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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.
11

Realocação de pedidos de calçados em aglomerados industriais em função de grandes distúrbios na produção.

Pereira Júnior, José Feliciano 26 February 2004 (has links)
Made available in DSpace on 2016-06-02T19:51:42Z (GMT). No. of bitstreams: 1 DissJFPJ.pdf: 724498 bytes, checksum: 72058d90b6e1572903d553ad3e5d24af (MD5) Previous issue date: 2004-02-26 / Initially this work explains, appraises and characterizes industrial cluster in the following classes: (C1) they are the Regional Cluster without formal coordenation that many authors call by Industrial Districts; (C2) class is about the clusters for Exportation e (C3) is about the Cluster Commanded by a Mother-company. The first class has been widely studied in literature. The group of research PLACOP of the Department of Production Engineering at Federal University in São Carlos has been developed research directed toward the classes C2 and C3. It is made a literature review on disturbance in the productive capacity once these factors are ones of the main problems of the current productive system; it is appraised change and disturbance, analyzed the impact of the disturbance and considered the classification of the types of disturbance in the productive capacity. After this it is briefly revised the problem of resource allocation. Later the problem of order allocation in industrial cluster in function of great disturbance in the production is studied, contemplating the definition of the problem with proposal of process of order allocation, the construction of the model and the use of the language of Modeling GAMS to get the results of the model. Finally a case study is presented that deepens the problem of disturbance in the productive capacity and order allocation in industrial cluster of the shoes´s sector of Birigüi (SP) commanded by a mother- company; in this case, the data are collected, the results are obtained and analysed. Since this research explore an aspect important and neglected by the Operations Management literature, this research brings a contribution for this knowledge area. / Esse trabalho inicia-se contextualizando, conceituando e caracterizando aglomerados industriais nas seguintes classes: (C1) são os Aglomerados Regionais sem coordenação formal que muitos autores denominam de Distritos Industriais; (C2) tratam-se dos Consórcios para Exportação e (C3) tratam-se dos Aglomerados Comandados por Empresa-mãe. A primeira classe tem sido amplamente estudada na literatura. O grupo de pesquisa PLACOP do Departamento de Engenharia de Produção da Universidade Federal de São Carlos vem desenvolvendo pesquisas voltadas para as classes C2 e C3. É feita uma revisão literária sobre distúrbios na capacidade produtiva uma vez que esses fatores são uns dos principais problemas do sistema produtivo atual, conceituando mudança e distúrbios, analisando o impacto dos distúrbios e propondo a classificação dos tipos de distúrbios na capacidade produtiva. A seguir é revisado de forma sucinta o problema de alocação de recursos. Depois é estudado o problema de alocação de pedidos em aglomerados industriais em função de grandes distúrbios na produção, contemplando a definição do problema com proposta de processo de alocação de pedidos, a construção do modelo e o uso da linguagem de Modelagem GAMS para obter os resultados do modelo. Por fim é apresentado um estudo de caso que aprofunda o problema de distúrbios na capacidade produtiva e de alocação de pedidos em um aglomerado industrial do setor calçadista de Birigüi (SP) comandada pela empresa-mãe, com levantamento dos dados, obtenção dos resultados e avaliação dos resultados de forma a proporcionar uma contribuição para a área de Gestão da Produção, pois explora um aspecto importante e pouco explorado formalmente.
