Experienced Designers Research Articles

Evolutionary optimisation in chute design

Chute design is a complex process that takes into account many competing objectives and relies heavily on the intuition of an experienced designer. In this paper, we examine one small part of chute design, which is the choice of curve or profile that the chute follows. Overall, this choice relies on minimising wear in the chute/product and impact on the belt. The optimisation problem is a complex one with nonlinearities in both the governing equation and the objective function. In this paper, we solve the optimisation problem by writing it as an evolutionary system, which is subject to Darwinian natural selection. The evolutionary method is detailed, and optimal loading chute profiles are generated using an evolutionary strategy.

Constructive perception: Coordinating perception and conception toward acts of problem‐finding in a creative experience1

Abstract: Fostering better performance in a creative experience is an issue in every institution of design or art. What aspect does a creative experience possess and what kind of cognitive processes constitute it? How should students be trained to entertain the use of cognitive skills, if any, in building up a creative experience of their own? The purpose of the present paper is to examine these issues to lay the foundation for the pedagogy of a creative experience. Examining the cognitive processes of an experienced architect, we found that a creative experience has the aspect of problem‐finding; an act of formulating one's own problems and resolving them rather than just solving a presented problem. Further, we found that a coordination of both perceptual reorganization and conceptual generation constitutes an act of problem‐finding in a creative experience. Experiments using ambiguous drawings have shown that coordinating one's own perception and conception for inventing novel interpretations requires a cognitive skill, what we call the skill of constructive perception; that is, to be self‐aware of the way perception underlies the current interpretation and thereby reorganize perception and generate novel interpretations. How to help students master this skill and how to design educational programs to allow for accomplishment of acts of problem‐finding will be discussed.

Using generative design patterns to generate parallel code for a distributed memory environment

A design pattern is a mechanism for encapsulating the knowledge of experienced designers into a re-usable artifact. Parallel design patterns reflect commonly occurring parallel communication and synchronization structures. Our tools, CO2P3S (Correct Object-Oriented Pattern-based Parallel Programming System) and MetaCO2P3S, use generative design patterns . A programmer selects the parallel design patterns that are appropriate for an application, and then adapts the patterns for that specific application by selecting from a small set of code-configuration options. CO2P3S then generates a custom framework for the application that includes all of the structural code necessary for the application to run in parallel. The programmer is only required to write simple code that launches the application and to fill in some application-specific sequential hook routines. We use generative design patterns to take an application specification (parallel design patterns + sequential user code) and use it to generate parallel application code that achieves good performance in shared memory and distributed memory environments. Although our implementations are for Java, the approach we describe is tool and language independent. This paper describes generalizing CO2P3S to generate distributed-memory parallel solutions.

Solid model reconstruction from engineering paper drawings using Genetic Algorithms

The wide applications of CAD/CAM technologies have promoted the development and application of many advanced technologies, such as digital manufacturing, rapid prototyping, enterprise resources planning, computer integrated manufacturing, concurrent engineering, virtual reality, and mass customization. These advanced technologies all need to be supported by three-dimensional (3D) solid models of products. Most enterprises, however, still organize their production using 2D paper drawings, which makes difficulties for the application of these advanced technologies. It is needed to convert engineering paper drawings into 3D solid models for applications. Based on holo-extraction of information from paper drawings, this paper develops a systematic 3D reconstruction method, which simulates an experienced human designer's thinking mode in transforming inaccurate outlines with inaccurate projection relationships in 2D drawings into 3D image, with the aid of Genetic Algorithms.

Avoiding design errors: a case study of redesigning an architectural studi o

Most design problems have multiple interacting constraints and levels of analysis. Some designers are able to reduce errors by developing heuristics and rules of thumb that lighten the cognitive load that such design problems impose. In this study we explore these heuristics by studying three groups of experienced architects solving a one-hour design problem that involves issues of multiple levels of spatial organization. Only one group was able to solve the problem. A special coding scheme was developed to explore the use of several kinds of heuristics such as problem decomposition into design units, rules of thumb from domain knowledge and strategic design moves. The differences in heuristics were examined to identify possible causes for these errors.

