• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 15
  • 4
  • 4
  • 3
  • 1
  • Tagged with
  • 28
  • 8
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

Modeling of distributed layouts for dynamic period cases

Ganesan, Admanathan 12 1900 (has links)
In this work, a systematic methodology to construct distributed layouts has been developed. Previous researches in this field suggest distributed layouts as an alternative to process layouts. But there has been no systematic methodology so far to develop distributed layouts. Earlier works concentrate on evaluating different production schedules for randomly distributed resources throughout the plant floor. As opposed to former approaches, in this work, distributed layouts are developed based on actual production and routing data. Taking into account the exact capacity requirements of machines, a methodical approach to distribute resources rather than random assignment is considered. The need for developing process layouts is analyzed and justified using product similarity and cell utilization. Process layouts are developed only when the given production data meets process layout requirements. The efficiency of proposed approach relative to traditional process layout strategy has been evaluated in terms of material handling cost for both single and multi period settings. In a multi period setting, the impact of demand disturbances on both process and distributed layouts is studied using case studies. From the case study results, it is concluded that distributed layouts constructed using proposed approach performs exceedingly well over traditional process layout approach. Distributed layouts proved to be efficient and robust for both single and multi-period cases. Even huge fluctuations in demand level of products had only little impact on distributed layouts whereas process layouts suffered tremendous loss in terms of material handling cost. It turned out that for all cases, the improvement in efficiency of distributed layouts was more than 30% over process layouts. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Industrial and Manufacturing Engineering.
2

HYBRID FLOW STRATEGIES FOR HIGH VARIETY LOW VOLUME MANUFACTURING FACILITIES TO IMPLEMENT FLOW AND PULL

Narayanan, Mukund 01 January 2002 (has links)
Lean Manufacturing has proven to be a very successful strategy for achieving production efficiencies. The basic elements of lean manufacturing are flow and pull. The traditional methods for establishing flow and pull do not fit well in the realm of high variety low volume manufacturing systems. This thesis provides a general framework for establishing flow and pull in high variety low volume manufacturing systems, through the concept of hybrid flow layouts. The existing analytical procedure for forming hybrid flow layouts is described and a new heuristic procedure, that overcomes some of the limitations of the existing procedure, is proposed. The performance of the new procedure in comparison to the existing procedure is illustrated using a real world case study. Finally, certain practical implementation issues that affect the formation of hybrid flow layouts are provided.
3

