支持抽象解释的静态分析方法的形式化体系研究

在安全关键领域中,如何保证软件的安全性已经成为了一个广受关注的重要课题。静态程序分析是一类十分有效的程序自动化验证方法。基于抽象解释的静态分析技术在验证软件的非功能性安全属性上表现十分突出。可配置程序分析(Configurable Program Analysis,CPA)是一种通用静态分析方法形式化体系,旨在用一种形式化体系对静态分析的分析阶段进行建模。使用CPA对基于抽象解释的静态分析进行建模,给出如何使用CPA形式化体系描述基于抽象解释的静态分析,给出了从待分析程序到CPA形式化体系的转换规则;提供了一种在安全关键性领域中的软件正确性自动验证方法,为基于抽象解释的静态分析工具的实现提供了一种可行方案。     

基于UML的面向C4ISR能力需求分析的对象建模语言

军事电子信息系统是一种典型的大规模复杂系统,如何获取这种复杂系统的需求仍然是一个难题。提出了一种新的能力需求分析方法。该方法从领域概念化入手,构造了C4ISR能力概念化的元本体;利用UML元层扩展机制,提出了一种用于定义C4ISR能力概念的对象建模语言,并给出了该语言的抽象语法和详细语法,利用OWL DL定义了形式语义。最后以一个C4ISR体系结构仿真建模为案例,说明了该方法的有效性和可用性。     

A Real-Time Discrete Event System Specification Formalism for Seamless Real-Time Software Development

We present a time domain extension of the hierarchical and modular discrete event specification (DEVS) formalism. This extension is important for establishing a seamless real-time software development framework. Formalisms help describe a system unambiguously. If formal models are implemented without any consistent frameworks, however, it is hard to guarantee that there is no semantic gap between models and codes. Real-Time DEVS, named RTDEVS, is an extension of DEVS that can be characterized in three perspectives: the real time execution of models, the addition of time interval functions, and the activity specification for each state. After analyzing a system, the framework based on RTDEVS helps to expand each model of the system for executing in a real-time environment. In order to support the RTDEVS formalism, we propose abstract executive concepts based on the abstract simulator concepts of the DEVS formalism. Also, we implement an RTDEVS execution engine, named DEVS Executive, which runs on real-time Mach.     

PAMS: A Domain-specific Knowledge-based Parallel Machine Scheduling System

Abstract: To overcome the inefficiency of domain independent tools, a domain-specific knowledge-based shell for parallel machine scheduling problems, PAMS (PArallel Machine Scheduling System), is proposed. PAMS has the following features; mixed knowledge representation, two-stage status-driven control strategy, conflict resolution using domain theory, domain-specific syntax and primitive operators, interface with database, domain-specific input/output interface, interactive scheduling capability, built-in heuristic knowledge, multiple levels of schedule, and expansibility of the domain. A prototype of PAMS, PAMS-1, is developed using C-language on a supermicrocomputer, and the performance of PAMS-1 is evaluated. The results show that the PAMS-1 performs very well from various perspectives.     

基于SHML的CPS行为建模及仿真

信息物理融合系统（cyber-physical systems，简称CPS）是深度融合了计算进程和物理进程的统一体，是集计算、通信与控制于一体的下一代智能系统，具有广阔的应用前景.CPS的行为具有混成性、随机性等特征，建模及仿真CPS的动态行为对于开发高质量的CPS系统至关重要.但是目前缺乏面向CPS的领域建模方法及建模CPS的领域建模语言，也迫切需要支持仿真CPS领域模型的仿真工具.针对以上问题，提出一种面向CPS领域的随机混成建模语言（stochastic hybrid modeling language，简称SHML）以支持建模CPS系统的行为.首先，根据CPS的领域特征定义了SHML的元模型作为其抽象语法，并定义了SHML的具体语法和操作语义；其次，基于GEMOC框架实现了SHML的可视化建模工具.此外，集成GEMOC的序列化执行引擎和Scilab的连续行为仿真引擎，实现仿真CPS的混成行为.提出了一种面向CPS领域的建模及仿真方法，设计并实现了一个集成的面向CPS行为的建模与仿真平台，为CPS的建模及仿真提供了一种有效的方法及工具支撑.     

Synchronization of abstract and concrete syntax in domain-specific modeling languages

Modern domain-specific modeling (DSM) frameworks provide refined techniques for developing new languages based on the clear separation of conceptual elements of the language (called abstract syntax) and their graphical visual representation (called concrete syntax). This separation is usually achieved by recording traceability information between the abstract and concrete syntax using mapping models. However, state-of-the-art DSM frameworks impose severe restrictions on traceability links between elements of the abstract syntax and the concrete syntax. In the current paper, we propose a mapping model which allows to define arbitrarily complex mappings between elements of the abstract and concrete syntax. Moreover, we demonstrate how live model transformations can complement mapping models in providing bidirectional synchronization and implicit traceability between models of the abstract and the concrete syntax. In addition, we introduce a novel architecture for DSM environments which enables these concepts, and provide an overview of the tool support.     

