users’ navigational behaviour. Random Indexing is an incremental vector space technique that allows for continuous Web usage mining. User requests are modelled by Random Indexing for individual users’ navigational pattern clustering and common user profile creation. Clustering Web users’ access patterns may capture common user interests and, in turn, build user profiles for advanced Web applications, such as Web caching and prefetching. We present results from the Web user clustering approach through experiments on a real Web log file with promising results. We also apply our data to a prefetching task and compare that with previous approaches. The results show that Random Indexing provides more accurate prefetchings.

  • 46510.
    Wande, Johan
    et al.
    Högskolan Dalarna, Akademin Industri och samhälle, Informatik.
    Malm, Jens
    Högskolan Dalarna, Akademin Industri och samhälle, Informatik.
    Mått för att mäta kodkvalitet undersystemutvecklingsprocessen2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Viljan att hålla en hög kvalitet på den kod som skrivs vid utveckling av system och applikationerär inte något nytt i utvecklingsvärlden. Flera större företag använder sig av olika mått för attmäta kvaliteten på koden i sina system med målet att hålla en hög driftsäkerhet.Trafikverket är en statlig myndighet som ansvarar för driften av bland annat de system somhåller igång Sveriges järnvägsnät. Eftersom systemen fyller en viktig del i att säkra driften ochse till att tågpositioner, planering av avgångar och hantering av driftstörningar fungerar dygnetrunt för hela landet anser de att det är viktigt att sträva efter att hålla en hög kvalitet påsystemen.Syftet med det här examensarbetet var att ta reda på vilka mått som kan vara möjliga attanvända under systemutvecklingsprocessen för att mäta kvaliteten på kod och hur måtten kananvändas för att öka kvaliteten på IT-lösningar. Detta för att redan på ett tidigt stadie kunnamäta kvaliteten på den kod som skrivs i både befintliga och nyutvecklade system.Studien är en fallstudie som utfördes på Trafikverket, de olika måtten som undersöktes varcode coverage, nivån på maintainability index och antalet inrapporterade incidenter för varjesystem. Mätningar utfördes på sju av Trafikverkets system som i analysen jämfördes motantalet rapporterade incidenter. Intervjuer utfördes för att ge en bild över hur arbetssättet vidutveckling kan påverka kvaliteten. Genom litteraturstudier kom det fram ett mått som inte kundeanvändas praktiskt i det här fallet men är högst intressant, detta är cyclomatic complexity somfinns som en del av maintainability index men som även separat påverkar möjligheten att skrivaenhetstest.Resultaten av studien visar att måtten är användbara för ändamålet men bör inte användassom enskilda mått för att mäta kvalitet eftersom de fyller olika funktioner. Det är viktigt attarbetssättet runt utveckling genomförs enligt en tydlig struktur och att utvecklarna både harkunskap om hur man arbetar med enhetstest och följer kodprinciper för strukturen. Tydligakopplingar mellan nivån på code coverage och inflödet av incidenter kunde ses i de undersöktasystemen där hög code coverage ger ett lägre inflöde av incidenter. Ingen korrelation mellanmaintainability index och incidenter kunde hittas.

  • 46511.
    Wandel, Michael
    et al.
    University of Tübingen, Tübingen, Germany.
    Lilienthal, Achim J.
    University of Tübingen, Tübingen, Germany.
    Duckett, Tom
    Örebro universitet, Institutionen för teknik.
    Weimar, Udo
    University of Tübingen, Tübingen, Germany.
    Zell, Andreas
    University of Tübingen, Tübingen, Germany.
    Gas distribution in unventilated indoor environments inspected by a mobile robot2003Ingår i: Proceedings of the IEEE international conference on advanced robotics 2003, Coimbra, Portugal: University of Coimbra , 2003, Vol. 1-3, s. 507-512Konferensbidrag (Refereegranskat)
    Abstract [en]

    Gas source localisation with robots is usually performed in environments with a strong, unidirectional airflow created by artificial ventilation. This tends to create a strong, well defined analyte plume and enables upwind searching. By contrast, this paper presents experiments conducted in unventilated rooms. Here, the measured concentrations also indicate an analyte plume with, however, different properties concerning its shape, width, concentration profile and stability over time. In the results presented in this paper, two very different mobile robotic systems for odour sensing were investigated in different environments, and the similarities as well as differences in the analyte gas distributions measured are discussed.

  • 46512.
    Wandel, Michael
    et al.
    University of Tübingen, Tübingen, Germany.
    Lilienthal, Achim J.
    University of Tübingen, Tübingen, Germany.
    Zell, Andreas
    University of Tübingen, Tübingen, Germany.
    Weimar, Udo
    University of Tübingen, Tübingen, Germany.
    Mobile robot using different senses2002Ingår i: Proceedings of the international symposium on olfaction and electronic nose: ISOEN 2002, 2002, s. 128-129Konferensbidrag (Refereegranskat)
  • 46513.
    Wandel, Michael R.
    et al.
    University of Tübingen, Tübingen, Germany.
    Weimar, Udo
    University of Tübingen, Tübingen, Germany.
    Lilienthal, Achim J.
    University of Tübingen, Tübingen, Germany.
    Zell, Andreas
    University of Tübingen, Tübingen, Germany.
    Leakage localisation with a mobile robot carrying chemical sensors2001Ingår i: The 8th IEEE international conference on electronics, circuits and systems: ICECS 2001, Malta, Malta: IEEE, 2001, Vol. 3, s. 1247-1250, artikel-id 957441Konferensbidrag (Refereegranskat)
    Abstract [en]

    On the way to developing an electronic watchman one more sense, i.e. gas sensing facilities, are added to an autonomous mobile robot. For the gas detection, up to eight metal oxide sensors are operated using a commercial sensor system. The robot is able to move and navigate autonomously. The geometric information is extracted from laser range finder data. This input is used to build up an internal map while driving. Using the new sensor the localisation of a gas source in unventilated in-house environments is performed. First experiments in a one-dimensional case show a very good correlation between the peak and the gas source. The one-dimensional concentration profile is repeatedly recorded and stable for at least two hours. The two-dimensional experiments exhibit a circulation of the air within the room due to temperature and hence density effects. The latter is limiting the available recording time for the two-dimensional mapping

  • 46514.
    Wandel, Richard
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska fakulteten.
    En implementationsstudie av molntjänsters API2015Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Molntjänsterna Dropbox, Google Drive, Microsoft OneDrive och Box har implementerats. Syftet med rapporten är att observera vilka problem som kan uppstå vid implementationen av molntjänsterna, och hur dessa problem kan lösas. Resultatet blev att molntjänsterna hade liknande problem. Problemen som uppstod var att alla molntjänster förutom Google Drive kunde bara öppna filväljaren i en popup. Att ange rätt domännamn blev ett problem för flera molntjänster då det var olika hur mycket av URLen som behövde anges, vilket berodde på respektive API.