Förslag för effektivare materialförsörjning i monteringen utifrån Leanprinciper

Kähr, Gerli January 2016 (has links)
Syfte – Syfte med detta arbete är att undersöka vilka materialförsörjningsprinciper i en monteringshall kan ge ett effektivare och säkrare arbetssätt samt minskad resursåtgång. För att kunna besvara syftet har det brutits ned till två problemfrågor: 1. Vilka materialförsörjningsprinciper vid monteringsverksamhet skulle kunna effektivisera monteringen? 2. Hur stora är besparingarna för de föreslagna materialförsörjningsprinciperna? Metod – För att uppfylla studiens syfte utfördes en fallstudie på Proton Lighting AB i Värnamo. Med hjälp av intervjuer, observationer och dokumentstudier samlades in empirisk data, som har analyserats och tolkats gentemot teori, som samlades in via litteraturstudie. Analys av data har genererat studiens resultat. Resultat – Materialförsörjningsprinciper som föreslås till en monteringshall är kittning, kontinuerligt försörjning, batchning och supermarket ihop med dragtruck som resulterar minskning av personalbehov vilket beräknades att spara upp till 27 000 kr/vecka. Föreslagna materialförsörjningsprinciperna tillför behov till layoutförändringar. Förslag är att skaffa FIFU-banor, kanbansystem och dragtruck så att ett effektivt arbetssätt och materialhanteringsprocess kan uppnås. Att föra ihop två monteringshallar ger företaget en tom golvyta så att den gemensamma hallen kan används på ett optimalt sätt, materialförsörjning sker i en monteringshall och anställda känner gemenskap. Genom att skapa mellanlager minskas trucktransporterna i arbetsområdet, samt att de sparar tid då den långa transportsträckan och inplastningen av pallar försvinner. Implikationer – Inom denna studie framgår det att besparingar kan uppnås i en monteringshall med de föreslagna materialförsörjningsprinciperna som utgår från Lean-principer. Begränsningar – Det finns inte så många specifika artiklar eller många andra som skriver om materialförsörjningsprinciper i en monteringshall då lyfts värde av denna rapport. Under studie visade sig att tiden inte räckte till för att utföra undersökningar gällande provstationer därmed bestämdes det att utelämna utmaningar över provstationer i denna studie. Nyckelord – Logistik, materialförsörjning, materialhantering, Lean Production / Purpose – Purpose of this work is to examine which material supply policies in an assembly can provide a more efficient and safer working and reduced resource consumption. In order to answer the purpose, it has been broken down to the two following questions: Which material supply policies in the assembly could make more efficiency of the assembly? How large are the savings of the proposed material supply principles? Method – To fulfill the purpose of the study, a case study was performed at Proton Lighting AB in Värnamo. With the help of interviews, observations and document studies, empirical data was collected wich has been analyzed and interpreted against the theory which was collected through literature. Analysis of the data has been generated to the study’s result. Findings – Material supply principles which is proposed in an assembly is kitting, continuous supply, batching and supermarket together with the tow truck which would result reduction of personnel which was calculated to save up to 27 000 SEK/week. Suggested materials supply principles bring needs to layout changes. The proposal is to get FIFO-racks, kanban systems and towing trucks so that effective methods and materials handling process can be achieved. Bringing together two assembly halls gives the company an empty hall and the other hall can be used at maximum way, material supply occurs in one assembly hall and employees feel community. By creating the inventory reduces truck transportation in the work area and saves time when the long transportation distance and pallets wrapping disappear. Implications – In this study, it appears that with one assembly hall, savings can be achieved with the proposed material supply principles based on Lean principles. Limitations – There are not many specific articles or many others that write about material supply policies in an assembly hall which lifts the value of this report. The study showed that the time was not enough to carry out studies on the test stations thus it was decided to omit the challenge of test stations in this study. Keywords – Logistics, supply chain, materials management, Lean Production
4

A tool for comparing costs of conveyor network layouts

Aliwarga, Ivan Sutopo January 2001 (has links)
No description available.
5

Conceptual Optimization of amultistage production facility : A study on the current production facility

