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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

SCAT Model Based on Bayesian Networks for Lost-Time Accident Prevention and Rate Reduction in Peruvian Mining Operations

Ziegler-Barranco, Ana, Mera-Barco, Luis, Aramburu-Rojas, Vidal, Raymundo, Carlos, Mamani-Macedo, Nestor, Dominguez, Francisco 01 January 2020 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Several factors affect the activities of the mining industry. For example, accident rates are critical because they affect company ratings in the stock market (Standard & Poors). Considering that the corporate image is directly related to its stakeholders, this study conducts an accident analysis using quantitative and qualitative methods. In this way, the contingency rate is controlled, mitigated, and prevented while serving the needs) of the stakeholders. The Bayesian network method contributes to decision-making through a set of variables and the dependency relationships between them, establishing an earlier probability of unknown variables. Bayesian models have different applications, such as diagnosis, classification, and decision, and establish relationships among variables and cause–effect links. This study uses Bayesian inference to identify the various patterns that influence operator accident rates at a contractor mining company, and therefore, study and assess the possible differences in its future operations.
2

Development of the method in multimedialization of Environmental science and technology courses

T.J. Juang, Simon 26 June 2003 (has links)
This purpose of this study was to develop the method in multimedia of environmental science and technology courses. The advanced net-work streaming technology was presented to edit the environmental science and technology courses. A development method combined vision technology and engineering experiments was to fulfill the eport of multimedia. In this work, we found (1) the interrelating ability of editing soft wares in production of above courses was very important; (2) to make a satisfactory works, a balancing decision was need between expected good result and limited budget; (3) as for net-work wide frequency extended and soft ware technology developed, the designer of courses must be careful the upgrade in editing soft wares in order to increase the courses broadcast; (4) used the practical teaching in topics, it could be training the real operation and resolving ability in problem on students; (5) a unique method correlated the record in experiment procedures to be a final report by vision technology; (6)presented a vision in multimedia of report to the project offer, to increase the trust and responsibility for works.
3

New insights on financing and business development of start-up firms and SMEs

Jonsson, Sara January 2009 (has links)
This thesis aspires to advance understanding of how start-up firms’ and small and medium sized firms’(SMEs) network relationships affect acquisition of financing and information necessary to achieve firmbusiness development through the exchange in business relationships. It contributes to research on socialstructure by clarifying how network relationships that facilitate exchange have a positive effect on firmbusiness development, defined as subjective and objective enhancement of firm performance. The empirical setting consists of case studies in entrepreneurial start-up firms and of quantitative researchin SMEs. The findings show that in the start-up phase of firm development, network relationships that areembedded in social attachment and shared cognitive schemes constitute means to acquire informationcontaining referrals to new business partners, thus affecting the structural development of start-ups firms’business network. Findings further show that relationships to banks are important in order to fund thisstructural development. The thesis also shows the effects of banks, as institutional actors, on SMEs’investments in international business relationships and the effects of such investments on SMEs’ businessdevelopment. It is shown that relationships to domestic and local banks in different ways affect SMEs’specific investments in international business relationships. A local bank relationship decreases the SME’srelationship specific investments, while a domestic bank relationship increases relationship specificinvestments. There is however an indirect positive effect of a local bank relationship on the SME’srelationship specific investments, mediated by a positive effect of the SME’s relationships to other localinstitutional actors. The results further show that increases in relationship specific investments promoteSMEs’ business development. Findings made in this thesis also show that institutions, experiencedthrough interaction in the international business relationship, positively affect relationship specificinvestments and the performance enhancement of such investments. A general conclusion drawn fromthe findings presented in this thesis is the relevance of a type of actor - actors that facilitate exchangesamong firms and their business partners who are, or wish to be, independent - to the businessdevelopment of start-ups and SMEs. This thesis challenges banks to increase cognitive alignment with customers of start-up firms and toconsider corporate customers in view of their business relationships and network structure. Theseapproaches are suggested to facilitate bank’s assessment of firm creditworthiness. / <p>QC 20100722</p>
4

