Generating Validation Feedback for Automatic Interpretation of Informal Requirements

This paper describes a method for validating conceptual models of digital systems derived automatically from requirements expressed in natural language. Because natural language is ambiguous and vague, most statements have multiple interpretations. The approach here is to feed back to the requirements authors visualizations of the interpretations of the requirements that have been translated to semantic networks. The visualization task is a component (the Model Generator) of the ASPIN system for automatically interpreting requirements expressed in natural language and diagrams, analyzing the requirements for consistency and completeness, and automatically generating engineering models in the VHDL language. Visualization is performed in two steps: mapping the semantic networks to compound digraphs followed by placement of the nodes of the digraphs to generate a display in terms of icons representing devices, values, actions and events; and connectives indicating carriers, data flow and control dependency.     

基于描述逻辑的概念图推理

分析了概念图在知识表示领域的重要性及其存在的问题,提出了一种基于描述逻辑的具有自动推理功能的扩展概念图.针对概念图的特点和需求,给出了将概念图的一个子集转化为描述逻辑知识库的方法,并证明了该方法的正确性.同时给出了其知识库的一致性、包含关系的自动判断方法,也证明了这些判断方法的正确性.     

Automatic analysis of consistency between requirements and designs

Writing requirements in a formal notation permits automatic assessment of such properties as ambiguity, consistency, and completeness. However, verifying that the properties expressed in requirements are preserved in other software life cycle artifacts remains difficult. The existing techniques either require substantial manual effort and skill or suffer from exponential explosion of the number of states in the generated state spaces. “Light-weight” formal methods is an approach to achieve scalability in fully automatic verification by checking an abstraction of the system for only certain properties. We describe light-weight techniques for automatic analysis of consistency between software requirements (expressed in SCR) and detailed designs in low-degree-polynomial time, achieved at the expense of using imprecise data-flow analysis techniques. A specification language SCR describes the systems as state machines with event-driven transitions. We define detailed designs to be consistent with their SCR requirements if they contain exactly the same transitions. We have developed a language for specifying detailed designs, an analysis technique to create a model of a design through data-flow analysis of the language constructs, and a method to automatically generate and check properties derived from requirements to ensure a design's consistency with them. These ideas are implemented in a tool named CORD, which we used to uncover errors in designs of some existing systems     

Specification Diagrams for Actor Systems

Specification diagrams (SD's) are a novel form of graphical notation for specifying open distributed object systems. The design goal is to define notation for specifying message-passing behavior that is expressive, intuitively understandable, and that has formal semantic underpinnings. The notation generalizes informal notations such as UML's Sequence Diagrams and broadens their applicability to later in the design cycle. Specification diagrams differ from existing actor and process algebra presentations in that they are not executable per se; instead, like logics, they are inherently more biased toward specification. In this paper we rigorously define the language syntax and semantics and give examples that show the expressiveness of the language, how properties of specifications may be asserted diagrammatically, and how it is possible to reason rigorously and modularly about specification diagrams.     

Scenario Analysis in an Automated Tool for Requirements Engineering

 This paper presents an automated tool for scenario-driven requirements engineering where scenario analysis plays the central role. It is shown that a scenario can be described by three views of data flow, entity relationship and state transition models by slight extensions of classic data flow, entity relationship and state transition diagrams. The notions of consistency and completeness of a set of scenarios are formally defined in graph theory terminology and automatically checked by the tool. The tool supports automatic validation of requirements definitions by analysing the consistency between a set of scenarios and requirements models. It also supports automatic synthesis of requirements models from a set of scenarios. Its utility and usefulness are demonstrated by a non-trivial example in the paper. Case studies of the tools are also presented.     

