hh.sePublications
Change search
Refine search result
1234567 101 - 150 of 459
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 101.
    de Freitas, Edison Pignaton
    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).
    Binotto, Alécio Pedro Delazari
    Fraunhofer IGD / TU Darmstadt, Germany.
    Pereira, Carlos Eduardo
    PPGC UFRGS, Brazil.
    Stork, Andre
    Fraunhofer IGD / TU Darmstadt, Germany.
    Larsson, Tony
    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).
    Dynamic activity and task allocation supporting uav teams in surveillance systems2009In: Proceedings of the International Multiconference on Computer Science and Information Technology, 2009. IMCSIT '09, Piscataway, N.J.: IEEE Press, 2009, p. 51-58Conference paper (Refereed)
    Abstract [en]

    The use of Unmanned Aerial Vehicles is increasing in the field of area patrolling and surveil- lance. A great issue that emerge in designing such systems is the target workload distribution over a fleet of UAVs, which generally have different capabilities of sensing and computing power. Targets should be assigned to the most suitable UAVs in order to efficiently perform the end-user initiated missions. To perform these missions, the UAVs require powerful high-performance platforms to deal with many dif- ferent algorithms that make use of massive calculations. The use of COTS hardware (e.g., GPU) presents an interesting low-cost alternative to compose the required platform. However, in order to efficiently use these heterogeneous platforms in a dynamic scenario, such as in surveillance systems, runtime reconfigu- ration strategies must be provided. This paper presents a dynamic approach to distribute the handling of targets among the UAVs and a heuristic method to address the efficient use of the heterogeneous hard- ware that equips these UAVs, with the goal to meet also mission timing requirements. Preliminary simu- lation results of the proposed heuristics are also provided.

  • 102.
    de Freitas, Edison Pignaton
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Bösch, Bernhard
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Allgayer, Rodrigo
    Electrical Engineering Department, Universidade Federal do Rio Grande do Sul, Brazil.
    Steinfeld, Leonardo
    Electrical Engineering Institute, Universidad de la República, Uruguay.
    Wagner, Flávio
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Carro, Luigi
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Pereira, Carlos
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil; Electrical Engineering Department, Universidade Federal do Rio Grande do Sul, Brazil.
    Larsson, Tony
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Mobile Agents Model and Performance Analysis of a Wireless Sensor Network Target Tracking Application2011In: Smart spaces and next generation wired/wireless networking: 11th International Conference, NEW2AN 2011 and 4th Conference on Smart Spaces, RuSMART 2011, St. Petersburg, Russia, August 22 -25, 2011 ; proceedings / [ed] Sergey Balandin, Heidelberg: Springer Berlin/Heidelberg, 2011, Vol. 6869, p. 274-286Conference paper (Refereed)
    Abstract [en]

    Advances on wireless communication and sensor systems enabled the growing usage of Wireless Sensor Networks. This kind of network is being used to support a number of new emerging applications, thus the importance in studying the efficiency of new approaches to program them. This paper proposes a performance study of an application using high-level mobile agent model for Wireless Sensor Networks. The analysis is based on a mobile object tracking system, a classical WSN application. It is assumed that the sensor nodes are static, while the developed software is implemented as mobile agents by using the AFME framework. The presented project follows a Model-Driven Development (MDD) methodology using UML (Unified Modeling Language) models. Metrics related to dynamic features of the implemented solution are extracted from the deployed application, allowing a design space exploration in terms of metrics such as performance, memory and energy consumption. © Springer-Verlag Berlin Heidelberg 2011.

  • 103.
    de Freitas, Edison Pignaton
    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).
    Heimfarth, Tales
    Computer Science Department UFLA - Brazil.
    Costa, Luiz Augusto Guimarães
    Computer Science Department UFLA - Brazil.
    Ferreira, Armando M.
    Military Institute of Engineering - Brazil.
    Pereira, Carlos Eduardo
    PPGC UFRGS - Brazil.
    Wagner, Flávio Rech
    PPGC UFRGS - Brazil.
    Larsson, Tony
    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).
    Analyzing different levels of geographic context awareness in agent ferrying over VANETs2011In: Proceedings of the 2011 ACM Symposium on Applied Computing, New York: ACM Press, 2011, p. 413-418Conference paper (Refereed)
    Abstract [en]

    The use of mobile software agents is a promising approach to implement services over ad hoc networks. This paper presents an analysis of mobile autonomous agents with different degrees of intelligence that allow them to make usage of the positioning information of vehicle carried sensor nodes with different depth of complexity, considering the nodes’ current and future locations. The agents’ intelligence is used to decide their movement during opportunistic connections among the nodes in order to accomplish missions. In this work, the analysis is done over an application of “virtual sensors”, implemented by services provided by the mobile agents. These agents run on top of an infrastructure-less Vehicular Ad hoc Network (VANET). Simulation results are presented and discussed to support the proposed ideas.

  • 104.
    de Freitas, Edison Pignaton
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES). Institute of Informatics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Heimfarth, Tales
    Institute of Informatics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Pereira, Carlos Eduardo
    Institute of Informatics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Ferreira, Armando Morado
    Electrical Engineering Department, Military Institute of Engineering, Rio de Janeiro, Brazil.
    Wagner, Flávio Rech
    Institute of Informatics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Larsson, Tony
    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).
    Evaluation of coordination strategies for heterogeneous sensor networks aiming at surveillance applications2009In: Sensors 2009 New Zealand: IEEE Sensors 2009 Conference: 25-28 October, 2009, Christchurch, New Zealand, Piscataway, N.J.: IEEE Press, 2009, p. 591-596Conference paper (Refereed)
    Abstract [en]

    A new challenge in the sensor network area is the coordination of heterogeneous sensors (with different sensing, mobility and computing capabilities) in an integrated network. This kind of sensor networks have clearly high relevance in surveillance systems, in which both low-end static ground sensor nodes and more sophisticated sensors carried by mobile platforms, such as Unmanned Aerial Vehicles (UAVs), cooperate. This paper provides an analysis of two different strategies to guide the collaboration among the sensor nodes mentioned above, applied to area surveillance systems. The first analyzed problem is related to the choice of the UAV instance that will respond to a given alarm issued by a ground sensor node. The second issue is the estimation of the response time until any UAV can be engaged in handling an alarm and effectively handles it. Two strategies are introduced and compared: one based on a pheromone inspired approach and another based on utility functions inspired on risk profiles that models decisions of investors in the stock market. ©2009 IEEE.

