Meshing complexity: predicting meshing difficulty for single part CAD models

This paper proposes a method for predicting the complexity of meshing computer aided design (CAD) geometries with unstructured, hexahedral, finite elements. Meshing complexity refers to the relative level of effort required to generate a valid finite element mesh on a given CAD geometry. A function is proposed to approximate the meshing complexity for single part CAD models. The function is dependent on a user defined element size as well as on data extracted from the geometry and topology of the CAD part. Several geometry and topology measures are proposed, which both characterize the shape of the CAD part and detect configurations that complicate mesh generation. Based on a test suite of CAD models, the function is demonstrated to be accurate within a certain range of error. The solution proposed here is intended to provide managers and users of meshing software a method of predicting the difficulty in meshing a CAD model. This will enable them to make decisions about model simplification and analysis approaches prior to mesh generation.     

Visual specification of measurements and redesigns for domain specific visual languages

Ensuring model quality is a key success factor in many computer science areas, and becomes crucial in recent software engineering paradigms like the one proposed by model-driven software development. Tool support for measurements and redesigns becomes essential to help developers improve the quality of their models. However, developing such helper tools for the wide variety of (frequently domain specific) visual notations used by software engineers is a hard and repetitive task that does not take advantage from previous developments, thus being frequently forgotten.In this paper we present our approach for the visual specification of measurements and redesigns for Domain Specific Visual Languages (DSVLs). With this purpose, we introduce a novel DSVL called SLAMMER that contains generalisations of some of the more used types of internal product measurements and redesigns. The goal is to facilitate the task of defining measurements and redesigns for any DSVL, as well as the generation of tools from such specification reducing or eliminating the necessity of coding. We rely on the use of visual patterns for the specification of the relevant elements for each measurement and redesign type. In addition, SLAMMER allows the specification of redesigns either procedurally or by means of graph transformation rules. These redesigns can be triggered when the measurements reach a certain threshold.These concepts have been implemented in the meta-modelling tool AToM³. In this way, when a DSVL is designed, it is possible to specify measurements and redesigns that will become available in the final modelling environment generated for the language. As an example, we show a case study in the web modelling domain.     

Semantic interoperability in building design: Methods and tools

Semantic interoperability is a crucial element to make building information models understandable and model data sharable across multiple design disciplines and heterogeneous computer systems. This paper presents a new approach and its software implementation for the development of building design objects with semantics of interoperable information to support semantic interoperability in building designs. The novelty of the approach includes its incorporation of building design domain ontology, object-based CAD information modeling, and interoperability standard to make building information models and model data semantically interoperable. A set of methods are proposed to address the issues of object-based building information representation compliant with the Industrial Foundation Classes (IFC); extension of IFC models with the supplementary information; and semantic annotation of the interoperable and extensible information sets. The prototype implementation of these methods provides a set of Web-enabled software tools for effectively generating, managing, and reusing the semantically interoperable building objects in design applications of architectural CAD, structural analysis, and building code conformance checking.     

基于领域专用语言的应用软件自动生成

在领域专用语言、领域专用库和应用产生器的基础上,提出一种自动生成应用软件的设计框架,详细论述了该设计框架的设计原理和具体的实现过程。该设计框架由三级组成:首先设计一种该应用领域的领域专用语言,它将该应用领域的应用系统作为领域分析的对象,语言上集数据、功能和界面于一体;其次实现该应用领域的一个领域专用库,它提供应用系统级的复用;在这两者的基础上,最后实现一个集工具、语言和库于一体的可视化应用产生器,用它可以快速地开发完整的应用软件。已成功地将该设计框架运用于GIS应用系统领域。用应用产生器开发应用软件,不仅加强了应用系统开发过程的集成,提高了软件的开发效率,实现了软件过程的复用,而且达到了系统级的软件复用。     

An initial industrial evaluation of interactive search-based testing for embedded software

