检索结果-南通市图书馆

Observable liveness of Petri nets with controllable and observable transitions

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2017年第11期60卷 256-264页

作者： Guanjun LIU Changjun JIANG Department of Computer Science Tongji University Key Laboratory of Embedded System and Service computing of Ministry of Education Tongji University E-commerce transactions and Information services Collaborative Innovation Center of Shanghai University Knowledge Service Platform Tongji University

Observability and/or controllability are paid much attention to by researchers not only from the control science field[1–3]but also from the computer science field[4–9].Recently,Desel and Kilinc[4]proposed the notion of observable liveness for Petri nets with(un-)observable and(un-)controllable *** purpose of defining observable liveness is to represent that"a user can always enforce the occurrence of any observable transition only by stimulating the net by choosing appropriate enabled controllable transition"[4].An important assumption of

关键词： net cot PN Observable liveness of Petri nets with controllable and observable transitions

MOBILE INFORMATION SYSTEMS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国通信：英文版 2015年第12期12卷 I0002-I0003页

作者： WANG Shangguang Ching-Hsien Hsu David Taniar Patrick Hung Beijing University of Posts and Telecommunications department of computer science and information engineering at Chung Hua University Taiwan China the Faculty of Information Technology Monash UniversityAustralia University of Ontario Institute of Technology Canada the ieee transactions on services computing International Journal of Web Services Research and International Journal of Business Process and Integration Management the Information Systems Frontiers by Springer

With the popularity of mobile infrastructures providing higher bandwidth and constant connection to the network from virtually anytime and everywhere,the way people use information resources is radically *** can use mobile devices such as mobile phones,pocket PCs,laptops,etc.,to obtain services/applications which are based on the mobile

关键词：移动信息系统管理信息系统信息资源笔记本电脑基础设施移动设备掌上电脑应用程序

Application-Aware Client-Side Data Reduction and Encryption of Personal Data in Cloud Backup services

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2013年第6期28卷 1012-1024页

作者：付印金肖侬廖湘科刘芳 State Key Laboratory of High Performance computing National University of Defense Technology ieee School of Computer National University of Defense Technology CCF

Cloud backup has been an important issue ever since large quantities of valuable data have been stored on the personal computing devices. Data reduction techniques, such as deduplication, delta encoding, and Lempel-Ziv （LZ） compression, performed at the client side before data transfer can help ease cloud backup by saving network bandwidth and reducing cloud storage space. However, client-side data reduction in cloud backup services faces efficiency and privacy challenges. In this paper, we present Pangolin, a secure and efficient cloud backup service for personal data storage by exploiting application awareness. It can speedup backup operations by application-aware client-side data reduction technique, and mitigate data security risks by integrating selective encryption into data reduction for sensitive applications. Our experimental evaluation, based on a prototype implementation, shows that our scheme can improve data reduction efficiency over the state-of-the-art methods by shortening the backup window size to 33%-75%, and its security mechanism for＇ sensitive applications has negligible impact on backup window size.

关键词： cloud backup data reduction application awareness selective encryption

A Dynamic Road Incident Information Delivery Strategy to Reduce Urban Traffic Congestion

在线全文

学校读者我要写书评

暂无评论

ieee/CAA Journal of Automatica Sinica 2018年第5期5卷 934-945页

作者： Liang Qi Mengchu Zhou Wenjing Luan ieee Department of Computer Scicnce and Technology Shandong University of Science and TechnologyQingdao 266590China Department of Computer Science Tongji UniversityShanghai 201804China Department of Electrical and Computer Engineering New Jersey Institute of TechnologyNewark NJ 07102USA Key Laboratory of Embedded System and Service computing Ministry of EducationShanghai Electronic Transactions and Information Service Collaborative Innovation CenterDepartment of Com-puter ScienceTongji UniversityShanghai 201804China

Advanced information and communication technolo-gies can be used to facilitate traffic incident *** an incident is detected and blocks a road link,in order to reduce the incident-induced traffic congestion,a dynamic strategy to deliver incident information to selected drivers and help them make detours in urban areas is proposed by this ***-dependent shortest path algorithms are used to generate a subnetwork where vehicles should receive such information.A simulation approach based on an extended cell transmission model is used to describe traffic flow in urban networks where path information and traffic flow at downstream road links are well *** results reveal the influences of some major parameters of an incident-induced congestion dissipation process such as the ratio of route-changing vehicles to the total vehicles,operation time interval of the proposed strategy,traffic density in the traffic network,and the scope of the area where traffic incident information is *** results can be used to improve the state of the art in preventing urban road traffic congestion caused by incidents.

