hh.sePublikasjoner
Endre søk
Begrens søket
1234 1 - 50 of 160
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Agelis, Sacki
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Jacobsson, Sofia
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Alping, Arne
    Ericsson Microwave Systems, Mölndal, Sweden.
    Ligander, Per
    Ericsson Microwave Systems, Mölndal, Sweden.
    Modular interconnection system for optical PCB and backplane communication2002Inngår i: Parallel and Distributed Processing Symposium., Proceedings International, IPDPS 2002, Abstracts and CD-ROM, Los Alamitos, Calif.: IEEE Press, 2002, s. 245-250Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a way of building modular systems with a powerful optical interconnection network. Each module, placed on a Printed Circuit Board (PCB), has a generic optical communication interface with a simple electronic router. Together with optical switching using micro-electromechanical system (MEMS) technology, packet switching over reconfigurable topologies is possible. The interconnection system gives the possibility to integrate electronics with optics without changing existing PCB technology. Great interest from industry is therefore expected and the cost advantages are several: reuse of module designs, module upgrades without changing the PCB, low-cost conventional PCB technology, etc. In the version described in this paper, the interconnection system has 48 bidirectional optical channels for intra-PCB communication on each board. For inter-PCB communication, a backplane with 192 bidirectional optical channels supports communication between twelve PCBs. With 2.5 Gbit/s per optical channel in each direction, the aggregated intra-PCB bit rate is 120 Gbit/s full duplex (on each PCB) while the aggregated inter-PCB bit rate is 480 Gbit/s full duplex. A case study shows the feasibility of the interconnection system in a parallel processing system for radar signal processing.

  • 2.
    Agelis, Sacki
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Optoelectronic router with MOEMS–based reconfigurable shuffle network2004Konferansepaper (Fagfellevurdert)
  • 3.
    Ahmed, Iftikhar
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Farooq, Muhammad
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Switched Multi-hop Priority Queued Networks-Influence of priority levels on Soft Real-time Performance2010Independent thesis Advanced level (degree of Master (One Year)), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    In the last few years, the number of real-time applications has increased. These applications are sensitive and require the methods to utilize existing network capacity efficiently to meet performance requirements and achieve the maximum throughput to overcome delay, jitter and packet loss. In such cases, when the network needs to support highly interactive traffic like packet-switched voice, the network congestion is an issue that can lead to various problems. If the level of congestion is high enough, the users may not be able to complete their calls and have existing calls dropped or may experience a variety of delays that make it difficult to participate smooth conversation.

    In this paper, we investigate the effect of priority levels on soft real-time performance. We use the priority queues to help us manage the congestion, handle the interactive traffic and improve the over all performance of the system. We consider switched multi-hop network with priority queues. All the switches and end-nodes control the real-time traffic with “Earlier Deadline First” scheduling. The performance of the network is characterized in terms of the average delay, the deadline missing ratio and the throughput.

    We will analyze these parameters with both the bursty traffic and evenly distributed traffic. We will analyze different priority levels and will see how the increase in priority level increases the performance of the soft real-time system.

  • 4.
    Ali, Hazem
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Patoary, Mohammad Nazrul Ishlam
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Design and Implementation of an Audio Codec (AMR-WB) using Dataflow Programming Language CAL in the OpenDF Environment2010Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    Over the last three decades, computer architects have been able to achieve an increase in performance for single processors by, e.g., increasing clock speed, introducing cache memories and using instruction level parallelism. However, because of power consumption and heat dissipation constraints, this trend is going to cease. In recent times, hardware engineers have instead moved to new chip architectures with multiple processor cores on a single chip. With multi-core processors, applications can complete more total work than with one core alone. To take advantage of multi-core processors, we have to develop parallel applications that assign tasks to different cores. On each core, pipeline, data and task parallelization can be used to achieve higher performance. Dataflow programming languages are attractive for achieving parallelism because of their high-level, machine-independent, implicitly parallel notation and because of their fine-grain parallelism. These features are essential for obtaining effective, scalable utilization of multi-core processors.

    In this thesis work we have parallelized an existing audio codec - Adaptive Multi-Rate Wide Band (AMR-WB) - written in the C language for single core processor. The target platform is a multi-core AMR11 MP developer board. The final result of the efforts is a working AMR-WB encoder implemented in CAL and running in the OpenDF simulator. The C specification of the AMR-WB encoder was analysed with respect to dataflow and parallelism. The final implementation was developed in the CAL Actor Language, with the goal of exposing available parallelism - different dataflows - as well as removing unwanted data dependencies. Our thesis work discusses mapping techniques and guidelines that we followed and which can be used in any future work regarding mapping C based applications to CAL. We also propose solutions for some specific dependencies that were revealed in the AMR-WB encoder analysis and suggest further investigation of possible modifications to the encoder to enable more efficient implementation on a multi-core target system.

  • 5.
    Alkhawaja, Abdel Rahman
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Sheibani, Hatem
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Security issues with Mobile IP2011Independent thesis Advanced level (degree of Master (One Year)), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    With a rapid growth in wireless technology in recent years, Mobile IP has become very important for consumers and businesses by providing mobility based on IP addresses using several applications, which keep the employees connected with each others with critical information. In mobile IP the node can change its location by maintaining the same IP address and keep connected to the internet, which solves the issue of terminating the communication once it moves.

    Since Mobile IP uses open airwaves as a transmission medium, it is subject to the many security threats that are routed in mobile IP network .Protecting mobile IP from threats and attacks is one of the most challenging task now days. IPSec is a standard security protocol solution for TCP/IP network that provides security through Authentication, Encryption and data integrity services. Mobile IP data traffic can be secured by combining with IP Security (IPSec) protocol.

    This thesis describes Mobile IP operations, security threats, different existing methods for securing mobile IP and then IPSec standard, how it works and why IPSec is the best solution. This thesis also describes how to combine IPSec with a mobile IP to provide a solution called (SecMIP) that protects the mobile device’s communication from any threats. Finally it describes Mobile IPv6, binding update and associated security concern.

  • 6.
    Amerion, Mohsen
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Radio Communication for PIE -  a Tiny Timber Interface2010Independent thesis Advanced level (degree of Master (One Year)), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    Tiny Timber is a very lightweight, real-time kernel for small, event-driven embedded systems.  It implements reactive objects as a way of structuring embedded software. These objects are components that react to incoming events by updating their internal state and issuing an outgoing event. Implementing a control system based on reactive objects enhances the reactivity of the system and it helps to optimize the energy consumption, as the system goes to sleep mode when there is nothing to react to. It is also a programming technique that facilitates the organization of the program.

    In this project, we develop a device driver for radio communication with a Tiny Timber interface. This is an extension to the Platform for Intelligent Embedded (PIE) system which is a robot assembled and used at the IDE department of Halmstad University as a platform for developing new applications as well as for educational purposes in the area of embedded and intelligent systems.  The interface is programmed in C and consists of a collection of device drivers for different components of PIE in the form of reactive objects.