  • 46515.
    Wanderydz, Kristoffer
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    WEB APPLICATION SECURITY IN THE JAVA ENVIRONMENT2012Självständigt arbete på grundnivå (kandidatexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    This project focuses on web security. Some of the most famous vulnerabilities, known troubling web applications. Has been collected and analyzed. Each vulnerability collected in this project, was exploited and secured. Demon- strations from a web application prototype, developed for this project. Brings real examples for each vulnerability, both secured, and insecured. The proto- type ran on a Tomcat web server, and was developed with frameworks such as Web, Spring and Hibernate. Connected to one PostgreSQL data source. All vulnerabilities was successfully implemented in Spring framework, and they were all exploited. Every vulnerability was also secured, with different tools and methods from earlier mentioned frameworks. As a result, real examples from the prototype is used for demonstration in the project, both in a secure and an insecure state. The result views Spring as a framework with good security potential. Most of the Spring specific vulnerabilities, are logical design flaws from developers that can be avoided. Vulnerabilities not related to Spring, such as the one collected for this project. Could be prevented by using methods from the Spring framework or intelligent programming. Which leads to conclusions. Web applications are always exposed to attacks, no matter the framework in use. Creative hackers search to discover new vul- nerabilities, and update old ones all the time. Developers has a responsibility, towards the web applications users. Web applications can not just developed for normal use, but also against possible misuse. Frameworks with good reputation and well processed models, is a good ground for developing a secure application.

  • 46516. Wang, B.
    et al.
    Aihara, K.
    Kim, Beom Jun
    KTH, Skolan för datavetenskap och kommunikation (CSC), Beräkningsbiologi, CB. Sungkyunkwan University, South Korea .
    Immunization of geographical networks2009Ingår i: Complex Sciences: First International Conference, Complex 2009, Shanghai, China, February 23-25, 2009, Revised Papers, Part 2, Springer Berlin/Heidelberg, 2009, nr PART 2, s. 2388-2395Konferensbidrag (Refereegranskat)
    Abstract [en]

    We numerically investigate the epidemic spread phenomena and efficient immunization strategies on complex networks embedded in geometry. It is assumed that there exists an unavoidable time delay (we call it the detection time) between the actual infection and the beginning of immunization, and we implement two different immunization strategies: one is based on topological connection neighbors (CN) of the infected vertex and the other on geographical spatial neighbors (SN). It is found that the decrease of the detection time is very important for a successful immunization. Our results suggest that within the limitation of the network models considered here, in which the infection probability is assumed to decrease with the geographic distance, the simple SN strategy works almost equally or better than the CN strategy, especially when the detection time is longer.

  • 46517.
    Wang, Bin
    et al.
    School of Software, Shanghai Jiao Tong University.
    Qi, Zhengwei
    School of Software, Shanghai Jiao Tong University.
    Ma, Ruhui
    School of Software, Shanghai Jiao Tong University.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Guan, Haibing
    School of Software, Shanghai Jiao Tong University.
    A survey on data center networking for cloud computing2015Ingår i: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 91, s. 528-547Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Data Center Networks (DCNs) are an essential infrastructure that impact the success of cloud computing. A scalable and efficient data center is crucial in both the construction and operation of stable cloud services. In recent years, the growing importance of data center networking has drawn much attention to related issues including connective simplification and service stability. However, existing DCNs lack the necessary agility for multi-tenant demands in the cloud, creating poor responsiveness and limited scalability. In this paper, we present an overview of data center networks for cloud computing and evaluate construction prototypes based on these issues. We provide, specifically, detailed descriptions of several important aspects: the physical architecture, virtualized infrastructure, and DCN routing. Each section of this work discusses and evaluates resolution approaches, and presents the use cases for cloud computing service. In our attempt to build insight relevant to future research, we also present some open research issues. Based on experience gained in both research and industrial trials, the future of data center networking must include careful consideration of the interactions between the important aspects mentioned above

  • 46518.
    Wang, Biying
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    3D matrix-based visualization system of association rules2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    With the growing number of association rules, it becomes moreand more difficult for users to explore interesting rules due toits nature complexity. Studies base on human perception andintuition show that graphical representation could be a betterillustration of how to handle data by using the capabilities ofthe human visual system to seek information. The 3D matrixbasedapproach visualization system of association rules called3DMVS was implemented in present study. The main visualrepresentation employed the extended matrix-based approachwith rule-to-items mapping to general transaction data set. Anovel method merging rules and assigning weight is proposedto generate new rules to reduce the dimension of theassociation rules, which will help users to find more importantitems in the new rule. Additionally, several interactions suchas sorting, filtering, zoom and rotation, facilitate decisionmakers to explore the rules they are interested in variousaspects. Finally, various evaluation techniques have beenemployed to assess the system from a logical reasoning pointof view.

  • 46519.
    Wang, Biying
    et al.
    University of Jyväskylä, Jyväskylä, Finland.
    Zhang, Tingting
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informationssystem och -teknologi.
    Chang, Zheng
    University of Jyväskylä, Jyväskylä, Finland.
    Ristaniemi, Tapani
    University of Jyväskylä, Jyväskylä, Finland.
    Liu, Guohua
    Donghua University, Shanghai, China.
    3D Matrix-Based Visualization System of Association Rules2017Ingår i: IEEE CIT 2017 - 17th IEEE International Conference on Computer and Information Technology, IEEE, 2017, s. 357-362, artikel-id 8031499Konferensbidrag (Refereegranskat)
    Abstract [en]

    With the growing number of mining datasets, it becomes increasingly difficult to explore interesting rules because of the large number of resultant and its nature complexity. Studies on human perception and intuition show that graphical representation could be a better illustration of how to seek information from the data using the capabilities of human visual system. In this work, we present and implement a 3D matrix-based approach visualization system of association rules. The main visual representation applies the extended matrix-based approach with rule-to-items mapping to general transaction data set. A novel method merging rules and assigning weight is proposed in order to reduce the dimension of the association rules, which will help users to find more important items in the new rule. Furthermore, several interactions such as sorting, filtering, zoom and rotation, facilitate decision-makers to explore the rules which are of interest in various aspects. Finally, extensive evaluations have been conducted to assess the system from a logical reasoning point of view. 

