The main structure and key techniques of our Virtual Exhibition Software are summarized. It demonstrates the practice of Software Engineering during the development of our project and discusses the use of UML in it.
According to the morphological structure characteristics of plants, the de- velopment mode for component-based virtual plants software was put forward, and the internal structure of plant organs component under this m...According to the morphological structure characteristics of plants, the de- velopment mode for component-based virtual plants software was put forward, and the internal structure of plant organs component under this mode were analyzed, thereby, the overall design mode for virtual plants software was given out, and its characteristics were estimated. Compared with traditional development modes of virtual plants software, component-based virtual plants software had significant advantages in code reusing, development efficiency and expansion of software functions.展开更多
In recent years,satellite networks have been proposed as an essential part of next-generation mobile communication systems.Software defined networking techniques are introduced in satellite networks to handle the grow...In recent years,satellite networks have been proposed as an essential part of next-generation mobile communication systems.Software defined networking techniques are introduced in satellite networks to handle the growing challenges induced by time-varying topology,intermittent inter-satellite link and dramatically increased satellite constellation size.This survey covers the latest progress of software defined satellite networks,including key techniques,existing solutions,challenges,opportunities,and simulation tools.To the best of our knowledge,this paper is the most comprehensive survey that covers the latest progress of software defined satellite networks.An open GitHub repository is further created where the latest papers on this topic will be tracked and updated periodically.Compared with these existing surveys,this survey contributes from three aspects:(1)an up-to-date SDN-oriented review for the latest progress of key techniques and solutions in software defined satellite networks;(2)an inspiring summary of existing challenges,new research opportunities and publicly available simulation tools for follow-up studies;(3)an effort of building a public repository to track new results.展开更多
为了缓解移动通信枢纽电力资源压力,解决硬件设备陈旧老化,满足当前业务量和数据量提取、转换和加载,通过云计算的分布式计算、虚拟化技术和ETL(Extraction-Transformation-Loading)工具等方法,对IDC(Internet Data Center)机房中BASS(B...为了缓解移动通信枢纽电力资源压力,解决硬件设备陈旧老化,满足当前业务量和数据量提取、转换和加载,通过云计算的分布式计算、虚拟化技术和ETL(Extraction-Transformation-Loading)工具等方法,对IDC(Internet Data Center)机房中BASS(Business Analysis Support System)系统的数据集市云架构进行了改造升级。经过实际测试应用表明,改造升级的BASS系统的数据集市在数据处理方面更加精细化;在数据量交互计算方面,更加均衡、稳定、高效;同时,降低了BASS系统整体运营成本,提高了基础资源的效率。展开更多
Despite extensive research, timing channels (TCs) are still known as a principal category of threats that aim to leak and transmit information by perturbing the timing or ordering of events. Existing TC detection appr...Despite extensive research, timing channels (TCs) are still known as a principal category of threats that aim to leak and transmit information by perturbing the timing or ordering of events. Existing TC detection approaches use either signature-based approaches to detect known TCs or anomaly-based approach by modeling the legitimate network traffic in order to detect unknown TCs. Un-fortunately, in a software-defined networking (SDN) environment, most existing TC detection approaches would fail due to factors such as volatile network traffic, imprecise timekeeping mechanisms, and dynamic network topology. Furthermore, stealthy TCs can be designed to mimic the legitimate traffic pattern and thus evade anomalous TC detection. In this paper, we overcome the above challenges by presenting a novel framework that harnesses the advantages of elastic re-sources in the cloud. In particular, our framework dynamically configures SDN to enable/disable differential analysis against outbound network flows of different virtual machines (VMs). Our framework is tightly coupled with a new metric that first decomposes the timing data of network flows into a number of using the discrete wavelet-based multi-resolution transform (DWMT). It then applies the Kullback-Leibler divergence (KLD) to measure the variance among flow pairs. The appealing feature of our approach is that, compared with the existing anomaly detection approaches, it can detect most existing and some new stealthy TCs without legitimate traffic for modeling, even with the presence of noise and imprecise timekeeping mechanism in an SDN virtual environment. We implement our framework as a prototype system, OBSERVER, which can be dynamically deployed in an SDN environment. Empirical evaluation shows that our approach can efficiently detect TCs with a higher detection rate, lower latency, and negligible performance overhead compared to existing approaches.展开更多
