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Validação ágil e precisa de projetos conceituais de banco de dados; Agile and precise validation of conceptual database design

Broinizi, Marcos Eduardo Bolelli
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/12/2006 PT
Relevância na Pesquisa
46.25%
A criação do projeto conceitual de um bancos de dados que represente adequadamente um determinado domínio de aplicação continua sendo um dos principais desafios da área de banco de dados. Por outro lado, a discussão sobre métodos ágeis de desenvolvimento de software alcançou, recentemente, a comunidade de banco de dados. Este trabalho apresenta o projeto conceitual de bancos de dados sob a luz de métodos ágeis de desenvolvimento. Desenvolvemos uma extensão do arcabouço Naked Objects que permite uma validação ágil e precisa do projeto conceitual junto ao especialista do domínio. Em nossa abordagem, o projeto conceitual de bancos de dados é descrito por meio de anotações que representam as abstrações de dados em um ambiente dinâmico de validação.; Creating a conceptual database design that adequately represents a specific application domain continues to be one of the main challenges in the database research. On the other hand, the discussion regarding agile methods of software development has recently become a subject of interest to the database community. This work presents a new approach to create a conceptual database design according to agile methods. We have created an extension of the Naked Objects framework that allows an agile and precise validation of the conceptual database design by the domain specialist. In our approach...

OMPP para projeto conceitual de aeronaves, baseado em heurísticas evolucionárias e de tomadas de decisões; OMPP for conceptual design of aircraft based on evolutionary heuristics and decision making

Abdalla, Alvaro Martins
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/10/2009 PT
Relevância na Pesquisa
56.24%
Este trabalho consiste no desenvolvimento de uma metodologia de otimização multidisciplinar de projeto conceitual de aeronaves. O conceito de aeronave otimizada tem como base o estudo evolutivo de características das categorias imediatas àquela que se propõe. Como estudo de caso, foi otimizada uma aeronave de treinamento militar que faça a correta transição entre as fases de treinamento básico e avançado. Para o estabelecimento dos parâmetros conceituais esse trabalho integra técnicas de entropia estatística, desdobramento da função de qualidade (QFD), aritmética fuzzy e algoritmo genético (GA) à aplicação de otimização multidisciplinar ponderada de projeto (OMPP) como metodologia de projeto conceitual de aeronaves. Essa metodologia reduz o tempo e o custo de projeto quando comparada com as técnicas tradicionais existentes.; This work is concerned with the development of a methodology for multidisciplinary optimization of the aircraft conceptual design. The aircraft conceptual design optimization was based on the evolutionary simulation of the aircraft characteristics outlined by a QFD/Fuzzy arithmetic approach where the candidates in the Pareto front are selected within categories close to the target proposed. As a test case a military trainer aircraft was designed target to perform the proper transition from basic to advanced training. The methodology for conceptual aircraft design optimization implemented in this work consisted on the integration of techniques such statistical entropy...

Estudo e aplicação da metodologia TRIZ: desenvolvimento de um projeto conceitual para escolha de mancais para cabeçote de uma máquina de ultraprecisão; Development of a conceptual design of a set of bearings for application of ultra-precision machine spindle: a systemic approach creativity to solve problems by using TRIZ

Ximenes, Robert Dias
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 22/06/2011 PT
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56.17%
Este trabalho aborda o estudo e aplicação das ferramentas da metodologia TRIZ (Teoria da Resolução de Problemas Inventivos) aplicada na fase do projeto conceitual, no qual é desenvolvido um estudo de caso para escolha dos mancais, para cabeçotes de máquinas de corte do tipo "Dicing Saw". A metodologia TRIZ é direcionada para busca de idéias, através de uma abordagem sistemática da criatividade para a solução de problemas inventivos, consiste no reconhecimento da similaridade de um problema de projeto específico com um problema análogo, o qual tem uma solução conhecida no universo das patentes. É demonstrada a importância da capacidade de inovação como vantagem competitiva dentro do cenário atual, e como a TRIZ se apresenta como ferramenta sistêmica de suporte à criatividade inserida na fase de projeto conceitual, dentro do processo de desenvolvimento de produto. É desenvolvido um estudo de caso, no qual a TRIZ conduz à escolha sistemática de tipos de mancais apropriados, para eixos-árvore de alta velocidade para uma máquina denominada "Dicing Saw". O resultado da aplicação da TRIZ, dada as restrições operacionais foi a escolha de mancais aerostáticos porosos não-metálicos, os quais em conjunto com trabalhos na área de dinâmica de rotores foram manufaturados. A decisão pelo cabeçote com mancais aerostáticos porosos cerâmicos pode minimizar a influência de elevadas amplitudes de vibração durante usinagens sob alta rotação. Dessa forma...