Propositional Logic Constraint Patterns and Their Use in UML-Based Conceptual Modeling and Analysis

An important conceptual modeling activity in the development of database, object-oriented and agent-oriented systems is the capture and expression of domain constraints governing underlying data and object states. UML is increasingly used for capturing conceptual models, as it supports conceptual modeling of arbitrary domains, and has extensible notation allowing capture of invariant constraints both in the class diagram notation and in the separately denoted OCL syntax. However, a need exists for increased formalism in constraint capture that does not sacrifice ease of use for the analyst. In this paper, we codify a set of invariant patterns formalized for capturing a rich category of propositional constraints on class diagrams. We use tools of Boolean logic to set out the distinction between these patterns, applying them in modeling by way of example. We use graph notation to systematically uncover constraints hidden in the diagrams. We present data collected from applications across different domains, supporting the importance of "pattern-finding" for n-variable propositional constraints using general graph theoretic methods. This approach enriches UML-based conceptual modeling for greater completeness, consistency, and correctness by formalizing the syntax and semantics of these constraint patterns, which has not been done in a comprehensive manner before now     

基于知网的汉语普通未登录词语义分析模型

提出一种基于知网的汉语普通未登录词语义分析模型,该模型以概念图为知识表示方法,以2005版知网为语义知识资源,首先参照知网知识词典对普通未登录词进行分词;然后综合利用知网中的知识词典等知识,通过词性序列匹配消歧法、概念图相容性判定消歧法、概念图相容度计算消歧法及语义相似度计算消歧法对中文信息结构进行消歧;最后根据所选择的中文信息结构生成未登录词的概念图,从而实现未登录词的语义分析。该模型在语义分析过程中一方面确定了未登录词中每个已登录词的词义,另一方面构造了该未登录词的语义信息,实验结果证明它可以作为普通未登录词语义分析的原型系统。     

A knowledge-based object modeling advisor for developing quality object models

Object models or class diagrams are widely used for capturing information system requirements in terms of classes with attributes and operations, and relationships among those classes. Although numerous guidelines are available for object modeling as part of requirements modeling, developing quality object models has always been considered a challenging task, especially for novice systems analysts in business environments. This paper presents an approach that can be used to support the development of quality object models. The approach is implemented as a knowledge-based system extension to an open source CASE tool to offer recommendations for improving the quality of object models. The knowledge component of this system incorporates an ontology of quality problems that is based on a conceptual model quality framework commonly found in object models, the findings of related empirical studies, and a set of analysis patterns. The results obtained from an empirical evaluation of the prototype demonstrate the utility of this system, especially with respect to recommendations related to the model completeness aspect of semantic quality.     

基于概念图的中文信息自动转化技术研究

概念图是一种基于语言学、心理学、哲学为一体的一种知识表示方法,目前主要应用于自然语言处理、知识获取、规划及推理等方面。在哈工大IR-Lab资源基础之上,并结合《知网》的世界知识信息,基于概念图理论提出了一种中文文本信息自动转化为概念图的实现方案。可以实现从中文文本直接转化到概念图结构。     

基于模糊含权概念图的主观题自动阅卷方法研究*

由于汉语自身的复杂性、主观题的多样性和灵活性,使主观题的自动阅卷成为计算机无纸化考试的技术难点.结合主观题中简答题的人工批改过程,提出以概念图理论为基础的模糊含权概念图知识表示方法;从汉语自然语言理解的语义分析角度研究了特定课程主观题自动阅卷问题,设计了自动阅卷部分的模块结构,实现了简答题的计算机自动阅卷过程.经过测试分析,该方法反映了考生主观题的答卷情况与人工阅卷的结果基本一致,是一个切实可行的解决方案,而该课题的研究对其他课程主观题的计算机自动阅卷具有一定的参考作用.     

Visual language and graph-based structures in conceptual design

The paper deals with using design knowledge encoded in a visual language and graph-based structures to support the conceptual phase of designing. The visual language is based on the design conceptualization and composed of design diagrams being configurations of geometric primitives. A symbolic representation of design structures in terms of objects specified by the conceptualization and relations between them is defined, and then mapped into diagrams by a given realization. Diagrams are automatically transformed into the corresponding graph-based data structures. The knowledge stored in the graph representations of diagrams is translated into first-order logic formulas which describe generated design configurations. A proposed logic-based reasoning mechanism allows the design supporting system to check the compatibility of designs with the given requirements and constraints. The approach is illustrated by examples of designing configurations of transmission truss towers.     

