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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.
1

Investigation of the viscous resistance components of catamaran forms

Utama, I. Ketut Aria Pria January 1999 (has links)
No description available.
2

Parametric representation of hull painted surfaces and the correlation with fluid drag

Dey, Swapan Kumar January 1989 (has links)
No description available.
3

Concrete as a fabrication material for simple hulls : A marine innovation study

Harrington, K. January 1987 (has links)
No description available.
4

Theoretical and experimental studies on the resistance of SWATH ships

Chun, Ho Hwan January 1988 (has links)
No description available.
5

Medição de superfície submersa de embarcação com sistema ótico de precisão a laser. / Hull surface measurement by laser optics precision system.

Grinberg, Marcelo 14 March 2013 (has links)
A medição de superfícies através de sistemas óticos de precisão é aplicável em diversas áreas da engenharia naval e oceânica: levantamento de geometria de casco para a determinação da estabilidade estática de embarcações in loco, verificação de processos construtivos, recuperação de planos de linha originais perdidos, arqueologia naval, inspeção de cabos e estruturas submersas, planejamento de rota de mergulho, entre outras. Os dispositivos óticos de precisão disponíveis são de alto custo, e a necessidade de se desenvolver um dispositivo de baixo custo se faz presente. O propósito deste trabalho é a criação de metodologia de obtenção de superfície através de procedimento prático experimental. A varredura tridimensional de superfície é feita experimentalmente através da utilização de leitor tridimensional a laser. A contribuição deste trabalho é de promover um conceito teórico a uma prova experimental do conceito, utilizando-se de recursos da automação e robótica, e programação com linguagem e software aplicativo de baixo custo e largamente disponível. / The surface measurement using precision optics is applicable in many areas of naval engineering: survey of hull geometry to determine the static stability of vessels on the spot, verification of construction processes, recovery of lost original hull plans, naval archeology, inspection of underwater structures and cables, route planning diving, among others. The precision optical devices available are expensive, and the need to develop a low-cost device is present. The purpose of this work is to create a methodology for obtaining surfaces through practical experimental procedure. The three-dimensional scan surface is made experimentally by using three-dimensional laser reader. The contribution of this work is to promote a theoretical concept to an experimental proof of concept, using the resources of automation and robotics, and software programming language and application of lowcost and widely available.
6

Optimisation of parametric equations for shock transmission through surface ships from underwater explosions

Elder, David James, d.elder@crc-acs.com.au January 2006 (has links)
Currently shock effects on surface ships can be determined by full scale shock trials, Finite Element Analysis or semi empirical methods that reduce the analytical problem to a limited number of degrees of freedom and include hull configurations, construction methods and materials in an empirical way to determine any debilitating effects that an explosion may have on the ship. This research has been undertaken to better understand the effect of hull shape on surface ships' shock response to external underwater explosions (UNDEX). The study is within the semi empirical method category of computations. A set of simple closed-form equations has been developed that accurately predicts the magnitude of dynamic excitation of different 2- D rigid-hull shapes subject to far-field UNDEX events. This research was primarily focused on the affects of 2-D rigid hull shapes and their contribution to global ship motions. A section of the thesis,
7

Medição de superfície submersa de embarcação com sistema ótico de precisão a laser. / Hull surface measurement by laser optics precision system.

Marcelo Grinberg 14 March 2013 (has links)
A medição de superfícies através de sistemas óticos de precisão é aplicável em diversas áreas da engenharia naval e oceânica: levantamento de geometria de casco para a determinação da estabilidade estática de embarcações in loco, verificação de processos construtivos, recuperação de planos de linha originais perdidos, arqueologia naval, inspeção de cabos e estruturas submersas, planejamento de rota de mergulho, entre outras. Os dispositivos óticos de precisão disponíveis são de alto custo, e a necessidade de se desenvolver um dispositivo de baixo custo se faz presente. O propósito deste trabalho é a criação de metodologia de obtenção de superfície através de procedimento prático experimental. A varredura tridimensional de superfície é feita experimentalmente através da utilização de leitor tridimensional a laser. A contribuição deste trabalho é de promover um conceito teórico a uma prova experimental do conceito, utilizando-se de recursos da automação e robótica, e programação com linguagem e software aplicativo de baixo custo e largamente disponível. / The surface measurement using precision optics is applicable in many areas of naval engineering: survey of hull geometry to determine the static stability of vessels on the spot, verification of construction processes, recovery of lost original hull plans, naval archeology, inspection of underwater structures and cables, route planning diving, among others. The precision optical devices available are expensive, and the need to develop a low-cost device is present. The purpose of this work is to create a methodology for obtaining surfaces through practical experimental procedure. The three-dimensional scan surface is made experimentally by using three-dimensional laser reader. The contribution of this work is to promote a theoretical concept to an experimental proof of concept, using the resources of automation and robotics, and software programming language and application of lowcost and widely available.
8

Variations of Shape in Industrial Geometric Models

Veelo, Bastiaan Niels January 2004 (has links)
<p>This thesis presents an approach to free-form surface manipulations, which conceptually improves an existing CAD system that constructs surfaces by smoothly interpolating a network of intersecting curves. There are no regularity requirements on the network, which already yields superior modelling capabilities compared to systems that are based on industry-standard NURBS surfaces.</p><p>Originally, the shape of such a surface can be modified only locally by manipulating a curve in the network. In this process there is an inherent danger that the curve is being pulled away from intersections that it has with other curves. When this happens, the network is invalidated as a surface representation, and many curves may have to be adjusted to restore network consistency and surface quality. This thesis contributes a method that solves these problems by propagating changes that are made in one curve to curves in its vicinity. How and to what extent curves react to changes is controlled by two parameters that can be varied along the curve that is being manipulated. Any curve may be constrained in one or more degrees of freedom. The integrity of the curve network is implicitly conserved, as well as the geometric continuity of the surface.</p><p>The result is a tool for the modification of curve-interpolating surfaces, which can easily be applied to large areas on models with any level of detail. This allows designers to concentrate on the creative process, rather than on planning chains of actions. They can explore different design variations, optimise shapes further, and generally be more productive.</p> / <p>Dette doktorgradsarbeidet presenterer en fremgangsmåte for formgivning og modifisering av datamaskinbaserte, skulpturerte flater. Metoden forbedrer et eksisterende system for data-assistert konstruksjon (DAK) som bygger dobbeltkrummede flater ved å interpolere et nettverk av skjærende kurver. Nettverket trenger ikke være regelmessig, noe som allerede gir bedre modelleringsmuligheter sammenliknet med systemer som er basert på standard NURBS flater.</p><p>En slik flate kan opprinnelig bare endres lokalt ved å dra i en kurve. I denne prosessen er det fare for at kurven blir dratt fra skjæringspunkter den har med andre kurver. Hvis dette skjer, representerer ikke nettverket en flate lenger, og mange kurver må justeres for å få tilbake integriteten i nettverket og kvaliteten i formen. Denne avhandlingen bidrar med en metode som løser disse problemene ved å spre endringer som blir gjort i en kurve til andre kurver i nærheten. Hvordan og i hvilken utstrekning kurvene reagerer på endringen styres av to parametre som kan varieres langs kurven som blir endret. Enhver kurve kan låses i en eller flere frihetsgrader. Integriteten til nettverket samt glattheten i formen blir bevart automatisk.</p><p>Resultatet er et redskap for modifikasjon av kurve-interpolerende flater som med letthet kan brukes på større områder av modeller med hvilken som helst grad av detalj. Dette gir designere muligheten til å konsentrere seg om det kreative, istedenfor å planlegge handlingsrekker. De kan utforske forskjellige designvariasjoner, optimalisere former ytterligere, og i det hele tatt være mer produktive.</p>
9