Search-based software testing promises the ability to generate and evaluate large numbers of test cases at minimal cost. From an industrial perspective, this could enable an increase in product quality without a matching increase in the time and effort required to do so.Search-based software testing, however, is a set of quite complex techniques and approaches that do not immediately translate into a process for use with most companies.For example, even if engineers receive the proper education and training in these new approaches, it can be hard to develop a general fitness function that covers all contingencies. Furthermore, in industrial practice, the knowledge and experience of domain specialists are often key for effective testing and thus for the overall quality of the final software system. But it is not clear how such domain expertise can be utilized in a search-based system.This paper presents an interactive search-based software testing (ISBST) system designed to operate in an industrial setting and with the explicit aim of requiring only limited expertise in software testing. It uses SBST to search for test cases for an industrial software module, while also allowing domain specialists to use their experience and intuition to interactively guide the search.In addition to presenting the system, this paper reports on an evaluation of the system in a company developing a framework for embedded software controllers. A sequence of workshops provided regular feedback and validation for the design and improvement of the ISBST system. Once developed, the ISBST system was evaluated by four electrical and system engineers from the company (the ‘domain specialists’ in this context) used the system to develop test cases for a commonly used controller module. As well as evaluating the utility of the ISBST system, the study generated interaction data that were used in subsequent laboratory experimentation to validate the underlying search-based algorithm in the presence of realistic, but repeatable, interactions.The results validate the importance that automated software testing tools in general, and search-based tools, in particular, can leverage input from domain specialists while generating tests. Furthermore, the evaluation highlighted benefits of using such an approach to explore areas that the current testing practices do not cover or cover insufficiently.     

Intelligent software product line configurations: A literature review

A software product line (SPL) is a set of industrial software-intensive systems for configuring similar software products in which personalized feature sets are configured by different business teams. The integration of these feature sets can generate inconsistencies that are typically resolved through manual deliberation. This is a time-consuming process and leads to a potential loss of business resources. Artificial intelligence (AI) techniques can provide the best solution to address this issue autonomously through more efficient configurations, lesser inconsistencies and optimized resources. This paper presents the first literature review of both research and industrial AI applications to SPL configuration issues. Our results reveal only 19 relevant research works which employ traditional AI techniques on small feature sets with no real-life testing or application in industry. We categorize these works in a typology by identifying 8 perspectives of SPL. We also show that only 2 standard industrial SPL tools employ AI in a limited way to resolve inconsistencies. To inject more interest and application in this domain, we motivate and present future research directions. Particularly, using real-world SPL data, we demonstrate how predictive analytics (a state of the art AI technique) can separately model inconsistent and consistent patterns, and then predict inconsistencies in advance to help SPL designers during the configuration of a product.     

A Knowledge-Based Software Engineering Environment for reusable software requirements and architectures

This paper describes a prototype Knowledge-Based Software Engineering Environment used to demonstrate the concepts of reuse of software requirements and software architectures. The prototype environment, which is application-domain independent, is used to support the development of domain models and to generate target system specifications from them. The prototype environment consists of an integrated set of commercial-off-the-shelf software tools and custom developed software tools.The concept of reuse is prevalent at several levels of the domain modeling method and prototype environment. The environment itself is domain-independent thereby supporting the specification of diverse application domain models. The domain modeling method specifies a family of systems rather than a single system; features characterize the variations in functional requirements supported by the family and individual family members are specified by the features they are to support. The knowledge-based approach to target system generation provides the rules for generating target system specifications from the domain model; target system specifications, themselves, may be stored in an object repository for subsequent retrieval and reuse.     

基于域分析的软件体系结构研究

以提高软件RRS特性为目的，提出了建立基于域分析的软件体系结构的观点，在此观点的基础上，对域分析进行了全面的研究，其中包括：定义域分析基本概念，建立完整的域模型，讨论域模型组成之间以及域模型与软件体系结构的相互关系等。最后指出域分析是软件体系结构的基础和前提，并为软件体系结构建立创造良好的工作环境。     

Designing a product family of meshing tools

Applying software engineering concepts can improve the quality of any software development, and this is even more dramatic for complex, large and sophisticated software, such as meshing tools. Software product families are series of related products that make intensive reuse of already developed components. Object-oriented design promotes reusability, so it is specially suited for designing the structure of product families. In this paper we present an object-oriented design of a product family of meshing tools, where all family members share the software structure. By instantiating the structure with particular algorithms and parameters, we can easily produce different tools of the family. A good family design allows us not only to combine existing algorithms but also to easily incorporate new ones, improving software family evolution. We show how the family design is used for the generation of finite element and finite volume meshing tools, as well as a new tool for image processing.     