  • 7. Arvidsson, Alexander
    et al.
    Lundberg, Magnus
    Säkerhetshot mot molnet2018Independent thesis Basic level (degree of Bachelor), 10 hpOppgave
    Abstract [sv]

     Att använda sig av molntjänster är idag en växande trend och allt fler företag börjar adoptera molntjänster i sin verksamhet. Trots det upplever många företag att den fortsatta utvecklingen hindras på grund av oro för IT-säkerhetskunskaperna hos leverantörerna. I denna uppsats så ställs frågan “Vilka åtgärder kan tas för att förebygga svagheter och hot mot säkerheten och tillgängligheten av molntjänster?”. Frågan försöker besvaras genom att sammanställa de mest relevanta hoten tillsammans med lösningar på problematiken, genom att utföra en litteraturstudie på ämnet. Uppsatsen inriktar sig främst på leveransmodeller där infrastrukturlösningar erbjuds.  Med den inhämtade kunskapen konstruerades ett formulär med frågor, som sedan skickades ut till olika svenska molntjänstleverantörer. Detta för att försöka skapa en inblick i hur marknaden ser ut när det gäller säkerhetsaspekter, samt vilka åtgärder leverantörerna kan vidta för att hantera säkerhetshot. Uppsatsen har identifierat flera olika hot samt åtgärder för säkerhetsproblem, för tjänster relaterade till infrastruktur lösningar. Uppsatsen bidrar med en bild om vilka åtgärder som en molntjänstleverantör kan ta när det kommer till de mest aktuella säkerhetshot som existerar idag. 

  • 8.
    Azam, A.S.M Faruque
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Johnsson, Markus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Mobile One Time Passwords and RC4 Encryption for Cloud Computing2011Independent thesis Advanced level (degree of Master (One Year)), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    Cloud services have grown very quickly over the past couple of years, giving consumers and companies the chance to put services, resources and infrastructures in the hands of a provider. Therefore removing the need of providing these services themselves. This can for example lead to cost savings, better resource utilization and removing the need of technical expertise for the customers.

    There is big security concerns when using cloud services. Security is very important in cloud computing since people and companies store confidential data in the cloud. It must also be easy to use the services provided, since cloud services have so many users with different technical background. Since the control of services and data needed for the everyday-run of a corporation is being handled by another company, further issues needs to be concerned. The consumer needs to trust the provider, and know that they handle their data in a correct manner, and that resources can be accessed when needed.

    This thesis focuses on authentication and transmission encryption in cloud services. The current solutions used today to login to cloud services have been investigated and concluded that they don't satisfy the needs for cloud services. They are either insecure, complex or costly. It can also be concluded that the best encryption algorithm to use in a cloud environment is RC4, which is secure and at the same time a fast algorithm. Compared to AES, which together with RC4, are the most common encryption methods used over the Internet today, RC4 is the better choice.

    This thesis have resulted in an authentication and registration method that is both secure and easy to use, therefore fulfilling the needs of cloud service authentication. The method have been implemented in a fully working finished solution, that use a regular mobile phone to generate one time passwords that is used to login to cloud services. All of the data transmissions between the client and the server have been configured to use RC4 encryption.

    The conclusions that can be drawn is that the security proposal implemented in this thesis work functions very well, and provide good security together with an ease of use for clients that don't have so much technical knowledge.

  • 9.
    Bade, Hans
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Hedlund, Oscar
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Anti-Forensik: Anti-forensiska metoder på mobila enheter2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Mobiltelefoner har blivit grundläggande för extrahering av digitala artefakter i fo-rensiska utredningar. Androids Linuxbaserade operativsystem medför större möj-ligheter för anti-forensiska metoder, detta gör att kunskap om anti-forensik äressentiell för dagens IT-forensiska utredare. I denna studie belyses effekten avanti-forensik i Androidbaserade mobila enheter samt så upplyses det om dagensanti-forensiska attack metoder mot forensiska verktyg. Genom experiment så vi-sas det hur man kan förhindra ett forensisk verktyg från att extrahera data medanvändning av ett simpelt script.

  • 10.
    Baerveldt, Albert-Jan
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligenta system (IS-lab).
    Arras, Kai Oliver
    EPFL, Lausanne, Switzerland.
    Balkenius, Christian
    Lund University, Lund, Sweden.
    Editorial2003Inngår i: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 44, nr 1, s. 100s. 1-Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 11.
    Balador, Ali
    et al.
    SICS Swedish ICT Västerås AB, Västerås, Sweden. & Polytechnic University of Valencia, Valencia, Spain.
    Böhm, Annette
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Calafate, Carlos T.
    Polytechnic University of Valencia, Valencia, Spain.
    Cano, Juan-Carlos
    Polytechnic University of Valencia, Valencia, Spain.
    A Reliable Token-Based MAC Protocol for V2V Communication in Urban VANET2016Inngår i: 2016 IEEE 27TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATIONS (PIMRC), Piscataway: IEEE , 2016, s. 1586-1591Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Safety applications developed for vehicular environments require every vehicle to periodically broadcast its status information (beacon) to all other vehicles, thereby avoiding the risk of car accidents in the road. Due to the high requirements on timing and reliability posed by traffic safety applications, the current IEEE 802.11p standard, which uses a random access Medium Access Control (MAC) protocol, faces difficulties to support timely and reliable data dissemination in vehicular environments where no acknowledgement or RTS/CTS (Request-to-Send/Clear-to-Send) mechanisms are adopted. In this paper, we propose the Dynamic Token-Based MAC (DTB-MAC) protocol. It implements a token passing approach on top of a random access MAC protocol to prevent channel contention as much as possible, thereby improving the reliability of safety message transmissions. Our proposed protocol selects one of the neighbouring nodes as the next transmitter; this selection accounts for the need to avoid beacon lifetime expiration. Therefore, it automatically offers retransmission opportunities to allow vehicles to successfully transmit their beacons before the next beacon is generated whenever time and bandwidth are available. Based on simulation experiments, we show that the DTB-MAC protocol can achieve better performance than IEEE 802.11p in terms of channel utilization and beacon delivery ratio for urban scenarios.

  • 12.
    Bengtsson, Jerker
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Efficient implementation of stream applications on processor arrays2006Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis concludes work conducted on exploring the usage of parallel and reconfigurable processor architectures in industrial high-performance embedded systems. This kind of systems has by tradition been built using a mix of digital signal processors and custom made hardware. Digital signal processors provide full functional felxibility, but at the cost of lower performance. Custom made hardware can be optimized for specific functions for high performance, but at the cost of inflexibility and high development costs. A desire is to combine flexibility and performance using commercial hardware, without trading too much of performance for flexibility.

    Parallel and reconfigurable architectures provide a flexible computing space constituting processing elements that are coupled through configurable communication structures. Architectures designed with less complex processing elements render a high degree of utilizable parallelism at the cost of having to use a portion of the pocessing elements for control functions. In the thesis it is shown that it is possible to utilize this kind of architecture to achieve high performance efficiency, despite the fact that a large fraction of PEs are required to implement control-oriented portions in a fairly complex algorithm.