  • 105.
    Deng, Der-Jiunn
    et al.
    Department of Computer Science and Information Engineering, National Changhua University of Education, Changhua, Taiwan.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Atiquzzaman, Mohammed
    Department of Computer Science, The University of Oklahoma, Norman, OK, United States.
    Editorial: Recent Advances in Heterogeneous Networking for Quality, Reliability, Security and Robustness2017In: Journal on spesial topics in mobile networks and applications, ISSN 1383-469X, E-ISSN 1572-8153, Vol. 22, no 1, p. 1-3Article in journal (Other academic)
  • 106.
    Dillon, Tharam
    et al.
    Curtin University of Technology, Bentley, Australia.
    Parashar, Manish
    Rutgers University, New Jersey, USA.
    Taha, Walid
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Chen, Guolong
    Suzhou University, Jiangsu Sheng, China.
    Zomaya, Albert
    University of Sydney, Sydney, Australia.
    Pan, Yi
    Georgia State University, Georgia, USA.
    Message from U-Science 2014 general chairs2014In: 2014 IEEE 12th International Conference on Dependable, Autonomic and Secure Computing, Piscataway: IEEE, 2014, article id 6945646Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    Presents the introductory welcome message from the conference proceedings. May include the conference officers' congratulations to all involved with the conference event and publication of the proceedings record.© 2014 IEEE

  • 107.
    Dorrell, David G.
    et al.
    University of Technology Sydney, Sydney, New South Wales, Australia.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Cao, Dongpu
    Cranfield University, Bedford, United Kingdom.
    Connected Vehicles – Advancements in Vehicular Technologies and Informatics2015In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 62, no 12, p. 7824-7826, article id 7322333Article in journal (Refereed)
    Abstract [en]

    Vehicles are becoming increasingly more sophisticated and the technology being developed in them covers a number of areas. At the heart of these developments are often the communication, information and control systems. This is very much illustrated in this "Special Section on Connected Vehicles - Advancements in Vehicular Technologies and Informatics" of the IEEE Transactions on Industrial Electronics that we are pleased to present. The Special Section contains twelve papers related to automotive technology. Obviously there a range of areas covered from very high speed machines, that could be used for cooling fans in automotive fuel cells or scaled up for drive motors, to energy management and into various communications aspects of vehicular technology. © 1982-2012 IEEE.

  • 108.
    Duracz, Adam
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Rigorous Simulation: Its Theory and Applications2016Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Designing Cyber-Physical Systems is hard. Physical testing can be slow, expensive and dangerous. Furthermore computational components make testing all possible behavior unfeasible. Model-based design mitigates these issues by making it possible to iterate over a design much faster. Traditional simulation tools can produce useful results, but their results are traditionally approximations that make it impossible to distinguish a useful simulation from one dominated by numerical error. Verification tools require skills in formal specification and a priori understanding of the particular dynamical system being studied.

    This thesis presents rigorous simulation, an approach to simulation that uses validated numerics to produce results that quantify and bound all approximation errors accumulated during simulation. This makes it possible for the user to objectively and reliably distinguish accurate simulations from ones that do not provide enough information to be useful. Explicitly quantifying the error in the output has the side-effect of leading to a tool for dealing with inputs that come with quantified uncertainty.

    We formalize the approach as an operational semantics for a core subset of the domain-specific language Acumen. The operational semantics is extended to a larger subset through a translation. Preliminary results toward proving the soundness of the operational semantics with respect to a denotational semantics are presented. A modeling environment with a rigorous simulator based on the operational semantics is described. The implementation is portable, and its source code is freely available. The accuracy of the simulator on different kinds of systems is explored through a set of benchmark models that exercise different aspects of a rigorous simulator. A case study from the automotive domain is used to evaluate the applicability of the simulator and its modeling language. In the case study, the simulator is used to compute rigorous bounds on the output of a model.

  • 109.
    Duracz, Adam
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Bartha, Ferenc Ágoston
    Rice University, Houston, TX, USA.
    Taha, Walid
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Rice University, Houston, TX, USA.
    Accurate Rigorous Simulation Should be Possible for Good Designs2016In: Proceedings of the 2016 International Workshop on Symbolic and Numerical Methods for Reachability Analysis (SNR) / [ed] Erika Ábrahám & Sergiy Bogomolov, Piscataway, NJ: IEEE conference proceedings, 2016, article id 7479376Conference paper (Refereed)
    Abstract [en]

    The development of Cyber-Physical Systems benefits from better methods and tools to support the simulation and verification of hybrid (continuous/discrete) models. Acumen is an open source testbed for exploring the design space of what rigorous-but-practical next-generation tools can deliver to developers. Central to Acumen is the notion of rigorous simulation. Like verification tools, rigorous simulation is intended to provide guarantees about the behavior of the system. Like traditional simulation tools, it is intended to be intuitive, practical, and scalable. Whether these two goals can be achieved simultaneously is an important, long-term challenge.

    This paper proposes a design principle that can play an important role in meeting this challenge. The principle addresses the criticism that accumulating numerical errors is a serious impediment to practical rigorous simulation. It is inspired by a twofold insight: one relating to the nature of systems engineered in the real world, and the other relating to how numerical errors in the simulation of a model can be recast as errors in the state or parameters of the model in the simulation. We present a suite of small, concrete benchmarks that can be used to assess the extent to which a rigorous simulator upholds the proposed principle. We also report on which benchmarks Acumen's current rigorous simulator already succeeds and which ones remain challenging.

  • 110.
    Duracz, Adam
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Eriksson, Henrik
    SP Technical Research Institute of Sweden, Borås, Sweden.
    Bartha, Ferenc Ágoston
    Rice University, Houston TX, USA.
    Zeng, Yingfu
    Rice University, Houston TX, USA.
    Xu, Fei
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Taha, Walid
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Rice University, Houston TX, USA.
    Using Rigorous Simulation to Support ISO 26262 Hazard Analysis and Risk Assessment2015In: 2015 IEEE 12th International Conference on Embedded Software and Systems (ICESS) / [ed] Meikang Qiu, Yongxin Zhu, Daikai Zhu & Fengling Han, Piscataway, N.J.: IEEE Press, 2015, p. 1093-1096Conference paper (Refereed)
    Abstract [en]

    Rigorous simulation is a new technology that can play a key role in managing uncertainty in the design of safety-critical cyber-physical systems. One of its important applications is the analysis and evaluation of functional safety for road vehicles according to international standards such as ISO 26262. Previous work  presented preliminary evidence to support the feasibility of using rigorous simulation for this purpose. Here we report on advances in our implementation of rigorous simulation and show how they enable the rigorous simulation of more refined and more complete models. A larger case study highlights the benefits of these advances and helps us identify new challenges that should be addressed by future work. © 2015 IEEE.

  • 111.
    Duracz, Adam
    et al.
    Rice University, Houston, TX, United States.
    Moggi, Eugenio
    DIBRIS, Genova University, Genova, Italy.
    Taha, Walid
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Lin, Zhenchao
    Zhejiang University, Hangzhou, China.
    A Semantic Account of Rigorous Simulation2018In: Principles of Modeling: Essays Dedicated to Edward A. Lee on the Occasion of His 60th Birthday / [ed] Marten LohstrohPatricia DerlerMarjan Sirjani, Amsterdam: Springer Berlin/Heidelberg, 2018, Vol. 10760, p. 223-239Chapter in book (Refereed)
    Abstract [en]

    Hybrid systems are a powerful formalism for modeling cyber-physical systems. Reachability analysis is a general method for checking safety properties, especially in the presence of uncertainty and non-determinism. Rigorous simulation is a convenient tool for reachability analysis of hybrid systems. However, to serve as proof tool, a rigorous simulator must be correct w.r.t. a clearly defined notion of reachability, which captures what is intuitively reachable in finite time. As a step towards addressing this challenge, this paper presents a rigorous simulator in the form of an operational semantics and a specification in the form of a denotational semantics. We show that, under certain conditions about the representation of enclosures, the rigorous simulator is correct. We also show that finding a representation satisfying these assumptions is non-trivial. © 2018, Springer International Publishing AG, part of Springer Nature.