  • 46520.
    Wang, Chao
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Matematiska och systemtekniska institutionen.
    Grail to XMI and Back2008Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats
    Abstract [en]

    Grail is an open source graph library, which is developed at the MSI of Växjö University, tools like the VizzAnalyzer and vizz3d use Grail for representing their internal structures.

    In this thesis, an adapter serializing and deserializing Grail graphs to and from XMI is introduced. XMI is short for XML Metadata Interchange; it is developed by the Object Management Group (OMG).

  • 46521.
    Wang, Chao
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Fan, Y.
    Thompson, J. S.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Poor, H. V.
    Shifted successive decode-and-forward relaying: Towards the optimal diversity-multiplexing tradeoff for a four-node cooperative network2010Ingår i: IEEE International Conference on Communications, 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, a novel cooperative diversity transmission protocol is proposed for a four-node network where a single-antenna source communicates with its intended Nantenna destination with the help of two K-antenna decode-and-forward (DF) relays. Without requiring complex coding strategies at the relays, a sufficiently strong or weak inter-relay channel, or destination-source feedback, the proposed shifted successive DF relaying (SSDFR) protocol asymptotically achieves the optimal diversity-multiplexing tradeoff performance the four-node network can provide.

  • 46522.
    Wang, Chao
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Fan, Y.
    Thompson, J. S.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Poor, H. V.
    Superposition-repetition-coded successive decode-and-forward relaying with limited destination-relay feedback2010Ingår i: IEEE Wireless Communications and Networking Conference, 2010, Vol. WCNCKonferensbidrag (Refereegranskat)
    Abstract [en]

    A novel cooperative diversity transmission protocol using two K-antenna decode-and-forward relays to take turns assisting in the communication between a single-antenna source and its intended N-antenna destination is studied. A (1+2?logK?)-bit destination-relay feedback signal is exploited to perform relay/antenna selection. Two different simple forwarding strategies are applied at the relays: one relay uses a superposition-coding strategy while the other relay uses a repetition-coding strategy. When the source's frame length is sufficiently large, the optimal diversity-multiplexing tradeoff of the four-node network can be achieved asymptotically if K = 3.

  • 46523.
    Wang, Chen
    et al.
    CSIRO, Australia.
    Ranjan, Rajiv
    CSIRO, Australia.
    Zhou, Xiangmin
    CSIRO, Australia.
    Mitra, Karan
    Saha, Suhit
    CSIRO, Australia.
    Meng, Meng
    CSIRO, Australia.
    Georgakopopulos, Dimitrios
    CSIRO, Australia.
    Wang, Lizhe
    Center for Earth Observation & Digital Earth, Chinese Academy of Sciences.
    Thew, Peter
    CSIRO, Australia.
    A Cloud-based Collaborative Video Story Authoring and Sharing Platform2012Ingår i: CSI Journal of Computing, ISSN 2277-7091, Vol. 1, nr 3, s. 66-76Artikel i tidskrift (Refereegranskat)
  • 46524.
    Wang, Cheng
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Liu, Changling
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Adopting DevOps in Agile: Challenges and Solutions2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Background. DevOps is a hot topic in recent years. It emphasizes the combination of development and operation. Agile is one of the most popular development methods, but Agile mainly focused on software development part, there is no more involvement in deployment and operations. In this case, many companies consider adopting DevOps in Agile to attempt to improve the situation.

    Objectives. The combination of two different technologies is bound to produce some challenges, whether it is for practitioners or researchers, it is very important to find these challenges and mitigate them, so this article aims to investigate the challenges of adopting DevOps in Agile, then through the systematic literature review and survey questionnaire to determine the corresponding mitigation strategy. Then, in order to detail understand the process of adopting DevOps in Agile, we use interview to research the real process of adopting DevOps in agile.

    Methods. According to our research question, we used the systematic literature review(SLR), survey questionnaire and interview as our research methodology. Through literature review, we collected data of adopting DevOps in Agile, and summary the challenges and its relevant mitigation strategies. Then survey questionnaire helped us linking the content of literature to the industry, and compare their difference. Through the interview, we explored the actual process of adopting DevOps in Agile in industry, and correspond the challenges to the actual process.

    Results. Our study summarized the software development process of adopting DevOps based on Agile and revealed 23 challenges and corresponding mitigation strategies. The report also compares the commonalities and gaps between the results from the literature and the findings of real-life adopting of DevOps challenges and mitigation strategies.

    Conclusions. In this article, we introduced the challenges and corresponding mitigation strategies for adopting DevOps based on agile and summarize the corresponding software development process. The obvious challenges and mitigation strategies were divided into four categories: 1) People 2) Project 3) Process 4) Organization, after which we conducted further discussions based on the actual conditions and compared the results of systematic literature review and the results of questionnaire to detail explore their difference.

  • 46525.
    Wang, Chihyu
    et al.
    Research Center for Information Technology Innovation, Academia Sinica, Taipei.
    Wei, Hungyu Hung-Yu
    National Taiwan University.
    Bennis, Mehdi
    University of Oulu.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Game-theoretic approaches in heterogeneous networks2015Ingår i: Game Theory Framework Applied to Wireless Communication Networks, Hershey, PA: IGI Global, 2015, s. 88-102Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Improving capacity and coverage is one of the main issues in next-generation wireless communication. Heterogeneous networks (HetNets), which is currently investigated in LTE-Advanced standard, is a promising solution to enhance capacity and eliminate coverage holes in a cost-efficient manner. A HetNet is composed of existing macrocells and various types of small cells. By deploying small cells into the existing network, operators enhance the users' quality of service which are suffering from severe signal degradation at cell edges or coverage holes. Nevertheless, there are numerous challenges in integrating small cells into the existing cellular network due to the characteristics: unplanned deployment, intercell interference, economic potential, etc. Recently, game theory has been shown to be a powerful tool for investigating the challenges in HetNets. Several game-theoretic approaches have been proposed to model the distributed deployment and self-organization feature of HetNets. In this chapter, the authors first give an overview of the challenges in HetNets. Subsequently, the authors illustrate how game theory can be applied to solve issues related to HetNets.

