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The efficiency and accuracy of design is critical for construction success. The realization of design is dependent on complete and coordinated design documents that are finalized through the submittal process. This process involves the transfer of design intent from the architect and engineer to the specialty trade contractor for the production of shop drawings. The use of information technology to increase the ability to meet this intent is not being fully utilized today. A case study was selected on the campus of Texas A&M University to investigate the impacts of CAD on the submittal process. The project was selected because it utilized both hand and CAD methods to produce shop drawings. The data collected included all contract documents, submittals, submittal logs, and interviews with the project participants. A comparative analysis was made between the shop drawings that were completed by hand and those that were done by CAD. An analysis quantified the number of notes and corrections made by the reviewers during the submittal process. A separate analysis was made of the number of errors in the interpretation and transferring of background information from the contract documents in the shop drawing production. Finally, interviews were conducted with the project participants to determine the cost associated with utilizing CAD to produce shop drawings. Although based on a single case study, the data showed that CAD had important impacts on the submittal process. The data suggests that when CAD is used to produce shop drawings, there are significantly less notes or corrections by the reviewers. It also suggests that the electronic transfer of design data from the architect and engineer to the subcontractor can ensure better design accuracy and lower overall project cost.

As the continuous trend of Very Large Scale Integration (VLSI) circuits technology scaling and frequency increases, delay optimization techniques for interconnect are increasingly important for achieving timing closure of high performance designs. For the gigahertz microprocessor and multi-million gate ASIC designs it is crucial to have fast algorithms in the design automation tools for many classical problems in the field to shorten time to market of the VLSI chip. This research presents algorithmic techniques and constructive models for two such problems: (1) Fast buffer insertion for delay optimization, (2) Wire sizing for delay optimization and variation minimization on non-tree networks. For the buffer insertion problem, this dissertation proposes several innovative speedup techniques for different problem formulations and the realistic requirement. For the basic buffer insertion problem, an O(n log2 n) optimal algorithm that runs much faster than the previous classical van Ginneken’s O(n2) algorithm is proposed, where n is the number of buffer positions. For modern design libraries that contain hundreds of buffers, this research also proposes an optimal algorithm in O(bn2) time for b buffer types, a significant improvement over the previous O(b2n2) algorithm by Lillis, Cheng and Lin. For nets with small numbers of sinks and large numbers of buffer positions, a simple O(mn) optimal algorithm is proposed, where m is the number of sinks. For the buffer insertion with minimum cost problem, the problem is first proved to be NP-complete. Then several optimal and approximation techniques are proposed to further speed up the buffer insertion algorithm with resource control for big industrial designs. For the wire sizing problem, we propose a systematic method to size the wires of general non-tree RC networks. The new method can be used for delay optimization and variation reduction.

Thesis (M.S.)--University of Florida, 2002. / Title from title page of source document. Includes vita. Includes bibliographical references.

This thesis describes the development of a device called "Oil Separator" which is used for washing vehicles and particularly car washing. The device developed for Mr. Car Bilvård AB in Uppsala, the company's work involves passenger transport and courier services. The company needs an external device that meets the environmental standards to wash their own cars in the premises without the need to modify or reconstruct on the premises ground as the premises is on a leased contract. Work began with a preliminary study on the literatures that describes both the function and structure of designing the device. A few interviews with other car wash companies had been implemented, and some measurements. After collection of the necessary information the specifications of customer requirement was presented . With these requirements a few concepts was generated and weighed using the Pugh matrix for concepts selection for further development. The final concept was further developed and a design has been presented. A design of the washing place was taken up also which does not require any change in the premises by putting it on the ground. A functional smaller prototype of the oil separator was developed and tested.

