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  • 1.
    Boklund, Andreas
    et al.
    University West, Department of Technology, Mathematics and Computer Science, Division for Computer Science.
    Jiresjö, Christian
    University West, Department of Technology, Mathematics and Computer Science, Division for Computer Science.
    Mankefors, Stefan
    University West, Department of Technology, Mathematics and Computer Science, Division for Computer Science.
    The Story Behind Midnight, a Part Time High Performance Cluster2003In: International conference on Parallel and Distributed Processing Techniques and Applications / [ed] Hamid R. Arabnia, Las Vegas: CSREA Press , 2003, p. 173-178Conference paper (Other academic)
    Abstract [en]

    In this paper, we present the creation process andthe purpose behind the Midnight cluster. It isdisguised as a computer laboratory during the day,but turns into a high performance compute clusterduring the night.The main focus of this paper is on the basic issueswith creating a part time compute cluster. TheMidnight cluster was constructed to serve both as aCPU harvester and as a platform for further studies.The main goal of our upcoming research is toev aluate different methods for handling shapechangeand process management on the cluster, andhow these factors affect running processes, stabilityand performance.

  • 2.
    de Blanche, Andreas
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Lundqvist, Thomas
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Terrible Twins: A Simple Scheme to Avoid Bad Co-Schedule2016In: Proceedings of the 1st COSH Workshop on Co-Scheduling of HPC Applications / [ed] Trinitis, Carsten ; Weidendorfer, Josef, Munchen, 2016, Vol. 1, p. 1-6Conference paper (Refereed)
    Abstract [en]

    Co-scheduling processes on different cores in the same server might lead to excessive slowdowns if they use a shared resource,like the memory bus. If possible, processes with a high shared resource use should be allocated to different server nodes to avoid contention, thus avoiding slowdown.This paper introduces the simple scheme of avoiding to coschedule twins, i.e., several instances of the same program.The rational for this is that instances of the same program use the same resources and they are more likely to be either low or high resource users − high resource users should obviously not be combined, but a bit non-intuitively, it is also shown that low resource users should also not be combined in order to not miss out on better scheduling opportunities.This is verified using both a statistical argument as well as experimentally using ten programs from the NAS parallel benchmark suite. By using the simple rule of forbidding twins, the average slowdown is shown to decrease from 6.6% down to 5.9%, and the worst case slowdown is lowered from 12.7% to 9.0%, indicating a considerable improvement despite having no information about any programs' resource usage or slowdown behavior.

  • 3.
    de Blanche, Andreas
    et al.
    University West, School of Business, Economics and IT, Division of Computer Science and Informatics.
    Mankefors-Christiernin, Stefan
    University West, School of Business, Economics and IT, Division of Computer Science and Informatics.
    Method for Experimental Measurement of an Applications Memory Bus Usage2010In:   / [ed] Hamid Arabnia, CSREA Press , 2010Conference paper (Refereed)
    Abstract [en]

    The disproportion between processor and memory bus capacities has increased constantly during the last decades. With the introduction of multi-core processors the memory bus capacity is divided between the simultaneously executing processes (cores). The memory bus capacity directly affects the number of applications that can be executed simultaneously at its full potential. Thus, against this backdrop it becomes important to estimate how the limitation of the memory bus effects the applications performance. Towards this end we introduce a method and a tool for experimental estimation of an applications memory requirement as well as the impact of sharing the memory bus has on the execution times. The tool enables black-box approximate profiling of an applications memory bus usage during execution. It executes entirely in user-space and does not require access to the application code, only the binary. 

  • 4.
    de Blanche, Andreas
    et al.
    University West, School of Business, Economics and IT, Division of Computer Science and Informatics.
    Mankefors-Christiernin, Stefan
    University West, School of Business, Economics and IT, Division of Computer Science and Informatics.
    Minimizing Total Cost ($$) and Maximizing Throughput: A Metric for Node versus Core Usage in Multi-Core Clusters2010In: Proceedings of the International conference on Parallel and Distributed Processing Techniques and Applications:   / [ed] Hamid R. Arabnia, Las Vegas: CSREA Press , 2010, p. 241-248Conference paper (Refereed)
    Abstract [en]