关键词： Cell transmission model(CTM) intelligent transportation systems(ITS) traffic incident management(TIM) urban traffic congestion

UAV-Assisted Dynamic Avatar Task Migration for Vehicular Metaverse services: A Multi-Agent Deep Reinforcement Learning Approach

在线全文

学校读者我要写书评

暂无评论

ieee/CAA Journal of Automatica Sinica 2024年第2期11卷 430-445页

作者： Jiawen Kang Junlong Chen Minrui Xu Zehui Xiong Yutao Jiao Luchao Han Dusit Niyato Yongju Tong Shengli Xie ieee School of Automation Guangdong University of TechnologyGuangzhou 510006China 111 Center for Intelligent Batch Manufacturing based on IoT Technology Guangzhou 510006China Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China School of Computer Science and Engineering Nanyang Technological UniversitySingaporeSingapore Pillar of Information Systems Technology and Design Singapore University of Technology and DesignSingaporeSingapore College of Communication Engineering Army Engineering University of PLANanjing 210007China National Natural Science Foundation of China Beijing 100085China Key Laboratory of Intelligent Detection and IoT in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangzhou 510006China

Avatars, as promising digital representations and service assistants of users in Metaverses, can enable drivers and passengers to immerse themselves in 3D virtual services and spaces of UAV-assisted vehicular Metaverses. However, avatar tasks include a multitude of human-to-avatar and avatar-to-avatar interactive applications, e.g., augmented reality navigation,which consumes intensive computing resources. It is inefficient and impractical for vehicles to process avatar tasks locally. Fortunately, migrating avatar tasks to the nearest roadside units(RSU)or unmanned aerial vehicles(UAV) for execution is a promising solution to decrease computation overhead and reduce task processing latency, while the high mobility of vehicles brings challenges for vehicles to independently perform avatar migration decisions depending on current and future vehicle status. To address these challenges, in this paper, we propose a novel avatar task migration system based on multi-agent deep reinforcement learning(MADRL) to execute immersive vehicular avatar tasks dynamically. Specifically, we first formulate the problem of avatar task migration from vehicles to RSUs/UAVs as a partially observable Markov decision process that can be solved by MADRL algorithms. We then design the multi-agent proximal policy optimization(MAPPO) approach as the MADRL algorithm for the avatar task migration problem. To overcome slow convergence resulting from the curse of dimensionality and non-stationary issues caused by shared parameters in MAPPO, we further propose a transformer-based MAPPO approach via sequential decision-making models for the efficient representation of relationships among agents. Finally, to motivate terrestrial or non-terrestrial edge servers(e.g., RSUs or UAVs) to share computation resources and ensure traceability of the sharing records, we apply smart contracts and blockchain technologies to achieve secure sharing management. Numerical results demonstrate that the proposed approach

关键词： Avatar blockchain metaverses multi-agent deep reinforcement learning transformer UAVs

MSIT 2012 Keynote Speech Bargaining as a Cloud Pricing Model

在线全文

学校读者我要写书评

暂无评论

MSIT 2012 Keynote Speech Bargaining as a Cloud Pricing Model

Autonomic Performance and Power Control on Virtualized Servers:Survey, Practices, and Trends

2012 International Conference on Management Sciences and Information Technology(MSIT 2012)

作者： Ben Kwang Mong Sim University of Kent Chatham MaritimeKentUnited Kingdom ieee transactions on Systems Man ＆ Cybernetics （IEEE Press）

Devising an effective pricing model is one of the challenging issues in Clouds computing. Existing Cloud service providers provide consumers with both fixed pricing（e.g., Amazon EC2’s on‐demand instances and reserved instances） and flexible pricing（e.g., Amazon EC2’s spot instances） for leasing virtual machine instances. Even though spot instances enable consumers to save cost in some situations through flexible pricing（depending on the supply and demand of computing resources）, consumers’ applications running on spot instances can potentially be interrupted. The first part of this talk will present a negotiation（bargaining） mechanism that 1) enables consumers to establish contracts with providers to guarantee that they can run their applications at reserved time slots without interruption and 2) allows providers to schedule resources to meet consumers’ requests at nonpeak time to reduce resource idle time. An overview of the components of the negotiation mechanism consisting of negotiation agents and their negotiation strategies and protocols will be presented. The proofs of the optimality of the negotiation strategies, and empirical results comparing this work with a related negotiation mechanism together with a case study comparing the negotiation mechanism with pricing models of Amazon’s EC2 will also be presented. Supporting autonomous resource mapping and dealing with changing requests accentuate the need for software agents that are capable of continuously managing the resource reservation process by autonomously adjusting resource schedules and prices to accommodate dynamically changing resource demands. The second part of this talk will present the idea of an agent‐based "Cloud commerce" model.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2014年第4期29卷 631-645页

