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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
341

Automated shape anthropometry

West, G. January 1993 (has links)
In medicine, ergonomics, the clothing Industry and many other areas such as the design of 'g' suits for military aeroplane pilots and protective clothing for chemical warfare, there is a requirement for the accurate 3-D measurement of the size and shape of the human form. To meet this need a novel whole body scanner has been designed which is capable of measuring both the size and shape of people in a non invasive socially acceptable manner. The scanner uses structured light and an array of television cameras to view free standing subjects while they are being rotated on an electrically driven turntable. The accuracy and repeatability of the scanner is as good as trained anthropometrists using traditional manual methods. A computer program has been written which uses a cubic spline interpolation method to edit and interrogate the data from the scanner and arrange it in a shape matrix form. This is a new way of arranging the data which allows for the 3-D average of several bodies to be obtained and also for the comparison of one body with another. A technique which is essential if 3-D survey work is to be undertaken. Using master files which contain information from a data base of previously scanned people and eight circumferential measurements it is possible to re-create body forms of any size but which correspond to the average shape for that size. The re-creation of body shapes from eight circumferences is accurate enough for the manufacture of all but the most close fitting garments but may be more useful in the future as a replacement for somatotyping (physique classification). It is perfectly possible to manipulate the eight circumferences to create body torsos of almost any shape. Conversely a torso of almost any shape could be defined by eight two digit numbers.
342

Integrated planning systems for the construction industry

Aouad, Ghassan Fouad January 1991 (has links)
This thesis reports on a CAD-based integrated model developed to aid the planning of the construction of in-situ concrete structures. The main aim of this model is to automate the planning process of in-situ concrete structures using data generated by CAD systems. In order to achieve this goal, the integration of a CAD system (AutoCAD 10) and a computerised planning system (Artemis 2000) via a database program (dBase IV) has been achieved on an IBM PS2 Model 70 microcomputer. This enables the generation of network plans in the AutoCAD system which are then automatically transferred to the Artemis system for time and cost analyses. Currently, the system can handle concreting, steel fixing and formwork activities associated with in-situ concrete design elements. However, further enhancement of the model is possible in order to automate the generation of most construction activities. In order to develop this CAD-based integrated planning model, it was necessary to undertake a questionnaire survey on the current status of planning techniques and information technology uses amongst the main UK and US contractors. This survey reveals that many of these contractors are now aware of the benefits that a CAD system can offer to the management and planning of in-situ concrete structures. It was also found that many aspects of information technology such as computer aided design and project management are well within the reach of most of the companies surveyed, and that many recent developments could be used to develop integrated systems as an aid to the planning of construction projects. These findings indicate that the application of such systems could soon become a reality. However, the practicality of these techniques has to be assessed on real life projects which could be the subject of a further research. The CAD-based integrated model described in this thesis offers many facilities for: modeling, drafting, materials and quantities scheduling, time and cost analyses and reporting which were all integrated and incorporated within such a single system. These facilities which have been fully customised within the developed package are easy to be run as the software is user friendly with pull-down and pop-up menus, and help facilities provided at almost all levels. This thesis demonstrates that current software and hardware technologies are more than sufficient to establish new approaches to the planning and management of in-situ concrete structures, particularly in the area of computer aided design. Such approaches can rectify many of the deficiencies found in traditional planning systems. For instance, a CAD-based system could eliminate the re-extraction of information from conventional drawings and documents which could be error prone as an access to the original electronic building model is provided within such a system. In addition, accurate quantities associated with sets of design elements and relevant to the planning process are automatically generated within the system.
343

The use of artificial neural networks for modelling buildability in preliminary structural design

Ballal, Tabarak M. A. January 1999 (has links)
The Construction Industry has long been criticised for the manner in which parties involved in a construction project communicate. Since the early 1960s a number of reports, commissioned by the U.K. governmental agencies, have highlighted a fundamental malaise in the industry: the Jack of integration between design and construction processes. This chronic enigma has manifested itself in cost overruns, prolonged durations, poor quality and complex designs. Buildability and Design for Construction have emerged as key drivers for improving project objectives. Despite considerable progress in identifying the generic concepts ofbuildability, similar progress in its implementation, particularly during the preliminary structural design stage is still in its infancy. This implementation requires a framework for knowledge acquisition of construction information for use by designers. However, there is currently minimal documented experience in capturing technical information, construction expertise and knowledge implicit in previously completed projects for the benefits of new ones. The focus of this research is to develop computerised models for acquiring construction knowledge from past projects to integrate buildability considerations into the preliminary structural design process. A novel artificial intelligence approach has been adopted in this study. Five Artificial Neural Network models have been developed. These allow the generation of an expeditious solution for given sets of design and buildability constraints. Once information is entered into the developed models, a recommendation of which structural scheme to choose is generated instantaneously. Thus, valuable design time is released allowing designers the opportunity to invest this in performing other equally important design tasks. The input information to the models consists of site-related information including site access; availability of working space; and speed of erection, and conceptual design information including type of building; and number of storeys. Four of the five models achieved a high level of accuracy in the range of81.25% to 94.74%. Preliminary structural design is a complex process which relies heavily upon past experience and intuition. These characteristics cannot be represented by the use of conventional computational techniques and only those that are capable of generalising the knowledge implicit in past projects can be of real benefit. In this research, it has been demonstrated that the aforementioned characteristics of structural design fall naturally into the Artificial Neural Networks' problem domain.
344