  • 112. Duracz, Jan
    et al.
    Farjudian, Amin
    University of Nottingham Ningbo China, Ningbo, China.
    Konečný, Michal
    Aston University, Birmingham, United Kingdom.
    Taha, Walid
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Rice University, Houston, Texas, USA.
    Function Interval Arithmetic2014In: Mathematical software -- ICMS 2014: 4th International Congress, Seoul, South Korea, August 5-9, 2014. Proceedings / [ed] Hoon Hong & Chee Yap, Berlin, Heidelberg: Springer, 2014, p. 677-684Conference paper (Refereed)
    Abstract [en]

    We propose an arithmetic of function intervals as a basis for convenient rigorous numerical computation. Function intervals can be used as mathematical objects in their own right or as enclosures of functions over the reals. We present two areas of application of function interval arithmetic and associated software that implements the arithmetic: (1) Validated ordinary differential equation solving using the AERN library and within the Acumen hybrid system modeling tool. (2) Numerical theorem proving using the PolyPaver prover. © 2014 Springer-Verlag.

  • 113.
    Duracz, Jan
    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).
    Konečný, Michal
    School of Engineering and Applied Science, Aston University, Birmingham, United Kingdom.
    Polynomial Function Intervals for Floating-Point Software Verification2014In: Annals of Mathematics and Artificial Intelligence, ISSN 1012-2443, E-ISSN 1573-7470, Vol. 70, no 4, p. 351-398Article in journal (Refereed)
    Abstract [en]

    The focus of our work is the verification of tight functional properties of numerical programs, such as showing that a floating-point implementation of Riemann integration computes a close approximation of the exact integral. Programmers and engineers writing such programs will benefit from verification tools that support an expressive specification language and that are highly automated. Our work provides a new method for verification of numerical software, supporting a substantially more expressive language for specifications than other publicly available automated tools. The additional expressivity in the specification language is provided by two constructs. First, the specification can feature inclusions between interval arithmetic expressions. Second, the integral operator from classical analysis can be used in the specifications, where the integration bounds can be arbitrary expressions over real variables. To support our claim of expressivity, we outline the verification of four example programs, including the integration example mentioned earlier. A key component of our method is an algorithm for proving numerical theorems. This algorithm is based on automatic polynomial approximation of non-linear real and real-interval functions defined by expressions. The PolyPaver tool is our implementation of the algorithm and its source code is publicly available. In this paper we report on experiments using PolyPaver that indicate that the additional expressivity does not come at a performance cost when comparing with other publicly available state-of-the-art provers. We also include a scalability study that explores the limits of PolyPaver in proving tight functional specifications of progressively larger randomly generated programs.

  • 114.
    Díez Rodríguez, Victor
    et al.
    Halmstad University, School of Information Technology.
    Detournay, Jérôme
    Halmstad University, School of Information Technology.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Lyamin, Nikita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    An Approach for Receiver-Side Awareness Control in Vehicular Ad Hoc Networks2018In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 19, no 4, p. 1227-1236Article in journal (Refereed)
    Abstract [en]

    Vehicular Ad hoc networks (VANET) are a key element of cooperative intelligent transport systems. One of the challenges in VANETs is dealing with awareness and congestion due to the high amount of messages received from the vehicles in communication range. As VANETs are used in critical applications, congestion on the receiver side caused by the buffering of the packets is a safety hazard. In this paper, we propose a streamwise queuing system on the receiver side and show how it improves the timeliness of the messages received and maintains the awareness of the system in a congestion situation. © Copyright 2017 IEEE

  • 115.
    Eckhoff, David
    et al.
    University of Erlangen.
    Festag, Andreas
    University of Dresden.
    Gruteser, Marco
    Rutgers University.
    Schimandl, Florian
    Technische Universität München.
    Segata, Michele
    University of Innsbruck.
    Uhlemann, Elisabeth
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Best practices for field operational testing2014In: Inter-Vehicular Communications – Quo Vadis: Report from Dagstuhl Seminar 13392 / [ed] Onur Altintas, Falko Dressler, Hannes Hartenstein and Ozan K. Tonguz, Dagstuhl, Germany: Schloss Dagstuhl, Leibniz-Zentrum fuer Informatik , 2014, p. 206-209Chapter in book (Other academic)
  • 116.
    Emamizadeh, B.
    et al.
    School of Mathematical Sciences, The University of Nottingham Ningbo, China.
    Farjudian, Amin
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Liu, Y.
    Beijing International Center for Mathematical Research, Peking University, China.
    Optimal harvesting strategy based on rearrangements of functions2018In: Applied Mathematics and Computation, ISSN 0096-3003, E-ISSN 1873-5649, Vol. 320, p. 677-690Article in journal (Refereed)
    Abstract [en]

    We study the problem of optimal harvesting of a marine species in a bounded domain, with the aim of minimizing harm to the species, under the general assumption that the fishing boats have different capacities. This is a generalization of a result of Kurata and Shi, in which the boats were assumed to have the same maximum harvesting capacity. For this generalization, we need a completely different approach. As such, we use the theory of rearrangements of functions. We prove existence of solutions, and obtain an optimality condition which indicates that the more aggressive harvesting must be pushed toward the boundary of the domain. Furthermore, we prove that radial and Steiner symmetries of the domain are preserved by the solutions. We will also devise an algorithm for numerical solution of the problem, and present the results of some numerical experiments. © 2017 Elsevier Inc.

  • 117.
    Emamizadeh, Behrouz
    et al.
    School of Mathematical Sciences, The University of Nottingham Ningbo, China.
    Farjudian, Amin
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Existence and uniqueness of solutions for nonlocal p-Laplacian problems2016In: Electronic Journal of Differential Equations, ISSN 1550-6150, E-ISSN 1072-6691, Vol. 2016, no 274, p. 1-9Article in journal (Refereed)
    Abstract [en]

    We study the existence and uniqueness of positive solutions to a class of nonlocal boundary-value problems involving the p-Laplacian. Our main tools are a variant of the Schaefer's fixed point theorem, an inequality which suitably handles the p-Laplacian operator, and a Sobolev embedding which is applicable to the bounded domain. © 2016 Texas State University.

  • 118.
    Emamizadeh, Behrouz
    et al.
    The University of Nottingham Ningbo, Ningbo, China.
    Farjudian, Amin
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Mikayelyan, Hayk
    The University of Nottingham Ningbo, Ningbo, China.
    An Elliptic Optimal Control Problem and its Two Relaxations2017In: Journal of Optimization Theory and Applications, ISSN 0022-3239, E-ISSN 1573-2878, Vol. 172, no 2, p. 455-465Article in journal (Refereed)
    Abstract [en]

    In this note, we consider a control theory problem involving a strictly convex energy functional, which is not Gâteaux differentiable. The functional came up in the study of a shape optimization problem, and here we focus on the minimization of this functional. We relax the problem in two different ways and show that the relaxed variants can be solved by applying some recent results on two-phase obstacle-like problems of free boundary type. We derive an important qualitative property of the solutions, i.e., we prove that the minimizers are three-valued, a result which significantly reduces the search space for the relevant numerical algorithms. © 2016, Springer Science+Business Media New York.