  • 46526.
    Wang, Chunliang
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Computer Assisted Coronary CT Angiography Analysis: Disease-centered Software Development2009Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The substantial advances of coronary CTA have resulted in a boost of use of this new technique in the last several years, which brings a big challenge to radiologists by the increasing number of exams and the large amount of data for each patient. The main goal of this study was to develop a computer tool to facilitate coronary CTA analysis by combining knowledge of medicine and image processing.Firstly, a competing fuzzy connectedness tree algorithm was developed to segment the coronary arteries and extract centerlines for each branch. The new algorithm, which is an extension of the “virtual contrast injection” method, preserves the low density soft tissue around the coronary, which reduces the possibility of introducing false positive stenoses during segmentation.Secondly, this algorithm was implemented in open source software in which multiple visualization techniques were integrated into an intuitive user interface to facilitate user interaction and provide good over¬views of the processing results. Considerable efforts were put on optimizing the computa¬tional speed of the algorithm to meet the clinical requirements.Thirdly, an automatic seeding method, that can automatically remove rib cage and recognize the aortic root, was introduced into the interactive segmentation workflow to further minimize the requirement of user interactivity during post-processing. The automatic procedure is carried out right after the images are received, which saves users time after they open the data. Vessel enhance¬ment and quantitative 2D vessel contour analysis are also included in this new version of the software. In our preliminary experience, visually accurate segmentation results of major branches have been achieved in 74 cases (42 cases reported in paper II and 32 cases in paper III) using our software with limited user interaction. On 128 branches of 32 patients, the average overlap between the centerline created in our software and the manually created reference standard was 96.0%. The average distance between them was 0.38 mm, lower than the mean voxel size. The automatic procedure ran for 3-5 min as a single-thread application in the background. Interactive processing took 3 min in average with the latest version of software. In conclusion, the presented software provides fast and automatic coron¬ary artery segmentation and visualization. The accuracy of the centerline tracking was found to be acceptable when compared to manually created centerlines.

  • 46527.
    Wang, Chunliang
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet.
    Computer-­Assisted  Coronary  CT  Angiography  Analysis: From  Software  Development  to  Clinical  Application2011Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Advances in coronary Computed Tomography Angiography (CTA) have resulted in a boost in the use of this new technique in recent years, creating a challenge for radiologists due to the increasing number of exams and the large amount of data for each patient. The main goal of this study was to develop a computer tool to facilitate coronary CTA analysis by combining knowledge of medicine and image processing, and to evaluate the performance in clinical settings.

    Firstly, a competing fuzzy connectedness tree algorithm was developed to segment the coronary arteries and extract centerlines for each branch. The new algorithm, which is an extension of the “virtual contrast injection” (VC) method, preserves the low-density soft tissue around the artery, and thus reduces the possibility of introducing false positive stenoses during segmentation. Visually reasonable results were obtained in clinical cases.

    Secondly, this algorithm was implemented in open source software in which multiple visualization techniques were integrated into an intuitive user interface to facilitate user interaction and provide good over­views of the processing results. An automatic seeding method was introduced into the interactive segmentation workflow to eliminate the requirement of user initialization during post-processing. In 42 clinical cases, all main arteries and more than 85% of visible branches were identified, and testing the centerline extraction in a reference database gave results in good agreement with the gold standard.

    Thirdly, the diagnostic accuracy of coronary CTA using the segmented 3D data from the VC method was evaluated on 30 clinical coronary CTA datasets and compared with the conventional reading method and a different 3D reading method, region growing (RG), from a commercial software. As a reference method, catheter angiography was used. The percentage of evaluable arteries, accuracy and negative predictive value (NPV) for detecting stenosis were, respectively, 86%, 74% and 93% for the conventional method, 83%, 71% and 92% for VC, and 64%, 56% and 93% for RG. Accuracy was significantly lower for the RG method than for the other two methods (p<0.01), whereas there was no significant difference in accuracy between the VC method and the conventional method (p = 0.22).

    Furthermore, we developed a fast, level set-based algorithm for vessel segmentation, which is 10-20 times faster than the conventional methods without losing segmentation accuracy. It enables quantitative stenosis analysis at interactive speed.

    In conclusion, the presented software provides fast and automatic coron­ary artery segmentation and visualization. The NPV of using only segmented 3D data is as good as using conventional 2D viewing techniques, which suggests a potential of using them as an initial step, with access to 2D reviewing techniques for suspected lesions and cases with heavy calcification. Combining the 3D visualization of segmentation data with the clinical workflow could shorten reading time.

  • 46528.
    Wang, Chunliang
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. KTH Royal Institute Technology, Sweden; Sectra AB, S-58330 Linkoping, Sweden.
    Dahlström, Nils
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Fransson, Sven Göran
    Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper.
    Lundström, Claes
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Smedby, Örjan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. KTH Royal Institute Technology, Sweden.
    Real-Time Interactive 3D Tumor Segmentation Using a Fast Level-Set Algorithm2015Ingår i: Journal of Medical Imaging and Health Informatics, ISSN 2156-7018, E-ISSN 2156-7026, Vol. 5, nr 8, s. 1998-2002Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new level-set based interactive segmentation framework is introduced, where the algorithm learns the intensity distributions of the tumor and surrounding tissue from a line segment drawn by the user from the middle of the lesion towards the border. This information is used to design a likelihood function, which is then incorporated into the level-set framework as an external speed function guiding the segmentation. The endpoint of the input line segment sets a limit to the propagation of 3D region, i.e., when the zero-level-set crosses this point, the propagation is forced to stop. Finally, a fast level set algorithm with coherent propagation is used to solve the level set equation in real time. This allows the user to instantly see the 3D result while adjusting the position of the line segment to tune the parameters implicitly. The "fluctuating" character of the coherent propagation also enables the contour to coherently follow the mouse cursors motion when the user tries to fine-tune the position of the contour on the boundary, where the learned likelihood function may not necessarily change much. Preliminary results suggest that radiologists can easily learn how to use the proposed segmentation tool and perform relatively accurate segmentation with much less time than the conventional slice-by-slice based manual procedure.