Information architecture for the World Wide Web

From the Publisher: Some Web sites work and some don't. Good Web site consultants know that you can't just jump in and start writing HTML, the same way you can't build a house by just pouring a foundation and putting up some walls. You need to know who will be using the site, and what they'll be using it for. You need some idea of what you'd like to draw their attention to during their visit. Overall, you need a strong, cohesive vision for the site that makes it both distinctive and usable. Information Architecture for the World Wide Web about applying the principles of architecture and library science to Web site design. Each Web site like a public building, available for tourists and regulars alike to breeze through at their leisure. The job of the architect to set up the framework for the site to make it comfortable and inviting for people to visit, relax in, and perhaps even return to someday. Most books on Web development concentrate either on the aesthetics or the mechanics of the site. This book about the framework that holds the two together. With this book, you learn how to design Web sites and intranets that support growth, management, and ease of use. Special attention given to: The process behind architecting a large, complex site Web site hierarchy design and organization Techniques for making your site easier to search Information Architecture for the World Wide Web for Webmasters, designers, and anyone else involved in building a Web site. It's for novice Web designers who, from the start, want to avoid the traps that result in poorly designed sites. It's for experienced Web designers who have already created sites but realize that something is missing from their sites and want to improve them. It's for programmers and administrators who are comfortable with HTML, CGI, and Java but want to understand how to organize their Web pages into a cohesive site. The authors are two of the principals of Argus Associates, a Web consulting firm. At Argus, they have created information architectures for Web sites and intranets of some of the largest companies in the United States, including Chrysler Corporation, Barron's, and Dow Chemical.

The Manufacturing Advisory Service: Web-based process and material selection

The Manufacturing Advisory Service (MAS) is a concept level manufacturing process and material selection tool, geared toward educating designers in basic process capabilities and informing experienced designers about new technologies. The designer enters a dialogue with the MAS, answering questions about production quantity, typical tolerances, physical size, overall shape and cost requirements. At each step along the way, the user is presented with an updated, ranked list of manufacturing options. The list updates as soon as values are entered, and the underlying criteria that contribute to the rank are not obscured. This list can then be combined with material selection, resulting in an optimized matching of process/material pairs to the total set of requirements. The MAS is interlinked with web pages of instructions, tutorials, and references explaining the program, fabrication processes and material choices. The MAS performs its calculations using capability data from a remote database. The current version of the Manufacturing Advisory Service is located at: Http://cybercut.berkeley.edu/mas2/

Database-supported documentation and verification of pressure relief device design in chemical plants

Abstract In this paper the results of a multi-year analysis of the pressure relief devices located in several plants in major chemical sites are summarized. The analysis consisted of a systematic evaluation of existing safety valves and rupture discs including the identification of the service conditions and design cases as well as the sizing calculations of the individual device and associated piping. Furthermore, from the total amount and the hazardous potential of the effluents the necessity of retention systems is evaluated to ensure a safe disposal. Because the knowledge in the field of emergency pressure relief changed very rapidly in recent years, the design of some safety devices was not according to the state of the art. An essential part of the verification program was the recommendation of measures to find the most economical yet technically correct way to correct these deficiencies. Rather than by carrying out wholesale replacement of an incorrectly sized safety device or vent line, often a reduction of the mass flow rate to be discharged, for example, by an orifice in a supply line, is sufficient. Results of the analysis were recorded on a novel database to capture the sizing information and maintain correct pressure relief device sizing into the future. The systematic databased approach has been used for the evaluation of about 4000 safety devices so far. The procedure has been proven to enable an experienced design engineer to carry out the analysis of a great number of pressure relief devices in a time-saving, reliable and reviewable way.

Architectural design of a secure forensic state psychiatric hospital.

This article describes the architectural design of a secure forensic state psychiatric hospital. The project combined input from staff at all levels of the client organization, outside consultants, and a team of experienced architects. The design team was able to create a design that maximized patient dignity and privacy on one hand, and the ability of staff to observe all patient activity on the other. The design centers around 24-bed units, broken into smaller living wings of eight beds each. Each eight-bed living wing has its own private bathrooms (two) and showers (two), as well as a small living area solely reserved for these eight patients and their guests. An indoor-outdoor dayroom allows patients to go outside whenever they choose, while allowing staff to continue observing them. The heart of the facility is a large treatment mall, designed to foster the acquisition of social, emotional, cognitive, and behavioral skills that will help patients to safely return to their communities.

Verwaltung und Wiederverwendung von Modellen im industriellen Entwicklungsprozess