    A major problem is that architectures of this kind expose a very complex programming abstraction for compilers and programmers. The approach taken in this work is a domain-specific stream processing model which provides means to express application-specific dataflows and computations in terms of streams. An extensive application study comprising the baseband processing in radio base stations has been used to define sufficient data types, operators and language construct. Furthermore, to support industrial requirements on portability to different architectures, it must be possible to express parallelism and characteristic computations without exposing of hardware details in the source code.

    To be able to prototype and set up experiments with stream processing languages an experimental programming framework has been developed. A first prototype language with specific primitive types, operators and stream constructs has been implemented in order to elaborate with baseband programming. It is demonstrated how these types and operators can be used to express machine-independent bit field and other fine-grained data parallel computations. Furthermore, the language has been designed with constructs for efficient and flexible programming of reconfiguration of distributed function parameters.

  • 13.
    Bengtsson, Jerker
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Intermediate representations for simulation and implementation2010Inngår i: Handbook of Signal processing systems / [ed] S.S Bhattacharyya, E.F. Deprettere, R. Leupers and J. Takala, New York: Springer-Verlag New York, 2010, 1, s. 739-767Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 14.
    Bengtsson, Jerker
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Models and Methods for Development of DSP Applications on Manycore Processors2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Advanced digital signal processing systems require specialized high-performance embedded computer architectures. The term high-performance translates to large amounts of data and computations per time unit. The term embedded further implies requirements on physical size and power efficiency. Thus the requirements are of both functional and non-functional nature. This thesis addresses the development of high-performance digital signal processing systems relying on manycore technology. We propose building two-level hierarchical computer architectures for this domain of applications. Further, we outline a tool flow based on methods and analysis techniques for automated, multi-objective mapping of such applications on distributed memory manycore processors. In particular, the focus is put on how to provide a means for tunable strategies for mapping of task graphs on array structured distributed memory manycores, with respect to given application constraints. We argue for code mapping strategies based on predicted execution performance, which can be used in an auto-tuning feedback loop or to guide manual tuning directed by the programmer. Automated parallelization, optimisation and mapping to a manycore processor benefits from the use of a concurrent programming model as the starting point. Such a model allows the programmer to express different types and granularities of parallelism as well as computation characteristics of importance in the addressed class of applications. The programming model should also abstract away machine dependent hardware details. The analytical study of WCDMA baseband processing in radio base stations, presented in this thesis, suggests dataflow models as a good match to the characteristics of the application and as execution model abstracting computations on a manycore. Construction of portable tools further requires a manycore machine model and an intermediate representation. The models are needed in order to decouple algorithms, used to transform and map application software, from hardware. We propose a manycore machine model that captures common hardware resources, as well as resource dependent performance metrics for parallel computation and communication. Further, we have developed a multifunctional intermediate representation, which can be used as source for code generation and for dynamic execution analysis. Finally, we demonstrate how we can dynamically analyse execution using abstract interpretation on the intermediate representation. It is shown that the performance predictions can be used to accurately rank different mappings by best throughput or shortest end-to-end computation latency.

  • 15.
    Bengtsson, Jerker
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    A domain-specic approach for software development on manycore platforms2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The programming complexity of increasingly parallel processors calls for new tools that assist programmers in utilising the parallel hardware resources. In this paper we present a set of models that we have developed as part of a tool for mapping dataflow graphs onto manycores. One of the models captures the essentials of manycores identified as suitable for signal processing, and which we use as tar- get for our algorithms. As an intermediate representation we introduce timed configuration graphs, which describe the mapping of a model of an application onto a machine model. Moreover, we show how a timed configuration graph by very simple means can be evaluated using an abstract interpretation to obtain performance feedback. This infor- mation can be used by our tool and by the programmer in order to discover improved mappings.

  • 16.
    Bengtsson, Jerker
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    A Domain-specific Approach for Software Development on Manycore Platforms2008Inngår i: SIGARCH Computer Architecture News, ISSN 0163-5964, E-ISSN 1943-5851, Vol. 36, nr 5, s. 2-10Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The programming complexity of increasingly parallel processors calls for new tools that assist programmers in utilising the parallel hardware resources. In this paper we present a set of models that we have developed as part of a tool for mapping dataflow graphs onto manycores. One of the models captures the essentials of manycores identified as suitable for signal processing, and which we use as target for our algorithms. As an intermediate representation we introduce timed configuration graphs, which describe the mapping of a model of an application onto a machine model. Moreover, we show how a timed configuration graph by very simple means can be evaluated using an abstract interpretation to obtain performance feedback. This information can be used by our tool and by the programmer in order to discover improved mappings.

  • 17.
    Bengtsson, Jerker
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Manycore performance analysis using timed configuration graphs2009Inngår i: International Symposium on Systems, Architectures, Modeling, and Simulation, 2009. SAMOS '09 / [ed] Michael Joseph Schulte and Walid Najjar, Piscataway, N.J.: IEEE Press, 2009, s. 108-117Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The programming complexity of increasingly parallel processors calls for new tools to assist programmers in utilising the parallel hardware resources. In this paper we present a set of models that we have developed to form part of a tool which is intended for iteratively tuning the mapping of dataflow graphs onto manycores. One of the models is used for capturing the essentials of manycores that are identified as suitable for signal processing and which we use as target architectures. Another model is the intermediate representation in the form of a timed configuration graph, describing the mapping of a dataflow graph onto a machine model. Moreover, this IR can be used for performance evaluation using abstract interpretation. We demonstrate how the models can be configured and applied in order to map applications on the Raw processor. Furthermore, we report promising results on the accuracy of performance predictions produced by our tool. It is also demonstrated that the tool can be used to rank different mappings with respect to optimisation on throughput and end-to-end latency.

  • 18.
    Bengtsson, Jerker
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Methodologies and tools for development of signal processing software on multicore platforms2008Inngår i: 2008 proceedings of the 41st Annual IEEE/ACM International Symposium on Microarchitecture: MICRO-41, November 8-12, 2008, Lake Como, Italy, Piscataway, N.J.: IEEE Computer Society, 2008, s. 2-Konferansepaper (Fagfellevurdert)
  • 19.
    Bengtsson, Ola
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Baerveldt, Albert-Jan
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Robot localization based on scan-matching - estimating the covariance matrix for the IDC algorithm2003Inngår i: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 44, nr 1, s. 29-40Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have previously presented a new scan-matching algorithm based on the IDC (iterative dual correspondence) algorithm, which showed a good localization performance even in environments with severe changes. The problem of the IDC algorithm is that there is no good way to estimate a covariance matrix of the position estimate, which prohibits an effective fusion with other position estimates of other sensors. This paper presents two new ways to estimate the covariance matrix. The first estimates the covariance matrix from the Hessian matrix of the error function minimized by the scan-matching algorithm. The second one, which is an off-line method, estimates the covariance matrix of a specific scan, from a specific position by simulating and matching scans around the position. Simulation results show that the covariance matrix provided by the off-line method fully corresponds with the real one. Some preliminary tests on real data indicate that the off-line method gives a good quality value of a specific scan position, which is of great value in map building.

