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  • 1.
    Agelis, Sacki
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Jacobsson, Sofia
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Halmstad University, School of Information Technology, 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 communication2002In: Parallel and Distributed Processing Symposium., Proceedings International, IPDPS 2002, Abstracts and CD-ROM, Los Alamitos, Calif.: IEEE Press, 2002, p. 245-250Conference paper (Refereed)
    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.

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  • 2.
    Agelis, Sacki
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Optoelectronic router with MOEMS–based reconfigurable shuffle network2004Conference paper (Refereed)
  • 3.
    Ahmed, Iftikhar
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Farooq, Muhammad
    Halmstad University, School of Information Science, Computer and Electrical Engineering (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 credits / 22,5 HE creditsStudent thesis
    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.

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  • 4.
    Alfakir, Omar
    et al.
    Halmstad University, School of Information Technology.
    Larsson, Viktor
    Halmstad University, School of Information Technology.
    Ambulance CPR Application: Using cross-platform mobile development2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

     The overall purpose of this project is to develop a cross-platform CPR (cardiopulmonary resuscitation) application mainly for iOS and Android devices. This application aims to guide healthcare workers in the different processes and expected medication during cardiac arrest, which can often be a fast-paced and stressful scenario. The application will need to provide time-based and previous action-based recommendations for following medication and steps. Each step taken as well as at what time it was performed will also need to be documented automatically through the usage of the application.  This application is implemented using the framework React Native. Facebook developed React Native in 2015 targeting mobile application development. The base structure of React Native is based on React, a JavaScript library released in 2013 used to build web interfaces. React Native allows creation of mobile applications that can run on iOS and Android devices with a single codebase.  This project resulted in a mobile application capable of running on both iOS and Android platforms. The application has enough functionality to be used in a simulation for the CPR procedure during a cardiac arrest rescue scenario.

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  • 5.
    Ali, Hani
    et al.
    Halmstad University, School of Information Technology.
    Sunnergren, Pontus
    Halmstad University, School of Information Technology.
    Scenanalys - Övervakning och modellering2021Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Autonomous vehicles can decrease traffic congestion and reduce the amount of traffic related accidents. As there will be millions of autonomous vehicles in the future, a better understanding of the environment will be required. This project aims to create an external automated traffic system that can detect and track 3D objects within a complex traffic situation to later send these objects’ behavior for a larger-scale project that manages to 3D model the traffic situation. The project utilizes Tensorflow framework and YOLOv3 algorithm. The project also utilizes a camera to record traffic situations and a Linux operated computer. Using methods commonly used to create an automated traffic management system was evaluated. The final results show that the system is relatively unstable and can sometimes fail to recognize certain objects. If more images are used for the training process, a more robust and much more reliable system could be developed using a similar methodology. 

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  • 6.
    Ali, Hazem
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Patoary, Mohammad Nazrul Ishlam
    Halmstad University, School of Information Science, Computer and Electrical Engineering (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 credits / 45 HE creditsStudent thesis
    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.

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  • 7.
    Alkhawaja, Abdel Rahman
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Sheibani, Hatem
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Security issues with Mobile IP2011Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    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.

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  • 8.
    Alsaudi, Omar
    et al.
    Halmstad University, School of Information Technology.
    Tallozy, Yaman Mahmoud
    Halmstad University, School of Information Technology.
    Developing the next generation of drones for water monitoring: Implementation of the User Interface (UI) of an internal website2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is about implementing Graphical User Interface for the CatFish website. The CatFish project is iterative research on water pollution where samples from water bodies aremonitored and collected using three different vehicles. The authors of this report, the frontend team, have created a website that aims to represent collected data from the vehicles in the form of diagrams and charts. It also shows live video streaming and gives the CatFish team the ability to control the vehicles remotely. Our results have shown that the website is functional, user-friendly, and ready to be hosted and used.

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  • 9.
    Al-Saydali, Josef
    et al.
    Halmstad University, School of Information Technology.
    Al-Saydali, Mahdi
    Halmstad University, School of Information Technology.
    Anti-forensic Techniques: Feasibility and Efficiency against Forensic Tools2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The anti-forensics process using different methods to hide information or alter it which can lead theinvestigation to the wrong direction. The rising of new skills and experience levels can put the wholeinvestigation in jeopardy especially in the aspect of financial and time loss. Anti-forensics toolsleveraging the cryptographic techniques, data deletion and more novel methods to counter theforensics tools. In this thesis we will examine the techniques that are used by criminals to break downthe cybercrime investigation and all related digital forensics. The focus in this theses will be theeffectiveness of the anti-forensics techniques in hiding traces from the forensics tools.