This thesis is based upon the work done at Westinghouse electric company (WEC)in Västerås during the spring semester of 2015 and describes the development of a quick coupler with associated blade changing tool. These are meant to be used together with a sawing tool that the company uses for the dismantling of nuclear reactors, which is performed under water. The aim of the thesis was to develop a complete manufacturing documentation with drawings and related CAD models which Westinghouse later can use to manufacture the tool and the quick coupler. It was also included in the assignment to, if necessary, modify parts of the saw tool to adapt these to the intended blade changing tool. A number of visits to the company's workshop was made during the time to study the saw that the thesis is based upon. The purpose of these visits was to get a better idea of the dimensions, construction and the field of use of the saw. On three of those occasions various engineers and consultants accompanied us to discuss possible problems with different ideas. This was interspersed with information in the form of literature studies on quick couplers to create a clearer picture of the nature of the task. When enough information had been gathered a functional analysis was made to divide the main problem into sub this phase the idea and concept generating process took place. The methods used for this was mainly brain writing and brainstorming. When enough ideas and concepts had been generated the most promising ideas was selected by using an evaluation matrix, in which the various suggestions were weighted against the parameters that our supervisor thought mattered the most. The next step was to create a computer model of the best concept and finding suitable components in worm gear, electric motor, planetary gears, screws, etc. During the modeling phase further developed of the concept was made until the tool and quick coupler received its final shape whereupon the manufacturing documentation was created.

Transportation projects often involve communication of project information between diverse parties and have been a challenge with increasing complexity. Communication, review and feedback are very important for planners, builders/developers and traffic engineers for successful project execution. Past research was successful in finding effective ways to communicate to stakeholders and improve project performance. 3D/4D CAD modeling has been one among them which offers potential benefits from planning to construction phase owing to its wide range of capabilities. However, there is no single tool to analyze traffic conditions and changing geometry during construction for reviewing and better decision-making. A methodology to use DTA models as a source for traffic information and development of traffic visualization during construction with microsimulation output is discussed in this thesis. The benefits of adding traffic information to 3D/4D CAD models and some potential areas of application are explored. Two case studies on TxDOT transportation construction projects are considered to explain the modeling and analysis for better understanding of different phases of the projects. Also, a small construction scenario was analyzed to validate the traffic data generated from DTA models for their use as an input to microsimulation models. / text

published_or_final_version / abstract / toc / Mechanical Engineering / Master / Master of Philosophy