  • 20.
    Beremark, Mikael
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Fryland, John
    Högskolan i Halmstad, Akademin för informationsteknologi.
    A Comparison of Intrusion Detection Systems in Home Networks2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The security in home networks is a growing concern, not in the least due to the increase in connected devices with the Internet of Things (IoT). Different types of Intrusion Detection Systems (IDS’s) exists with various system requirements. This thesis will research and compare two of these, Bro and Snort IDS in order to determine their functionality in a low resource environment such as a Raspberry Pi. In order to measure functionality and performance, several experiments have been conducted such as penetration testing and thorough installation and configuration experiments.

  • 21.
    Bergenhem, Carl
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Analysis problems in a spatial reuse ring network with a simple clocking strategy2002Rapport (Annet vitenskapelig)
    Abstract [en]

    This technical report describes the problems associated with analysis of a spatial reuse ring network with a clock strategy also used in previously studied ring networks. The aim for the analysis was to find the worst case deterministic throughput. Some results are achieved and are presented. A worst case bound is found and this can be used for analysing feasibility of message connection sets. However, the bound is pessimistic and does not utilise the bandwidth reuse features of the network. This result does not meet the expectations that where foreseen because the medium access method inherently supports distributed global deadline scheduling. It is concluded that the current clock strategy of the network is the cause of the problems. It is also concluded that the analysis is complicated by the clocking strategy and that by introducing small changes in the network (will be presented in a separate paper), the analysis of the real-time performance will be much simpler. This will lead to a network with less pessimistic assumptions and hence better support for real-time traffic.

  • 22.
    Bergenhem, Carl
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Fibre-ribbon ring network with inherent support for earliest deadline first message scheduling2002Inngår i: Proceedings: International Parallel and Distributed Processing Symposium : April 15-19, 2002, Ft. Lauderdale, Florida, USA, Los Alamitos, Calif.: IEEE , 2002, s. 157-163, artikkel-id 1016235Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a network with earliest deadline first (EDF) scheduling on a per slot basis. The network is called CCR-EDF (Control Channel based Ring network with EDF scheduling). The topology is a pipelined unidirectional fibre-ribbon ring that supports several simultaneous transmissions in non-overlapping segments and with dedicated fibres for clock and arbitration. In each slot the node that has highest priority generates the clock. The clock hand over strategy together with the scheduling feature gives the network the functionality for earliest deadline scheduling of periodic messages belonging to logical real-time connections. Logical realtime connections may be added and removed during runtime, through admission control. Guaranteed realtime communication service is supported to the user. Other services include best effort traffic and special services for parallel and distributed processing such as barrier synchronisation and global reduction.

  • 23.
    Bergenhem, Carl
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Gördén, Bengt
    SUNET/KTH-NOC.
    Åhlander, Anders
    Ericsson Microwave Systems.
    Heterogeneous real-time services in high-performance system area networks - application demands and case study definitions2002Rapport (Annet vitenskapelig)
    Abstract [en]

    To be able to verify the feasibility of high-performance networks, it is essential to evaluate them according to specific application requirements. At the same time, specifications of quite general, or understandable, application requirements are needed for the ability to make repeated analyses on different networks. Especially, heterogeneous real-time requirements must be defined to be able to analyze networks to be used in future applications. In this report, we introduce two application fields where system area networks (SANs) supporting heterogeneous real-time services are highly desirable if not required: radar signal processing and large IP routers. For each application field, a case study with heterogeneous real-time communication requirements is defined. No case studies are presented in this report. Instead, they are defined for later evaluations to determine how suitable networks are for applications with heterogeneous real-time communication requirements.

  • 24.
    Bergenhem, Carl
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Olsson, Jörgen
    VoIvo Technological Development Corporation, Göteborg, Sweden .
    Fibre-ribbon pipeline ring network with distributed global deadline scheduling and deterministic user services2001Inngår i: International Conference on Parallel Processing Workshops, 2001, Los Alamitos: IEEE Computer Society , 2001, s. 311-318, artikkel-id 951967Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper introduces a novel, fair medium access protocol for a pipelined optical ring network. The protocol provides global deadline scheduling of packets. Requests for sending packets are sent by the nodes in the network to a master node. The master uses the deadline information in the requests to determine which packet is most urgent. Arbitration is done in two steps, the collection and distribution phases. The protocol is therefore called two-cycle medium access (TCMA). The network is best suited for LANs and SANs (system area networks) such as a high speed network in a cluster of computers or in an embedded parallel computer. Offered services in this network include best effort messages, guarantee seeking messages, real-time virtual channels, functions used in parallel processing. These are possible without additional higher level protocols. A simulation analysis of the network with the protocol is presented. Further analysis shows minimum slot length and fairness of the protocol.

  • 25.
    Bergman, Lars
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligenta system (IS-lab).
    Using multicoloured halftone screens for offset print quality monitoring2005Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In the newspaper printing industry, offset is the dominating printing method and the use of multicolour printing has increased rapidly in newspapers during the last decade. The offset printing process relies on the assumption that an uniform film of ink of right thickness is transferred onto the printing areas. The quality of reproduction of colour images in offset printing is dependent on a number of parameters in a chain of steps and in the end it is the amount and the distribution of ink deposited on the substrate that create the sensation and thus the perceived colours. We identify three control points in the offset printing process and present methods for assessing the printing process quality in two of these points:

    • Methods for determining if the printing plates carry the correct image

    • Methods for determining the amount of ink deposited onto the newsprint

    A new concept of colour impression is introduced as a measure of the amount of ink deposited on the newsprint. Two factors contribute to values of the colour impression, the halftone dot-size and ink density. Colour impression values are determined on gray-bars using a CCD-camera based system. Colour impression values can also be determined in an area containing an arbitrary combination of cyan magenta and yellow inks. The correct amount of ink is known either from a reference print or from prepress information. Thus, the deviation of the amount of ink can be determined that can be used as control value by a press operator or as input to a control system.

    How a closed loop controller can be designed based on the colour impression values is also shown.

    It is demonstrated that the methods developed can be used for off-line print quality monitoring and ink feed control, or preferably in an online system in a newspaper printing press.