Dubey, Arnav, Nambiar, Vighnesh January 2023 (has links)
This study contains suggestions for the question “How might the future production setup at Permobil look like?”. The idea is to provide solutions based on inputs from the current knowledge boundariesand practices of the production team. The work aims at gathering data from the current practices within the firm, identify the wastes, needs, and potential improvements and conducting studies on state-ofthe-art Industrial practices, trends, and upcoming future technologies in production. Value stream mapping is done to help better understand the current state across the production facility and hence plan for future production setup. The solutions on strategies for key areas, namely, warehousing, production line, material handling, quality control and overall integrated production setup are derived from first benchmarking against Industrial practices and then deriving options for the flow of resourcesand information across the Production value chain. The study suggests in-detail ideas of what all production trends can be incorporated for the new upcoming production setup in the future and is in tight accordance with Permobil’s lean principles.With the findings from Value Stream Mapping, we made suggestions for new layouts for the newfactory, and we ranked these suggestions based on an evaluation model. Automation in material handling, setup of the assembly line, changes in current customization setup and use of technology in many ways to aid in the operations are identified as the important transitions for future setup. Finally using the results from the layout suggestions, we performed a warehouse simulation between the suggested layout and the current layout based on distance travelled and parts delivered to line.Concluding this study by connecting the findings from VSM, Layout suggestions and Warehousesimulation. / Denna studie innehåller förslag på frågan ”Hur kan den framtida produktionsupplägget hos Permobilse ut?”. Tanken är att tillhandahålla lösningar baserade på input från produktionsteamets nuvarande kunskapsgränser och praxis. Arbetet syftar till att samla in data från nuvarande praxis inom företaget, identifiera avfall, behov och potentiella förbättringar och genomföra studier om toppmoderna industriella tekniker, trender och kommande framtida teknologier i produktionen. Värdeströmskartläggning görs för att bättre förstå det nuvarande tillståndet i produktionsanläggningenoch därmed planera för framtida produktionsupplägg. Lösningarna för strategier för kritiska områden, nämligen lagerhållning, produktionslinje, materialhantering, kvalitetskontroll och övergripande integrerad produktionsuppsättning härrör från först benchmarking mot industriell praxis och sedan härledande av alternativ för flödet av resurser och information över hela produktionsvärdekedjan. Studien föreslår detaljerade idéer om vad alla produktionstrender kan införlivas för den nya kommande produktionsuppsättningen i framtiden och är i strikt överensstämmelse med Permobils lean-principer. Med resultaten från Value Stream Mapping gav vi förslag på nya layouter för den nya fabriken, och vi rangordnade dessa förslag utifrån en utvärderingsmodell. Automatisering i materialhantering,uppsättning av löpande band, förändringar i nuvarande anpassningsupplägg och användning av teknik på många sätt för att underlätta verksamheten identifieras som viktiga övergångar för framtidainstallationer. Slutligen med hjälp av resultaten från layoutförslagen genomförde vi en lagersimulering mellan den föreslagna layouten och den aktuella layouten baserat på tillryggalagd sträcka och delar levererade till linjen. Avsluta denna studie genom att koppla samman resultaten från VSM, layoutförslag och lagersimulering.
6

Produktionslayouter under den fjärde industriella revolutionen : En studie som jämför lina med funktionell layout under dagens marknadsförhållanden och teknologiska lösningar / Facility layouts during the Fourth Industrial Revolution : A study that compares line with functional layout during today's market conditions and technological solutions

Stabnikov, Valentin January 2023 (has links)
Dagens marknad är mycket osäker och föränderlig, vilket är en utmaning för bland annat industriföretag. För att förbli relevanta för marknaden måste företag anpassa sig. Anpassningen möjliggörs genom att företagen är flexibla i hela sin verksamhet. För ett industriföretag kan flexibilitet avse produktionsflexibilitet i produktionslayouter. Det är en mycket viktig komponent för att kunna hantera korta produktlivscykler och snabbt utvecklanya produkter. Denna kandidatuppsats undersöker vilken layout av de centrala layouterna, linan eller funktionella layouten, som är mest fördelaktig vad gäller flexibilitet och produktionskostnader givet nya lösningar från Industri 4.0. För att svara på frågan genomfördes en analys och en litteraturstudie baserade på ett studiebesök på Volvo fabriken i Köping. Analysen genomfördes genom att konstruera en lina som sedan skulle jämföras med en yteffektiviserad funktionell layout från Volvo fabriken i Köping. Resultaten av analysen visade att en lina med en rads placering har minst area men är lägre expansionsflexibel än en funktionell layout med Industri 4.0-lösningar. / Today's market is very uncertain and changing, which is a challenge for, among other things, industrial companies. To remain relevant in the market, companies must adapt. Adaptation is made possible by the companies being flexible throughout their operations. For an industrial company, flexibility can refer to production flexibility in production layouts. It is a very important component to be able to manage short product life cycles and quickly develop new products. This bachelor's thesis examines which production layout of the main layouts, a product or a functional layout, is most beneficial in terms of flexibility and production costs given new solutions from Industry 4.0. To answer the question, an analysis and a literature study were carried out based on a study visit to the Volvo factory in Köping. The analysis was carried out by constructing a product layout which would then be compared with a surface-efficient functional layout from the Volvo factory in Köping. The results of the analysis showed that a product layout with single-row placement has the least footprint but is less expansion flexible than a functional layout with Industry 4.0 solutions.
7