    When most commercial clusters had one processor core each, decreasing the runtime meant executing the application over more nodes – the associated cost (in $) would scale linearly with the number of nodes. However with the recent advances of multi-core processors the execution time can be increased by utilizing more nodes or by utilizing more cores in the same nodes. In the industrial cluster environments a key question is how to run the applications, to minimize the total cost while maximizing the throughput and solution times of the individual jobs. The number of core used and their contribution to the total runtime reduction is especially interesting since companies often use commercial software that is licensed per year and process. The annual license cost of one single process is often far greater than that of a complete cluster node including maintenance and power. In this paper we present a metric for the calculation of the optimal way to run an application on a cluster consisting of multi-core nodes in order to minimize the cost of executing the said job. 

  • 5.
    de Blanche, Andreas
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Namaki, Nima
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Mankefors-Christiernin, Stefan
    University West, School of Business, Economics and IT, Division of Computer Engineering.
    Multicore Clusters for CFD Simulations: Comparative Study of Three CFD-Softwares2012In: PROCEEDINGS OFTHE 2012 INTERNATIONAL CONFERENCE ONPARALLEL AND DISTRIBUTED PROCESSING TECHNIQUES ANDAPPLICATIONS, PART II / [ed] Hamid R. Arabnia, Hiroshi Ishii, Minoru Ito Kazuki Joe, Hiroaki Nishikawa, CSREA Press, 2012, p. 855-852Conference paper (Refereed)
    Abstract [en]

    Multicore processors have come to stay, fulfill Moore’s law and might very well revolutionize the computer industry. However, we are now in a transitional period before the new programming models, numerical algorithms and general computer architecture have been developed and the software has been rewritten. This paper focuses on the effects multicore based systems have on industrial computational fluid dynamics (CFD) simulations. The most significant finding was that five of the models ran faster when only one process was executed on each multicore node instead of two. In these cases the execution time was increased by between 6.5% and 64% with a median increase of 10% when utilizing both cores.

  • 6.
    Gunnarsson, Alexander
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Från rutnätszoom till genetisk algoritm vid optimering av dyra funktioner2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    D. Lindström has developed an algorithm for optimization of expensive functions which is based on response surface methodology which means that a model of the expensive function is created. To optimize the response surface the algorithm is making use of a grid zoom. This grid zoom is replaced by a genetic algorithm which is based on biological evolution. Measurements are done before and after the modification focusing on CPU time. A vectorization of the code is also performed.

    Expensive functions often appear in the real world. An expensive function could be to run a simulation with certain settings to see how good they are. Because the simulation takes a long time to run you can't just try everything but instead need to strategically select which parameters to test. This it what Lindströms algorithm does.

    The results show that the grid zoom was more effective than expected but that it is ineffective in higher dimensions.

  • 7.
    Gustafsson, Johan
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Kanefur, Johan
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Influens av sensorteknik inom styrketräning2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vi vill börja med att tacka vår handledare Dena Ala-Hussain för all hjälp och guidning vi har fått genom arbetets gång.

    Vi vill även tacka STC Kungälv Rollsbo och alla personer som medverkade i testandet av sensorsystemet.

    Fördelningen av arbetsuppgifter har varit jämn och båda har deltagit i alla moment.

  • 8.
    Hadi, Yasir
    et al.
    University West, Department of Economics and IT, Division of Computer Engineering.
    Wisniewski, Damian
    University West, Department of Economics and IT, Division of Computer Engineering.
    Proposal and evaluation of a smart post box system2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Our thesis work is focusing on usage of wireless technologies in post delivery systems. The technologies that we will investigate are RFID and NFC, we want to present the advantages and disadvantages of both technologies in this development process. We will do that, because of cost measures for the end users. This paper will not include prices for devices and assembling due to huge amount of possibilities. Work will be based on the statistic of the question if the customers want to have NFC based post boxes and those functions that will be available to customers to make it easier and more comfortable to use smart post boxes and which security issues they may cause.

    To promote new technology that will replace an already used one, we will need to convince customers that the change will be worth of making. We will also spend time to figure out how it would be best to make it work for both customers and post companies. We will prove why were most suitable to manage post boxes.

    This document contains information about users' needs and their expectations from the company who would develop it. Surveys that are included in this project are showing clear view to customers requirement. Futhermore this report includes system vision and design how system can be created.