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  • 10.
    Amerion, Mohsen
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Radio Communication for PIE -  a Tiny Timber Interface2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    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.

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  • 11.
    Andreasson, Samuel
    et al.
    Halmstad University, School of Information Technology.
    Palmér, Jesper
    Halmstad University, School of Information Technology.
    OPC UA Field eXchange Prototyping: Enabling decentralized communication using Publish/Subscribe2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Open Platform Communication Unified Architecture, or OPC UA, is a world-leading communication protocol specializing in unifying and automating production systems communication. In 2018 the OPC Foundation, an industrial consortium, started the OPC UA Field eXchange initiative to develop the current protocol to extend the reach of the communication down to field level devices like sensors and actuators. This paper explores whether OPC UA FX software can be implemented and integrated with HMS Networks’ product AnyBus CompactCom M40. 

    The problem formulation stems from the future need for factory communication. For factories to compete, they need to adapt and keep up with the technological progression. OPC UA FX is based on decentralized communication where devices transmit data to each other by distributing the load over the entire system.  

    The purpose of this report is to, based on the Open62541 implementation, develop software that extends OPC UA with PubSub functionality and methods that enable two or more instances to run as an FX application, meaning that the program publishes and subscribes data simultaneously. Once the software is developed, we integrate it on an AnyBus CompactCom 40 module. This will work as a communication prototype that proves that it is possible to extend OPC UA with FX into HMS Networks’ products. 

    Open62541 is used to gather libraries and methods needed for OPC UA development. The software is developed using C in Visual Studios and integrated into the hardware using Eclipse. 

    The result in the form of software was a connection-oriented data exchange, based on the OPC UA information model, where two or more instances can publish and subscribe to information simultaneously. HMS Networks can use the result on their way to implementing OPC UA FX in their products. 

    In conclusion, the Open62541 implementation is beneficial when developing the OPC UA protocol. The software is complete, but it could not be fully integrated into the CompactCom module. The achieved application is still useful for the development of HMS Network’s products that might use the protocol.

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  • 12. Arvidsson, Alexander
    et al.
    Lundberg, Magnus
    Säkerhetshot mot molnet2018Independent thesis Basic level (degree of Bachelor), 10 HE creditsStudent thesis
    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. 

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  • 13.
    Azam, A.S.M Faruque
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Johnsson, Markus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Mobile One Time Passwords and RC4 Encryption for Cloud Computing2011Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    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.

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  • 14.
    Bade, Hans
    et al.
    Halmstad University, School of Information Technology.
    Hedlund, Oscar
    Halmstad University, School of Information Technology.
    Anti-Forensik: Anti-forensiska metoder på mobila enheter2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Mobile phones have become essential for the extraction of digital artifacts in foren-sic investigations. Android’s Linux-based operating systems bring greater potentialfor anti-forensic methods, which means that knowledge of anti-forensics is essen-tial to today’s IT forensic investigators. In this study, the effect of anti-forensicson Android-based mobile devices is highlighted, as well as revealing today’s anti-forensic attack methods against forensic tools. By experiment, it is shown how toprevent a forensic tool from extracting data by using a simple script.

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  • 15.
    Baerveldt, Albert-Jan
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Arras, Kai Oliver
    EPFL, Lausanne, Switzerland.
    Balkenius, Christian
    Lund University, Lund, Sweden.
    Editorial2003In: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 44, no 1, p. 100p. 1-Article in journal (Other (popular science, discussion, etc.))
  • 16.
    Balador, Ali
    et al.
    SICS Swedish ICT Västerås AB, Västerås, Sweden. & Polytechnic University of Valencia, Valencia, Spain.
    Böhm, Annette
    Halmstad University, School of Information Technology, 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 VANET2016In: 2016 IEEE 27TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATIONS (PIMRC), Piscataway: IEEE , 2016, p. 1586-1591Conference paper (Refereed)
    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.

  • 17.
    Bengtsson, Jerker
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Efficient implementation of stream applications on processor arrays2006Licentiate thesis, comprehensive summary (Other academic)
    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.

