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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.
141

Den svenska aktiemarknadens beroende av makroekonomin i Tyskland och USA / The Swedish Stock Market's Dependence of the Macroeconomy in Germany and USA

Karlsson, Robin, Olsson, Jessica January 2007 (has links)
Bakgrund: Dagligen diskuteras utländsk makroekonomiska data i svensk media, där förväntningarna på utvecklingen av dessa sätts i sammanhang med utvecklingen på den svenska börsen. Syfte: Målet med den här studien var att utröna i hur stor utsträckning denna information kan anses vara betydande för en aktieinvesterare med kapital på den svenska börsen. Hänsyn togs även till börscykler samt varierande tidsperioder. Genomförande: Med grund i the Arbitrage Pricing Theory genomfördes multipla regressionsanalyser, med det svenska indexet OMXS30 som beroendevariabel. Undersökningarna baserades på månadsdata för perioden april 1991 till och med augusti 2006. Den makroekonomiska datan försköts därtill en period för att ta hänsyn till variablernas eventuella fördröja effekter på Stockholmsbörsen. Resultat: Integrationen mellan börserna visade sig ha ökat över tiden, med undantag för extraordinära perioder som IT-boomen, där makroekonomiska fundamentaldata istället slås ut. En positiv utvecklingen av långräntan samt konsumentförtroendet i USA tyder på en samtida börsuppgång i Sverige. Vidare är båda växelkurserna starkt signifikanta, där en stärkt dollar och en försvagad euro har positiva effekter på den svenska marknadsutvecklingen. / Background: Foreign macroeconomic fundamentals are daily discussed in the Swedish media, where expectations on the development of these are put into context with the ecnonomic development in Sweden. Aim: The purpose of this thesis is to analyse to what extent this information is important for a investor on the Swedish Stock Market. Consideration was also taken to trends in the Stock Market as well as varying time periods. Research Method: Against the background of the Abritrage Pricing Theory a multiple regression analysis was conducted,with the Swedish Stock Market Index OMXS30 as the dependent variable. The macroeconomic variables where based on monthly data between April 1991 and August 2006 and were thereto lagged one period in order to identify any delayed effects. Result: The integration between the Stock Markets was found to increse over time, with the exception of extraordinary periods, as the IT-boom, where macroeconomic fundamentals lost significance. A positive long-term interest rate as well as a positive consumer confidence in the U.S. was found to indicate a contemporary rising market in Sweden. Further were both of the exchange rates found significant, where a stronger dollar and a weaker euro have positive effects on the Swedish current Stock Market.
142

影響都市更新合建分配比率因素之研究-以台北市為例 / Factors affecting share distribution in jointly developed urban renewal projects --- an example of Taipei City