  • 46529.
    Wang, Chunliang
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Sectra, Linkoping, Sweden.
    Forsberg, Daniel
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Sectra, Linkoping, Sweden.
    Segmentation of Intervertebral Discs in 3D MRI Data Using Multi-atlas Based Registration2016Ingår i: Computational Methods and Clinical Applications for Spine Imaging, CSI 2015, SPRINGER INT PUBLISHING AG , 2016, Vol. 9402, s. 107-116Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents one of the participating methods to the intervertebral disc segmentation challenge organized in conjunction with the 3rd MICCAI Workshop amp; Challenge on Computational Methods and Clinical Applications for Spine Imaging - MICCAI-CSI2015. The presented method consist of three steps. In the first step, vertebral bodies are detected and labeled using integral channel features and a graphical parts model. The second step consists of image registration, where a set of image volumes with corresponding intervertebral disc atlases are registered to the target volume using the output from the first step as initialization. In the final step, the registered atlases are combined using label fusion to derive the final segmentation. The pipeline was evaluated using a set of 15 + 10 T2-weighted image volumes provided as training and test data respectively for the segmentation challenge. For the training data, a mean disc centroid distance of 0.86 mm and an average DICE score of 91% was achieved, and for the test data the corresponding results were 0.90 mm and 90%.

  • 46530.
    Wang, Chunliang
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Frimmel, Hans
    Institutionen för informationteknologi, Uppsala universitet, Sweden.
    Persson, Anders
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    An interactive software module for visualizing coronary arteries in CT angiography2008Ingår i: International Journal of Computer Assisted Radiology and Surgery, ISSN 1861-6410, Vol. 3, nr 1-2, s. 11-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new software module for coronary artery segmentation and visualization in CT angiography (CTA) datasets is presented, which aims to interactively segment coronary arteries and visualize them in 3D with maximum intensity projection (MIP) and volume rendering (VRT).

    Materials and Methods:  The software was built as a plug-in for the open-source PACS workstation OsiriX. The main segmentation function is based an optimized “virtual contrast injection” algorithm, which uses fuzzy connectedness of the vessel lumen to separate the contrast-filled structures from each other. The software was evaluated in 42 clinical coronary CTA datasets acquired with 64-slice CT using isotropic voxels of 0.3–0.5 mm.

    Results:  The median processing time was 6.4 min, and 100% of main branches (right coronary artery, left circumflex artery and left anterior descending artery) and 86.9% (219/252) of visible minor branches were intact. Visually correct centerlines were obtained automatically in 94.7% (321/339) of the intact branches.

    Conclusion:  The new software is a promising tool for coronary CTA post-processing providing good overviews of the coronary artery with limited user interaction on low-end hardware, and the coronary CTA diagnosis procedure could potentially be more time-efficient than using thin-slab technique.

  • 46531.
    Wang, Chunliang
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Moreno, Rodrigo
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Inter-project Cooperation Using Socket-Based Inter-Process Communication2012Konferensbidrag (Övrigt vetenskapligt)
  • 46532.
    Wang, Chunliang
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Moreno, Rodrigo
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Smedby, Örjan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Vessel Segmentation Using Implicit Model-Guided Level Sets2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes an automatic segmentation method of vasculature that combines level-sets with an implicit 3D model of the vessels. First, a 3D vessel model from a set of initial centerlines is generated. This model is incorporated in the level set propagation to regulate the growth of the vessel contour. After evolving the level set, new centerlines are extracted and the diameter of vessels is re-estimated in order to generate a new vessel model. The propagation and re-modeling steps are repeated until convergence. The organizers of the 3D Cardiovascular Imaging: a MICCAI segmentation challenge report the following results for the 24 testing datasets. The sensitivity and PPV are 0.26, 0.40 for QCA and 0.05 and 0.22 for CTA. As for quantitation, the absolute and RMS dierences for QCA are 29.7% and 34.1% and the weighted kappa for CTA are -0.37. As for lumen segmentation, the dice are 0.68 and 0.69 for healthy and diseased vessel segments respectively. Performance for QCA and lumen segmentation are close to the reported by the organizers for three human observers.

  • 46533.
    Wang, Chunliang
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Smedby, Örjan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    An Automatic Seeding Method For Coronary Artery Segmentation and Skeletonization in CTA2008Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    An automatic seeding method for coronary artery segmentation and skeletonization is presented. The new method includes automatic removal of the rib cage, tracing of the ascending aorta and initial planting of seeds for the coronary arteries. The automatic seeds are then passed on to a “virtual contrast injection” algorithm performing segmentation and skeletonization. In preliminary experiments, most main branches of the coronary tree were segmented and skeletonized without any user interaction.

  • 46534.
    Wang, Chunliang
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Coronary Artery Segmentation and Skeletonization Based on Competing Fuzzy Connectedness Tree2007Ingår i: Medical Image Computing and Computer-Assisted Intervention – MICCAI 2007: 10th International Conference, Brisbane, Australia, October 29 - November 2, 2007, Proceedings, Part I / [ed] Nicholas Ayache, Sébastien Ourselin, Anthony Maeder, Springer Berlin/Heidelberg, 2007, Vol. 4791, s. 311-318Konferensbidrag (Refereegranskat)
    Abstract [en]

    We propose a new segmentation algorithm based on competing fuzzy connectedness theory, which is then used for visualizing coronary arteries in 3D CT angiography (CTA) images. The major difference compared to other fuzzy connectedness algorithms is that an additional data structure, the connectedness tree, is constructed at the same time as the seeds propagate. In preliminary evaluations, accurate result have been achieved with very limited user interaction. In addition to improving computational speed and segmentation results, the fuzzy connectedness tree algorithm also includes automated extraction of the vessel centerlines, which is a promising approach for creating curved plane reformat (CPR) images along arteries’ long axes.

  • 46535.
    Wang, Chunliang
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Smedby, Örjan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Fully automatic brain segmentation using model-guided level set and skeleton based models2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A fully automatic brain segmentation method is presented. First the skull is stripped using a model-based level set on T1-weighted inversion recovery images, then the brain ventricles and basal ganglia are segmented using the same method on T1-weighted images. The central white matter is segmented using a regular level set method but with high curvature regulation. To segment the cortical gray matter, a skeleton-based model is created by extracting the mid-surface of the gray matter from a preliminary segmentation using a threshold-based level set. An implicit model is then built by defining the thickness of the gray matter to be 2.7 mm. This model is incorporated into the level set framework and used to guide a second round more precise segmentation. Preliminary experiments show that the proposed method can provide relatively accurate results compared with the segmentation done by human observers. The processing time is considerably shorter than most conventional automatic brain segmentation methods.

  • 46536.
    Wang, Chunliang
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Integrating automatic and interactive method for coronary artery segmentation: let PACS workstation think ahead2010Ingår i: International Journal of Computer Assisted Radiology and Surgery, ISSN 1861-6410, E-ISSN 1861-6429, Vol. 5, nr 3, s. 275-285Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To provide an efficient method to extract useful information from the increasing amount of coronary CTA.

