A graph grammar-based formal validation of object-process diagrams

Two basic requirements from a system’s conceptual model are correctness and comprehensibility. Most modeling methodologies satisfy only one of these apparently contradicting requirements, usually comprehensibility, leaving aside problems of correctness and ambiguousness that are associated with expressiveness. Some formal modeling languages do exist, but in these languages a complete model of a complex system is fairly complicated to understand. Object-process methodology (OPM) is a holistic systems modeling methodology that combines the two major aspects of a system—structure and behavior—in one model, providing mechanisms to manage the complexity of the model using refinement-abstraction operations, which divide a complex system into many interconnected diagrams. Although the basic syntax and semantics of an OPM model are defined, they are incomplete and leave room for incorrect or ambiguous models. This work advances the formal definition of OPM by providing a graph grammar for creating and checking OPM diagrams. The grammar provides a validation methodology of the semantic and syntactic correctness of a single object-process diagram.     

From ethnographic record to system design

This paper explores the issues involved in moving from ethnographic explorations of work in context to a practical contribution to system design. It does so using the example of an interdisciplinary research project involving sociologists and computer scientists in the domain of air traffic control systems. It forms a pair with another paper (Sommerville et al., 1992) exploring these questions from the perspective of our computer science partners. We characterise ethnography as a research method, and consider the differences between undertaking it for strictly sociological or anthropological purposes by contrast with interdisciplinary and design purposes. We summarise some of our results in ethnographic explications of the work of air traffic controllers, and the sociality which it manifests. We describe the dialogues involved in rendering these observations informative for systems design, and the mutual translations implied in attempting to reconcile sociological with software engineering questions about supporting the work. We conclude by specifying some features of cooperative work which an engineering approach is in danger of overlooking; the ways, and limits, in which ethnographers can form a bridge between users and designers; and some of the conflicts of interest entrained in generating technical change.The research is funded by the UK MRC/SERC/ESRC Cognitive Science/HCI Initiative with the title Social Analysis of Control Systems for HCI Design, grant number SPG 8931598. The computer science partners are Professor Ian Sommerville, Dr Tom Rodden, Dr Pete Sawyer and Mr Richard Bentley. Thanks are due to Val King, Kjeldt Schmidt, Ian Sommerville and Tom Rodden for very helpful comments on earlier drafts of this paper.     

From experiment design to closed-loop control

The links between identification and control are examined. The main trends in this research area are summarized, with particular focus on the design of low complexity controllers from a statistical perspective. It is argued that a guiding principle should be to model as well as possible before any model or controller simplifications are made as this ensures the best statistical accuracy. This does not necessarily mean that a full-order model always is necessary as well designed experiments allow for restricted complexity models to be near-optimal. Experiment design can therefore be seen as the key to successful applications. For this reason, particular attention is given to the interaction between experimental constraints and performance specifications.     

From a domain analysis to the specification and detection of code and design smells

Code and design smells are recurring design problems in software systems that must be identified to avoid their possible negative consequences on development and maintenance. Consequently, several smell detection approaches and tools have been proposed in the literature. However, so far, they allow the detection of predefined smells but the detection of new smells or smells adapted to the context of the analysed systems is possible only by implementing new detection algorithms manually. Moreover, previous approaches do not explain the transition from specifications of smells to their detection. Finally, the validation of the existing approaches and tools has been limited on few proprietary systems and on a reduced number of smells. In this paper, we introduce an approach to automate the generation of detection algorithms from specifications written using a domain-specific language. This language is defined from a thorough domain analysis. It allows the specification of smells using high-level domain-related abstractions. It allows the adaptation of the specifications of smells to the context of the analysed systems. We specify 10 smells, generate automatically their detection algorithms using templates, and validate the algorithms in terms of precision and recall on Xerces v2.7.0 and GanttProject v1.10.2, two open-source object-oriented systems. We also compare the detection results with those of a previous approach, iPlasma.     

From regional sensitivity to intra-sensitivity for parametric analysis of free-form shapes: Application to ship design

