Path planning is one of the most computation expensive tasks in the field of mobile robotics especially in dynamically changing environments. It is difficult to meet realtime requirements with serial path planning alg...
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ISBN:
(纸本)9780889867741
Path planning is one of the most computation expensive tasks in the field of mobile robotics especially in dynamically changing environments. It is difficult to meet realtime requirements with serial path planning algorithms. This would require a high speed processor. Particularly in small autonomous robot systems, this is inefficient due to the energy consumption and space requirement. In contrast, we propose a parallel path planning approach based on Marching Pixels which is a new innovative Organic computing principle. It can be used as coarse global path planner in dynamically changing environments because the algorithm is very fast and only requires few resources.
Large-scale parallel and distributedcomputing environments have several problems concerning power consumption, thermal ascent, and setting space. In particular, power consumption and thermal ascent are the two seriou...
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ISBN:
(纸本)9780889867741
Large-scale parallel and distributedcomputing environments have several problems concerning power consumption, thermal ascent, and setting space. In particular, power consumption and thermal ascent are the two serious problems that have to be taken care of when a system is used for a long time. We had proposed a CPU power control and scheduling technique (PCST) for realtime parallel and distributedcomputingsystems in order to solve the abovementioned problems;in these systems, the processors can change the frequencies and voltages. In this study, we evaluate the PCST by using the tracking program. The evaluation results show that when the PCST is employed, the power consumption is 60%-80% when compared to that of the commercial power control;moreover, when compared to that of the no power control, the power consumption is only 20%-40%.
Program analysis supporting software development is often part of edit-compile-cycles and precise program analysis is time consuming. With the availability parallel processing power on desktop computers, paral-lelizat...
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ISBN:
(纸本)9780889867741
Program analysis supporting software development is often part of edit-compile-cycles and precise program analysis is time consuming. With the availability parallel processing power on desktop computers, paral-lelization is a way to speed up program analysis. This paper introduces a parallelization schema for program analysis that can be translated to parallel machines using standard scheduling techniques. First benchmarks analyzing a number of Java programs indicate that the schema scales well for up to 8 processors, but not very well for 128 processors. These results are a first step towards more precise program analysis in Integrated Development Environments utilizing the computational power of today's custom computers.
Current visual text mining platforms are still focused on small or medium-scale datasets and sequential algorithms. However, as document collections increase in size and complexity, more computing resources are requir...
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ISBN:
(纸本)9780889867741
Current visual text mining platforms are still focused on small or medium-scale datasets and sequential algorithms. However, as document collections increase in size and complexity, more computing resources are required in order to achieve the expected interactive experience. In order to address the scalability problem, this paper proposes and evaluates parallel implementations for three critical visual text mining algorithms. Experiments with the parallel solutions were conducted for varying dataset sizes and different numbers of processors. The results show a good speedup for the proposed solutions and indicate the potential benefits of exploring task parallelism in critical algorithms to improve scalability of an interactive visual text mining platform.
While distributed multi-agent systems are especially suitable for taking advantage of the capacity for evolution and adaptation in ubiquitous computing, writing such programs is a difficult and complicated task if not...
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ISBN:
(纸本)9780889867741
While distributed multi-agent systems are especially suitable for taking advantage of the capacity for evolution and adaptation in ubiquitous computing, writing such programs is a difficult and complicated task if not supported by an agent programming framework. This paper presents a real-time agent service layer (RT-ASL) that is built on an existing de facto standard for interconnecting distributed objects, CORBA middleware. RT-ASL enables programmers to write distributed cooperative application programs for ubiquitous computing using a high-level abstraction of software agents. As criteria for designing RT-ASL on CORBA, we have made four important decisions regarding the message passing communication mechanism for agent communications, agent service discovery mechanism, real-time agent communication language, and real-time generic scheduling interfaces. This paper justifies the importance of such design decisions and how they can effectively deal with the complicated difficulties.
Scheduling the execution of computing tasks for heterogeneous computingsystems is a widely studied problem in the field of parallel and distributedcomputing. Many algorithms belong to list scheduling algorithms in w...
