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1.
This article presents a comparative study of the required number of arithmetic operations necessary for computing robot arm models using the Denavit-Hartenberg symbolic notation and a proposed one. The proposed notation is based on the idea of describing the motion of a robot joint by a pair matrix and the geometry of a link by a shape matrix. This notation needs the use of two coordinate systems for each joint or link. The results prove that the proposed notation reduces the computation time of robot models. For a 6-degrees of freedom robot arm, the computation times of kinematic position, velocity, and dynamic models are reduced respectively by 20%, 5%, and 2%, respectively. The two notations have the same effects on computing the inverse models. © 1993 John Wiley & Sons, Inc.  相似文献   

2.
The Eindhoven approach to quantifier notation is 40 years old. We extend it by adding “distribution comprehensions” systematically to its repertoire; we believe the resulting notation for elementary probability theory is new.After a step-by-step explanation of the proposed notational innovations, with small examples, we give as our exemplary case study the probabilistic reasoning associated with a quantitative noninterference semantics based on Hidden Markov Models of computation. Although that example was the motivation for this work, we believe the proposal here will be more generally applicable: and so we also revisit a number of popular puzzles, to illustrate the notation's wider utility.Finally, we review the connection between comprehension notations and (category-theoretic) monads, and show how the Haskell approach to monad comprehensions applies to the distribution comprehensions we have introduced.  相似文献   

3.
This paper provides evidence that it is possible to migrate structured system designs to UML models. Legacy structured designs can be converted to object-oriented systems without losing data or functionality. The reason for choosing UML is that it is the new standard notation, which tries to build on and integrate object-oriented notations. Extracts from a case study are presented together with the proposed guidelines for the re-engineering process.  相似文献   

4.
一种面向图形化建模语言表示法的元模型   总被引:4,自引:0,他引:4  
何啸  麻志毅  邵维忠 《软件学报》2008,19(8):1867-1880
对于图形化的建模语言,为定义其表示法一般需要解决3个问题:如何定义每个建模元素的图形符号,如何定义图形符号之间的位置关系以及如何将表示法映射到抽象语法.为了方便进行模型转换和代码生成,还需要使用模型化的方式描述建模语言的表示法.通过对UML及其语言家族中的表示法进行总结、分析和归纳,提出了一种表示法定义元模型(notation definition metamodel,简称NDM).针对定义表示法所面临的3个问题,NDM被分成基本图元及其布局、基本位置关系和抽象语法桥三部分.使用NDM定义好的表示法模型还可以通过代码生成技术生成可使用的源代码.将NDM与其他几种定义表示法的方法进行了比较,结果表明,NDM与其他方法相比具有优势.NDM已经在元建模工具PKU MetaModeler中实现.介绍了NDM在实际应用中的几个案例.  相似文献   

5.
Physiotherapy using intelligent robots is emerging as a new approach to recovery for many stroke patients. Although therapy robots have a strong potential in dealing with therapeutic and other medical applications, they have not been fully utilized in everyday therapy activities due to concerns over safety and the lack of friendly robot user/patient interaction models. From the viewpoint of software engineering, a user-centred design based on UML (Unified Modelling Language) has been known to be one of the best solutions to satisfy usability since the design process relies heavily on the analysis of users and their tasks to reach their goals. Therefore, a model-driven approach to interactive system design via UML for therapy robots is needed to make them usable in the real world. This paper proposes such approach and introduces a new graphical notation that describes user interface elements and the methods of connection with hardware/software objects. With the proposed abstract interaction models, prototyping interactive systems can be made faster and allows for their evaluation by users and system developers before implementation in order to improve usability from the perspectives of users and system developers.  相似文献   

