12,881 research outputs found
Aplicación de la teoría de colas en la bodega de repuestos y materiales en el área de producción del Ingenio Santa Ana S. A.
No full textRealizar un estudio de teoría de colas sobre la situación actual en la bodega. Aplicar un modelo de teoría de colas en la bodega de repuestos y materiales en el área de Producción del Ingenio Santa Ana S. A
Teoría de Colas
No full textEl objetivo de la Teoría de Colas es el estudio matemático del comportamiento de las colas o líneas de espera, se enmarca en el área de la Investigación Operativa. Presentes en nuestro día a día, las colas aparecen cuando la demanda de un servicio es superior a la capacidad de servicio del sistema.
La Teoría de Colas proporciona información para la toma decisiones de capacidad óptima y diseño de sistemas.
En este proyecto se llevará a cabo una revisión de la Teoría de Colas y de sus modelos más utilizados, los cuales se ejemplificarán para obtener una visión práctica de cómo funciona el estudio de las líneas de espera. Se realizará un análisis de la capacidad de servicio y costes asociados a los sistemas de colas.
The objective of the Queueing theory is the mathematical study of the behaviour of queues or lines of waiting, framed in the area of Operational Research. Present in our day to day lives, queues appear when the demand for a service is higher than the service capacity of the system. Queueing Theory provides information for decision-making regarding optimal capability and systems designs.
This project will carry out a review of the Theory of Queues and the most common queue models, which will be exemplified to obtain a practical vision of how the study of waiting lines works. An analysis of service capabilities and costs associated with queuing systems shall be carried out
Differential stability of 2'F-ANA*RNA and ANA*RNA hybrid duplexes: roles of structure, pseudohydrogen bonding, hydration, ion uptake and flexibility
No full text14 pags., 7 figs., 3 tabs.Hybrids of RNA with arabinonucleic acids 2′F-ANA and ANA have very similar structures but strikingly different thermal stabilities. We now present a thorough study combining NMR and other biophysical methods together with state-of-the-art theoretical calculations on a fully modified 10-mer hybrid duplex. Comparison between the solution structure of 2′F-ANA•RNA and ANA•RNA hybrids indicates that the increased binding affinity of 2′F-ANA is related to several subtle differences, most importantly a favorable pseudohydrogen bond (2′F-purine H8) which contrasts with unfavorable 2′-OH-nucleobase steric interactions in the case of ANA. While both 2′F-ANA and ANA strands maintained conformations in the southern/eastern sugar pucker range, the 2′F-ANA strand's structure was more compatible with the A-like structure of a hybrid duplex. No dramatic differences are found in terms of relative hydration for the two hybrids, but the ANA•RNA duplex showed lower uptake of counterions than its 2′F-ANA•RNA counterpart. Finally, while the two hybrid duplexes are of similar rigidities, 2′F-ANA single strands may be more suitably preorganized for duplex formation. Thus the dramatically increased stability of 2′F-ANA•RNA and ANA•RNA duplexes is caused by differencesin at least four areas, of which structure and pseudohydrogen bonding are the most important. © The Author(s) 2010. Published by Oxford University Press.Spanish Ministerio de Ciencia e Innovacion (grants
CTQ2007-68014-C02-02 to CG and BIO2009-10964 to
MO); Fundacion Marcelino Botin (grant to MO);
Canadian Institutes for Health Research (grant to
M.J.D.); Natural Sciences and Engineering Research
Council of Canada (postgraduate scholarship to
J.K.W.). Funding for open access charge: Canadian
Institutes for Health Research
Analysis of information use in agricultural science PhD theses at Central University of Venezuela
No full textPurpose – To analyze information use in agricultural science PhD theses submitted between 1986 and 2002 in the Faculty of Agronomy, Central University of Venezuela (UCV).
Design/methodology/approach – The source of information was the UCV Faculty of Agronomy, Library's database, “Tesis”. The unidimensional production and use indicators analyzed included: scientific production, reference density, self-citations, document contemporaneousness and type of documents cited, reference scattering and accessibility of the journals cited.
Findings – The analysis of the data obtained from 4,646 bibliographic references in 42 agricultural science PhD theses provides insight into information use in a Venezuelan agricultural science community. The mean number of references per thesis found was 113?±?21. The number of women earning a PhD in agriculture was observed to grow. The percentage of self-citations varied widely. The half-life was 11 years and the Price's Index 22 per cent. According to the distribution by document type, most of the publications cited were articles in journals, while references to technical standards and internet publications were rare. UCV Faculty of Agronomy PhD students tended to seek information primarily in the Anglo Saxon literature. The Celestino Bonfanti Library periodicals section met a high proportion (92 per cent) of the demand for journals located in the first and second concentration-scattering zones.
Originality/value – This is the only paper on the evaluation of PhD theses in Venezuela. The findings will be useful for education planners in Venezuela and other developing countries.Publicad
Representações da sexualidade na obra de Ana Saldanha
No full textMestrado em Línguas, Literaturas e CulturasA presente dissertação analisa as diferentes representações da sexualidade na obra literária para jovens de Ana Saldanha. A leitura analítica incide sobre as narrativas da autora que abordam a temática da sexualidade juvenil e as suas problemáticas, com o objetivo de estudar a forma como as mesmas contribuem para a construção da identidade pessoal e sexual do potencial recetor juvenil. Desta forma, pretende-se detetar os conflitos psicológicos dos protagonistas, os seus valores e problemas, assim como os novos valores, problemas e preocupações sociais que emergem das narrativas; compreender de que forma a autora exprime a sua capacidade em observar o quotidiano e as relações humanas; identificar os pilares em que se apoia o universo social em estudo (família, escola, grupo de amigos); enquadrar as personagens numa sociedade pós-industrial e de informação que exige ao adolescente uma superação de desafios e de novos problemas.This dissertation analyzes the different representations of sexuality in Ana Saldanha’s literary work for youth. The analytical reading focuses on the author's narratives that address the issue of teenage sexuality and its problems, aiming to study their contribution in the construction of personal and sexual identity of the potential juvenile receiver. Thus, it is intended to detect the psychological conflicts of the protagonists, their values and problems, as well as the new values, social concerns and problems that emerge from the narratives; understand how the author expresses her ability to observe daily life and human relations; identify the pillars on which relies the social universe under study (family, school, friends); framing the characters in a post-industrial and information society which requires the teenager to relentlessly surmount challenges and new problems
Teoría de Colas
No full textEn la teoría de colas hay diferentes modelos, en este trabajo se explican teóricamente los modelos más generales que se hallan en nuestras vidas con más frecuencia. Los modelos expuestos en este trabajo son explicados como procesos de nacimiento y muerte, donde nacimiento indica la entrada de un cliente al sistema y muerte la salida de este. Mi estudio se basará en explicar los elementos fundamentales del sistema de colas, así como los modelos donde el tiempo entre llegadas de clientes y el tiempo de servicio seguirán una distribución exponencial. Dicha distribución es la más utilizada debido a sus propiedades de función de densidad estrictamente decreciente y pérdida de memoria, donde las llegadas solo van a depender del momento en el que llegan al sistema. Además, explicaré los modelos más destacados con distribuciones no exponenciales. Para poder comprender todo lo anterior, es necesario clasificar el sistema de colas previamente según su estructura y elementos principales, entre otros: fuente de entrada, cola y mecanismo de servicio. El objetivo de este estudio es mejorar los sistemas de servicio y encontrar un equilibrio entre los costes y el tiempo de espera.In the theory of tails there are different models, in this work theoretically explain the more general models found in our lives more often. The models exposed in this work are explained as birth and death processes, where birth indicates the entry of a client into the system and death the exit from it. My study will be based on explaining the fundamental elements of the queue systems, as well as the models where the time between customer arrivals and service time will follow an exponential distribution. This distribution is the most commonly used due to its strictly decreasing density and memory loss function properties, where arrivals will only depend on when they arrive in the system. In addition, I will explain the most outstanding models with non-exponential distributions. In order to understand all the above, it is necessary to classify the queue system previously according to its structure and main elements, among others: input source, queue and service mechanism. The aim of this study is to improve service systems and find a balance between costs and the amount of waiting
Teoría de Colas aplicada a la Administración de Empresas
No full textLa Teoría de Colas es el conjunto de herramientas matemáticas utilizadas para estudiar el comportamiento de las líneas de espera o colas que se producen porque, en un determinado momento, la demanda de un bien o servicio sobrepasa la capacidad que tiene el sistema para suministrar dicho bien o servicio. El objetivo de este trabajo es realizar una introducción a la Teoría de Colas y estudiar algunos de los modelos más utilizados por las empresas. Para ello, se van a analizar las medidas de rendimiento de estado estable de esos modelos y se van a aplicar en algunos ejemplos, con el fin de aprender a interpretar tanto los datos como los resultados. También se incluye el estudio económico de un sistema de colas que nos ayudará a hacer un balance entre el coste de ofrecer el servicio y el coste asociado a la espera de clientes para obtener ese servicio.The Queueing Theory integrates mathematical tools that are used to study the behaviour of the waiting lines or queues that are produced because the demand for a good or service exceeds the capacity of the system to supply the good or service at a given time. The objective of this work is to do an introduction to the Queueing Theory and to study some of the models most commonly used by companies. For this propuse, the steady-state performance measures of these models will be analyzed and applied to some examples in order to learn how to interpret both the data and the results. In addition, this work includes the economic study of a queueing system that will help us to balance the cost os offering the service and the cost associates with customers waiting for that service