    Methods: A quantitative coronary CTA analysis tool was built on OsiriX, which integrates both fully automatic and interactive methods for coronary artery extraction. The computational power of an ordinary PC is exploited by running the non-supervised coronary artery segmentation and centerline tracking in the background as soon as the images are received. When the user opens the data, the software provides a real-time interactive analysis environment.

    Results: The average overlap between the centerline created in our software and the reference standard was 96.0%. The average distance between them was 0.38 mm. The automatic procedure runs for 3-5 min as a single-thread application in background. Interactive processing takes 3 min in average.

    Conclusion: In preliminary experiments, the software achieved higher efficiency than the former interactive method, and reasonable accuracy compared to manual vessel extraction.

  • 46537.
    Wang, Chunliang
    et al.
    KTH, Skolan för teknik och hälsa (STH).
    Wang, Q.
    Smedby, Örjan
    KTH, Skolan för teknik och hälsa (STH), Medicinsk teknik, Medicinsk bildbehandling och visualisering.
    Automatic heart and vessel segmentation using random forests and a local phase guided level set method2017Ingår i: Reconstruction, Segmentation, and Analysis Of Medical Images, Springer Verlag , 2017, Vol. 10129, s. 159-164Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this report, a novel automatic heart and vessel segmentation method is proposed. The heart segmentation pipeline consists of three major steps: heart localization using landmark detection, heart isolation using statistical shape model and myocardium segmentation using learning based voxel classification and local phase analysis. In our preliminary test, the proposed method achieved encouraging results.

  • 46538.
    Wang, Cishen
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Matematiska och systemtekniska institutionen.
    Maintenance of a 3D Visualization System2008Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats
    Abstract [en]

    Vizz3D is a powerful 3D visualization system. The current version is neither perfect nor up-to-date. Furthermore, some important features are missing. In order to keep the tool valuable it needs to be maintained. I implemented a new feature allowing to save and load the view port in the graph to control the camera position. I also improved the CPU utilization and the navigation system to solve the limitations in Vizz3D and to improve the overall performance.

  • 46539. Wang, F.
    et al.
    Weng, G.
    Gidlund, Mikael
    ABB Corporate Research.
    Culver, Stephen
    Collaborative Spectrum Sensing in Cognitive Radio System: Performance Analysis of Weighted Gain Combining2011Ingår i: Proceedings, 2011, s. 1-6Konferensbidrag (Refereegranskat)
  • 46540.
    Wang, Gaihua
    et al.
    Hubei Collaborative Innovation Centre for High-efficiency Utilization of Solar Energy, Hubei University of Technology, China / School of Electrical and Electronic Engineering, Hubei University of Technology, China.
    Liu, Yang
    School of Electrical and Electronic Engineering, Hubei University of Technology, China / Faculty of Technology, University of Vaasa, Vaasa, Finland.
    Xiong, Caiquan
    School of Computer Science, Hubei University of Technology, China.
    An Optimization Clustering Algorithm Based on Texture Feature Fusion for Color Image Segmentation2015Ingår i: Algorithms, ISSN 1999-4893, E-ISSN 1999-4893, Vol. 8, nr 2, s. 234-247Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We introduce a multi-feature optimization clustering algorithm for color image segmentation. The local binary pattern, the mean of the min-max difference, and the color components are combined as feature vectors to describe the magnitude change of grey value and the contrastive information of neighbor pixels. In clustering stage, it gets the initial clustering center and avoids getting into local optimization by adding mutation operator of genetic algorithm to particle swarm optimization. Compared with well-known methods, the proposed method has an overall better segmentation performance and can segment image more accurately by evaluating the ratio of misclassification.

  • 46541.
    Wang, Gaihua
    et al.
    School of Electrical and Electronic Engineering, Hubei University of Technology, China.
    Liu, Yang
    School of Electrical and Electronic Engineering, Hubei University of Technology, China / Faculty of Technology, University of Vaasa, Vaasa, Finland.
    Zhao, Tongzhou
    Hubei Province Key Laboratory of Intelligent Robot, Wuhan Institute of Technology, China.
    A quaternion-based switching filter for colour image denoising2014Ingår i: Signal Processing, ISSN 0165-1684, E-ISSN 1872-7557, Vol. 102, s. 216-225Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An improved quaternion switching filter for colour image denoising is presented. It proposes a RGB colour image as a pure quaternion form and measures differences between two colour pixels with the quaternion-based distance. Further, in noise-detection, a two-stage detection method is proposed to determine whether the current pixel is noise or not. The noisy pixels are replaced by the vector median filter (VMF) output and the noise-free ones are unchanged. Finally, we combine the advantages of quaternion-based switching filter and non-local means filter to remove mixture noise. By comparing the performance and computing time processing different images, the proposed method has superior performance which not only provides the best noise suppression results but also yields better image quality compared to other widely used filters.

  • 46542. Wang, H.
    et al.
    Oldfield, M.
    Maestrojuán, I.
    Platt, Duncan
    RISE., Swedish ICT, Acreo.
    Brewster, N.
    Viegas, C.
    Alderman, B.
    Ellison, B. N.
    High sensitivity broadband 360GHz passive receiver for TeraSCREEN2016Ingår i: Proceedings of SPIE - The International Society for Optical Engineering, 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    TeraSCREEN is an EU FP7 Security project aimed at developing a combined active, with frequency channel centered at 360 GHz, and passive, with frequency channels centered at 94, 220 and 360 GHz, imaging system for border controls in airport and commercial ferry ports. The system will include automatic threat detection and classification and has been designed with a strong focus on the ethical, legal and practical aspects of operating in these environments and with the potential threats in mind. Furthermore, both the passive and active systems are based on array receivers with the active system consisting of a 16 element MIMO FMCW radar centered at 360 GHz with a bandwidth of 30 GHz utilizing a custom made direct digital synthesizer. The 16 element passive receiver system at 360 GHz uses commercial Gunn diode oscillators at 90 GHz followed by custom made 90 to 180 GHz frequency doublers supplying the local oscillator for 360 GHz sub-harmonic mixers. This paper describes the development of the passive antenna module, local oscillator chain, frequency mixers and detectors used in the passive receiver array of this system. The complete passive receiver chain is characterized in this paper.