  • 18.
    Bengtsson, Jerker
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Intermediate representations for simulation and implementation2010In: 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, p. 739-767Chapter in book (Other academic)
  • 19.
    Bengtsson, Jerker
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Models and Methods for Development of DSP Applications on Manycore Processors2009Doctoral thesis, comprehensive summary (Other academic)
    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.

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  • 20.
    Bengtsson, Jerker
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Svensson, Bertil
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    A domain-specic approach for software development on manycore platforms2008Conference paper (Refereed)
    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.

  • 21.
    Bengtsson, Jerker
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Svensson, Bertil
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    A Domain-specific Approach for Software Development on Manycore Platforms2008In: SIGARCH Computer Architecture News, ISSN 0163-5964, E-ISSN 1943-5851, Vol. 36, no 5, p. 2-10Article in journal (Refereed)
    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.

  • 22.
    Bengtsson, Jerker
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Svensson, Bertil
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Manycore performance analysis using timed configuration graphs2009In: International Symposium on Systems, Architectures, Modeling, and Simulation, 2009. SAMOS '09 / [ed] Michael Joseph Schulte and Walid Najjar, Piscataway, N.J.: IEEE Press, 2009, p. 108-117Conference paper (Refereed)
    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.

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  • 23.
    Bengtsson, Jerker
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Svensson, Bertil
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Methodologies and tools for development of signal processing software on multicore platforms2008In: 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, p. 2-Conference paper (Refereed)
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  • 24.
    Bengtsson, Lars
    et al.
    Halmstad University, School of Information Technology.
    Linde, Arne
    Halmstad University, School of Information Technology.
    Svensson, Bertil
    Halmstad University, School of Information Technology.
    Taveniku, Mikael
    Halmstad University, School of Information Technology.
    Åhlander, Anders
    Halmstad University, School of Information Technology.
    REMAP massively parallel computer platform for neural computations1997In: Proceedings of the Third International Conference on Microelectronics for Neural Networks (MicroNeuro’93), 1997, no 1342, p. 47-62Conference paper (Refereed)
    Abstract [en]

    The REMAP project addresses questions related to the use of massively parallel, distributed computing in embedded systems. Of specific interest is the execution of artificial neural network algorithms on multiple, cooperating processor arrays. This paper concentrates on the recently finished, and currently used, processor array prototype, REMAP-β, of SIMD (Single Instruction stream, Multiple Data streams) type. The architecture and implementation of the computer is described, both its overall structure and its constituent parts. Following this comes a discussion of its use as an architecture laboratory, which stems from the fact that it is implemented using FPGA (Field Programmable Gate Array) circuits. As an architecture laboratory the prototype can be used to implement and evaluate, e.g., various Processing Element (PE) designs. A couple of examples of PE architectures, including one with floating-point support, are given. The mapping of important neural network algorithms on processor arrays of this kind is shown, and possible tuning of the architecture to meet specific processing demands is discussed. Performance figures are given as well as implications for future VLSI implementations of the array.

  • 25.
    Bengtsson, Lars
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Nilsson, Kenneth
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Svensson, Bertil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS). Department of Computer Engineering, Chalmers University of Technology, Göteborg, Sweden.
    A processor array module for distributed, massively parallel, embedded computing1993In: Microprocessing and Microprogramming, ISSN 0165-6074, Vol. 38, no 1-5, p. 529-537Article in journal (Refereed)
    Abstract [en]

    With the increased degree of miniaturization resulting from the use of modem VLSI technology and the high communication bandwidth available through optical connections, it is now possible to build massively parallel computers based on distributed modules which can be embedded in advanced industrial products. Examples of such future possibilities are ''action-oriented systems'', in which a network of highly parallel modules perform a multitude of tasks related to perception, cognition, and action. The paper discusses questions of architecture on the level of modules and inter-module communication and gives concrete architectural solutions which meet the demands of typical, advanced industrial real-time applications. The interface between the processors arrays and the all-optical communication network is described in some detail. Implementation issues specifically related to the demand for miniaturization are discussed.

  • 26.
    Bengtsson, Ola
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Baerveldt, Albert-Jan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Robot localization based on scan-matching - estimating the covariance matrix for the IDC algorithm2003In: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 44, no 1, p. 29-40Article in journal (Refereed)
    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.

  • 27.
    Beremark, Mikael
    et al.
    Halmstad University, School of Information Technology.
    Fryland, John
    Halmstad University, School of Information Technology.
    A Comparison of Intrusion Detection Systems in Home Networks2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    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.