  • 119.
    Emamizadeh, Behrouz
    et al.
    School of Mathematical Sciences, The University of Nottingham Ningbo, Ningbo, China.
    Farjudian, Amin
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Zivari-Rezapour, Mohsen
    Department of Mathematics, Faculty of Mathematical Sciences & Computer, Shahid Chamran University, Ahvaz, Iran.
    Optimization Related to Some Nonlocal Problems of Kirchhoff Type2016In: Canadian Journal of Mathematics - Journal Canadien de Mathematiques, ISSN 0008-414X, E-ISSN 1496-2479, Vol. 68, no 3, p. 521-540Article in journal (Refereed)
    Abstract [en]

    In this paper we introduce two rearrangement optimization problems, one being a maximization and the other a minimization problem, related to a nonlocal boundary value problem of Kirchhoff type. Using the theory of rearrangements as developed by G. R. Burton we are able to show that both problems are solvable, and derive the corresponding optimality conditions. These conditions in turn provide information concerning the locations of the optimal solutions. The strict convexity of the energy functional plays a crucial role in both problems. The popular case in which the rearrangement class (i.e., the admissible set) is generated by a characteristic function is also considered. We show that in this case, the maximization problem gives rise to a free boundary problem of obstacle type, which turns out to be unstable. On the other hand, the minimization problem leads to another free boundary problem of obstacle type, which is stable. Some numerical results are included to confirm the theory.

  • 120.
    Essayas, Gebrewahid
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Yang, Mingkun
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Cedersjö, Gustav
    Department of Computer Science, Lund University, Lund, Sweden.
    Ul-Abdin, Zain
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Gaspes, Veronica
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Janneck, Jörn W.
    Department of Computer Science, Lund University, Lund, Sweden.
    Svensson, Bertil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Realizing Efficient Execution of Dataflow Actors on Manycores2014In: Proceedings: 2014 International Conference on Embedded and Ubiquitous Computing: EUC 2014: August 2014, Milano, Italy / [ed] Randall Bilof, Los Alamitos, CA: IEEE Computer Society, 2014, p. 321-328, article id 6962305Conference paper (Refereed)
    Abstract [en]

    Embedded DSP computing is currently shifting towards manycore architectures in order to cope with the ever growing computational demands. Actor based dataflow languages are being considered as a programming model. In this paper we present a code generator for CAL, one such dataflow language. We propose to use a compilation tool with two intermediate representations. We start from a machine model of the actors that provides an ordering for testing of conditions and firing of actions. We then generate an Action Execution Intermediate Representation that is closer to a sequential imperative language like C and Java. We describe our two intermediate representations and show the feasibility and portability of our approach by compiling a CAL implementation of the Two-Dimensional Inverse Discrete Cosine Transform on a general purpose processor, on the Epiphany manycore architecture and on the Ambric massively parallel processor array. © 2014 IEEE.

  • 121.
    Evdokimova, Ekaterina
    et al.
    Department of Telecommunications and Information, Ghent University, Gent, Belgium.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Department of Electrical Engineering, Western Norway University of Applied Sciences, Bergen, Norway.
    Lyamin, Nikita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Fiems, Dieter
    Department of Telecommunications and Information, Ghent University, Gent, Belgium.
    Internet Provisioning in VANETs: Performance Modeling of Drive-Thru Scenarios2019In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, p. 1-15Article in journal (Refereed)
    Abstract [en]

    Drive-thru-Internet is a scenario in cooperative intelligent transportation systems (C-ITSs), where a road-side unit (RSU) provides multimedia services to vehicles that pass by. Performance of the drive-thru-Internet depends on various factors, including data traffic intensity, vehicle traffic density, and radio-link quality within the coverage area of the RSU, and must be evaluated at the stage of system design in order to fulfill the quality-of-service requirements of the customers in C-ITS. In this paper, we present an analytical framework that models downlink traffic in a drive-thru-Internet scenario by means of a multidimensional Markov process: the packet arrivals in the RSU buffer constitute Poisson processes and the transmission times are exponentially distributed. Taking into account the state space explosion problem associated with multidimensional Markov processes, we use iterative perturbation techniques to calculate the stationary distribution of the Markov chain. Our numerical results reveal that the proposed approach yields accurate estimates of various performance metrics, such as the mean queue content and the mean packet delay for a wide range of workloads. © 2019 IEEE.

  • 122.
    Fan, Xing
    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).
    Real-Time Services in Packet-Switched Networks for Embedded Applications2007Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Embedded applications have become more and more complex, increasing the demands on the communication network. For reasons such as safety and usability, there are real-time constraints that must be met. Also, to offer high performance, network protocols should offer efficient user services aimed at specific types of communication.

    At the same time, it is desirable to design and implement embedded networks with reduced cost and development time, which means using available hardware for standard networks. To that end, there is a trend towards using switched Ethernet for embedded systems because of its hight bit rate and low cost. Unfortunately, since switched Ethernet is not specifically designed for embedded systems, it has several limitations such as poor support for QoS because of FCFS queuing policy and high protocol overhead.

    This thesis contributes towards fulfilling these requirements by developing (i) real-time analytical frameworks for providing QoS guarantees in packet-switched networks and (II) packet-merging techniques to reduce the protocol overhead.

    We have developed two real-time analytical frameworks for networks with FCFS queuing in the switches, one for FCFS queuing in the source nodes and one for EDF queuing in the source nodes. The correctness and tightness of the real-time analytical frameworks for different network components in a singel-switch neetwork are given by strict theoretical proofs, and the performance of our end-to-end analyses is evaluated by simulations. In conjunction with this, we have compared our results to Network Calculus (NC), a commonly used analytical scheme for FCFS queuing. Our comparison study shows that our anlysis is more accurate than NC for singel-switch networks.

    To reduce the protocol overhead, we have proposed two active switched Ethernet approaches, one for real-time many-to-many communication and the other for the real-time short message traffic that is often present in embedded applications. A significant improvement in performance achieved by using our proposed active networks is demonstrated.

    Although our approaches are exemplified using switched Ethernet, the general approaches are not limited to switched Ethernet networks but can easily be moified to other similar packet-switched networks.

  • 123.
    Fan, Xing
    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), Centre for Research on Embedded Systems (CERES).
    Efficient Support for High Traffic-Volumes of Short-Message Real-Time Communication Using an Active Ethernet Switch2004In: Proceedings of the 10th International Conference on Real-time and Embedded Computing Systems and Applications (RTCSA’04), 2004, p. 517-533Conference paper (Refereed)
    Abstract [en]

    There are several different types of communication traffic with real- time demands apparent in distributed industrial and embedded systems, for example, group communication and process synchronization. The length of these messages is often very short but the traffic volume might be really high. Standard network protocols do not normally reach very high utilization for such small messages. This paper presents a solution to efficiently support real-time short message communication over switched Ethernet. In our proposal, the Ethernet switch and the end-nodes are enhanced to combine several short messages into an Ethernet frame to improve the performance, and to give the short-message traffic real-time support on two levels, short-frame level and Ethernet frame level. Earliest Deadline First (EDF) scheduling is used in the switch and in the source nodes on both these two levels. We have characterized the performance of the network in terms of channel utilization and the number of accepted real-time channels, by simulations of the network assuming Fast Ethernet. We also show, by example, that we can reach an improvement of the possible short-message rate of 66%.