  • 46543.
    Wang, Han
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informationssystem och -teknologi.
    Homomorphic Encryption on the IoT2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Security is always a big problem in IoT (internet of things),when it comes to IoT, there must have cloud computing because many devices in IoT are small embedded devices and they don’t always have enough power to finish some complex calculations. Then, they need to take advantage of a third party system especially cloud at present to finish some operations, but the cloud is not safe enough now, in which some important and private information may be leaked, then people introduce homomorphic encryption which can do calculation on encrypted data. To meet the modern needs for random calculations in which the operation can have random times’ addition and multiplication, researchers are trying to make fully homomorphic encryption practical. So in my thesis, I would choose one fully homomorphic encryption scheme to implement a detailed IoT scenario using some IoT devices such as laptop and raspberry pi. Then I would use performance measurements such as response time calculations to do the performance evaluation such as effectiveness and scalability for this technique. Finally, I find some relationship between different parameters and response time, and also effectiveness, scalability in results and conclusion part.

  • 46544.
    Wang, Hao
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    A new scheme for training ReLU-based multi-layer feedforward neural networks2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Ett nytt schema för träning av rektifierad linjär enhet (ReLU)-baserade och framkopplade neurala nätverk undersöks i denna avhandling. Projektet börjar med en rad-för-rad-uppdateringsstrategi designad för framkopplade neurala nätverk med ett dolt lager (SLFNs). Denna strategi utnyttjar egenskaper i ReLUs och optimerar varje rad i inmatningsviktmatrisen individuellt, enligt en gemensam optimeringsmetod. Därefter föreslås den direkta uppdateringsstrategin (DUS), som har två olika versioner: vektorbaserad metod (VBM) respektive matrisbaserad metod (MBM), för att optimera ingångsviktmatrisen som helhet. Slutli- gen utvidgas DUS till framkopplade neurala nätverk med flera lager (MLFN). Eftersom utvidgningen för generella ReLU-baserade MLFN står inför ett initieringsdilemma presenteras därför en MLFN med en speciell struktur.

    Verifieringsexperiment utförs på sex datamängder för klassificering av flera klasser. Resultaten bekräftar att MBM-algoritmen för SLFN förbättrar prestanda hos neurala nätverk, jämfört med konkurrenten, den regulariserade extrema inlärningsmaskinen. För de flesta använda dataset, fungerar MLFNs med den föreslagna speciella strukturen bättre när man lägger till extra dolda lager.

  • 46545.
    Wang, Hao
    et al.
    National Mobile Communication Research Laboratory, Southeast University, Nanjing, Kina.
    Liu, Nan
    National Mobile Communication Research Laboratory, Southeast University, Nanjing, Kina.
    Ping, Wu
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Signaler och System.
    Pan, ZhiWen
    National Mobile Communication Research Laboratory, Southeast University, Nanjing, Kina.
    You, XiaoHu
    National Mobile Communication Research Laboratory, Southeast University, Nanjing, Kina.
    Three novel opportunistic scheduling algorithms in CoMP-CSB scenario2013Ingår i: Science China-Information Sciences, ISSN 1674-733X, Vol. 56, nr 8, s. 082301-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Coordinated scheduling/beamforming (CSB), which belongs to the coordinated multi-point (CoMP) transmission, has received lots of attention recently due to its great potential to mitigate inter-cell interference (ICI) and to increase the cell-edge throughput, and meanwhile it only requires limited base station cooperation and is easy to implement. However, to the best of our knowledge, there are no effective scheduling algorithms with low complexity and overhead in CoMP-CSB scenario as yet. Thus, in this paper, we propose three novel opportunistic scheduling algorithms in CoMP-CSB scenario. All of them jointly consider the intended channel condition of the scheduled user from its serving cell and the orthogonality between the intended channel and the corresponding interference channels to concurrently scheduled users in nearby cells, thus exploiting multi-user diversity (MUD) and mitigating ICI at the same time. Algorithm 1 cooperatively chooses the most orthogonal user pair within a candidate user set in which all users have a large local channel feedback, while Algorithm 2 concurrently schedules the user pair with the largest ratio between the local channel feedbacks and the aforementioned orthogonality within the same candidate user set. Algorithm 3 performs in the way similar to the proportional fairness scheduling, while making a proper modification for its usage in CoMP-CSB scenario. The performance of the proposed scheduling algorithms are evaluated through simulation. Results show that, they all can significantly enhance the received signal to interference plus noise ratio (SINR) with relatively good fairness guarantee, thus achieving larger throughputs and utilities than several well-known scheduling algorithms. Algorithm 2 even outperforms Algorithm 1 when the aforementioned candidate user set is big enough in size and has a bit more overhead/complexity. Furthermore, Algorithms 3 is the best one among all the three proposed algorithms, but it requires more overhead/complexity than Algorithm 1 and 2. Finally, we give the optimal parameter for all of the three proposed algorithms, which can make a good tradeoff between performance and overhead/complexity.

  • 46546.
    Wang, Hao
    et al.
    Örebro universitet, Handelshögskolan vid Örebro universitet.
    Xie, Yun
    Örebro universitet, Handelshögskolan vid Örebro universitet.
    The use of Online Social Networks in Chinese Collaborative E-learning Education2011Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 46547.
    Wang, Huajun
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Interplay between capacity and energy consumption in C-RAN transport network design2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Current mobile network architecture is facing a big challenge as the traffic demands have been increasing dramatically these years. Explosive mobile data demands are driving a significant growth in energy consumption in mobile networks, as well as the cost and carbon footprints [1]. In 2010, China Mobile Research Institute proposed Cloud Radio Access Network (C-RAN) [2], which has been regarded as one of the most promising architecture to solve the challenge of operators. In C-RAN, the baseband units (BBU) are decoupled from the remote radio units (RRH) and centralized in one or more locations. The feasibility of combination of implementing the very tight radio coordination schemes and sharing baseband processing and cooling system resources proves to be the two main advantages of C-RAN compared to traditional RAN. More importantly, mobile operators can quickly deploy RRHs to expand and make upgrades to their networks. Therefore, the C-RAN has been advocated by both operators and equipment vendors as a means to achieve the significant performance gains required for 5G [3].

    However, one of the biggest barriers has shown up in the deployment of C-RAN as the novel architecture imposes very high capacity requirement on the transport network between the RRHs and BBUs, which is been called fronthaul network. With the implementation of 5G wireless system using advanced multi-antenna transmission (MIMO), the capacity requirement would go further up, as well as the power consumption. One solution has been proposed to solve the problem is to have the baseband functions divided, partially staying with RRHs and other functions would be centralized in BBU pool. Different splitting solutions has been proposed in [4] [5] and [6].