12

Rearing programmes for breeding rabbits. Effect of early development and feeding on future reproductive performance of rabbit females and males

Martínez Paredes, Eugenio Melchor 02 September 2019 (has links)
[ES] Cualquier mejora en el conocimiento de la nutrición y el manejo de los futuros conejos reproductores debe considerarse como prioritario en la producción cunícola. Sin embargo, los principales esfuerzos en investigación se han centrado en estos animales durante la fase de reproducción propiamente dicha. La hipótesis inicial de esta tesis fue que alcanzar un desarrollo temprano adecuado durante la gestación, lactancia, engorde y recría, con la ayuda de programas ajustados de alimentación en algunos de estos períodos, mejoraría el rendimiento reproductivo y la vida útil de los futuros conejos reproductores. Para evaluar esta hipótesis, se llevaron a cabo dos tipos de ensayos, tanto en conejos hembra de líneas maternas como en machos de líneas seleccionadas por velocidad de crecimiento y destinadas a la inseminación artificial. El primero de estos ensayos se centró en los diferentes patrones de crecimiento, desde el nacimiento hasta el final de la fase de recría, y su influencia en la carrera reproductiva y la vida útil del conejo. En el segundo tipo de pruebas, se evaluó el efecto del uso de diferentes dietas o programas de alimentación durante el período de recría en la productividad a corto y medio plazo. Los resultados muestran dos fases importantes en el desarrollo temprano, de acuerdo con sus efectos sobre el rendimiento reproductivo y la vida útil. Mostrar un mayor desarrollo corporal desde el nacimiento hasta los 63 días de vida parece tener una influencia positiva en el grado de madurez y la productividad al comienzo de su vida reproductiva, además de poder mejorar su supervivencia a corto plazo, pero con posibles efectos negativos en la esperanza de vida a largo plazo. Sin embargo, el desarrollo durante el período de recría (desde los 63 días de vida hasta el comienzo de la carrera reproductiva) parece tener un mayor impacto en la productividad y la esperanza de vida de nuestros futuros conejos reproductores. Las hembras más engrasadas en la primera inseminación tuvieron tamaños de camada más pequeños y un mayor riesgo de ser sacrificadas que las magras (P<0.05). Además, los machos que mostraron una mayor ganancia media diaria durante el período de recría tuvieron un número y porcentaje de eyaculados viables más bajos a lo largo de su vida productiva y mayor riesgo de muerte o sacrificio. Estos resultados podrían indicar que la clave para llevar a cabo un desarrollo adecuado durante el período de recría debería basarse tanto en conseguir que los conejos alcancen un grado de madurez apropiado, tanto fisiológica como reproductivamente, así como evitar un excesivo engrasamiento al inicio de su vida productiva. En los ensayos destinados a evaluar los programas de alimentación durante la recría, el uso de una restricción alimentaria en hembras, y especialmente el uso de dietas fibrosas (de 8.5 a 10 MJ ED/kg MS) permiten un desarrollo corporal gradual y adecuado a la edad de cubrición, con suficientes reservas corporales para afrontar el comienzo de la vida reproductiva y mejorando tanto su rendimiento reproductivo como su vida útil. El éxito de estos programas de alimentación de recría depende del momento y la duración de la aplicación de estos, mejorándose con la aplicación de un cambio a un pienso enriquecido energéticamente alrededor del primer apareamiento. En los machos, se observó que un programa de alimentación durante la recría adecuado debería adaptarse a la capacidad de ingesta de estos y a sus necesidades nutricionales en períodos concretos de la recría, consiguiendo así mejoras en algunos parámetros del semen al inicio de su vida reproductiva. En conclusión, tanto un desarrollo temprano adecuado desde la gestación hasta el comienzo de su vida reproductiva, como el uso de programas adecuados de alimentación durante la recría podrían mejorar significativamente el rendimiento reproductivo futuro, así como la esperanza de vida, tanto en conejos he / [CAT] Qualsevol millora en el coneixement tant de la nutrició com del maneig dels futurs conills de criança ha de considerar-se com a prioritari en la producció de conills. No obstant açò, els principals esforços en investigació s'han centrat en aquests animals durant la fase de reproducció pròpiament dita. La hipòtesi inicial d'aquesta tesi va ser que aconseguir un desenvolupament primerenc adequat durant la gestació, lactància, engreix i criança, amb l'ajuda de programes ajustats d'alimentació en alguns d'aquests períodes, milloraria el rendiment reproductiu i la vida útil dels futurs conills reproductors. Per a avaluar aquesta hipòtesi, es van dur a terme dos tipus d'assajos, tant en conills femella de línies maternes, com en mascles de línies seleccionades per a la velocitat de creixement i destinades a la inseminació artificial. El primer d'aquests assajos es va centrar en els diferents patrons de creixement, des del naixement fins al final de la fase de criança, i la seua influència en la carrera reproductiva i la vida útil del conill. En el segon tipus de proves, es va avaluar l'efecte de l'ús de diferents dietes o programes d'alimentació durant el període de criança, en la productivitat a curt i mig termini. Els resultats obtinguts semblen indicar que podríem diferenciar dues fases en el desenvolupament primerenc, d'acord amb els seus efectes sobre el rendiment reproductiu i la vida