  • 124.
    Fan, Xing
    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).
    Guaranteed real-time services over standard switched Ethernet2005In: The IEEE Conference on Local Computer Networks, 30th Anniversary: proceedings, Sydney, Australia, November 15-17, 2005, New York, NY: IEEE Computer Society, 2005, p. 490-492Conference paper (Refereed)
    Abstract [en]

    In this paper, we contribute with an approach to support guaranteed real-time services over standard switched Ethernet without 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 that can be used 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. The simulation analysis verifies our feasibility analysis.

  • 125.
    Fiems, Dieter
    et al.
    Ghent University, Ghent, Belgium.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Connectivity Times in Vehicular Networks2018In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 22, no 11, p. 2270-2273, article id 8444968Article in journal (Refereed)
    Abstract [en]

    We propose an analytical model that accurately captures the service advertisement and access mechanisms in IEEE 1609.4/IEEE 802.11p multi-channel vehicular networks where road-side units announce non-safety services to passing vehicles on a dedicated channel. For a drive-thru scenario, we calculate various performance measures including the service discovery probability, the mean time till discovery and the channel utilization. © 1997-2012 IEEE.

  • 126.
    Forsberg, Håkan
    et al.
    Department of Computer Engineering, Chalmers University of Technology, Göteborg, Sweden.
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Svensson, Bertil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Opportunities for Optical Planar Interconnection Technology in Terabit Switches2003In: Proceedings of the IASTED International Conference on Wireless and Optical Communications, July 2-4, 2003, Banff, Canada / [ed] Lambertus Hesselink, Anaheim; Calgary: ACTA Press , 2003, p. 155-164Conference paper (Refereed)
    Abstract [en]

    To keep up with the explosive growth of world-wide network traffic, large-capacity switches, with switching capacities in excess of several terabits per second, are becoming an essential part of the future. To realize such switches, new architecture concepts must be considered. In this paper, we discuss a technology for terabit switches that combines the advantage of using optical communication in all three spatial dimensions and the benefits of using surface mounted optoelectronic as well as electronic chips. We present three different types of packet-based switch fabrics, all based on the optical planar interconnection technology. We then discuss these in terms of capacity, scalability, and physical size. All three implementations have a single switch plane cross sectional bandwidth exceeding 5 Tbps.

  • 127.
    Fragal, Vanderson Hafemann
    et al.
    University of Sao Paulo, Sao Carlos, Brazil.
    Simao, Adenilso
    University of Sao Paulo, Sao Carlos, Brazil.
    Endo, Andre Takeshi
    Federal University of Paraná, Curitiba, Paraná, Brazil.
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Reducing the Concretization Effort in FSM-Based Testing of Software Product Lines2017In: 10th IEEE International Conference on Software Testing, Verification and Validation Workshops - ICSTW 2017 / [ed] Randall Bilof, Los Alamitos, CA: IEEE , 2017, p. 329-336Conference paper (Refereed)
    Abstract [en]

    To test a Software Product Line (SPL), the test artifacts and the techniques must be extended to support variability. In general, when new SPL products are developed, more tests are generated to cover new or modified features. A dominant source of extra effort for such tests is the concretization of newly generated tests. Thus, minimizing the amount of new non-concretized tests required to perform conformance testing on new products reduces the overall test effort. In this paper, we propose a test reuse strategy for conformance testing of SPL products that aims at reducing test effort. We use incremental test generation methods based on finite state machines (FSMs) to maximize test reuse. We combine these methods with a selection algorithm used to identify non-redundant concretized tests. We illustrate our strategy using examples and a case study with an embedded mobile SPL. The results indicate that our strategy can save up to 36% of test effort in comparison to current test reuse strategies for the same fault detection capability. © 2017 IEEE.

  • 128.
    Fragal, Vanderson Hafemann
    et al.
    University of São Paolo, São Carlos, Brazil.
    Simao, Adenilso
    University of São Paolo, São Carlos, Brazil.
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Validated Test Models for Software Product Lines: Featured Finite State Machines2016In: Formal Aspects of Component Software: 13th International Conference, FACS 2016, Besançon, France, October 19-21, 2016, Revised Selected Papers / [ed] Kouchnarenko, Olga & Khosravi, Ramtin, Cham: Springer, 2016, Vol. 10231, p. 210-227Conference paper (Refereed)
    Abstract [en]

    Variants of the finite state machine (FSM) model have been extensively used to describe the behaviour of reactive systems. In particular, several model-based testing techniques have been developed to support test case generation and test case executions from FSMs. Most such techniques require several validation properties to hold for the underlying test models. In this paper, we propose an extension of the FSM test model for software product lines (SPLs), named featured finite state machine (FFSM). As the first step towards using FFSMs as test models, we define feature-oriented variants of basic test model validation criteria. We show how the high-level validation properties coincide with the necessary properties on the product FSMs. Moreover, we provide a mechanised tool prototype for checking the feature-oriented properties using satisfiability modulo theory (SMT) solver tools. We investigate the applicability of our approach by applying it to both randomly generated FFSMs as well as those from a realistic case study (the Body Comfort System). The results of our study show that for random FFSMs over 16 independent non-mandatory features, our technique provides substantial efficiency gains for the set of proposed validity checks. © Springer International Publishing AG 2017

  • 129.
    Friel, Ross
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Gerling-Gedin, Maria
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Nilsson, Emil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab. Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES).
    Andreasson, Björn Pererik
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    3D Printed Radar Lenses with Anti-Reflective Structures2019In: Designs, E-ISSN 2411-9660, Vol. 3, no 2, article id 28Article in journal (Refereed)
    Abstract [en]

    Background: The purpose of this study was to determine if 3D printed lenses with wavelength specific anti-reflective (AR) surface structures would improve beam intensity and thus radar efficiency for a Printed Circuit Board (PCB)-based 60 GHz radar. This would have potential for improved low-cost radar lenses for the consumer product market. Methods: A hyperbolic lens was designed in 3D Computer Aided Design (CAD) software and was then modified with a wavelength specified AR structure. Electromagnetic computer simulation was performed on both the ‘smooth’ and ‘AR structure’ lenses and compared to actual 60 GHz radar measurements of 3D printed polylactic acid (PLA) lenses. Results: The simulation results showed an increase of 10% in signal intensity of the AR structure lens over the smooth lens. Actual measurement showed an 8% increase in signal of the AR structure lens over the smooth lens. Conclusions: Low cost and readily available Fused Filament Fabrication (FFF) 3D printing has been shown to be capable of printing an AR structure coated hyperbolic lens for millimeter wavelength radar applications. These 3D Printed AR structure lenses are effective in improving radar measurements over non-AR structure lenses.