In order to overcome the limitation of vehicle engineering professional laboratory personnel and facilities,some of them is commonly used auxiliary software in the professional field for design,calculation and researc...In order to overcome the limitation of vehicle engineering professional laboratory personnel and facilities,some of them is commonly used auxiliary software in the professional field for design,calculation and research,including characteristics of software,application scope and methods are presented in this paper.Through these industries aided software powerful calculation,analysis functions and convenient visualization means,for the virtual simulation experiment,it can help to clearly illustrate the concept,deepen students’ understanding level of vehicle professional course,improve the enthusiasm of the students,improve the ability of autonomous learning and improve students ’ thinking ability and practice ability,and can effectively train highquality professionals with good quality.展开更多
Demands on software reliability and availability have increased tremendously due to the nature of present day applications. We focus on the aspect of software for the high availability of application servers since the...Demands on software reliability and availability have increased tremendously due to the nature of present day applications. We focus on the aspect of software for the high availability of application servers since the unavailability of servers more often originates from software faults rather than hardware faults. The software rejuvenation technique has been widely used to avoid the occurrence of unplanned failures, mainly due to the phenomena of software aging or caused by transient failures. In this paper, first we present a new way of using the virtual machine based software rejuvenation named VMSR to offer high availability for application server systems. Second we model a single physical server which is used to host multiple virtual machines （VMs） with the VMSR framework using stochastic modeling and evaluate it through both numerical analysis and SHARPE （Symbolic Hierarchical Automated Reliability and Performance Evaluator） tool simulation. This VMSR model is very general and can capture application server characteristics, failure behavior, and performability measures. Our results demonstrate that VMSR approach is a practical way to ensure uninterrupted availability and to optimize performance for aging applications.展开更多
Software-Defined Networking（SDN） decouples the control plane and the data plane in network switches and routers, which enables the rapid innovation and optimization of routing and switching configurations. However,t...Software-Defined Networking（SDN） decouples the control plane and the data plane in network switches and routers, which enables the rapid innovation and optimization of routing and switching configurations. However,traditional routing mechanisms in SDN, based on the Dijkstra shortest path, do not take the capacity of nodes into account, which may lead to network congestion. Moreover, security resource utilization in SDN is inefficient and is not addressed by existing routing algorithms. In this paper, we propose Route Guardian, a reliable securityoriented SDN routing mechanism, which considers the capabilities of SDN switch nodes combined with a Network Security Virtualization framework. Our scheme employs the distributed network security devices effectively to ensure analysis of abnormal traffic and malicious node isolation. Furthermore, Route Guardian supports dynamic routing reconfiguration according to the latest network status. We prototyped Route Guardian and conducted theoretical analysis and performance evaluation. Our results demonstrate that this approach can effectively use the existing security devices and mechanisms in SDN.展开更多
Research efforts for development of agricultural robots that can effectively perform tedious field tasks have grown significantly in the past decade.Agricultural robots are complex systems that require interdisciplina...Research efforts for development of agricultural robots that can effectively perform tedious field tasks have grown significantly in the past decade.Agricultural robots are complex systems that require interdisciplinary collaborations between different research groups for effective task delivery in unstructured crops and plants environments.With the exception of milking robots,the extensive research works that have been carried out in the past two decades for adaptation of robotics in agriculture have not yielded a commercial product to date.To accelerate this pace,simulation approach and evaluation methods in virtual environments can provide an affordable and reliable framework for experimenting with different sensing and acting mechanisms in order to verify the performance functionality of the robot in dynamic scenarios.This paper reviews several professional simulators and custom-built virtual environments that have been used for agricultural robotic applications.The key features and performance efficiency of three selected simulators were also compared.A simulation case study was demonstrated to highlight some of the powerful functionalities of the Virtual Robot Experimentation Platform.Details of the objects and scenes were presented as the proof-of-concept for using a completely simulated robotic platform and sensing systems in a virtual citrus orchard.It was shown that the simulated workspace can provide a configurable and modular prototype robotic system that is capable of adapting to several field conditions and tasks through easy testing and debugging of control algorithms with zero damage risk to the real robot and to the actual equipment.This review suggests that an open-source software platform for agricultural robotics will significantly accelerate effective collaborations between different research groups for sharing existing workspaces,algorithms,and reusing the materials.展开更多
