The rapid increase in performance of mass market commodity microprocessors and significant disparity in pricing between PCs and scientific workstations has provided an opportunity for substantial gains in performance ...
详细信息
The rapid increase in performance of mass market commodity microprocessors and significant disparity in pricing between PCs and scientific workstations has provided an opportunity for substantial gains in performance to cost by harnessing PC technology in parallel ensembles to provide high end capability for scientific and engineering applications. The Beowulf project is a NASA initiative sponsored by the HPCC program to explore the potential of Pile-of-PCs and to develop the necessary methodologies to apply these low cost system configurations to NASA computational requirements in the Earth and space sciences. This paper describes the technologies and methodologies employed to achieve the increased performance of PCs. Both opportunities afforded by this approach and the challenges confronting its application to real-world problems are discussed in the framework of hardware and software systems as well as the results from benchmarking experiments. Finally, near term technology trends and future directions of the Pile-of-PCs concept are considered.
Over the last few years there has been a phenomenal growth in the use of WWW (World Wide Web) for a wide variety of purposes from advertising and publicity, to collaborative work and teaching. Because it is so easy to...
详细信息
Many space robotic systems would be required to operate in uncertain or even unknown environments. In the paper, the problem of identifying such environments for compliance control is considered. In particular, neural...
详细信息
Many space robotic systems would be required to operate in uncertain or even unknown environments. In the paper, the problem of identifying such environments for compliance control is considered. In particular, neural networks are used for identifying environments that a robot establishes contact with. Both function approximation and parameter identification (with fixed nonlinear structure and unknown parameters) results are presented. The environment model structure considered is relevant to two space applications: cooperative execution of tasks by robots and astronauts, and sample acquisition during planetary exploration. Compliant motion experiments have been performed with a robotic arm, placed in contact with a single degree-of-freedom electromechanical environment. In the experiments, desired contact forces are computed using a neural network, given a desired motion trajectory. Results of the control experiments performed on robot hardware are described, along with relevant discussions.
Many robotic systems would, in the future, be required to operate in environments that are highly uncertain and possessing means of self-actuation. In this paper, the problem of identifying uncertain environments for ...
详细信息
Many robotic systems would, in the future, be required to operate in environments that are highly uncertain and possessing means of self-actuation. In this paper, the problem of identifying uncertain environments for stable contact control is considered. In particular, system parameters are identified under the assumption that environment dynamics have a fixed nonlinear structure. A robotics research arm, placed in contact with a single dof electromechanical environment dynamics emulator, is commanded to move through a desired trajectory. The command is implemented using a compliant control strategy.
This book comprises selected papers of the International Conferences, CA and CES3 2011, held as Part of the Future Generation information Technology Conference, FGIT 2011, in Conjunction with GDC 2011, Jeju Island, Ko...
详细信息
ISBN:
(数字)9783642260100
ISBN:
(纸本)9783642260094
This book comprises selected papers of the International Conferences, CA and CES3 2011, held as Part of the Future Generation information Technology Conference, FGIT 2011, in Conjunction with GDC 2011, Jeju Island, Korea, in December 2011.
The papers presented were carefully reviewed and selected from numerous submissions and focuse on the various aspects of control and automation, and circuits, control, communication, electricity, electronics, energy, system, signal and simulation.
Connected Autonomous Vehicle (CAV) Driving, as a data-driven intelligent driving technology within the Internet of Vehicles (IoV), presents significant challenges to the efficiency and security of real-time data manag...
详细信息
Connected Autonomous Vehicle (CAV) Driving, as a data-driven intelligent driving technology within the Internet of Vehicles (IoV), presents significant challenges to the efficiency and security of real-time data management. The combination of Web3.0 and edge content caching holds promise in providing low-latency data access for CAVs’ real-time applications. Web3.0 enables the reliable pre-migration of frequently requested content from content providers to edge nodes. However, identifying optimal edge node peers for joint content caching and replacement remains challenging due to the dynamic nature of traffic flow in IoV. Addressing these challenges, this article introduces GAMA-Cache, an innovative edge content caching methodology leveraging Graph Attention Networks (GAT) and Multi-Agent Reinforcement Learning (MARL). GAMA-Cache conceptualizes the cooperative edge content caching issue as a constrained Markov decision process. It employs a MARL technique predicated on cooperation effectiveness to discern optimal caching decisions, with GAT augmenting information extracted from adjacent nodes. A distinct collaborator selection mechanism is also developed to streamline communication between agents, filtering out those with minimal correlations in the vector input to the policy network. Experimental results demonstrate that, in terms of service latency and delivery failure, the GAMA-Cache outperforms other state-of-the-art MARL solutions for edge content caching in IoV.
The beginning of the twenty-first century is characterized by global markets, and the mobility of people is becoming an important fact of life. Consequently, the mobile user is demanding appropriate technical solution...
详细信息
ISBN:
(数字)9783540320319
ISBN:
(纸本)9783540294108
The beginning of the twenty-first century is characterized by global markets, and the mobility of people is becoming an important fact of life. Consequently, the mobile user is demanding appropriate technical solutions to make use of customized information and communication services. In this context the notion of next-generation networks (NGNs), which are driven by the convergence of the entertainment sector, the mobile Internet, and fixed/mobile telecommunications, is emerging. Such NGNs are aggregating a variety of different access networks and supporting the seamless connection of an open set of end-user devices, and due to the adoption of an all-IP network paradigm they enable a much better integration of voice and data services. Coincidently the buzzword ‘fixed mobile convergence’ (FMC) describes the current trend towards providing common services across fixed and mobile networks resulting in the medium term in the full integration of fixed and mobile telecommunication networks. The adoption of appropriate middleware technologies and the provision of - called service delivery platforms driven by the ongoing innovation in the field of information technologies provides today the technical foundation for supporting terminal, personal and service mobility and thus the implementation of real seamless information and communication services. Furthermore, users are nowadays looking, in light of an omnipresent service environment, for a much higher degree of customization and context awareness in the services they use. The papers in this volume look at these enabling mobility-aware technologies and their use for implementing mobility-aware and context-aware applications.
暂无评论