The role of model checking in software engineering

Model checking is a formal verification technique. It takes an exhaustively strategy to check hardware circuits and network protocols against desired properties. Having been developed for more than three decades, model checking is now playing an important role in software engineering for verifying rather complicated software artifacts.This paper surveys the role of model checking in software engineering. In particular, we searched for the related literatures published at reputed conferences, symposiums, workshops, and journals, and took a survey of (1) various model checking techniques that can be adapted to software development and their implementations, and (2) the use of model checking at different stages of a software development life cycle. We observed that model checking is useful for software debugging, constraint solving, and malware detection, and it can help verify different types of software systems, such as object- and aspect-oriented systems, service-oriented applications, web-based applications, and GUI applications including safety- and mission-critical systems.The survey is expected to help human engineers understand the role of model checking in software engineering, and as well decide which model checking technique(s) and/or tool(s) are applicable for developing, analyzing and verifying a practical software system. For researchers, the survey also points out how model checking has been adapted to their research topics on software engineering and its challenges.     

铂电阻Pt100特性数学模型

为了满足自动检测和智能仪表的需要,提出了一种基于余弦基神经网络的传感器特性建模算法,提出了该余弦基神经网络算法的收敛定理,并以铂电阻Pt100为例给出了传感器特性数学模型的建模步骤。计算机仿真结果表明了该算法在传感器特性建模过程中的有效性和优异性能。     

基于角色和信誉的跨域信任管理模型研究

目前,基于角色的信任管理及基于信誉的信任管理模型都存在安全缺陷。本文将基于角色的信任管理和基于信誉的信任管理相结合,提出了一种改进的信任管理模型,以提高跨域系统的安全性。     

The role of temporal parameters in a thalamocortical model of analogy

How multiple specialized cortical areas in the brain interact with each other to give rise to an integrated behavior is a largely unanswered question. This paper proposes that such an integration can be understood under the framework of analogy and that part of the thalamus and the thalamic reticular nucleus (TRN) may be playing a key role in this respect. The proposed thalamocortical model of analogy heavily depends on a diverse set of temporal parameters including axonal delay and membrane time constant, each of which is critical for the proper functioning of the model. The model requires a specific set of conditions derived from the need of the model to process analogies. Computational results with a network of integrate and fire (IF) neurons suggest that these conditions are indeed necessary, and furthermore, data found in the experimental literature also support these conditions. The model suggests that there is a very good reason for each temporal parameter in the thalamocortical network having a particular value, and that to understand the integrated behavior of the brain, we need to study these parameters simultaneously, not separately.     

The role of trust in e-commerce relational exchange: A unified model

Recently, studies of B2C e-commerce have used intention theory to understand the role of trust of Internet transactions but most have investigated only a component of e-commerce (e.g., initial adoption or continuance) and neglected the role of good relations with the consumer in ensuring a successful sustained relationship. Therefore, a model that went beyond intention and included key relational concepts (satisfaction, value, loyalty, etc.) was developed. Trust and its components are a major part of this model, which was based on strong theoretical foundations. Fifteen hypotheses were formulated. Data on the constructs were collected from 420 respondents and analyzed using elliptical re-weighted least squares as the estimation method to test model validity and the hypotheses. An additional relationship between satisfaction and customer loyalty was investigated. Implications for researchers and practitioners are discussed.     

The role of intermediaries in electronic marketplaces: developing a contingency model

Abstract. Early research in electronic markets seemed to suggest that e‐ commerce transactions would result in decreased costs for buyers and sellers alike, and would therefore ultimately lead to the elimination of intermediaries from electronic value chains. However, a careful analysis of the structure and functions of electronic marketplaces reveals a different picture. Intermediaries provide many value‐adding functions that cannot be easily substituted or ‘internalized’ through direct supplier–buyer dealings, and hence mediating parties may continue to play a significant role in the e‐commerce world. In this paper we provide an analysis of the potential roles of intermediaries in electronic markets and we articulate a number of hypotheses for the future of intermediation in such markets. Three main scenarios are discussed: the disintermediation scenario, in which market dynamics will favour direct buyer–seller transactions; the reintermediation scenario, in which traditional intermediaries will be forced to differentiate themselves and re‐emerge in the electronic marketplace; and the cybermediation scenario, in which wholly new markets for intermediaries will be created. The analysis suggests that the likelihood of each scenario dominating a given market is primarily dependent on the exact functions that intermediaries play in each case. A detailed discussion of such functions is presented in the paper, together with an analysis of likely outcomes in the form of a contingency model for intermediation in electronic markets.     

The centralized intake model for drug abuse treatment: The role of computerized data management

Several large research programs are underway that evaluate the centralized intake model for drug abuse treatment. In this model, the drug abuse treatment facilities in a city do not operate independently; their efforts are coordinated through a small number of intake centers, which handle all patient intake and data management activities. The success of such a coordinated approach to drug abuse treatment depends in large measure upon an adequate flow of patient information. For that reason, the centralized intake model brings new challenges for the field of computerized data management. The present article describes the management information system that is being used in a large research program called the District of Columbia Initiative (DCI). The methods of this system could be applied in cities where the centralized intake model for drug abuse treatment is adopted.     