A manufacturing model to support data-driven applications for design and manufacture

Gutierrez, Arturo M. January 1995 (has links)
This thesis is primarily concerned with conceptual work on the Manufacturing Model. The Manufacturing Model is an information model which describes the manufacturing capability of an enterprise. To achieve general applicability, the model consists of the entities that are relevant and important for any type of manufacturing firm, namely: manufacturing resources (e.g. machines, tools, fixtures, machining cells, operators, etc.), manufacturing processes (e.g. injection moulding, machining processes, etc.) and manufacturing strategies (e.g. how these resources and processes are used and organized). The Manufacturing Model is a four level model based on a de—facto standard (i.e. Factory, Shop, Cell, Station) which represents the functionality of the manufacturing facility of any firm. In the course of the research, the concept of data—driven applications has emerged in response to the need of integrated and flexible computer environments for the support of design and manufacturing activities. These data—driven applications require the use of different information models to capture and represent the company's information and knowledge. One of these information models is the Manufacturing Model. The value of this research work is highlighted by the use of two case studies, one related with the representation of a single machining station, and the other, the representation of a multi-cellular manufacturing facility of a high performance company.
345

A computer-aided design of multi-storey steel frames

Parrott, R. J. January 1980 (has links)
This thesis'describes the application of computer aided optimum design techniques to the design of braced multi-storey steel frameworks. I Optimization methods which have been used successfully in structural engineering are described and classified. Applications of the methods to structural design are reviewed and conclusions are drawn concerning the current state of the structural optimization art, The development of a model which assigns a cost to a typical multi-storey framework is described. A computer programme which comprises this model and-structural design routiness allowing the interactive cost comparison of alternative designs is also described. The thesis goes on to describe the development of suitable problem orientated optimization algorithms which can be combined with the cost model and structural design routines. A design strategy is then developed which, if followed will produce economic designs. The results of using the design system are presented and conclusions are drawn concerning optimum structural design. Finally avenues of possible further research which this research indicates will prove profitable are indicated.
346

Investigation of the processes required for the automation of stitchmarking in shoe manufacture

Tout, Nigel R. January 1989 (has links)
This thesis describes a novel approach to the high speed automatic stitchmarking of shoe upper components by integrating an electrographic printer with a shape recognition system. A critical review of recognition system parameters selects the currently known shape parameters which are most suitable for use in a high speed recognition system with the large number of different shoe components found in a typical shoe factory. These are compared with the parameters actually used in the previously developed recognition system to be used for stitchmarking. A discussion of printing technologies suitable for marking shoe materials with computer generated patterns follows. It is concluded that an electrographic printer has the best combination of characteristics. There follows a description of experiments demonstrating xerography on shoe upper materials, and the design of a system integrating a low-cost laser printer to the recognition system which proved the concept of continuous automatic stitchmarking. With this performing satisfactorily, the system was converted to use a high speed printer requiring the use of an advanced graphics processor for handling the data transformations and interfacing with the printer. Modifications to the printer for operation with shoe materials are described, together with the need for a special toner. A full description of the resulting stitchmarking system is given, followed by details of analyses of its performance. Individual chapters are devoted to the accuracy, recognition efficiency, and the timing of the system. A potential bottleneck in determining the orientation of certain difficult shapes is identified, and faster methods for dealing with these are specially investigated. This concludes that the best approach is to optimise the present method and accelerate the calculations by using a more advanced microprocessor. A discussion of the general running of the machine includes details of problems which occurred with the modified printer mechanism and how these were overcome. Finally, suggestions are made for incorporation in an improved system capable of handling larger shapes with a tenfold speed increase.
347

CAD of microwave dielectric resonator stabilized sources

Seawright, Stephen William James January 1991 (has links)
No description available.
348

Computer automated flattening and draping of garment designs

Seow, Boon Loo January 2000 (has links)
No description available.
349

Object-oriented modelling for improved utilisation of electricity distribution networks

Donaghy, Brian George January 1997 (has links)
No description available.
350

Development of a computer modelling package for predicting engine crankshaft torsional vibrations

McCartan, Charles Declan January 1995 (has links)
No description available.

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