  • 26.
    Bilal, Sardar M.
    et al.
    Department of Computer Science, COMSATS Institute of Information Technology (CIIT), Abbottabad, Pakistan.
    Mustafa, Saad
    Department of Computer Science, COMSATS Institute of Information Technology (CIIT), Abbottabad, Pakistan.
    Saeed, Uzma
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Impact of directional density on GyTAR routing protocol for VANETs in city environments2011Inngår i: Proceedings of the 14th IEEE International Multitopic Conference 2011, INMIC 2011 / [ed] Syed Misbahuddin & Mirza Imran Baig, Piscataway, NJ: IEEE, 2011, s. 296-300Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Vehicular ad hoc networks are highly dynamic and their topology changes frequently due to high speed of vehicles. This result in disconnected networks, therefore, designing a routing protocol for such network is challenging task. The two most important factors which effect routing in vehicular ad hoc networks are Speed and direction. In this work, we propose a novel routing protocol (E-GyTAR) motivated from GyTAR, which was specifically designed for city environments. This paper presents the effect of speed and direction on routing protocol in city environment. City environment consists of junctions and these junctions are selected dynamically on the basis of vehicular speed and directional density. Simulation results show that E-GyTAR incurs less packet loss, and end-to-end delay. © 2011 IEEE.

  • 27.
    Bilstrup, Urban
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Bluetooth and Wireless Multihop Networks in Industrial Communication Systems2008Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    The objective of this thesis is to investigate the use of short-range wireless communication technology in industrial communication systems where there is a need for guaranteed timely delivery of correct information. Methods for achieving such capability are developed in the context of the physical layer, the data link layer and the application layer. Based on the insight that it is impossible to achieve strict determinism in a wireless communication system, a probabilistic definition of hard real-time systems is suggested, and thus a guarantee is given in the form of the probability of fulfilling a certain goal. Since a wireless channel is time variant, it is also necessary to continuously keep track of available resources. Allocation and link management methods for wireless communication systems therefore need to be dynamic and of an online character. An exhaustive resource allocation method with redundancy is first proposed for single message delivery and then extended for the operation of a single Bluetooth piconet. However, many devices in an industrial automation system have limited computational resources, especially if wireless sensors/actuators powered by battery or wireless power are considered. This implies that methods used for resource allocation must be of low computational complexity. The complexity issue becomes evident when large systems are implemented, even if each individual sensor generates small amounts of data. The upstream and downstream flows of data grow rapidly in a hierarchical system with many sub-systems, sensors and actuators. It is empirically shown that the aggregated data flow in a monitoring system requires powerful communication nodes already at low levels in the industrial communication hierarchy. A predictable system requires that representative entities for the available resources are defined. In a communication system with a single broadcast domain, such as a single Bluetooth piconet, the resource space is often limited to the time domain. When a multihop wireless network with multiple broadcast domains is considered, the spatial domain is added as an available resource and, if a multi-channel radio transceiver is used, the frequency is also added as an available resource domain. These three domains represent the physical resource space that is available for a wireless multihop network. These are subject to trade-off in all of the three lowest protocol layers, and one of the most challenging problems in the design of a wireless multihop network is how to achieve efficient sharing of these resources. This problem is addressed by proposing a clustered architecture based on a dual-radio node that enables dynamic use of these resource domains.

  • 28.
    Bilstrup, Urban
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    The next challenge for the communication society: co-operating embedded systems2003Konferansepaper (Fagfellevurdert)
  • 29.
    Björn, Johansson
    Högskolan i Halmstad, Akademin för informationsteknologi.
    End-to-end performance testing of a healthcare alarm system2019Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    Digital services involving large systems with multiple users are ubiquitous in modern society. The systems are often complicated and made up of multiple devices and communication protocols. A fundamental problem in this context is how the behavior of a system changes as the number of users vary. In particular, when do the systems’ resources saturate and how does the system behave when close to saturation. Performance testing is key for addressing this fundamental problem. Performance testing is the scope of this project. Performance tests can be used for inference of, for example, a system's scalability. Furthermore, it can be used to provide general guarantees on the services that can be delivered. Performance testing at the company Phoniro AB is considered. The platform Phoniro Care is the back-end service for the company’s products. The Phoiro 6000 system is one of the products that uses Phoniro Care. The system allows for multiple users and offers alarm services. The primary focus of this project is to determine the behavior of that system during varying levels of simulated load, and furthermore analyze the data extracted from such simulations and tests. The open source software JMeter was used as the tool for performance testing. It was selected from a set of candidate tools that have been evaluated in the literature based on various performance criteria. The results are presented by graphs showing the time evolution of different performance indicators. A conclusion from this work is that the implemented performance testing framework helps to answer questions about the systems’ behavior. Questions that are important for the company’s further development and expansion of the system. Furthermore, the proposed framework establishes a foundation for further inquiries on the subject.

  • 30.
    Blomberg, Jossefin
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Jansson Martén, Felicia
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Klassificering av svenska nyhetsartiklar med hjälp av Support Vector Machines2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Uppsatsen syftar till att minska omfattningen av påverkanskampanjer genom maskininlärningsmodellen Support Vector Machine. Arbetet utgår från en litteraturstudie samt två experiment. Litteraturstudien syftar till att ge en referensram till textklassificering med Support Vector Machines. Det första experimentet innebar träning av en Support Vector Machine för att klassificera svenska nyhetsartiklar utefter pålitlighet. Det andra experimentet innefattade en jämförelse av tränad SVM-modell och andra standardmetoder inom textklassificering. Resultaten från experimenten tyder på att SVM är ett effektivt verktyg för klassificering av svenska nyhetsartiklar men även att det finns fler modeller som är lämpliga för samma uppgift.

  • 31.
    Borg, Richard
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Svensson, Timmy
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Assistansrobot "Slangaren"2011Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    This project is a step towards automatic firefighting. The goal is to decrease the number of personal injuries by replacing the human firefighter with robots or similar technical tools. Especially in very hostile environments due to risk of explosions or building collapse. A robot is easy to replace and can be maneuvered from a safe distance. The idea of the project comes from the company Drones Networking which aims for developing a totally autonomous firefighting system. The result of this project is a prototype of a robot which handles the hose during firefighting.

  • 32.
    Brink, Johan
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Elvland, Erik
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Hansson, Patrik
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Effekterna av GDPR: En jämförelse mellan Personuppgiftslagen och den kommande allmänna dataskyddsförordningen.2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Den 25 maj 2018 kommer Personuppgiftslagen (PuL) att ersättas av EU-förordningen GeneralData Protection Regulation (GDPR). Denna studie har granskat vilka skillnader som finnsmellan GDPR och PuL och även hur företag planerar att hantera de förändringar som GDPRkommer att medföra. Även om GDPR i många avseende är lik PuL kommer den nyaförordningen att påverka allt ifrån den enskilda individen till de största organisationerna.Förordningen kommer innebära mer rättigheter och bättre skydd för den registrerade, vilketbetyder att det kommer ställas högre krav på de företag som behandlar personuppgifter.

