| 1. |
- Andersson, H. Robert H., et al.
(författare)
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Flipping the Data Center Network : Increasing East-West Capacity Using Existing Hardware
- 2017
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Ingår i: 2017 IEEE 42nd Conference on Local Computer Networks (LCN), 9-12 Oct. 2017. - : IEEE. - 9781509065233 - 9781509065226 ; , s. 211-214
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Konferensbidrag (refereegranskat)abstract
- In today's datacenters, there is an increasing demand for more network traffic capacity. The majority of the increase in traffic is internal to the datacenter, i.e., it flows between different servers within the datacenter. This category of traffic is often referred to as east-west traffic and traditional hierarchical architectures are not well equipped to handle this type of traffic. Instead, they are better suited for the north-southbound traffic between hosts and the Internet. One suggested solution for this capacity problem is to adopt a folded CLOS topology, also known as spine-leaf, which often relies on software defined network (SDN) controllers to manage traffic. This paper shows that it is possible to implement a spine-leaf network using commodity-ofthe-shelf switches and thus improve the east-west traffic capacity. This can be obtained using low complexity configuration and edgerouting for load balancing, eliminating the need for a centralized SDN controller.
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| 2. |
- de Blanche, Andreas, 1975-, et al.
(författare)
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Addressing characterization methods for memory contention aware co-scheduling
- 2015
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Ingår i: Journal of Supercomputing. - : Springer Science and Business Media LLC. - 0920-8542 .- 1573-0484. ; 71:4, s. 1451-1483
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Tidskriftsartikel (refereegranskat)abstract
- The ability to precisely predict how memory contention degrades performance when co-scheduling programs is critical for reaching high performance levels in cluster, grid and cloud environments. In this paper we present an overview and compare the performance of state-of-the-art characterization methods for memory aware (co-)scheduling. We evaluate the prediction accuracy and co-scheduling performance of four methods: one slowdown-based, two cache-contention based and one based on memory bandwidth usage. Both our regression analysis and scheduling simulations find that the slowdown based method, represented by Memgen, performs better than the other methods. The linear correlation coefficient (Formula presented.) of Memgen's prediction is 0.890. Memgen's preferred schedules reached 99.53 % of the obtainable performance on average. Also, the memory bandwidth usage method performed almost as well as the slowdown based method. Furthermore, while most prior work promote characterization based on cache miss rate we found it to be on par with random scheduling of programs and highly unreliable.
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| 3. |
- de Blanche, Andreas, 1975-, et al.
(författare)
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Node Sharing for Increased Throughput and Shorter Runtimes : an Industrial Co-Scheduling Case Study
- 2018
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Ingår i: Proceedings of the 3rd Workshop on Co-Scheduling of HPC Applications (COSH 2018). ; , s. 15-20
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Konferensbidrag (refereegranskat)abstract
- The allocation of jobs to nodes and cores in industrial clusters is often based on queue-system standard settings, guesses or perceived fairness between different users and projects. Unfortunately, hard empirical data is often lacking and jobs are scheduled and co-scheduled for no apparent reason. In this case-study, we evaluate the performance impact of co-scheduling jobs using three types of applications and an existing 450+ node cluster at a company doing large-scale parallel industrial simulations. We measure the speedup when co-scheduling two applications together, sharing two nodes, compared to running the applications on separate nodes. Our results and analyses show that by enabling co-scheduling we improve performance in the order of 20% both in throughput and in execution times, and improve the execution times even more if the cluster is running with low utilization. We also find that a simple reconfiguration of the number of threads used in one of the applications can lead to a performance increase of 35-48% showing that there is a potentially large performance increase to gain by changing current practice in industry.
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| 4. |
- Lundmark, Elias, et al.
(författare)
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Increasing Throughput of Multiprogram HPC Workloads : Evaluating a SMT Co-Scheduling Approach
- 2017
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 5. |
- Lundqvist, Lars-Olov, 1958-, et al.
(författare)
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Risk markers for not returning to work among people with acquired brain injury
- 2019
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Konferensbidrag (refereegranskat)abstract
- BACKGROUND: Research shows that variety of factors are related to risks of not returning to work among people with acquired brain injury (ABI). In Sweden, 40% of those with ABI in working age return to work within two years after the injury, which in line with international findings. However, since countries may differ in work rehabilitation, social security systems, culture and laws, different factors may influence the possibilities of returning to work across countries.AIMS: The aim of this study was to investigate person, injury, activity and rehabilitation related risk markers for not return to work among persons with ABI in Sweden.METHODS: Retrospective data of an ABI cohort of 2008 people from the WebRehab Sweden quality register were used.RESULTS: Analyses showed that the risk ratio for not returning to work was larger for people that, among the Personal factors, were woman, born outside of Sweden, had low education level, and not having children in the household; among the injury related factors, had long (> 2 months) hospital stay, aphasia, low motor function, low cognitive function, high pain/discomfort, and high anxiety/depression; among the activity related factors, had low function in self-care, inability to perform usual activities, and had their driver´s license suspended; and finally among the rehabilitation related factors, were satisfied with treatment and having influence over their rehabilitation plan.DISCUSSION / CONCLUSION: Several factors in different areas were risk markers for not returning to work among people with ABI. This suggest that work rehabilitation and interventions, in addition to direct injury related issues, need to address personal related, activity related and rehabilitation related factors in order to increase the patient´s possibility to return to work. Influences of general and country specific factors on returning to work among people with ABI will be discussed.
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| 6. |
- Lundqvist, Thomas, 1967-, et al.
