the planning and the design of the electrical supply system are everyday tasks for engineers in the electric utilities. the goal of power distribution system planning is to satisfy the growing and changing system load...
详细信息
the planning and the design of the electrical supply system are everyday tasks for engineers in the electric utilities. the goal of power distribution system planning is to satisfy the growing and changing system load demand during the planning period and within operational constraints, with minimal costs. this paper presents computer Aided Design of Distribution Network application (CADDiN) based on geographic information system (GIS) and genetic algorithms (GA). the application has shown success in solving the distribution system planning problem of optimization of loop and link structured urban distribution networks.
In many communication systems we may assume that every node is directly connected to every other node. It does not matter whether the system is a massively parallel computer where each processor is a node and the conn...
详细信息
In many communication systems we may assume that every node is directly connected to every other node. It does not matter whether the system is a massively parallel computer where each processor is a node and the connectivity is achieved using a software communication library or if the system is the Internet where each node is a computer and the connectivity is achieved using IP. the postal model started withthis assumption and in addition assumed that the process of delivering a message between two nodes takes a constant amount of time called the communication delay (greater than one unit of time), and that when a node sends a message or receives a message it wastes a single time unit. In this paper, we enhanced the postal model by removing the assumption that the communication delay is constant. Without this constraint. the broadcasting problem is NP-complete and therefore we study two directions. (i) We present heuristic algorithms and analyze them. (ii) We evaluate simple topologies of networks (by assuming large delays when there is not a direct connection). We have also tested the heuristic algorithms with simulations and compared them to the optimal solutions.
In this paper, nonlinear prediction of speech is performed by using a radial basis function (RBF) network. the RBF network has the parameters: (1) dimension of the input vector; (2) number of hidden nodes; (3) basis f...
详细信息
In this paper, nonlinear prediction of speech is performed by using a radial basis function (RBF) network. the RBF network has the parameters: (1) dimension of the input vector; (2) number of hidden nodes; (3) basis function; (4) centers; (5) widths and (6) weights to be selected. the complexity and the performance heavily depend on the input dimension and the number of centers. Reduction of complexity while maintaining the performance by decreasing both is still an open problem. the hierarchically self-organizing algorithm, which automatically adjusts the number of centers, with a dynamical systems approach is suggested as a solution. this algorithm is compared to standard approaches vis extensive computer simulations.
the problem of constructing a nonlinear controller for a biped robot optimal with respect to a minimal energy performance criteria is considered. the solution of this difficult, highly nonlinear problem is facilitated...
详细信息
the problem of constructing a nonlinear controller for a biped robot optimal with respect to a minimal energy performance criteria is considered. the solution of this difficult, highly nonlinear problem is facilitated by the conjunction of several new developments in numerical optimal control and constrained recursive dynamic models for robotic systems. A 5-link biped model is used withthe full dynamics and a uniform distribution of mass at each link. Contacts are modeled as inelastic, and the full dynamics together withthe contact and collision forces are calculated efficiently using a recursive symbolic representation of the dynamics. the flexibility and modularity of our dynamics algorithms allows one to construct reduced unconstrained models which do not suffer from integration difficulties. the numerical optimal control software used is powerful and quick enough to handle high dimensional nonlinear systems. the result of our experiment is a walking controller which is optimal with respect to a type of minimum energy performance.
A command and control application developed at IET has recently gone a major architectural change, to use a blackboard framework. As opposed to many blackboard-based applications, in which the blackboard model is used...
详细信息
ISBN:
(纸本)0818681365
A command and control application developed at IET has recently gone a major architectural change, to use a blackboard framework. As opposed to many blackboard-based applications, in which the blackboard model is used to model only the top level of the application, we developed a blackboard framework that fractal-like: the blackboard paradigm serves as the abstraction for all levels, recursively. We have also achieved maximal separation among the different blackboard-based elements at the various levels. this implies having small disconnected components which are flexible and reusable, and which together form the application. In this paper we present our fractal blackboard framework, and discuss interesting issues related to its design and usage.
In distributed redundant-resource systems such as communication networks with multiple paths between nodes, there is a choice in allocating resources to tasks;this can be used for fault-tolerance, but also in order to...
详细信息
ISBN:
(纸本)0818681365
In distributed redundant-resource systems such as communication networks with multiple paths between nodes, there is a choice in allocating resources to tasks;this can be used for fault-tolerance, but also in order to improve performance. the allocation, however is complicated by the fact that system state is not known and changes dynamically. Exploiting redundancy by partitioning a message into several submessages and sending them along with several ''redundant'' submessages along different paths, as is done by dispersal schemes, increases the load, reduces capacity and even increases delay at permissible heavy loads. We present and analyze novel ''prioritized dispersal'' schemes, whereby ''redundant'' submessages receive lower priority than the ''original'' submessages, and show their performance to substantially exceed that of non-prioritized schemes. this extends the beneficial applicability of selective exploitation of redundancy, whose benefits for centralized systems have been established, to distributed systems.
Iterative control constructs in data flow programming languages have always been a challenging part of language design. We suggest a solution for iterative processing in data flow diagrams based on the notion of a con...
详细信息
ISBN:
(纸本)0818681365
Iterative control constructs in data flow programming languages have always been a challenging part of language design. We suggest a solution for iterative processing in data flow diagrams based on the notion of a conditional data flow switch, and a specialized iterative constructs based on pattern matching for vectors, matrices, and multisets. All of these constructs can be seamlessly incorporated into a data flow visual programming language. We demonstrate how these constructs may be used to reveal the spatial/temporal dualism of data streams.
Resource scheduling in distributed systems aims at achieving maximal system performance by utilizing the available system resources efficiently. Large distributed systems, comprising hundreds or thousands of nodes and...
详细信息
ISBN:
(纸本)0818681365
Resource scheduling in distributed systems aims at achieving maximal system performance by utilizing the available system resources efficiently. Large distributed systems, comprising hundreds or thousands of nodes and spanning vast geographical distances (e.g. Internet), require resource scheduling to be scalable. Scalability has become a common requirement in the design and development of distributed software. this paper describes a comprehensive approach to software development, leading from the stage of requirements specification, through design and algorithm assessment to a prototype implementation of a scalable resource scheduling policy. Scalability is achieved by system partitioning. Communication delays may limit scalability and degrade system performance. In this work, delays are handled to improve the performance of a scheduling policy. the paper demonstrates performance results obtained in simulation under communication and computation overload conditions. the simulation code is later used for prototype implementation. Finally, we examine the software design issues and applicability of the prototype to different distributed environments, providing the example of PVM [7].
the proceedings contains 32 papers. Topics discussed include algorithms for parallelization, distributed computersystems and networking, software tools and environments, parallel finite and boundary elements, applica...
详细信息
the proceedings contains 32 papers. Topics discussed include algorithms for parallelization, distributed computersystems and networking, software tools and environments, parallel finite and boundary elements, applications in fluid flour and applications in applied science.
暂无评论