MagnetViz : design and evaluation of a physics-based interaction technique for graph visualization / MagnetViz : projeto e avaliação de uma técnica de interação baseada em física para visualização de grafos

Spritzer, Andre Suslik January 2009 (has links)
Esta dissertação apresenta MagnetViz, uma técnica para visualização de grafos. Enquanto a maior parte das técnicas visualizam um layout de grafo estático pre-computado, MagnetViz permite que usuários dinamicamente alterem o layout de um grafo de forma a melhor satisfazer suas necessidades. Isso é feito ao construir em cima da metáfora de física de algoritmos dirigidos à força para proporcionar aos usuários imãs virtuais, que podem atrair nodos que satisfazem um conjunto de critérios associados a eles. Critérios podem ser baseados na topologia ou semântica do grafo. Através de boundary shapes, que são simples formas geométricas que podem ser colocadas ao redor de imãs, usuários podem também definir regiões na cena onde os nodos atraídos devem permanecer. Grafos são descritos usando GraphML, uma linguagem baseada em XML, que permite a especificação dos nodos e arestas e de atributos para essas entidades. Após a submissão de um grafo como entrada, MagnetViz o exibe utilizando uma versão modificada do algoritmo clássico de Fruchterman and Rheingold, e permite que usuário, a seguir, insira imãs na cena. Usuários podem construir as condições associadas aos imãs utilizando os atributos dos nodos e arestas, além de atributos topológicos próprios de grafos. Para a avaliação de MagnetViz, foi primeiro analisado o desempenho da técnica ao ajudar usuários a executarem tarefas definidas por uma taxonomia de tarefas de visualização de grafos encontrada na literatura. Então, MagnetViz foi testada em um contexto prático através de um estudo de caso. Uma rede de co-autorias foi escolhida como conjunto de dados e o protótipo de MagnetViz foi inicialmente usado para responder questões relevantes a esses dados e então testado por um grupo de potenciais usuários, que tinham de usa-lo para responder essas mesmas perguntas. Após testar a aplicação, os sujeiotos receberam questionários sobre usas opiniões quanto a usabilidade, aplicabilidade, relevância e resultados visuais da técnica. Enquanto alguns aspectos da técnica ainda podem ser melhorados, os resultados da avaliação provaram que MagnetViz é uma abordagem válida para interação com visualizações de grafos. / This dissertation presents MagnetViz, a technique for the visualization of graphs. While most techniques visualize a static pre-computed graph layout, MagnetViz allows users to dynamically alter the layout of a graph to better satisfy their needs. This is done by building on the physics metaphor of force-directed algorithms to provide users with virtual magnets, which can attract nodes that fulfill a set of criteria associated with them. Criteria can be based on either the topology or semantics of the graph. Through boundary shapes, which are simple geometric shapes that can be placed around magnets, users can also define regions within the scene where the attracted nodes should remain. Graphs are described in GraphML, a XML-like description language which allows the specification of nodes and edges between nodes as well as attributes associated to nodes and edges. After loading a graph, Magnetviz displays it using a slightly modified version of the classical Fruchterman and Reingold' algorithm, and allows the user to insert magnets. Users can build the criteria associated with the magnets using the attributes of nodes and/or edges, besides the common graphs' topological attributes. For MagnetViz's evaluation, it was first analyzed how the technique fared in aiding users to perform tasks defined by a graph visualization task taxonomy described in the literature. Then, MagnetViz was tested within a practical context by means of a case study. A co-authorship network was chosen as the target dataset. The MagnetViz prototype was initially used to answer questions relevant to this dataset and then tested by a group of potential users, who had to use it to answer these same questions. After trying the application, subjects answered questionnaires about their opinion on the technique's usability, applicability, relevance and visual results. While some aspects of the technique should still be refined, results of the evaluation proved MagnetViz to be a valid approach when it comes to interaction with graph visualizations.
8

MagnetViz : design and evaluation of a physics-based interaction technique for graph visualization / MagnetViz : projeto e avaliação de uma técnica de interação baseada em física para visualização de grafos