    De nya kraven kommer innebära ett omfattande anpassningsarbete inom flera områden. Delskommer det behöva ske administrativa och juridiska förändringar inom verksamheten i form avnya eller uppdaterade avtal. Det kan även komma att krävas tekniska åtgärder för att hanterafrågor som “Rätten att bli glömd”, ”Dataportabilitet”, ”Registerföring” samt det förstärktaskyddet av personuppgifter. Det ställs även krav på att personuppgiftsincidenter måsterapporteras till tillsynsmyndigheten vid upptäckande. Då tillämpningsområdet utökas medfördetta att personuppgifter som lagras ostrukturerat kommer omfattas av lagstiftningen. För attuppnå efterlevnad av förordningen införs krav på att i vissa fall utse ett “Dataskyddsombud” iverksamheten; tillsynsmyndigheten får även befogenhet till att utdöma mycket kraftigasanktioner vid överträdelse av förordningen.

    Beroende på hur en verksamhets personuppgiftshantering ser ut i dagsläget kan dennaanpassning bli mer eller mindre omfattande. Anpassningsarbetets omfattning påverkas av ettantal faktorer exempelvis under vilka förutsättningar som behandlingen sker i nuläget och ivilken omfattning denna sker.

    Inställningen till förordningen bland företag är varierande, de som tar den på allvar har insettatt nya krav kommer att ställas på deras verksamheter och har påbörjat arbetet för att anpassasin verksamhet. Andra anser att de inte berörs i samma utsträckning och är därför inte likaoroliga. På det stora hela kommer förordningen göra att personuppgiftsbehandlingen inomEU/ESS blir säkrare även om resan dit kan kosta.

  • 33.
    Böhm, Annette
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Handover in IEEE 802.11p-based delay-sensitive vehicle-to-infrastructure communication2009Rapport (Annet vitenskapelig)
    Abstract [en]

    Based on communication and cooperation between vehicles and roadside infrastructure, Intelligent Transport Systems (ITS) safety applications offer great potential to avoid traffic accidents or at least reduce their impact. As these applications usually are delay-sensitive, the delay introduced by waiting for access to the wireless communication channel should both be reduced and provided with an upper bound. The proposed IEEE 802.11p standard for short to medium range vehicular communication does not offer these guarantees. In previous work, we presented a MAC (Medium Access Control) enhancement supporting delay-sensitive, safety-critical V2I (Vehicle-to-Infrastructure) applications. Since the proposed enhancement requires a deterministic and fast mechanism to associate a vehicle to a roadside unit (RSU) so that it can be integrated into the centralized polling schedule, we now target the handover and connection setup between a vehicle and an RSU. Although the first connection setup with an RSU still underlies the randomness of the original 802.11p MAC method, we provide a deterministic solution to further enhance the handover procedures by introducing a fast, proactive handover mechanism. We show that the overhead of our solution is limited and still allows our MAC protocol to support safety-critical V2I applications in a densely trafficked highway scenario.

  • 34.
    Böhm, Annette
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Position-based data traffic prioritization in safety-critical, real-time vehicle-to-infrastructure communication2009Inngår i: IEEE International Conference on Communications Workshops, 2009. ICC Workshops 2009 / [ed] IEEE, Piscataway, N.J.: IEEE Press, 2009, s. 205-210Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Future active-safety applications in vehicular networks rely heavily on the support for real-time inter-vehicle communication. The Medium Access Control (MAC) mechanism proposed for the upcoming IEEE 802.11p standard intended for Intelligent Transport Systems (ITS) applications does not offer deterministic real-time support, i.e., the channel access delay is not upper bounded. We therefore propose a vehicle-to-infrastructure (V2I) communication solution extending IEEE 802.11p, by introducing a collision-free MAC phase with an enhanced prioritization mechanism based on vehicle positions and the overall road traffic density. A road side unit using a polling mechanism is then able to provide real-time support such that it can guarantee collision-free channel access within its transmission range. Part of the bandwidth remains unchanged such that best-effort services like ongoing vehicle-to-vehicle (V2V) applications may continue. Our solution guarantees that all communication deadlines of the V2I applications are met, while minimizing the required length of the collision-free phase. This in turn maximizes the amount of bandwidth available for best-effort services and ongoing V2V applications. The position-based prioritization mechanism further improves the throughput of both real-time and best-effort data traffic by focusing the communication resources to the most hazardous areas. The concept is evaluated analytically based on a realistic task set from a V2I merge assistance scenario.

  • 35.
    Böhm, Annette
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Kunert, Kristina
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    A fibre-optic AWG-based real-time network for high-performance embedded computing2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, an architecture and a Medium Access Control (MAC) protocol for a multiwavelength optical communication network, applicable in short range communication systems like System Area Networks (SANs), are proposed. The main focus lies on guaranteed support for hard and soft real-time traffic. The network is based upon a single-hop star topology with an Arrayed Waveguide Grating (AWG) at its center. Traffic scheduling is centralized in one node (residing together with the AWG in a hub), which communicates through a physical control channel. The AWG’s property of spatial wavelength reuse and the combination of fixedtuned and tunable transceivers in the nodes enable simultaneous control and data transmission. A case study with defined real-time communication requirements in the field of Radar Signal Processing (RSP) was carried out and indicates that the proposed system is very suitable for this kind of application.

  • 36.
    Böhm, Annette
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Kunert, Kristina
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Data age based MAC scheme for fast and reliable communication within and between platoons of vehicles2016Inngår i: International Conference on Wireless and Mobile Computing, Networking and Communications, Piscataway: IEEE, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Heavy vehicles driving as platoon with highly reduced inter-vehicle gaps has shown considerable fuel saving potential, but put high timing and reliability requirements on the underlying control data exchange. The recently standardized IEEE 802.11p protocol suite for Vehicular Ad-Hoc Networks (VANETs) and its message types do neither support the demands of a platooning application nor take advantage of its properties. We therefore propose a framework for centralized channel access with retransmission capabilities for safety critical control data exchange based on the data age of earlier received messages, DA-RE (Data Age based REtransmission scheme). A simulation comparison to the 802.11p random access Medium Access Control (MAC) protocol shows that the intelligent assignment of retransmission opportunities considerably improves the reliability of platooning control data. We also propose a power control based scheme for early platoon detection allowing several platoons to temporarily share a channel and show that the safe and reliable operation of their vehicles is not compromised. © 2016 IEEE.

  • 37.
    Cheema, Ansar Zaman
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Saqib, Imran Ullah
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Collaborating ISPs Supporting Various Real-Time Services2010Independent thesis Advanced level (degree of Master (One Year)), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    These days, internet service providers (ISPs) face the challenge about how to increase profitability while hey must ensure a good quality service at the same time and scale up their network. The study involves previous research papers. On the bases of those papers,the comparison is made between different alternatives. The purpose on this study is to find a solution that combines different methods and configurations about how several ISPs could cooperate. Its implementation includes how different ISPs can configure their networks to cooperate on service provision supporting various real-time services.