(författare)
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Thing-to-thing electricity micro payments using blockchain technology
- 2017
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Ingår i: Global Internet of Things Summit (GIoTS), 2017. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781509058730 ; , s. 261-266
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Konferensbidrag (refereegranskat)abstract
- Thing-to-thing payments are a key enabler in the Internet of Things (IoT) era, to ubiquitously allow for devices to pay each other for services without any human interaction. Traditional credit card-based systems are not able to handle this new paradigm, however blockchain technology is a promising payment candidate in this context. The prominent example of blockchain technology is Bitcoin, with its decentralized structure and ease of account creation. This paper presents a proof-of-concept implementation of a smart cable that connects to a smart socket and without any human interaction pays for electricity. In this paper, we identify several obstacles for the widespread use of bitcoins in thing-to-thing payments. A critical problem is the high transaction fees in the Bitcoin network when doing micro transactions. To reduce this impact, we present a single-fee micro-payment protocol that aggregates multiple smaller payments incrementally into one larger transaction needing only one transaction fee. The proof-of concept shows that trustless, autonomous, and ubiquitous thing-to-thing micro-payments is no longer a future technology.
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| 7. |
- Matérne, Marie, 1967-, et al.
(författare)
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Change in quality of life in relation to returning to work after acquired brain injury : a population-based register study
- 2018
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Ingår i: Brain Injury. - : Taylor & Francis Group. - 0269-9052 .- 1362-301X. ; 32:13-14, s. 1731-1739
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: This study investigated changes in quality of life (QoL) in relation to return to work among patients with acquired brain injury (ABI).METHOD: The sample consisted of 1487 patients with ABI (63% men) aged 18-66 years (mean age 52) from the WebRehab Sweden national quality register database. Only patients who worked at least 50% at admission to hospital and were on full sick leave at discharge from hospital were included. QoL was measured by the EuroQol EQ-5D questionnaire.RESULTS: Patients who returned to work perceived a larger improvement in QoL from discharge to follow-up one year after injury compared to patients who had not returned to work. This difference remained after adjustment for other factors associated with improved QoL, such as having a university education, increased Extended Glasgow Outcome Scale scores and getting one's driving licence reinstated.CONCLUSION: Return to work is an important factor for change in QoL among patients with ABI, even after adjusting for other factors related to QoL. This is consistent with the hypothesis that having employment is meaningful, increases self-esteem and fosters participation in society. Thus, helping patients with ABI return to work has a positive influence on QoL.
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| 8. |
- Matérne, Marie, 1967-, et al.
(författare)
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Opportunities and barriers for successful return to work after acquired brain injury : A client perspective
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Research aimThe aim of this study was to increase our knowledge about the opportunities and barriers for successfully return to work (RTW) among individuals with acquired brain injury (ABI).MethodologyAdults who have ABI were interviewed in regard to their experiences of the work rehabilitation process. The informants (5 females, 5 males) had participated in a work rehabilitation, had successfully RTW and had worked at least 50 % in at least a year after the injury. The interviews were transcribed, structured and analyzed by latent content analysis with a hermeneutic approach.Findings and conclusionsThree main themes that influenced RTW after ABI were identified: (i) individually adapted rehabilitation process, (ii) motivation for RTW and (iii) cognitive abilities and inabilities.The findings indicated that an individually adapted vocational rehabilitation (VR) process was important because the individuals with ABI involved actively in their own rehabilitation process and they required continuous support from the society, the specialists, their employers and colleagues. A moderate level of motivation for RTW was necessary to achieve the best result for RTW and it was important to achieve a balance between too high and too low motivation. Finally, a comprehensive knowledge about the cognitive abilities and inabilities of the individual after ABI helped the individuals and their employers to find compensatory strategies to handle their work tasks.One implication of the findings was the necessity of a good support system and a good VR that functions well and lasts for a longer period. When there are obstacles in the VR process, it is important to have strategies and awareness of how to proceed further.Consequently the support built for a person individually, with a balanced motivation, a high knowledge about the cognitive abilities and awareness of how to proceed further in the process will help to build a successful and sustainable RTW.
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| 9. |
- Matérne, Marie, 1967-, et al.
(författare)
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Opportunities and barriers for successful return to work after acquired brain injury : A patient perspective
- 2017
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Ingår i: Work. - Amsterdam, The Netherlands : IOS Press. - 1051-9815 .- 1875-9270. ; 56:1, s. 125-134
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Tidskriftsartikel (refereegranskat)abstract
- Background: Many people who suffer an acquired brain injury (ABI) are of working age. There are benefits, for the patient, the workplace, and society, to finding factors that facilitate successful return to work (RTW).Objective: The aim was to increase knowledge of opportunities and barriers for a successful RTW in patients with ABI.Method: Five men and five women with ABI participated. All had successfully returned to work at least 20 hours a week. Their experiences were gathered by semi-structured interviews, which were subsequently subjected to qualitative content analysis.Results: Three themes that influenced RTW were identified: individually adapted rehabilitation; motivation for RTW; and cognitive and social abilities. An individually adapted rehabilitation was judged important because the patients were involved in their own rehabilitation and required individually adapted support from rehabilitation specialists, employers, and colleagues. A moderate level of motivation for RTW was needed. Awareness of the person's cognitive and social abilities is essential, in finding compensatory strategies and adaptations.Conclusions: It seems that the vocational rehabilitation process is a balancing act in individualized planning and support, as a partnership with the employer needs to be developed, motivation needs to be generated, and awareness built of abilities that facilitate or hinder RTW.
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| 10. |
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