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  • 28.
    Bergenhem, Carl
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Protocols with Heterogeneous Real-Time Services for High-Performance Embedded Networks2002Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Network protocols for applications that demand high performance and heterogeneous real-time services are presented. These protocols control the medium access to the network and offer additional features to the user, both different user services for traffic and services for parallel and distributed real-time processing. The network architecture assumed is a unidirectional pipelined optical ring.

    Radar Signal Processing (RSP) is a typical application area. Such a system contains many computation nodes that are interconnected in order to co-operate and thereby achieve higher performance. The computing performance of the whole system is greatly affected by the choice of network. Computing nodes in a parallel computer for RSP should be tightly coupled, i.e., communications cost (e.g. latency) between nodes should be small, so that the whole system can be perceived as a single unit. This is possible if a suitable network with an efficient protocol is used.

    There is an industrial need for new high-performance networks with support for the, often heterogeneous, real-time requirements found in (often embedded) applications such as RSP and other areas such as multimedia. The traffic this kind of network can be classified according to its requirements. The proposed protocols partition the traffic into three classes with distinctly different qualities. These classes are traffic with hard real-time demands, such as mission critical commands, traffic with soft real-time demands, such as process data (a deadline miss here only leads to decreased performance) and, finally, traffic with no real-time constraints at all. The contributions of the present thesis are protocols that integrate heterogeneous real-time services for the three traffic classes.

    The performance of the proposed protocols is evaluated through simulations and analysis. It is shown that the protocol is an efficient choice for RSP systems. A brief survey of related technologies is included in the thesis. These are studied from the perspectives of application, architecture and user service.

  • 29.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Analysis problems in a spatial reuse ring network with a simple clocking strategy2002Report (Other academic)
    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.

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  • 30.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Fibre-ribbon ring network with inherent support for earliest deadline first message scheduling2002In: Proceedings: International Parallel and Distributed Processing Symposium : April 15-19, 2002, Ft. Lauderdale, Florida, USA, Los Alamitos, Calif.: IEEE , 2002, p. 157-163, article id 1016235Conference paper (Refereed)
    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.

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  • 31.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (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 definitions2002Report (Other academic)
    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.

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  • 32.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Olsson, Jörgen
    VoIvo Technological Development Corporation, Göteborg, Sweden .
    Fibre-ribbon pipeline ring network with distributed global deadline scheduling and deterministic user services2001In: International Conference on Parallel Processing Workshops, 2001, Los Alamitos: IEEE Computer Society , 2001, p. 311-318, article id 951967Conference paper (Refereed)
    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.

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  • 33.
    Bergman, Lars
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Using multicoloured halftone screens for offset print quality monitoring2005Licentiate thesis, comprehensive summary (Other academic)
    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.

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  • 34.
    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
    Halmstad University, School of Information Technology.
    Impact of directional density on GyTAR routing protocol for VANETs in city environments2011In: Proceedings of the 14th IEEE International Multitopic Conference 2011, INMIC 2011 / [ed] Syed Misbahuddin & Mirza Imran Baig, Piscataway, NJ: IEEE, 2011, p. 296-300Conference paper (Refereed)
    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.

  • 35.
    Bilstrup, Urban
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Bluetooth and Wireless Multihop Networks in Industrial Communication Systems2008Doctoral thesis, monograph (Other academic)
    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.

  • 36.
    Bilstrup, Urban
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES).
    Svensson, Bertil
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES).
    The next challenge for the communication society: co-operating embedded systems2003Conference paper (Refereed)
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  • 37.
    Bilstrup, Urban
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Wiberg, Per-Arne
    Free2move AB.
    An architecture comparison between a wireless sensor network and an active RFID system2004In: The 29th Annual IEEE International Conference on Local Computer Networks, 2004, IEEE, 2004, p. 583-584Conference paper (Refereed)
    Abstract [en]

    In This work a new hardware platform for active RFID and wireless sensor network is presented. Furthermore a comparison of these two architectures is performed, i.e., the singlehop and the multihop architecture. The comparison reveals important issues regarding the utilization and energy consumption for the singlehop as well as for the multihop architecture.