江志恩, Chiang, Chih En Unknown Date (has links)
過去都市更新相關文獻中,多在分析都市更新制度與探討相關法令缺失,且多以權利變換方式探討地主權益之分配,較少以量化分析來研究都市更新協議合建分配型態,對於地主所關注合建分配比率之影響因素也未能深入研究。本研究透過文獻回顧與台北市都市更新之現況分析後,掌握可能之影響變數,藉由實證資料之蒐集與相關變數之選取,將資料進行複迴歸實證分析,以探討影響都市更新合建分配比率之顯著變數。 本研究篩選出可能影響合建分配比率之14個自變項,並排除相關係較高之土地所有權人數及建築成本兩變數後,透過複迴歸分析,結果顯示有8項達顯著性之影響因素,其中個別屬性變數包括每人土地面積、每容積公告土地現值、平均容積率、臨路寬度與臨路寬度平方、都市更新容積獎勵率、區域房價等6項達顯著性,除臨路寬度平方與都市更新合建分配比率呈負向關係外,其他皆呈正向關係,而在總體經濟變數有上一月基準利率及上一季M2年增率等2項達顯著性,其中上一月基準利率與都市更新合建分配比率呈負向關係,而上一季M2年增率與都市更新合建分配比率呈正向關係。 由實證結果得知,增加都市更新容積獎勵,確實有助提昇地主合建分配比率,因此,政府應適度調整容積獎勵項目及上限,使地主參加都市更新後,能獲得較佳之居住環境與較高之居住面積水準,甚至保障地主原居住面積水準,以增加地主參與都市更新之意願。期望政府持續大力推動都市更新政策,透過建築規劃及設計,達到改善市容、美化環境、增進公共安全及提昇居住水準等政策目的,進而達到政府、地主及開發商三贏之目標。 / Most of the past research studies on urban renewal involves analysis in the related regulations and their shortcomings. Furthermore, studies based on allocation of land owners’ equity rights are mostly done from perspective of the rules set from the government supervised appraisal process known as Rights Transformation. Few of them are conducted using the quantitative approach to derive the equity rights of the landowners from the perspective of the process known as Joint Development --- a process of private negotiation and derived terms. Thus, through analysing research articles and the current state of the urban renewal projects in Taipei, this study first intends to identify the possible variables that might affect the equity share distribution. Then using regression analysis based on the selected variables and collections of empirical data, this study explores and derives variables of significant impacts on the equity share distribution between developers and landowners in jointly developed urban renewal projects. This research has screened 14 independent variables that might have impact the equity share distribution. Results of regression analysis identify 8 significant factors, including land area per owner, government assesed land value per floor area, average floor area ratio, road width, square of road width, floor area incentive for urban renewal, and surrounding area housing value. Most of the variables have positive relationships with the landowners’ equity except for the square of road width. Macroeconomic variables such as last month’s prime interest rate and M2 growth rate in the previous quarter are found to have significant impact as well. Of which, prime interest rate is found to have negative relationship with landowners’ equity, and M2 growth rate is found to have positive relationship. Based on this empirical study, the result shows that increasing urban renewal floor area incentives indeed enhances landowners’ equity rights in a jointly developed urban renewal project. Thus, government should adjust appropriately each of the floor area incentives and their maximum allowed limits, giving the original residents a better living environment and a slightly larger living space from the redeveloped project. Furthermore, to increase the willingness of the original residents’ participation in urban renewal projects, the government could guarantee the retention of their floor area in the redeveloped projects to be the same as the floor area before urban renewal. The government should continue to promote its urban renewal policy. Proper architecture planning and design will improve the city’s appearance and the environment, as well as enhancing public safety and living standards - through which the government will not only achieve its policy objectives, but also create a win-win situation between the developers, landowners, and the government itself.
143

Modelling mechanical properties by analysing datasets of commercial alloys

Zander, Johan January 2007 (has links)
<p>Commercial alloys are continuously developed to improve their performance. Therefore it is important to develop new optimisation software, which could be used in development of new materials or in materials selection. In this study the mechanical properties which are important in materials selection in mechanical design are investigated. Two types of materials are analysed, aluminium alloys and stainless steels but focus will be on the aluminium alloys.</p><p>Thermodynamic analysis has been used to evaluate the effect of the microstructure. Solid solution hardening has been successfully modelled for both aluminium alloys and stainless steels and follows the theories by Labusch and Nabarro. The precipitation hardening is most dominant for the hardenable aluminium alloys, but the non-hardenable alloys also increase their strength from precipitation hardening. The non-hardenable alloys are divided into tempers, which differ in the amount of strain hardening. This has also been modelled successfully.</p><p>Combining these fundamental results with multiple regression, models for mechanical properties have been created. Separate models are developed for wrought aluminium alloys and stainless steels. For the aluminium alloys this includes the solid solution hardening and the precipitation hardening. For the stainless steels the thickness, nitrogen content and ferrite content are included together with the solid solution hardening.</p>
144

Employee commitment and its impact on process quality in a manufacturing concern / Elsabè van Blerk.