Variations of Shape in Industrial Geometric Models

Veelo, Bastiaan Niels January 2004 (has links)
This thesis presents an approach to free-form surface manipulations, which conceptually improves an existing CAD system that constructs surfaces by smoothly interpolating a network of intersecting curves. There are no regularity requirements on the network, which already yields superior modelling capabilities compared to systems that are based on industry-standard NURBS surfaces. Originally, the shape of such a surface can be modified only locally by manipulating a curve in the network. In this process there is an inherent danger that the curve is being pulled away from intersections that it has with other curves. When this happens, the network is invalidated as a surface representation, and many curves may have to be adjusted to restore network consistency and surface quality. This thesis contributes a method that solves these problems by propagating changes that are made in one curve to curves in its vicinity. How and to what extent curves react to changes is controlled by two parameters that can be varied along the curve that is being manipulated. Any curve may be constrained in one or more degrees of freedom. The integrity of the curve network is implicitly conserved, as well as the geometric continuity of the surface. The result is a tool for the modification of curve-interpolating surfaces, which can easily be applied to large areas on models with any level of detail. This allows designers to concentrate on the creative process, rather than on planning chains of actions. They can explore different design variations, optimise shapes further, and generally be more productive. / Dette doktorgradsarbeidet presenterer en fremgangsmåte for formgivning og modifisering av datamaskinbaserte, skulpturerte flater. Metoden forbedrer et eksisterende system for data-assistert konstruksjon (DAK) som bygger dobbeltkrummede flater ved å interpolere et nettverk av skjærende kurver. Nettverket trenger ikke være regelmessig, noe som allerede gir bedre modelleringsmuligheter sammenliknet med systemer som er basert på standard NURBS flater. En slik flate kan opprinnelig bare endres lokalt ved å dra i en kurve. I denne prosessen er det fare for at kurven blir dratt fra skjæringspunkter den har med andre kurver. Hvis dette skjer, representerer ikke nettverket en flate lenger, og mange kurver må justeres for å få tilbake integriteten i nettverket og kvaliteten i formen. Denne avhandlingen bidrar med en metode som løser disse problemene ved å spre endringer som blir gjort i en kurve til andre kurver i nærheten. Hvordan og i hvilken utstrekning kurvene reagerer på endringen styres av to parametre som kan varieres langs kurven som blir endret. Enhver kurve kan låses i en eller flere frihetsgrader. Integriteten til nettverket samt glattheten i formen blir bevart automatisk. Resultatet er et redskap for modifikasjon av kurve-interpolerende flater som med letthet kan brukes på større områder av modeller med hvilken som helst grad av detalj. Dette gir designere muligheten til å konsentrere seg om det kreative, istedenfor å planlegge handlingsrekker. De kan utforske forskjellige designvariasjoner, optimalisere former ytterligere, og i det hele tatt være mer produktive.
10

Laivo korpuso detaliu gamybos optimizavimas / Optimization of ship hull production

Panasiuk, IRINA 01 March 2013 (has links)
Laivų projektavimo ir statybos magistrantūros studijų programa / darbo vadovas doc. dr. L. Turkina; Klaipėdos universitetas, Jūrų technikos fakultetas. – 2011. – 45 p. Baigiamajame magistro darbe nagrinėjama galimybė optimizuoti laivo korpuso kreivalinijinių detalių gamybą. Tradiciškai laivų statyboje sunkiausia optimizuoti korpuso gamybos technologinį procesą. Tačiau būtent korpuso gamybos kaina sudaro 30 % laivo savikainos. Todėl darbe buvo nuspręsta išanalizuoti UAB Vakarų Baltijos laivų statyklos (VBLS) detalių gamybos technologinį procesą ir pasiūlyti laivo korpuso kreivalinijinių detalių gamybos optimizavimo metodą. Mūsų šalyje lakštinio metalo apdirbimo automatizavimo lygis yra aukštas. Tačiau kalbant apie kreivalinijinių profilių gamybos procesą, mūsų gamyklos ženkliai atsilieka nuo pirmaujančių pasaulio laivų statyklų. Taip kiekviename gamybos etape kaupiasi formų ir matmenų nukrypimai. Defektų taisymas yra daug brangesnis nei gamybos savikaina, tačiau iki šiol net 35 % sekcijų gamybos apimties sudaro defektų taisymo ir tvarkymo darbai. Darbo imlumo sumažinimas ir gaminamų laivų korpuso konstrukcijų tikslumo padidinimas yra pagrindinis optimizavimo uždavinys, nuo kurio priklauso šiuolaikinės laivų statybos konkurencingumas. Darbą sudaro įvadas, 3 skyriai, išvados ir rekomendacijos, literatūros sąrašas. Atskirai pridedami darbo priedai. / Panasiuk I. Optimization of ship hull production: Master of naval architecture and marine engineering/ reseach advisor PhD, assoc. prof. L.Turkina; Klaipeda University, the Faculty of Marine Engineering. – 2011. – 45p. The final master paper deals with the possibility of ship hull’s curvilinear profile production optimization. Traditionally in shipbuilding the hardest to optimize is the hull construction, but it is 30% of ship price. In this paper was analyzing the VBLS technological process of profile production and offer a method to improve the curvilinear profile production. There is the high autoimmunization technological level of steel plate production in VBLS, but curvilinear profile production is not effective. In the every part of ship hull production are concentrate defects. The repairs cost are highly than production and now it is 35% of ship sub-assembly work. The aim of the research was to rationalize manufacturing and improve shipbuilding productivity. Work consists of introduction, 3 parts, conclusions and suggestions, references. Appendixes included.

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