Spritzer, Andre Suslik January 2009 (has links)
Esta dissertação apresenta MagnetViz, uma técnica para visualização de grafos. Enquanto a maior parte das técnicas visualizam um layout de grafo estático pre-computado, MagnetViz permite que usuários dinamicamente alterem o layout de um grafo de forma a melhor satisfazer suas necessidades. Isso é feito ao construir em cima da metáfora de física de algoritmos dirigidos à força para proporcionar aos usuários imãs virtuais, que podem atrair nodos que satisfazem um conjunto de critérios associados a eles. Critérios podem ser baseados na topologia ou semântica do grafo. Através de boundary shapes, que são simples formas geométricas que podem ser colocadas ao redor de imãs, usuários podem também definir regiões na cena onde os nodos atraídos devem permanecer. Grafos são descritos usando GraphML, uma linguagem baseada em XML, que permite a especificação dos nodos e arestas e de atributos para essas entidades. Após a submissão de um grafo como entrada, MagnetViz o exibe utilizando uma versão modificada do algoritmo clássico de Fruchterman and Rheingold, e permite que usuário, a seguir, insira imãs na cena. Usuários podem construir as condições associadas aos imãs utilizando os atributos dos nodos e arestas, além de atributos topológicos próprios de grafos. Para a avaliação de MagnetViz, foi primeiro analisado o desempenho da técnica ao ajudar usuários a executarem tarefas definidas por uma taxonomia de tarefas de visualização de grafos encontrada na literatura. Então, MagnetViz foi testada em um contexto prático através de um estudo de caso. Uma rede de co-autorias foi escolhida como conjunto de dados e o protótipo de MagnetViz foi inicialmente usado para responder questões relevantes a esses dados e então testado por um grupo de potenciais usuários, que tinham de usa-lo para responder essas mesmas perguntas. Após testar a aplicação, os sujeiotos receberam questionários sobre usas opiniões quanto a usabilidade, aplicabilidade, relevância e resultados visuais da técnica. Enquanto alguns aspectos da técnica ainda podem ser melhorados, os resultados da avaliação provaram que MagnetViz é uma abordagem válida para interação com visualizações de grafos. / This dissertation presents MagnetViz, a technique for the visualization of graphs. While most techniques visualize a static pre-computed graph layout, MagnetViz allows users to dynamically alter the layout of a graph to better satisfy their needs. This is done by building on the physics metaphor of force-directed algorithms to provide users with virtual magnets, which can attract nodes that fulfill a set of criteria associated with them. Criteria can be based on either the topology or semantics of the graph. Through boundary shapes, which are simple geometric shapes that can be placed around magnets, users can also define regions within the scene where the attracted nodes should remain. Graphs are described in GraphML, a XML-like description language which allows the specification of nodes and edges between nodes as well as attributes associated to nodes and edges. After loading a graph, Magnetviz displays it using a slightly modified version of the classical Fruchterman and Reingold' algorithm, and allows the user to insert magnets. Users can build the criteria associated with the magnets using the attributes of nodes and/or edges, besides the common graphs' topological attributes. For MagnetViz's evaluation, it was first analyzed how the technique fared in aiding users to perform tasks defined by a graph visualization task taxonomy described in the literature. Then, MagnetViz was tested within a practical context by means of a case study. A co-authorship network was chosen as the target dataset. The MagnetViz prototype was initially used to answer questions relevant to this dataset and then tested by a group of potential users, who had to use it to answer these same questions. After trying the application, subjects answered questionnaires about their opinion on the technique's usability, applicability, relevance and visual results. While some aspects of the technique should still be refined, results of the evaluation proved MagnetViz to be a valid approach when it comes to interaction with graph visualizations.
9

Uma avalia??o comparativa de estrat?gias de arranjos f?sicos para estaleiros de constru??o de embarca??es met?licas de pequeno porte