DRAMA: A framework for domain requirements analysis and modeling architectures in software product lines

One of the benefits of software product line approach is to improve time-to-market. The changes in market needs cause software requirements to be flexible in product lines. Whenever software requirements are changed, software architecture should be evolved to correspond with them. Therefore, domain architecture should be designed based on domain requirements. It is essential that there is traceability between requirements and architecture, and that the structure of architecture is derived from quality requirements. The purpose of this paper is to provide a framework for modeling domain architecture based on domain requirements within product lines. In particular, we focus on the traceable relationship between requirements and architectural structures. Our framework consists of processes, methods, and a supporting tool. It uses four basic concepts, namely, goal based domain requirements analysis, Analytical Hierarchy Process, Matrix technique, and architecture styles. Our approach is illustrated using HIS (Home Integration System) product line. Finally, industrial examples are used to validate DRAMA.     

Feature Nets: behavioural modelling of software product lines

Software product lines (SPLs) are diverse systems that are developed using a dual engineering process: (a) family engineering defines the commonality and variability among all members of the SPL, and (b) application engineering derives specific products based on the common foundation combined with a variable selection of features. The number of derivable products in an SPL can thus be exponential in the number of features. This inherent complexity poses two main challenges when it comes to modelling: firstly, the formalism used for modelling SPLs needs to be modular and scalable. Secondly, it should ensure that all products behave correctly by providing the ability to analyse and verify complex models efficiently. In this paper, we propose to integrate an established modelling formalism (Petri nets) with the domain of software product line engineering. To this end, we extend Petri nets to Feature Nets. While Petri nets provide a framework for formally modelling and verifying single software systems, Feature Nets offer the same sort of benefits for software product lines. We show how SPLs can be modelled in an incremental, modular fashion using Feature Nets, provide a Feature Nets variant that supports modelling dynamic SPLs, and propose an analysis method for SPL modelled as Feature Nets. By facilitating the construction of a single model that includes the various behaviours exhibited by the products in an SPL, we make a significant step towards efficient and practical quality assurance methods for software product lines.     

产品线可变性的需求方法研究

软件产品线领域需求记录了不同软件产品的共性和可变性。在现有需求过程框架下,对产品线需求获取方法与需求分析方法进行了研究,完善了产品线需求可变性的管控机制。以原子需求为视点,提出了利用需求场景获取产品线领域需求的方法;通过原子需求构建的产品需求矩阵与用例需求矩阵,分析得出需求资源的可变性关系;通过可变性关系的形式化描述,建立产品线可变性用例模型。     

A Feature Model Based Framework for Refactoring Software Product Line Architecture

Software product line (SPL) is an approach used to develop a range of software products with a high degree of similarity. In this approach, a feature model is usually used to keep track of similarities and differences. Over time, as modifications are made to the SPL, inconsistencies with the feature model could arise. The first approach to dealing with these inconsistencies is refactoring. Refactoring consists of small steps which, when accumulated, may lead to large-scale changes in the SPL, resulting in features being added to or eliminated from the SPL. In this paper, we propose a framework for refactoring SPLs, which helps keep SPLs consistent with the feature model. After some introductory remarks, we describe a formal model for representing the feature model. We express various refactoring patterns applicable to the feature model and the SPL formally, and then introduce an algorithm for finding them in the SPL. In the end, we use a real-world case study of an SPL to illustrate the applicability of the framework introduced in the paper.     