MIZENÍ A CHYBĚNÍ / MISSING AND DISAPPEARING

Langer, Jan January 2017 (has links)
This work documents the author's interest in drawing and is based on the mental background of his artistic creation. The work is guided by the interest in the physical conditions of the drawing itself (materiality of the drawing), but also in the study of drawing as a fluid material of artistic creation, entering into the relationship with the image (drawing as a material). At the same time it deals with the process of creation itself and the phenomenon of repetition. The primary goal of the whole work is not the deliberate laying of pre-formulated questions and the subsequent search for their answers, the presentation of some finished truths, or the mere illustration of a certain issue, but rather the process of finding questions that emerge during the process of creation itself.
5

Robust Reinforcement Learning in Continuous Action/State Space

Grönland, Axel, Eriksson Möllerstedt, Viktor January 2020 (has links)
In this project we aim to apply Robust Reinforce-ment Learning algorithms, presented by Doya and Morimoto [1],[2], to control problems. Specifically, we train an agent to balancea pendulum in the unstable equilibrium, which is the invertedstate.We investigate the performance of controllers based on twodifferent function approximators. One is quadratic, and the othermakes use of a Radial Basis Function neural network. To achieverobustness we will make use of an approach similar toH∞control, which amounts to introducing an adversary in the controlsystem.By changing the mass of the pendulum after training, we aimedto show as in [2] that the supposedly robust controllers couldhandle this disruption better than its non-robust counterparts.This was not the case. We also added a random disturber signalafter training and performed similar tests, but we were againunable to show robustness. / I detta projekt applicerar vi Robust Rein- forcement Learning (RRL) algoritmer, framtagna av Doya och Morimoto [1], [2], på reglerproblem. Målet var att träna en agent att balansera en pendel i det instabila jämviktsläget; det inverterade tillståndet. Vi undersökte prestandan hos regulatorer baserade på två value function approximators. Den ena är kvadratisk och den andra en Radial Basis Function neuralt nätverk. För att skapa robusthet så använder vi en metod som är ekvivalent med H∞ - reglering, som innebär att man introducerar en motståndare i reglersystemet. Genom att ändra pendelns massa efter träning, hoppas vi att som i [2] kunna visa att den förment robusta regulatorn klarar av denna störning bättre än sin icke-robusta mostvarighet. Detta var inte fallet. Vi lade även till en slumpmässig störsignal efter träning och utförde liknande tester, men lyckades inte visa robusthet i detta fall heller. / Kandidatexjobb i elektroteknik 2020, KTH, Stockholm
6

Análise qualitativa do ciclo real e tempo de combustão em um motor padrão ASTM-CFR operando com mistura de gasolina e etanol hidratado