Intelligent non-visual navigation of complex HTML structures

This paper provides an overview of a project aimed at using knowledge-based technology to improve accessibility of the Web for visually impaired users. The focus is on the multi-dimensional components of Web pages (tables and frames); our cognitive studies demonstrate that spatial information is essential in comprehending tabular data, and this aspect has been largely overlooked in the existing literature. Our approach addresses these issues by using explicit representations of the navigational semantics of the documents and using a domain-specific language to query the semantic representation and derive navigation strategies. Navigational knowledge is explicitly generated and associated to the tabular and multi-dimensional HTML structures of documents. This semantic representation provides to the blind user an abstract representation of the layout of the document; the user is then allowed to issue commands from the domain-specific language to access and traverse the document according to its abstract layout. Published online: 6 November 2002     

基于Linux的嵌入式GUI系统设计分析

随着技术的发展,嵌入式系统要求使用图形化界面便于用户的操作。本文从系统体系结构出发,讨论了GUI设计中涉及的几个重要方面,包括消息循环、多窗口管理、控件／控件类和输入／输出抽象层的基本概念和设计要点。     

Composing domain-specific design environments

Domain-specific integrated development environments can help capture specifications in the form of domain models. These tools support the design process by automating analysis and simulating essential system behavior. In addition, they can automatically generate, configure, and integrate target application components. The high cost of developing domain-specific, integrated modeling, analysis, and application-generation environments prevents their penetration into narrower engineering fields that have limited user bases. Model-integrated computing (MIC), an approach to model-based engineering that helps compose domain-specific design environments rapidly and cost effectively, is particularly relevant for specialized computer-based systems domains-perhaps even single projects. The authors describe how MIC provides a way to compose such environments cost effectively and rapidly by using a metalevel architecture to specify the domain-specific modeling language and integrity constraints. They also discuss the toolset that implements MIC and describe a practical application in which using the technology in a tool environment for the process industry led to significant reductions in development and maintenance costs     

嵌入式Linux下Qt/Embedded的应用

随着嵌入式系统的发展,用于实现与用户交流功能的嵌入式GUI成为研究中的一个重点。嵌入式Linux下,如果图形界面接口采用的是Qt/Embedded,则必须采用Linux的帧缓冲设备来处理相关的底层命令。帧缓冲是Linux为图形设备提供的一个抽象接口,是Qt/Embedded的底层图形引擎。文中介绍了Linux帧缓冲设备驱动程序框架,基于三星公司的S3C2410x处理器的开发平台,系统给出了嵌入式图形界面GUI的移植,包括编译环境的建立,编译参数的设置等。     

基于运行监测的图形用户界面自动化测试模型

为提高GUI自动化测试的覆盖率、故障定位的速率和精度,以及检测由于时空变化导致的空间错误引起的故障,建立基于运行监测的GUI自动化测试模型。模型将GUI分为窗口框架层、界面元素层、功能结构层和运行记录层四层。窗口框架层描述GUI所有窗口,界面元素层描述用户输入,功能结构层提出功能覆盖准则,运行记录层通过插桩记录代码动态监测软件每一次执行时路径和各个窗口的运行状态,从而提高测试的覆盖率,并根据运行记录中窗口的总执行次数和正确的执行次数为可靠性计算提供依据。由于监测代码的运行情况,因此故障能够定位到代码级,提高故障定位的精度和速率。最后以记事本程序为例验证了模型的有效性。     

GUI抽象描述模型研究

图形用户界面（GUI）是各种计算机应用的一个重要组成部分。但是越来越多的缟程语言和GUI工具包使得开发跨平台的GUI也变得越来越繁琐。同时,日趋庞大和复杂的数据,也迫使开发者在维护GUI相关数据方面付出更多的努力。本文从分析MVC设计模式入手,力图从更高的层次上对GUI及其相关数据的描述模型进行归纳和抽象,提出并形式化描述了一种GUI抽象描述模型,基于该模型的GUI数据建模算法和绑定模型。最后简单介绍了该描述模型基于XML的实现语言——GUI XML。     

Designing ontologies for higher level fusion

The purpose of higher level fusion is to produce contextual understanding of the states of the environment and prediction of their impact in relation to specific goals of decision makers. One of the main challenges of designing higher level fusion processes is to provide a formal structure of domain-specific types of entities, attributes, situations, and the relations between them for reasoning about situations and threats. This paper presents an attempt at confronting this challenge by describing a process for building formal ontologies that combines a top–down philosophical perspective (from the most abstract levels to domain-specific levels) with a bottom-up application-based perspective (from domain-specific levels to the most abstract levels). The main focus of this paper is to provide a conceptual framework for formally capturing various sorts of complex relation-types, which can serve as a means for a more thorough decomposition of objects, attributes/properties, events, processes, and relations, necessary for higher level fusion processing.     

