定风量系统中空调房间建模与Matlab仿真

本文介绍了定风量空调系统的基本原理,着重对定风量(CAV)空调系统房间数学模型进行了推导。最后文章利用仿真软件Matlab对整个空调控制系统进行了仿真,得到了良好的系统响应。     

交叉口混合交通流微观控制模型

为构建智能网联汽车(CAV)和有人驾驶汽车(HDV)混合通行情况下的交叉口通行机制与控制方法, 本文提出CAV专用道条件下交叉口协同通行模型. 首先, 设计CAV专用道条件下的交叉口布置, 对交叉口进行网格化处理,将CAV通行时隙和HDV绿灯相位对交叉口某部分网格某时段的占用统一到交叉口时空资源描述框架下; 其次, 建立兼顾CAV与HDV的交叉口时空网格资源分配模型, 构建自适应信号灯控制算法和CAV轨迹规划算法; 再次, 以车辆最小延误为目标进行自适应信号灯配时优化和CAV轨迹优化; 最后, 选取广州某典型交叉口建立仿真实验对所提方法的有效性进行了验证.     

2010 CAV award announcement

The 2010 CAV (Computer-Aided Verification) award was awarded to Kenneth L. McMillan of Cadence Research Laboratories for a series of fundamental contributions resulting in significant advances in scalability of model checking tools. The annual award recognizes a specific fundamental contribution or a series of outstanding contributions to the CAV field.     

The role of inspection in software quality assurance

Due to the complexity of the code, software is released with many errors. In response, both software practitioners and software researchers need to improve the reputation of the software. Inspection is the only way to improve the quality of software. Inspection methods can be more effective but success depends on having a sound and systematic procedure for conducting the inspection. The Workshop on Inspection in Software Engineering (WISE), a satellite event of the 2001 Computer Aided Verification (CAV '01) Conference, brought together researchers, practitioners, and regulators in the hope of finding effective approaches to software inspection. The workshop included invited lectures and paper presentations in the form of panel discussions on all aspects of software inspection. Submissions explained how practitioners and researchers were performing inspections, discussed the relevance of inspections, provided evidence of how inspections could be improved through refinement of the inspection process and computer aided tool support and explained how careful design of software could make inspections easier or more effective.     

Design and Results of the First Satisfiability Modulo Theories Competition (SMT-COMP 2005)

The Satisfiability Modulo Theories Competition (SMT-COMP) is intended to spark further advances in the decision procedures field, especially for applications in hardware and software verification. Public competitions are a well-known means of stimulating advancement in automated reasoning. Evaluation of SMT solvers entered in SMT-COMP took place while CAV 2005 was meeting. Twelve solvers were entered; 1,352 benchmarks were collected in seven different divisions.     

基于事件触发机制的双编队车辆换道决策模型

针对由联网自动化车辆(connected and automated vehicle,CAV)组成的双编队车辆换道问题进行了研究,提出了一种基于事件触发的分布式换道决策模型.该模型针对双编队系统设计了一种编队内和编队间的一致性控制协议;同时,为了减少CAV车辆控制器的频繁更新,设计了一种基于组合测量方式的事件触发器,并给出Lyapunov函数证明了算法的稳定性且不存在Zeno行为.仿真结果表明,所设计的控制协议能够使双编队系统收敛一致,有效降低CAV控制器的更新频率,减少系统能耗.通过模型对比,在证明所提决策模型有效性的同时,系统能够更快地收敛.     