Malfatti, Laércio January 2009 (has links)
A duração da combustão tem implicação direta na determinação do trabalho negativo no ciclo motor. A duração da combustão tem relação inversa com a velocidade de propagação da chama. Assim, quanto maior a velocidade de propagação da chama, menor a duração da combustão. Além disto, a duração da combustão está relacionada com a relação volumétrica de compressão, com a razão de mistura e com o tipo de combustível, entre outros fatores. Neste sentido, quanto maior a velocidade de queima da mistura ar-combustível, menor o trabalho negativo no ciclo. Neste contexto, foram ensaiadas 3 relações de compressão e 3 razões de mistura, para 6 combustíveis de composição conhecida: gasolina comum tipo C, álcool etílico hidratado combustível (AEHC) e AEHC adicionado à gasolina comum tipo C nas proporções de 20%, 40%, 60% e 80%. A variação da pressão no interior da câmara de combustão, para todos os combustíveis, e a posição da centelha de ignição foram determinadas com a utilização da base angular e com variação da relação volumétrica de compressão e da razão de mistura. O diagrama , para fins de cálculo de área, foi traçado por pós-processamento. Os resultados obtidos indicam que a duração da combustão aumenta com o aumento da razão de mistura e diminui com o aumento da relação volumétrica de compressão, para todos os combustíveis ensaiados. Verificou-se que a amplitude da pressão, no interior da câmara de combustão, se comporta inversamente à duração da combustão. Mostrou-se que o aumento da razão de mistura implica na redução do trabalho líquido entregue ao êmbolo ao longo de todo o ciclo do motor. Opostamente ocorre com o aumento da relação volumétrica de compressão, que implica no aumento do trabalho líquido por ciclo. Concluiu-se que o máximo valor para o trabalho líquido ao longo de todo o ciclo foi obtido para a maior relação volumétrica de compressão (8:1) e a menor razão de mistura (λ = 0,9). O combustível que representou este resultado foi o álcool etílico hidratado combustível adicionado à gasolina comum tipo C em 80% (AEHC80). O mínimo valor para o trabalho líquido, ao longo de todo o ciclo foi obtido, para a menor relação volumétrica de compressão (6:1) e a maior razão de mistura dos ensaios (λ = 1,1). O combustível que representou este resultado foi o álcool etílico hidratado combustível (AEHC). / The duration of the combustion is directly implicative on determining the negative work of the motor cycle. The duration of the combustion has an inverse relation with the flame propagation speed. Thus, the higher propagation of the flame, the shorter duration of the combustion. Besides that, the duration of the combustion is related to the relation of compression, to the air/fuel relation and to the type of fuel, among other factors. In this way, the higher burning speed of the air/fuel mixture, the smallest negative work in the cycle. In such a context, there were tried three compression relations and three mixture ratios for six fuels of know compositions: ordinary gasoline C type, combustible hydrated ethyl alcohol and combustible hydrated ethyl alcohol added to ordinary gasoline C type in the proportions of 20%, 40%, 60% and 80%. The pressure variation inside the combustion chamber, for all fuels, and the position of the ignition spark were determined using the angular base and with variation of the compression relation and the mixture ratio. The diagram, for area calculation, was traced by post processing. The obtained results indicate that the combustion duration increases with the rising of the mixture ratio and decreases with the rising of the compression relation, for all the tried combustibles. It was found that the pressure amplitude inside the combustion chamber behaves inversely to the combustion duration behavior. It was shown that the rising of the mixture ratio implies on the reduction of the net work delivered by the piston all through the cycle of the motor. The opposite occurs with the rising of the compression relation, that implies on the increase of the net work by cycle. It was concluded that the maximum value for the net work all through the cycle was obtained for the higher compression relation (8:1) and the least mixture ratio of the tests (λ = 0,9). The combustible that achieved such a result was the combustible hydrated ethyl alcohol added to ordinary gasoline C type in 80%. The least value for the net work all through the cycle was obtained by the least compression relation (6:1) and the highest mixture ratio of the tests (λ = 1,1). The fuel that achieved that result was the combustible hydrated ethyl alcohol.
7

Análise qualitativa do ciclo real e tempo de combustão em um motor padrão ASTM-CFR operando com mistura de gasolina e etanol hidratado