útil. Mostrar un major desenvolupament corporal des del naixement fins als 63 dies de vida sembla tenir una influència positiva en el grau de maduresa i la productivitat al començament de la seua vida reproductiva, a més de poder millorar la seua supervivència a curt termini, però amb possibles efectes negatius en l'esperança de vida a llarg termini. No obstant açò, el desenvolupament durant el període de sembla tenir un major impacte en la productivitat i l'esperança de vida dels nostres futurs conills reproductors. Les femelles més greixades en la primera inseminació van tenir grandàries de ventrada més xicotets (tant nascuts com deslletats) i un major risc de ser sacrificades que les magres (P<0.05). A més, els mascles que van mostrar un major guany mitjà diari durant el període de criança van tenir un nombre i percentatge d'ejaculats viables més baixos al llarg de la seua vida productiva i major risc de mort o sacrifici. Aquests resultats podrien indicar que la clau per a dur a terme un desenvolupament adequat durant el període de criança hauria de basar-se tant a aconseguir que els conills aconseguisquen un grau de maduresa apropiat, per a afrontar els futurs desafiaments productius, com evitar un excessiu greixatge a l'inici de la seua vida productiva. En els assajos destinats a avaluar els programes d'alimentació durant la criança, l'ús d'una restricció alimentària en femelles, i especialment l'ús de dietes fibroses (de 8.5 a 10 MJ ED/kg MS) permeten un desenvolupament corporal gradual i adequat a l'edat de cobriment, amb suficients reserves corporals per a afrontar el començament de la vida reproductiva i millorant tant el seu rendiment reproductiu com la seua vida útil. L'èxit d'aquests programes d'alimentació de criança depèn del moment i la durada de l'aplicació d'aquests, millorant-se amb l'aplicació d'un canvi a un pinso enriquit energèticament al voltant del primer cobriment. En els mascles, es va observar que un programa d'alimentació durant la criança adequat hauria d'adaptar-se a la capacitat d'ingesta d'aquests i a les seues necessitats nutricionals en períodes concrets de la criança, aconseguint així millores en alguns paràmetres del semen a l'inici de la seua vida reproductiva. En conclusió, tant un desenvolupament primerenc adequat des de la gestació fins al començament de la seua vida reproductiva, com l'ús de programes adequats d'alimentació durant la criança podrien millorar significativament el rendiment reproductiu futur, així com l'esperança / [EN] Any improvement on the knowledge of both nutrition and management of the future rabbit breeders should be considered as crucial. However, main research efforts have been focused on animals during reproduction phase. The initial hypothesis of this thesis was that achieving an adequate early development during young rabbits' gestation, lactation, fattening and rearing, with the help of fitted feeding programmes in some of these periods, would be improved reproductive performance and lifespan of the future breeding rabbits. To evaluate this hypothesis, two types of trials, both in rabbit females from maternal lines selected for litter size at weaning and males from paternal lines selected for growth rate and intended on artificial insemination, were carried out. The first of these trials were mainly focused on the different growth patterns, from birth to the end of the rearing age, and their influence on rabbit's reproductive career and lifespan. In a second type of trials, the effect of the use of different diets or feeding programs during the rearing period in the performance in the short- medium-term was evaluated. The results obtained from the evaluation of the different growth patterns trials seem to indicate that, we could differentiate two parts on the early development according to their effects on reproductive performance and lifespan. To show a greater body development from birth to 63 days of life seems to have a positive influence on the maturity degree and productivity at the beginning of their reproductive life, as well as being able to improve their survival in the short-term, but it could be even negative for long-term lifespan. However, the development during the rearing period (from 63 days of life to the beginning of reproduction career) seems to have a higher impact on the productivity and lifespan of our rabbit breeders. Fatter rabbit females at first insemination had smaller litter sizes (born and weaned) and a higher risk of being culled (+13% per positive change in mm of perirenal fat) than lean ones (P<0.05). Also, rabbit males that showed a greater average daily gain during rearing period had a lower number and percentage of profitable ejaculates through it productive life (-10.1 and -4.9% per each 10 g of daily gain increase, respectively; P<0.05) and higher risk of death or culling (+16.2% per each increase in one standard deviation unit on live weight; P<0.05). These results could indicate that the key to carrying out an adequate development during the rearing period should allow the rabbits to reach an appropriate degree of physiological and reproductive maturity to face the future productive challenges, avoiding an excessive fatness at the beginning of their productive life. The use of a feeding restriction in rabbit females, and especially the use of fibrous diets (from 8.5 to 10 MJ DE/ kg DM) lead a gradual and adequate body development at mating, with enough body reserves to face the beginning of reproduction life and improving their whole reproductive