Parallel computational steering for HPC applications using HDF5 files in distributed shared memory

Interfacing a GUI driven visualization/analysis package to an HPC application enables a supercomputer to be used as an interactive instrument. We achieve this by replacing the IO layer in the HDF5 library with a custom driver which transfers data in parallel between simulation and analysis. Our implementation using ParaView as the interface, allows a flexible combination of parallel simulation, concurrent parallel analysis, and GUI client, either on the same or separate machines. Each MPI job may use different core counts or hardware configurations, allowing fine tuning of the amount of resources dedicated to each part of the workload. By making use of a distributed shared memory file, one may read data from the simulation, modify it using ParaView pipelines, write it back, to be reused by the simulation (or vice versa). This allows not only simple parameter changes, but complete remeshing of grids, or operations involving regeneration of field values over the entire domain. To avoid the problem of manually customizing the GUI for each application that is to be steered, we make use of XML templates that describe outputs from the simulation (and inputs back to it) to automatically generate GUI controls for manipulation of the simulation.     

Java-based framework for processing and displaying short-echo-time magnetic resonance spectroscopy signals

Magnetic resonance spectroscopy (MRS) can be used to determine in a non-invasive way the concentrations of certain chemical substances, also called metabolites. The spectra of MRS signals contain peaks that correspond to the metabolites of interest. Short-echo-time signals are characterized by heavily overlapping metabolite peaks and require sophisticated processing methods. To be useful in a clinical environment tools are needed that can process those signals in an accurate and fast way. Therefore, we developed novel processing methods and we designed a freely available and open-source framework (http://www.esat.kuleuven.ac.be/sista/members/biomed) in which the processing methods can be integrated. The framework has a set of abstract classes, called hot spots, and its goal is to provide a general structure and determine the control flow of the program. It provides building blocks or components in order to help developers with integrating their methods in the framework via a plug-in system. The framework is designed with the unified modeling language (UML) and implemented in Java. When a developer implements the framework he gets an application that acts like a simple and user-friendly graphical user interface (GUI) for processing MRS data. This article describes in detail the structure and implementation of the framework and the integration of our processing methods in it.     

MEdit4CEP-CPN: An approach for complex event processing modeling by prioritized colored petri nets

Complex Event Processing (CEP) is an event-based technology that allows us to process and correlate large data streams in order to promptly detect meaningful events or situations and respond to them appropriately. CEP implementations rely on the so-called Event Processing Languages (EPLs), which are used to implement the specific event types and event patterns to be detected for a particular application domain. To spare domain experts this implementation, the MEdit4CEP approach provides them with a graphical modeling editor for CEP domain, event pattern and action definition. From these graphical models, the editor automatically generates a corresponding Esper EPL code. Nevertheless, the generated code is syntactically but not semantically validated. To address this problem, MEdit4CEP is extended in this paper by Prioritized Colored Petri Net (PCPN) formalism, resulting in the MEdit4CEP-CPN approach. This approach provides both a novel PCPN domain-specific modeling language and a graphical editor. By using model transformations, event pattern models can be automatically transformed into PCPN models, and then into the corresponding PCPN code executable by CPN Tools. In addition, by using PCPNs we can compare the expected output with the actual output and can even conduct a quantitative analysis of the scenarios of interest. To illustrate our approach, we have conducted an air quality level detection case study and we show how this novel approach facilitates the modeling, simulation, analysis and semantic validation of complex event-based systems.     

Model-based development of a course of action scheduling tool

This paper shows how a formal method in the form of Coloured Petri Nets (CPNs) and the supporting CPN Tools have been used in the development of the Course of Action Scheduling Tool (COAST). The aim of COAST is to support human planners in the specification and scheduling of tasks in a Course of Action. CPNs have been used to develop a formal model of the task execution framework underlying COAST. The CPN model has been extracted in executable form from CPN Tools and embedded directly into COAST, thereby automatically bridging the gap between the formal specification and its implementation. The scheduling capabilities of COAST are based on state space exploration of the embedded CPN model. Planners interact with COAST using a domain-specific graphical user interface (GUI) that hides the embedded CPN model and analysis algorithms. This means that COAST is based on a rigorous semantical model, but the use of formal methods is transparent to the users. Trials of operational planning using COAST have been conducted within the Australian Defence Force. The work of Lin Zhang was done while he was with the Command and Control Division of the Australian Defence Science and Technology Organisation.