Malfatti, Laércio January 2009 (has links)
A duração da combustão tem implicação direta na determinação do trabalho negativo no ciclo motor. A duração da combustão tem relação inversa com a velocidade de propagação da chama. Assim, quanto maior a velocidade de propagação da chama, menor a duração da combustão. Além disto, a duração da combustão está relacionada com a relação volumétrica de compressão, com a razão de mistura e com o tipo de combustível, entre outros fatores. Neste sentido, quanto maior a velocidade de queima da mistura ar-combustível, menor o trabalho negativo no ciclo. Neste contexto, foram ensaiadas 3 relações de compressão e 3 razões de mistura, para 6 combustíveis de composição conhecida: gasolina comum tipo C, álcool etílico hidratado combustível (AEHC) e AEHC adicionado à gasolina comum tipo C nas proporções de 20%, 40%, 60% e 80%. A variação da pressão no interior da câmara de combustão, para todos os combustíveis, e a posição da centelha de ignição foram determinadas com a utilização da base angular e com variação da relação volumétrica de compressão e da razão de mistura. O diagrama , para fins de cálculo de área, foi traçado por pós-processamento. Os resultados obtidos indicam que a duração da combustão aumenta com o aumento da razão de mistura e diminui com o aumento da relação volumétrica de compressão, para todos os combustíveis ensaiados. Verificou-se que a amplitude da pressão, no interior da câmara de combustão, se comporta inversamente à duração da combustão. Mostrou-se que o aumento da razão de mistura implica na redução do trabalho líquido entregue ao êmbolo ao longo de todo o ciclo do motor. Opostamente ocorre com o aumento da relação volumétrica de compressão, que implica no aumento do trabalho líquido por ciclo. Concluiu-se que o máximo valor para o trabalho líquido ao longo de todo o ciclo foi obtido para a maior relação volumétrica de compressão (8:1) e a menor razão de mistura (λ = 0,9). O combustível que representou este resultado foi o álcool etílico hidratado combustível adicionado à gasolina comum tipo C em 80% (AEHC80). O mínimo valor para o trabalho líquido, ao longo de todo o ciclo foi obtido, para a menor relação volumétrica de compressão (6:1) e a maior razão de mistura dos ensaios (λ = 1,1). O combustível que representou este resultado foi o álcool etílico hidratado combustível (AEHC). / The duration of the combustion is directly implicative on determining the negative work of the motor cycle. The duration of the combustion has an inverse relation with the flame propagation speed. Thus, the higher propagation of the flame, the shorter duration of the combustion. Besides that, the duration of the combustion is related to the relation of compression, to the air/fuel relation and to the type of fuel, among other factors. In this way, the higher burning speed of the air/fuel mixture, the smallest negative work in the cycle. In such a context, there were tried three compression relations and three mixture ratios for six fuels of know compositions: ordinary gasoline C type, combustible hydrated ethyl alcohol and combustible hydrated ethyl alcohol added to ordinary gasoline C type in the proportions of 20%, 40%, 60% and 80%. The pressure variation inside the combustion chamber, for all fuels, and the position of the ignition spark were determined using the angular base and with variation of the compression relation and the mixture ratio. The diagram, for area calculation, was traced by post processing. The obtained results indicate that the combustion duration increases with the rising of the mixture ratio and decreases with the rising of the compression relation, for all the tried combustibles. It was found that the pressure amplitude inside the combustion chamber behaves inversely to the combustion duration behavior. It was shown that the rising of the mixture ratio implies on the reduction of the net work delivered by the piston all through the cycle of the motor. The opposite occurs with the rising of the compression relation, that implies on the increase of the net work by cycle. It was concluded that the maximum value for the net work all through the cycle was obtained for the higher compression relation (8:1) and the least mixture ratio of the tests (λ = 0,9). The combustible that achieved such a result was the combustible hydrated ethyl alcohol added to ordinary gasoline C type in 80%. The least value for the net work all through the cycle was obtained by the least compression relation (6:1) and the highest mixture ratio of the tests (λ = 1,1). The fuel that achieved that result was the combustible hydrated ethyl alcohol.
8

Análise qualitativa do ciclo real e tempo de combustão em um motor padrão ASTM-CFR operando com mistura de gasolina e etanol hidratado

