| 1. |
- Riedel, M., et al.
(författare)
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Improving e-Science with Interoperability of the e-Infrastructures EGEE and DEISA
- 2008
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Ingår i: MIPRO 2008 - 31st International Convention Proceedings. - 9789532330366 ; , s. 225-231
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Konferensbidrag (refereegranskat)abstract
- In the last couple of years, many e-Science infrastructures have begun to offer production services to e- Scientists with an increasing number of applications that require access to different kinds of computational resources. Within Europe two rather different multi-national e-Science infrastructures evolved over time namely Distributed European Infrastructure for Supercomputing Applications (DEISA) and Enabling Grids for E-SciencE (EGEE). DEISA provides access to massively parallel systems such as supercomputers that are well suited for scientific applications that require many interactions between their typically high numbers of CPUs. EGEE on the other hand provides access to a world-wide Grid of university clusters and PC pools that are well suited for farming applications that require less or even no interactions between the distributed CPUs. While DEISA uses the HPC-driven Grid technology UNICORE, EGEE is based on the gLite Grid middleware optimized for farming jobs. Both have less adoption of open standards and therefore both systems are technically non-interoperable, which means that no e-Scientist can easily leverage the DEISA and EGEE infrastructure with one suitable client environment for scientific applications. This paper argues that future interoperability of such large e-Science infrastructures is required to improve e-Science in general and to increase the real scientific impact of world-wide Grids in particular. We discuss the interoperability achieved by the OMII-Europe project that fundamentally improved the interoperability between UNICORE and gLite by using open standards. We also outline one specific scientific scenario of the WISDOM initiative that actually benefits from the recently established interoperability.
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| 2. |
- Ali, R., et al.
(författare)
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Computational analysis of PT/CT contact behavior for a heavy water reactor at high temperature and pressure
- 2018
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Ingår i: Proceedings of 2018 15th International Bhurban Conference on Applied Sciences and Technology, IBCAST 2018. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538635643 ; , s. 645-650
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Konferensbidrag (refereegranskat)abstract
- A computational model has been developed for a heavy water reactor (HWR) reactor to analyze the temperature distribution of the moderator and pressure tube and to determine the thermal stress analysis of pressure tube (PT) using the non linear elastic model for thermal expansion. For an IAEA ICSP problem, the experimental set up and model were developed by the Fuel Channel High Temperature Heat Transfer (FCHTHT) laboratory in Canada. In case of LOCA or primary heat transfer failure, PT experiences a significant heat flux that results in ballooning of PT. Following the PT deformation, PT/CT contact may occur and thus there is spike in heat flux at calandria tube (CT) resulting in the local dryout of CT. The study was divided into two parts, pre-contact phase and contact phase. The analysis is made by using the COMSOL multiphysics software. The results reveal the effect of buoyancy and support the validation of experimental set up where the graphite heater is offset below the centre to account for the buoyancy effects. The PT was deformed at higher temperature and came in contact at 74.4 seconds.
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| 3. |
- Baus, M, et al.
(författare)
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Monolithic Bidirectional Switch (MBS) - A novel MOS-based power device
- 2005
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Ingår i: PROCEEDINGS OF ESSDERC 2005. - 0780392035 ; , s. 473-476
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Konferensbidrag (refereegranskat)abstract
- A novel MOS-based power device, the Monolithic Bidirectional Switch (MBS), is investigated in this work. An analytical model is used to explain basic device operating principles. A self-aligned fabrication process of lateral MBS devices with Schottky contacts and local oxidation of silicon technique (LOCOS) is described. Experimental results are compared with the analytical model to analyze the influence of device parasitics. Bidirectional switching and an on/off-current ratio of more than 100 is demonstrated for MBS devices for the first time.
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| 4. |
- Bessani, A., et al.
(författare)
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BiobankCloud : A platform for the secure storage, sharing, and processing of large biomedical data sets
- 2016
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Ingår i: 1st International Workshop on Data Management and Analytics for Medicine and Healthcare, DMAH 2015 and Workshop on Big-Graphs Online Querying, Big-O(Q) 2015 held in conjunction with 41st International Conference on Very Large Data Bases, VLDB 2015. - Cham : Springer. - 9783319415758 - 9783319415765 ; , s. 89-105
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Konferensbidrag (refereegranskat)abstract
- Biobanks store and catalog human biological material that is increasingly being digitized using next-generation sequencing (NGS). There is, however, a computational bottleneck, as existing software systems are not scalable and secure enough to store and process the incoming wave of genomic data from NGS machines. In the BiobankCloud project, we are building a Hadoop-based platform for the secure storage, sharing, and parallel processing of genomic data. We extended Hadoop to include support for multi-tenant studies, reduced storage requirements with erasure coding, and added support for extensible and consistent metadata. On top of Hadoop, we built a scalable scientific workflow engine featuring a proper workflow definition language focusing on simple integration and chaining of existing tools, adaptive scheduling on Apache Yarn, and support for iterative dataflows. Our platform also supports the secure sharing of data across different, distributed Hadoop clusters. The software is easily installed and comes with a user-friendly web interface for running, managing, and accessing data sets behind a secure 2-factor authentication. Initial tests have shown that the engine scales well to dozens of nodes. The entire system is open-source and includes pre-defined workflows for popular tasks in biomedical data analysis, such as variant identification, differential transcriptome analysis using RNA-Seq, and analysis of miRNA-Seq and ChIP-Seq data.
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| 5. |
- Marzolla, M., et al.
(författare)
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Open standards-based interoperability of job submission and management interfaces across the grid middleware platforms gLite and UNICORE
- 2007
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Ingår i: Proceedings - e-Science 2007, 3rd IEEE International Conference on e-Science and Grid Computing. - : IEEE Computer Society. - 0769530648 - 9780769530642 ; , s. 592-599
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Konferensbidrag (refereegranskat)abstract
- In a distributed Grid environment with ambitious service demands the job submission and management interfaces provide functionality of major importance. Emerging e-Science and Grid infrastructures such as EGEE and DEISA rely on highly available services that are capable of managing scientific jobs. It is the adoption of emerging open standard interfaces which allows the distribution of Grid resources in such a way that their actual service implementation or Grid technologies are not isolated from each other, especially when these resources are deployed in different e-Science infrastructures that consist of different types of computational resources. This paper motivates the interoperability of these infrastructures and discusses solutions. We describe the adoption of various open standards that recently emerged from the Open Grid Forum (OGF) in the field of job submission and management by well-known Grid technologies, respectively gLite and UNICORE. This has a fundamental impact on the interoperability between these technologies and thus within the next generation e-Science infrastructures that rely on these technologies.
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| 6. |
- Ali, Mai, et al.
(författare)
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Autonomous Patient/Home Health Monitoring powered by Energy Harvesting
- 2017
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Ingår i: Globecom 2017 - 2017 IEEE Global Communications Conference. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781509050192
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Konferensbidrag (refereegranskat)abstract
- This paper presents the design of an autonomous smart patient/home health monitoring system. Both patient physiological parameters as well as room conditions are being monitored continuously to insure patient safety. The sensors are connected on an IoT regime, where the collected data is wirelessly transferred to a nearby gateway which performs preliminary data analysis, commonly referred to as fog computing, to make sure emergency personnel and healthcare providers are notified in case patient being monitored is at risk. To achieve power autonomy three energy harvesting sources are proposed, namely, solar, RF and thermal. The design of the RF energy harvesting system is demonstrated, where novel multiband antenna is fabricated as well as an efficient RF-DC rectifier achieving maximum conversion efficiency of 84%. Finally, the sensor node is tested with different type of sensors and settings while being solely powered by a Photovoltaic (PV) solar cell.
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| 7. |
- Bailis, P., et al.
(författare)
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Bolt-on causal consistency
- 2013
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Ingår i: SIGMOD '13 Proceedings of the 2013 ACM SIGMOD International Conference on Management of Data. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450320375 ; , s. 761-772
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Konferensbidrag (refereegranskat)abstract
- We consider the problem of separating consistency-related safety properties from availability and durability in distributed data stores via the application of a "bolt-on" shim layer that upgrades the safety of an underlying general-purpose data store. This shim provides the same consistency guarantees atop a wide range of widely deployed but often inflexible stores. As causal consistency is one of the strongest consistency models that remain available during system partitions, we develop a shim layer that upgrades eventually consistent stores to provide convergent causal consistency. Accordingly, we leverage widely deployed eventually consistent infrastructure as a common substrate for providing causal guarantees. We describe algorithms and shim implementations that are suitable for a large class of application-level causality relationships and evaluate our techniques using an existing, production-ready data store and with real-world explicit causality relationships.
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| 8. |
- Bailis, P., et al.
(författare)
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HAT, not CAP : Towards highly available transactions
- 2013
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Ingår i: 14th Workshop on Hot Topics in Operating Systems, HotOS 2013. - : USENIX Association.
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Konferensbidrag (refereegranskat)abstract
- While the CAP Theorem is often interpreted to preclude the availability of transactions in a partition-prone environment, we show that highly available systems can provide useful transactional semantics, often matching those of today's ACID databases. We propose Highly Available Transactions (HATs) that are available in the presence of partitions. HATs support many desirable ACID guarantees for arbitrary transactional sequences of read and write operations and permit low-latency operation.
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| 9. |
- Bailis, P., et al.
(författare)
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The potential dangers of causal consistency and an explicit solution
- 2012
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Ingår i: Proceedings of the 3rd ACM Symposium on Cloud Computing, SoCC 2012. - New York, NY, USA : ACM. - 9781450317610
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Konferensbidrag (refereegranskat)abstract
- Causal consistency is the strongest consistency model that is available in the presence of partitions and provides useful semantics for human-facing distributed services. Here, we expose its serious and inherent scalability limitations due to write propagation requirements and traditional dependency tracking mechanisms. As an alternative to classic potential causality, we advocate the use of explicit causality, or application-defined happens-before relations. Explicit causality, a subset of potential causality, tracks only relevant dependencies and reduces several of the potential dangers of causal consistency.
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| 10. |
- El Tom, Ali, et al.
(författare)
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Criteria Based Evaluation of Cross-Platform Development Frameworks
- 2023
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Ingår i: Proceedings of the 56th Annual Hawaii International Conference on System Sciences, HICSS 2023. - : IEEE Computer Society. ; , s. 6944-6953
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Konferensbidrag (refereegranskat)abstract
- Cross-platform development frameworks continue to play an important role in developing of mobile applications. There are a plethora of possible frameworks to choose between, and all claim to give developers an advantage in one or more aspects of the development cycle. To further shed light on this area, our research investigates the selection of mobile cross-platform frameworks by investigating criteria and methods for choosing the best suitable framework for the development context. Our study confirm previous research findings and with that anchor the categorisation for a cross-platform comparison taxonomy. Our research further contribute with a criteria check-list to apply for cross-platform framework selection and showcase its use through a comparative study of a cross-platform application implemented in two frameworks. Although showcasing novelty in the criteria checklist, further research is needed to make the checklist robust and streamlined for public use.
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