  • 38. Crossley, Mark
    et al.
    Lindell, Joakim
    Lösenordsmönster: Att förebygga svaga lösenord2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Passwords are used more now than ever before. Their use is based on the ideathat the password is only known to the user and that its secrecy prevents othersfrom accessing potentially valuable or sensitive information. But how secret isa password in today's high tech world? Passwords are generally converted into hashsums and saved in databases. Cracking a password requires that the process is reversed so that the actual password can be derived from the hash sum. This cracking process can beachieved by two methods. An attacker can test all the possible combinations,(brute force cracking) or the attacker can compare the password with a list ofcommonly used passwords (cracking with wordlists). This paper investigates a passwords vulnerability to both brute force crackingand cracking via wordlists. It uses a modern computer's processing speedsto establish the amount of time to crack a certain password via brute forcecracking. It also deploys state of the art techniques to examine a password'scontent. It analyses three databases from dierent online communities to examineany possible correlation between a user's hobby interest and their choiceof password. This paper finds that the majority of passwords won't remain secret for very long. Short passwords which consist of a small alphabet are particularly vulnerable to brute force attacks. However due to the increasing speed of modern computers even passwords which are twelve characters long are still potentially vulnerable. This paper finds that users from a variety of online communities choose common passwords which are likely to be on a wordlist and thus susceptible to cracking via word list attacks.

    This paper provides suggestions on how a user can choose a stronger password.

  • 39.
    Cseplö, Madeleine
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Wilhelmsson, Anna
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Korsbo, Jonna
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Ungdomars medvetenhet om IT-relaterad brottslighet2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Världen vi lever i blir allt mer teknisk för var dag som går, men följer vår kunskap med i denna utveckling? Tyvärr är det inte så, allt för få reflekterar över de risker denna utveckling medför samt hur våra lagar appliceras i denna miljö. På grund av detta kan det vara svårt för både unga och vuxna att veta vad som är tillåtet och ej i den teknologins värld. Numera introduceras barn och ungdomar tidigt för tekniken och debuten för deras självständiga användande av tekniken i allt lägre åldrar och har en stor roll i både utbildningen samt för det sociala umgänget. De sociala medierna har blivit en del av ungdomars vardag och detta har medfört att handlingar som näthat dessvärre har ökat.

     

    Vårt mål med arbetet har varit att skapa en dialog om IT-relaterade brott ungdomar emellan, men även för att upplysa äldre generationer om problemet. Det vi kan konstatera är att det definitivt finns ett behov av att informera ungdomar om ämnet, då mer än hälften av eleverna själva (59.2 %) säger att de vill ha en halvdag i skolan om IT-relaterade brott. Elevernas kunskap om IT-relaterad brottslighet varierade mellan åldrarna, de yngsta kände sig säkrare på vad som på Internet är tillåtet och inte medan enbart 60.5 % av de äldsta eleverna kände sig tillräckligt informerade. Ett annat framtaget resultat är att flera av eleverna har en oroväckande inställning till kränkningar och hat på Internet. De menar att det numera sker så mycket och ofta att de inte längre ser det som ett större problem. Dessutom är det inte många som känner sig oroliga för konsekvenserna om de skulle utföra något olagligt via Internet, endast drygt hälften av de äldre.

     

    Omfattningen av vårt arbete är långt ifrån stor då fallstudien enbart genomfördes på en skola, detta då det var den enda skolan som anmälde sitt intresse till att medverka. Trots detta, är resultaten från vår undersökning mycket intressanta och säger även en hel del om hur medvetenheten antagligen ser ut hos många ungdomar idag. 

  • 40.
    Dawood, Sivan
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Frindt, Catharina
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Bluetooth Low Energy using Trilateration with Anybus Wireless Bolt2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
  • 41.
    Ek, Ida
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Hornebrant, Erik
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Kartläggning av internetbaserad tunn klient2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Då datorer i alla dess former har kommit att bära betydande mängder relevant information för diverse forensiska utredningar så krävs en ingående kunskap gällande hur denna data lämpligast infångas. En typ av klient som nyligen har gjort sitt kommersiella intåg på marknaden är den internetbaserade tunna klienten. Det existerar i dagsläget begränsat med underlag gällande huruvida en sådan klient bär information som är relevant för en IT-forensisk utredning.

    Inom denna uppsats har därför en internetbaserad tunn klient av typen Chromebook varit mål för undersökning. Syftet har varit att kartlägga vilka sårbarheter som existerar, samt om möjligt huruvida dessa kan brukas som underlag vid en forensisk utredning. För detta ändamål har klientens lagrings- samt kommunikationsmönster analyserats. För genomförandet av detta brukades experimentella metodiker i form av penetrationstest samt IT-forensisk undersökning. Det har även kartlagts huruvida programvaror avsedda för operativsystemet Linux kan exekveras på klienten. Ändamålet med detta var att fastställa om klientens volatila minne kan utvinnas med hjälp av verktyg för just Linux.

    Rapportens resultat påvisar att det inom en klient av denna typ finns forensiskt värdefull information att inhämta. Det påvisas även att Chrome OS från en användares perspektiv kan anses som säkert.

  • 42.
    Fan, Xing
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Admission control for switched real-time Ethernet: scheduling analysis versus network calculus2005Inngår i: Proc. of the Swedish National Computer Networking Workshop (SNCNW’05), Halmstad, Sweden, Nov. 23-24, 2005, 2005, s. 4 s.-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Many approaches have been developed to give an estimation of the upper bound of the end-to-end delay or the response-time for real-time application, e.g., the Network Calculus (NC) model and the scheduling analysis. In this paper, we present an approach based on scheduling analysis to support guaranteed real-time services over standard switched Ethernet. Furthermore, we conduct a comparative study between these two admission control schemes, our novel algorithm and an NC-based algorithm. The simulation analysis shows that our feasibility analysis gives up to 50% higher utilization than the popular NC. Another advantage of our solution is that no additional hardware or software modification of the switch and the underlying standard. In our proposal, the traffic differentiation mechanism introduced by the IEEE 802.1D/Q standard and the standard hardware-implemented First Come First Served (FCFS) priority queuing are used in the switch and the source nodes. We have derived a feasibility analysis algorithm to ensure that the real-time requirements can be met. The algorithm also gives, as a sub-result, the needed buffer space in the end nodes and the switch. Moreover, our feasibility analysis supports variable-sized frames and switches with different bit-rates ports.

  • 43.
    Fan, Xing
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Efficient many-to-many communication using an intelligent Ethernet switch2002Rapport (Annet vitenskapelig)
  • 44.
    Fan, Xing
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Guaranteed Real-Time Services in Switched Ethernet Networks with Deadline Scheduling in the End Nodes2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper proposes a switched Ethernet network that supports real-time communication with guaranteed bit rate and end-to-end delay bound. In our proposal, the source nodes use Earliest Deadline First (EDF) scheduling, while the switch uses First Come First Served (FCFS) to control periodic real-time traffic belonging to logical realtime connections. The schedulability condition is drawn and the end-to-end worst-case delay bound is derived for guaranteed real-time traffic, which also gives, as a sub-result, the needed buffer space in the switch. Moreover, different traffic classes are prioritized and put into different output queues in the end nodes and the switch, which minimizes the interference with other traffic when transmitting periodic time-critical messages. The solution requires no additional hardware or software modifications of the switch and the underlying standard. It is based purely on software implementation in the end nodes. Furthermore, the EDF scheduling strategy used in the source nodes allows good resource utilization, while the FCFS scheduling used in the switch limits the switch processing overhead. The paper presents simulation analysis for Fast Ethernet, which verifies our approach of guaranteeing real-time transmission at the same time as achieving high utilization.