Malfatti, Laércio January 2009 (has links)
A duração da combustão tem implicação direta na determinação do trabalho negativo no ciclo motor. A duração da combustão tem relação inversa com a velocidade de propagação da chama. Assim, quanto maior a velocidade de propagação da chama, menor a duração da combustão. Além disto, a duração da combustão está relacionada com a relação volumétrica de compressão, com a razão de mistura e com o tipo de combustível, entre outros fatores. Neste sentido, quanto maior a velocidade de queima da mistura ar-combustível, menor o trabalho negativo no ciclo. Neste contexto, foram ensaiadas 3 relações de compressão e 3 razões de mistura, para 6 combustíveis de composição conhecida: gasolina comum tipo C, álcool etílico hidratado combustível (AEHC) e AEHC adicionado à gasolina comum tipo C nas proporções de 20%, 40%, 60% e 80%. A variação da pressão no interior da câmara de combustão, para todos os combustíveis, e a posição da centelha de ignição foram determinadas com a utilização da base angular e com variação da relação volumétrica de compressão e da razão de mistura. O diagrama , para fins de cálculo de área, foi traçado por pós-processamento. Os resultados obtidos indicam que a duração da combustão aumenta com o aumento da razão de mistura e diminui com o aumento da relação volumétrica de compressão, para todos os combustíveis ensaiados. Verificou-se que a amplitude da pressão, no interior da câmara de combustão, se comporta inversamente à duração da combustão. Mostrou-se que o aumento da razão de mistura implica na redução do trabalho líquido entregue ao êmbolo ao longo de todo o ciclo do motor. Opostamente ocorre com o aumento da relação volumétrica de compressão, que implica no aumento do trabalho líquido por ciclo. Concluiu-se que o máximo valor para o trabalho líquido ao longo de todo o ciclo foi obtido para a maior relação volumétrica de compressão (8:1) e a menor razão de mistura (λ = 0,9). O combustível que representou este resultado foi o álcool etílico hidratado combustível adicionado à gasolina comum tipo C em 80% (AEHC80). O mínimo valor para o trabalho líquido, ao longo de todo o ciclo foi obtido, para a menor relação volumétrica de compressão (6:1) e a maior razão de mistura dos ensaios (λ = 1,1). O combustível que representou este resultado foi o álcool etílico hidratado combustível (AEHC). / The duration of the combustion is directly implicative on determining the negative work of the motor cycle. The duration of the combustion has an inverse relation with the flame propagation speed. Thus, the higher propagation of the flame, the shorter duration of the combustion. Besides that, the duration of the combustion is related to the relation of compression, to the air/fuel relation and to the type of fuel, among other factors. In this way, the higher burning speed of the air/fuel mixture, the smallest negative work in the cycle. In such a context, there were tried three compression relations and three mixture ratios for six fuels of know compositions: ordinary gasoline C type, combustible hydrated ethyl alcohol and combustible hydrated ethyl alcohol added to ordinary gasoline C type in the proportions of 20%, 40%, 60% and 80%. The pressure variation inside the combustion chamber, for all fuels, and the position of the ignition spark were determined using the angular base and with variation of the compression relation and the mixture ratio. The diagram, for area calculation, was traced by post processing. The obtained results indicate that the combustion duration increases with the rising of the mixture ratio and decreases with the rising of the compression relation, for all the tried combustibles. It was found that the pressure amplitude inside the combustion chamber behaves inversely to the combustion duration behavior. It was shown that the rising of the mixture ratio implies on the reduction of the net work delivered by the piston all through the cycle of the motor. The opposite occurs with the rising of the compression relation, that implies on the increase of the net work by cycle. It was concluded that the maximum value for the net work all through the cycle was obtained for the higher compression relation (8:1) and the least mixture ratio of the tests (λ = 0,9). The combustible that achieved such a result was the combustible hydrated ethyl alcohol added to ordinary gasoline C type in 80%. The least value for the net work all through the cycle was obtained by the least compression relation (6:1) and the highest mixture ratio of the tests (λ = 1,1). The fuel that achieved that result was the combustible hydrated ethyl alcohol.
9

