• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 165
  • 75
  • 48
  • 20
  • 11
  • 8
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 384
  • 98
  • 78
  • 63
  • 51
  • 46
  • 41
  • 38
  • 36
  • 36
  • 34
  • 32
  • 31
  • 30
  • 30
  • 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.
181

THE HUMAN SCALE IN THE PUBLIC SPACE - LINGUA FRANCA / THE HUMAN SCALE IN THE PUBLIC SPACE

Tjärnberg, Cecilia Margareta January 2017 (has links)
In this degree project I’m designing furniture for the human scale in the public space. More specifically for parks and squares in the city. As I am defining the human scale I am inspired by two main sources; the documentary Alive inside(2014) och Peter Gärdenfors Tankens vindlar(2005). The most important part of this definition is its inner logic, the idea that the human scale consists of two parts, that it is  in size close to mine  in spirit  personal. The first part determines proportion as related to the human body and the other describes the form essens. Through the workshop I gather the relevant data that gives form to the spirit, that is personal. In the workshop held with six elderly people in a home in the suburbs of Uppsala, we sat down and listened to music and worked with clay for one hour. The hand made clay sculptures are scanned and so digitalised and available for digital fabrication. This method of working with the design and production is also an attempt to work towards industrial production. So to make the design available for the city by avoiding high cost production. The data have been adjusted using Meshmixer and then realised physically through a collaboration with Scania and their large scale 5-axis CNC machine. The result is two pieces of furniture; one bench and one platform. In this first section of the report, under the title Contextualising and investigative discussion, I will describe to you why this project is important. Important to us, as people living our lives in the evolving city, creating a social standard or a social tradition together in the public space. In the next section, under the title Method of Work, I’ll go in to more extended detail describing separate parts of the design process as I’ll go through the practical aspects. In the third section, under the title The Concept and Implementing, I will sum up my initial thoughts in relation to the new information the project have generated.
182

Desenvolvimento de apalpador de contato elétrico (\"touch trigger probe\") para atuação no processo de torneamento / Devefopment of a low cost touch trigger probe for CNC lathes

Del Guerra, Marcelo 21 September 2004 (has links)
A utilização dos apalpadores acoplados a máquinas CNC se tornou uma realidade muito comum no mundo atual, principalmente devido à diminuição do tempo de preparação e possibilidades de realização de medições na própria máquina-ferramenta. Porém, ainda existem algumas barreiras a se transpor, como por exemplo, a dificuldade de programação, custo relativamente elevado e pouca literatura que trata exclusivamente a respeito da utilização dos apalpadores para medição nas máquinas-ferramentas. Nesse trabalho é realizada uma revisão bibliográfica sobre o uso dos apalpadores em ambiente industrial, discutindo-se as tecnologias utilizadas na geração do sinal de \"trigger\" e é proposto um novo modelo de apalpador de contato elétrico, de baixo custo, desenvolvido especialmente para atender as necessidades de medições em tornos CNC. Os testes em laboratório revelaram que a repetibilidade do protótipo construído foi de 0,003 mm dentro de uma confiabilidade de mais ou menos 3 \'sigma\' ou 99,73%. Concluiu-se que tais características são altamente compatíveis com os requisitos necessários para a maioria dos processos de torneamento. / The use of touch trigger probes attached to CNC machines has become a world standard, especially due the reduction of setup time and the ability to promote work piece measurements on machine. However, some barriers like measurement routines programming difficulties, high costs of these equipments and the low number of technical literature about this subject, still need to be transposed. This work presents a review on the applications of touch trigger probes on companies shop floor, discussing the nowadays technologies used to generate the trigger signal. A new touch trigger probe model based on a simple electrical contact is specially developed to provide the measuring characteristics required for Lathes, with the needed characteristics and low cost. The tests of the probe developed in the laboratory shown a repeatability of 0,003 mm (more and less 3 \'sigma\' or 99,73%). Those characteristics are high compatible with the most needs of the industry.
183

A model for analysis and design of an integrated operations management system using systems engineering approach: A case study / En modell för analys och design av ett system för integrerad verksamhets-styrning med hjälp av systems engineering: En fallstudie

Thalji, Idriss, Zubair, Gaith January 2007 (has links)
<p>Background: Generally, operation management includes a set of complicated systems interfacing each other. Most important systems which impact and impacted by the operations management system are production management system and maintenance management system. But to treat the interfacing losses has been difficult as interact and partially overlap each other. In this study, case-operational system was treated with developed model that analysis and design integrated operational system in order to make it easier and cost effective to manage.</p><p>Methods: A model was developed based on latest literature survey work using systems paradigm methodology and systems engineering approach.</p><p>Results: Among five analysis techniques, four types of interfacing losses were identified, seven requirements were extracted, nine conceptual solutions were generated, one of them was selected and based on it the integrated operational management system were designed.</p><p>Conclusions: The results suggest that the operational system in case-company shall be integrated by organization management, process management, and control management, in addition to data management.</p> / <p>Bakgrund: I allmänhet har operations verksamhet en del komplicerade system där friktion kan förekomma. De viktigaste systemen som har påverkan på operations verksamhet är produktion och underhålls system. Att behandla friktions förluster har varit svårt eftersom de både samverkar och delvis överlappar varandra. I dem här studien har olika fall av operationssystem behandlats med att först utveckla en modell, analysera och designa den integrerade operationssystemet för att få den billigaste och dem mest kostnads effektiva sätt att klara av.</p><p>Metod: En modell har utvecklats baserat på de senaste metoderna genom att använda system paradigm metoder och systemtekniska angreppssätt.</p><p>Resultat: Genom att använda fem sätt att analysera, sju bestämmelser extraherade, nio lösningar generade, valdes en av lösningarna och med lösningen som grund designades operations verksamhet.</p><p>Slutsats: Resultatet förslog att operations verksamhet skall integrera organisation, process och kontroll ledningar och inte bara data ledningen.</p>
184

中國英語新聞頻道CNC World在軟實力發展脈絡下如何選擇新聞框架 / CNC World and China’s Soft Power How CNC World reports major global agenda

曾宜年, Zeng, Ellen Unknown Date (has links)
隨著中國在國際場域上地位的崛起,一方面為了消弭其他國際強權的防備之心,另一方面在經濟的驅動力之下,中國意識到國際形象的重要,於是近年來「軟實力」開始成為中國政府的重點政策。根據美國學者Joseph S. Nye,軟實力指的是一個國家對於國際公眾的吸引力,這樣的吸引力可能來自於文化資產、政治的意識形態以及形塑國際議題方向的能力。媒體通常在軟實力中扮演著重要的角色,像是CNN、Al Jazeera就分別為美國和阿拉伯國家帶來影響國際輿論的能力。2010年,新華社創立了一個新的國際新聞頻道CNC World,便是因應軟實力的需求而生,期許CNC World能和CNN、BBC、Al Jazeera等國際新聞頻道分庭抗禮,不僅僅有主導國際議題的能力,更能在國際事件中,將所謂的「中國觀點」傳播出去。因此新華社投入了巨額的資金在CNC World上,並且在財務結構上改革,允許49% 的私人投資,藉以昭示CNC World的新聞內容不受中國政府的檢查制度介入,旨在提供國際觀眾「公正」、「客觀」與具有「中國觀點」的國際新聞。 本論文欲探討,CNC World是否在軟實力的時代脈絡下,在建構新聞事件上真的有所調整。因此本論文比較CNC World和另外一個全然由中國政府出資的國際新聞台CCTV 9,以及國際主流新聞頻道CNN,在七件國際重大議題上的報導架構,去觀察CNC World如何平衡中國政府的偏好和國際觀眾的期待。研究結果發現,CNC World相較另外兩個新聞頻道,在修辭以及題材的選擇上都較為中立,而對於「中國觀點」CNC World也有獨樹一格的闡述方式。但是研究結果也反映,無論是CNC World、CCTV 9 或是CNN 都無法脫離其主要資金提供者那隻「看不見的手」來左右新聞的框架。 / CNC World is an international news channel of China established in July 2010 with a mission of the changing China. Under the current international political context of a rising China, the Chinese government started to emphasize on the development of its soft power. One of the abilities that China wants to obtain is the power to influence the worldwide audience’s conception of the major global agenda and their perception toward certain countries’ images. This is the context in which CNC World is established. The Xinhua News Agency has invested unprecedentedly in CNC World to ensure its success. In addition, to assure CNC World’s news credibility, the financial structure of CNC World is reformed to have a government hands-off editorial board. This thesis compares CNC World’s news reporting with CCTV 9 and CNN International, aiming to find out how CNC World adjusts its news coverage on the major global agenda under the soft power context. Seven current global issues are included in the study: South China Sea Dispute between China and Vietnam, US Currency Bill on China, Palestinian Statehood bin in UN, The Fall of Gaddafi, Arab Spring in Egypt, Greece Debt Crisis, and The Killing of Osama bin Laden. The result shows that CNC World tends to use a relatively neutral way to report these issues and it has indeed found a unique way to present the Chinese perspective. However, that the international news represents its funding providers’ positions remains the same.
185

TÉCNICAS DE SEGMENTAÇÃO DE IMAGENS NA GERAÇÃO DE PROGRAMAS PARA MÁQUINAS DE COMANDO NUMÉRICO / SEGMENTING TECHNIQUES OF IMAGES IN THE GENERATION OF PROGRAMS FOR MACHINERY OF COMMAND NUMERICAL

Morgan, Jolvani 14 April 2008 (has links)
This work describes a tool for extraction of features in 2D images applied to industrial automation. The method uses techniques implemented targeting of images into pieces model as detection of edges in the extraction of spatial coordinates of the image and import applications in CAD (Computer-Aided Design) for the generation of programmers for Computer Numerical Control (CNC). This work is to copy a particular model (image) from an existing object, which features a process of reverse engineering. An initial prototype was developed using the Java language with the Eclipse IDE and library for handling complex images, the API Java Advanced Image (JAI). For the acquisition of parts to be machined, was prepared an environment of lighting to highlight areas of interest improving the luminance of the same and enabling the application of techniques developed in this prototype. Different operators for detecting edges were exploited in order to implement the best technical and that best represent the real piece. A new technique of targeting the prototype was adapted from the integration of technology Java / MatLab and with the acquisition of images through technical Multi-flash. After the application of different processing techniques, a text file containing the coordinates of the image (piece) is generated and imported into CAD. In the CAD environment, runs calculating the trajectory of the tool that identifies the geometry of the piece and defines the path of the tool in the generation of CNC program for breeding the same. Results presented and evaluation of the tool demonstrates the feasibility of applying the automated system developed as part of parts to play in numerical control machines. / O presente trabalho descreve uma ferramenta para extração de características em imagens 2D aplicado à automação industrial. O método implementado utiliza técnicas de segmentação de imagens em peças modelo, como detecção de bordas, na extração das coordenadas espaciais da imagem e importação em aplicativos CAD (Computer-Aided Design) para a geração de programas de Comando Numérico Computadorizado (CNC). Este trabalho consiste em copiar um determinado modelo (imagem) partindo de um objeto já existente, o que caracteriza um processo de engenharia reversa. Um protótipo inicial foi desenvolvido usando a linguagem Java com o IDE Eclipse e a biblioteca para manipulação de imagens complexas, o API Java Advanced Image (JAI). Para a aquisição das peças a serem usinadas, foi elaborado um ambiente de iluminação a fim de ressaltar áreas de interesse melhorando a luminância das mesmas e viabilizando a aplicação das técnicas desenvolvidas nesse protótipo. Diferentes operadores de detecção de bordas foram explorados, a fim de aplicar a melhor técnica e que melhor representasse a peça real. Uma nova técnica de segmentação foi adaptada ao protótipo, a partir da integração da tecnologia Java/MatLab e com a aquisição de imagens através da técnica Multi-flash. Após a aplicação de diferentes técnicas de processamento, um arquivo texto contendo as coordenadas da imagem (peça) é gerado e importado no CAD. No ambiente CAD, é executado o cálculo da trajetória da ferramenta que identifica a geometria da peça e define o caminho da ferramenta na geração do programa CNC para reprodução da mesma. Resultados apresentados e a avaliação da ferramenta demonstram a viabilidade de aplicação do sistema desenvolvido como parte automatizada para reprodução de peças em máquinas de comando numérico.
186

Inovace výroby CNC obrábění diskovitých součástí / An innovation of the CNC production of the disc-shaped parts

Křupka, Marek January 2013 (has links)
The optimal choice of cutting conditions, as well cutting tool, has a significant effect on the quality of machined part and is an essential parameter to reduce the cost of production. This thesis describes CNC turning process of disc springs made of 51CrV4 material, especially using new cutting tools and the use of higher cutting speeds. A comparison of four manufacturers of cutting tools in terms of surface quality, tool path and the machined material volume will be introduced. It was experimentally verified that our proposed facility has achieved the best result.
187

Projeto e implementação de um controlador numérico computadorizado aberto baseado em STEP-NC

Pacheco, Nazareno de Oliveira 18 February 2009 (has links)
Made available in DSpace on 2016-12-12T17:38:36Z (GMT). No. of bitstreams: 1 Nazareno.pdf: 5066639 bytes, checksum: d126b9cbc310906e85db744b2286d806 (MD5) Previous issue date: 2009-02-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No trabalho desenvolvido foi utilizada a Norma ISO 14649 (STEP-NC) que é o novo pa¬rão para interface de dados de manufatura entre os sistemas CAM/CNC. Atualmente a oca dessas informações é feita usando a linguagem da Norma 1S06983, conhecida como ódigo-G/M. Isto significa que partes das informações geradas no ciclo de Desenvolvimento, notadamente a geometria do produto e dados de ferramentas, são perdidas ao se gerar o programa em codigo G/M Para a prova de conceito da funcionalidade desse novo padrão no controle e acionamento direto de maqumas ferramenta CNC foram projetados construidos software, hardware e uma estrutura mecânica simples de uma fresadora/¬:radeira CNC. A arquitetura de software e hardware é aberta e aderente à STEP-NC. sistema desenvolvido faz uso de arquivos ISO14649 para programação da maquina sem o de linguagens legadas Isto permitiu a validação do uso da norma no acionamento de quinas CNC, provando a flexibilidade e eficacia para a troca de informações e controle maquinas-ferramenta.
188

A model for analysis and design of an integrated operations management system using systems engineering approach: A case study / En modell för analys och design av ett system för integrerad verksamhets-styrning med hjälp av systems engineering: En fallstudie

Thalji, Idriss, Zubair, Gaith January 2007 (has links)
Background: Generally, operation management includes a set of complicated systems interfacing each other. Most important systems which impact and impacted by the operations management system are production management system and maintenance management system. But to treat the interfacing losses has been difficult as interact and partially overlap each other. In this study, case-operational system was treated with developed model that analysis and design integrated operational system in order to make it easier and cost effective to manage. Methods: A model was developed based on latest literature survey work using systems paradigm methodology and systems engineering approach. Results: Among five analysis techniques, four types of interfacing losses were identified, seven requirements were extracted, nine conceptual solutions were generated, one of them was selected and based on it the integrated operational management system were designed. Conclusions: The results suggest that the operational system in case-company shall be integrated by organization management, process management, and control management, in addition to data management. / Bakgrund: I allmänhet har operations verksamhet en del komplicerade system där friktion kan förekomma. De viktigaste systemen som har påverkan på operations verksamhet är produktion och underhålls system. Att behandla friktions förluster har varit svårt eftersom de både samverkar och delvis överlappar varandra. I dem här studien har olika fall av operationssystem behandlats med att först utveckla en modell, analysera och designa den integrerade operationssystemet för att få den billigaste och dem mest kostnads effektiva sätt att klara av. Metod: En modell har utvecklats baserat på de senaste metoderna genom att använda system paradigm metoder och systemtekniska angreppssätt. Resultat: Genom att använda fem sätt att analysera, sju bestämmelser extraherade, nio lösningar generade, valdes en av lösningarna och med lösningen som grund designades operations verksamhet. Slutsats: Resultatet förslog att operations verksamhet skall integrera organisation, process och kontroll ledningar och inte bara data ledningen.
189

Desenvolvimento de apalpador de contato elétrico (\"touch trigger probe\") para atuação no processo de torneamento / Devefopment of a low cost touch trigger probe for CNC lathes

Marcelo Del Guerra 21 September 2004 (has links)
A utilização dos apalpadores acoplados a máquinas CNC se tornou uma realidade muito comum no mundo atual, principalmente devido à diminuição do tempo de preparação e possibilidades de realização de medições na própria máquina-ferramenta. Porém, ainda existem algumas barreiras a se transpor, como por exemplo, a dificuldade de programação, custo relativamente elevado e pouca literatura que trata exclusivamente a respeito da utilização dos apalpadores para medição nas máquinas-ferramentas. Nesse trabalho é realizada uma revisão bibliográfica sobre o uso dos apalpadores em ambiente industrial, discutindo-se as tecnologias utilizadas na geração do sinal de \"trigger\" e é proposto um novo modelo de apalpador de contato elétrico, de baixo custo, desenvolvido especialmente para atender as necessidades de medições em tornos CNC. Os testes em laboratório revelaram que a repetibilidade do protótipo construído foi de 0,003 mm dentro de uma confiabilidade de mais ou menos 3 \'sigma\' ou 99,73%. Concluiu-se que tais características são altamente compatíveis com os requisitos necessários para a maioria dos processos de torneamento. / The use of touch trigger probes attached to CNC machines has become a world standard, especially due the reduction of setup time and the ability to promote work piece measurements on machine. However, some barriers like measurement routines programming difficulties, high costs of these equipments and the low number of technical literature about this subject, still need to be transposed. This work presents a review on the applications of touch trigger probes on companies shop floor, discussing the nowadays technologies used to generate the trigger signal. A new touch trigger probe model based on a simple electrical contact is specially developed to provide the measuring characteristics required for Lathes, with the needed characteristics and low cost. The tests of the probe developed in the laboratory shown a repeatability of 0,003 mm (more and less 3 \'sigma\' or 99,73%). Those characteristics are high compatible with the most needs of the industry.
190

Konstrukční návrh portálové CNC frézky s posuvným stolem / Design of the gantry CNC milling machine with sliding table

Kolář, David January 2017 (has links)
This master’s thesis is focused on design of gantry CNC milling machine with sliding table. Thesis includes the review of components of this machines and comparsion of their options. Servo motors , ball screws and linear guides parameters are calculated. Also the suitable software and hardware for the machine control is chosen. Main parts of the machine were analysed using finite elements method. 3D model, drawings and documentation of machine build are included.

Page generated in 0.0961 seconds