Feature-based validation reasoning for intent-driven engineering design

Feature based modelling represents the future of CAD systems. However, operations such as modelling and editing can corrupt the validity of a feature-based model representation. Feature interactions are a consequence of feature operations and the existence of a number of features in the same model. Feature interaction affects not only the solid representation of the part, but also the functional intentions embedded within features. A technique is thus required to assess the integrity of a feature-based model from various perspectives, including the functional intentional one, and this technique must take into account the problems brought about by feature interactions and operations. The understanding, reasoning and resolution of invalid feature-based models requires an understanding of the feature interaction phenomena, as well as the characterisation of these functional intentions. A system capable of such assessment is called a feature-based representation validation system. This research studies feature interaction phenomena and feature-based designer's intents as a medium to achieve a feature-based representation validation system. [Continues.

Improving construction design : The lean thinking paradigm

A study has been conducted into improving construction design through the application of the lean thinking paradigm. Its objective was to identify the issues relating to design efficiency and how a lean thinking approach might address these issues. The investigation consisted of examining work already undertaken in the field by other researchers"to identify the state of the art. The change order request system was examined to gain first insights into waste in construction design, and to gauge the size of the opportunity for the application of lean thinking. An Electronic Data Gathering Tool (EDGT) was then developed to allow further exploration of the design decision making process at the system / sub-system level. The EDGT was used on three live construction projects. From the data recorded a design planning tool, Design Decision Planner (DDP), was created to help improve control of the design process and lead to a more standardised approach to construction design. Standardising the approach to product development is an important component of lean thinking. The main recommendations for making construction design lean are: Use DDP to plan and improve control of the design decision making process, assign design responsibility and to make the process more transparent. 2. Measuring progress against planned design is a useful process metric. 3. Improve the designer's cost and programme visibility when choosing between design options. 4. Redefine the role of the quantity surveyor from cost controller to value for money assessor. The role needs to be better integrated into the design process to reach its full potential. 5. Need to develop more rigorous methods of assessing the buildability of design options. This problem could be eased in the short-term by incorporating construction professionals into the early design phases. 6. Designers need to use more process reason drivers when choosing between design options, not just functional criteria. 7. The change order request system could be redesigned to identify the root causes of contract issue design changes and, hence, improve the design decision making process

Marking and making : a characterisation of sketching for typographic design

This research rests on the premise that sketching in paper and pencil is crucial for typographic designers when designing documents. The aim has been to derive a characterisation of the salient aspects of sketching, through an ethnographically-oriented study of designers' use of paper and pencil. The people studied were professional typographic designers, but both the motivations for the research and the characterisation deriving from it relate to other design disciplines, notably industrial and engineering design and architecture. The goal was to identify the underlying functionality supported by sketching, in order to inform the design of future tools for document creation. The characterisation is presented as a framework, with seven main categories: visual characteristics of marks; basic semantic units of design; visual features of sketches; visual and tactile features of sheets of sketches; affordances of sketching; functionality required to support sketching; capacities of the traditional medium. The first four categories deal with the visual qualities of sketches, such as image quality within the line and recurring features in sketches such as different scale, closure, and degree of detail. The functions supported by sketching are suggested to be: interpretability, focus, comparison, simulation of experience, ideas capture and record making. The functionality identified as necessary to support sketching includes the appropriate speed of image generation, image emergence, image manipulation, and image capture and record making. Also necessary are high speed and ease of switching between all the strands mentioned above, and singularity of focus. The supportive capacities of the traditional medium include a rich vocabulary of marks, high image definition, and the continuum-of-activity through the continuity-at-medium, i.e. the natural progression from sketching on paper to making simulations out of paper. In recognition of the respective strengths of the traditional and electronic media, integration between the two is recommended for the design of optimal document creation systems

Investigating Communicability Issues in the Open Data Manipulation Flow

The open data movement advocates that public data should be available in electronic format and accessible via the Internet. As a consequence, large volumes of data have been made available in open data portals. To tackle the complexity and possible social impacts resulting from the overwhelming production, collection, processing of data, the Human-Data Interaction providing mechanisms for citizens to interact with data. In this paper, we explore the flow of open data manipulation, aiming to find problems in the application of the whole flow, in practice, by the citizens. We used the Semiotic Inspection Method to find communication breakdowns in the data collection and data visualization interfaces. The results pointed to some communicability problems such as non-intuitive interfaces, lack of tutorials, excessive difficulties in accessing platforms, inconsistent data, and limited resources. These problems make it difficult for citizens across the flow of open data manipulation