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  • 38.
    Bilstrup, Urban
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Wiberg, Per-Arne
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    An Implementation of a 3-tier Hierarchical Wireless Sensor Network2006In: 2006 IEEE International Conference on Industrial Informatics, Piscataway, N.J.: IEEE Press, 2006, p. 138-143Conference paper (Refereed)
    Abstract [en]

    In this paper an implementation of a wireless sensor network is described. The aim with the implementation is to investigate if present design patterns are applicable on wireless sensor networks. A 3-tier model is adopted as a possible candidate for the software as well as for the network architecture. The implemented wireless sensor network consists of a heterogeneous set of hardware devices such as sensors, sensor hubs, beepers, PDAs and connectors. Most of the hardware components are COTS and most of the software is GNU licensed. All these form a 3-tier hierarchical network architecture.

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  • 39.
    Björn, Johansson
    Halmstad University, School of Information Technology.
    End-to-end performance testing of a healthcare alarm system2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    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.

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  • 40.
    Blomberg, Jossefin
    et al.
    Halmstad University, School of Information Technology.
    Jansson Martén, Felicia
    Halmstad University, School of Information Technology.
    Klassificering av svenska nyhetsartiklar med hjälp av Support Vector Machines2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this paper is to reduce the extent of impact campaigns through use of the machine learning algorithm Support Vector Machine. The process involved a literature study and two experiments. The aim of the literature study was to give a frame of reference to text classification with Support Vector Machines. The first experiment involved training a SVM to be able to classify news articles written in swedish based on the reliability of the article. The second experiment involved a comparison between the trained SVM-model and other standard methods in the field. The results from the experiment indicates that SVM is a effective tool for classification of news articles written in Swedish, but also that other standard methods are suitable for the same task.

  • 41.
    Borg, Richard
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Svensson, Timmy
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Assistansrobot "Slangaren"2011Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    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.

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    Examensrapport Assistansrobot
  • 42.
    Brandhild, Kevin
    Halmstad University.
    Azure Policy Definition Builder2021Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Cloud technologies are spearheading today’s innovation and automation efforts. With the use of Azure Policy it is possible to govern Azure resources and services through customized Azure policy definitions. This project aims to simplify the creation process for the Azure policy definition by creating a web application that removes the need to construct the JSON structure. Instead of code-based, it uses click&add to create the code blocks. The web application was created through the library React and with the use of Typescript as the main programming language. The result is a web application that removes the need to construct the JSON structure and instead produces this JSON structure for the user. The project concludes that the result web application did not fully achieve simplification through click&add. However, it creates a good basis for further development of policy simplification. In its current form, the app can be viewed as an alternative method for creating an Azure policy definition.

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  • 43.
    Brink, Johan
    et al.
    Halmstad University, School of Information Technology.
    Elvland, Erik
    Halmstad University, School of Information Technology.
    Hansson, Patrik
    Halmstad University, School of Information Technology.
    Effekterna av GDPR: En jämförelse mellan Personuppgiftslagen och den kommande allmänna dataskyddsförordningen.2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On the 25th of May 2018 the Swedish Personal Data Act (Personuppgiftslagen, PuL) will be replaced by the EU-regulation General Data Protection Regulation (GDPR). The aim of this study was to determine the big differences between PuL and the GDPR while also looking at how organisations plan to handle the changes that the new regulation will bring. PuL and GDPRare in many ways similar but there are some major changes that will affect every person and every organisation within the EU/EES. The regulation will mean better and morecomprehensive rights for the individual, which in turn will result in higher requirements beingput on the companies who process personal data.

    The new requirements will result in extensive work within several areas to adapt to the new regulation. The legal and administrative sections will need to review their current contracts & agreements and update them if necessary. There may also need to implement technical solutionsto manage the requirements concerning “the right to be forgotten”, “data portability”, “recordkeeping” and the improved protection of personal data. According to the regulationorganisations are required to notify the supervisory authority of any data breach concerningpersonal data. The change in material scope will result in personal data stored in an unstructuredway being covered by the GDPR. To make companies follow the new legislation thesupervisory authority gains the power to levy significant fines if organisations violate the newregulation; in addition some organisations will need to appoint a “Data protection officer”that’ll monitor the processing of personal data.

    There are several factors that will determine the amount of work required to reach compliance;for example the size of the corporation and the extent of their current processing of personaldata.

