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An Efficient Memory Management for Mobile Operating Systems Based on Prediction of Relaunch Distance
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作者 Jaehwan Lee Sangoh Park 《Computer Systems Science & Engineering》 SCIE EI 2023年第10期171-186,共16页
Recently,various mobile apps have included more features to improve user convenience.Mobile operating systems load as many apps into memory for faster app launching and execution.The least recently used(LRU)-based ter... Recently,various mobile apps have included more features to improve user convenience.Mobile operating systems load as many apps into memory for faster app launching and execution.The least recently used(LRU)-based termination of cached apps is a widely adopted approach when free space of the main memory is running low.However,the LRUbased cached app termination does not distinguish between frequently or infrequently used apps.The app launch performance degrades if LRU terminates frequently used apps.Recent studies have suggested the potential of using users’app usage patterns to predict the next app launch and address the limitations of the current least recently used(LRU)approach.However,existing methods only focus on predicting the probability of the next launch and do not consider how soon the app will launch again.In this paper,we present a new approach for predicting future app launches by utilizing the relaunch distance.We define the relaunch distance as the interval between two consecutive launches of an app and propose a memory management based on app relaunch prediction(M2ARP).M2ARP utilizes past app usage patterns to predict the relaunch distance.It uses the predicted relaunch distance to determine which apps are least likely to be launched soon and terminate them to improve the efficiency of the main memory. 展开更多
关键词 Mobile operating systems memory management background app caching relaunch distance neural networks
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Design of secure operating systems with high security levels 被引量:5
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作者 QING SiHan1,2 & SHEN ChangXiang3 1 Institute of Software, Chinese Academy of Sciences, Beijing 100080, China 2 School of Software and Microelectronics, Peking University, Beijing 102600, China 3 Institute of Computing Technology, Navy, Beijing 100841, China 《Science in China(Series F)》 2007年第3期399-418,共20页
Numerous Internet security incidents have shown that support from secure operating systems is paramount to fighting threats posed by modern computing environments. Based on the requirements of the relevant national an... Numerous Internet security incidents have shown that support from secure operating systems is paramount to fighting threats posed by modern computing environments. Based on the requirements of the relevant national and international standards and criteria, in combination with our experience in the design and development of the ANSHENG v4.0 secure operating system with high security level (hereafter simply referred to as ANSHENG OS), this paper addresses the following key issues in the design of secure operating systems with high security levels: security architecture, security policy models, and covert channel analysis. The design principles of security architecture and three basic security models: confidentiality, integrity, and privilege control models are discussed, respectively. Three novel security models and new security architecture are proposed. The prominent features of these proposals, as well as their applications to the ANSHENG OS, are elaborated. Cover channel analysis (CCA) is a well-known hard problem in the design of secure operating systems with high security levels since to date it lacks a sound theoretical basis and systematic analysis approach. In order to resolve the fundamental difficulties of CCA, we have set up a sound theoretical basis for completeness of covert channel identification and have proposed a unified framework for covert channel identification and an efficient backward tracking search method. The successful application of our new proposals to the ANSHENG OS has shown that it can help ease and speedup the entire CCA process. 展开更多
关键词 secure operating systems with high security levels ARCHITECTURE security model covert channel analysis
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Cybersecurity: Identifying the Vulnerability Intensity Function (VIF) and Vulnerability Index Indicator (VII) of a Computer Operating System
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作者 Ranju Karki Chris P. Tsokos 《Journal of Information Security》 2022年第4期337-362,共26页
The objective of the present study is to define two important aspects of the computer operating system concerning the number of its vulnerabilities behavior. We identify the Vulnerability Intensity Function (VIF), and... The objective of the present study is to define two important aspects of the computer operating system concerning the number of its vulnerabilities behavior. We identify the Vulnerability Intensity Function (VIF), and the Vulnerability Index Indicator (VII) of a computer operating network. Both of these functions, VIF and VII are entities of the stochastic process that we have identified, which characterizes the probabilistic behavior of the number of vulnerabilities of a computer operating network. The VIF identifies the rate at which the number of vulnerabilities changes with respect to time. The VII is an important index indicator that conveys the following information about the number of vulnerabilities of Desktop Operating Systems: the numbers are increasing, decreasing, or remaining the same at a particular time of interest. This decision type of index indicator is crucial in every strategic planning and decision-making. The proposed VIF and VII illustrate their importance by using real data for Microsoft Windows Operating Systems 10, 8, 7, and Apple MacOS. The results of the actual data attest to the importance of VIF and VII in the cybersecurity problem we are currently facing. 展开更多
