Darmstadt, Techn. Universiẗat, Diss., 2000.

Techn. Hochsch., Diss., 1998--Aachen.

Refactoring is a technique used by computer scientists for improving program design. The Endy Laboratory has adapted this process to make the genomes of biological organisms more amenable to human understanding and design goals. To assist in this endeavor, we implemented GeneJax, a prototype JavaScript web application for the dissection and visualization stages of the genome refactoring process. This paper reviews key genome refactoring concepts and then discusses the features, development history, user-interface, and underlying implementation issues faced during the making of GeneJax. In addition, we provide recommendations for future GeneJax development. This paper may be of interest to engineers of CAD tools for synthetic biology.

Spatial visualization is the ability of an individual to visualize an object mentally and understand its spatial orientation. It plays an important role in engineering. There have been multiple works that show that spatial visualization skills can be improved with the right training. Creating technical drawings requires mental manipulation and visual thinking. Strong spatial visualization abilities are required for such a mental process. To train students in this process and to improve their spatial skills, Professor Diana Bairaktarova conducted a class in spatial visualization for freshmen in engineering at Virginia Polytechnic Institute and State University. The class consisted of 169 students from different engineering disciplines. One of the major pedagogical techniques used in the class was to give students three assignments on drawing sectional views of mechanical objects with a pre-defined cutting plane. All three assignments had the same six mechanical objects to assess their improvement through the class. Students were not given feedback after completion of each assignment. They were asked to do the first assignment at the beginning of the course, the second assignment during the middle of the semester and the final assignment towards the end of the semester. The students were given instructions on how to draw the 2D sectional views. The assignments were then graded by the teaching assistants for the class and the improvement of the students through the semester was recorded. Assignments were graded manually by two different raters using a pre-defined grading rubric. An inter-rater reliability was established between the graders. There were drawbacks to this process. It was extremely time consuming since there were more than 500 assignments to be graded by the teaching assistants. Also, to establish inter-rater reliability, the assignments had to be graded twice. The process would have been more efficient if there was a software that could automate the grading process. Also, this would eliminate the need to establish an inter-rater reliability. This research aims at developing a software for automatic grading of the technical drawings. The software gives students' feedback on the drawings describing their mistakes. This would give a more complete learning experience as the students would get a better understanding of the internal details of the object with the help of the feedback they are getting. In addition, the software is independent of the CAD platform used to create the drawings. The instructor can also upload a batch of images that can be processed by the software at once. The grading rubric that was used for manual grading can be implemented in the software. The software uses Image processing and Computer Vision toolboxes in MATLAB which enables the comparison between the submitted technical drawing and the source (solution) drawing. The software is currently developed for simple geometries with less complicated features as it is being employed in a course where students are new to CAD environment. Students can also use this software as an interactive learning tool as they create 3D models and sectional views of mechanical objects. The proposed software reduces the amount of effort put in by faculty on grading the assignments. It also gives students feedback on the drawings, making it an interactive tool which improves the learning experience. This software can be a powerful pedagogical tool to improve spatial visualization skills. / Master of Science

This report is the documentation of a master’s thesis which was conducted at Scania CV AB in Södertälje. In this study, the benefits, challenges and conditions of using parametric CAD-models for aiding CFD-simulations and performance-optimization in the product development within internal combustion engines have been assessed. The goal of the thesis included developing and proposing a methodology for design engineers at Scania which will aid them in creating parametric CAD-models which are robust, flexible, comprehensible and intelligent. The study also included assessing the benefits and pre-requisites of such methodology with both practical and theoretical approaches. The ultimate goal of this entire study was to create value for the organization by reducing lead-time in the design process while promoting the production of high quality products. A case-based approach was applied in the study in which modeling strategies resulting from practical investigations and analyzing existing methodologies were implemented on a CAD-model representing the gas-volume of a turbine volute. The chosen strategies were evaluated and subsequently documented as a part of the methodology or discarded depending on its support for the parameterization. The final methodology itself was evaluated based on the quality of the parameterized CAD-model, the time required to create the model and its compatibility to the present design process at Scania CV AB. Finally the methodology was discussed with respect to the different evaluations, and the defined research questions were discussed and answered. The results of the thesis revealed that if parametric CAD-models are made in a structured, standardized and conscious manner, they are able to be highly robust and flexible which gives the models the ability to assume a big set of different forms. The methodology is recommended to be tested in a pilot project and be implemented through internal courses at the company. It was concluded that a methodology which aids the design engineers in creating parametric CAD-models will be the key towards implementing parametric CAD-models in the company and also enabling the many benefits of parameterization, which includes reduced lead-time, enhanced component performance, increased knowledge about the component, and promotion of collaboration among engineers. It was also concluded that parametric models are best suited when the existing design freedom is big and when the time permits performance analyses via optimizations, while challenges include ensuring that the model is parameterized correctly with respect to the CFD-engineers’ wishes while taking into account the requirements from other disciplines. Therefore it is very important to establish a communication between the different engineers. Ultimately, when parametric models are established in the organization, they are recommended to be implemented eventually in both short-term and long-term projects within Scania for its beneficial properties.

Engineering companies are sociotechnical systems in which engineers, designers, analysts, etc. use an array of software tools to follow prescribed product-development processes. The purpose of these amalgamated systems is to develop new products as quickly as possible while maintaining quality and meeting customer and market demands. Researchers at Brigham Young University have shortened engineering design cycle times through the development and use of multiengineer synchronous (MES) CAD tools. Other research teams have shortened design cycle-times by extending seamless interoperability across heterogeneous design tools and domains. Seamless multi-engineer synchronous heterogeneous (MESH) CAD environments is the focus of this dissertation. An architecture that supports both MES collaboration and interoperability is defined, tested for robustness, and proposed as the start of a new standard for interoperability. An N-tiered architecture with four layers is used. These layers are data storage, server communication, business logic, and client. Perhaps the most critical part of the architecture is the new neutral parametric database (NPDB) standard which can generically store associative CAD geometry from heterogeneous CAD systems. A practical application has been developed using the architecture which demonstrates design and modeling interoperability between Siemens NX, PTC's Creo, and Dassault Systemes CATIA CAD applications; Interoperability between Siemens' NX and Dassault Systemes' CATIA are specifically outlined in this dissertation. The 2D point, 2D line, 2D arc, 2D circle, 2D spline, 3D point, extrude, and revolve features have been developed. Complex models have successfully been modeled and exchanged in real time across heterogeneous CAD clients and have validated this approach for MESH CAD collaboration.

A basic requirement of all CAD systems, is that the facilities offered remain relevant to the current needs of users. A characteristic of CAD system users is that their requirements continually change or, to be more accurate, evolve, as their understanding of the design problem and available technology develops. This trait is exemplified by their inability to articulate requirements, both immediate and future with any degree of confidence. Industrial experience of using the traditional methods for developing information systems, which are based upon the Linear Life Cycle (LLC) concept, has proven to be unsuitable for CAD applications. Its failure results from the premise that users' requirements may be accurately stated at the start of the cycle and will not change with time. The need for a new development strategy which supports the evolving requirements of CAD system users is therefore evident. This research resulted in the formulation of such a development strategy. It is based upon an evolutionary approach to system development in which the users' requirements are initially satisfied by the design and implementation of a pilot sub-system which in turn forms the basis for evolution by, its incremental modification and/or extension. The success of this approach principally lies in the ability to modify the software as required with tbe minimum of resources. A major factor determining the degree to which a system may be modified was identified to beits software configuration. A number of design techniques were proposed which contributed to highly flexible configurations, principally through the criteria for functional partitioning, decoupling of functional modules from data storage and the method of organising the data. A new type of data structure was also devised which enabled new data entities and relationships to be added with no modification to the software structure. The development methods resulting from this research were extensively validated during the design and implementation of a large scale industrial CAD system.

Touch står för Tactile Oscillating Universal Caressing Hand och är en idé om att skapa enp rodukt som hjälper människor som lider av eksem, stress eller andra psykiska åkommor. Genom att ge huden taktil massage genom en klappningsrörelse ska Touch ge avslappning till användaren. Det ska finnas flera olika utbytbara munstycken som ger hårdare eller mjukare massage. Rapporten redovisar ett förslag på hur Touch kan utformas för att uppnå dess syfte. Deninnehåller 3D-modeller och ritningar av konstruktionen samt dess individuella delar. Rapporten avhandlar också vilka krav som ställts på Touch och hur arbetet genomförts. Projektet har avgränsats till att endast göra ett förslag på hur Touch kan konstrueras för attuppfylla kraven och detta har gjorts med hjälp av 3D-modeller och ritningar. Det har heller inte tagits någon hänsyn till den elektroniska delen som krävs för att produkten i slutändan ska fungera.

published_or_final_version / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

Trade Training School is the center of excellence for Maintenance Support (MS) training within the NZ Army. This report investigates the feasibility of incorporating CAD into the current training framework for all five of the MS trades within TTS. Due to each trade group being vastly different, CAD software had to be adapted to each individually. This is discussed in some detail within the paper. The physical installation of a CAD suite is also included within the report. TTS is one of the first institutions in NZ to utilise CAD software in the training of tradesmen/ apprentices in NZ.