Network Functions Virtualization(NFV) is an attempt to help operators more effectively manage their networks by implementing traditional network functions embedded in specialized hardware platforms in term of virtuali...Network Functions Virtualization(NFV) is an attempt to help operators more effectively manage their networks by implementing traditional network functions embedded in specialized hardware platforms in term of virtualized software instances. But, existing novel network appliances designed for NFV infrastructure are always architected on a general-purpose x86 server, which makes the performance of network functions limited by the hosted single server. To address this challenge, we propose ApplianceB ricks, a novel NFV-enable network appliance architecture that is used to explore the way of consolidating multiple physical network functions into a clustered network appliance, which is able to improve the processing capability of NFV-enabled network appliances.展开更多
Task-oriented virtual assistants are software systems that provide users with a natural language interface to complete domain-specific tasks.With the recent technological advances in natural language processing and ma...Task-oriented virtual assistants are software systems that provide users with a natural language interface to complete domain-specific tasks.With the recent technological advances in natural language processing and machine learning,an increasing number of task-oriented virtual assistants have been developed.However,due to the well-known complexity and difficulties of the natural language understanding problem,it is challenging to manage a task-oriented virtual assistant software project.Meanwhile,the management and experience related to the development of virtual assistants are hardly studied or shared in the research community or industry,to the best of our knowledge.To bridge this knowledge gap,in this paper,we share our experience and the lessons that we have learned at managing a task-oriented virtual assistant software project at Microsoft.We believe that our practices and the lessons learned can provide a useful reference for other researchers and practitioners who aim to develop a virtual assistant system.Finally,we have developed a requirement management tool,named SpecSpace,which can facilitate the management of virtual assistant projects.展开更多
我国城市轨道交通业务逐步向云平台集中,对网络时延、可靠性和资源调度能力提出了更高要求,而传统网络架构在多业务并发和高负载场景下的灵活性不足,故障恢复时间较长。针对该问题,将软件定义网络(Software Defined Network,SDN)技术引...我国城市轨道交通业务逐步向云平台集中,对网络时延、可靠性和资源调度能力提出了更高要求,而传统网络架构在多业务并发和高负载场景下的灵活性不足,故障恢复时间较长。针对该问题,将软件定义网络(Software Defined Network,SDN)技术引入城市轨道交通中心云,构建基于Spine-Leaf拓扑的SDN网络架构,并结合OpenFlow流表控制与虚拟扩展局域网(Virtual Extensible Local Area Network,VXLAN)实现网络统一调度。研究结果表明,相较于传统网络架构,SDN技术能够有效提升城市轨道交通云平台的网络性能和运维效率,为轨道交通智能化发展提供有力支撑。展开更多
文摘The main structure and key techniques of our Virtual Exhibition Software are summarized. It demonstrates the practice of Software Engineering during the development of our project and discusses the use of UML in it.
基金Supported by the National Natural Science Foundation of China(61062007)the Principal Fund Project of Tarim University,China(TDZKSS201115)~~
文摘According to the morphological structure characteristics of plants, the de- velopment mode for component-based virtual plants software was put forward, and the internal structure of plant organs component under this mode were analyzed, thereby, the overall design mode for virtual plants software was given out, and its characteristics were estimated. Compared with traditional development modes of virtual plants software, component-based virtual plants software had significant advantages in code reusing, development efficiency and expansion of software functions.
基金This work is supported by the Fundamental Research Funds for the Central Universities.
文摘In recent years,satellite networks have been proposed as an essential part of next-generation mobile communication systems.Software defined networking techniques are introduced in satellite networks to handle the growing challenges induced by time-varying topology,intermittent inter-satellite link and dramatically increased satellite constellation size.This survey covers the latest progress of software defined satellite networks,including key techniques,existing solutions,challenges,opportunities,and simulation tools.To the best of our knowledge,this paper is the most comprehensive survey that covers the latest progress of software defined satellite networks.An open GitHub repository is further created where the latest papers on this topic will be tracked and updated periodically.Compared with these existing surveys,this survey contributes from three aspects:(1)an up-to-date SDN-oriented review for the latest progress of key techniques and solutions in software defined satellite networks;(2)an inspiring summary of existing challenges,new research opportunities and publicly available simulation tools for follow-up studies;(3)an effort of building a public repository to track new results.