    In this thesis work, we choose four different splitting solutions to build four CRAN architecture models. Under one specific case scenario with the fixed number of LTE base stations, we calculate the transport capacity requirement for fronthaul and adopt three different fronthaul technology. The power consumption is calculated by adding up the power utilized by RRHs, fronthaul network and baseband processing. By comparing the numerical results, split 1 and 2 shows the best results while split 2 is more practical for dense cell area, since split 1 requires large fronthaul capacity. The fronthaul transport technology can be decided according to different density of base stations. TWDM-PON shows better energy performance as fronthaul network when the capacity requirement is high, compared to EPON. However, for larger number of BSs, mm-Wave fronthaul is a better solution in terms of energy efficiency, fiber saving and flexibility.

  • 46548.
    Wang, Hui
    et al.
    Changzhou University, Changzhou, People’s Republic of China.
    Xiao, Shengliang
    Changzhou University, Changzhou, People’s Republic of China.
    Lin, Feiyu
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Informationsteknik.
    Yang, Tianchu
    Changzhou University, Changzhou, People’s Republic of China.
    Yang, Laurence T.
    Huazhong University of Science and Technology, Wuhan, People’s Republic of China.
    Group improved enhanced dynamic frame slotted ALOHA anti-collision algorithm2014Ingår i: Journal of Supercomputing, ISSN 0920-8542, E-ISSN 1573-0484, Vol. 69, nr 3, s. 1235-1253Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the development of information technology and declining in the cost of tags, radio frequency identification (RFID) system has become more and more popular, which has been widely used in a lot of areas, such as logistics tracking, animals identification, medicine, electronic toll collection, inventory, asset management, manufacturing, etc. However, when we use RFID technology to identify the objects, tag collision is one of the important factors to influence the identification efficiency. Currently, Aloha-based algorithm is one of the popular anti-collision algorithms which performs well when the number of tags is small. But it is not very efficient for cases with large number of tags and some areas which tags' number can be estimated, such as warehouse, supermarket, the production lines of smart factory and so on. So in this paper, we proposed a new anti-collision algorithm called group improved enhanced dynamic frame slotted ALOHA (GroupIEDFSA) by estimating the number of unread tags first, comparing the maximum frame size and dividing tags into groups when the number of tags which are activated is large. What is more, compared with enhanced dynamic frame slotted ALOHA (EDFSA) algorithm in the process of identification, GroupIEDFSA algorithm will combine new group based on the unread tags' number. Simulation results show that the efficiency of GroupIEDFSA algorithm system improves by 20 % in time and over 50 % in rounds than EDFSA algorithm in the standard mode, and increases by 1 % in time when we used fast mode.

  • 46549.
    Wang, Huijie
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    Detection of Humans in Video Streams Using Convolutional Neural Networks2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Detta examensarbete undersöker problemet att detektera människor i videströmmar med hjälp av convolutional neural networks (CNNs).

    Under de senaste åren har CNNs ökat i användning, vilket medfört stora förbättringar i noggrannhet och beräkningshastighet. CNN är nu en populär metod i olika datorseende- och bildigenkänningsproblem. I detta projekt fokuserar vi på en specifik subdomän: detektion av människor. Problemet försvåras ytterligare av att vår videodata är inspelad från en huvudmonterad kamera. Detta medför att vårt system behöver hantera ovanliga betraktningsvinklar och rörelseoskärpa.

    Efter att ha tagit hänsyn till beräkningshastighet och detektionskvalitet har vi valt att undersöka två olika CNN-modeller: You Only Look Once (YOLO) och Single Shot MultiBox Detector (SSD). Experimenten har designats för att visa hur robusta metoderna är på att detektera människor i bilder med rörelseoskärpa. Vi har också undersökt hur modifikationer på nätverksstrukturer kan påverka slutresultaten.

    Flera experiment har gjorts i detta projekt. Vi visar att SSD ger bättre resultat än YOLO i många avseenden, vilket beror på att SSD har en bättre designad nätverksstruktur. Genom att utföra fin-anpassning av YOLO och SSD på bildkollektionen i Pascal VOC 2012 kan vi visa att SSD fungerar bra även när vi tränar på färre objektklasser. SSD300 har också god förmåga att lära mönster som påverkats av oskärpa. Vi analyserar även hur valet av position och skalor av de predefinierade sökområdenen påverkar resultaten från SSD300.

    Resultaten visar att SSD-modellen presterar överlägset i realtidsdetektion i videoströmmar. Genom att anpassa strukturerna ytterligare finns potential att uppnå ännu bättre resultat.

  • 46550.
    Wang, Huiting
    KTH, Skolan för datavetenskap och kommunikation (CSC).
    How Will Different Control/Display Ratios Influence Muscle Fatigue and Game Experience in Virtual Reality Games?2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    De senaste årens stora intresse och fokuserade utveckling av tekniken för virtual reality (VR) har resulterat i en motsvarande utveckling av VR-spel. De tidigare använda kontrollerna (såsom mus/tangentbord eller spelkontroll) har visat sig inte vara tillräckliga utan det har utvecklats särskilda handkontroller för just VR för att intuitivt kunna interagera med en virtuell värld. Eftersom en sådan typ av kontroll baseras på handrörelser finns det en stor risk för att användarna att drabbas av muskeltrötthet. Det finns däremot mycket lite aktuell forskning med just detta fokus. I denna studie undersöks hur olika Control/Display (C/D)-förhållanden för VR-handkontroller påverkar muskeltröttheten och spelupplevelsen av VR-spel. Baserat på ett etablerat fiskespel i VR, skapades ett test-scenario som använde Oculus Rift och Oculus Touch (handkontrollen). Därefter genomfördes en användarstudie med 24 deltagare. Deltagarna var uppdelade i tre grupper och varje grupp testade spelet med olika C/D förhållanden (1.0, 0.5 och 0.1). Deltagarens egen uppfattning av trötthet, samt spelupplevelse, samlades in under användartesten. Resultaten visar att tröttheten minskar med minskande C/D-förhållande, samt att spelupplevelsen påverkas av C/D- förhållandet beroende på relationen mellan det exakta förhållandet och 1.0. Utifrån resultaten ges också några förslag för design av VR-spel. 

928929930931932933934 46501 - 46550 av 49806
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf