ABSTRACT Beach and nearshore surveys are conducted in a variety of ways, the most commonly used being the level-and-transit method; because it is inexpensive, time conducive and highly accurate. Specifically, beach surveys are conducted to better understand cross-shore, long-shore sediment transport processes, as well as to quantify volume changes, which are used to evaluate beach performance. In this study, a section of the beach on Sand Key, FL was surveyed using rod-and-transit. In addition to the commonly used linear data analysis, a non-linear analysis was conducted using NURBS (Non-Uniform Rational B-Splines). Survey data was collected within a short time window to ensure minimal environmental changes associated with waves and anthropological factors. Beach profiles were surveyed using two spatial resolutions, including 1) a typical variable resolution determined by the rodman based on observed morphology changes, and 2) a uniform, high resolution of 25 centimeters per point. The results indicate that variable resolution survey with careful observation by the rodman provided adequate accuracy as compared to the very high-resolution survey. The goal of this study is to create a realistic surface between the beach profiles that are spaced relatively far apart. The commonly used contouring method (a linear method) may create mismatch among major morphology units, .e.g., bar crest, if they have different elevations alongshore. Here a non-linear method is developed by 1) identifying major morphological units, in this case dune top, berm crest, trough bottom, and bar crest 2) linking the units using a cubic spline, and 3) generating a surface using a NURBS sweep2 function. Bisector profiles are sliced from the surface generated using linear and non-linear methods, and compared with surveyed profiles at the same location. The profiles generated using the non-linear method matched more closely to the measured profile than that from the linear method. The non-linear NURBS surface resulted in a consistently greater beach volume between the surveyed profiles than the linear method of volume calculation.

This thesis derives a first approximation model that will describe the flow of fluid in microfluidic devices such as in microchannels, microdiffusers and micronozzles using electrical network modelling. The important parameter that is of concern is the flow rates of these devices. The purpose of this work is to contribute to the physical component of our interactive Virtual Reality (VR)-prototyping tool for MEMS, with emphasis on fast calculations for interactive CAD design. Current calculations are too time consuming and not suitable for interactive CAD with dynamic animations. This work contributes to and fills the need for the development of MEMS dynamic visualisation, showing the movement of fluid within microdevices in time scale. Microfluidic MEMS devices are used in a wide range of applications, such as in chemical analysis, gene expression analysis, electronic cooling system and inkjet printers. Their success lies in their microdimensions, enabling the creation of systems that are considerably minute yet can contain many complex subsystems. With this reduction in size, the advantages of requiring less material for analysis, less power consumption, less wastage and an increase in portability becomes their selling point. Market size is in excess of US$50 billion in 2004, according to a study made by Nexus. New applications are constantly being developed leading to creation of new devices, such as the DNA and the protein chip. Applications are found in pharmaceuticals, diagnostic, biotechnology and the food industry. An example is the outcome of the mapping and sequencing of the human genome DNA in the late 1990's leading to greater understanding of our genetic makeup. Armed with this knowledge, doctors will be able to treat diseases that were deemed untreatable before, such as diabetes or cancer. Among the tools with which that can be achieved include the DNA chip which is used to analyse an individual's genetic makeup and the Gene chip used in the study of cancer. With this burgeoning influx of new devices and an increase in demand for them there is a need for better and more efficient designs. The MEMS design process is time consuming and costly. Many calculations rely on Finite Element Analysis, which has slow and time consuming algorithms, that make interactive CAD unworkable. This is because the iterative algorithms for calculating the animated images showing the ongoing proccess as they occur, are too slow. Faster computers do not solve the void of efficient algorithms, because with faster computer also comes the demand for a fasters response. A 40 - 90 minute FEA calculation will not be replaced by a faster computer in the next decades to an almost instant response. Efficient design tools are required to shorten this process. These interactive CAD tools need to be able to give quick yet accurate results. Current CAD tools involve time consuming numerical analysis technique which requires hours of numerous iterations for the device structure design followed by more calculations to achieve the required output specification. Although there is a need for a detailed analysis, especially in solving for a particular aspect of the design, having a tool to quickly get a first approximation will greatly shorten the guesswork involved in determining the overall requirement. The underlying theory for the fluid flow model is based on traditional continuum theory and the Navier-Stokes equation is used in the derivation of a layered flow model in which the flow region is segmented into layered sections, each having different flow rates. The flow characteristics of each sections are modeled as electrical components in an electrical circuit. Matlab 6.5 (MatlabTM) is used for the modelling aspect and Simulink is used for the simulation.

This dissertation aims to advance the field of structural optimization by creating and demonstrating new methodologies for the explicit inclusion of manufacturing issues. The case of composite aerospace structures was a main focus of this work as that field provides some of the greatest complexities in manufacturing yet also provides the greatest incentives to optimize structural performance. Firstly, the possibilities for modifying existing FEA based structural optimization methods to better capture manufacturing constraints are investigated. Examples of brick-based topology optimization, shell-based topology optimization, parametric sizing optimization and manufacturing process optimization are given. From these examples, a number of fundamental limitations to these methods were observed and are discussed. The key limitation that was uncovered related to a dichotomy between analytical methods (such as FEA) and CAD-type methods. Based on these observations, a new Knowledge-Based framework for structural optimization was suggested whereby manufacturing issues are integrally linked to the more conventional structural issues. A prototype system to implement this new framework was developed and is discussed. Finally, the validity of the framework was demonstrated by application to a generic composite rib design problem.

Transfer of information between CAD models and downstream manufacturing process planning software typically involves redundant user interaction. Many existing tools are process-centric and unsuited for selection of a "best process" in the context of existing concurrent engineering design tools. A computer based Feature-Recognition (FR) process is developed to extract critical manufacturing features from engineering product CAD models. FR technology is used for automating the extraction of data from CAD product models and uses wire-frame geometry extracted from an IGES neutral file format. Existing hint-based feature recognition techniques have been extended to encompass a broader range of manufacturing domains than typical in the literature, by utilizing a combination of algorithms, each successful at a limited range of features. Use of wire-frame models simplifies product geometry and has the potential to support rapid manufacturing shape evaluation at the conceptual design stage. Native CAD files are converted to IGES neutral files to provide geometry data marshalling to remove variations in user modelling practice, and to provide a consistent starting point for FR operations. Wire-frame models are investigated to reduce computer resources compared to surface and solid models, and provide a means to recover intellectual property in terms of manufacturing design intent from legacy and contemporary product models. Geometric ambiguity in regard to what is ?solid? and what is not has plagued wire-frame FR development in the past. A new application of crossing number theory (CNT) has been developed to solve the wire-frame ambiguity problem for a range of test parts. The CNT approach works satisfactorily for products where all faces of the product can be recovered and is tested using a variety of mechanical engineering parts. Platform independent tools like Extensible Mark-up Language are used to capture data from the FR application and provide a means to separate FR and decision support applications. Separate applications are composed of reusable software modules that may be combined as required. Combining rule-based and case-based reasoning provides decision support to the manufacturing application as a means of rejecting unsuitable processes on functional and economic grounds while retaining verifiable decision pathways to satisfy industry regulators.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

<p>Detta examensarbete behandlar utformning av inredning i Bombardier Transportations tågmodell Regina. Arbetet omfattar en teknisk rapport med översikt av arbetsgången genom det utförda arbetet och de olika tillämpade tekniker som använts för att nå fram till slutgiltigt resultat. Arbetet omfattar även byggnation av en fullskalemodell vilken finns att beskåda på Mälardalens högskola i Eskilstuna.</p>