The AI potential of model management and its central role in decision support

The paper stresses the general idea that ‘intelligence’ may be viewed to a great extent as the ability to model relevant parts of reality and to draw relevant conclusions from such models. Consequently, future software systems should be able to adequately handle a significant body of models for specific domains together with associated algorithmic tools. With respect to decision making and decision support, which require a high degree of cognitive sophistication, this leads to the quest for integrating into DSS results from model-oriented research in fields such as stochastics, statistics, decision theory, operations research and business applications. Based on such modelling capabilities, a DSS should be able to take a more active, normatively based role in aiding a decision maker. This kind of support requires strong interactive capabilities, driven by online computätional results and based on parallel problem exploration with partial models, incomplete information and robust solution methods. Additionally, such multi-level simultaneous use of a great number of interdependent models and associated algorithmic tools requires in itself an increased sophistication in model management. This should include a dynamic, performance-driven and adaptive use of the available algorithmic tools which actively addresses issues possibly overlooked by the user. In establishing this kind of sophistication, extensive use of available AI techniques will be in order. The paper tries to establish some guidelines for advanced system designs aiming at such sophisticated, highly integrative solutions.     

支持动态角色切换的RBAC模型

动态角色切换是信息系统依据用户属性改变而部分或整体改变用户-角色指派的一种自动授权机制。本文将动态角色切换引入到RBAC96模型,论述了动态角色切换的各种形态、不同切换间的相互关系及模型实现。基于动态角色切换,系统可以自动处理触发角色切换条件而引起的用户-角色指派变更问题,整个过程无须人工参与,减轻了系统管理员的工作负担,提高了授权管理的效率与安全性。     

融合角色机制的强制访问控制模型

传统的BLP模型能够提供良好的信息保密机制,但是由于过于严苛的约束规则造成其在可用性方面存在着一定的缺陷,RBAC模型提供了很好的可用性,但在信息安全保证方面存在一定的不足.从分析BLP模型和RBAC模型入手,通过引入角色安全标签机制,提出了一个BLP和RBAC的融合机制,形成了一个全新的信息模型RBLP.RBLP模型不但能够提供良好的信息保密机制,同时有着很好的可用性.     

基于属性和角色的访问控制模型

针对Web资源访问控制对访问控制策略灵活性、动态性以及权限管理便捷性的需求,提出一种基于属性和角色的访问控制模型ACBAR,对模型中的元素、关系及规则进行了形式化定义。给出了ACBAR模型的应用实例及相关访问控制策略,并对模型的安全性和应用复杂度进行了分析。ACBAR模型在遵循最小特权和职责分离等安全原则的基础上,相对于RBAC模型有效降低了角色管理的复杂度,支持灵活、动态的Web资源访问控制策略。     

基于角色和规则引擎的UCON应用模型

UCON是一种基于属性的下一代访问控制模型,但其高度抽象,难于直接应用,为此提出了一种基于角色和规则引擎的UCON应用模型UCON-ABRR.该模型通过引入角色这一属性,便于实现基于角色的用户管理;并基于规则引擎来制定访问规则和实施访问控制策略,不仅支持UCON的两个重要特征:属性易变性和决策过程连续性,而且具有很好的可操作性.该模型具有通用性,将其应用于云存储场景中,达到了预期的访问控制效果.     

基于角色理论的RBAC96模型改进

在分析RBAC96模型的基础上,从角色概念及角色间关系的角度分析其不明确之处;通过角色理论中的可计算角色模型,改进RBAC96模型,使其具有更好的扩展性。     

100MHz的440BX芯片组

主要介绍Ｉｎｔｅｌ公司新近发布的支持１００ＭＨｚ外频的４４０ＢＸＡＧＰｓｅｔ，同时详细分析了在使用内建该芯片组的主板时必须注意的一些问题。     

Device-physics-based analytical model for SET pulse in sub-100 nm bulk CMOS Process

Through revising the process of charge collection for reversed drain-bulk junction,a bias-dependent SPICE model is proposed which includes the bipolar amplification effect that cannot be ignored in PMOS.The model can capture the plateau effect,and produce current and voltage pulse shapes and widths that are consistent with TCAD simulation.Considering the case of connecting load,it is still valid.For combination and sequential logic circuits,the SET pulsewidths and LET upset threshold from SPICE model are consistent with TCAD simulations.     

A study of real-time and 100 billion agents simulation using the Boids model

In high-performance computing of multi-agent systems, there often exists a load imbalance that slows down the calculation. In this paper, we discuss the parallelization of the Boids model for simulating a swarm intelligence. We apply the multi-level hierarchy of parallelism to the Boids model to mitigate the load-imbalance problem. To eliminate numerical errors due to parallelization, we apply pseudo-quadruple arithmetic. The parallel performance is evaluated on three major architectures, including many-core processors on an x86-based server with GPUs, and the Earth Simulator. The parallelization can decrease the negative effects of a load imbalance to almost zero in a simulation of 50 million agents. In addition, the parallelization guarantees the reproducibility of the results in a sequential execution. The strong scaling shows the potential to complete a simulation in real-time on the Earth Simulator. In addition, the weak scaling shows the ability to calculate 100 billion agents within a reasonable amount of time.