| 1. |
- Bergenhem, Carl, et al.
(författare)
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Heterogeneous real-time services in high-performance system area networks - application demands and case study definitions
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- To be able to verify the feasibility of high-performance networks, it is essential to evaluate them according to specific application requirements. At the same time, specifications of quite general, or understandable, application requirements are needed for the ability to make repeated analyses on different networks. Especially, heterogeneous real-time requirements must be defined to be able to analyze networks to be used in future applications. In this report, we introduce two application fields where system area networks (SANs) supporting heterogeneous real-time services are highly desirable if not required: radar signal processing and large IP routers. For each application field, a case study with heterogeneous real-time communication requirements is defined. No case studies are presented in this report. Instead, they are defined for later evaluations to determine how suitable networks are for applications with heterogeneous real-time communication requirements.
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| 2. |
- Forsberg, Håkan, et al.
(författare)
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Radar signal processing using pipelined optical hypercube interconnects
- 2001
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Ingår i: Proceedings of the 15th International Parallel and Distributed Processing Symposium. - Los Alamitos, California : IEEE Computer Society Press. - 0769509908 ; , s. 2043-2052
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Konferensbidrag (refereegranskat)abstract
- In this paper, we consider the mapping of two radar algorithms on a new scalable hardware architecture. The architecture consists of several computational modules that work independently and send data simultaneously in order to achieve high throughput. Each computational module is composed of multiple processors connected in a hypercube topology to meet scalability and high bisection bandwidth requirements. Free-space optical interconnects and planar packaging technology make it possible to transform the hypercubes into planes. Optical fan-out reduces the number of optical transmitters and thus the hardware cost. Two example systems are analyzed and mapped onto the architecture. One 64-channel airborne radar system with a sustained computational load of more than 1.6 TFLOPS, and one ground-based 128-channel radar system with extreme inter-processor communication demands.
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| 3. |
- Fröberg, Andreas, 1985, et al.
(författare)
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Effects of an Empowerment-Based Health-Promotion School Intervention on Physical Activity and Sedentary Time among Adolescents in a Multicultural Area
- 2018
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Ingår i: International Journal of Environmental Research and Public Health. - Basel : MDPI. - 1661-7827 .- 1660-4601. ; 15:11
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Tidskriftsartikel (refereegranskat)abstract
- Physical activity (PA) decreases with age, and interventions are needed to promote PA during adolescence, especially, among those in low-socioeconomic status (SES) areas. The aim of this study was to investigate whether a two-year, empowerment-based health-promotion school intervention had any effects on changes in (a) moderate-to-vigorous PA (MVPA), (b) sedentary time (SED), (c) exercise training (ET) frequency, and (d) ET duration, among adolescents. Participants (aged 12-13 years at baseline) from one intervention school and two control schools, were recruited from a multicultural area of Sweden, characterized by low-SES. During the course of the two-year intervention, a total of 135 participants (43% boys) were included in the study. The intervention was developed and implemented as a result of cooperation and shared decision-making among the researchers and the participants. MVPA and SED were measured with accelerometers, and ET frequency and duration was self-reported at the beginning of the seventh, eighth, and ninth grade, respectively. There were no significant effects of the two-year, empowerment-based health-promotion school intervention on changes in the accelerometer-measured MVPA and SED, or the self-reported ET frequency and duration, among the adolescents. Overall, the intervention was unsuccessful at promoting PA and reducing SED. Several possible explanations for the intervention's lack of effects are discussed.
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| 4. |
- Hoang, Hoai, et al.
(författare)
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Deadline first scheduling in switched real-time Ethernet - deadline partitioning issues and software implementation experiments
- 2002
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Ingår i: Euromicro RTS 2002. - Los Alamitos, Calif. : IEEE Computer Society. - 0769516653 - 9780769516653 - 076951667X - 9780769516677 ; , s. 68-71
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Konferensbidrag (refereegranskat)abstract
- This paper presents work on a switched Ethernet network extended to allow for earliest deadline first (EDF) scheduling. We show by example that asymmetric deadline partitioning between the links of a real-time channel can increase the utilization substantially, still not violating the real-time guarantees. We also report measurements on a software implementation of the switch on an ordinary PC.
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| 5. |
- Hoang, Hoai, et al.
(författare)
-
Switched real-time Ethernet with earliest deadline first scheduling - protocols and traffic handling
- 2002
-
Ingår i: Proceedings. - Los Alamitos, Calif. : IEEE Computer Society. - 0769515738 - 9780769515731 - 0769515746 - 9780769515748 - 0769515754 - 9780769515755 ; 5:1, s. 105-115
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Konferensbidrag (refereegranskat)abstract
- There is a strong interest of using the cheap and simple Ethernet technology for industrial and embedded systems. This far, however, the lack of real-time services has prevented this change of used network technology. This paper presents enhancements to full-duplex switched Ethernet for the ability of giving throughput and delay guarantees. The switch and the end-nodes controls the real-time traffic with Earliest Deadline First (EDF) scheduling on the frame level. No modification to the Ethernet standard is needed in the network that supports both real-time and non-real-time TCP/IP communication. The switch is responsible for admission control where feasibility analysis is made for each link between source and destination. The switch broadcasts Ethernet frames regularly to clock synchronize the end nodes and to implement flow control for non-real-time traffic.