Robust Parametric Sensitivity Analysis (PSA) is a prerequisite for efficient shape optimisation via parametric modelling. A major challenge PSA has to handle is related to the fact that a parameter can be sensitive in certain local areas of the design space but become insensitive in others. Therefore, setting an applicable space for this analysis becomes a difficult task. In this paper, we introduce the concept of intra-sensitivity to identify parameters whose perturbation has a major impact on the sensitivity index of the remaining parameters. For this purpose, we firstly appeal to Active Subspace Method (ASM) and develop an ASM-based regional sensitivity analysis, which investigates parametric sensitivity in local regions of the design space and aids conducing to parameters’ intra-sensitivity. This regional analysis is applied in conjunction with a Dynamic Propagation Sampling approach, for tackling the computational complexity arising when high-dimensional problems are concerned. Once sensitive and intra-sensitive parameters are identified, then free-form features, correlated to these parameters, are evaluated using a feature saliency map built with the aid of Hausdorff distance. The so resulting methodology has been validated in the area of computer-aided ship design using two parametric modellers: the first one is a Procedural Deformation (PD) modeller which is based on T-splines and involves 24 parameters while the second one is based on Free-Form Deformation (FFD) and involves 104 parameters. The corresponding design spaces have been generated using a parent hull close to the KCS container ship and are analysed against hull’s volume of displacement and total resistance. Finally, the convergence performance of the various components of this approach is compared with state-of-the-art techniques.     

From curve design algorithms to the design of rigid body motions

We discuss the following problem, which arises in computer animation and robot motion planning: given are N positions or keyframes (t_i) of a moving body ³ at time instances t_i. Compute a smooth rigid body motion (t) that interpolates or approximates the given positions (t_i) such that chosen feature points of the moving system run on smooth paths. We present an algorithm that can be considered as a transfer principle from curve design algorithms to motion design. The algorithm relies on known curve design algorithms and on registration techniques from computer vision. We prove that the motion generated in this way is of the same smoothness as the curve design algorithm employed. Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00371-003-0221-3To the memory of Peter Steiner     

From misuse cases to mal-activity diagrams: bridging the gap between functional security analysis and design

Secure software engineering is concerned with developing software systems that will continue delivering its intended functionality despite a multitude of harmful software technologies that can attack these systems from anywhere and at anytime. Misuse cases and mal-activity diagrams are two techniques to model functional security requirements address security concerns early in the development life cycle. This allows system designers to equip their systems with security mechanisms built within system design rather than relying on external defensive mechanisms. In a model-driven engineering process, misuse cases are expected to drive the construction of mal-activity diagrams. However, a systematic approach to transform misuse cases into mal-activity diagrams is missing. Therefore, this process remains dependent on human skill and judgment, which raises the risk of developing mal-activity diagrams that are inconsistent with the security requirements described in misuse cases, leading to the development of an insecure system. This paper presents an authoring structure for misuse cases and a transformation technique to systematically perform this desired model transformation. A study was conducted to evaluate the proposed technique using 46 attack stories outlined in a book by a former well-known hacker (Mitnick and Simon in The art of deception: controlling the human element of security, Wiley, Indianapolis, 2002). The results indicate that applying the proposed technique produces correct mal-activity diagrams from misuse cases.     

From safety analysis to software requirements

Software for safety critical systems must deal with the hazards identified by safety analysis. This paper investigates, how the results of one safety analysis technique, fault trees, are interpreted as software safety requirements to be used in the program design process. We propose that fault tree analysis and program development use the same system model. This model is formalized in a real-time, interval logic, based on a conventional dynamic systems model with state evolving over time. Fault trees are interpreted as temporal formulas, and it is shown how such formulas can be used for deriving safety requirements for software components     

Socio-technical systems: From design methods to systems engineering

It is widely acknowledged that adopting a socio-technical approach to system development leads to systems that are more acceptable to end users and deliver better value to stakeholders. Despite this, such approaches are not widely practised. We analyse the reasons for this, highlighting some of the problems with the better known socio-technical design methods. Based on this analysis we propose a new pragmatic framework for socio-technical systems engineering (STSE) which builds on the (largely independent) research of groups investigating work design, information systems, computer-supported cooperative work, and cognitive systems engineering. STSE bridges the traditional gap between organisational change and system development using two main types of activity: sensitisation and awareness; and constructive engagement. From the framework, we identify an initial set of interdisciplinary research problems that address how to apply socio-technical approaches in a cost-effective way, and how to facilitate the integration of STSE with existing systems and software engineering approaches.     

From early virtual garment simulation to interactive fashion design

Virtual garment design and simulation involves a combination of a large range of techniques, involving mechanical simulation, collision detection, and user interface techniques for creating garments. Here, we perform an extensive review of the evolution of these techniques made in the last decade to bring virtual garments to the reach of computer applications not only aimed at graphics, but also at CAD techniques for the garment industry.As a result of the advances in the developments of virtual garment simulation technologies, we then detail a framework which fits the needs of the garment industry of virtual garment design and prototyping, concentrating on interactive design, simulation and visualization features. The framework integrates innovative tools aimed towards efficiency and quality in the process of garment design and prototyping, taking advantage of state-of-the-art algorithms from the field of mechanical simulation, animation and rendering.     

