检索结果-南通市图书馆

A novel anti-detection criterion for covert storage channel threat estimation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2018年第4期61卷 212-214页

作者： Chong WANG changyou zhang Bin WU Yu'an TAN Yongji WANG University of Chinese Academy of Sciences Cooperative Innovation Center Institute of Software Chinese Academy of Sciences State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Laboratory of Parallel Software and Computational Science Institute of Software Chinese Academy of Sciences

Covert(storage)channels[1]are widely considered a main threat[2]to multilevel secure systems,e.g.,desktop operating *** estimation,as an important part of covert channel analysis,must be included in the security analy... 详细信息

关键词： Linux

A High-Performance Hierarchical Snapshot Scheme for Hybrid Storage 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

Chinese Journal of Electronics 2018年第1期27卷 76-85页

作者： YU Xiao TAN Yu'an zhang changyou LIANG Chen Khaled AOURRA ZHENG Jun zhang Quanxin School of Computer Science and Technology Beijing Institute of Technology Department of Computer Science and Technology Shandong University of Technology Institute of Software Chinese Academy of Science

With the increased snapshot operations(creation or deletion), the performance of storage system will degrade severely whether in Copy on write(COW)or Redirect on write(ROW). This paper presents a novel snapshot scheme which could use of storage resources effectively and keep the historical data accurately for SSDHDD-hybrid storage system. SSD(source volume) stores all the active data and executes read/write operations without responding to snapshot operations. In contrast,HDDs(snapshot volume) store the writing data sequentially in the form of logs and are responsible for backup and snapshot operations. In this way, the hybrid storage system can get the high throughput power via SSD even the snapshot functions are active and HDDs can keep pace with the high Input/Output operations per second(IOPS)capability of the SSD. Logs are combined and kept in a separate image volume by the controller. So, fine-grained Recovery point objective(RPO) and good Recovery time objective(RTO) can be achieved. Experiment results show that the prototype can achieve excellent I/O performance while snapshot operations are active and consume a few extra storage space.

关键词： Hybrid disk array Snapshot Copy on write(COW) Redirect on write(ROW) Recovery point objective(RPO) Recovery time objective(RTO)

Energy-Aware GPU Programming at Source-Code Levels

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2012年第3期17卷 278-286页

作者： changyou zhang Kun Huang Xiang Cui Yifeng Chen Key Laboratory of High Confidence Software Technologies(Peking University)School of Electronics Engineering and Computer Science Peking UniversityBeijing 100871China

To enhance the energy efficiency and performance of algorithms with Graphics Processing Unit （GPU） accelerators in source-code development, we consider the power efficiency based on data transfer bandwidth and power consumption in key situations. First, a set of primitives is abstracted from program statements. Then, data transfer bandwidth and power consumption in different granularity sizes are consid- ered and mapped into proper primitives. With these mappings, a programmer can intuitively determine the power efficiency and performance in different running states of a thread. Finally, this intuition enables the programmer to tune the algorithm in order to achieve the best energy efficiency and performance. Using these power-aware principles, two Fast Fourier Transform （FFT） methods are compared. The mapping be- tween power consumption and primitives is helpful for algorithm tuning in source-code levels.

关键词： GPU power-aware source-code primitive

Boosting performance of virtualized desktop infrastructure with physical GPU and SPICE

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2020年第7期63卷 236-238页

作者： Shupan LI Limin XIAO Chungang SHI Liequan CHE changyou zhang Yuanzhang LI State Key Laboratory of Software Development Environment Beihang University School of Computer Science and Engineering Beihang University Beijing Jinghang Computation and Communication Research Institute Institute of Software Chinese Academy of Sciences School of Computer Science and Technology Beijing Institute of Technology

Dear editor,The virtual desktop infrastructure (VDI) is widely used by enterprises, as it can be easily deployed,has a reduced management cost, improves resource utilization, and can be accessed at any location by the network. Currently, there is a demand for the VDIs to support applications, such as playing 3D games, playing HD videos, and using 3D design-

关键词： visualized desktop infrastructure SPICE physical GPU The virtual machine (VM) virtual machine monitor (VMM)

A UNIFIED APPROXIMATE FEEDBACK SOLUTION OF COPLANAR VARIABLE-SPEED INTERCEPTION GAMES

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 1991年第1期6卷 11-19页

作者： Liu changyou and zhang SiyingNortheast University of Technology

In this paper, the problem of coplanar variable-speed interception between a tactical missile and an aircraft is analysed by using the differential games theory. A unified approximate guidance law in feedback form is obtained by using the technique of forced singular perturbation (FSPT). The illustrative example with the realistic aerodynamic and propulsion data shows that this suboptimal guidance control law is available for the practical applications.