Viajantes ex-cêntricas nas histórias de Ana Miranda
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em Literatura.No conjunto das narrativas ficcionais da escritora brasileira Ana Miranda, a temática da viagem # considerada uma das mais férteis da literatura ocidental de todos os tempos # ocupa um espaço de centralidade, podendo até mesmo ser vista como o mais importante eixo de estruturação de suas obras. O estudo realizado pela presente tese tem por objetivo analisar o tratamento dado ao tema da viagem nos romances Desmundo, O retrato do rei, Dias & Dias e Amrik, evidenciando que por intermédio das narradora-viajantes # Oribela, Mariana, Feliciana e Amina # a autora promove um diálogo entre diferentes culturas, gêneros, etnias e gerações, ao mesmo tempo em que estabelece um profícuo diálogo com o passado em sua invariante problematização concernente aos limites e cruzamentos entre o discurso ficcional e os discursos narrativos extraliterários que o cercam, sobretudo o histórico e o biográfico. In the whole of Brazilian writer Ana Miranda#s fictional narrative, the travel thematic # considered one of the most fertile themes of the western literature of all times # occupies a central space, and can even been seen as the most important structuring axis of Miranda#s works. The aim of the present thesis is to analyze the treatment given to the travel subject in the novels Desmundo, O retrato do rei, Dias & Dias and Amrik, emphasizing that, through the traveling narrators, Oribela, Mariana, Feliciana and Amina, the author promotes a connection between different cultures, genders, ethnics and generations, at the same time that establishes a profitable dialogue with the past in her invariant problematization concerning the limits and crossings between the fictional and the extra-literary narrative discourses that surrounds it, mainly the historical and the biographic ones
Séquence 4, Ana et la télévision, raconté par Ana
No full textCette séquence fait partie du corpus vidéo de Langue des Signes Emergentes utilisé lors de la thèse d'Ivani Fusellier-Souza : la locutrice Ana raconte qu'elle aime regarder la télé, bien que ne peut l'écouter. Alors que sa mère ne la regarde pas.00:00:00>00:00:03 La sœur demande à Ana si elle aime bien regarder la télévision. 00:00:04>00:00:07 Ana dit qu'ils ont une télé là-bas. 00:00:07>00:00:15 La sœur demande à nouveau à Ana si elle aime ou non la télé. 00:00:15>00:00:19 La mère dit qu'il faut faire attention, car si on allume la télé, Dieu nous punira. 00:00:19>00:00:48 Ana et sa sœur discute sur le fait qu'Ana ne peut pas écouter la télé et peut seulement la regarder, alors que ses sœurs peuvent l'écouter. 00:00:48>00:01:09 La sœur lui demande ce qu'elle pense des filles à la télé en mini-jupe avec des débardeurs et du rouge à lèvres. 00:01:09>00:01:35 Ana dit qu'elle n'aime pas comme sa sœur les filles qui s'habillent comme cela. 00:01:35>00:01:39 La mère dit que de toute façon, Dieu les punira. 00:01:40>00:01:53 Ana explique qu'elle regarde la télé avec ses sœurs mais que sa mère ne la regarde pas
Avaliação do desempenho de colas Hot-Melt para embalagens alimentares
No full textMestrado em Engenharia QuímicaA aplicação de adesivos para fixação é, hoje em dia, a nível de produção industrial, a opção mais utilizada para executar a adesão ou fixação de diferentes superfícies, sendo produzida uma grande variedade de produtos utilizando este método de fixação, como por exemplo, livros, rolhas de cortiça, caixas de cartão e embalagens.
Existem três grupos de adesivos, que se dividem consoante a utilização e diferentes tipos de solventes. Há os adesivos de base solvente, os adesivos de base aquosa e os adesivos sem solvente, dos quais os mais utilizados são os adesivos “hot-melt”.
O presente trabalho teve como objectivo a avaliação de desempenho e características de diferentes colas “hot-melt” para a produção de embalagens de produtos alimentares. Desta forma, realizaram-se diversos estudos a nível das propriedades físicas e químicas das colas bem como a interacção das mesmas com as superfícies a ser utilizadas.
Com a realização de diversos testes, nomeadamente, espectroscopia FTIR, determinação dos ângulos de contacto, análise TGA, DSC e DMA, foi possível determinar qual a melhor cola a utilizar na linha de colagem, assim como determinar se as condições ambientais às quais as superficies são expostas alteravam a capacidade de adesão das colas e se as condições de aplicação destas seriam as ideais.
Os resultados obtidos permitiram chegar à conclusão de que a melhor cola a utilizar será a cola denominada HMB.Adhesives are the option that nowadays most industries choose to perform joints amongst two or more surfaces, and a great variety of products are made using this method, naming some examples, books, cork stoppers, packages, card boxes.
Adhesives are usually sorted in three major groups, according to their uses and solvent composition. The three groups are, solvent based, water based and solvent free adhesives, within this last group hot-melt adhesives are the most used.
The objective of this thesis was evaluating the performance and characteristics of different hot-melt adhesives in food grade packages. Several studies were made to characterize the glue and surface physical and chemical properties and also studies to characterize the interactions between the two.
FTIR, TGA, DSC, DMA and contact angle analysis , made possible to determine which glue is the one to use in the gluing line, these also made possible to determine if the environmental conditions to which the surfaces are subjected to altered surfaces wettability. Study results shows that HMB glue is the one that fills all criteria
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