Sales, Rafael Ara?jo 25 August 2012 (has links)
Made available in DSpace on 2014-12-17T14:53:06Z (GMT). No. of bitstreams: 1 RafaelAS_DISSERT.pdf: 5777959 bytes, checksum: 98f8369474ac7e8d60ee3cf297989cd6 (MD5) Previous issue date: 2012-08-25 / The present study aims to analyse, in different levels of demand, what is the best layout strategy to adopt for the small metallic shipbuilding. To achieve this purpose, three simulation models are developed for analyze these production strategies under the positional, cellular and linear layouts. By the use of a simulation tool for compare the scenarios, Chwif and Medina (2010) and Law (2009)?s methodologies were adapted that includes three phases: conception, implementation and analysis. In conception real systems were represented by process mapping according to time, material resources and human resources variables required for each step of the production process. All of this information has been transformed in the cost variable. Data were collected from three different production systems, two located in Natal RN with cellular and positional layouts and one located in Bel?m-PA with linear layout. In the implementation phase, the conceptual models were converted in computacional models through the tool Rockwell Software Arena ? 13.5 and then validated. In the analysis stage the production of 960 ships in a year vessels were simulated for each layout noting that, for a production of until 80 units positional layout is the most recommended, between 81 and 288 units the cellular layout and more than 289 units the linear layout / O presente estudo tem como objetivo geral analisar, em diferentes n?veis de demanda, qual a melhor estrat?gia de arranjo f?sico adotar para a constru??o de embarca??es met?licas de pequeno porte. Para atingir o objetivo proposto, s?o desenvolvidos tr?s modelos de simula??o para analisar as estrat?gias de produ??o sob os arranjos f?sicos posicional, celular e linear. Por utilizar a ferramenta da simula??o para a compara??o de cen?rios, foi utilizada uma adapta??o das metodologias de Chwif e Medina (2010) e Law (2009) que contempla tr?s fases: concep??o, implementa??o e an?lise. Na concep??o os sistemas reais foram representados atrav?s do mapeamento dos processos de acordo com as vari?veis tempo, recursos materiais e recursos humanos necess?rios para cada etapa do processo produtivo. Todas essas informa??es foram transformadas na vari?vel custo. Os dados foram coletados em 3 sistemas de produ??o de lanchas do tipo escolar distintos, dois localizados em Natal-RN com produ??o posicional e celular e um localizado em Bel?m-PA com produ??o linear. Na fase de implementa??o os modelos conceituais foram convertidos em modelos computacionais atrav?s da ferramenta Rockwell Software Arena? 13.5 e em seguida validados. Na etapa de an?lise simulou-se a produ??o anual de 960 embarca??es para cada arranjo f?sico constatando-se que, para uma fabrica??o de at? 80 unidades o arranjo f?sico mais recomendado ? o posicional, entre 81 e 288 unidades o arranjo celular e de 289 unidades em diante o arranjo linear
10

The Perception of Graph Properties In Graph Layouts

January 2018 (has links)
abstract: When looking at drawings of graphs, questions about graph density, community structures, local clustering and other graph properties may be of critical importance for analysis. While graph layout algorithms have focused on minimizing edge crossing, symmetry, and other such layout properties, there is not much known about how these algorithms relate to a user’s ability to perceive graph properties for a given graph layout. This study applies previously established methodologies for perceptual analysis to identify which graph drawing layout will help the user best perceive a particular graph property. A large scale (n = 588) crowdsourced experiment is conducted to investigate whether the perception of two graph properties (graph density and average local clustering coefficient) can be modeled using Weber’s law. Three graph layout algorithms from three representative classes (Force Directed - FD, Circular, and Multi-Dimensional Scaling - MDS) are studied, and the results of this experiment establish the precision of judgment for these graph layouts and properties. The findings demonstrate that the perception of graph density can be modeled with Weber’s law. Furthermore, the perception of the average clustering coefficient can be modeled as an inverse of Weber’s law, and the MDS layout showed a significantly different precision of judgment than the FD layout. / Dissertation/Thesis / Masters Thesis Computer Science 2018

Page generated in 0.0207 seconds