作者：周笑波蒋昌俊 ieee ACM Department of Computer Science University of Colorado Colorado Springs U.S.A. The Key Laboratory of Embedded System and Service computing Ministry of Education Tongji University CCF Department of Computer Science and Technology Tongji University

Modern datacenter servers hosting popular Internet services face significant and multi-facet challenges in performance and power control. The user-perceived performance is the result of a complex interaction of complex workloads in a very complex underlying system. Highly dynamic and bursty workloads of Internet services fluctuate over multiple time scales, which has a significant impact on processing and power demands of datacenter servers. High-density servers apply virtualization technology for capacity planning and system manageability. Such virtuMized computer systems are increasingly large and complex. This paper surveys representative approaches to autonomic performance and power control on virtualized servers, which control the quality of service provided by virtualized resources, improve the energy efficiency of the underlying system, and reduce the burden of complex system management from human operators. It then presents three designed self-adaptive resource management techniques based on machine learning and control for percentile-based response time assurance, non-intrusive energy-efficient performance isolation, and joint performance and power guarantee on virtualized servers. The techniques were implemented and evaluated in a testbed of virtualized servers hosting benchmark applications. Finally, two research trends are identified and discussed for sustainable cloud computing in green datacenters.

关键词： autonomic computing joint performance and power control virtualized server Internet application sustainable computing

Improving Scalability of Cloud Monitoring Through PCA-Based Clustering of Virtual Machines

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2014年第1期29卷 38-52页

作者： Claudia Canali Riccardo Lancellotti ieee Department of Information Engineering University of Modena and Reggio Emilia ACM

Cloud computing has recently emerged as a leading paradigm to allow customers to run their applications in virtualized large-scale data centers. Existing solutions for monitoring and management of these infrastructures consider virtual machines （VMs） as independent entities with their own characteristics. However, these approaches suffer from scalability issues due to the increasing number of VMs in modern cloud data centers. We claim that scalability issues can bc addressed by leveraging the similarity among VMs behavior in terms of resource usage patterns. In this paper we propose an automated methodology to cluster VMs starting from the usage of multiple resources, assuming no knowledge of the services executed on them. The innovative contribution of the proposed methodology is the use of the statistical technique known as principal component analysis （PCA） to automatically select the most relevant information to cluster similar VMs. We apply the methodology to two case studies, a virtualized testbed and a real enterprise data center. In both case studies, the automatic data selection based on PCA allows us to achieve high performance, with a percentage of correctly clustered VMs between 80% and 100% even for short time series （1 day） of monitored data. Furthermore, we estimate the potential reduction in the amount of collected data to demonstrate how our proposal may address the scalability issues related to monitoring and management in cloud computing data centers.

关键词： cloud computing resource monitoring principal component analysis k-means clustering

Dynamic I/O-Aware Scheduling for Batch-Mode Applications on Chip Multiprocessor Systems of Cluster Platforms

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2014年第1期29卷 21-37页

作者：吕方崔慧敏王蕾刘磊武成岗冯晓兵游本中 State Key Laboratory of Computer Architecture Institute of Computing Technology Chinese Academy of Sciences University of Chinese Academy of Sciences CCF ACM ieee Department of Computer Science and Engineering University of Minnesota at Twin Cities Institute of Information Science Academia Sinica

Efficiency of batch processing is becoming increasingly important for many modern commercial service centers, e.g., clusters and cloud computing datacenters. However, periodical resource contentions have become the major performance obstacles for concurrently running applications on mainstream CMP servers. I/O contention is such a kind of obstacle, which may impede both the co-running performance of batch jobs and the system throughput seriously. In this paper, a dynamic I/O-aware scheduling algorithm is proposed to lower the impacts of I/O contention and to enhance the co-running performance in batch processing. We set up our environment on an 8-socket, 64-core server in Dawning Linux Cluster. Fifteen workloads ranging from 8 jobs to 256 jobs are evaluated. Our experimental results show significant improvements on the throughputs of the workloads, which range from 7% to 431%. Meanwhile, noticeable improvements on the slowdown of workloads and the average runtime for each job can be achieved. These results show that a well-tuned dynamic I/O-aware scheduler is beneficial for batch-mode services. It can also enhance the resource utilization via throughput improvement on modern service platforms.

关键词： chip multiprocessor batch processing co-running I/0 contention scheduling