  • 130.
    Ganjalizadeh, Milad
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Reliability for Hard Real-time Communication in Packet-switched Networks2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowadays, different companies use Ethernet for different industrial applications. Industrial Ethernet has some specific requirements due to its specific applications and environmental conditions which is the reason that makes it different than corporate LANs. Real-time guarantees, which require precise synchronization between all communication devices, as well as reliability are the keys in performance evaluation of different methods [1].  High bandwidth, high availability, reduced cost, support for open infrastructure as well as deterministic architecture make packet-switched networks suitable for a variety of different industrial distributed hard real-time applications. Although research on guaranteeing timing requirements in packet-switched networks has been done, communication reliability is still an open problem for hard real-time applications.

    In this thesis report, a framework for enhancing the reliability in multihop packet-switched networks is presented. Moreover, a novel admission control mechanism using a real-time analysis is suggested to provide deadline guarantees for hard real-time traffic. A generic and flexible simulator has been implemented for the purpose of this research study to measure different defined performance metrics. This simulator can also be used for future research due to its flexibility. The performance evaluation of the proposed solution shows a possible enhancement of the message error rate by several orders of magnitude, while the decrease in network utilization stays at a reasonable level.

  • 131.
    Ganjalizadeh, Milad
    et al.
    Halmstad University, School of Information Technology.
    Jonsson, Magnus
    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).
    Reliability Enhancement for Hard Real-Time Communication in Industrial Packet-Switched Networks2014In: Multiple Access Communications: 7th International Workshop, MACOM 2014, Halmstad, Sweden, August 27-28, 2014. Proceedings / [ed] Magnus Jonsson, Alexey Vinel, Boris Bellalta & Evgeny Belyaev, Cham: Springer, 2014, Vol. 8715, p. 59-74Conference paper (Refereed)
    Abstract [en]

    Large industrial control and automation applications require reliable communication with strict timing constraints between distributed communication equipment. Packet-switched networks are widely used as a high-speed, deterministic, and low-cost solution to handle these types of distributed real-time systems. Although research on guaranteeing timing requirements in packet-switched networks has been done, communication reliability is still an open problem for hard real-time applications. In this paper, a framework for enhancing the reliability in multihop packet-switched networks is presented. Moreover, an admission control mechanism using a real-time analysis is suggested to provide deadline guarantees for hard real-time traffic. The performance evaluation of the proposed solution shows a possible enhancement of the message error rate by several orders of magnitude while the decrease in network utilization stays at a reasonable level. © Springer International Publishing Switzerland 2014

  • 132.
    Garcia, Alejandro
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Johansson, Lisbeth
    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), Centre for Research on Embedded Systems (CERES).
    Weckstén, Mattias
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Guaranteed periodic real-time communication over wormhole switched networks2000In: 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, p. 632-639Conference paper (Refereed)
    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.

  • 133.
    Gebler, Daniel
    et al.
    Vrije Universiteit, Amsterdam, The Netherlands.
    Goriac, Eugen-Ioan
    Reykjavik University, Reyjkjavik, Iceland.
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Algebraic Meta-Theory of Processes with Data2013In: Proceedings Combined 20th International Workshop on Expressiveness in Concurrency and 10th Workshop on Structural Operational Semantics / [ed] Johannes Borgström & Bas Luttik, Open Publishing Association , 2013, p. 63-77Conference paper (Refereed)
    Abstract [en]

    There exists a rich literature of rule formats guaranteeing different algebraic properties for formalisms with a Structural Operational Semantics. Moreover, there exist a few approaches for automatically deriving axiomatizations characterizing strong bisimilarity of processes. To our knowledge, this literature has never been extended to the setting with data (e.g. to model storage and memory). We show how the rule formats for algebraic properties can be exploited in a genericmanner in the setting with data. Moreover, we introduce a new approach for deriving sound and ground-complete axiom schemata for a notion of bisimilarity with data, called stateless bisimilarity, based on intuitive auxiliary function symbols for handling the store component. We do restrict, however, the axiomatization to the setting where the store component is only given in terms of constants. © Gebler, Goriac & Mousavi.

  • 134.
    Gebrewahid, Essayas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Compiling Concurrent Programs for Manycores2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The arrival of manycore systems enforces new approaches for developing applications in order to exploit the available hardware resources. Developing applications for manycores requires programmers to partition the application into subtasks, consider the dependence between the subtasks, understand the underlying hardware and select an appropriate programming model. This is complex, time-consuming and prone to error.

    In this thesis, we identify and implement abstraction layers in compilation tools to decrease the burden of the programmer, increase programming productivity and program portability for manycores and to analyze their impact on performance and efficiency. We present compilation frameworks for two concurrent programming languages, occam-pi and CAL Actor Language, and demonstrate the applicability of the approach with application case-studies targeting these different manycore architectures: STHorm, Epiphany and Ambric.

    For occam-pi, we have extended the Tock compiler and added a backend for STHorm. We evaluate the approach using a fault tolerance model for a four stage 1D-DCT algorithm implemented by using occam-pi’s constructs for dynamic reconfiguration, and the FAST corner detection algorithm which demonstrates the suitability of occam-pi and the compilation framework for data-intensive applications. We also present a new CAL compilation framework which has a front end, two intermediate representations and three backends: for a uniprocessor, Epiphany, and Ambric. We show the feasibility of our approach by compiling a CAL implementation of the 2D-IDCT for the three backends. We also present an evaluation and optimization of code generation for Epiphany by comparing the code generated from CAL with a hand-written C code implementation of 2D-IDCT.

  • 135.
    Gebrewahid, Essayas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Tools to Compile Dataflow Programs for Manycores2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The arrival of manycore systems enforces new approaches for developing applications in order to exploit the available hardware resources. Developing applications for manycores requires programmers to partition the application into subtasks, consider the dependence between the subtasks, understand the underlying hardware and select an appropriate programming model. This is complex, time-consuming and prone to error. In this thesis, we identify and implement abstraction layers in compilation tools to decrease the burden of the programmer, increase program portability and scalability, and increase retargetability of the compilation framework. We present compilation frameworks for two concurrent programming languages, occam-pi and CAL Actor Language, and demonstrate the applicability of the approach with application case-studies targeting these different manycore architectures: STHorm, Epiphany, Ambric, EIT, and ePUMA. For occam-pi, we have extended the Tock compiler and added a backend for STHorm. We evaluate the approach using a fault tolerance model for a four stage 1D-DCT algorithm implemented by using occam-pi's constructs for dynamic reconguration, and the FAST corner detection algorithm which demonstrates the suitability of occam-pi and the compilation framework for data-intensive applications. For CAL, we have developed a new compilation framework, namely Cal2Many. The Cal2Many framework has a front end, two intermediate representations and four backends: for a uniprocessor, Epiphany, Ambric, and a backend for SIMD based architectures. Also, we have identied and implemented of CAL actor fusion and fission methodologies for efficient mapping CAL applications. We have used QRD, FAST corner detection, 2D-IDCT, and MPEG applications to evaluate our compilation process and to analyze the limitations of the hardware.