关键词： A UNIFIED APPROXIMATE FEEDBACK SOLUTION OF COPLANAR VARIABLE-SPEED INTERCEPTION GAMES

Immune Recognition Method Based on Analogy Reasoning in Intrusion Detection System

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2006年第6期11卷 1839-1843页

作者： zhang changyou CAO Yuanda YANG Minghua YU Jiong ZHU Dongfeng School of Computer Science and Technology Beijing Institute of Technology Beijing 100081 China Computer Science and Technology Department Shijiazhuang Railway Institute Shijiazhuang 050043 Hebei China College of Information University Wulumuqi 830046 Science and Engineering Xinjiang Xinjiang China

In this paper, we propose an analogy based immune recognition method that focuses on the implement of the clone selection process and the negative selection process by means of analogy similarity. This method is applied in an IDS （Intrusion Detection System） following several steps. Firstly, the initial abnormal behaviours sample set is optimized through the combining of the AIS （Artificial Immune System） and the genetic algorithm. Then, the abnormity probability algorithm is raised considering the two sides of abnormality and normality. Finally, an intrusion detection system model is established based on the above algorithms and models.

关键词： immune recognition analogy reasoning similarity genetic algorithm intrusion detection system

ISS:Efficient Search Scheme Based on Immune Method in Modern Unstructured Peer-to-Peer Networks

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2007年第5期12卷 866-870页

作者： GUAN Zhitao CAO Yuanda ZHU Liehuang zhang changyou FAN Xiumei School of Computer Science and Technology Beijing Institute of Technology Beijing 100081 China

Flooding is the most famous technique for locating contents in unstructured P2P networks. Recently traditional flooding has been replaced by more efficient dynamic query （DQ） and different variants of such algorithms. Dynamic query is a new flooding technique which could estimate a proper time-to-live （TTL） value for a query flooding by estimating the popularity of the searched files, and retrieve sufficient results under controlled flooding range for reducing network traffic. However, all DQ-like search algorithms are ＂blind＂ so that a large amount of redundant messages are caused. In this paper, we proposed a new search scheme, called Immune Search Scheme （ISS）, to cope with this problem. In ISS, an immune systems inspired concept of similarity-governed clone proliferation and mutation for query message movement is applied. Some assistant strategies, that is, shortcuts creation and peer traveling are incorporated into ISS to develop ＂immune memory＂ for improving search performance, which can make ISS not be blind but heuristic.

关键词： peer-to-peer dynamic query immune method clone proliferation and mutation

Performance Evaluation of Service Orchestration with Dynarric Latency Simulation

在线全文

学校读者我要写书评

暂无评论

China Communications 2012年第12期9卷 68-79页

作者： zhang changyou Zhu Dongfeng Hu Jingjing Jin Haifei Laboratory of Parallel Software and Computational Science Institute of Sottware Chinese Academy of Science Beijing 100190 P. R. China HOST Key Laboratory School of Electrical Engineering and Computer Science Peking University Beijing 100085 P. R. China School of Computer Beijing Institute of Technology Beijing 100081 P. R. China School of Computer Beijing University of Posts and Telecommunications Beijing 100082 P. R. China

Dynamic latency over the Intemet is an Important parameter for evaluating the performance of Web service orchestration. In this paper, we propose a performance analyzing and correctness checking method for service orchestration with dynamic latency simulated in Colored PetriNets （CPNs）. First, we extend the CPN to Web Service Composition Orchestration Network System （WS-CONS） for the description of dynamic latency in service orchestration. Secondly, with simulated dynamic latency, a buffer-limited policy and admittance-control policy are designed in WS- CONS and implemented on CPN Tools. In the buffer-limited policy, the passing messages would be discarded if the node capacity is not adequate. In the admittance-control policy, the ability of a message entering the system depends on the number of messages concurrently flowing in the system. This helps to enhance the success rate of message passing. Finally, the system performance is evaluated through running models in CPN Tools. Simulated results show that the dynamic latency plays an important role in the system throughput and response latency. This simulation helps system designers to quickly make proper compromises at low cost.

关键词： service orchestration CPN dynamic latency simulation

Self-Organizing Mechanism for Cloud Services and Performance Analysis

在线全文

学校读者我要写书评

暂无评论

China Communications 2012年第6期9卷 135-144页

作者： zhang changyou Shao Lixiang Li Wenqing Li Hangtong Chen Sicong School of Information Science and Technology Shijiazhuang Tiedao University Shijiazhuang 050043 P. R. China School of Computer Science and Technology Beijing Institute of Technology Beijing 100081 P. R. China School of Computer Beijing University of Posts and Telecommunications Beijing 100876 P. R. China

To improve the performance and robustness in service discovery, a self-organizing mechanism for service alliances of Service Providers (SPs) is proposed in this paper. According to the similarity of service content, an SP publishes its services in a partition of SPs to construct connections between highly similar SPs. These SPs constitute a self-organized distributed environment. A self-organizing protocol is designed to ensure the correctness of the construction of the alliances. The protocol consists of four stages - initiating stage, developing stage, developed stage and degradation stage. The experimental results demonstrate that this protocol ensures the self-property. The visualization of alliance developing stages illustrates that sub-alliances are sp lit in balance and self-connected. Compared with the Random Walker algorithm, the time cost and the number of forwarded messages in alliance-based mechanism is lower in service discovery. On three typical topologies (Grid, Random-Graph, Power-Law), the success rate of service discovery is much higher, which shows that self-organized alliances are helpful to enhance the discovery performance.

关键词： Kecloud service self-organizing alliance-based performance