  • 9.
    Johansson, Joakim
    University West, Department of Economics and IT.
    Avståndsvarnare till Mobiltelefon2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes a study, description and testing of parts to an application adapted to the operating system Android. The application is supposed to measure the distance to a car ahead. Apart from distance measurements the ability of the application to calculate its own speed with the help of GPS is tested. From these two parameters, speed, distance and some constants the theoretical stopping distance of the car will be calculated in order to warn the driver if the car is too close to the car ahead in relation to its own speed and stopping distance.

    Tests were conducted on the different applications that were programmed and the result showed that the camera technique in the mobile phone itself limits the maximum distance of the distance measurement application. The max distance the tests in this thesis revealed was approximately 5 meters. The measurement done to the GPS speed calculating application showed that the application was more accurate than the speedometer in the test car.

    The result of this thesis was that if all the parts were to be put together to a single application the maximum speed that it could be used with some functionality was 13,8 kilometers/hour assuming that the car ahead is at a standstill and the camera on the mobile phone is in a straight line from the license plate.

  • 10.
    Lundmark, Elias
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Persson, Chris
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Prestandaanalys av VoIP-trafik över IPsec2016Independent thesis Basic level (degree of Bachelor), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    Voice over IP (VoIP) is a time sensitive type of data, where high latency results in unusable phone calls. The goal is to keep the latency down while new features are desired, such as security as prevention against monitoring. Internet Protocol Security (IPsec) is a protocol suite used for securing data traffic through a tunnel - without the end users awareness. A problem that may occur when IPsec is encrypting data, delay will be added which is not a favourable condition for VoIP. When encryption algorithms become more complex, they become more secure, but with the cost of longer encryption and decryption times which in turn may have a negative effect on real-time applications.This report examines IPsec, cryptography, VoIP and the relationship between them. The measurement shows which encryption algorithm that is most effective in conjunction with encryption of VoIP. The results show which encryption algorithms that may be used without affecting the quality of a VoIP call in a controlled lab environment.

  • 11.
    Lundmark, Elias
    et al.
    University West, Department of Engineering Science.
    Persson, Chris
    University West, Department of Engineering Science.
    de Blanche, Andreas
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Lundqvist, Thomas
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Increasing Throughput of Multiprogram HPC Workloads: Evaluating a SMT Co-Scheduling Approach2017Conference paper (Refereed)
    Abstract [en]

    Simultaneous Multithreading (SMT) is a technique that allows formore efficient processor utilization by scheduling multiple threadson a single physical core. Previous research have shown an averagethroughput increase of around 20% with an SMT level of two, e.g.two threads per core. However, a bad combination of threads canactually result in decreased performance. To be conservative, manyHPC-systems have SMT disabled, thus, limiting the number ofscheduling slots in the system to one per core. However, for SMT tonot hurt performance, we need to determine which threads shouldshare a core. In this poster, we use 30 random SPEC CPU job mixedon a twelve-core Broadwell based node, to study the impact ofenabling SMT using two different co-scheduling strategies. Theresults show that SMT can increase performance especially whenusing no-same-program co-scheduling.

  • 12.
    Mark, Emil
    University West, Department of Engineering Science.
    Usability: Through the use of guidelines and user participation2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Department of Engineering Science at University West in Trollhättan was in need of a new system for scheduling personnel, as the existing system is based upon an Excel-file and is hard to work with and does not provide an easy way for the users to collaborate.The purpose of this study was to examine how existing principles and guidelines regarding interface design can be used to create a new web based system with a high usability. The purpose is also to examine how participatory design affects the design process and outcome.To create a system with a high grade of usability, a number of existing rules and guidelines regarding usability and a number of subjects regarding interaction design, were used by the development team as tools.Even though the study showed that usability guidelines can be a valuable tool and provide a good foundation it is important to emphasize the use of other techniques. For example the use of participatory design, which in the study was found to be of great value to the development team.