生成器技术与软件重用

软件工程中一个重要的问题就是如何经济地构造一个大型的软件系统。特定领域软件生成器是解决这个问题的有效工具。领域模型解释了如何从构件库组装系统,而生成器正是对它的实现。该文较为详细地介绍了特定领域软件生成器,并且与其它的软件重用方法进行了比较。文章最后简要介绍了GenVoca生成器,并结合一个数据结构领域的实例以及一个销售／仓库系统进行了进一步的说明。     

Formal Modeling and Verification of Safety-Critical Software

Rigorous quality demonstration is important when developing safety-critical software such as a reactor protection system (RPS) for a nuclear power plant. Although using formal methods such as formal modeling and verification is strongly recommended, domain experts often reject formal methods for four reasons: there are too many candidate techniques, the notations appear complex, the tools often work only in isolation, and output is often too difficult for domain experts to understand. A formal-methods-based process that supports development, verification and validation, and safety analysis can help domain experts overcome these obstacles. Nuclear engineers can also use CASE tools to apply formal methods without having to know details of the underlying formalism. The authors spent more than seven years working with nuclear engineers in developing RPS software and applying formal methods. The engineers and regulatory personnel found the process effective and easy to apply with the integrated tool support.     

基于System Generator的UART通讯

基于System Generator系统级建模工具在Matlab/Simulink环境下完成了UART通讯模块的建模,并生成位流文件下载到Spartan 3E开发板的FPGA芯片中,实现UART通讯数据发送和接收功能。实验结果表明,System Generator系统级建模工具不仅消除了原先系统工程师与软硬件工程师之间的隔阂,而且简化了传统的FPGA开发流程。     

Improving software product line configuration: A quality attribute-driven approach

ContextDuring the definition of software product lines (SPLs) it is necessary to choose the components that appropriately fulfil a product’s intended functionalities, including its quality requirements (i.e., security, performance, scalability). The selection of the appropriate set of assets from many possible combinations is usually done manually, turning this process into a complex, time-consuming, and error-prone task.ObjectiveOur main objective is to determine whether, with the use of modeling tools, we can simplify and automate the definition process of a SPL, improving the selection process of reusable assets.MethodWe developed a model-driven strategy based on the identification of critical points (sensitivity points) inside the SPL architecture. This strategy automatically selects the components that appropriately match the product’s functional and quality requirements. We validated our approach experimenting with different real configuration and derivation scenarios in a mobile healthcare SPL where we have worked during the last three years.ResultsThrough our SPL experiment, we established that our approach improved in nearly 98% the selection of reusable assets when compared with the unassisted analysis selection. However, using our approach there is an increment in the time required for the configuration corresponding to the learning curve of the proposed tools.ConclusionWe can conclude that our domain-specific modeling approach significantly improves the software architect’s decision making when selecting the most suitable combinations of reusable components in the context of a SPL.     

领域分析在C3I仿真测试环境中的应用

领域分析和建模广泛应用于大型软件系统的分析和设计。目前,由于缺乏有效的方法和实验途径,在C^3I系统的建模和设计过程中难以快速建立系统原型,给实际的开发造成了不便。该文将领域技术应用于C^3I仿真测试环境中,从四个紧密相关的不同视点（环境、交互、焦点分析和整体分析）来对系统进行领域分析和建模,介绍和说明了它们的界定范围、表示内容、使用方法以及在领域分析中的作用,并从这四个方面来分析和描述了C^3I仿真测试环境领域模型的分析和设计过程。该仿真测试环境的领域模型已经应用于实践中,指导了某C^3I系统的开发和研制。     

Design parameterization and tool integration for CAD-based mechanism optimization

This paper presents an open and integrated tool environment that enables engineers to effectively search, in a CAD solid model form, for a mechanism design with optimal kinematic and dynamic performance. In order to demonstrate the feasibility of such an environment, design parameterization that supports capturing design intents in product solid models must be available, and advanced modeling, simulation, and optimization technologies implemented in engineering software tools must be incorporated. In this paper, the design parameterization capabilities developed previously have been applied to support design optimization of engineering products, including a High Mobility Multi-purpose Wheeled Vehicle (HMMWV). In the proposed environment, Pro/ENGINEER and SolidWorks are supported for product model representation, DADS (Dynamic Analysis and Design System) is employed for dynamic simulation of mechanical systems including ground vehicles, and DOT (Design Optimization Tool) is included for a batch mode design optimization. In addition to the commercial tools, a number of software modules have been implemented to support the integration; e.g., interface modules for data retrieval, and model update modules for updating CAD and simulation models in accordance with design changes. Note that in this research, the overall finite difference method has been adopted to support design sensitivity analysis.