关键词 CYBERSECURITY operating systems Vulnerabilities Stochastic Process Vulnerability Intensity Function Vulnerability Index Indicator
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Iterative Solution for Systems of Nonlinear Two Binary Operator Equations 被引量:2
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作者 ZHANGZhi-hong LIWen-feng 《Chinese Quarterly Journal of Mathematics》 CSCD 2004年第3期262-266,共5页
Using the cone and partial ordering theory and mixed monotone operator theory, the existence and uniqueness of solutions for some classes of systems of nonlinear two binary operator equations in a Banach space with a ... Using the cone and partial ordering theory and mixed monotone operator theory, the existence and uniqueness of solutions for some classes of systems of nonlinear two binary operator equations in a Banach space with a partial ordering are discussed. And the error estimates that the iterative sequences converge to solutions are also given. Some relevant results of solvability of two binary operator equations and systems of operator equations are improved and generalized. 展开更多
关键词 Banach spaces two binary operators systems of operator equations iterative solution
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A GENERAL MATHEMATICAL FRAMEWORK OF COMPLEX SYSTEMS(Ⅰ)
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作者 Zan Ting-quan 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1993年第4期385-394,共10页
The fundamental and simplest structure of a complex system is a network.According to this idea,we plan to develop a general methematical framework of complex systems.In this paper,we discuss in detail the concept of s... The fundamental and simplest structure of a complex system is a network.According to this idea,we plan to develop a general methematical framework of complex systems.In this paper,we discuss in detail the concept of systems,a general description of systems:System=(Hardware,Software,Environment),and whole-part relations,including relations between elements and systems,subsystems and systems,and between systems.The rules of operations of systems are given,and the induced transformations between hardware and software of systems are briefly discussed. 展开更多
关键词 complex systems HARDWARE SOFTWARE operations of systems induced transformations mathematical framework
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TENSOR SUM AND DYNAMICAL SYSTEMS
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作者 D.SENTHILKUMAR P.CHANDRA KALA 《Acta Mathematica Scientia》 SCIE CSCD 2014年第6期1935-1946,共12页
In this paper we introduce the concept of tensor sum semigroups. Also we have given the examples of tensor sum operators which induce dynamical system on weighted locally convex function spaces.
关键词 tensor sum composition operators multiplication operator dynamical systems seminorm operator valued mapping
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Operations Support Systems Standards:Status Quo and Trends
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作者 Wang Yanchuan Kong Lingping (China Telecom Corporation,Beijing 100032,China) 《ZTE Communications》 2006年第1期26-29,共4页
The emerging of diversified new telecommunications technologies leads to a continuous change of telecom networks. Consequently, the operations support systems of telecommunications operators are facing structure adjus... The emerging of diversified new telecommunications technologies leads to a continuous change of telecom networks. Consequently, the operations support systems of telecommunications operators are facing structure adjustments as well as new systems construction. In this situation, new generation operations support systems standards are urgently required. Several standardization organizations have made substantial progress in the study of the new generation standards, such as ITU' s study on Next Generation Network (NGN) management, TMF's on New Generation Operations Systems and Software (NGOSS) and CCSA's on network management standards. However, the existing operations support systems face the challenges of architecture improvement, change of the focus of operations support, orientation of customers' demands and technology evolution. 展开更多
关键词 ITU NGN CCSA Operations Support systems Standards ETOM OSS ITIL GPP TMN SG
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The Coupled Operational Systems:A Linear Optimisation Review
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作者 Said El Noshokaty 《Journal of Economic Science Research》 2019年第2期40-49,共10页
The purpose of this review is to summarise the existing literature on the operational systems as to explain the current state of understanding on the coupled operational systems.The review only considers the linear op... The purpose of this review is to summarise the existing literature on the operational systems as to explain the current state of understanding on the coupled operational systems.The review only considers the linear optimisation of the operational systems.Traditionally,the operational systems are classified as decoupled,tightly coupled,and loosely coupled.Lately,the coupled operational systems were classified as systems of time-sensitive and time-insensitive operational cycle,systems employing one mix and different mixes of factors of production,and systems of single-linear,single-linear-fractional,and multi-linear objective.These new classifications extend the knowledge about the linear optimisation of the coupled operational systems and reveal new objective-improving models and new state-of-the-art methodologies never discussed before.Business areas affected by these extensions include product assembly lines,cooperative farming,gas/oil reservoir development,maintenance service throughout multiple facilities,construction via different locations,flights traffic control in aviation,game reserves,and tramp shipping in maritime cargo transport. 展开更多
关键词 Operational systems Coupled systems Assembly lines Facility location Distributed systems Resource allocation Factors of production Linear optimisation
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Study of Models for Heating Power Station Operator Training Systems
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作者 Sholpan Muratkyzy Baimatayeva Yuriy Vladimirovitch Shevyakov 《Journal of Energy and Power Engineering》 2013年第1期162-167,共6页
This paper is devoted to development and study of models for operator training systems of heating power station processes management. It proposed a mathematical model describing the management processes of heating pow... This paper is devoted to development and study of models for operator training systems of heating power station processes management. It proposed a mathematical model describing the management processes of heating power units of the technological complex considering the relationship of technological variables in deviations effective in real time. A software complex is developed for the system of training of operators controlling processes in heating station units. Obtained results may be used in the course of development of computer training systems for operators of heating power stations with cross-linkage. 展开更多
关键词 Training systems of operators steam generator simulation model heating power stations
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ARM-Based Embedded System Platform and Its Portability Research
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作者 Hao Liu 《Journal of Computer and Communications》 2023年第11期51-63,共13页
Taking ARM as the hardware platform, the embedded system is built from both hardware and software aspects with the application as the center. In the hardware design, build the hardware platform scheme, design the sche... Taking ARM as the hardware platform, the embedded system is built from both hardware and software aspects with the application as the center. In the hardware design, build the hardware platform scheme, design the schematic diagram as well as PCB, complete the hardware debugging, and ensure the system hardware platform function;in the software design, optimize the three-stage pipeline structure of ARM instruction system, design the instruction set, install the embedded system on the virtual machine, build the cross-toolchain, and set up the correct NFS network file system. Finish the design of the ARM-based embedded system platform, combined with the hardware requirements of the experimental platform, transplant the powerful Uboot as the Bootloader of the system, and further transplant the Linux-2.6. 32 kernel to the system start the operation normally, and finally, build the root file to finish the study of its portability. 展开更多
关键词 Embedded Platforms PORTABILITY operating systems
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MAC isolation to realize effective management in public wireless LAN
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作者 陈立全 胡爱群 计文柯 《Journal of Southeast University(English Edition)》 EI CAS 2004年第2期157-161,共5页
This paper describes how to use medium access control (MAC) isolation to enhance management performance in public wireless LAN (PWLAN). To comply with the IEEE 802.11 standards, a scheme to implement MAC isolation in ... This paper describes how to use medium access control (MAC) isolation to enhance management performance in public wireless LAN (PWLAN). To comply with the IEEE 802.11 standards, a scheme to implement MAC isolation in WLAN access points by re-designing the Distribution_Service component of the MAC state machine is proposed. A variable named dotl 1 Isolation is defined to determine whether the MAC level communication between wireless stations in the same BSS is permitted or not. Finally, a design solution based on MPC860 hardware and embedded Linux software for PWLAN access point is specified. The simulation results of MAC isolation for PWLAN show that the proposed scheme is feasible and effective. 展开更多
关键词 Codes (standards) Computer operating systems Computer simulation Network protocols Wireless telecommunication systems
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High performance reconfigurable hardware system for real-time image processing
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作者 赵广州 张天序 +2 位作者 王岳环 曹治国 左峥嵘 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第3期502-509,共8页
A novel reconfigurable hardware system which uses both muhi-DSP and FPGA to attain high performance and real-time image processing are presented. The system structure and working principle of mainly processing multi-B... A novel reconfigurable hardware system which uses both muhi-DSP and FPGA to attain high performance and real-time image processing are presented. The system structure and working principle of mainly processing multi-BSP board, extended multi-DSP board are analysed. The outstanding advantage is that the communication among different board components of this system is supported by high speed link ports & serial ports for increasing the system performance and computational power. Then the implementation of embedded real-time operating systems (RTOS) by us is discussed in detail. In this system, we adopt two kinds of parallel structures controlled by RTOS for parallel processing of algorithms. The experimental results show that exploitive period of the system is short, and maintenance convenient. Thus it is suitable for real-time image processing and can get satisfactory effect of image recognition. 展开更多
关键词 MULTI-DSP fidd programmable gate arrays real-time image processing real time operating systems parallel structure.
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Relative Time Quantum-based Enhancements in Round Robin Scheduling
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作者 Sardar Zafar Iqbal Hina Gull +5 位作者 Saqib Saeed Madeeha Saqib Mohammed Alqahtani Yasser A.Bamarouf Gomathi Krishna May Issa Aldossary 《Computer Systems Science & Engineering》 SCIE EI 2022年第5期461-477,共17页
Modern human life is heavily dependent on computing systems and one of the core components affecting the performance of these systems is underlying operating system.Operating systems need to be upgraded to match the n... Modern human life is heavily dependent on computing systems and one of the core components affecting the performance of these systems is underlying operating system.Operating systems need to be upgraded to match the needs of modern-day systems relying on Internet of Things,Fog computing and Mobile based applications.The scheduling algorithm of the operating system dictates that how the resources will be allocated to the processes and the Round Robin algorithm(RR)has been widely used for it.The intent of this study is to ameliorate RR scheduling algorithm to optimize task scheduling.We have carried out an experimental study where we have developed four variations of RR,each algorithm considers three-time quanta and the performance of these variations was compared with the RR algorithm,and results highlighted that these variations performed better than conventional RR algorithm.In the future,we intend to develop an automated scheduler that can determine optimal algorithm based on the current set of processes and will allocate time quantum to the processes intelligently at the run time.This way the task performance of modern-day systems can be improved to make them more efficient. 展开更多
关键词 CPU scheduling Round Robin enhanced Round Robin relative time quantum operating systems
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Source Code Comparison of DOS and CP/M
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作者 Bob Zeidman 《Journal of Computer and Communications》 2016年第12期1-38,共38页
In a previous paper [1], I compared DOS from Microsoft and CP/M from Digital Research Inc. (DRI) to determine whether the original DOS source code had been copied from CP/M source code as had been rumored for many yea... In a previous paper [1], I compared DOS from Microsoft and CP/M from Digital Research Inc. (DRI) to determine whether the original DOS source code had been copied from CP/M source code as had been rumored for many years [2] [3]. At the time, the source code for CP/M was publicly available but the source code for DOS was not. My comparison was limited to the comparison of the DOS 1.11 binary code and the source code for CP/M 2.0 from 1981. Since that time, the Computer History Museum in Mountain View, California received the source code for DOS 2.0 from Microsoft and was given permission to make it public. The museum also received the source code for DOS 1.1 from Tim Paterson, the developer who was originally contracted by Microsoft to write DOS. In this paper, I perform a further analysis using the newly accessible source code and determine that no code was copied. I further conclude that the commands were not copied but that a substantial number of the system calls were copied. 展开更多
关键词 Copyright Infringement CP/M Digital Research DOS Intellectual Property MICROSOFT operating systems Software Forensics
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Social Energy:Mining Energy From the Society 被引量:2
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作者 Jun Jason Zhang David Wenzhong Gao +6 位作者 Yingchen Zhang Xiao Wang Xiangyang Zhao Dongliang Duan Xiaoxiao Dai Jun Hao Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第3期466-482,共17页
The inherent nature of energy,i.e.,physicality,sociality and informatization,implies the inevitable and intensive interaction between energy systems and social systems.From this perspective,we define "social ener... The inherent nature of energy,i.e.,physicality,sociality and informatization,implies the inevitable and intensive interaction between energy systems and social systems.From this perspective,we define "social energy" as a complex sociotechnical system of energy systems,social systems and the derived artificial virtual systems which characterize the intense intersystem and intra-system interactions.The recent advancement in intelligent technology,including artificial intelligence and machine learning technologies,sensing and communication in Internet of Things technologies,and massive high performance computing and extreme-scale data analytics technologies,enables the possibility of substantial advancement in socio-technical system optimization,scheduling,control and management.In this paper,we provide a discussion on the nature of energy,and then propose the concept and intention of social energy systems for electrical power.A general methodology of establishing and investigating social energy is proposed,which is based on the ACP approach,i.e., "artificial systems"(A), "computational experiments"(C) and "parallel execution"(P),and parallel system methodology.A case study on the University of Denver(DU) campus grid is provided and studied to demonstrate the social energy concept.In the concluding remarks,we discuss the technical pathway,in both social and nature sciences,to social energy,and our vision on its future. 展开更多
关键词 ACP distribution locational marginal pricing intelligent operation in power systems parallel control parallel intelligence parallel management social energy socio-technical energy systems
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Elimination of Partial Overloading of Generators Under Unbalanced Operating Conditions of Power Systems
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作者 Sudhakar Reddy Sama Subrata Paul Sunita Halder Nee Dey 《CSEE Journal of Power and Energy Systems》 SCIE 2016年第1期81-87,共7页
Unbalanced operating condition in a power system can cause partial overloading of the generators in the network,a condition where one or two of the three phases of the generator become overloaded even if the total 3-p... Unbalanced operating condition in a power system can cause partial overloading of the generators in the network,a condition where one or two of the three phases of the generator become overloaded even if the total 3-phase power output of the generator is within its specified limit.Partial overloading of generators beyond certain limits is undesirable and must be avoided.Distribution systems are often subjected to highly unbalanced operating conditions.Introduction of distributed generations(DGs),therefore,has rendered today’s distribution systems quite susceptible to this problem.Mitigation of this problem requires the issue to be addressed properly during analysis,operation and planning of such systems.Analysis,operation and planning of power networks under unbalanced operating condition require 3-phase load flow study.The existing methods of 3-phase load flow are not equipped to take into account any limit on the loadings of the individual phases of the generators.In the present work,a methodology based on NewtonRaphson(N-R)3-phase load flow with necessary modifications is proposed.The proposed methodology is able to determine the safe loading limits of the generators,and,can be adopted for operation and planning of power networks under unbalanced operating conditions to overcome the above difficulties.Test results on IEEE-37 bus feeder network are presented to demonstrate the effectiveness of the proposed method. 展开更多
关键词 Newton Raphson 3-phase load flow partial overloading of generators unbalanced operating condition of power systems
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Evidence Emerging from the Survey on European Union Timber Regulation [REG. (EU) 995/2010] in Italy
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作者 Hadžić Nermin Carbone Francesco 《Open Journal of Forestry》 2022年第1期142-161,共20页
Illegal logging is a pervasive problem of major international concern that causes many negative social, economical and environmental consequences. EUTR is a tool adopted in 2010 and entered into force in 2013 to stop ... Illegal logging is a pervasive problem of major international concern that causes many negative social, economical and environmental consequences. EUTR is a tool adopted in 2010 and entered into force in 2013 to stop the trade of timber illegally logged within the EU market. The implementation in Italy is still in progress and varies among regions. This study considers the respondents’ opinions on different EUTR characteristics, implementation processes and compliance activities. Taking Italy as an example, the questionnaire was delivered to relevant Italian foresters and timber operators in the forest-timber system. Two hypotheses are under verification: </span></span><span><span><span style="font-family:"">1</span></span></span><span><span><span style="font-family:"">) if Italian forest-wood-timber sector integrated EUTR into its activity and </span></span></span><span><span><span style="font-family:"">2</span></span></span><span><span><span style="font-family:"">) if the Italian Due Diligence system is a valid model to other countries. The questionnaire has been submitted to the wood industry stakeholders. It has been organized into six sections to collect information about the professional characteristics of respondents, their experiences on EUTR, the opinion about EUTR and FLEGT, the support received on EUTR implementation, the opinion about the checks system, and the role of EUTR in marketing timber products. Questionnaire data have been elaborated in different ways. Conclusion underlines the EUTR Italian system criticalities and some suggestions for a more effective use of EUTR in the wood market. The picture that emerges from the results collected is that the EUTR, although proposed for morally and ethically valid purposes, doesn’t have unanimous effectiveness. In particular, EUTR can generate a distortion of the market, new expenditures for importers. Various operators applaud the role of certification schemes for sustainable forest management, which indirectly makes it possible to prevent the aforementioned problem. The Italian EUTR system is working only for satisfying Regulation 995/2010 targets. This must be considered as the starting point;however, three innovative topics could be developed in the future: digitalization and computerization of EUTR certification, integration of EUTR certification with forest certifications schemes and other quality certifications, and use of EUTR in the marketing initiatives. 展开更多
关键词 EUTR Illegal Logging Implementation QUESTIONNAIRE Foresters and Timber Operators in the Forest-Timber systems
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Operating System Support for High-performance Networking: a Survey
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作者 LIUZhi-qing WANGPeng 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2004年第3期32-42,共11页
Crucial applications require direct and efficient access to emerging high-performance networks. This paper surveys the networking subsystem overhead for high-performance networking and the current operating system tec... Crucial applications require direct and efficient access to emerging high-performance networks. This paper surveys the networking subsystem overhead for high-performance networking and the current operating system techniques to address the overhead. This paper aims to identify a few directions for future research work. 展开更多
关键词 operating systems networking subsystem design
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Object-oriented Modeling for Planning and Control of Multi-energy Systems 被引量:2
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作者 Stefan Bschorer Maren Kuschke Kai Strunz 《CSEE Journal of Power and Energy Systems》 SCIE CSCD 2019年第3期355-364,共10页
Multi-energy systems(MES)involving networks of different energy carriers can support the balancing of fluctuating renewable generation by co-ordinated joint operation.In this paper,an object-oriented modeling methodol... Multi-energy systems(MES)involving networks of different energy carriers can support the balancing of fluctuating renewable generation by co-ordinated joint operation.In this paper,an object-oriented modeling methodology for planning and operations control of MES based on nodal analysis is proposed.The framework provides the modularity to simulate scenarios with varying network configurations.Based on object-oriented programming,classes are formed with regard to common attributes of the network elements.The instances of classes represent physical network elements,such as buses,lines,and power conversion units.The models of the individual network elements involve adjustable and flexible parameters.This is especially advantageous for scenarios with operatingpoint-dependent efficiencies.The overall framework makes use of a uniform description of the model parameters across the diverse energy carriers.Thus,the methodology is particularly suited for the analysis of MES.The applicability of the modeling framework is demonstrated by two use cases involving a technology campus in Berlin. 展开更多
关键词 Control of multi-energy systems cooling network demand-side management electric network heating network object-oriented programming operations control of multi-energy systems planning of multi-energy systems smart grids
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An Adaptive Sliding Mode Control of Delta Operator Systems with Input Nonlinearity Containing Unknown Slope Parameters
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作者 LIU Leipo FU Zhumu SONG Xiaona 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2017年第3期535-549,共15页
The problem of observer-based adaptive sliding mode control of delta operator systems with time-varying delays subject to input nonlinearity is investigated. The slope parameters of this nonlinearity are unmeasured. A... The problem of observer-based adaptive sliding mode control of delta operator systems with time-varying delays subject to input nonlinearity is investigated. The slope parameters of this nonlinearity are unmeasured. A novel adaptive control law is established such that the sliding surface in the state-estimation space can be reached in a finite time. A delay-dependent sufficient condition for the asymptotic stability of both the error system and the sliding mode dynamics is derived via linear matrix inequality(LMI). Finally, a simulation example is presented to show the validity and advantage of the proposed method. 展开更多
关键词 Delta operator systems input nonlinearity linear matrix inequality sliding mode control time-varying delays.
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