Conjunto de procedimentos de engenharia reversa para projeto de banco de dados espaciais; Set of reverse engineering procedures for spatial database design

Matté, Lia Cláudia
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
56.28%
Projetos de SIG (Sistemas de Informação Geográfica), em geral, ainda não apresentam modelo conceitual de banco de dados geográficos. Os implementadores de SIG se preocupam com a aquisição dos dados (captura e adaptação), que é a etapa mais cara, e dão, ainda, pouca atenção à modelagem. A utilização de modelos conceituais faz com que os usuários controlem melhor sua base de dados e tirem maior proveito do SIG. O objetivo deste trabalho é definir um conjunto de procedimentos de engenharia reversa de bancos de dados espaciais que auxiliem na criação e manutenção de modelos conceituais para aplicações de SIG a partir de dados já existentes. Estes procedimentos podem contribuir para um aumento na qualidade dos SIG implementados, auxiliando na popularização da prática de modelagem conceitual de banco de dados geográficos. São estudados três formatos de transferência utilizados por usuários de SIG. A partir daí, é proposto uma arquitetura de sistema de engenharia reversa para SIG.; Even with the increasing use of Geographic Information Systems (GIS), conceptual modeling of geographic databases (GDB) is not yet usual among GIS professionals. This fact can in part be explained by the professional profile of most GIS designers. They usually are more familiar with specific GIS applications than with database technology. Among them...

Conceptual design and development of an automated co-generation system

Seabra, Eurico; Machado, José Mendes; Lima, Mário
Fonte: The National Institute for Research and Development in Mechatronics and Measuring Technique (INCDMTM) Publicador: The National Institute for Research and Development in Mechatronics and Measuring Technique (INCDMTM)
Tipo: Conferência ou Objeto de Conferência
Publicado em //2012 ENG
Relevância na Pesquisa
56.02%
Co-generation or Combined Heat and Power (CHP) is the simultaneous generation of both electricity and heat from the same fuel for useful purposes. The fuel varies greatly and can include coal, biomass, natural gas, nuclear material, the sun or heat stored in the earth. Co-generation (as a vector of energy efficiency) and renewable sources of energy possess their own set of low carbon benefits. Coupling co-generation and renewable sources contribute to a very strong proposition since it leads to the supply of both low-carbon electricity and low-carbon heat. In the case of co-generation plants fuelled by renewable energy sources, the low-carbon benefits of the heat are obvious since they derive from the renewable nature of the fuel. However, this also apply in the case of plants feed by other types of fuel. Such plants produce excess heat alongside electricity. When this heat, which is an unavoidable by-product, is used to satisfy an existing heat demand carbon dioxide (CO2) emissions are reduced overall, through a more efficient use of the fuel. The distributed generation systems produce energy close to the point of use, which typically doubles the efficiency in terms of fuel input‐to‐energy output ratio compared to conventional power generation in central plants. This means that the same amount of energy can be produced with half the amount of fuel...

Design conceptual na era pós-industrial. "A forma segue o conceito"

Ferreira, Patricia Colaço Santos
Fonte: Universidade Técnica de Lisboa. Faculdade de Arquitectura Publicador: Universidade Técnica de Lisboa. Faculdade de Arquitectura
Tipo: Dissertação de Mestrado
Publicado em /12/2010 POR
Relevância na Pesquisa
56.35%
Tese de Mestrado em Design de Produto; Ao longo das últimas duas décadas tem-se registado um acréscimo significativo no número de designers envolvidos numa prática que se aproxima da arte conceptual. A pertinência desta abordagem observa-se na discussão sobre o afastamento do design de produto da cultura de consumo, aproximando-se como referido inicialmente, de uma intenção artística, inclusive no jogo (intelectual) entre conceitos e práticas. O presente estudo pretende definir o conceito de design conceptual, dotando-o de uma base teórica de suporte à prática. É, portanto, a nossa intenção principal, clarificar o conceito de design conceptual, mapeando a originalidade desta abordagem, o que, por sua vez, permitirá elencar um conjunto de premissas orientadoras do processo criativo, distanciando-o do processo "clássico" de design e enfantizando a sua ligação à intencionalaidade artística. A metodologia de investigação adoptada permitiu construir o estado da arte, cruzando a crítica literária com entrevistas a designers portugueses e com a observação empírica de alguns projectos dos designers entrevistados. Os resultados do nosso estudo confirmaram a nossa hipótese e preencheram os objectivos inicialmente traçados. Ao verificarmos a aplicação do conceito na prática profissional de alguns designers...