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ISBN:
(纸本)9780889867741
Scheduling the execution of computing tasks for heterogeneous computingsystems is a widely studied problem in the field of parallel and distributedcomputing. Many algorithms belong to list scheduling algorithms in which tasks are scheduled sequentially in the order of their pre-assigned priorities. The determination of task priorities is typically based on problem-specific heuristics, which is critical to the performance of a list scheduling algorithm. We design a list scheduling algorithm for heterogeneous computingsystems in which task priorities are determined by both the completion time and upward rank of a task. We extend the notion of upward ranks used in HEFT and our method of calculating a task's upward rank improves over the method used in HEFT, with the inclusion of additional domain knowledge embedded in scheduling problems. As a result, more accurate estimation of the execution time of remaining tasks can be achieved. Experimental results on benchmark task graphs show that our algorithm consistently outperforms HEFT with higher execution speedups.
In this paper, we provide an "Improved Channel Aware QoS Scheduling Architecture for WiMAX Base Stations". In this scheme, we provide intelligence to the classifier by having feedback from the compensation b...
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ISBN:
(纸本)9780889867741
In this paper, we provide an "Improved Channel Aware QoS Scheduling Architecture for WiMAX Base Stations". In this scheme, we provide intelligence to the classifier by having feedback from the compensation block. We capitalize on the design of WiMAX, which differentiates connections with separate connection IDs and classifies traffic, based on a class-based approach. We propose a design in which the Classifier, in order to provide excellent QoS, admits frames with only those CIDs that can be serviced without any significant delay to the real time voice and video applications, thus improving the overall QoS. In other words, it rejects a packet having a CID which is experiencing bad channel quality and allows unmarked CIDs to utilize the channel at its maximum efficiency.
In engineering applications often real-valued performance functions must be optimized. If the performance function is discontinuous, there exist no derivations with respect to the parameters that should be optimized. ...
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ISBN:
(纸本)9780889867741
In engineering applications often real-valued performance functions must be optimized. If the performance function is discontinuous, there exist no derivations with respect to the parameters that should be optimized. Thus, we can only use undirected search methods. In contrast to simple trial-and-error approaches, evolutionary strategies can extract population-based information that guide the search process and help to improve the quality of the results. The paper describes the parallel implementation of an state-of-the-art evolutionary strategy which uses the covariance adaptation operator. It proposes a communication topology for maintaining selective pressure and a master-slave scheme for fault tolerance in distributed environments which are composed of volatile resources. Experimental results demonstrate how the implementation can be adapted to specific needs and how the parallel implementation behaves in the case of resource failures.
Currently, middleware systems for Grid computing like gLite do not integrate knowledge about data availability into the scheduling process. That is, data may be on tertiary storage, e.g. hierarchical storage managemen...
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ISBN:
(纸本)9780889867741
Currently, middleware systems for Grid computing like gLite do not integrate knowledge about data availability into the scheduling process. That is, data may be on tertiary storage, e.g. hierarchical storage management, and first access is delayed. To this end, we investigate the gLite middleware software stack and highlight those services which could be enhanced to increase system utilization. Here, we focus on modifications of the workload management system and the computing element. As the computing element depends on a resource management system, we discuss the impact of file systems on the scheduling process. Optimizing the LHCb job workflow, we design a scheduling strategy which respects those constraints. Conceptually, this strategy performs a co-allocation of data movements concurrently to computational processes. Based on a workload trace from the parallel Workload Archive we are able to present improvements in terms of system utilization and average weighted response time.
As information systems develop into larger and more complex implementations, the need for survivability increases. When components are exported from a remote system to a local system under different administrative set...
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ISBN:
(纸本)9780889867741
As information systems develop into larger and more complex implementations, the need for survivability increases. When components are exported from a remote system to a local system under different administrative settings and deployed in different environments we have to guarantee the proper execution of those remote components in the currently working environment because the remote components may have failures or malicious codes that can affect the local computing environment. In this paper, we address a multiple-aspect testing approach, which is able to increase the possibility of detecting a fault in a component by having various ways possible to conduct the test on the components. We have implemented a prototype that provides for the multiple-aspect testing for the downloaded components in runtime without access to the source code. Finally, the implementation of the multiple-aspect testing is evaluated and analyzed in terms of detection performance and accuracy.
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