  • 136.
    Gebrewahid, Essayas
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Ali Arslan, Mehmet
    Lund University, Lund, Sweden.
    Karlsson, Andreas
    Linköping University, Linköping, Sweden.
    Ul-Abdin, Zain
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Support for Data Parallelism in the CAL Actor Language2016In: WPMVP '16: Proceedings of the 3rd Workshop on Programming Models for SIMD/Vector Processing / [ed] Jan Eitzinger, Joel Falcou, Illie Gabriel Tanase & James Brodman, New York, NY: ACM Press, 2016Conference paper (Refereed)
    Abstract [en]

    With the arrival of heterogeneous manycores comprising various features to support task, data and instruction-level parallelism, developing applications that take full advantage of the hardware parallel features has become a major challenge. In this paper, we present an extension to our CAL compilation framework (CAL2Many) that supports data parallelism in the CAL Actor Language. Our compilation framework makes it possible to program architectures with SIMD support using high-level language and provides efficient code generation. We support general SIMD instructions but the code generation backend is currently implemented for two custom architectures, namely ePUMA and EIT. Our experiments were carried out for two custom SIMD processor architectures using two applications.

    The experiment shows the possibility of achieving performance comparable to hand-written machine code with much less programming effort.

  • 137.
    Gebrewahid, Essayas
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Ul-Abdin, Zain
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Actor Fission Transformations for Executing Dataflow Programs on Manycores2017In: 2017 Forum on Specification and Design Languages (FDL), 2017Conference paper (Other academic)
    Abstract [en]

    Manycore architectures are dominating the development of advanced embedded computing due to the computational and power demand of high performance applications. This has introduced an additional complexity with regard to the efficient exploitation of the underlying hardware and the development of efficient parallel implementations. To tackle this we model applications using a dataflow programming language, perform high-level transformations of dataflow actors, and generate native code by using our compilation framework.This paper presents the actor fission transformations of our Cal2Many compilation framework. The transformations have facilitated the mapping of big dataflow actors on memory restricted embedded manycores, increased the utilization of the hardware, and enabled support for task and data-level parallelism. We have applied the actor transformations to two blocks of MPEG-4 decoder and executed it on the Epiphany manycore architecture. The result shows the practicality and feasibility of our approach.

  • 138.
    Gebrewahid, Essayas
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Ul-Abdin, Zain
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Gaspes, Veronica
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Cal2Many: A Framework to Compile Dataflow Programs for Manycores2017Manuscript (preprint) (Other academic)
    Abstract [en]

    The arrival of manycore platforms has imposed programming challenges for mainstream embedded system developers. In this paper, we discuss the significance of actor-oriented dataflow languages and present our compilation framework for CAL Actor Language that leads to increased portability and retargetability. We demonstrate the applicability of our approach with streaming applications targeting the Epiphany many-core architecture. We have performed an in-depth analysis of MPEG-4 SP implemented on Epiphany using our framework and studied the effects of actor composition. We have identified hardware aspects such as increased off-chip memory bandwidth and larger local memories that could result in further performance improvements.

  • 139.
    Gebrewahid, Essayas
    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).
    Ul-Abdin, Zain
    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).
    Mapping Occam-pi programs to a Manycore Architecture2011Conference paper (Refereed)
    Abstract [en]

    Efficient utilization of available resources is a key concept in embedded systems. This paper is focused on providing the support for managing dynamic reconfiguration of computing resources in the programming model. We present an approach to map occam-pi programs to a manycore architecture, Platform 2012 (P2012). We describe the techniques used to translate the salient features of the occam-pi language to the native programing model of the P2012 architecture. We present the initial results from a case study of matrix multiplication. Our results show the simplicity of occam-pi program by 6 times reduction in lines-of-code.

  • 140.
    Gebrewahid, Essayas
    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).
    Ul-Abdin, Zain
    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).
    Gaspes, Veronica
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Jego, Bruno
    ST-Microlectronics, Grenoble, France.
    Lavigueur, Bruno
    ST-Microlectronics, Grenoble, France.
    Robart, Mathieu
    ST-Microlectronics, Bristol, United Kingdom.
    Programming Real-time Image Processing for Manycores in a High-level Language2013In: Advanced Parallel Processing Technology / [ed] Wu, Chenggang and Cohen, Albert, Berlin Heidelberg: Springer Berlin/Heidelberg, 2013, p. 381-395Conference paper (Refereed)
    Abstract [en]

    Manycore architectures are gaining attention as a means to meet the performance and power demands of high-performance embedded systems. However, their widespread adoption is sometimes constrained by the need formastering proprietary programming languages that are low-level and hinder portability. We propose the use of the concurrent programming language occam-pi as a high-level language for programming an emerging class of manycore architectures. We show how to map occam-pi programs to the manycore architecture Platform 2012 (P2012). We describe the techniques used to translate the salient features of the language to the native programming model of the P2012. We present the results from a case study on a representative algorithm in the domain of real-time image processing: a complex algorithm for corner detectioncalled Features from Accelerated Segment Test (FAST). Our results show that the occam-pi program is much shorter, is easier to adapt and has a competitive performance when compared to versions programmed in the native programming model of P2012 and in OpenCL.

  • 141.
    Ghassemi, Fatemeh
    et al.
    University of Tehran, Tehran, Iran.
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Product Line Process Theory2016In: The Journal of logical and algebraic methods in programming, ISSN 2352-2208, E-ISSN 2352-2216, Vol. 85, no 1, part 2, p. 200-226Article in journal (Refereed)
    Abstract [en]

    Software product lines (SPLs) facilitate reuse and customization in software development by genuinely addressing the concept of variability. Product Line Calculus of Communicating Systems (PL-CCS) is a process calculus for behavioral modeling of SPLs, in which variability can be explicitly modeled by a binary variant operator. In this paper, we study different notions of behavioral equivalence for PL-CCS, based on Park and Milner's strong bisimilarity. These notions enable reasoning about the behavior of SPLs at different levels of abstraction. We study the compositionality property of these notions and the mutual relationship among them. We further show how the strengths of these notions can be consolidated in an equational reasoning method. Finally, we designate the notions of behavioral equivalence that are characterized by the property specification language for PL-CCS, called multi-valued modal μ-calculus. © 2015 The Authors. Published by Elsevier Inc.

  • 142.
    Girs, Svetlana
    et al.
    Mälardalen University, Västerås, Sweden.
    Uhlemann, Elisabeth
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Mälardalen University, Västerås, Sweden.
    Björkman, Mats
    Mälardalen University, Västerås, Sweden.
    Increased reliability or reduced delay in wireless industrial networks using relaying and Luby codes2013In: ETFA 2013: Proceedings of 2013 IEEE 18th International Conference on Emerging Techologies & Factory Automation : September 10-13, 2013, Cagliari, Italy, Piscataway, NJ: IEEE Press, 2013, article id 6648015Conference paper (Refereed)
    Abstract [en]

    Providing reliable and timely communication in wireless industrial networks is crucial. Previous research has shown that relaying can aid in achieving this goal. We consider the case when relay resources are sparse such that each relay needs to aid e.g., three different sensor nodes and propose to combine relaying with Luby codes. We let the relay node construct a Luby coded packet using the three source packets as input. The destination can then use the Luby coded packet to recover an erroneous or lost source packet regardless of which source that packet belonged to. The performance evaluation shows that our proposed scheme significantly increases the number of correctly received packets before the corresponding deadlines, or alternatively that high reliability can be maintained even if fewer time slots are allocated for retransmissions, thus lowering the delay. © 2013 IEEE.