文摘为了缓解移动通信枢纽电力资源压力,解决硬件设备陈旧老化,满足当前业务量和数据量提取、转换和加载,通过云计算的分布式计算、虚拟化技术和ETL(Extraction-Transformation-Loading)工具等方法,对IDC(Internet Data Center)机房中BASS(Business Analysis Support System)系统的数据集市云架构进行了改造升级。经过实际测试应用表明,改造升级的BASS系统的数据集市在数据处理方面更加精细化;在数据量交互计算方面,更加均衡、稳定、高效;同时,降低了BASS系统整体运营成本,提高了基础资源的效率。
文摘Despite extensive research, timing channels (TCs) are still known as a principal category of threats that aim to leak and transmit information by perturbing the timing or ordering of events. Existing TC detection approaches use either signature-based approaches to detect known TCs or anomaly-based approach by modeling the legitimate network traffic in order to detect unknown TCs. Un-fortunately, in a software-defined networking (SDN) environment, most existing TC detection approaches would fail due to factors such as volatile network traffic, imprecise timekeeping mechanisms, and dynamic network topology. Furthermore, stealthy TCs can be designed to mimic the legitimate traffic pattern and thus evade anomalous TC detection. In this paper, we overcome the above challenges by presenting a novel framework that harnesses the advantages of elastic re-sources in the cloud. In particular, our framework dynamically configures SDN to enable/disable differential analysis against outbound network flows of different virtual machines (VMs). Our framework is tightly coupled with a new metric that first decomposes the timing data of network flows into a number of using the discrete wavelet-based multi-resolution transform (DWMT). It then applies the Kullback-Leibler divergence (KLD) to measure the variance among flow pairs. The appealing feature of our approach is that, compared with the existing anomaly detection approaches, it can detect most existing and some new stealthy TCs without legitimate traffic for modeling, even with the presence of noise and imprecise timekeeping mechanism in an SDN virtual environment. We implement our framework as a prototype system, OBSERVER, which can be dynamically deployed in an SDN environment. Empirical evaluation shows that our approach can efficiently detect TCs with a higher detection rate, lower latency, and negligible performance overhead compared to existing approaches.
基金supported by Henan Polytechnic University Education Teaching Reform Research Projects(No.2015JG034)
文摘In order to overcome the limitation of vehicle engineering professional laboratory personnel and facilities,some of them is commonly used auxiliary software in the professional field for design,calculation and research,including characteristics of software,application scope and methods are presented in this paper.Through these industries aided software powerful calculation,analysis functions and convenient visualization means,for the virtual simulation experiment,it can help to clearly illustrate the concept,deepen students’ understanding level of vehicle professional course,improve the enthusiasm of the students,improve the ability of autonomous learning and improve students ’ thinking ability and practice ability,and can effectively train highquality professionals with good quality.
基金supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) under Grant No. KRF2007-210-D00006
文摘Demands on software reliability and availability have increased tremendously due to the nature of present day applications. We focus on the aspect of software for the high availability of application servers since the unavailability of servers more often originates from software faults rather than hardware faults. The software rejuvenation technique has been widely used to avoid the occurrence of unplanned failures, mainly due to the phenomena of software aging or caused by transient failures. In this paper, first we present a new way of using the virtual machine based software rejuvenation named VMSR to offer high availability for application server systems. Second we model a single physical server which is used to host multiple virtual machines （VMs） with the VMSR framework using stochastic modeling and evaluate it through both numerical analysis and SHARPE （Symbolic Hierarchical Automated Reliability and Performance Evaluator） tool simulation. This VMSR model is very general and can capture application server characteristics, failure behavior, and performability measures. Our results demonstrate that VMSR approach is a practical way to ensure uninterrupted availability and to optimize performance for aging applications.