Van Blerk, Elsabè Johanna January 2012 (has links)
The aim of this study was to evaluate employee commitment to achieve the primary objective, which was to evaluate employee commitment towards product and process quality. Employees who are engaged in their work and committed to their organisations give companies crucial competitive advantages – including higher productivity, better quality products and lower employee turnover. A thorough literature study was conducted by using the views of different authors and combining them. The concept of quality was defined by making use of the five quality gurus; Deming, Juran, Feigenbaum, Crosby and Ishikawa. The fourteen principles of quality, developed by Deming, were presented in Table 2.1. These principles had the goal of increased productivity, with less rework, less waste of manpower and material resources, resulting in a reduction of costs, to in turn give the organisation greater market share and ultimately better competitive position, by improving the overall quality of an organisation’s work processes. The concept of employee and organisational commitment was defined, and from this study it is evident that employee commitment towards the company is positive and therefore should have a positive effect on their operating environment. The product process flow for this manufacturing concern were discussed to give an overall view of the production processes used in this organisation. An empirical study was completed using a questionnaire survey to determine employee commitment at a manufacturing concern in Gauteng. The questionnaire used for this study was designed to focus on commitment towards internal quality only, to specifically evaluate employee perspective towards product quality, as well as the commitment towards the organisation. Analysis of the responses showed the questionnaire to be reliable and valid. Respondents indicated that they are committed towards the organisation in general across all constructs, but a lack in management trust was a predominant sentiment. The quantitative analysis showed that after a factor analysis was done on the two sections of the questionnaire, four factors for each section were considered as meaningful. These factors were: Affinity, quality awareness, autonomy and corporate image (employee commitment - section B) and employee commitment, task performance, job satisfaction and contextual performance (company relationship – section C). This indicated strong employee commitment towards the organisation. The qualitative results had four areas that all respondents felt needed some attention, and loaded negative towards the organisation. These were HR (trust in management, competency, communication and company culture), skills development, employee development and BBBEE. Thus, drawing conclusions from quantitative results alone could give a company a false sense of employee commitment towards the company and therefore overlook the importance of the roles that employees play in executing strategic plans. Conclusions regarding the findings of the research study were presented and recommendations for this organisation were made. These recommendations are merely a guideline that correlates directly to the empirical analysis made. The research study was evaluated against the primary and secondary objectives with the conclusion that both were achieved. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
145

Employee commitment and its impact on process quality in a manufacturing concern / Elsabè van Blerk.

Van Blerk, Elsabè Johanna January 2012 (has links)
The aim of this study was to evaluate employee commitment to achieve the primary objective, which was to evaluate employee commitment towards product and process quality. Employees who are engaged in their work and committed to their organisations give companies crucial competitive advantages – including higher productivity, better quality products and lower employee turnover. A thorough literature study was conducted by using the views of different authors and combining them. The concept of quality was defined by making use of the five quality gurus; Deming, Juran, Feigenbaum, Crosby and Ishikawa. The fourteen principles of quality, developed by Deming, were presented in Table 2.1. These principles had the goal of increased productivity, with less rework, less waste of manpower and material resources, resulting in a reduction of costs, to in turn give the organisation greater market share and ultimately better competitive position, by improving the overall quality of an organisation’s work processes. The concept of employee and organisational commitment was defined, and from this study it is evident that employee commitment towards the company is positive and therefore should have a positive effect on their operating environment. The product process flow for this manufacturing concern were discussed to give an overall view of the production processes used in this organisation. An empirical study was completed using a questionnaire survey to determine employee commitment at a manufacturing concern in Gauteng. The questionnaire used for this study was designed to focus on commitment towards internal quality only, to specifically evaluate employee perspective towards product quality, as well as the commitment towards the organisation. Analysis of the responses showed the questionnaire to be reliable and valid. Respondents indicated that they are committed towards the organisation in general across all constructs, but a lack in management trust was a predominant sentiment. The quantitative analysis showed that after a factor analysis was done on the two sections of the questionnaire, four factors for each section were considered as meaningful. These factors were: Affinity, quality awareness, autonomy and corporate image (employee commitment - section B) and employee commitment, task performance, job satisfaction and contextual performance (company relationship – section C). This indicated strong employee commitment towards the organisation. The qualitative results had four areas that all respondents felt needed some attention, and loaded negative towards the organisation. These were HR (trust in management, competency, communication and company culture), skills development, employee development and BBBEE. Thus, drawing conclusions from quantitative results alone could give a company a false sense of employee commitment towards the company and therefore overlook the importance of the roles that employees play in executing strategic plans. Conclusions regarding the findings of the research study were presented and recommendations for this organisation were made. These recommendations are merely a guideline that correlates directly to the empirical analysis made. The research study was evaluated against the primary and secondary objectives with the conclusion that both were achieved. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
146

員工認股選擇權租稅政策對電子業股價之影響

張宗豪, Chang, Zong-Hao Unknown Date (has links)
本研究主要目標在探討有關員工認股選擇權租稅政策訊息之發布,是否對國內發行員工認股權憑證之上市及上櫃公司— 資訊電子業的股票報酬造成異常影響。在五個事件期間中,以第一、二及第五個事件期(即員工認股選擇權初步比照員工分紅入股依面額課徵所得稅、財政部初步擬定員工執行認股權時,須以執行價與當初認購價格間的價差,核課所得稅以及財政部在民國93年4月30日發布員工認股權證課稅行政命令,依照財政部當初的規劃,在執行日課徵員工認股權證的所得稅之兩事件期)中發現以面額或價差課稅之消息初步規劃和發布,確實對市場造成負向異常報酬。而有利員工之認股選擇權租稅政策消息發布(即財政部未對課稅政策做出最後決定)時,市場對資訊電子業股價產生正向累積異常報酬。 另外,研究亦發現,不利員工之員工認股選擇權課稅行政命令發布之特定事件時期,發行比例愈高及發行員工認股權之公司,過去研究發展支出愈高者,將產生較小之負向累積異常報酬。 相較於員工分紅入股制度,員工認股選擇權之激勵效果更能提供長期之誘因,但單就對工之課稅制度而言,收到的似乎是相對不利之懲罰效果。 / In this thesis, event study methodology is employed to examine the electronics industry’s stock market reaction to the announcement of tax policy changes of employee stock option. Market model and Ordinary Least Square (OLS) are adopted to estimate abcdrmal returns (AR) and accumulated abcdrmal returns (CAR) during event periods. A related issue also examined is the relation between the ratio of employee’s stock options and the CAR. Specifically, the effects of five events are examined. The first、second and fifth event (when Minister of Finance proposed to tax employee Stock options based on their par value. The second is when the Ministry of Finance announced that employee stock options would be taxed at the difference between the market price employee execute the option and the execute price.The fifth event is when Minister of Finance indeed announced an administrative decree) really show up the negative CAR. Findings concluded by the thesis are as follows: 1. When the Finance Minister proposed to tax employee stock options based on their par value or at the difference between the market price employee execute the option and the execute price, electronics companies on average had negative CAR. 2. During the fifth event period, companies with higher ratio of employee stock options and R&D expenses had lower negative CAR than those with lower ratio of employee stock options and R&D expenses.
147

Impacts of climate, topography, and weathering profile on vadose zone hydrology and coastal pine plantation management : a multi-scale investigation, Southeast Queensland, Australia

