Withthe increasing penetration of renewable energy sources into modern power system especially in a microgrid form, power inverters are commonly employed as the interface to the utility grid. LCL-filters are commonly...
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ISBN:
(纸本)9781467386173
Withthe increasing penetration of renewable energy sources into modern power system especially in a microgrid form, power inverters are commonly employed as the interface to the utility grid. LCL-filters are commonly used in interfacing inverters, in order to reduce the harmonics around the switching frequency and its multiples. However, unlike the single gridconnected inverter system where the resonance frequency is mainly fixed by the inverter output LCL filter parameters, the parallel-inverter-based grid-interactive power system presents a more challenging picture where inverter interactions will excite complex resonances at various frequencies. In this paper, an adaptive optimal feedback control is proposed to address system uncertain multi-resonance problem in the parallel-connected inverter system with LCL filters. the proposed adaptive control will force the inverter by modifying state-feedback optimal control law adaptively to follow the desired system response, thus significantly improve the grid current quality under various grid conditions. Experimental results have verified the performance of the proposed adaptive control.
In the paper, we propose a generic parallelcomputing model for the distributedcomputing platforms. this model is built on the top of the popular CORBA middleware in order to ensure easy distribution of the software ...
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ISBN:
(纸本)9780769527369
In the paper, we propose a generic parallelcomputing model for the distributedcomputing platforms. this model is built on the top of the popular CORBA middleware in order to ensure easy distribution of the software components along the participating computers. We use the concept of factory objects in the model to create slave objects dynamically to fulflll the master/slave parallelcomputing paradigm. the speedup of the experiment programs using our proposed model is measured and compared withthe corresponding A PI implementation. the experiment results show that our model is not only a feasible model for designing parallel programs with CORBA but also an efficient way in comparison to the MPI implementation.
While recently the focus of architects and programmers has been on multi core, the alternative of processor node plus array oriented accelerator has some significant advantages especially in Compute intensive static a...
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ISBN:
(纸本)9780769534725
While recently the focus of architects and programmers has been on multi core, the alternative of processor node plus array oriented accelerator has some significant advantages especially in Compute intensive static applications. We propose an acceleration methodology based on FPGA arrays (but, in principle it could be GPU or Cell based). the methodology, uses a comprehensive application analysis supported by high performance FPGA hardware. the analysis provides a dataflow graph of the application which is replicated in SIMD for multiple data strips (until limited by the pin bandwidth, then pipelined (MISD) until circuit limited. An oil exploration application shows the possibility of speedup of over 300x over an Intel Xeon.
this study describes a preliminary research on Information Retrieval (IR) systems. We developed a prototype tool that runs on a master-slave model and uses distributed processing in order to decentralize the workload ...
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ISBN:
(纸本)9781467308946;9788994364261
this study describes a preliminary research on Information Retrieval (IR) systems. We developed a prototype tool that runs on a master-slave model and uses distributed processing in order to decentralize the workload while retrieving information from the Internet. Later, its viability is demonstrated with a set of executions and the discussion follows with an analysis of the master process overload versus the number of slaves connected.
In this work, we present methods for distributed domain generation within the constraints of our decentral domain management concept. Here, all participating actors only have knowledge of their immediate neighbours, w...
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ISBN:
(纸本)9781665432818
In this work, we present methods for distributed domain generation within the constraints of our decentral domain management concept. Here, all participating actors only have knowledge of their immediate neighbours, which are defined by geometric and hierarchical relations between nodes that represent subsets of the computational domain. We generate this domain following a hierarchical spacetree refinement. First, an initial tree is generated on every participating process. Second, this tree is distributed following a space-filling curve linearisation locally. Every process is assigned at least one leaf node of the initial tree, which acts as a starting point for the subsequent domain generation. From here, every process independently refines a subdomain using a decomposition method, which transforms a triangular surface-based geometry description into a volume-based one, using increasingly complex intersection tests. the resulting domain tree is distributed, yet neighbourhood references of neighbouring subtrees are not resolved. We combine the resolution of these relations with a 2:1 tree balancing, which involves the transfer of the surface of neighbouring subtrees. We provide results of a domain generation testcase, using an input geometry with 84,072 triangles on up to 896 processes of the CoolMUC-2 cluster segment of LRZ's Linux Cluster System. Here, we bring down the overall time it takes to generate an adaptively refined and balanced octree with depth d = 7 from 5.5 hours on one process to two seconds on 896 processes.
Commercial cloud systems allow massively parallel execution of a computing task for little money. We want to exploit this economic opportunity by solving classical problems in Operations Research through complete enum...
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ISBN:
(纸本)9781467395601
Commercial cloud systems allow massively parallel execution of a computing task for little money. We want to exploit this economic opportunity by solving classical problems in Operations Research through complete enumeration, especially if these problems can be expressed as integer programming problems. We propose and evaluate here a data structure, Scalable Virtual distributed Hashing, that autonomously extends the computing task over as many nodes as are needed in order return a result within a time limit set by the user. Our data structure deals with varying and changing node capacities and the effects of node failures. It is modeled after Scalable distributed Data Structures and Extendible Hashing in particular.
Withthe rapid development and popularization of CFD technology, requirements on data amount and computing speed have also increased a lot. the computing ability of single CPU is unable to meet the requirement. theref...
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ISBN:
(纸本)9781479966363
Withthe rapid development and popularization of CFD technology, requirements on data amount and computing speed have also increased a lot. the computing ability of single CPU is unable to meet the requirement. therefore, iteration and parallel computation are the most important methods for CFD problems with large grid scales. this paper introduces the most popular iteration methods, classical iteration methods and their parallel computation strategies. On the basis of it, the parallelcomputing simulation environment is also constructed. It comprehensively applies symmetric multi-processing and distributed technologies and Windows XP 64 bit system. Research on CFD has focus on the parallel computation, which can meet the practical demand for computer capacity and computing time.
this paper presents the design of a system that supports execution of HLA distributed interactive simulations in an unreliable Grid environment. the design of the architecture is based on the OGSA concept that allows ...
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ISBN:
(纸本)0769520367
this paper presents the design of a system that supports execution of HLA distributed interactive simulations in an unreliable Grid environment. the design of the architecture is based on the OGSA concept that allows for modularity and compatibility with Grid Services already being developed. First of all, we focus on the part of the system which is responsible for migration of a HLA-connected component or components of the distributed application in the Grid environment. We present a runtime support library for easily plugging HLA simulations into the Grid Services Framework. We also present the impact of execution management (namely migration) on overall system performance.
Delaunay triangulation (D-TIN) is an important graphic tool in computational geometry, which is not only widely used in many real applications, but also very significant for many spatial data mining algorithms. Howeve...
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ISBN:
(纸本)9781509041527
Delaunay triangulation (D-TIN) is an important graphic tool in computational geometry, which is not only widely used in many real applications, but also very significant for many spatial data mining algorithms. However, constructing Delaunay triangulation is time-consuming for most practical applications. distributed and parallelcomputing mechanism is becoming a good choice to solve large scale and compute-intensive D-TIN applications. this paper proposes a novel hybrid algorithm (HA) for D-TIN construction in cloud computing environment, which is based on a balanced binary-tree model and an elegant data structure called quad-edge. HA combines the divide & conquer approach and the incremental method. Moreover, a distributed and parallel version of Delaunay triangulation computing service in cloud is designed and implemented. the hybrid algorithm performed in both centralised and in cloud environments are compared. Experimental results showed that the hybrid D-TIN service outperforms boththe the divide & conquer one and the incremental one, and it can effectively provide higher data mining services with fundamental D-TIN construction function in cloud.
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