光盘光道布局与性能

同心圆光道与螺旋线光道在光记录性能上各有其特色．与恒角速度（ＣＡＶ）布局相比，恒线速度（ＣＬＶ）布局增大了数据存储容量，却增长了存取时间．分区恒角速度（Ｚ－ＣＡＶ）布局具有介于恒角速度式布局和恒线速度布局之间的性能。改进恒角速度（ＭＣＡＶ）式记录方式，利用可变数据传输率通道，可在分区恒角速度式记录方式的基础上获得恒角速度布局的存取速度和恒线速度布局的数据存储容量。     

A comprehensive analytical performance model for disk devices underrandom workloads

Our goal is to contribute a common theoretical framework for studying the performance of disk-storage devices. Understanding the performance behavior of these devices will allow prediction of the I/O cost in modern applications. Current disk technologies differ in terms of the fundamental modeling characteristics, which include the magnetic/optical nature, angular and linear velocities, storage capacities, and transfer rates. Angular and linear velocities, storage capacities, and transfer rates are made constant or variable in different existing disk products. Related work in this area has studied Constant Angular Velocity (CAV) magnetic disks and Constant Linear Velocity (CLV) optical disks. We present a comprehensive analytical model, validated through simulations, for the random retrieval performance of disk devices which takes into account all the above-mentioned fundamental characteristics and includes, as special cases, all the known disk-storage devices. Such an analytical model can be used, for example, in the query optimizer of large traditional databases as well as in an admission controller of multimedia storage servers. Besides the known models for magnetic CAV and optical CLV disks, our unifying model is also reducible to a model for a more recent disk technology, called zoned disks, the retrieval performance of which has not been modeled in detail before. The model can also be used to study the performance retrieval of possible future technologies which combine a number of the above characteristics and in environments containing different types of disks (e.g., magnetic-disk-based secondary storage and optical-disk-based tertiary storage). Using our model, we contribute an analysis of the performance behavior of zoned disks and we compare it against that for the traditional CAV disks, as well as against that of some possible/future technologies. This allows us to gain insights into the fundamental performance trade-offs     

SoftMC 2003: Workshop on Software Model Checking

This volume contains the Proceedings of the 2^nd Workshop on Software Model Checking, which was held on 14 July 2003 in Boulder, Colorado. The Workshop was a satellite event of the Conference on Computer Aided Verification (CAV) 2003.The first Workshop on Software Model Checking (SoftMC) was held in 2001. Since that time, the field has grown tremendously and we've made a lot of progress in pushing the state-of-the-art. We are now entering a stage where the strengths and limitations of the current approaches are perhaps better understood. With this in mind we invited Dawson Engler to open the workshop with a presentation on using both static analysis and model checking for finding errors in programs. A companion paper to this presentation is included in the proceedings.But, what does the future hold? Can we analyze real programs? Will software model checking ever be push-button? Do we (only) care about finding errors? Can we leverage SAT technology like hardware model checking does? Hopefully we answered some of these questions and more at the 2003 Workshop on Software Model Checking. Our intention for this second workshop was to help provide a springboard for the next phase of development in software model checking.The call for papers resulted in 18 submissions, of which 8 were selected for presentation. The selection process consisted of each paper receiving 3 reviews, followed by a virtual Program Committee meeting. This year the selection process was particularly hard, due to the high level of the submissions, and we are very grateful to the PC and the additional reviewers for their efforts in this regard.Program Committee

Byron Cook (Microsoft)

David Dill (Stanford University)

Patrice Godefroid (Bell Laboratories, Lucent Technologies)

Susanne Graf (Verimag)

Gerard Holzmann (NASA/JPL Laboratory for Reliable Software)

Radu Mateescu (INRIA Rhône-Alpes/VASY)

Scott Stoller (State University of New York at Stony Brook)

Willem Visser (RIACS/NASA Ames Research Center)

Additional Reviewers: Aurore Collomb, Shuvendu Lahiri, Frederic Lang, Jacob Lichtenberg, Kedar Namjoshi and Wendelin SerweWe would also like to thank Microsoft Research for generously providing financial support and the CAV 2003 organizers for their help in organizing the workshop.     

2009 CAV award announcement

The 2009 CAV (Computer-Aided Verification) award was presented to seven individuals who made major advances in creating high-performance Boolean satisfiability solvers. This annual award recognizes a specific fundamental contribution or series of outstanding contributions to the CAV field.     