performance and lifespan. The success of these rearing feeding programs depends in the moment and duration of application of them and improved with the application of a nutritional flushing around first mating. In rabbit males, it was observed that an adequate rearing feeding program should adapt it to the male's intake capacity and their nutritional requirements rearing period, especially to their high DP needs at the beginning of rearing period or when their requirements were close to maintenance, to improve some semen parameters at the beginning of their reproduction life. In conclusion, both the adequate early development of future rabbit breeders, from their own gestation to the beginning of their reproductive life, and the use of appropriate rearing feeding programs could significantly improve their future reproductive performance, as well as their life expectancy, both in rabbit females and males. / Martínez Paredes, EM. (2019). Rearing programmes for breeding rabbits. Effect of early development and feeding on future reproductive performance of rabbit females and males [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/124969 / TESIS
13

DEPENDABLE CLOUD RESOURCES FOR BIG-DATA BATCH PROCESSING & STREAMING FRAMEWORKS

Bara M Abusalah (10692924) 07 May 2021 (has links)
The examiner of cloud computing systems in the last few years observes that there is a trend of the emergence of new Big Data frameworks every single year. Since Hadoop was developed in 2007, new frameworks followed it such as Spark, Storm, Heron, Apex, Flink, Samza, Kafka ... etc. Each framework is developed in a certain way to target and achieve certain objectives better than other frameworks do. However, there are few common functionalities and aspects that are shared between these frameworks. One vital aspect all these frameworks strive to achieve is better reliability and faster recovery time in case of failures. Despite all the advances in making datacenters dependable, failures actually still happen. This is particularly onerous for long-running “big data” applications, where partial failures can lead to significant losses and lengthy recomputations. This is also crucial for streaming systems where events are processed and monitored online in real time, and any delay in data delivery will cause a major inconvenience to the users.<div>Another observation is that some reliability implementations are redundant between different frameworks. Big data processing frameworks like Hadoop MapReduce include fault tolerance mechanisms, but these are commonly targeted at specific system/failure models, and are often redundant between frameworks. Encapsulating these implementations into one layer and making it shared between different applications will benefit more than one frame-work without the burden of re-implementing the same reliability approach in each single framework.<br></div><div>These observations motivated us to solve the problem by presenting two systems: Guardian and Warden. Guardian is tailored towards batch processing big data systems while Warden is targeted towards stream processing systems. Both systems are robust, RMS based, generic, multi-framework, flexible, customizable, low overhead systems that allow their users to run their applications with individually configurable fault tolerance granularity and degree, with only minor changes to their implementation.<br></div><div>Most reliability approaches carry out one rigid fault tolerance technique targeted towards one system at a time. It is more challenging to provide a reliability approach that is pluggable in multiple Big Data frameworks at a time and can achieve low overheads comparable with single targeted framework approaches, yet is flexible and customizable by its users to make it tailored towards their objectives. The genericity is attained by providing an interface that can be used in different applications from different frameworks in any part of the application code. The low overhead is achieved by providing faster application finish times with and without failures. The customizability is fulfilled by providing the users the options to choose between two fault tolerance guarantees (Crash Failures / Byzantine Failures) and, in case of streaming systems; it is combined with two delivery semantics (Exactly Once / At Most Once).<br></div><div>In other words, this thesis proposes the paradigm of dependable resources: big data processing frameworks are typically built on top of resource management systems (RMSs),and proposing fault tolerance support at the level of such an RMS yields generic fault tolerance mechanisms, which can be provided with low overhead by leveraging constraints on resources.<br></div><div>To the best of our knowledge, such approach was never tried on multiple big data batch processing and streaming frameworks before.<br></div><div>We demonstrate the benefits of Guardian by evaluating some batch processing frame-works such as Hadoop, Tez, Spark and Pig on a prototype of Guardian running on Amazon-EC2, improving completion time by around 68% in the presence of failures, while maintaining around 6% overhead. We’ve also built a prototype of Warden on the Flink and Samza (with Kafka) streaming frameworks. Our evaluations on Warden highlight the effectiveness of our approach in the presence of failures and without failures compared to other fault tolerance techniques (such as checkpointing)<br></div>
14

Performance and Cost Optimization for Distributed Cloud-native Systems

Ashraf Y Mahgoub (13169517) 28 July 2022 (has links)
<p> First, NoSQL data-stores provide a set of features that is demanded by high perfor?mance computing (HPC) applications such as scalability, availability and schema flexibility. High performance computing (HPC) applications, such as metagenomics and other big data systems, need to store and analyze huge volumes of semi-structured data. Such applica?tions often rely on NoSQL-based datastores, and optimizing these databases is a challenging endeavor, with over 50 configuration parameters in Cassandra alone. As the application executes, database workloads can change rapidly over time (e.g. from read-heavy to write-heavy), and a system tuned for one phase of the workload becomes suboptimal when the workload changes. </p>
15

Cooperative Water Resources Allocation among Competing Users

Wang, Lizhong January 2005 (has links)
A comprehensive model named the Cooperative Water Allocation Model (CWAM) is developed for modeling equitable and efficient water allocation among competing users at the basin scale, based on a multiperiod node-link river basin network. The model integrates water rights allocation, efficient water allocation and equitable income distribution subject to hydrologic constraints comprising both water quantity and quality considerations. CWAM allocates water resources in two steps: initial water rights are firstly allocated to water uses based on legal rights systems or agreements, and then water is reallocated to achieve efficient use of water through water transfers. The associated net benefits of stakeholders participating in a coalition are allocated by using cooperative game theoretical approaches. <br /><br /> The first phase of the CWAM methodology includes three methods for deriving initial water rights allocation among competing water uses, namely the priority-based multiperiod maximal network flow (PMMNF) programming, modified riparian water rights allocation (MRWRA) and lexicographic minimax water shortage ratios (LMWSR) methods. PMMNF is a very flexible approach and is applicable under prior, riparian and public water rights systems with priorities determined by different criteria. MRWRA is essentially a special form of PMMNF adapted for allocation under the riparian regime. LMWSR is designed for application under a public water rights system, which adopts the lexicographic minimax fairness concept. The second step comprises three sub-models: the irrigation water planning model (IWPM) is a model for deriving benefit functions of irrigation water; the hydrologic-economic river basin model (HERBM) is the core component of the coalition analysis, which searches for the values of various coalitions of stakeholders and corresponding optimal water allocation schemes, based on initial water rights, monthly net benefit functions of demand sites and the ownership of water uses; the sub-model cooperative reallocation game (CRG) of the net benefit of the grand coalition adopts cooperative game solution concepts, including the nucleolus, weak nucleolus, proportional nucleolus, normalized nucleolus and Shapley value, to perform equitable reallocation of the net benefits of stakeholders participating in the grand coalition. The economically efficient use of water under the grand coalition is achieved through water transfers based on initial water rights. <br /><br /> Sequential and iterative solution algorithms utilizing the primal simplex method are developed to solve the linear PMMNF and LMWSR problems, respectively, which only include linear water quantity constraints. Algorithms for nonlinear PMMNF and LMWSR problems adopt a two-stage approach, which allow nonlinear reservoir area- and elevation-storage relations, and may include nonlinear water quality constraints. In the first stage, the corresponding linear problems, excluding nonlinear constraints, are solved by a sequential or iterative algorithm. The global optimal solution obtained by the linear programming is then combined together with estimated initial values of pollutant concentrations to be used as the starting point for the sequential or iterative nonlinear programs of the nonlinear PMMNF or LMWSR problem. As HERBM adopts constant price-elasticity water demand functions to derive the net benefit functions of municipal and industrial demand sites and hydropower stations, and quadratic gross benefit functions to find the net benefit functions of agriculture water uses, stream flow demands and reservoir storages, it is a large scale nonlinear optimization problem even when the water quality constraints are not included. An efficient algorithm is built for coalition analysis, utilizing a combination of the multistart global optimization technique and gradient-based nonlinear programming method to solve a HERBM for each possible coalition. <br /><br /> Throughout the study, both the feasibility and the effectiveness of incorporating equity concepts into conventional economic optimal water resources management modeling are addressed. The applications of CWAM to the Amu Darya River Basin in Central Asia and the South Saskatchewan River Basin in western Canada demonstrate the applicability of the model. It is argued that CWAM can be utilized as a tool for promoting the understanding and cooperation of water users to achieve maximum welfare in a river basin and minimize the damage caused by water shortages, through water rights allocation, and water and net benefit transfers among water users under the regulated water market or administrative allocation mechanism.