Functional Modeling in Conceptual Die Design

Tor, Shu Beng; Britton, G.A.; Zhang, W.Y.
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Tipo: Artigo de Revista Científica Formato: 323859 bytes; application/pdf
EN_US
Relevância na Pesquisa
56.3%
The use of function has been recognized as an important part of the design process over last two decades, especially at the conceptual design stage, due to its critical role in determining the final product’s functionality. Although there are now some general methodologies dealing with functions or reasoning about functions, virtually no commercial CAD system can support conceptual design process due to their focus on geometrical modeling but not functional modeling. This paper presents a functional modeling approach to guide conceptual die design through functional reasoning steps including functional decomposition, functional supportive synthesis and function-structure mapping. The formed functional model provides a good basis to generate various die structures at the conceptual design stage, because function is a higher level of abstraction than structure, and helps to capture the designer’s intent. The functional modeling process has been implemented in a computerized design environment to expedite the conceptual die design process.; Singapore-MIT Alliance (SMA)

Performance-Driven Microfabrication-Oriented Methodology for MEMS Conceptual Design with Application in Microfluidic Device Design

Deng, Y.-M.; Lu, Wen Feng
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Tipo: Artigo de Revista Científica Formato: 205852 bytes; application/pdf
EN
Relevância na Pesquisa
66.25%
Performance and manufacturability are two important issues that must be taken into account during MEMS design. Existing MEMS design models or systems follow a process-driven design paradigm, that is, design starts from the specification of process sequence or the customization of foundry-ready process template. There has been essentially no methodology or model that supports generic, high-level design synthesis for MEMS conceptual design. As a result, there lacks a basis for specifying the initial process sequences. To address this problem, this paper proposes a performance-driven, microfabrication-oriented methodology for MEMS conceptual design. A unified behaviour representation method is proposed which incorporates information of both physical interactions and chemical/biological/other reactions. Based on this method, a behavioural process based design synthesis model is proposed, which exploits multidisciplinary phenomena for design solutions, including both the structural components and their configuration for the MEMS device, as well as the necessary substances for the chemical/biological/other reactions. The model supports both forward and backward synthetic search for suitable phenomena. To ensure manufacturability, a strategy of using microfabrication-oriented phenomena as design knowledge is proposed...

A multiobjective, multidisciplinary design optimization methodology for the conceptual design of distributed satellite systems

Jilla, Cyrus D., 1974-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 472 p.; 5937125 bytes; 5936869 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
46.28%
A multiobjective, multidisciplinary design optimization methodology for mathematically modeling the distributed satellite system (DSS) conceptual design problem as an optimization problem has been developed to advance the state-of-the-art in complex distributed satellite network design. An increasing number of space missions are utilizing DSS architectures in which multiple satellites work in a coordinated fashion to improve system performance, cost, and survivability. The trade space for distributed satellite systems can be enormous - too large to enumerate, analyze, and compare all possible architectures. The seven-step methodology enables an efficient search of the trade space for the best families of architectures, and explores architectures that might not otherwise be considered during the conceptual design phase, the phase of a DSS program in which the majority of lifecycle cost gets locked in. Four classes of multidisciplinary design optimization (MDO) techniques are investigated - Taguchi, heuristic, gradient, and univariate methods. The heuristic simulated annealing (SA) algorithm found the best DSS architectures with the greatest consistency due to its ability to escape local optima within a nonconvex trade space. Accordingly...

Design of an IT solution for distributed conceptual design processes; Design of an information technology solution for distributed conceptual design processes

Sim, Diana
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 19 leaves
ENG
Relevância na Pesquisa
46.24%
This thesis explores the need for software tools to aid in the conceptual stage of product design processes in a geographically distributed work environment. While the need for such a solution exists, there have been few strides to update the tools engineers currently use. The 2.009 design process is used as a model to better understand the particular needs of conceptual design. The intent of the study is to identify elements of a software solution that can support the design process. The structure of the design is a result of analysis of potential users as well as involvement in the type of design process to which the solution is intended to cater. The solution is motivated by recent advancements in internet and software technology. The final design addresses six important needs: communication of ideas, data and deadlines, general meeting scheduling, task force communication, scheduling, timeline and purpose, remote meeting, data & communication archival, and notification of design & communication changes. This thesis provides the preliminary research necessary to support the an IT design solution.; y Diana Sim.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.; Includes bibliographical references (leaf 16).

Colhedora beneficiadora de cebolas para a agricultura familiar: Projeto informacional e conceitual; Harvester-processed onions to the family farm: Informational and Conceptual Design

OLDONI, Andr??
Fonte: Universidade Federal de Pelotas; Agricultura familiar; Programa de P??s-Gradua????o em Sistemas de Produ????o Agr??cola Familiar; UFPel; BR Publicador: Universidade Federal de Pelotas; Agricultura familiar; Programa de P??s-Gradua????o em Sistemas de Produ????o Agr??cola Familiar; UFPel; BR
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
56.18%
The onion (Allium cepa L.) is considered of great social and economic importance in Brazil, and 70% of its production comes from family farmers. The production of onions is a tradition passed from generation to generation among the farmers, using simple tools and machines for the implementation of the crop. The physical exertion demanded, especially in transplant and harvest stages, which are carried out entirely by hand, is quite large. Usually the manufacturers of agricultural machinery have no interest in this sector. The aim of this study was to develop a mechanized system for the purpose of harvesting and benefit onions adapted to needs of family farmers. The methodology used is based on a phase model which is divided into: informational design, conceptual design, preliminary design and detailed design, and performed this work is the first two. In the first phase, informational design, we identified the needs of clients according to the functions that develop within each phase of the life cycle of the product to establish the design specifications. In the conceptual design phase there was the scope of the problem, establishing the functional structures feasible to meet the design specifications. There were searches for solution principles...

Tool based supporting collaborative design from specification development to CAD modelling

FREY, Estelle; OSTROSI, Egon; GOMES, Samuel; ROUCOULES, Lionel
Fonte: TMCE (Tools and Methods of Competitive Engineering) Publicador: TMCE (Tools and Methods of Competitive Engineering)
EN
Relevância na Pesquisa
46.3%
Management of dynamic information interdependencies and as well as management of multiple perspectives from specification development to conceptual design, as well as from conceptual design to detailed design are critical elements of collaborative and distributed design. Supporting collaborative design with computer technology is a strategy to enhance the ability of actors to interact with each other and with computational resources during different phases of product design and development. However, many observations from the industry and research support the evidence that both specification development phase and conceptual design are poorly supported by collaborative tools. Furthermore, though CAD tools support detail design, it is imperative to develop new collaborative design tools or renovate traditional standalone CAD systems by making it collaborative-native. Consequently, the first goal of this paper is to propose the development of collaborative tools related to the conceptual design. The second goal is the development of a mechanism for communication between the developed collaborative conceptual design tools and actually CAD tools. The mechanism and architecture of the developed tool for collaborative conceptual design is presented. A design problem illustrates the concepts discussed in the paper.

Role of sketching in conceptual design of car styling

BOUCHARD, Carole; AOUSSAT, Améziane; DUCHAMP, Robert
Fonte: Inderscience Publisher Publicador: Inderscience Publisher
EN
Relevância na Pesquisa
56.02%
This paper aims at studying the role of sketching in car styling. Prior studies have shown that sketches play a major role in the early phases of design. A definition of the intermediate representations and mental representations will enable a better understanding of how sketches are produced. Two distinct experiments are proposed: a series of interviews of 40 professional car designers and a protocol study with six junior car designers. A comparative study demonstrated that two main phases appear in the specific car design process, including ‘routine’ and ‘non routine’ activities linked with external inspiration sources.; EUNET

Comparison of different Multiple-criteria decision analysis methods in the context of conceptual design: application to the development of a solar collector structure

EL AMINE, Mehdi; PAILHES, Jérôme; PERRY, Nicolas
Fonte: Arts et Métiers ParisTech Publicador: Arts et Métiers ParisTech
EN_US
Relevância na Pesquisa
66.28%
At each stage of the product development process, the designers are facing an important task which consists of decision making. Two cases are observed: the problem of concept selection in conceptual design phases and, the problem of pre-dimensioning once concept choices are made. Making decisions in conceptual design phases on a sound basis is one of the most difficult challenges in engineering design, especially when innovative concepts are introduced. On the one hand, designers deal with imprecise data about design alternatives. On the other hand, design objectives and requirements are usually not clear in these phases. The greatest opportunities to reduce product life cycle costs usually occur during the first conceptual design phases. The need for reliable multi-criteria decision aid (MCDA) methods is thus greatest at early conceptual design phases. Various MCDA methods are proposed in the literature. The main criticism of these methods is that they usually yield different results for the same problem. In this work, an analysis of six MCDA methods (weighed sum, weighted product, Kim & Lin, compromise programming, TOPSIS, and ELECTRE I) was conducted. Our analysis was performed via an industrial case of solar collector structure development. The objective is to define the most appropriate MCDA methods in term of three criteria: (i) the consistency of the results...

Critical review of multi-criteria decision aid methods in conceptual design phases: application to the development of a solar collector structure

EL AMINE, Mehdi; PAILHES, Jérôme; PERRY, Nicolas
Fonte: Springer Publicador: Springer
EN
Relevância na Pesquisa
66.28%
At each stage of the product development process, the designers are facing an important task which consists of decision making. Two cases are observed: the problem of concept selection in conceptual design phases and, the problem of pre-dimensioning once concept choices are made. Making decisions in conceptual design phases on a sound basis is one of the most difficult challenges in engineering design, especially when innovative concepts are introduced. On the one hand, designers deal with imprecise data about design alternatives. On the other hand, design objectives and requirements are usually not clear in these phases. The greatest opportunities to reduce product life cycle costs usually occur during the first conceptual design phases. The need for reliable multi-criteria decision aid (MCDA) methods is thus greatest at early conceptual design phases. Various MCDA methods are proposed in the literature. The main criticism of these methods is that they usually yield different results for the same problem [22,23,25]. In this work, an analysis of six MCDA methods (weighed sum, weighted product, Kim & Lin, compromise programming, TOPSIS, and ELECTRE I) was conducted. Our analysis was performed via an industrial case of solar collector structure development. The objective is to define the most appropriate MCDA methods in term of three criteria: (i) the consistency of the results...

Discussing the design through drawing: transitional desire and procedural trajectories

Magalhães, Graça Maria Alves dos Santos
Fonte: ICDHS Design History and Design studies Publicador: ICDHS Design History and Design studies
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
56.12%
Design represents the commitment of the artificial with nature – the artifact as symbolic cultural representation. Herein, drawing is the skill activity of the designer as renewed desire it transforming the world. Therefore, drawing is the material of design as medium of the representation, such as technical and interpretive expression of the author's imagination from an external program (brief). Hence, we propose drawing as a path performed by author’s desire that symbolically reveals the subject of design in a specific level. The artifact as primordial income for the conceptual design process comes out of the drawing tools as practice that elevates the cultural representation. The pattern of drawing can be, symmetrical or asymmetrical, the link that joins two levels of the artifact, instrumental and critical, it becoming the basis for design’s narrative. In this case, drawing skills convey and supporting the cultural expression showing design as a particular and symbolic cultural artifact. As context we refer the analysis of representative designers in the Portuguese geographic and cultural environment. We hypothesized that cultural and symbolic features result according to the artifact’s identity. We seek the goal of the analysis according to the significance of drawing in the discipline of design. This research intends to scientifically integrate the ontological analysis of drawing in relation to design through the presented Portuguese examples.; O design representa o compromisso do artificial – o artefacto como representação simbólica cultural – com a realidade natural através da mediação do desenho enquanto renovado desejo de transformação. Por isso...

An academic design methodology for electrical mobility products - from necessity to functional prototype

Osorio G??mez, Gilberto; Mej??a Guti??rrez, Ricardo; Sierra Zuluaga, Luis Fernando
Fonte: Grupo de Investigaci??n en Ingenier??a de Dise??o - GRID; Design Engineering Research Group - GRID; Escuela de Ingenier??a Publicador: Grupo de Investigaci??n en Ingenier??a de Dise??o - GRID; Design Engineering Research Group - GRID; Escuela de Ingenier??a
Tipo: conferenceObject; Documento de conferencia; publishedVersion
ENG
Relevância na Pesquisa
55.94%
The undergraduate program in Product Design Engineering at EAFIT University-Colombia, includes an applied project course during eight semesters with different topics -- Students attend their last project course in seventh and eighth semester integrated into one year topic -- In this project, they have to design a new high-tech consumer product in electrical mobility for different types of transportation need and to construct a completely functional prototype -- The objectives of these courses are to focus on the triad of ???Product-User-Context??? as well as to foster design, engineering, manufacturing, management and entrepreneurship skills -- In order to offer a systematic way of working, and to obtain better results, a systematic design methodology has been adopted, adapted and applied during the whole product development process in order to facilitate representation, analysis, calculation, management and control of the information related to the product -- The methodology is broadly explained through activities, tools, information and results related to four main stages: 1) Need research & problem statement, 2) Conceptual design, 3) Detailed design and 4) Prototype construction & testing -- A successful case study is presented following all the stages of the presented methodology for the development of an Electric Power-Assisted Bicycle

