Several classes of algorithms for combinatorial search and optimization problems employ memoization data structures to speed up their serial convergence. However, accesses to these data structures impose dependences t...
详细信息
ISBN:
(纸本)9781450359863
Several classes of algorithms for combinatorial search and optimization problems employ memoization data structures to speed up their serial convergence. However, accesses to these data structures impose dependences that obstruct program parallelization. Such programs often continue to function correctly even when queries into these data structures return a partial view of their contents. Weakening the consistency of these data structures can unleash new parallelism opportunities, potentially at the cost of additional computation. These opportunities must, therefore, be carefully exploited for overall speedup. This paper presents MEMODYN, a framework for parallelizing loops that access data structures with weakly consistent semantics. MEMODYN provides programming abstractions to express weak semantics, and consists of a parallelizing compiler and a runtime system that automatically and adaptively exploit the semantics for optimized parallel execution. Evaluation of MEMODYN shows that it achieves efficient parallelization, providing significant improvements over competing techniques in terms of both runtime performance and solution quality.
This paper presents a framework to develop and execute applications in distributed and highly dynamic computing systems composed of cloud resources and fog devices such as mobile phones, cloudlets, and micro-clouds. T...
详细信息
ISBN:
(数字)9783319751788
ISBN:
(纸本)9783319751788;9783319751771
This paper presents a framework to develop and execute applications in distributed and highly dynamic computing systems composed of cloud resources and fog devices such as mobile phones, cloudlets, and micro-clouds. The work builds on the COMPSs programming framework, which includes a programming model and a runtime already validated in HPC and cloud environments for the transparent execution of parallel applications. As part of the proposed contribution, COMPSs has been enhanced to support the execution of applications on mobile platforms that offer GPUs and CPUs. The scheduling component of COMPSs is under design to be able to offload the computation to other fog devices in the same level of the hierarchy and to cloud resources when more computational power is required. The framework has been tested executing a sample application on a mobile phone offloading task to a laptop and a private cloud.
Smart home IoT devices are becoming increasingly popular. Modern programmable smart home hubs such as SmartThings enable homeowners to manage devices in sophisticated ways to save energy, improve security, and provide...
详细信息
ISBN:
(纸本)9781538694459
Smart home IoT devices are becoming increasingly popular. Modern programmable smart home hubs such as SmartThings enable homeowners to manage devices in sophisticated ways to save energy, improve security, and provide conveniences. Unfortunately, many smart home systems contain vulnerabilities, potentially impacting home security and privacy. This paper presents Vigilia, a system that shrinks the attack surface of smart home IoT systems by restricting the network access of devices. As existing smart home systems are closed, we have created an open implementation of a similar programming and configuration model in Vigilia and extended the execution environment to maximally restrict communications by instantiating device-based network permissions. We have implemented and compared Vigilia with forefront IoT-defense systems;our results demonstrate that Vigilia outper-forms these systems and incurs negligible overhead.
Using the GPUs embedded in mobile devices allows for increasing the performance of the applications running on them while reducing the energy consumption of their execution. This article presents a task-based solution...
详细信息
ISBN:
(纸本)9783319748962;9783319748955
Using the GPUs embedded in mobile devices allows for increasing the performance of the applications running on them while reducing the energy consumption of their execution. This article presents a task-based solution for adaptative, collaborative heterogeneous computing on mobile cloud environments. To implement our proposal, we extend the COMPSs-Mobile framework - an implementation of the COMPSs programming model for building mobile applications that offload part of the computation to the Cloud - to support offloading computation to GPUs through OpenCL. To evaluate our solution, we subject the prototype to three benchmark applications representing different application patterns.
This paper describes the software implementation of an emerging parallel programming model for partitioned global address space (PGAS) architectures. Applications with irregular memory access to distributed memory do ...
详细信息
ISBN:
(纸本)9783319937137;9783319937120
This paper describes the software implementation of an emerging parallel programming model for partitioned global address space (PGAS) architectures. Applications with irregular memory access to distributed memory do not perform well on conventional symmetric multiprocessing (SMP) architectures with hierarchical caches. Such applications tend to scale with the number of memory interfaces and corresponding memory access latency. Using a remote procedure call (RPC) technique, these applications may see reduced latency and higher throughput compared to remote memory access or explicit message passing. The software implementation of a remote procedure call method detailed in the paper is designed for the low-power Adapteva Epiphany architecture.
Interval fuzzy preference relations (IFPRs) that can simply denote the lower and upper bounds of decision makers' uncertain judgments are keenly studied by researchers and are widely used in practical decision-mak...
