基于OCL文法的测试用例自动生成方法研究

随着软件测试技术的飞速发展,很多自动生成和执行测试用例的方法的技术已经发展起来。对于自动生成测试用例的约束的形式化定义也有很多方法,其中,对象约束语言(OCL)就是其中最具代表性的。OCL能够弥补UML模型的不足,精确地定义约束条件。本文将着重介绍一种从OCL文法解析到约束条件分离的方法的研究结果,通过与OCL文法比较,解析输入的OCL文本,提取OCL表达式,构建约束条件树,实现约束条件分离,最终实现测试用例集的自动生成。     

基于OCL文法的测试用例自动生成方法研究

随着软件测试技术的飞速发展，很多自动生成和执行测试用例的方法的技术已经发展起来。对于自动生成测试用例的约束的形式化定义也有很多方法，其中，对象约束语言（OCL）就是其中最具代表性的。OCL能够弥补UML模型的不足，精确地定义约束条件。本文将着重介绍一种从OCL文法解析到约束条件分离的方法的研究结果，通过与OCL文法比较，解析输入的OCL文本，提取OCL表达式，构建约束条件树，实现约束条件分离，最终实现测试用例集的自动生成。     

On the expressiveness of MTL in the pointwise and continuous semantics

We show that the pointwise version of the logic MTL is strictly less expressive than the continuous version, over finitewords. The proof is constructive in that we exhibit a timed language, which is definable in the continuous semantics but is not definable in the pointwise semantics.     

OCL 1.4/5 vs. 2.0 Expressions Formal semantics and expressiveness

A type inference system and a big-step operational semantics for expressions of the Object Constraint Language (OCL), the declarative and navigational constraint language for the Unified Modeling Language (UML), are provided; the account is mainly based on OCL 1.4/5, but also includes the main features of OCL 2.0. The formal systems are parameterised in terms of UML static structures and UML object models, which are treated abstractly. It is proved that the operational semantics satisfies a subject reduction property with respect to the type inference system. Proceeding from the operational semantics and providing a denotational semantics, pure OCL 2.0 expressions are shown to exactly represent the primitive recursive functions, whereas pure OCL 1.4/5 expressions are Turing complete.     

带OCL约束的多态路径测试线索生成方法

统一建模语言(UML)无法精确描述系统模型,只能从某一层面描述系统信息,从而导致基于UML模型的多态测试不完备。为此,提出一种带OCL约束的多态路径测试线索生成方法。通过在类图中加入OCL约束信息,考虑类图中多态性对测试的影响,结合UML类图、状态图及协作图,设计并构造OCL约束下包含多态和状态信息的消息间受限控制流图(MRCFG),应用唯一MRCFG路径覆盖准则生成测试线索。通过建立原型工具自动生成包含多态信息的测试线索,从而证明该方法提高了测试的自动化程度,并且生成的多态测试线索更完备。     

OCL数据类型到B形式化规约的转换

研究了UML模型到B形式化规约的转换。提出了一套从OCL数据类型及定义在这些数据类型上的操作到BAMN的转换规则。OCL的Boolean类型和Integer类型分别对应于B中的BOOL类型和Z类型;OCL中的String类型需用B抽象机器重新定义新的数据类型Char_TYPE和String_TYPE来进行规约;OCL中的REAL类型采用B中的记录表达式进行近似模拟;OCL中的Collection类型（包括Set,Orderedset,Bag,Sequence）用B语言中的set,sequence,tree等进行近似模拟。     

Validation of protocols with temporal constraints

Reachability analysis is the most popular and most used method in protocol validation. It consists in constructing a graph called a reachability graph, describing communication of machines exchanging messages through FIFO channels. The states and structure of this graph are then analysed according to given properties to validate the related communication protocol. In this paper, we deal with a generalization of reachability analysis to take into account quantitative temporal constraints in protocol validation. A temporal reachability graph is designed, and we show how it can be used to analyse new general properties of communication protocols submitted to temporal constraints.     

Specification of temporal properties with OCL

The Object Constraint Language (OCL) is widely used to express static constraints on models and object-oriented systems. However, the notion of dynamic constraints, controlling the system behavior over time, has not been natively supported. Such dynamic constraints are necessary to handle temporal and real-time properties of systems.In this paper, we first add a temporal layer to the OCL language, based syntactically on Dwyer et al.'s specification patterns. We enrich it with formal scenario-based semantics and integrate it into the current Eclipse OCL plug-in. Second, we translate, with a compositional approach, OCL temporal properties into finite-state automata and we connect our framework to automatic test generators. This way, we create a bridge linking model driven engineering and usual formal methods.     

Explicit modeling of semantics associated with composite states in UML statecharts

UML statecharts are used for describing dynamic aspects of system behavior. The work presented here extends a general Petri net-based methodology to support formal modeling of UML statecharts. The approach focuses on the specific task of generating explicit transition models associated with the hierarchical structure of statechart. We introduce a state-transition notation to serve as an intermediate model for conversion of UML statecharts, and in particular, the complexity of composite states, to other target specifications. By defining a process for deriving, from UML statecharts, a state-transition notation that can serve as an intermediate state machine model, we seek to deepen understanding of modeling practices and help bridge the gap between model development and model analysis. This work covers all of the primary issues associated with the hierarchical structure of composite states, including entry and exit transitions, transition priorities, history states, and event dispatching. Thus, the results provide an important step forward toward the goal of modeling increasingly complex semantics of UML statecharts. This material is based upon work supported by the U.S. Army Research Office under grant number DAAD19-01-1-1-0672, and the U.S. National Science Foundation under grant number CCR-9988168.     