The degree project is performed at Metso Kamfab. The production is aimed on machines everything from handling of fiber to paper pulp. Metso Fiber and Kamfab are using Pro/Engineer for design and blueprint production. The processing department types the NC-programs in notepad on the basis of the blueprints, the CAD-dates that already is there are not used. The aim with the work is to study if Kamfab can use CAM-system for processing and production of programs for their NC-machines. The objective in this project is to make NC-programs that functions in three special machines. CAD/CAM forms the link between design and production. In a CAD/CAM-system the geometry is created in CAD and can be used directly in CAM for processing. In CAM CL-data is created and after that translated with a postprocessor to NC-code. The postprocessor is used also as a watch over function. Three machines were chosen as experiment items for introducing of CAD/CAM. These are a 7-axis mill, a combined mill/turn and a 3-axis mill. The 7-axis mill and the mill/turn were chosen because they are the most advanced machines. The 3-axis mill was chosen because there was available time in it. Products that were tested were trough, pillar, housing and a part for a toolchanger. When processing the trough ”Surface-Mill” was chosen and a lead-angle was set in the parameters. It was most drilling and a little face milling on both the pillar and the housing. In order to test programs a postprocessor was borrowed that translated CL-data to Heidenhain code. During the test run errors were detected in the programs. This depends on that the postprocessor not where customized for the machine. A postprocessor developed by ourselves was also tested, this one didn’t work because the machine's NC-system couldn’t read ISO standard code. A study visit was done at Structo in Kristinehamn where EdgeCAM is used for NC-processing. It works well and it allows quicker and safer programming. Pro/Engineer is powerful and has a lot of possible adjustments. This makes it complex and takes time to learn. To use Pro/Engineer´s CAM-part it is necessary to have basic knowledge about the CAD-part. Depending on this many companies uses for example EdgeCAM that almost is a pure CAM-system. The processing of the three components functioned well in Pro/Engineer, we could process the components after demands. The problem was to get working programs. An advantage with using CAM is that you can simulate toolpaths. Through this you can see if the tool collides and it also makes it possible to optimize toolpaths. Today, it is a lot of waiting time in the milling machine FPT34 because programs are not completed. This waiting time would be reduced or even eliminated with the aid of CAM. / Examensarbetet är utfört på Metso Kamfab. Deras tillverkning är inriktad på maskiner allt från hantering av flis till framställning av pappersmassa. Metso Fiber och Kamfab använder Pro/Engineer för konstruktion och ritningsframtagning. Vid maskinberedning skrivs sedan NC-program utifrån ritningen, alltså används inte de CAD-data som redan finns. Syftet med arbetet är att undersöka om Kamfab kan använda CAM-system för beredning och framtagning av program till deras NC-maskiner. Målet i detta projekt är att ta fram NC-program som fungerar i tre speciella maskiner. Dessutom skall två CAM-system jämföras, dessa är Pro/Engineer´s CAM-system och EdgeCAM. CAD/CAM bildar kopplingen mellan konstruktion och produktion. I ett CAD/CAM-system kan geometrin som skapats i CAD-delen direkt användas i CAM-delen för beredning. Vid CAM beredning skapas CL-data som översätts med en postprocessor till NC-kod. Postprocessorn används också som en övervakande funktion. Tre maskiner har valts ut som försöksobjekt för införande av CAD/CAM. Det är en 7-axlig NC-fräs, en kombinerad svarv/fräsmaskin och en 3-axlig fräs. Anledningen till att den 7-axliga maskinen och svarv/fräsmaskinen valdes var att de betraktas som de mest avancerade maskinerna. Den enklare 3-axliga maskinen valdes för att det fanns ledig tid i den. Produkter som testades var tråg, pelare, kikhus och en detalj till en verktygsväxlare. Vid beredning av tråget valdes ”Surface-Mill” och i parametrar ställdes en framlutning av verktyget in. Denna metod kallas skränkfräsning. Både för pelare och kikhuset var det främst borrning och lite planfräsning. För att kunna testa program lånades en postprocessor som översatte CL-data till Heidenhain kod. Under testkörningen upptäcktes fel på programmen. Detta berodde på att postprocessorn inte var anpassad till maskinen. En egenutvecklad postprocessor testades också, denna fungerade inte pga. att maskinens styrsystem inte klarade ISO-standard kod. Ett studiebesök gjordes hos Structo i Kristinehamn där EdgeCAM används för NC-beredning. Det fungerar bra att få fram program, det medför snabbare och säkrare programmering. Pro/Engineer är kraftfullt då det finns oerhört många inställningar och justeringar att tillgå. Samtidigt är det ganska komplext och det tar tid att lära sig. För att använda Pro/Engineer´s CAM-del krävs det att man är kunnig i CAD-delen. Beroende på detta så använder många företag exempelvis EdgeCAM som i princip är ett rent CAM-system. Beredningen av de tre komponenterna fungerade bra i Pro/Engineer, man kunde bearbeta komponenterna efter önskemål. Problemet var att få fram fungerande program. En fördel med att använda CAM är att man kan simulera verktygsvägar. Genom detta kan man se om verktyget krockar och det möjliggör också optimering av verktygsvägar. Idag är det en hel del väntetid i fräsverket pga. att program inte finns färdiga. Denna väntetid skulle kunna reduceras eller till och med elimineras med hjälp av CAM.

Rapporten behandlar konstruktion av vinge till en radiostyrd modell av Boeing C-17 Globemaster III. Modellen kommer att tillverkas för försäljning av företaget Mil tech. Spännvidden på vingen är omkring sju meter och med den storleken kommer den troligtvis bli det nuvarande största radiostyrda flygplan som konstrueras för försäljning. Rapporten beskriver konstruktionsförslag för delning av vinge, bak- och framkantsklaff, skevroder, luftbroms, motorpyloner och de valda lösningarna samt vilken vingprofil som modellerandet utgått från. Rapporten behandlar inte själva CAD-modellerandet. / This report considers modelling of a wing to a radio controlled (R/C) model of Boeing C-17 Globemaster III. The airplane will be manufactured for sales. The wingspan is about seven meters and the airplane will probably be the currently largest R/C-plane made for sales. The report describes design proposal for a wing split, trailing and leading edge flaps, ailerons, lift dumpers, engine pylons and the selected solutions and what aerofoil the modelling started from. The report does not consider the CAD-modelling itself.