详细信息
Interval fuzzy preference relations (IFPRs) that can simply denote the lower and upper bounds of decision makers' uncertain judgments are keenly studied by researchers and are widely used in practical decision-making problems. Consistency analysis is vitally important to avoid illogical ranking orders. First, this paper analyzes issues in previous additive consistency concepts for IFPRs. Then, it presents a new additive consistency definition that overcomes issues in previous ones. A linear programming model to judge the additive consistency of IFPRs is constructed, and a method to derive additive consistent IFPRs is proposed. Furthermore, a goal programming model to determine missing values in an incomplete IFPR is built, which have the highest consistent level with respect to known values. Regarding group decision making, a group consensus index is defined to measure the consensus of individual IFPRs, and an approach to improve the consensus level is introduced. Finally, a method for group decision making with IFPRs is developed, which can address incomplete and inconsistent cases. Associated examples are given to show the efficiency and feasibility of the developed theoretical results and comparative analysis is made.
Triangular fuzzy reciprocal preference relations (TFRPRs) are good choices to denote the decision makers' fuzzy preferences. Consistency analysis is a very important topic to preference relations that can avoid th...
详细信息
Triangular fuzzy reciprocal preference relations (TFRPRs) are good choices to denote the decision makers' fuzzy preferences. Consistency analysis is a very important topic to preference relations that can avoid the illogical ranking order. However, all previous multiplicative consistency concepts for TFRPRs cannot well address this type of preference relations. To address this issue, this paper introduces a new multiplicative consistency concept for TFRPRs, which can be seen as a natural extension of Tanino's multiplicative consistency concept for reciprocal preference relations. Based on the new consistency concept, 0-1 mixed' programming models for judging the multiplicative consistency of TFRPRs are constructed, and an approach for deriving multiplicative consistent TFRPRs is provided. Considering the incomplete case, programming models to determine missing values ate constructed. Subsequently, a multiplicative consistency based method for decision making with TFRPRs is presented that can address the inconsistent and incomplete cases. Meanwhile, illustrative examples are provided to show the concrete application of the proposed procedure, and comparison analysis is also made. (C) 2016 Elsevier B.V. All rights reserved.
Cyber-Physical Systems (CPSs) are widely used in many applications that require interactions between humans and their physical environment. These systems usually integrate a set of hardware-software components for opt...
详细信息
Cyber-Physical Systems (CPSs) are widely used in many applications that require interactions between humans and their physical environment. These systems usually integrate a set of hardware-software components for optimal application execution in terms of performance and energy consumption. The AXIOM project (Agile, eXtensible, fast I/O Module), presented in this paper, proposes a hardware-software platform for CPS coupled with an easy parallel programming model and sufficient connectivity so that the performance can scale-up by adding multiple boards. AXIOM supports a task-based programming model based on OmpSs and leverages a high-speed, inexpensive communication interface called AXIOM-Link. The board also tightly couples the CPU with reconfigurable resources to accelerate portions of the applications. As case studies, AXIOM uses smart video surveillance, and smart home living applications. (C) 2017 Elsevier B.V. All rights reserved.
A disruptive technology that is influencing not only computing paradigm but every other business is the rise of big data. Internet of Things (loT) applications are considered to be a major source of big data. Such loT...
详细信息
A disruptive technology that is influencing not only computing paradigm but every other business is the rise of big data. Internet of Things (loT) applications are considered to be a major source of big data. Such loT applications are in general supported through clouds where data is stored and processed by big data processing systems. In order to improve the efficiency of cloud infrastructure so that they can efficiently support loT big data applications, it is important to understand how these applications and the corresponding big data processing systems will perform in cloud computing environments. However, given the scalability and complex requirements of big data processing system5, an empirical evaluation on actual cloud infrastructure can hinder the development of timely and cost effective loT solutions. Therefore, a simulator supporting MT applications in cloud environment is highly demanded, but such work is still in its infancy. To fill this gap, we have designed and implemented IOTSim which supports and enables simulation of loT big data processing using MapReduce model in cloud computing environment. A real case study validates the efficacy of the simulator. (C) 2016 Elsevier B.V. All rights reserved.
To examine the multiplicative consistency of interval fuzzy preference relations (IFPRs), this paper first analyzes the limitations associated with the previous consistency concepts. Accordingly, a new consistency con...
详细信息
To examine the multiplicative consistency of interval fuzzy preference relations (IFPRs), this paper first analyzes the limitations associated with the previous consistency concepts. Accordingly, a new consistency concept is defined that is an extension of the crisp case and overcomes limitations in the previous concepts. Next, a linear programming model to judge the consistency of IFPRs is constructed, and an approach to derive multiplicative consistent IFPRs is introduced. Furthermore, goal-programming models to determine missing values in an incomplete IFPR are constructed that have the highest consistent level with respect to known values. Moreover, a multiplicative consistency and consensus based method for group decision making with IFPRs is developed that can address incomplete and inconsistent cases. Finally, two practical decision-making problems are offered to demonstrate the feasibility and efficiency of the new method, and an analysis of a numerical and theoretical comparison with several related methods is performed. (C) 2016 Elsevier Ltd. All rights reserved.
暂无评论