Evaluating complex digital resources

Squires (1999) discussed the gap between HCI (Human Computer Interaction) and the educational computing communities in their very different approaches to evaluating educational software. This paper revisits that issue in the context of evaluating digital resources, focusing on two approaches to evaluation: an HCI and an educational perspective. Squires and Preece's HCI evaluation model is a predictive model ‐ it helps teachers decide whether or not to use educational software ‐ whilst our own concern is in evaluating the use of learning technologies. It is suggested that in part the different approaches of the two communities relate to the different focus that each takes: in HCI the focus is typically on development and hence usability, whilst in education the concern is with the learner and teacher use

Supporting engineering design using knowledge based systems technology with a case study in electricity distribution network design

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis explores the architectural requirements of engineering design support systems based on knowledge based systems technology. The exploration is based on an understanding of the nature of designing as a professional activity and on the extent to which designers' competence can be modelled. Attention is focused on certain salient aspects of designers' competent behaviour. The theoretical study leads to the specification of requirements to be satisfied by a knowledge based system which will support designers in their professional setting and to the proposal of some knowledge based system components which will meet the requirements identified. The theoretical aspect of the thesis is complemented by a case study based on a designer of high voltage electricity distribution networks. The case study illustrates the theoretical component of the thesis and the methodological basis for the work. The practical realizability of the components of the knowledge based systems architecture proposed are demonstrated using the results of the analysis of the knowledge elicited in the case study without prejudicing the general applicability of the ideas. An object-oriented knowledge engineering software development environment is used to demonstrate how some components of the design situation represented can be implemented.Financial support provided by Brunel University

Visual Descriptors: A Design Tool for Visual Impact Analysis

This study is concerned with the development of a practical and effective form of computer-aided analysis of the visual impact of building development in rural areas. Its contribution is fourfold. Firstly, a conceptual model has been developed for the process of seeing in the context of visual impact analysis. Secondly, a mathematical model for a consistent series of visual descriptors has been devised. Thirdly, a suitable design tool has been devised to make use of visual descriptors in visual impact analysis. Fourthly, visual descriptors have actually been implemented as computer software. The concept of visual impact analysis is defined and placed within the wider context of landscape research. The problems faced by a designer in the context of visual impact analysis are identified and the concept of a 'design tool' is introduced and defined. A number of existing computer software packages, intended or used for visual impact analysis, are reviewed critically. The concept of 'visual descriptors' as measures to be used by designers is introduced and examined critically. A conceptual model is presented for the process of seeing in the context of visual impact analysis. A range of possible measures for use as visual descriptors is presented and developed further into a series of precise definitions. A method of implementing visual descriptors is presented together with formal algorithms for the derivation of eight visual descriptors. A software package incorporating these descriptors is presented and verification and case studies of its use carried out. Visual descriptors, as implemented, are assessed for their effectiveness as a design tool for visual impact analysis.Strathclyde University Dept. of Architecture and Building Scienc

A feature-based approach to the Computer-Aided Design of sculptured products

Computer-Aided Design systems offer considerable potential for improving design process efficiency. To reduce the 'ease of use' barrier hindering full realisation of this potential amongst general mechanical engineering industries, many commercial systems are adopting a Feature-Based Design (FBD) metaphor. Typically the user is allowed to define and manipulate the design model using interface elements that introduce and control parametric geometry clusters, with engineering meaning, representing specific product features (such as threaded holes, slots, pockets and bosses). Sculptured products, such as golf club heads, shoe lasts, crockery and sanitary ware, are poorly supported by current FBD systems and previous research, because their complex shapes cannot be accurately defined using the geometrically primitive feature sets implemented. Where sculptured surface regions are allowed for, the system interface, data model and functionality are little different from that already provided in many commercial surface modelling systems, and so offer very little improvement in ease of use, quality or efficiency. This thesis presents research to propose and develop an FBD methodology and system suitable for sculptured products. [Continues.