6.
ContextDomains where data have a complex structure requiring new approaches for knowledge discovery from data are on the increase. In such domains, the information related to each object under analysis may be composed of a very broad set of interrelated data instead of being represented by a simple attribute table. This further complicates their analysis.ObjectiveIt is becoming more and more necessary to model data before analysis in order to assure that they are properly understood, stored and later processed. On this ground, we have proposed a UML extension that is able to represent any set of structurally complex hierarchically ordered data. Conceptually modelled data are human comprehensible and constitute the starting point for automating other data analysis tasks, such as comparing items or generating reference models.MethodThe proposed notation has been applied to structurally complex data from the stabilometry field. Stabilometry is a medical discipline concerned with human balance. We have organized the model data through an implementation based on XML syntax.ResultsWe have applied data mining techniques to the resulting structured data for knowledge discovery. The sound results of modelling a domain with such complex and wide-ranging data confirm the utility of the approach.ConclusionThe conceptual modelling and the analysis of non-conventional data are important challenges. We have proposed a UML profile that has been tested on data from a medical domain, obtaining very satisfactory results. The notation is useful for understanding domain data and automating knowledge discovery tasks.  相似文献   

7.
ContextMisuse case modeling is a well-known technique in the domain of capturing and specifying functional security requirements. Misuse case modeling provides a mechanism for security analysts to consider and account for security requirements in the early stages of a development process instead of relying on generic defensive mechanisms that are augmented to software systems towards the latter stages of development.ObjectiveMany research contributions in the area of misuse case modeling have been devoted to extending the notation to increase its coverage of additional security related semantics. However, there lacks research that evaluates the perception of misuse case models by its readers. A misread or misinterpreted misuse case model can have dire consequences downstream leading to the development of an insecure system.MethodThis paper presents an assessment of the design of the original misuse case modeling notation based on the Physics of Notations framework. A number of improvements to the notation were suggested. A survey and a controlled experiment were carried out to compare the cognitive effectiveness of the new notation in comparison to the original notation.ResultsThe survey had 55 participants for have mostly indicated that the new notation is more semantically transparent than the original notation. The results of the experiment show that subjects reading diagrams developed using the new notation performed their tasks an average 6 min quicker, while in general the subjects performed their tasks in approximately 14.5 min. The experimental tasks only required subjects reading diagrams and not creating them.ConclusionThe main finding of this paper is that the use of colors and icons has improved the readability of misuse case diagrams. Software engineering notations are usually black and white. It is expected that the readability of other software notations will improve if they utilize colors and icons.  相似文献   

8.
A graphics-based language known as ESML (extended systems modeling language), which is an extension of the data flow diagram notation for representing control logic in models of real-time systems, is analyzed and summarized to provide a rigorous interpretation of ESML symbols and their combinations. Based on elementary and compact (high-level) Petri nets (PNs), to which a succinct introduction is given, formal foundations for ESML, and in particular for its transformation schema (TS) notation, are proposed. Translation principles as well as examples of usual transformation and flow patterns are presented both in TS and PN notation. The resulting PN models are rigorous and accurate models of the dynamics of real-time systems with signals, prompts, and data flows of various kinds. Due to their formally defined token game they can be executed and used to study indeterminism and concurrency of events  相似文献   

9.
For construction of a universal 5-axis virtual machine simulation system, a new methodology is proposed in this paper. The OpenGL library is used to render the virtual environment and to display all motions of the virtual machine tool. In order to achieve the universal construction procedures, the D–H notation is adopted. The user interfaces are developed to help users to select the configuration of machine tool. Once the configuration is decided, the motion directions between adjacent links are known and the kinematic parameters are described by D–H notation. Then the post-processor is derived by D–H notation. Finally, the motion control simulation of the virtual machine tool is executed by D–H transformation matrix. This new methodology can assist developers in constructing the simulation system for the universal 5-axis virtual machine tool efficiently and effectively.  相似文献   

10.
This paper describes the Update Protocol Model (UPM), a formal language for the expression of database update semantics. UPM has been used primarily to capture and communicate in a precise and uniform notation the plethora of database semantics described by a variety of "fourth generation" models, many of which are imprecise when it comes to update semantics. Several computing trends–knowledge-based expert systems, distributed database management systems, and new applications based on higher order semantic models–point to the need for modeling techniques beyond that which current data models such as the relational and entity-relationship models provide.  相似文献   

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