Les entrepreneurs issus de l’immigration maghrébine dans la métropole parisienne : tendances associatives, perspectives d’évolution et activités économiques avec le pays d’origine / Entrepreneurs from North African immigration in the Parisian metropolis : associative tendencies, economic activities with the country of origin and perspactives of the future

Ben Khalifa, Rached 14 February 2012 (has links)
Nous avons investi l’entrepreneuriat maghrébin dans la métropole parisienne, région riche de par sa diversité culturelle, avec comme point de départ les activités associatives auxquelles adhérent nos interlocuteurs. A ce titre, nous avons identifié un certain nombre de regroupements et de réseaux crées par des entrepreneurs maghrébins et qui ont pour objectifs, notamment, de fédérer les efforts pour faire face à la concurrence domestique et de faciliter un retour entrepreneurial au pays d’origine. Sur ce plan, nous avons mis en relief les questions d’efficacité de ces associations, voir même leur transformation en entreprises.Nous avons pu évoquer avec nos interlocuteurs les aspects des diasporas maghrébines, notamment celles se rapportant aux difficultés de transmettre la culture d’origine aux descendants, les jeux avec les doubles identités ou l’assimilation avec tout ce que signifie ce mot.Nous avons aussi, évoqué les effets directs et indirects du retour entrepreneurial sur le marché des pays du Maghreb aussi bien sur le plan de l’intégration ou la désintégration économique, que sur le plan de l’emploi, les qualifications et les compétences ainsi que les modes de gouvernance./. / Absract:We discussed in this thesis the maghrebian entrepreneurial ship in Paris, This capital is known by its cultural diversity . the starting point was the association’s activities that make the business men that we meet. We have identified some entrepreneurial network. These network have as missions to federate des efforts of the maghrebian entrepreneurs to conterbalance the concurrents in France and to guarantee the best conditions for the entrepreneurial return to tha origin country in maghreb.We evoked also in this doctoral work, the aspects of maghrebian diasporas, and the difficulties to transmit the original cultures to the younger generations . the acting with the double culture and or the assimilation full integration in the host society (the frensh community) .We studied also some economic consequences of creating company in the origin country (Tunisia) by the maghrebian business men. Especially the economic desintegration or the integration through out the entrepreneurial establishement either creating compagnies or by some partenarship.Kee words: entrepreneurship, associations, network, diasporas, maghrebian, Paris, identities, culture, economic integration,
10

SUPPORT FACILITIES FOR STUDENTS IN THEIR ENTREPRENEURIAL VENTURES AT LINNAEUS UNIVERSITY : HOW CAN THE INTERNATIONAL STUDENTS SEEK AND EXPERIENCE THE SUPPORT THEY GET FROM THE UNIVERSITY TO DEVELOP THEIR ENTREPRENEURIAL VENTURES

Macarthy, Kadiatu, Yang, Wei January 2017 (has links)
We see an increasing need for more entrepreneurs to match the changing nature of the globe in this dynamic world. In 2012, the Swedish government considered entrepreneurship to be a theme running throughout the entire educational system. The university is one place to develop the entrepreneurial spirit, especially among students. Universities play a very important role in enhancing national development because of their central role in the production of high-level manpower and research that are necessary for achieving national goals. Through research, universities generate new knowledge and understanding that are instrumental for developing new technology and promoting information transfer. Most international students experience three levels of shock: culture shock, language shock and academic shock. Sohrabpour et al. (2013) defined these shocks as a disease suffered by those who enter a new cultural environment. In this paper, we discussed the role that the university plays in supporting international students to develop entrepreneurial ideas and become established at Linnea University in Växjö. We believed that if being an international student poses challenges, launching an entrepreneurial venture is sure to have even more complex constraints that will potentially kill their entrepreneurial spirit. Thus, we examined the support facilities that are available to help international students start their entrepreneurial ventures and how they are experiencing these facilities at universities. We took Linnea University in Växjö as a case study.

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