    The attitude to the new regulation vary, those that take the regulation seriously have realisedthat there will be new demands put on their business, and have already started to adapt theirbusiness to reach compliance with the regulation. There are others that deem that they will notbe affected to the same extent and are therefore not as worried. In the great scope of things, theregulation will make the processing of personal data more secure within the EU/EES eventhough the peregrination to reach compliance may turn out to be a costly one.

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  • 44.
    Buono, Vincenzo
    et al.
    Halmstad University, School of Information Technology.
    Åkesson, Isak
    Halmstad University, School of Information Technology.
    Towards gradient faithfulness and beyond2023Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The riveting interplay of industrialization, informalization, and exponential technological growth of recent years has shifted the attention from classical machine learning techniques to more sophisticated deep learning approaches; yet its intrinsic black-box nature has been impeding its widespread adoption in transparency-critical operations. In this rapidly evolving landscape, where the symbiotic relationship between research and practical applications has never been more interwoven, the contribution of this paper is twofold: advancing gradient faithfulness of CAM methods and exploring new frontiers beyond it.

    In the first part, we theorize three novel gradient-based CAM formulations, aimed at replacing and superseding traditional Grad-CAM-based methods by tackling and addressing the intricately and persistent vanishing and saturating gradient problems. As a consequence, our work introduces novel enhancements to Grad-CAM that reshape the conventional gradient computation by incorporating a customized and adapted technique inspired by the well-established and provably Expected Gradients’ difference-from-reference approach. Our proposed techniques– Expected Grad-CAM, Expected Grad-CAM++and Guided Expected Grad-CAM– as they operate directly on the gradient computation, rather than the recombination of the weighing factors, are designed as a direct and seamless replacement for Grad-CAM and any posterior work built upon it.

    In the second part, we build on our prior proposition and devise a novel CAM method that produces both high-resolution and class-discriminative explanation without fusing other methods, while addressing the issues of both gradient and CAM methods altogether. Our last and most advanced proposition, Hyper Expected Grad-CAM, challenges the current state and formulation of visual explanation and faithfulness and produces a new type of hybrid saliencies that satisfy the notion of natural encoding and perceived resolution. By rethinking faithfulness and resolution is possible to generate saliencies which are more detailed, localized, and less noisy, but most importantly that are composed of only concepts that are encoded by the layerwise models’ understanding.

    Both contributions have been quantitatively and qualitatively compared and assessed in a 5 to 10 times larger evaluation study on the ILSVRC2012 dataset against nine of the most recent and performing CAM techniques across six metrics. Expected Grad-CAM outperformed not only the original formulation but also more advanced methods, resulting in the second-best explainer with an Ins-Del score of 0.56. Hyper Expected Grad-CAM provided remarkable results across each quantitative metric, yielding a 0.15 increase in insertion when compared to the highest-scoring explainer PolyCAM, totaling to an Ins-Del score of 0.72.

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  • 45.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES).
    Handover in IEEE 802.11p-based delay-sensitive vehicle-to-infrastructure communication2009Report (Other academic)
    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.

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  • 46.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Position-based data traffic prioritization in safety-critical, real-time vehicle-to-infrastructure communication2009In: IEEE International Conference on Communications Workshops, 2009. ICC Workshops 2009 / [ed] IEEE, Piscataway, N.J.: IEEE Press, 2009, p. 205-210Conference paper (Refereed)
    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.

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  • 47.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Kunert, Kristina
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    A fibre-optic AWG-based real-time network for high-performance embedded computing2004Conference paper (Refereed)
    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.

  • 48.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES).
    Kunert, Kristina
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Hoang, Hoai
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    A Fibre-Optic AWG-Based Real-Time Network and Its Applicability to High-Performance Embedded Computing2005In: 19th International Parallel and Distributed Processing Symposium: proceedings, Piscataway, N.J.: IEEE Press, 2005, p. 133b-133b, article id 1419972Conference paper (Refereed)
    Abstract [en]

    In this paper, an architecture and a Medium Access Control (MAC) protocol for a multi-wavelength 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 fixed-tuned 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.

    Download full text (pdf)
    FULLTEXT01
  • 49.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Kunert, Kristina
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Data age based MAC scheme for fast and reliable communication within and between platoons of vehicles2016In: International Conference on Wireless and Mobile Computing, Networking and Communications, Piscataway: IEEE, 2016Conference paper (Refereed)
    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.

  • 50.
    Cheema, Ansar Zaman
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Saqib, Imran Ullah
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Collaborating ISPs Supporting Various Real-Time Services2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    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.

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