Wang, Qing January 2008 (has links)
Exotic pine plantations are a major landuse within the coastal lowlands of southeast Queensland, extending from close to the shoreline to the hinterland ranges. These plantations are within a sub-tropical climatic zone, and in most years, the summers are appreciably wetter than the winters. This terrain, in general, has been highly weathered and the soils are poor in nutrients. Environmental factors such as the climate, topography and weathering profile (including soil) are found to be important controls on vadose zone hydrology, which, in turn, has a great impact on tree growth and consequently on the design of management practices. This research project takes a holistic approach to investigate the influence of these environmental factors at different scales, and is designed to fulfil the following objectives: (1) To build a spatial model of forest productivity for the entire Tuan Toolara State Forest (TTSF), southeast Queensland, by analysing the spatial patterns of many environmental variables that may have controls on soil water distribution. (2) To determine how some of these environmental factors are responsible for the development of water-logging and soil salinisation by examining in detail an area of low site index that is severely affected by these two processes. (3) To develop a model to assess the risks of water-logging spatially and temporally. A multiple regression model was constructed to predict the forest productivity (measured by the value of site index, the average dominant tree height at 25 years of age). The independent variables were derived from a digital elevation model (elevation, slope, curvature, hillshade, flow accumulation and distance to streams), γ-ray spectrometry (potassium, thorium and uranium), and interpolated rainfall. The model explained up to 60% of the variance in the site indices and produced predictive maps of site index for two species: P. elliottii Engelm. and Queensland hybrid, a P. elliottii × P. caribaea Morelet hybrid. The model also identified the lowest site index area at the northern Tuan State Forest (NTSF), likely due to a greater risk of water-logging and salinisation. The NTSF area is of low relief and, therefore, the focus has been on the vertical controls of deep weathering profile. The methodology included setting up a network of groundwater bores screened at different depths within the weathering profile, characterising the profile (mineralogy, EC, and pH) and the groundwaters within it (water levels, physico-chemical parameters, major and minor ions). It is found that water-logging is caused by perched groundwater formed on top of the ferricrete or mottled saprolite after prolonged rainfall. Localised salinisation is related to the discharge of brackish groundwater occurring within the mottled saprolite. The deep aquifer within the coarse saprolite is fresh and not responsible for salinisation, a situation that differs from many other settings in Australia. The ability of using the Soil and Water Assessment Tool (SWAT) computer model to simulate soil water balance and to assess the risks of water-logging was tested in a selected catchment in the TTSF. The model successfully simulated stream flow at 2 weirs for a period of 6 years; the achieved R2 were 0.752 and 0.858, respectively. Long-term simulation for a 30-year period showed that there are pronounced seasonal patterns in rainfall and evapotranspiration as well as in soil water. For mature plantation with slopes of 3-15%, the mean annual duration of water-logging ranged from 161 days in the humus podzols, to 110 days in the gleyed podzolic, and to 90 days in the yellow podzolics. The outcomes of this research suggest that forest management can be strongly supported by understanding the impacts of these environmental factors (e.g. climate, topography and weathering profile) on vadose zone hydrological processes; the selection of optimum approach will depend on the research objective or purpose. The models and analytical tools that were developed or tested here have the potential to be successfully applied elsewhere if the input data are available.
148

The relationship between leadership styles and organisational climate

Cloete, Madelein 04 1900 (has links)
This study explored the relationship between leadership styles and organisational climate by means of quantitative research. Data from an organisational climate survey was used during the analysis. The results indicate that there was a positive correlation (0,749 at the 0,01 level) between leadership styles and organisational climate, thus supporting the research hypothesis. A standard multiple regression analysis was conducted and three leadership styles were found to predict 55,6% of the variance in organisational climate. The Authoritative leadership style made the largest unique contribution to the variance in organisational climate. The interaction between biographical and organisational variables and leadership styles and organisational climate was studied by means of t-tests and ANOVAs. Although statistically significant differences were found, these terms were of little practical significance and the effect sizes were generally small. The study concludes with recommendations for Industrial and Organisational Psychology practices and further research. / Industrial and Organisational Psychology / M.A. (Industrial and Organisational Psychology)
149

[en] DESIGN-MANUFACTURING INTEGRATION IMPACT ON MANUFACTURING OPERATIONAL PERFORMANCE / [pt] IMPACTO DA INTEGRAÇÃO DE PROJETO E MANUFATURA NO DESEMPENHO OPERACIONAL DE MANUFATURA