A method for describing the syntax and semantics of UML statecharts

In this article we present a method for describing the language of UML statecharts. Statecharts are syntactically defined as attributed graphs, with well-formedness rules specified by a set of first-order predicates over the abstract syntax of the graphs. The dynamic semantics of statecharts is defined by Abstract State Machines parameterized with syntactically-correct attributed graphs. The presented approach covers many important constructs of UML statecharts, including internal, completion, interlevel and compound transitions as well as history pseudostates. It also contains strategies to handle state entry/exit actions, state activities, synch states and choice pseudostates.     

对象约束语言对武器系统效能评估指标体系的描述与验证

武器系统效能评估是武器系统设计过程中的重要环节,效能评估指标体系作为效能评估的前提和基础,其描述的精确性将直接影响武器系统效能评估的结果.针对武器系统的设计过程,提出了一种效能评估指标体系的描述方法,即元模型描述方法;引入统一建模语言(UML)规范的一部分对象约束语言(OCL)对其进行精确描述.最后,通过实验验证了OCL描述的正确性,为武器系统设计过程中的效能评估提供依据.     

UML类图的形式化及分析

统一建模语言(UML)是一种通用的图形化建模语言,在面向对象系统的分析和设计中,它已成为事实上的工业标准。但是UML不是形式化的建模语言,缺乏精确的语义描述,因此会导致一些问题。Z是一种广泛使用的形式化规约语言,Z适合用来精确地表示模型的语法和语义。文章采用Z符号来表示UML类图的组成元素的语法和语义及其映射关系,最后对UML类图的一些性质进行分析和验证。     

Range and Roots: Two common patterns for specifying and propagating counting and occurrence constraints

We propose Range and Roots which are two common patterns useful for specifying a wide range of counting and occurrence constraints. We design specialised propagation algorithms for these two patterns. Counting and occurrence constraints specified using these patterns thus directly inherit a propagation algorithm. To illustrate the capabilities of the Range and Roots constraints, we specify a number of global constraints taken from the literature. Preliminary experiments demonstrate that propagating counting and occurrence constraints using these two patterns leads to a small loss in performance when compared to specialised global constraints and is competitive with alternative decompositions using elementary constraints.     

Maintaining constraints of UML models in distributed collaborative environments

Constraint maintenance plays an important role in keeping the integrity and validity of UML models in embedded software design. While constraint maintenance capabilities are reasonably adequate in existing UML modeling applications, little work has been done to address the distributed constraint maintenance issue in multi-user collaborative modeling environments. The nature of the issue is to maintain constraint consistently across distributed sites in a collaborative modeling environment in the face of concurrency. In this paper, we propose a novel solution to this issue, which can retain the effects of all concurrent modeling operations even though they may cause constraint violations. We further contribute a distributed constraint maintenance framework in which the solution is encapsulated as a generic engine that can be mounted in a variety of single-user UML modeling applications to support collaborative UML modeling and distributed constraint maintenance in embedded software design processes. This framework has been implemented in a prototype distributed collaborative UML modeling application CoRSA.     

Decentralized multi-robot allocation of tasks with temporal and precedence constraints

Abstract

We present an auction-based method for a team of robots to allocate and execute tasks that have temporal and precedence constraints. Temporal constraints are expressed as time windows, within which a task must be executed. The robots use our priority-based iterated sequential single-item auction algorithm to allocate tasks among themselves and keep track of their individual schedules. A key innovation is in decoupling precedence constraints from temporal constraints and dealing with them separately. We demonstrate the performance of the allocation method and show how it can be extended to handle failures and delays during task execution. We leverage the power of simulation as a tool to analyze the robustness of schedules. Data collected during simulations are used to compute well-known indexes that measure the risk of delay and failure in the robots’ schedules. We demonstrate the effectiveness of our method in simulation and with real robot experiments.     

Formal semantics,modular specification,and symbolic verification of product-line behaviour

Formal techniques for specifying and verifying Software Product Lines (SPL) are actively studied. While the foundations of this domain recently made significant progress with the introduction of Featured Transition Systems (FTSs) and associated algorithms, SPL model checking still faces the well-known state explosion problem. Moreover, there is a need for high-level specification languages usable in industry. We address the state explosion problem by applying the principles of symbolic model checking to FTS-based verification of SPLs. In order to specify properties on specific products only, we extend the temporal logic CTL with feature quantifiers. Next, we show how SPL behaviour can be specified with fSMV, a variant of SMV, the specification language of the industry-strength model checker NuSMV. fSMV is a feature-oriented extension of SMV originally introduced by Plath and Ryan. We prove that fSMV and FTSs are expressively equivalent. Finally, we connect these results to a NuSMV extension we developed for verifying SPLs against CTL properties.     

基于时序逻辑的UML2.0通信图语义研究

UML2.0通信图可以表示对象之间的交互,很适合用于对系统的交互行为建模,但由于UML缺乏精确语义,使得难以对其所表示的系统行为进行分析和验证.XYZ/E是可执行线性时序逻辑语言,既可描述系统的静态语义和动态语义.在定K.UML2.0通信图的形式化语法的基础上,给出了通信图的XYZ/E时序逻辑语义,为进一步的系统分析和验证提供了形式化基础.     

具有时空约束的TRBAC模型在OA中的应用

本文提出了一个基于TRBAC（Task—Kole Based Access Contr01）具有时空约束的工作流授权模型TSC—TRBAC（Temporarily-SpatiallyConstrained Task—RoleBased Access Contr01）。所谓时空约束即用户执行任务的时候,不仅受到时间约束,而且还受到空间限制,包括对物理空间和逻辑空间的限制,这使得工作流的安全性得以保证。通过将该模型应用到具体的系统中,表明了该模型的可行性。