变风量系统空调房间建模与特性参数估算

讨论了变风量空调系统的基本原理 ,根据定风量方式下空调房间的数学模型和特性参数的估算公式 ,结合变风量系统的特点 ,推导出变风量方式下空调房间的数学模型以及两种送风方式下特性参数的关系 ,对研究变风量系统的协调控制问题具有重要的理论意义和明显的实用价值。     

Determinants of software piracy under risk aversion: a model with empirical evidence

This paper studies the determinants of software piracy in world economies from a risk avoidance perspective. A risk aversion model for the commercialization of pirated software is developed to account for behavioral elements of risk and uncertainty avoidance among countries’ software pirates (i.e., counterfeiters and suppliers) and test empirically for the effects of country characteristics on piracy levels. Panel regression analysis is conducted to identify the determinants of software piracy using this model on a data set of 87 countries during 2007–2011. The empirical results confirm those obtained in prior research (e.g., the inverted U-shaped relationship between GDP per capita and piracy rates) but divulge that the behavioral-country component capturing the attitudes towards risk of software pirates improves the explanatory power of the statistical regressions after controlling for country performance and institutional factors. We also show that human development and good country governance reduce piracy rates. Besides providing support for our risk aversion-based piracy model and hinting at the need to consider population behavior in policy-making, these findings underline the relevance of human development and country institutions in explaining software piracy rates.     

An impact study of integrating connected automated vehicles with conventional traffic

Connected and automated vehicles (CAVs) promise to change the transportation landscape with safer, faster and more energy-efficient mobility. However 100% CAV penetration may never be achieved, raising the question of how to ensure a productive co-existence of CAVs with conventional vehicles. In this paper, we address the problem of optimally controlling CAVs under mixed traffic conditions where both CAVs and human-driven vehicles (non-CAVs) travel on the roads. We specifically consider problems with such mixed traffic crossing an intersection without using explicit traffic signaling, the objective being to minimize energy consumption subject to a throughput maximization requirement while guaranteeing safety constraints. The impact of CAVs on overall energy consumption is investigated under different traffic scenarios as a function of the CAV penetration rate (i.e., the fraction of CAVs relative to all vehicles). Performance under traffic light control is used as a baseline for this study. Results are validated through simulation using MATLAB and VISSIM. The results indicate that the energy efficiency improvement becomes more significant as the CAV penetration rate increases, while the significance diminishes as traffic becomes heavier.     

Design and results of the 2nd annual satisfiability modulo theories competition (SMT-COMP 2006)

The Satisfiability Modulo Theories Competition (SMT-COMP) arose from the SMT-LIB initiative to spur adoption of common, community-designed formats, and to spark further advances in satisfiability modulo theories (SMT). The first SMT-COMP was held in 2005 as a satellite event of CAV 2005. SMT-COMP 2006 was held August 17–19, 2006, as a satellite event of CAV 2006. This paper describes the rules and competition format for SMT-COMP 2006, the benchmarks used, the participants, and the results.     

Offline enforcement of contracts for high‐performance computing

Design by contract is a well‐known software design methodology which enhances the quality of software through assertions expressed at the interface level. The overhead averse nature of High‐Performance Computing (HPC) applications often precludes the use of design by contract due to its potential overhead, especially when handling the large data sizes common in HPC. Our approach is to reduce the overhead of design by contract, by postponing (or offloading) across time and space the enforcement of contracts. We argue that the semantic implications of this approach are not significant, while leading to a large potential overhead reduction. A reduced overhead strategy to contract implementation may be necessary for a wider acceptance of this useful software engineering primitive. We apply our approach to contracts developed for software components based on the CCA (Common Component Architecture) model, which targets HPC applications. Copyright © 2011 John Wiley & Sons, Ltd.     