PAULA SUCLLA FERNANDEZ 11 July 2016 (has links)
[pt] Esta dissertação aborda o tema de Integração de Projeto e Manufatura, designado pelo acrônimo inglês de DMI (Design-Manufacuring Integration). Trata-se de um novo e crescente campo de pesquisa dentro da Gerência de Operações. DMI é definido como um conjunto de práticas de integração, coordenação e colaboração, que unificam diferentes áreas funcionais da organização (e.g., vendas, marketing, desenvolvimento de novos produtos, manufatura e compras) com a finalidade de criar valor e impacto no desempenho das empresas. Nas últimas décadas, as organizações estão enfrentando uma feroz concorrência e competem simultaneamente em qualidade, eficiência, flexibilidade e entrega de produtos cada vez mais complexos, com ciclos de vida mais curtos e demandas flutuantes. Por conseguinte, requerimentos de sistemas de planejamento e controle em empresas de manufatura são cada vez mais complexos. Esse contexto levanta a seguinte questão de pesquisa: Em diferentes contextos do ambiente em que se desenvolve a organização, as práticas de integração produzem o mesmo impacto sobre o desempenho? Resultados da pesquisa apontam para uma escassez de pesquisas empíricas rigorosas sobre o impacto do DMI no desempenho operacional da manufatura, sob a lente de efeitos moderadores da incerteza do mercado e da complexidade do mercado. Incerteza é entendida como a falta de habilidade de predizer ou prever devido à aleatoriedade do ambiente externo, que não pode ser alterado pelas ações das empresas individuais ou gerentes; e complexidade é entendido como sendo o estado ou qualidade de ser intricado ou complicado. O objetivo principal da Dissertação é identificar e medir o impacto do DMI sobre o desempenho operacional da manufatura, sob o efeito moderador da Complexidade da manufatura e da Incerteza do mercado. Os dados de 725 produtos da indústria de metal e fabricantes de máquinas (ISIC 3.1, código 28-35) foram obtidos em 21 países a partir da quinta rodada do International Manufacturing Strategy Survey e foram usados para testes das hipóteses. As escalas foram validadas por meio da análise fatorial confirmatória e analisadas com regressão múltipla hierárquica passo a passo. DMI impacta positivamente em três dimensões do desempenho operacional da manufatura (qualidade, flexibilidade e entregas). Complexidade da manufatura modera a flexibilidade e entrega, mas não a qualidade. A incerteza do mercado não apareceu como um moderador para a relação entre a DMI e desempenho operacional da manufatura. Profissionais devem perseguir implementações do DMI, em níveis mais elevados de complexidade de manufatura. Mais pesquisas devem se concentrar na incerteza do mercado, e fortalecer o construto de incerteza com a incerteza tecnológica. / [en] Design-Manufacturing Integration (DMI) is a new and growing research field in Operations Management. The primary goal of the Dissertation is to identify and measure the DMI impact on manufacturing operational performance. The research findings point to a paucity of rigorous empirical research on the impact of DMI on manufacturing operational performance under the lens of moderating effects of market uncertainty and market complexity. Data from 725 metal products and machinery manufacturers (ISIC 3.1, code 28-35) in 21 countries from the fifth round of the International Manufacturing Strategy Survey was used for hypotheses tests. Scales were validated with confirmatory factor analysis and analyzed with hierarchical stepwise multiple regressions. DMI positively impact on the three dimensions of manufacturing operational performance (quality, flexibility, and delivery). Manufacturing complexity moderates flexibility and delivery but not quality. Market uncertainty did not appear as a moderator for the relationship between DMI and manufacturing operational performance. Practitioners should pursue DMI implementations, under higher levels of manufacturing complexity. Further research should focus on market uncertainty, and strengthen the construct of uncertainty with technological uncertainty.
150

Modelo multiobjetivo de análise envoltória de dados combinado com desenvolvimento de funções empíricas e otimização via simulação Monte Carlo / Multi-objective data envelopment analysis model combined with empirical function development and optimization via Monte Carlo simulation