  • 13.
    Namaki, Nima
    et al.
    University West, School of Business, Economics and IT, Division of Computer Engineering.
    de Blanche, Andreas
    University West, School of Business, Economics and IT, Division of Computer Engineering.
    Mankefors-Christiernin, Stefan
    University West, School of Business, Economics and IT, Division of Computer Engineering.
    Exhausted Dominated Performance: Basic Proof of Concept2010In: International conference on Parallel and Distributed Processing Techniques and Applications / [ed] Hamid R. Arabnia, Las Vegas: CSREA , 2010, p. 63-67Conference paper (Refereed)
  • 14.
    Riddarlo, Niklas
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Tirén, Dan
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Software Defined Networks: Test av kontrollenheter med Openflow i lager 2full-mesh2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Software Defined Networks (SDN) is a concept that separates the control plane from data plane in network devices. The control plane moves to a central controller. The purpose of the controller is to communicate and dictate how the network devices should forward the traffic. One of the protocols that controllers use to communicate with the network devices is OpenFlow.

    The purpose of the thesis is to examine how different SDN-controllers utilize links in a full-mesh topology, how they handle broadcast traffic and the problem with loops. The advantage of a full-mesh topology is that network devices are able to reach each other with just one hop and provides maximum protection against failing devices and links. A problem with redundant links is the risk of broadcast storms and loops.

    The controllers have been exposed to four different scenarios. How they handle broadcast traffic and how they use redundant links to forward traffic. If they are enable to load balance and redirect active flows if the link fails.

    The controllers used in the tests are: Floodlight, POX and OpenDaylight. They were connected to a virtual network generated by the network emulator Mininet.

    Floodlight and POX both utilized the links in full-mesh topology better than STP would in a traditional network. No links were blocked from forwarding traffic without any broadcast storms happening. OpenDaylight were unable to handle our full-mesh topology which led to a broadcast storm. Floodlight and POX couldn’t redirect active flows when the link went down

  • 15.
    Thelander, Tomas
    University West, Department of Economics and IT.
    Alternatives to Native Mobile Development2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study looks at alternatives to creating applications for the common mobile operating systems using their respective native languages. Many proposals on how to bridge the differences of the platforms exist, with Applecerator Titanium being one of them, offering native applications for several platforms with one common code. Titanium development is here compared to standard Android development by creating identical applications using the two technologies and comparing the development processes. Titanium shows great promise and is able to perform the same operations as Java, with significantly less code required. The Titanium application also works on other platforms, but with some additional work required. The application created with Titanium does not match standard Android development when developing for a single platform. However, when developing for multiple platforms it may be a suitable alternative, at least when developing applications without advanced functionality

  • 16.
    Ulasi, Micheal
    University West, Department of Economics and IT, Division of Computer Engineering.
    IP surveillance comparison between a Banana Pi camera system and a Raspberry Pi B+ camera system2015Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    This report discusses the implementation of IP surveillance technology using a decentralized architecture. The research focuses on the comparison between a Banana Pi camera system and a Raspberry Pi B+ camera system. This implies testing both systems as decentralized camera system. Both Pi camera systems, are running Raspbian OS and on them a CSI camera module is attached, and use their VLC media player application that is configured with HTTP/RTSP protocol to send video streams to clients on the LAN. The configuration uses either CIF and 1080P video resolution with motion and without motion respectively, at different intervals in the experiment.

    Information obtained from the research analyzes, revealed that the Raspberry Pi B+ is most suitable as a decentralized camera system than the Banana Pi is. It was possible for the Banana Pi to stream video using HTTP protocol and 1080P resolution with motion and without motion, but it could not use RSTP protocol and CIF resolution. Furthermore, the system crashed whenever the number of remote video streams on the Banana Pi were above than one connection. Although, during this one connection, the CPU usage was 100% and the memory usage was above 200MB. The bandwidth consumption was low, and the video quality was acceptable.The Raspberry Pie B+, processed most remote video streams and had most acceptable video qualities during the use of CIF resolution with motion and without motion, in contrast with use of 1080P with motion and without motion.

    Results also indicated that the Raspberry Pi B+ performed best with the use of CIF without motion, because it served all 50 remote video streams with 33.5% CPU usage. The Raspberry Pi B+, demonstrated poor performance during the 1080P with motion because it served just five remote video streams with 28.8% CPU usage. In overall, the bandwidth and memory usage increased simultaneously on the Raspberry Pi B+ as the number of remote video streams it served increased.

1 - 16 of 16
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