Die Verwendung modellbasierter Methoden zur Unterstützung von Planung, Entwurf und Betrieb verfahrenstechnischer Prozesse und Anlagen hat in den letzten Jahren stärker Einzug in die tägliche Praxis des Ingenieurs gehalten. Jedoch zeigt sich zunehmend, dass schon die Modellerstellung mit Standardwerkzeugen zur Fließbildsimulation einen erfahrenen Ingenieur verlangt, so dass die entstandenen Modelle nicht nur einen Wert im Sinne der zur Erstellung benötigten Ressourcen darstellen, sondern vor allem einen Großteil des Wissens eines Unternehmens über Produkte und deren Produktionsprozesse manifestieren. Es ist daher sinnvoll, die Kosten der Modellerstellung durch Wiederverwendung von Modellen und Erfahrungen zu senken. Der vorliegende Bericht versucht, einen Überblick über die Thematik der Modellverwaltung und -verwendung zu geben. Aus einigen motivierenden Szenarien werden Anforderungen an ein System zur Modellverwaltung abgeleitet, an denen existierende Methoden und Werkzeuge gespiegelt werden. Daraus wird die Konzeption eines Modellverwaltungssystems abgeleitet. Nach der Vorstellung einer prototypischen Realisierung dieser Konzeption schließt der Artikel mit einem Ausblick. The Management and Reuse of Models in Industrial Design Processes The use of model-based methods for the support of the planning, designing, and operating of chemical processes and plants has recently gained increasing importance in the daily work of the process engineer. However, it is becoming more obvious that already the design of mathematical models by the use of standard flowsheet simulation tools requires an experienced designer. Therefore, the developed models not only represent a value considering the resources required for their development, but especially they contain a large amount of knowledge of an enterprise about its products and production processes. It is hence reasonable to lower the costs of model development by reuse of models and experiences. This report gives an overview about the systematic long-term management and use of mathematical models. Some motivating scenarios help to derive requirements for a model management system and to evaluate existing methods and tools. From these results, the concept of a model management system is derived. After presenting a prototypical implementation, this article concludes with an outlook.

Intelligent approaches for generating assembly drawings from 3-D computer models of mechanical products

In order to reduce the time of mechanical product design and ensure the high quality of their assembly drawings, this paper develops an intelligent approach for generating assembly drawings automatically from three-dimensional (3-D) computer assembly models of mechanical products by simulating the experienced human designer's thinking mode with the aid of computer graphics and knowledge-based expert system. The key issues include the strategies and methods for selecting the necessary views in an assembly drawing, determining necessary sectional views in each view, eliminating the unreasonable projective overlap of the components in each view, and minimizing the numbers of both the views in an assembly drawing and the sectional views in each view. Based on the approach, corresponding software prototype was developed. Finally, it is demonstrated, from an example of the fixture in a modularized drilling machine, that its assembly drawing was generated successfully using this intelligent software prototype.

Automated simplified analysis of analogue circuit behaviour based on fully symbolic relations between parameters

Symbolic circuit analysis provides the key for understanding the mechanisms underneath circuit operation, and it can be used to obtain predictive models of circuit behaviour. Symbolic analysis has many applications in the design of analogue circuits but is severely limited by the size of the resulting expressions. Thus an efficient approximation strategy is required for successful symbolic analysis of large analogue circuits. A fully symbolic procedure for the simplification of large expressions, which mimics the heuristic procedures followed by an experienced designer (based on the relations between the parameters of the circuit), is presented in this paper. This simplification strategy is particularly well suited to be combined with some circuit level partition algorithms, leading to a blend between simplification after generation (SAG) and simplification during generation (SDG). The algorithms have been implemented and integrated on a prototype software package for the automated analysis and design of analogue circuits.

Softening Up the Facts: Engineers in Design Meetings

Engineers are commonly stereotyped as being machine-like in their obsession with technical facts and traditional representations of the engineering design process have only tended to support this view. In a series of conversational vignettes, taken from three design meetings held at a small engineering organization in the United Kingdom, this paper shows that the traditional stereotype is badly mistaken. The group of design engineers studied reveal a subtle mastery of rhetoric, and great skill in drawing out the consequences of ‘factual’ – that is to say commonly agreed - information. The vignettes show just how far the process of engineering design is a process dependent on sketching out possible futures in words, then exercising aesthetic judgement in choosing one particular course of action. The paper concludes by suggesting that if these skills are indeed a large part of being an experienced engineering designer, then perhaps they should be explicitly taught at undergraduate level. This would certainly be a significant step in liberalising traditionally conservative engineering design education. Presents information on a study which examined some of the findings about the use of language in the engineering design process using a discourse analytic method. Study of language in the design process; Segments of engineering design conversation; Discussion and conclusions.

Theoretical computation of the electrical conductivity of thermal plasmas-application to plasma torch design of an electrothermal launcher

Designing a plasma torch that allows the ignition of gun propellant is generally complex. In this paper, however, we show that it is possible to design a torch from using simplified calculation of electrical conductivity with the help of an experienced design method (Doehlert matrix). First, we explain how to obtain plasma composition both at and out of thermal equilibrium. Then, we compare the simplified calculation with the complete calculation of electrical conductivity. Then, we construct a Doehlert matrix as a function of temperature and thermal nonequilibrium. Finally, we study the length/diameter ratio versus the length and resistivity.

Automatic analogue circuit synthesis using genetic algorithms

Most analogue systems are designed manually because automatic circuit synthesis tools are available for only a limited range of design problems. A new approach to circuit synthesis based on genetic algorithms is presented. Using this method it is possible in principle to synthesise circuits to meet any linear or nonlinear, frequency-domain or time-domain, specification. When applied to existing filter design problems this circuit synthesis method produces design solutions that are more efficient than those resulting from formal design methods or created manually by an experienced analogue circuit designer.