<p>Denna rapport beskriver ett projekt där målet är att att komma fram till vidareutveckling av mobil robotplattform, med attraktiv och förtroendegivande utseende, enligt uppdragsgivarens önskemål.</p><p> Projektet skulle resultera i en CAD-modell och modell i skala 1:10 som styrdes av ett antal krav från uppdragsgivaren i form av en kravspecifikation. </p><p> Projektet fortlöpte i huvudsak under vinter 2010 och är ett examensarbete för Högskoleingenjör inom Produktutveckling på Mälardalens Högskola.</p><p> Uppdragsgivarna på Robotdalen, som höll på att utveckla en mobil robotplattform, Opiflex, ville ha hjälp med redesign av detta. Vår uppgift handlade om att förbättra robotplattformen Opiflex så att den blir mer användarvänlig. Det fanns ett behov att ge robotplattformen mer attraktivt utseende och vidareutveckla vissa detaljlösningarna.</p><p> Projektavgränsningar berodde mest på tidsbrist. Begränsad tid tillät oss inte utveckla detaljlösningar för djupt.</p><p> Ett antal koncept togs fram av helhetsstilen för robotplattformen och därefter valdes ut de bästa koncepten. De två bästa koncepten utvecklades och kombinerades till slut ihop till den enda slutgiltiga konceptet.</p><p> Resultatet blev en CAD-modell som fick positiv reaktion av uppdragsgivare.</p><p> Vi anser att vi har lyckats med design av en produkt som utstrålar kvalitet och funktionalitet. Beviset på detta var uppdragsgivarens reaktion när de fick se konceptet redan i inledningsfasen. Vi fick en positiv feedback redan från början av konceptvalet och följaktligen kan vi påstå att våra lösningar har varit en bidragande orsak till produktens image.</p><p> </p>

<p>Denna rapport behandlar konstruktion och tillverkning av ett videokort till Versa Module Eurocard (VME) bussen. Kortet skall användas vid laborationer i kurser där mikrodatorkort VM42 från PEP Modular Computer används. Grafikkortet klarar en upplösning på minst 640x480 punkter med 24-bitars färg. Hela konstruktionen är uppbyggd kring Lattice^® MACH4A3-384/160. Designen av MACH kretsen är uppbyggd i Very High speed integrated hardware Description Language (VHDL) med hjälp av programmen ActiveHDL, Synplify Pro^®, ispDesignExpert samt LatticePRO. </p> / <p>This report is about the construction and fabrication of a video card for the Versa Module Euro card (VME) bus. The card will be used as a platform in laborations in courses including the VM42 microcontroller from PEP Modular Computer. The card is able to display a resolution of at least 640x480 pixels with 24bit color. The heart in the construction is the Lattice^® MACH4A3-384/160 Complex Programmable Logic Device (CPLD). All programming is done in Very High speed integrated hardware Description Language (VHDL) with the help of ActiveHDL, Synplify Pro^®, ispDesignExpert and LatticePRO software tools.</p>

An algorithm was developed to enable efficient segmentation of dimensionally-large objects into smaller components that can be fabricated within the given Rapid Prototyping (RP) machine workspace. The algorithm uses vertical and horizontal flat plane cuts, as well as feature-based volume decomposition. Due considerations were given to the optimisation of the surface accuracy, the build time, the strength and the number of segments generated by the segmentation process. A computer-aided design (CAD) application programme that interfaces with Unigraphics (UG) was also developed to allow import of objects in Standard Triangulated Language (STL) files into UG without loss of accuracy. In addition, the application software provides the functions that facilitate the implementation of the segmentation algorithm in UG. Two case studies were carried out using the algorithm in a Selective Laser Sintering (SLS) RP system. The resulting objects had properties that matched the research objectives with which the proposed algorithm was validated. / Singapore-MIT Alliance (SMA)

This research investigates and proposes methods to be used for the automation of the conceptual design phases of variational mechanisms. It employs the concept of feature-based modeling approaches. A method is proposed for integrating the dimensional synthesis, mechanical design and CAD generation phases with minimal designer intervention. Extended feature definitions are used in this research to create a smooth data transfer platform between different engineering tools and applications. This paper also introduces another method by which a set of dimensional data collected from a family of existing products is used to predict possible solutions for a new design. This method, based on artificial neural networks for training and solution generation, is used with optimization algorithms for the dimensional synthesis of mechanisms. An excavator arm mechanism is used as a case study to demonstrate these methods. The design of this mechanism is carried out based on its digging mode configurations. / Engineering Design