Predictive-repetitive control with constraints: From design to implementation

This paper addresses the design and implementation of predictive-repetitive control systems, including the case when constraints are imposed. The approach is based on a frequency response decomposition technique that detects the dominant frequency components of the reference signals and embeds them in the predictive-repetitive controller. Analysis and design make use of the frequency response of the closed-loop system and the choice of the structure of the repetitive controller is considered as a balance between the reduction of tracking errors and minimization of the effects on performance of unwanted elements, such as model uncertainty. The implementation of operational constraints on the amplitudes of the control signals, their increments and on the outputs is considered using an on-line solution constructed using quadratic programming and the identification of active constraints. Experimental results from application to a 2 degree-of-freedom robotic system are used to illustrate the design and implementation procedures developed.     

A pilgrim's progress: From cognitive science to cooperative design

This paper provides a glimpse of some different theoretical frameworks and empirical methods in the author's search for theories and practices that might improve the utility and usability of computer artifacts. The essay touches on some problematic aspects of currently accepted theories and techniques in the cognitive sciences, especially in their application to the field of human-computer interaction, and mentions some alternative conceptions based on a cultural-historical approach. The intent is to widen the nature of the debate about appropriate frameworks for discussing human activities especially when we discuss design activities in the context of computer systems development. The paper concludes with some suggestions for more fruitful research directions that involve the active participation of those for whom the research is ostensibly being done, and a greater emphasis on understanding how artifact design and use are inextricably intertwined.This paper originated from a talk entitled From Cognitive Science to Cooperative Design that later appeared in rough paper form in Finnemann, N. O. (Ed.) Proceedings from the Symposium Theories and Technologies of the Information Society (Centre for Cultural Research, Aarhus University, Denmark, Sept. 1989). Some of the ideas and material in the present paper first appeared in Bannon & Bødker (in press) and Bannon (in press).     

Role engineering: From design to evolution of security schemes

This paper presents a methodology to design the RBAC (Role-Based Access Control) scheme during the design phase of an Information System. Two actors, the component developer and the security administrator, will cooperate to define and set up the minimal set of roles in agreement with the application constraints and the organization constraints that guarantee the global security policy of an enterprise. In order to maintain the global coherence of the existing access control scheme, an algorithm is proposed to detect the possible inconsistencies before the integration of a new component in the Information System.     

The role of control in design: From fixing problems to the design of dynamics

This paper is concerned with the role of dynamics and control communities in the design cycle of new products. The paper advocates the need to change the current role from mainly reactively fixing problems to proactively designing beneficial dynamics early in the design cycle. The message is presented with the aid of a case study involving dynamic modeling (barriers), control (current approach), and design of beneficial dynamics (proposed approach) for mitigating combustion instabilities in jet engines. While the discussion is restricted to jet engines, it is hypothesized that the assessment of the current role and merits of the proposed new role apply broadly across multiple industries.     

From single to many-objective PID controller design using particle swarm optimization

International Journal of Control, Automation and Systems - Proportional, integrative and derivative (PID) controllers are among the most used in industrial control applications. Classical PID...     

Logical structure analysis: From HTML to XML

This paper presents an efficient method for extracting a logical structure from a Web document. The proposed method consists of three phases: visual grouping, element identification, and logical grouping. To produce a logical structure more accurately, the proposed method defines a document model that is able to describe logical structure information of a specific document class. Since the proposed method is based on a visual structure from the visual grouping phase as well as a document model that describes logical structure information of a document type, it supports sophisticated structure analysis. Experimental results with HTML documents from the Web show that the method has performed logical structure analysis successfully, compared with previous work. Particularly, the method generates XML documents as the result of structure analysis, so that it enhances the reusability of documents.     

Glottal source processing: From analysis to applications

The great majority of current voice technology applications rely on acoustic features, such as the widely used MFCC or LP parameters, which characterize the vocal tract response. Nonetheless, the major source of excitation, namely the glottal flow, is expected to convey useful complementary information. The glottal flow is the airflow passing through the vocal folds at the glottis. Unfortunately, glottal flow analysis from speech recordings requires specific and complex processing operations, which explains why it has been generally avoided. This paper gives a comprehensive overview of techniques for glottal source processing. Starting from analysis tools for pitch tracking, detection of glottal closure instant, estimation and modeling of glottal flow, this paper discusses how these tools and techniques might be properly integrated in various voice technology applications.     

From turtles to Tangible Programming Bricks: explorations in physical language design

This article provides a historical overview of educational computing research at MIT from the mid-1960s to the present day, focusing on physical interfaces. It discusses some of the results of this research: electronic toys that help children develop advanced modes of thinking through free-form play. In this historical context, the article then describes and discusses the authors own research into tangible programming, culminating in the development of the Tangible Programming Bricks system—a platform for creating microworlds for children to explore computation and scientific thinking.