  • 45.
    Fan, Xing
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Jonsson, Jan
    Department of Computer Science and Engineering, Chalmers University of Technology, SE-412 96 Gothenburg.
    Guaranteed real-time communication in packet-switched networks with FCFS queuing2009Inngår i: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 53, nr 3, s. 400-417Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a feasibility analysis of periodic hard real-time traffic in packet-switched networks using first come first served (FCFS) queuing but no traffic shapers. Our work constitutes a framework that can be adopted for real-time analysis of switched low-cost networks like Ethernet without modification of the standard network components. Our analysis is based on a flexible network and traffic model, e.g., variable-sized frames, arbitrary deadlines and multiple switches. The correctness of our real-time analysis and the tightness of it for network components in single-switch networks are given by theoretical proofs. The performance of the end-to-end real-time analysis is evaluated by simulations. Moreover, our conceptual and experimental comparison studies between our analysis and the commonly used Network Calculus (NC) shows that our analysis can achieve better performance than NC in many cases.

  • 46.
    Forsberg, Håkan
    et al.
    Department of Computer Engineering, Chalmers University of Technology, Göteborg, Sweden.
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    A scalable and pipelined embedded signal processing system using optical hypercube interconnects2000Inngår i: Proceedings of the 12th IASTED International Conference on Parallel and Distributed Computing and Systems (PDCS 2000), Las Vegas, NV, USA, Nov. 6-9, 2000, Las Vegas: IASTED , 2000, s. 265-272Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a system suitable for embedded signal processing with extreme performance demands. The system consists of several computational modules that work independently and send data simultaneously in order to achieve high throughput. Each computational module is composed of multiple processors connected in a hypercube topology to meet scalability and high bisection bandwidth requirements. Free-space optical interconnects and planar packaging technology make it possible to transform the hypercubes into planes and to take advantage of many optical properties. For instance, optical fan-out reduces hardware cost. This, altogether, makes the system capable of meeting high performance demands in, e.g., massively parallel signal processing. An example system with eleven computational modules and an overall peak performance greater than 2.8 TFLOPS is presented. The effective inter-module bandwidth in this configuration is 1,024 Gbit/s.

  • 47.
    Forsberg, Håkan
    et al.
    Chalmers University of Technology, Göteborg, Sweden.
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Optical interconnect architectures in signal processing systems and terabit communication equipment2001Inngår i: Optik i Sverige 2001: Optics in Sweden 2001: Summeries of contributions to the conference of the Swedish Optical Society held in Stockholm 8 November 2001 / [ed] Ulf Olin and Klaus Biedermann, Stockholm: Swedish Optical Society , 2001Konferansepaper (Fagfellevurdert)
    Abstract [en]

    N/A

  • 48.
    Forsberg, Håkan
    et al.
    Department of Computer Engineering, Chalmers University of Technology, Göteborg, Sweden.
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Åhlander, Anders
    Airborne Radar Division, Ericsson Microwave Systems, Mölndal, Sweden.
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Radar signal processing using pipelined optical hypercube interconnects2001Inngår i: Proceedings of the 15th International Parallel and Distributed Processing Symposium: IPDPS 2001 : abstracts and CD-ROM, Los Alamitos, California: IEEE Computer Society Press , 2001, s. 2043-2052, artikkel-id 925201Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we consider the mapping of two radar algorithms on a new scalable hardware architecture. The architecture consists of several computational modules that work independently and send data simultaneously in order to achieve high throughput. Each computational module is composed of multiple processors connected in a hypercube topology to meet scalability and high bisection bandwidth requirements. Free-space optical interconnects and planar packaging technology make it possible to transform the hypercubes into planes. Optical fan-out reduces the number of optical transmitters and thus the hardware cost. Two example systems are analyzed and mapped onto the architecture. One 64-channel airborne radar system with a sustained computational load of more than 1.6 TFLOPS, and one ground-based 128-channel radar system with extreme inter-processor communication demands.

  • 49.
    Garcia, Alejandro
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Johansson, Lisbeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Weckstén, Mattias
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Guaranteed periodic real-time communication over wormhole switched networks2000Inngår i: Parallel and distributed computing systems: proceedings of the ISCA 13th international conference, Las Vegas, Nevada, USA, August 8 - 10, 2000 / [ed] Ghulam Chaudhry; Edwin Sha, Raleigh, NC: INTERNATIONAL SOCIETY COMPUTERS & THEIR APPLICATIONS (ISCA) , 2000, s. 632-639Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we investigate how to efficiently implement TDMA (Time Division Multiple Access) on a wormhole switched network using a pure software solution in the end nodes. Transmission is conflict free on the time-slot level and hence deadlock free. On the sub- slot level, however, conflicts are possible when using early sending, a method we propose in order to reduce latency while still not hazarding the TDMA schedule. We propose a complete system to offer services for dynamic establishment of guaranteed periodic real-time virtual channels. Two different clock synchronization approaches for integration into the TDMA system are discussed. Implementation and experimental studies have been done on a cluster of PCs connected by a Myrinet network. Also, a case study with a radar signal processing application is presented to show the usability. A best-case reduction of the latency of up to 37 percent for 640 Byte messages by using early sending in Myrinet is shown in the case study. Source routed wormhole switching networks are assumed in the work but the results are applicable on some other categories of switched networks too.

  • 50.
    Genestig, Peter
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Gustafsson, Joel
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Analys av DDoS-attacker för identifiering och prevention2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Beroendet av internet har ökat markant över de senaste tjugo åren, detta har medförtatt tjänster som tidigare tillhandahölls lokalt i fysisk form har sakta fasats ut. Samhälletsförtroende för internet och dess struktur medför vissa svagheter, som öppnar upp förattacker vilka kan överbelasta plattformar och göra företagets tjänster otillgängliga.Syftet med arbetet är att identifiera DDoS-attacker från pcap-filer och undersöka hurDRDoS-attacker skalar. Arbetet tar även upp frågeställningar om likheter och skillnadermellan attackerna som används samt huruvida de skiljer sig från legitim trafik och hurdetta kan vara ett problem när skydd eller liknande implementeras.För att besvara frågeställningarna har vi valt att göra tre experiment samt analys. De treexperiment görs i en fysisk labbmiljö där attackerna kan ske på ett kontrollerat miljö,där pcap-filer kan samlas in för analys.I arbetet påvisades att en reflektionsattack som utnyttjade DNS kunde uppnå enskalning med en faktor på 80 gånger. Det har även påvisats vilka likheter som finnsmellan de fem attacker som granskades.

1234 1 - 50 of 160
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf