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| 2. |
- Namazi, A., et al.
(författare)
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LRTM : Life-time and Reliability-aware Task Mapping Approach for Heterogeneous Multi-core Systems
- 2018
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Ingår i: 2018 11th International Workshop on Network on Chip Architectures, NoCArc 2018 - In conjunction with the 51st Annual IEEE/ACM International Symposium on Microarchitecture, MICRO 2018. - : Institute of Electrical and Electronics Engineers Inc.. - 9781538685525
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Konferensbidrag (refereegranskat)abstract
- Technology scaling, increasing number of components in a single chip, and aging effects have brought severe reliability challenges in multi-core platforms. They are more susceptible to faults, both permanent and transient. This paper proposes a Lifetime and Reliability-aware Task Mapping (LRTM) approach to many-core platforms with heterogeneous cores. It tries to confront both transient faults and wear-out failures. Our proposed approach maintains the predefined level of reliability for the task graph in presence of transient faults over the whole lifetime of the system. LRTM uses replication technique with minimum replica overhead, maximum achievable performance, and minimum temperature increase to confront transient faults while increasing the lifetime of the system. Besides, LRTM specifies task migration plans with the minimum overhead using a novel heuristic approach on the occurrence of permanent core failures due to wear-out mechanisms. Task migration scenarios are used during run-time to increase the lifetime of the system while maintaining reliability threshold of the system. Results show the effectiveness of LRTM improves for bigger mesh sizes and higher reliability thresholds. Simulation results obtained from real benchmarks show the proposed approach decreases design-time calculation up to 4371% compared to exhaustive exploration while achieving lifetime negligibly lower than the exhaustive solution (up to 5.83%). LRTM also increases lifetime about 3% compared to other heuristic approaches in the literature.
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| 3. |
- Namazi, A., et al.
(författare)
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Reliability-aware task scheduling using clustered replication for multi-core real-time systems
- 2016
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Ingår i: Proceedings of the 9th International Workshop on Network on Chip Architectures. - New York, NY, USA : ACM. - 9781450347921 ; , s. 45-50
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a model for a new reliability-aware task scheduling method for hard real-time multi-core systems. The proposed method is based on a novel clustered replication which maintains the desired reliability threshold, minimizing both inter-core communication and redundancy overhead in multi-core network-on-chip based platforms. Both single and multiple errors are considered in this method. Experimental results show that the proposed method can schedule hard real-time tasks with relatively lower latency and better communication overhead in comparison with the conventional replication method. The proposed method can reduce the execution latency and communication volume about 29.4% and 30.1% in comparison with conventional replication, respectively. Results show that the redundancy increase of the proposed method is about 60% less than conventional replication and depends on the defined reliability threshold of the system.
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| 4. |
- Barker, D., et al.
(författare)
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Individually addressable double quantum dots formed with nanowire polytypes and identified by epitaxial markers
- 2019
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 114:18
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Tidskriftsartikel (refereegranskat)abstract
- Double quantum dots (DQDs) hold great promise as building blocks for quantum technology as they allow for two electronic states to coherently couple. Defining QDs with materials rather than using electrostatic gating allows for QDs with a hard-wall confinement potential and more robust charge and spin states. An unresolved problem is how to individually address these QDs, which is necessary for controlling quantum states. We here report the fabrication of DQD devices defined by the conduction band edge offset at the interface of the wurtzite and zinc blende crystal phases of InAs in nanowires. By using sacrificial epitaxial GaSb markers selectively forming on one crystal phase, we are able to precisely align gate electrodes allowing us to probe and control each QD independently. We hence observe textbooklike charge stability diagrams, a discrete energy spectrum, and electron numbers consistent with theoretical estimates and investigate the tunability of the devices, finding that changing the electron number can be used to tune the tunnel barrier as expected by simple band diagram arguments.
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| 5. |
- Zamani, Reza, 1982, et al.
(författare)
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Unraveling electronic band structure of narrow-bandgap p-n nanojunctions in heterostructured nanowires
- 2021
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 23:44, s. 25019-25023
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Tidskriftsartikel (refereegranskat)abstract
- The electronic band structure of complex nanostructured semiconductors has a considerable effect on the final electronic and optical properties of the material and, ultimately, on the functionality of the devices incorporating them. Valence electron energy-loss spectroscopy (VEELS) in the transmission electron microscope (TEM) provides the possibility of measuring this property of semiconductors with high spatial resolution. However, it still represents a challenge for narrow-bandgap semiconductors, since an electron beam with low energy spread is required. Here we demonstrate that by means of monochromated VEELS we can study the electronic band structure of narrow-gap materials GaSb and InAs in the form of heterostructured nanowires, with bandgap values down to 0.5 eV, especially important for newly developed structures with unknown bandgaps. Using complex heterostructured InAs-GaSb nanowires, we determine a bandgap value of 0.54 eV for wurtzite InAs. Moreover, we directly compare the bandgaps of wurtzite and zinc blende polytypes of GaSb in a single nanostructure, measured here as 0.84 and 0.75 eV, respectively. This allows us to solve an existing controversy in the band alignment between these structures arising from theoretical predictions. The findings demonstrate the potential of monochromated VEELS to provide a better understanding of the band alignment at the heterointerfaces of narrow-bandgap complex nanostructured materials with high spatial resolution. This is especially important for semiconductor device applications where even the slightest variations of the electronic band structure at the nanoscale can play a crucial role in their functionality.
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