  • 143.
    Girs, Svetlana
    et al.
    Mälardalen University, Västerås, Sweden .
    Willig, Andreas
    University of Canterbury, New Zealand .
    Uhlemann, Elisabeth
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Björkman, Mats
    Mälardalen University, Västerås, Sweden .
    On the role of feedback for industrial wireless networks using relaying and packet aggregation2014In: Proceedings of the IEEE International Conference on Industrial Technology, Piscataway, N.J.: IEEE Press, 2014, p. 743-748Conference paper (Refereed)
    Abstract [en]

    To be accepted for use in industrial applications, wireless technologies must offer similar performance in terms of reliability and timeliness as provided by current wired solutions. Wireless channels, introducing time-varying packet error rates, impose a significant challenge to fulfill these requirements. One way to improve reliability in industrial wireless networks is to use relaying, whereas packet aggregation is a method that can reduce delay. Hence, in this paper, we propose to use a combination of relaying and packet aggregation. Based on the type of feedback provided by the controller, the relay node can choose the most suitable way to use its allocated time slots such that more packets can reach the controller before their deadlines. The results show that allowing this kind of flexibility at the relay node results in performance improvements. The more flexibility, the greater the gain, and thus further improvements can be made by adjusting the schedule to take different types of feedback into account. @ IEEE 2015

  • 144.
    Girs, Svetlana
    et al.
    Mälardalen University, Västerås, Sweden.
    Willig, Andreas
    University of Canterbury, Christchurch, New Zealand.
    Uhlemann, Elisabeth
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Mälardalen University, Västerås, Sweden.
    Björkman, Mats
    Mälardalen University, Västerås, Sweden.
    Scheduling Transmissions in Industrial Networks Using Source Relaying and Packet Aggregation2015In: 2015 IEEE World Conference on Factory Communication Systems (WFCS), Piscataway, NJ: IEEE, 2015, p. 1855-1864, article id 7160565Conference paper (Refereed)
    Abstract [en]

    Wireless networks present a promising alternative to the currently used wired systems as they are more flexible, easier to install and maintain. However, requirements on reliability and timeliness which at present are met by wired networks, also need be fulfilled by wireless solutions. Relaying and packet aggregation have been recognised as viable tools to do this. However, introducing additional relay nodes into an industrial network is costly. Hence, in this paper we propose to use a combination of relaying and packet aggregation performed by the source nodes themselves. The results show that our proposal improves performance considerably, but also that the transmission schedule plays a crucial role. A schedule adapting to the varying channel conditions, improves the performance substantially. By carefully choosing which packet to aggregate, even further improvements can be achieved. © 2015 IEEE.

  • 145.
    Grahl, Daniel
    et al.
    Karlsruhe Institute of Technology, Karlsruhe, Germany.
    Bubel, Richard
    Technische Universität Darmstadt, Darmstadt, Germany.
    Mostowski, Wojciech
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Schmitt, Peter H.
    Karlsruhe Institute of Technology, Karlsruhe, Germany.
    Ulbrich, Mattias
    Karlsruhe Institute of Technology, Karlsruhe, Germany.
    Weiß, Benjamin
    Karlsruhe Institute of Technology, Karlsruhe, Germany.
    Modular Specification and Verification2016In: Deductive Software Verification – The KeY Book: From Theory to Practice / [ed] Wolfgang Ahrendt, Bernhard Beckert, Richard Bubel, Reiner Hähnle, Peter H. Schmitt & Mattias Ulbrich, Heidelberg: Springer, 2016, p. 289-351Chapter in book (Other academic)
    Abstract [en]

    In this chapter, concepts already addressed in previous chapters are reconsidered and extended to cater for modularity. In particular, it is shown how method contracts can be used in proofs (as opposed to being verified themselves). Another central topic is nonfunctional framing information, i.e., information on what locations a method may write to or read from. But, there are also items that are discussed here in depth for the first time: model methods, an abstraction of Java methods that are only used in specification, verification of recursive methods, and object invariants. For any of the arising proof obligations the calculus rules needed to dispatch them are shown. © Springer International Publishing AG 2016.

  • 146.
    Groote, Jan Friso
    et al.
    Eindhoven University of Technology, Eindhoven, The Netherlands.
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Book Announcement: Modeling and Analysis of Communicating Systems2014In: Bulletin of the European Association for Theoretical Computer Science, ISSN 0252-9742, no 114Article, book review (Other academic)
  • 147.
    Groote, Jan Friso
    et al.
    Eindhoven University of Technology, Eindhoven, The Netherlands.
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Modeling and Analysis of Communicating Systems2014Book (Refereed)
  • 148.
    Hafemann Fragal, Vanderson
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Automatic generation of configurable test-suites for software product lines2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Software Product Line Engineering (SPLE) is an approach used in the development of similar products, which aims at systematic reuse of software artifacts. The SPLE process has several activities executed to assure software quality. Quality assurance is of vital importance for achieving and maintaining a high quality for various artifacts, such as products and processes. Testing activities are widely used in industry for quality assurance. However, the effort for applying testing is usually high, and increasing the testing efficiency is a major concern. A common means of increasing efficiency is automation of test design. Several techniques, processes, and strategies were developed for SPLE testing, but still many problems are open in this area of research. The challenge in focus is the reduction of the overall test effort required to test SPLE products. Test effort can be reduced by maximizing test reuse using models that take advantage of the similarity between products. The thesis goal is to automate the generation of small test-suites with high fault detection and low test redundancy between products. To achieve the goal, equivalent tests are identified for a set of products using complete and configurable test-suites. Two research directions are explored, one is product-based centered, and the other is product line-centered. For test design, test-suites that have full fault coverage were generated from state machines with and without feature constraints. A prototype tool was implemented for test design automation. In addition, the proposed approach was evaluated using examples, experimental studies, and an industrial case study for the automotive domain. The results of the product-based centered approach indicate a reduction of 36% on the number of test cases that need to be concretized. The results of the product line-centered approach indicate a reduction of 50% on the number of test cases generated for groups of product configurations.

  • 149.
    Hajiaghayi, Mohammad Taghi
    et al.
    University of Maryland, College Park, MD, USA.
    Mousavi, Mohammad RezaHalmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Topics in Theoretical Computer Science: The First IFIP WG 1.8 International Conference, TTCS 2015, Tehran, Iran, August 26-28, 2015, Revised Selected Papers2016Conference proceedings (editor) (Refereed)
  • 150. Hassan, Aamir
    et al.
    Larsson, Tony
    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).
    On the requirements on models and simulator design for integrated VANET Simulation2011Conference paper (Refereed)
    Abstract [en]

    Wireless communication can reduce risks for collision between vehicles by the exchange of kinematic data. Vehicular safety applications based on such information sharing must be tested before it is deployed in real world. For this purpose simulation is a valuable complement to expensive outdoor experiments. Analysis of VANET applications requires that both a vehicle motion and a data network simulator can be used at the same time, feeding simulation data to each other. Tools exist for this purpose but most of them have problem with their integration. This article discusses how to simulate vehicular networks influenced by micro level vehicle motion and macro level traffic flow pattern models to analyze its effect on wireless communication. We discus the shortcomings of current VANET simulators and then provide recommendations for how to perform useful VANET simulations.

1234567 101 - 150 of 459
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf