The co-modality is a new notion introduced by the European commission in 2006. It consists on developing infrastructures and taking measures and actions that will ensure optimum combination of individual transport mod...
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ISBN:
(纸本)9781457706530
The co-modality is a new notion introduced by the European commission in 2006. It consists on developing infrastructures and taking measures and actions that will ensure optimum combination of individual transport modes enabling them to be combined effectively in terms of economic, environmental, service and financial efficiency, etc. Including different transport services in one system means that this one must cope with different distributed transport information stored in different location. For these reasons, we propose in this paper a distributed architecture that aims to satisfy transport users by providing them an optimized co-modal itineraries taking in account their constraints and preferences.
Remote live forensics has recently been increasingly used in order to facilitate rapid remote access to enterprise machines. We present the GRR Rapid Response Framework (GRR), a new multi-platform, open source tool fo...
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Remote live forensics has recently been increasingly used in order to facilitate rapid remote access to enterprise machines. We present the GRR Rapid Response Framework (GRR), a new multi-platform, open source tool for enterprise forensic investigations enabling remote raw disk and memory access. GRR is designed to be scalable, opening the door for continuous enterprise wide forensic analysis. This paper describes the architecture used by GRR and illustrates how it is used routinely to expedite enterprise forensic investigations. (C) 2011 Cohen, Bilby & Caronni. Published by Elsevier Ltd. All rights reserved.
We focus on agent-based simulations where a large number of agents move in the space, obeying to some simple rules. Since such kind of simulations are computational intensive, it is challenging, for such a contest, to...
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ISBN:
(纸本)9780769543284
We focus on agent-based simulations where a large number of agents move in the space, obeying to some simple rules. Since such kind of simulations are computational intensive, it is challenging, for such a contest, to let the number of agents to grow and to increase the quality of the simulation. A fascinating way to answer to this need is by exploiting parallel architectures. In this paper, we present a novel distributed load balancing schema for a parallel implementation of such simulations. The purpose of such schema is to achieve an high scalability. Our approach to load balancing is designed to be lightweight and totally distributed: the calculations for the balancing take place at each computational step, and influences the successive step. To the best of our knowledge, our approach is the first distributed load balancing schema in this context. We present both the design and the implementation that allowed us to perform a number of experiments, with up-to 1, 000, 000 agents. Tests show that, in spite of the fact that the load balancing algorithm is local, the workload distribution is balanced while the communication overhead is negligible.
Recently, there have been several developments in the scientific community to model and solve complex optimization problems by employing natural metaphors. In some cases, due to their distributed schema, these algorit...
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ISBN:
(纸本)9780769543284
Recently, there have been several developments in the scientific community to model and solve complex optimization problems by employing natural metaphors. In some cases, due to their distributed schema, these algorithms can be adapted to distributed computing environments. A distributed and asynchronous bees (DAB) grid-based approach is here used to optimise the magnetic configuration in order to reduce the neoclassical transport of particles in a nuclear fusion device. Large-scale problems (as several plasma physics can be classified) present open challenges that need a large computing capacity to be solved. Thus, the use of large distributed infrastructures is mandatory in many of these problems. The use of grid computing offers a new paradigm where the distributed nature of foraging can be reproduced and applied to complex optimisation problems.
In general, passenger transportation systems for urban areas utilize fixed routes and durable schedules. This paradigm works well for static environments and rather constant customer movement patterns. However, whethe...
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ISBN:
(纸本)9781424483273
In general, passenger transportation systems for urban areas utilize fixed routes and durable schedules. This paradigm works well for static environments and rather constant customer movement patterns. However, whether or not required, actual demands at busy times are often neglected or compensated by tighter schedules. Demand responsive transport services are an alternative to the static approach whereby the transport system adjusts e. g. the service frequency to current demands. In our previous work we introduced dynamic transfer nodes to leverage on-demand transportation services in terms of scalability and service quality. Thereby, vehicles exchange their current passenger lists, cluster these lists according to passenger destinations, and estimate whether an opportunity to transfer passengers between vehicles can help to reduce the overall travel time. In this paper we present an evaluation based on different city morphologies utilizing different passenger demand models. We extended our simulation environment for the application of OpenStreetMap data, appropriate routing functionality, depots, and a demand dependent dynamic fleet size.
In this paper we explore the structure and applicability of the distributed Measurement Calculus (DMC), an assembly language for distributed measurement-based quantum computations. We describe the formal language'...
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ISBN:
(纸本)3642037445
In this paper we explore the structure and applicability of the distributed Measurement Calculus (DMC), an assembly language for distributed measurement-based quantum computations. We describe the formal language's syntax and semantics, both operational and denotational, and state several properties that are crucial to the practical usability of our language, such as equivalence of our semantics, as well as compositionality and context-freeness of DMC programs. We show how to put these properties to use by constructing a composite program that implements distributed controlled operations, in the knowledge that the semantics of this program does not change under the various composition operations. Our formal model is the basis of a quantum virtual machine construction for distributed quantum computations, which we elaborate upon in the latter part of this work. This virtual machine embodies the formal semantics of DMC such that programming execution no longer needs to be analysed by hand. Far from a literal translation, it requires a substantial concretisation of the formal model at the level of data structures, naming conventions and abstraction mechanisms. At the same time we provide automatisation techniques for program specification where possible to obtain an expressive and user-friendly programming environment.
In order to meet the complicated requirements of jewelry enterprise resource management, the paper designed and implemented a distributed management information system. The system adopts a dynamic strategy to handle e...
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ISBN:
(纸本)9781457703218
In order to meet the complicated requirements of jewelry enterprise resource management, the paper designed and implemented a distributed management information system. The system adopts a dynamic strategy to handle enterprise resources sharing both horizontally and vertically, including querying, adding, deleting and modifying jewelry information, gathering statistics information, scheduling production plan. The consistency and accuracy of enterprise data are guaranteed by means of centralizing basic data and information. Web application development technology based on Java is used, and the key techniques mainly include adding information dynamically, distributed computing, and real-time information analysis, etc. Data processing mainly uses the Java Persistence API.
distributed systems comprise a significant number of entities that must be properly coordinated to reach a goal. These systems present high turnover of elements, and demand for solutions that keep their coordination a...
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ISBN:
(纸本)9780769543512
distributed systems comprise a significant number of entities that must be properly coordinated to reach a goal. These systems present high turnover of elements, and demand for solutions that keep their coordination as decentralized as possible to avoid bottlenecks. The paper discusses why it is important to address these characteristics from a system's conception and proposes A-3, an innovative architectural solution that adopts the concept of group as an abstraction for organizing an application into semi-independent slices, providing a single and coherent view of these aggregates, and coordinating the interactions inside and among groups. The paper presents the A-3 model and defines it as an innovative architectural style, describes a Java-based framework that supports A-3 and provides users with the proper means to exploit the style, and exemplifies all the main concepts on a simple scenario where autonomous robotic vacuum cleaners are coordinated to properly clean a museum.
Large-scale e-science applications feature complex work-flows consisting of many computing modules. Mapping such workflows in distributed network environments and minimizing their latency are crucial to those applicat...
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ISBN:
(纸本)9781617828362
Large-scale e-science applications feature complex work-flows consisting of many computing modules. Mapping such workflows in distributed network environments and minimizing their latency are crucial to those applications that require fast system response and prompt user interaction. We model the time cost of each workflow component and design an efficient algorithm to compute the exact end-to-end delay of the entire workflow by explicitly accounting for the resource sharing dynamics. We further propose a workflow mapping approach to minimize the workflow latency using a recursive optimization procedure. The validity of the cost models and the accuracy of the latency computing algorithm are verified in comparison with an approximate solution, a dynamic system simulation program, and a workflow engine deployed in a real network. The performance superiority of the proposed mapping approach is illustrated by extensive simulation-based comparisons with existing algorithms.
Modern tracking and fusion settings involve multiple platforms in different locations, tracking different target tracks, focusing on different regions of interest, while using different update rates and sensor resolut...
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ISBN:
(纸本)9780819486240
Modern tracking and fusion settings involve multiple platforms in different locations, tracking different target tracks, focusing on different regions of interest, while using different update rates and sensor resolutions with the goal of providing increased situation awareness in the region by fusing together the diversity of information from each platform. In this paper, a decentralized, distributed fusion architecture is presented along with results and trade studies comparing performance to that of a centralized fusion architecture. The decentralized distributed architecture is designed to work with legacy tracking systems and uses an efficient message passing scheme to share information and coordinate tracks across a diverse group of platforms. This system does not rely on a central node and allows for track information to be maintained at the local level while utilizing track information from other platforms to increase situation awareness. We compare the performance between our distributed approach and a centralized system using simulated airborne sensors operating in overlapping regions of interest with target densities and routes chosen to demonstrate tradeoffs between the different architectures. Preliminary results show that the decentralized distributed system provides similar performance to the centralized fusion system in terms of situation awareness relative to traditional tracking metrics, but at the cost of using an increased communication bandwidth to provide frequent updates to neighboring platforms. Results demonstrate the tradeoff between flexibility and optimality - configuration of the distributed decentralized system to provide increased flexibility and robustness comes at the cost of reduced situation awareness as compared to the centralized system.
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