软件产品线可变性建模技术系统综述

软件产品线是实现大规模的软件复用、保证高质量的新产品开发的最佳实践.软件产品线的关键问题是如何进行可变性管理,并基于可变性管理实现软件核心资产的复用.软件产品线可变性建模是可变性管理的关键技术,实现产品家族成员的共性和可变性的描述.可变性建模涉及软件开发的全生命周期,在领域工程和应用工程中,尤其是在产品构建过程中,起到重要的作用.从众多的建模技术中选择合适的建模技术是十分困难的,在软件产品线领域中开展了可变性建模技术的系统综述,按照系统综述的方法对可变性建模技术进行了系统总结,根据系统综述规则,选取了从1990 年~2011 年发表的论文进行综述.讨论了系统综述的研究成果,从可变性建模方法分类、重要可变性建模技术对比等方面进行深入的探讨,为建模人员和研究人员对可变性建模技术的选择和研究提供支持.最后分析了可变性建模技术的研究趋势,并对可变性建模技术有待深入的研究难点和发展趋势进行了展望.     

Large‐signal modeling methodology for GaN HEMTs for RF switching‐mode power amplifiers design

A large‐signal model for GaN HEMT transistor suitable for designing radio frequency power amplifiers (PAs) is presented along with its parameters extraction procedure. This model is relatively easy to construct and implement in CAD software since it requires only DC and S‐parameter measurements. The modeling procedure was applied to a 4‐W packaged GaN‐on‐Si HEMT, and the developed model is validated by comparing its small‐ and large‐signal simulation to measured data. The model has been employed for designing a switching‐mode inverse class‐F PA. Very good agreement between the amplifier simulation and measurement shows the validity of the model. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

CADP 2011: a toolbox for the construction and analysis of distributed processes

CADP (Construction and Analysis of Distributed Processes) is a comprehensive software toolbox that implements the results of concurrency theory. Started in the mid-1980s, CADP has been continuously developed by adding new tools and enhancing existing ones. Today, CADP benefits from a worldwide user community, both in academia and industry. This paper presents the latest release, CADP 2011, which is the result of a considerable development effort spanning the last five years. The paper first describes the theoretical principles and the modular architecture of CADP, which has inspired several other recent model checkers. The paper then reviews the main features of CADP 2011, including compilers for various formal specification languages, equivalence checkers, model checkers, compositional verification tools, performance evaluation tools, and parallel verification tools running on clusters and grids. Finally, the paper surveys some significant case studies.     

Flex‐eWare: a flexible model driven solution for designing and implementing embedded distributed systems

The complexity of modern embedded systems increases as they incorporate new concerns such as distribution and mobility. These new features need to be considered as early as possible in the software development life cycle. Model driven engineering promotes an intensive use of models and is now widely seen as a solution to master the development of complex systems such as embedded ones. Component‐based software engineering is another major trend that gains acceptance in the embedded world because of its properties such as reuse, modularity, and flexibility. This article proposes the Flex‐eWare component model (FCM) for designing and implementing modern embedded systems. The FCM unifies model driven engineering and component‐based software engineering and has been evaluated in several application domains with different requirements: wireless sensor networks, distributed client/server applications, and control systems for electrical devices. This approach highlights a new concept: flexibility points that arise at several stages of the development process, that is, in the model (design phase), in the execution platform, and during the execution itself. This flexibility points are captured with model libraries that can extend the FCM. Copyright © 2011 John Wiley & Sons, Ltd.     

A Cognitive Model for Meetings in the Software Development Process

Meetings are at the heart of the software development process (SDP) and can be of different types. The present article first proposes an abstract cognitive model for meetings, which represents how different types of meetings are affected by cognitive activities at different stages within the SDP. Second, and based on the analysis of meetings at different stages of SDP, it proposes the removal of such meetings from some of the stages within the program by using a cognitive evaluation model for meetings and their replacement, instead, with information and communication technology tools and techniques by means of a cognitive evaluation model. The abstract cognitive model and the evaluation model are validated empirically through experimentation, carried out through a detailed analysis of a target group composed of information technology professionals. © 2011 Wiley Periodicals, Inc.