16

Cooperative Water Resources Allocation among Competing Users

Wang, Lizhong January 2005 (has links)
A comprehensive model named the Cooperative Water Allocation Model (CWAM) is developed for modeling equitable and efficient water allocation among competing users at the basin scale, based on a multiperiod node-link river basin network. The model integrates water rights allocation, efficient water allocation and equitable income distribution subject to hydrologic constraints comprising both water quantity and quality considerations. CWAM allocates water resources in two steps: initial water rights are firstly allocated to water uses based on legal rights systems or agreements, and then water is reallocated to achieve efficient use of water through water transfers. The associated net benefits of stakeholders participating in a coalition are allocated by using cooperative game theoretical approaches. <br /><br /> The first phase of the CWAM methodology includes three methods for deriving initial water rights allocation among competing water uses, namely the priority-based multiperiod maximal network flow (PMMNF) programming, modified riparian water rights allocation (MRWRA) and lexicographic minimax water shortage ratios (LMWSR) methods. PMMNF is a very flexible approach and is applicable under prior, riparian and public water rights systems with priorities determined by different criteria. MRWRA is essentially a special form of PMMNF adapted for allocation under the riparian regime. LMWSR is designed for application under a public water rights system, which adopts the lexicographic minimax fairness concept. The second step comprises three sub-models: the irrigation water planning model (IWPM) is a model for deriving benefit functions of irrigation water; the hydrologic-economic river basin model (HERBM) is the core component of the coalition analysis, which searches for the values of various coalitions of stakeholders and corresponding optimal water allocation schemes, based on initial water rights, monthly net benefit functions of demand sites and the ownership of water uses; the sub-model cooperative reallocation game (CRG) of the net benefit of the grand coalition adopts cooperative game solution concepts, including the nucleolus, weak nucleolus, proportional nucleolus, normalized nucleolus and Shapley value, to perform equitable reallocation of the net benefits of stakeholders participating in the grand coalition. The economically efficient use of water under the grand coalition is achieved through water transfers based on initial water rights. <br /><br /> Sequential and iterative solution algorithms utilizing the primal simplex method are developed to solve the linear PMMNF and LMWSR problems, respectively, which only include linear water quantity constraints. Algorithms for nonlinear PMMNF and LMWSR problems adopt a two-stage approach, which allow nonlinear reservoir area- and elevation-storage relations, and may include nonlinear water quality constraints. In the first stage, the corresponding linear problems, excluding nonlinear constraints, are solved by a sequential or iterative algorithm. The global optimal solution obtained by the linear programming is then combined together with estimated initial values of pollutant concentrations to be used as the starting point for the sequential or iterative nonlinear programs of the nonlinear PMMNF or LMWSR problem. As HERBM adopts constant price-elasticity water demand functions to derive the net benefit functions of municipal and industrial demand sites and hydropower stations, and quadratic gross benefit functions to find the net benefit functions of agriculture water uses, stream flow demands and reservoir storages, it is a large scale nonlinear optimization problem even when the water quality constraints are not included. An efficient algorithm is built for coalition analysis, utilizing a combination of the multistart global optimization technique and gradient-based nonlinear programming method to solve a HERBM for each possible coalition. <br /><br /> Throughout the study, both the feasibility and the effectiveness of incorporating equity concepts into conventional economic optimal water resources management modeling are addressed. The applications of CWAM to the Amu Darya River Basin in Central Asia and the South Saskatchewan River Basin in western Canada demonstrate the applicability of the model. It is argued that CWAM can be utilized as a tool for promoting the understanding and cooperation of water users to achieve maximum welfare in a river basin and minimize the damage caused by water shortages, through water rights allocation, and water and net benefit transfers among water users under the regulated water market or administrative allocation mechanism.