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| 6. |
- Jonsson, Magnus, 1969-, et al.
(författare)
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Analysing AFDX Networks Using End-to-end Response Time Analysis
- 2015
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Ingår i: Journal of Interconnection Networks. - Singapore : World Scientific. - 0219-2659 .- 1793-6713. ; 14:4
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a novel real-time analysis framework for AFDX (Avionics Full Duplex Switched Ethernet) networks. The framework, based on end-to-end response time analysis, calculates not only delay bounds, but also the maximum jitter for each VL (Virtual Link) at each hop, which is necessary according to the AFDX standard. Moreover, the framework supports multicasting, i.e., VLs with several paths, and VLs with arbitrary delay bounds, i.e., shorter, longer, or equal to their periods. An analysis method to calculate the worst-case buffer population is included in the framework, as it is important to guarantee that no buffer-overflow occurs. With a performance surpassing that of Network Calculus and comparable with Trajectory Approach, our framework presents a good choice due to its many features and its foundation in well-accepted analysis methods.
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| 7. |
- Jonsson, Magnus, 1969-, et al.
(författare)
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Fiber-ribbon pipeline ring network for high-performance distributed computing systems
- 1997
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Ingår i: Proceedings of the Third International Symposium on Parallel Architectures, Algorithms, and Networks, 1997. (I-SPAN '97). - : IEEE. ; , s. 138-143
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Konferensbidrag (refereegranskat)abstract
- In this paper, we propose a high-bandwidth ring network built up with fiber-ribbon point-to-point links. The network has support for both packet switched and circuit switched traffic. Very high throughputs can be achieved in the network due to pipelining, i.e., several packets can be traveling through the network simultaneously but in different segments of the ring. The network can be built today using fiber-optic off-the-shelf components. The increasingly good price/performance ratio for fiber-ribbon links indicates a great success potential for the proposed kind of networks. We also present a massively parallel radar signal processing system with exceptionally high demands on the communication network. An aggregated throughput of tens of Gb/s is needed in this application, and this is achieved with the proposed network.
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| 8. |
- Jonsson, Magnus, 1969-, et al.
(författare)
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Time-deterministic WDM star network for massively parallel computing in radar systems
- 1996
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Ingår i: Proceedings of the Third International Conference on Massively Parallel Processing Using Optical Interconnections. - Los Alamitos, California : IEEE Computer Society Press. - 0818675918 ; , s. 85-93
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Konferensbidrag (refereegranskat)abstract
- In massively parallel computer systems for embedded real-time applications there are normally very high bandwidth demands on the interconnection network. Other important properties are time-deterministic latency and services to guarantee that deadlines are met. In this paper we analyze how these properties vary with the design parameters for a passive optical star network, specifically when used in a massively parallel radar signal processing system. The aggregated bandwidth and computational power of the radar system are approximately 45 Gb/s and 100 GOPS, respectively. The analysis is focused on the medium access control protocol, called TD-TWDMA, for the time and wavelength multiplexed network. It is concluded that the proposed network is very well suited to this kind of signal-processing applications. We also present a new distributed slot-allocation algorithm with real-time properties.
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| 9. |
- Mors, Niklas, et al.
(författare)
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A Ethernet based Metropolitan Area Open Access Architecture
- 2003
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Ingår i: IASTED International Multi-Conference on Applied Informatics. - : IASTED/ACTA Press. - 0889863415 ; , s. 571-576
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Konferensbidrag (populärvet., debatt m.m.)abstract
- Quality of Service (QoS) has become increasingly important in metropolitan area networks and even more important in open access networks where service providers should be able to offer their services on equal terms. This paper present a network architecture with a hierarchical star-mesh topology, which provides the scalability and redundancy required for future open access networks. To support QoS a combination of Ethernet and Multiprotocol Label Switching (MPLS) is proposed. With the use of a switch, on the highest level, based on micro electromechanical system (MEMS) technology this proposed architecture could reach aggregated bitrates above 10 Tbit/s. IPSec is proposed for solving the security issues in the network that emerges when different service providers share the same network and future applications are developed.
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| 10. |
- Pelliccione, Patrizio, 1975, et al.
(författare)
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Architecting cars as constituents of a system of systems
- 2016
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Ingår i: ACM International Conference Proceeding Series. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450363990 ; , s. 1-7
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Konferensbidrag (refereegranskat)abstract
- Future transportation systems will be a heterogeneous mix of items with varying connectivity and interoperability. A mix of new technologies and legacy systems will co-exist to realize a variety of scenarios involving not only connected cars but also road infrastructures, pedestrians, cyclists, etc. Future transportation systems can be seen as a System of Systems (SoS), where each constituent system - one of the units that compose an SoS - can act as a standalone system, but the cooperation among the constituent systems enables new emerging and promising scenarios. In this paper we investigate how to architect cars so that they can be constituents of future transportation systems. This work is realized in the context of two Swedish projects coordinated by Volvo Cars and involving some universities and research centers in Sweden and many suppliers of the OEM, including Autoliv, Arccore, Combitech, Cybercom, Knowit, Prevas, ÅF-Technology, Semcom, and Qamcom.
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