Projeto conceitual de uma aeronave de aviação geral e análise de compromissos; A conceptual design of general aviation aircraft and analysis of commitments

Abdalla, Alvaro Martins
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 19/11/2004 PT
Relevância na Pesquisa
66.21%
Busca-se encontrar a solução de compromissos para o desenvolvimento de uma aeronave multifuncional, de aviação geral, a pistão, que atenda às necessidades do mercado brasileiro e cujas características de desempenho estejam próximas ou superiores às das aeronaves típicas da aviação geral que operam nos Estados Unidos e Brasil. O objetivo principal do trabalho consistiu em desenvolver uma metodologia para projetos conceituais de aeronaves de pequeno porte e de uma família de aeronaves de forma que a geradora da família possa ser facilmente convertida em configurações diferentes, conservando o maior número de partes em comum, mantendo as características de desempenho almejadas e cumprindo com os requisitos de certificação impostos para a categoria. Apresentam-se definições, conhecimentos e técnicas na área de projetos aeronáuticos e descrevem-se de forma sucinta os aspectos mais importantes que envolvem o projeto conceitual. Em seguida é exposta a metodologia utilizada e são definidos os objetivos e os compromissos. Finalmente são apresentadas tabelas geradas pelo software PCA-Projeto Conceitual de Aeronaves e gráficos contendo as caracterizações onde se enquadra o objeto de estudo, a discussão e as conclusões da investigação.; The purpose of this work is to derive compromise solutions for the conceptual design of a general aviation aircraft...

Cost-Effective Conceptual Design Using Taxonomies

Vakilian, Ali; Chodpathumwan, Yodsawalai; Termehchy, Arash; Nayyeri, Amir
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/03/2015
Relevância na Pesquisa
46.29%
It is known that annotating named entities in unstructured and semi-structured data sets by their concepts improves the effectiveness of answering queries over these data sets. As every enterprise has a limited budget of time or computational resources, it has to annotate a subset of concepts in a given domain whose costs of annotation do not exceed the budget. We call such a subset of concepts a {\it conceptual design} for the annotated data set. We focus on finding a conceptual design that provides the most effective answers to queries over the annotated data set, i.e., a {\it cost-effective conceptual design}. Since, it is often less time-consuming and costly to annotate general concepts than specific concepts, we use information on superclass/subclass relationships between concepts in taxonomies to find a cost-effective conceptual design. We quantify the amount by which a conceptual design with concepts from a taxonomy improves the effectiveness of answering queries over an annotated data set. If the taxonomy is a tree, we prove that the problem is NP-hard and propose an efficient approximation and pseudo-polynomial time algorithms for the problem. We further prove that if the taxonomy is a directed acyclic graph, given some generally accepted hypothesis...

Conceptual design for a laminar-flying-wing aircraft

Saeed, Tariq Issam
Fonte: University of Cambridge; Department of Engineering Publicador: University of Cambridge; Department of Engineering
Tipo: Thesis; doctoral; PhD
EN
Relevância na Pesquisa
46.23%
The laminar-flying-wing aircraft appears to be an attractive long-term prospect for reducing the environmental impact of commercial aviation. In assessing its potential, a relatively straightforward initial step is the conceptual design of a version with restricted sweep angle. Such a design is the topic of this thesis. In addition to boundary layer laminarisation (utilising distributed suction) and limited sweep, a standing-height passenger cabin and subcritical aerofoil flow are imposed as requirements. Subject to these constraints, this research aims to: provide insight into the parameters affecting practical laminar-flow-control suction power requirements; identify a viable basic design specification; and, on the basis of this, an assessment of the fuel efficiency through a detailed conceptual design study. It is shown that there is a minimum power requirement independent of the suction system design, associated with the stagnation pressure loss in the boundary layer. This requirement increases with aerofoil section thickness, but depends only weakly on Mach number and (for a thick, lightly-loaded laminar flying wing) lift coefficient. Deviation from the optimal suction distribution, due to a practical chamber-based architecture...