基金supported in part by the National Natural Science Foundation of China (Nos. 61402029, 61370190, and 61379002)the National Key Basic Research Program (973) of China (No. 2012CB315905)
文摘Software-Defined Networking（SDN） decouples the control plane and the data plane in network switches and routers, which enables the rapid innovation and optimization of routing and switching configurations. However,traditional routing mechanisms in SDN, based on the Dijkstra shortest path, do not take the capacity of nodes into account, which may lead to network congestion. Moreover, security resource utilization in SDN is inefficient and is not addressed by existing routing algorithms. In this paper, we propose Route Guardian, a reliable securityoriented SDN routing mechanism, which considers the capabilities of SDN switch nodes combined with a Network Security Virtualization framework. Our scheme employs the distributed network security devices effectively to ensure analysis of abnormal traffic and malicious node isolation. Furthermore, Route Guardian supports dynamic routing reconfiguration according to the latest network status. We prototyped Route Guardian and conducted theoretical analysis and performance evaluation. Our results demonstrate that this approach can effectively use the existing security devices and mechanisms in SDN.
文摘Research efforts for development of agricultural robots that can effectively perform tedious field tasks have grown significantly in the past decade.Agricultural robots are complex systems that require interdisciplinary collaborations between different research groups for effective task delivery in unstructured crops and plants environments.With the exception of milking robots,the extensive research works that have been carried out in the past two decades for adaptation of robotics in agriculture have not yielded a commercial product to date.To accelerate this pace,simulation approach and evaluation methods in virtual environments can provide an affordable and reliable framework for experimenting with different sensing and acting mechanisms in order to verify the performance functionality of the robot in dynamic scenarios.This paper reviews several professional simulators and custom-built virtual environments that have been used for agricultural robotic applications.The key features and performance efficiency of three selected simulators were also compared.A simulation case study was demonstrated to highlight some of the powerful functionalities of the Virtual Robot Experimentation Platform.Details of the objects and scenes were presented as the proof-of-concept for using a completely simulated robotic platform and sensing systems in a virtual citrus orchard.It was shown that the simulated workspace can provide a configurable and modular prototype robotic system that is capable of adapting to several field conditions and tasks through easy testing and debugging of control algorithms with zero damage risk to the real robot and to the actual equipment.This review suggests that an open-source software platform for agricultural robotics will significantly accelerate effective collaborations between different research groups for sharing existing workspaces,algorithms,and reusing the materials.
基金supported by Program for National Basic Research Program of China (973 Program) "Reconfigurable Network Emulation Testbed for Basic Network Communication"
文摘Network Functions Virtualization(NFV) is an attempt to help operators more effectively manage their networks by implementing traditional network functions embedded in specialized hardware platforms in term of virtualized software instances. But, existing novel network appliances designed for NFV infrastructure are always architected on a general-purpose x86 server, which makes the performance of network functions limited by the hosted single server. To address this challenge, we propose ApplianceB ricks, a novel NFV-enable network appliance architecture that is used to explore the way of consolidating multiple physical network functions into a clustered network appliance, which is able to improve the processing capability of NFV-enabled network appliances.
文摘Task-oriented virtual assistants are software systems that provide users with a natural language interface to complete domain-specific tasks.With the recent technological advances in natural language processing and machine learning,an increasing number of task-oriented virtual assistants have been developed.However,due to the well-known complexity and difficulties of the natural language understanding problem,it is challenging to manage a task-oriented virtual assistant software project.Meanwhile,the management and experience related to the development of virtual assistants are hardly studied or shared in the research community or industry,to the best of our knowledge.To bridge this knowledge gap,in this paper,we share our experience and the lessons that we have learned at managing a task-oriented virtual assistant software project at Microsoft.We believe that our practices and the lessons learned can provide a useful reference for other researchers and practitioners who aim to develop a virtual assistant system.Finally,we have developed a requirement management tool,named SpecSpace,which can facilitate the management of virtual assistant projects.
文摘我国城市轨道交通业务逐步向云平台集中,对网络时延、可靠性和资源调度能力提出了更高要求,而传统网络架构在多业务并发和高负载场景下的灵活性不足,故障恢复时间较长。针对该问题,将软件定义网络(Software Defined Network,SDN)技术引入城市轨道交通中心云,构建基于Spine-Leaf拓扑的SDN网络架构,并结合OpenFlow流表控制与虚拟扩展局域网(Virtual Extensible Local Area Network,VXLAN)实现网络统一调度。研究结果表明,相较于传统网络架构,SDN技术能够有效提升城市轨道交通云平台的网络性能和运维效率,为轨道交通智能化发展提供有力支撑。