17

Δυναμική ανάθεση υπολογιστικών πόρων και συ-ντονισμός εκτέλεσης πολύπλοκων διαδικασιών ανάλυσης δεδομένων σε υποδομή Cloud / Dynamic allocation of computational resources and workflow orchestration for data analysis in the Cloud

Σφήκα, Νίκη 10 June 2015 (has links)
Το Υπολογιστικό Νέφος (Cloud Computing) χαρακτηρίζεται ως το νέο μοντέλο ανάπτυξης λογισμικού και παροχής υπηρεσιών στον τομέα των Τεχνολογιών Πληροφορικής και Επικοινωνιών. Τα κύρια χαρακτηριστικά του είναι η κατά απαίτηση διάθεση υπολογιστικών πόρων, η απομακρυσμένη πρόσβαση σε αυτούς μέσω διαδικτύου και η ευελιξία των παρεχόμενων υπηρεσιών. Η ευελιξία επιτρέπει την αναβάθμιση ή υποβάθμιση των υπολογιστικών πόρων σύμφωνα με τις απαιτήσεις του τελικού χρήστη. Επιπλέον, η συνεχής αύξηση του μεγέθους της παραγόμενης από διάφορες πηγές πληροφορίας (διαδίκτυο, επιστημονικά πειράματα) έχει δημιουργήσει μία τεράστια ποσότητα πολύπλοκων και διάχυτων ψηφιακών δεδομένων . Η απόσπαση χρήσιμης γνώσης από μεγάλου όγκου ψηφιακά δεδομένα απαιτεί έξυπνες και ευκόλως επεκτάσιμες υπηρεσίες ανάλυσης, εργαλεία προγραμματισμού και εφαρμογές. Επομένως, η δυνατότητα της ελαστικότητας και της επεκτασιμότητας έχει κάνει το Υ-πολογιστικό Νέφος να είναι μια αναδυόμενη τεχνολογία αναφορικά με τις αναλύσεις μεγάλου όγκου δεδομένων οι οποίες απαιτούν παραλληλισμό, πολύπλοκες ροές ανάλυσης και υψηλό υπολογιστικό φόρτο εργασίας. Για την καλύτερη δυνατή διαχείριση πολύπλοκων αναλύσεων και ενορχήστρωση των απαιτούμενων διαδικασιών, είναι απαραίτητη η ένθεση ροών εργασιών. Μια ροή εργασίας είναι ένα οργανωμένο σύνολο ενεργειών που πρέπει να πραγματοποιηθούν για να επιτευχθεί μια εμπορική ή ερευνητική διεργασία, καθώς και οι μεταξύ τους εξαρτήσεις αφού κάθε ενέργεια αποτελείται από ορισμένα βήματα που πρέπει να εκτελεστούν σε συγκεκριμένη σειρά. Στην παρούσα μεταπτυχιακή διπλωματική εργασία δημιουργήθηκε ένα σύστημα για τη δυναμική διαχείριση των προσφερόμενων πόρων σε μια υποδομή Υπολογιστικού Νέφους και την εκτέλεση κατανεμημένων υλοποιήσεων υπολογιστικής ανάλυσης δεδομένων. Συγκεκριμένα, η εφαρμογή, αφού λάβει από το χρήστη τα δεδομένα εισόδου για την έναρξη μιας νέας διαδικασίας ανάλυσης, εξετάζει τα δεδομένα των επιστημονικών προβλημάτων καθώς και την πολυπλοκότητά τους και παρέχει δυναμικά και αυτόματα τους αντίστοιχους υπολογιστικούς πόρους για την εκτέλεση της αντίστοιχης λειτουργίας ανάλυσής τους. Επίσης, επιτρέπει την καταγραφή της ανάλυσης και αναθέτει τον συντονισμό της διαδικασίας σε αντίστοιχες ροές εργασιών ώστε να διευκολυνθεί η ενορχήστρωση των παρεχόμενων πόρων και η παρακολούθηση της εκτέλεσης της υπολογιστικής διαδικασίας. Η συγκεκριμένη μεταπτυχιακή εργασία, με τη χρήση τόσο των παρεχόμενων υπηρεσιών μιας υποδομής Υπολογιστικού Νέφους όσο και των δυνατοτήτων που παρέχουν οι ροές εργασιών στην διαχείριση των εργασιών, έχει σαν αποτέλεσμα να απλουστεύει την πρόσβαση, τον έλεγχο, την οργάνωση και την εκτέλεση πολύπλοκων και παράλληλων υλοποιήσεων ανάλυσης δεδομένων από την στιγμή εισαγωγής των δεδομένων από το χρήστη έως τον υπολογισμό του τελικού αποτελέσματος. Πιο αναλυτικά η διπλωματική εργασία επικεντρώθηκε στη πρόταση μιας ολοκληρωμένης λύσης για: 1. τη παροχή μιας εφαρμογής στην οποία ο χρήστης θα έχει τη δυνατότητα να εισάγεται και να ξεκινά μια σύνθετη ανάλυση δεδομένων, 2. τη δημιουργία της κατάλληλης υποδομής για τη δυναμική διάθεση πόρων από μια cloud υποδομή ανάλογα με τις ανάγκες του εκάστοτε προβλήματος και 3. την αυτοματοποιημένη εκτέλεση και συντονισμό της διαδικασίας της ανάλυσης με χρήση ροών εργασιών. Για την επικύρωση και αξιολόγηση της εφαρμογής, αναπτύχθηκε η πλατφόρμα IRaaS η οποία παρέχει στους χρήστες του τη δυνατότητα επίλυσης προβλημάτων πολλαπλών πεδίων / πολλαπλών φυσικών. Η πλατφόρμα IRaaS βασίστηκε πάνω στην προαναφερόμενη εφαρμογή