Game environments provide a good domain for serious simulations such as those used in training navy conning officers. Currently, a typical training scenario requires multiple personnel to play each of the boats and th...
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Game environments provide a good domain for serious simulations such as those used in training navy conning officers. Currently, a typical training scenario requires multiple personnel to play each of the boats and thus is expensive. We propose an approach to addressing this issue by developing intelligent, autonomous controllers for each boat. Significant challenges toward achieving these goals are the realism of behavior exhibited by the automated boats and their realtime response to change. In this paper we describe a control architecture that enables the real-time response of boats and the repertoire of realistic behaviors we developed for this application. We demonstrate the capabilities of our system with experimental results
Grid computing has emerged as an effective means of facilitating the sharing of distributed heterogeneous resources, enabling collaboration in large scale environments. However, the nature of grid systems coupled with...
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Grid computing has emerged as an effective means of facilitating the sharing of distributed heterogeneous resources, enabling collaboration in large scale environments. However, the nature of grid systems coupled with the overabundance and fragmentation of information, makes it difficult to monitor resources, services, and computations in order to plan and make decisions. In this paper we present Gridscape II, a customisable portal component that can be used on its own or plugged-in to compliment existing grid portals. Gridscape II manages the gathering of information from arbitrary, heterogeneous and distributed sources and presents them together seamlessly within a single interface. It also leverages the Google Maps API in order to provide a highly interactive user interface. Gridscape II is simple and easy to use, providing a solution to those users who do not wish to invest heavily in developing their own monitoring portal from scratch, and also for those users who want something easy to customise and extend for their specific needs
In previous years, many studies have been conducted on grid computing, in which users and resource providers organize various virtual organizations (VOs) to share resources and services. A VO organizes other sub-VOs f...
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In previous years, many studies have been conducted on grid computing, in which users and resource providers organize various virtual organizations (VOs) to share resources and services. A VO organizes other sub-VOs for the purpose of achieving the VO goal, which forms the hierarchical VO environment. In this paper, we model and formalize the resource allocation problem in hierarchical VOs. Resource providers and VOs agree upon the VO resource sharing policy, such as resource sharing amount and resource usage cost for VOs. We provide the resource allocation scheme of a VO resource broker to minimize the total cost in order to meet a user's job deadline. In addition, we deal with several cost adjustment methods in resource providers to utilize their resources efficiently in hierarchical VOs
The advent of service-oriented grid computing has resulted in the need for grid resources such as clusters to enforce user-specific service needs and expectations. Service level agreements (SLAs) define conditions whi...
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The advent of service-oriented grid computing has resulted in the need for grid resources such as clusters to enforce user-specific service needs and expectations. Service level agreements (SLAs) define conditions which a cluster needs to fulfill for various jobs. An example of SLA requirement is the deadline by which a job has to be completed. In addition, these clusters implement job admission control so that overall service performance does not deteriorate due to accepting exceeding amount of jobs. However, their effectiveness is highly dependent on accurate runtime estimates of jobs. This paper thus examines the adverse impact of inaccurate runtime estimates for deadline constrained job admission control in clusters using the earliest deadline first (EDF) strategy and a deadline-based proportional processor share strategy called Libra. Simulation results show that an enhancement called LibraRisk can manage the risk of inaccurate runtime estimates better than EDF and Libra by considering the risk of deadline delay
Over the last few years, grid technologies have progressed towards a service-oriented paradigm that enables a new way of service provisioning based on utility computing models. Users consume these services based on th...
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Over the last few years, grid technologies have progressed towards a service-oriented paradigm that enables a new way of service provisioning based on utility computing models. Users consume these services based on their QoS (quality of service) requirements. In such “pay-per-use” grids, workflow execution cost must be considered during scheduling based on users' QoS constraints. In this paper, we propose a budget constraint based scheduling, which minimizes execution time while meeting a specified budget for delivering results. A new type of genetic algorithm is developed to solve the scheduling optimization problem and we test the scheduling algorithm in a simulated grid testbed.
Data replication is one of the key components in data grid architecture as it enhances data access and reliability and minimises the cost of data transmission. In this paper, we address the problem of reducing the ove...
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ISBN:
(纸本)9781424430116
Data replication is one of the key components in data grid architecture as it enhances data access and reliability and minimises the cost of data transmission. In this paper, we address the problem of reducing the overheads of the replication mechanisms that drive the data management components of a data grid. We propose an approach that extends the resource broker with policies that factor in user quality of service as well as service costs when replicating and transferring data. A realistic model of the data grid was created to simulate and explore the performance of the proposed policy. The policy displayed an effective means of improving the performance of the grid network traffic and is indicated by the improvement of speed and cost of transfers by brokers.
The MPI-IO standard creates a huge opportunity to break out of the traditional file system I/O methods. As a software layer between the user and the file system, an MPI-IO library can potentially optimize I/O on behal...
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The MPI-IO standard creates a huge opportunity to break out of the traditional file system I/O methods. As a software layer between the user and the file system, an MPI-IO library can potentially optimize I/O on behalf of the user with little to no user intervention. This is all possible because of the rich data description and communication infrastructure MPI-2 offers. Powerful data descriptions and some of the other desirable features of MPI-2, however, make MPI-IO challenging to implement. By creating a new collective I/O implementation that allows developers to easily tinker and play with new optimizations or combinations of different techniques, research can proceed faster and be quickly and reliably deployed
Distributed computingsystems are a viable and less expensive alternative to parallel computers. However, concurrent programming methods in distributed systems have not been studied as extensively as for parallel comp...
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Distributed computingsystems are a viable and less expensive alternative to parallel computers. However, concurrent programming methods in distributed systems have not been studied as extensively as for parallel computers. Some of the main research issues are how to deal with scheduling and load balancing of such a system, which may consist of heterogeneous computers. In the past, a variety of dynamic scheduling schemes suitable for parallel loops (with independent iterations) on heterogeneous computer clusters have been obtained and studied. However, no study of dynamic schemes for loops with iteration dependencies has been reported so far. In this work we study the problem of scheduling loops with iteration dependencies for heterogeneous (dedicated and non-dedicated) clusters. The presence of iteration dependencies incurs an extra degree of difficulty and makes the development of such schemes quite a challenge. We extend three well known dynamic schemes (CSS, TSS and DTSS) by introducing synchronization points at certain intervals so that processors compute in pipelined fashion. Our scheme is called dynamic multi-phase scheduling (DMPS) and we apply it to loops with iteration dependencies. We implemented our new scheme on a network of heterogeneous computers and studied its performance. Through extensive testing on two real-life applications (the heat equation and the Floyd-Steinberg algorithm), we show that the proposed method is efficient for parallelizing nested loops with dependencies on heterogeneous systems.
IPSec provides Maturity solutions to various network based applications i.e., web applications. Implementing the, IPSec in network layer includes significant bandwidth and processing time, overhead to application traf...
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IPSec provides Maturity solutions to various network based applications i.e., web applications. Implementing the, IPSec in network layer includes significant bandwidth and processing time, overhead to application traffic. The upperlayer protocols such as TCP and UDP behaviour is also influenced by these overheads. In war work, we have studied the impact of IPSee on the metrics: Round Trip Time, Average Burst Size and Available Bandwidth for IPv4 and IPv6 network ***-MD5 authentication algorithm, advanced encryption standard encryption algorithm, and deflate comperession algorithm are used for the protocols of IPSec. From the characterized metrics and computed overheads we analyze tile impact of IPSec on connection handling capacity of web application servers by considering the user behaviour on web page requests.
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