| 1. |
- Abdullah, Jakaria, et al.
(författare)
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Towards a Tool : TIMES-Pro for Modeling, Analysis, Simulation and Implementation of Cyber-Physical Systems
- 2017
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Ingår i: MODELS, ALGORITHMS, LOGICS AND TOOLS. - Cham : SPRINGER INTERNATIONAL PUBLISHING AG. - 9783319631219 - 9783319631202 ; , s. 623-639
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Konferensbidrag (refereegranskat)abstract
- We consider a Cyber-Physical System (CPS) as a network of components that are either physical plants with continuous behaviors or discrete controllers. To build CPS's in a systematic manner, the TIMES-Pro tool is designed to support modeling, analysis and code generation for real-time simulation and final deployment. In this paper, we present our decisions in designing the modeling language, the tool architecture and features of TIMES-Pro, and also a case study to demonstrate its applicability.
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| 2. |
- Axer, Philip, et al.
(författare)
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Building Timing Predictable Embedded Systems
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A large class of embedded systems is distinguished from general purpose computing systems by the need to satisfy strict requirements on timing, often under constraints on available resources. Predictable system design is concerned with the challenge of building systems for which timing requirements can be guaranteed a priori. Perhaps paradoxically, this problem has become more difficult by the introduction of performance-enhancing architectural elements, such as caches, pipelines, and multithreading, which introduce a large degree of nondeterminism and make guarantees harder to provide. The intention of this paper is to summarize current state-of-the-art in research concerning how to build predictable yet performant systems. We suggest precise definitions for the concept of “predictability”, and present predictability concerns at different abstractions levels in embedded software design. First, we consider timing predictability of processor instruction sets. Thereafter, We consider how programming languages can be equipped with predictable timing semantics, covering both a language-based approach based on the synchronous paradigm, as well as an environment that provides timing semantics for a mainstream programming language (in this case C). We present techniques for achieving timing predictability on multicores. Finally we discuss how to handle predictability at the level of networked embedded systems, where randomly occurring errors must be considered.
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| 3. |
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| 4. |
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| 5. |
- Birney, Ewan, et al.
(författare)
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Identification and analysis of functional elements in 1% of the human genome by the ENCODE pilot project
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 447:7146, s. 799-816
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Tidskriftsartikel (refereegranskat)abstract
- We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.
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| 6. |
- Chen, Gang, et al.
(författare)
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EDF-VD Scheduling of Flexible Mixed-Criticality System With Multiple-Shot Transitions
- 2018
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Ingår i: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems. - 0278-0070 .- 1937-4151. ; 37:11, s. 2393-2403
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Tidskriftsartikel (refereegranskat)abstract
- The existing mixed-criticality (MC) real-time task models assume that once any high-criticality task overruns, all high-criticality jobs execute up to their most pessimistic WCET estimations simultaneously in a one-shot manner. This is very pessimistic in the sense of unnecessary resource overbooking. In this paper, we propose a more generalized mixed-critical real-time task model, called flexible MC model with multiple-shot transitions (FMC-MST), to address this problem. In FMC-MST, high-criticality tasks can transit multiple intermediate levels to handle less pessimistic overruns independently and to nonuni-formly scale the deadline on each level. We develop a run-time schedulability analysis for FMC-MST under EDF-VD scheduling, in which a better tradeoff between the penalties of low-criticality tasks and the overruns of high-criticality tasks is achieved to improve the service quality of low-criticality tasks. We also develop a resource optimization technique to find resource-efficient level-insertion configurations for FMC-MST task systems under MC timing constraints. Experiments demonstrate the effectiveness of FMC-MST compared with the state-of-the-art techniques.
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| 7. |
- Chen, Gang, et al.
(författare)
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Fault-tolerant real-time tasks scheduling with dynamic fault handling
- 2020
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Ingår i: Journal of systems architecture. - : ELSEVIER. - 1383-7621 .- 1873-6165. ; 102
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Tidskriftsartikel (refereegranskat)abstract
- Predictable performance when coping with transient failures is of paramount importance in safety-critical real-time systems. Various software fault-tolerant techniques are employed towards this goal among which check-pointing is a relatively cost-effective scheme. In this paper, we propose an efficient fault-tolerant scheduling framework with run-time fault handling protocol, where criticality levels can be adaptively inserted for fault handling according to run-time fault workload. In contrast to prior works which apply with task re-execution strategy, the proposed framework adaptively determines on-demand re-executions only on the faulty checkpoint segments, rather than on the whole job. Towards this, a unified overrun handling protocol is developed to handle fault recovery adaptively to avoid over-provisioning of resources. In addition, we develop an off-line schedulability analysis technique for the proposed scheduling algorithm. The simulation results show that our fault-tolerant scheduling framework can bring up to 81% improvement in supporting low-criticality service without sacrifice in the MC-schedulability compared with the existing techniques.
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| 8. |
- Chen, Gang, et al.
(författare)
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Utilization-Based Scheduling of Flexible Mixed-Criticality Real-Time Tasks
- 2018
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Ingår i: IEEE Transactions on Computers. - : IEEE COMPUTER SOC. - 0018-9340 .- 1557-9956. ; 67:4, s. 543-558
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Tidskriftsartikel (refereegranskat)abstract
- Mixed-criticality models are an emerging paradigm for the design of real-time systems because of their significantly improved resource efficiency. However, formal mixed-criticality models have traditionally been characterized by two impractical assumptions: once any high-criticality task overruns, all low-criticality tasks are suspended and all other high-criticality tasks are assumed to exhibit high-criticality behaviors at the same time. In this paper, we propose a more realistic mixed-criticality model, called the flexible mixed-criticality (FMC) model, in which these two issues are addressed in a combined manner. In this new model, only the overrun task itself is assumed to exhibit high-criticality behavior, while other high-criticality tasks remain in the same mode as before. The guaranteed service levels of low-criticality tasks are gracefully degraded with the overruns of high-criticality tasks. We derive a utilization-based technique to analyze the schedulability of this new mixed-criticality model under EDF-VD scheduling. During run time, the proposed test condition serves an important criterion for dynamic service level tuning, by means of which the maximum available execution budget for low-criticality tasks can be directly determined with minimal overhead while guaranteeing mixed-criticality schedulability. Experiments demonstrate the effectiveness of the FMC scheme compared with state-of-the-art techniques.
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| 9. |
- Deng, Min, et al.
(författare)
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Genome-wide association analyses in Han Chinese identify two new susceptibility loci for amyotrophic lateral sclerosis
- 2013
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 45:6, s. 697-
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Tidskriftsartikel (refereegranskat)abstract
- To identify susceptibility genes for amyotrophic lateral sclerosis (ALS), we conducted a genome-wide association study (GWAS) in 506 individuals with sporadic ALS and 1,859 controls of Han Chinese ancestry. Ninety top SNPs suggested by the current GWAS and 6 SNPs identified by previous GWAS were analyzed in an independent cohort of 706 individuals with ALS and 1,777 controls of Han Chinese ancestry. We discovered two new susceptibility loci for ALS at 1q32 (CAMK1G, rs6703183, P-combined = 2.92 x 10(-8), odds ratio (OR) = 1.31) and 22p11 (CABIN1 and SUSD2, rs8141797, P-combined = 2.35 x 10(-9), OR = 1.52). These two loci explain 12.48% of the overall variance in disease risk in the Han Chinese population. We found no association evidence for the previously reported loci in the Han Chinese population, suggesting genetic heterogeneity of disease susceptibility for ALS between ancestry groups. Our study identifies two new susceptibility loci and suggests new pathogenic mechanisms of ALS.
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