Observed finite element capabilities and limitations from multi-team simulations of three concrete shell structures

This paper describes a study whose primary intention was to determine how well state-of-the-art analytical/numerical methods could predict the response of three shell structures in the service-level and strength-level regimes. Presented herein are the results of six finite element analyses, performed by different analysts of three, reinforced concrete shells. The shells were scale models of: an end-supported cylinder with edge beams; an end-supported, three-unit folded plate without edge beams; and a hyperboloid of revolution. The results of the analyses generally showed good agreement between predicted and measured displacements before cracking. Significant differences were noted between the different numerical results, and between numerical and experimental results from post-cracking to structural collapse. Nevertheless, it is concluded that the finite element approaches presented here can provide a suitable platform for the analysis and design of these shells if used by an experienced designer.

Automated conceptual design of mechanisms

Traditionally, the conceptual design of mechanisms was an art, based primarily on the experience of the designer. Today, despite the great advances in the science of machine systems, mechanism design is still a mixture of art and science. The basic premise behind this research was that experienced designers create complex mechanisms, in part, by concocting abstract representations of simpler building blocks. We made attempts to identify a finite set of design building blocks and to represent them in a manner that enables a rational, and therefore a computable, scheme for creation of mechanisms. Based on a systematic investigation of hundreds of existing mechanisms and machines, we first identified a finite set of kinematic building blocks. We then devised a matrix representation scheme that not only captures the essential nature of the building blocks, but also enables automatic decomposition of a given task into simpler sub-tasks. The matrix representation scheme served as a formal means to: (a) represent and reason with the building blocks at different levels of abstraction, (b) generate alternate conceptual designs, and (c) facilitate rapid simulation of design concepts by readily connecting a series of building blocks. The synthesis methodology based on the matrix representation was successfully implemented in a computer program for design of function generating mechanisms. The program takes as input the user supplied specification of input/output motion requirements and constraints, and automatically generates alternate conceptual designs. The matrix representation method and the automated design procedure are described in this paper, along with a design example.

Description of hull form and evaluation of ship performance (3rd Report)

Experienced ship designers have been done the optimization of hull form and/or improvements of propulsive performance in the performance design procedure using their metaphysical information and analogized knowledge-process abilities based on their long-continued experiences. It may have been because that there have not been any formulations which make it possible to describe and evaluate the frame line configuration explicitly and quantitatively.In the second paper, the authors introduced a method for expressing and describing the frame line configuration using the Fourier Descriptors (FD), and showed that it is possible to describe almost all frame lines of ship's aft body and their small and fine changes. They also showed that FD is an appropriate method to express the relation between frame line configuration and self-propulsion factors.In the present paper, they discuss the effects of fine changes of frame line on the changes and improvements of self-propulsion factors (1-w) using the Fourier Descriptors. They show that the process of determining frame line configuration and its fine changes for improvements of self-propulsion factors that have been done intuitively and metaphysically by experienced ship designers are quite reasonable.

Coupling of magnetic design choices to DC-to-DC converter electrical performance

The design of an energy-storage reactor in a large measure determines the performance of most high-efficiency switched-mode DC-to-DC power converters. No other component has such a dramatic effect on the circuit waveforms and the distribution of circuit losses. It is often difficult, even for experienced designers, to visualize the complex relationships between the choices of magnetic design parameters and the resulting electrical performance of the power stage. This paper develops a methodology that allows the designer to relate the magnetic design choices of core material, core geometry, number of turns and relative permeability to the electrical performance of the power stage.

Relation between hull form and propulsive performance

Generation of Lines, the underwater hull form of ships is an essential process in the initial designof ships.Technology innovation in the field of ship engineering has not changed the generation of lines. It may be because that the generation of lines requires an analogized information - process ability that can discriminate the fine distinction of underwater hull form. This kind of ability is quite metaphysical and has been piled up only in the memory of experienced designers. And, one of the most important is that propulsive performance of ships has been improved by ship designers' efforts based on their individual experiences.In order to take over the sophisticated ability of experienced designers, it is necessary to extract metaphysical relations between hull form and ship performance.In the 1st report, the authors showed that it is possible to obtain information about hull form by means of Fourier Descriptors (FD's). They applied the FD's for expressing/discriminating fine difference of underwater hull form and its effect on hydrodynamic characteristics of 2-dimensional oscillating bodies.In the present paper, they apply the FD's for expressing and understanding the relations between hull form and propulsive performance of ships. Using published results of self propulsion experiments in a towing tank, they show relations between self-propulsion factors and hull form for 123 model ships by means of FD's. As the results, they show that hull form configuration and self-propulsion factor (1-w) have close relations that have not been explained positively. It may mean that experienced/skilled ship designers have taken over the metaphysical ability for discriminating/evaluating fine changes of underwater hull form.