Figueiredo, Marcelo Vilela [UNESP] 31 March 2017 (has links)
Submitted by MARCELO VILELA FIGUEIREDO null (marcelo_mvf@yahoo.com.br) on 2017-05-25T23:07:30Z No. of bitstreams: 1 Dissertação.pdf: 1014783 bytes, checksum: 22908ac56d455abd6c044c5f2ad518ac (MD5) / Rejected by Luiz Galeffi (luizgaleffi@gmail.com), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: O arquivo submetido não contém o certificado de aprovação. O arquivo submetido está sem a ficha catalográfica. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija esta informação e realize uma nova submissão com o arquivo correto. Agradecemos a compreensão. on 2017-05-30T16:26:10Z (GMT) / Submitted by MARCELO VILELA FIGUEIREDO null (marcelo_mvf@yahoo.com.br) on 2017-05-30T21:46:52Z No. of bitstreams: 1 Dissertação - Marcelo Vilela Figueiredo.pdf: 1210959 bytes, checksum: 8c48e557b53c5d68ac46ba054aedee03 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-05-31T12:49:55Z (GMT) No. of bitstreams: 1 figueiredo_mv_me_guara.pdf: 1210959 bytes, checksum: 8c48e557b53c5d68ac46ba054aedee03 (MD5) / Made available in DSpace on 2017-05-31T12:49:55Z (GMT). No. of bitstreams: 1 figueiredo_mv_me_guara.pdf: 1210959 bytes, checksum: 8c48e557b53c5d68ac46ba054aedee03 (MD5) Previous issue date: 2017-03-31 / O controle de qualidade é um dos principais pilares para um bom rendimento de uma linha produtiva, visando garantir maior eficiência, eficácia e redução de custos de produção. A identificação de causas de defeitos e o controle das mesmas é uma atividade relativamente complexa, devido à infinidade de variáveis presentes em determinados processos. Na produção de itens à base de aço fundido, objetiva-se reduzir defeitos de fundição (rechupes, trincas, problemas dimensionais, entre outros), os quais podem ser ocasionados por diversas variáveis de processo, tais como: composição química do aço, temperatura de vazamento e propriedades mecânicas. Em virtude disso, o presente trabalho foi desenvolvido em uma indústria siderúrgica de grande porte, a qual atua na produção de componentes ferroviários e industriais. Por meio de sua extensa base de dados, foram avaliadas as eficiências dos produtos produzidos, sendo os mesmos denominados DMU (Decision Making Units). Para tal foi aplicada a BiO-MCDEA (Bi Objective Data Envelopment Analysis) em sete DMUs produzidas à base de aço fundido em função de 38 variáveis de processos. Nesta aplicação foram evidenciadas as variáveis de processos (input/output) influentes na determinação da eficiência das DMUs. Uma vez obtidos tais resultados, foram desenvolvidas funções empíricas para as variáveis respostas em função das variáveis de processos influentes por meio de regressão não-linear múltipla. Por fim foi realizada a Otimização via Simulação Monte Carlo de forma a determinar com quais valores se deve trabalhar com cada input para a otimização das funções empíricas. Os resultados obtidos foram satisfatórios, sendo bem condizentes com a realidade da empresa e a abordagem aplicada por meio da combinação de diferentes ferramentas se mostrou aderente à realidade estudada, e também inovadora. / Quality control is one of the pillars to guaranty a good yield on a production line, aiming to reach better efficiency, effectiveness and reduction of production costs. The identification of defects causes and its control is an activity relatively complex, due to the infinity of variables on some process. One of the most important objectives on a Steel Castings Parts production is to reduce castings defects (shrinkage, cracks, dimensional problems, etc.), that can be caused by several process variables, such asChemical Composition, Pouring Temperature and Mechanical Properties. Due to the mentioned explanations, this study was developed at a large steel industry, which produces rail and industrial parts. The efficiency of the produced parts, called DMU (Decision Making Units), was analyzed through an extensive data base. It was done by using BiO-MCDEA (Bi Objective Data Envelopment Analysis) on seven DMUs, which are steel casting parts, in function of 38 process variables. Additionally, the process variables influents on the DMU’s efficiency determination were evidenced through the mentioned implementation. Once those results were obtained, empirical functions were developed for the response variables in function of the influents process variables through multiple non-linear regression. Finally an optimization via Monte Carlo Simulation was implemented in order to determine the inputs values necessary to optimize the empirical functions. The achieved results were satisfactory, being consistent with the industry’s reality and the applied methodology through the combination of different tools were effectiveness and innovative.

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