基于概念图的汉语语义计算的研究与实现

中文信息处理的发展迫切需要加强汉语语义理论的研究,尤其是汉语语义表示形式和语义计算的研究。针对目前汉语语义计算方法的计算结果并不准确的问题,提出了一种基于概念图的汉语语义计算方法。该方法以“知网”为语义知识资源,以概念图为知识表示方法,把自然语言文本转化为概念图,通过概念图的匹配实现语义计算,以改善语义计算的效果。实验结果表明该方法对汉语语义计算是有效的。     

主观题中模糊含权概念图匹配问题研究*

由于汉语自身的复杂性、主观题的多样性和灵活性,使主观题的自动阅卷成为计算机无纸化考试的技术难点。结合主观题中简答题的人工批改过程,提出以概念图理论为基础的模糊含权概念图知识表示方法;从汉语自然语言理解的语义分析角度研究了特定课程主观题自动阅卷问题,设计了自动阅卷部分的模块结构,实现了简答题的计算机自动阅卷过程。经过测试分析,该方法反映了考生主观题的答卷情况与人工阅卷的结果基本一致,是一个切实可行的解决方案,而该课题的研究对其他课程主观题的计算机自动阅卷具有一定的参考作用。     

Modelling knowledge in Electronic Study Books

Abstract  Knowledge graphs are a new form of knowledge representation. They are closely related to semantic networks and can be looked upon as in line with Schank's conceptual dependency theory and Sowa's conceptual graphs. The special feature of knowledge graphs is the use of a very restricted set of types of relations, that is considered to be the basic set of primitive relations. The theory of knowledge graphs is outlined in the first part of the paper. In the second part the possibilities of knowledge graphs for solving problems posed by Electronic (Study) Books will be discussed.     

基于环境建模的物联网系统TAP规则生成方法

用户需求是物联网智能服务的根本驱动力,如IFTTT等很多物联网框架允许用户使用简单的触发-命令编程(TAP)规则进行编程,但它们描述的是设备调度程序,并不是用户服务需求.一些物联网系统提出采用面向目标的需求方法,支持服务目标的分解,但很难保证物联网不同服务间的一致性和服务部署的完整性.为了支持正确的“用户编程”并保证用...     

A compositional semantics of UML-RSDS

This paper provides a semantics for the UML-RSDS (Reactive System Development Support) subset of UML, using the real-time action logic (RAL) formalism. We show how this semantics can be used to resolve some ambiguities and omissions in UML semantics, and to support reasoning about specifications using the B formal method and tools. We use ‘semantic profiles’ to provide precise semantics for different semantic variation points of UML. We also show how RAL can be used to give a semantics to notations for real-time specification in UML. Unlike other approaches to UML semantics, which concentrate on the class diagram notation, our semantic representation has behaviour as a central element, and can be used to define semantics for use cases, state machines and interactions, in addition to class diagrams.     

Task‐based conceptual graphs as a basis for automating software development

It is widely recognized that requirements engineering is a knowledge‐intensive process and cannot be dealt with using only a few general principles. Since knowledge plays a crucial role in software development, software engineers have to describe and organize various aspects of knowledge before the program can be written. A recent work by Robillard reveals that software development can be further improved by recognizing the relevant knowledge structures. In this paper, we propose the use of a task‐based conceptual graphs (TBCB) framework as a basis for automating software development. By structuring and operationalizing conceptual graphs, TBCG specifications can be transformed into executable programs automatically. To construct a conceptual model, task‐based specification methodology is used as the mechanism to structure the knowledge captured in conceptual models, whereas conceptual graphs are adopted as the formalism to express task‐based specifications and to provide a reasoning capability for the purpose of automation. Once task‐based graphs have been constructed and verified, a blackboard system will automatically transform TBCG specifications into a software system composed of database schemas, knowledge base, and user interfaces. A meeting scheduling system is used as an illustrative example to demonstrate our approach. © 2000 John Wiley & Sons, Inc.