για τη δυναμική ανάθεση υπολογιστικών πόρων και συντονισμός εκτέλεσης πολύπλοκων διαδικασιών ανάλυσης δεδομένων. Εκτελώντας μια σειρά αναλύσεων παρατηρήθηκε ότι η συγκεκριμένη εφαρμογή παρέχει καλύτερους χρόνους εκτέλεσης, μικρότερη δέσμευση υπολογιστικών πόρων και κατά συνέπεια μικρότερο κόστος για τις αναλύσεις. Η εγκατάσταση της πλατφόρμας IRaaS για την εκτέλεση των πειραμάτων έγινε στην υποδομή Υπολογιστικού Νέφους του εργαστηρίου Αναγνώρισης Προτύπων. Η υποδομή βασίστηκε στα λογισμικά XenServer και Cloudstack, τα οποία εγκαταστάθηκαν και παραμετροποιήθηκαν στα πλαίσια της παρούσας εργασίας. / Cloud Computing is the new software development and service providing model in the area of Information and Communication Technologies. The main aspects of Cloud Computing are the on-demand allocation of computational resources, the remote access to the latter via the Internet and the elasticity of the provided services. Elasticity provides the capability to scale the computational resources depending on the computational needs. The continuous proliferation of data warehouses, webpages, audio and video streams, tweets, and blogs is generating a massive amount of complex and pervasive digital data. Extracting useful knowledge from huge digital datasets requires smart and scalable analytics services, programming tools, and applications. Due to the aspects of elasticity and scalability, Cloud Computing has become an emerging technology regarding to big data analysis, which demands parallelization, complex workflow analysis and massive computational workload. In this respect, workflows have an important role in managing complex flows and orchestrating the required processes. A workflow is an orchestrated set of activities that are necessary in order to complete a commercial or scientific task, as well as any dependencies between these tasks, since each one of them can be further decomposed into finer tasks that need to be executed in a predefined order. In this thesis, a system is presented that dynamically allocates the available resources provided by a cloud infrastructure and orchestrates the execution of complex and distrib-uted data analysis on these allocated resources. In particular, the system calculates the required computational resources (memory and CPU) based on the size of the input data and on the available resources of the cloud infrastructure, concluding to allocate dynamically the most suitable resources. . Moreover, the application offers the ability to coordinate the distributed analysis process utilising workflows for the orchestration and monitoring of the different tasks of the computational flow execution. Taking advantage of the services provided by a cloud infrastructure as well as the functionality of workflows in task management, this thesis has resulted in simplifying access, control, coordination and execution of complex and parallel data analysis implementations from the moment that a user enters a set of input data to the computation of the final result. In this context, this thesis focuses on a comprehensive and integrated solution that: 1. provides an application, through which the user is able to log in and start a complex data analysis, 2. offers the necessary infrastructure for dynamically allocating the cloud resources of, based on the needs of the particular problem, and 3. executes and coordinates the analysis process automatically by leveraging workflows. In order to validate and evaluate the application, the IRaaS platform was developed, offering the ability of solving multi-domain/multi-physics problems. The IRaaS platform is based on the aforementioned system in order to enable the dynamic allocation of computational resources and to coordinate the execution of complex data analysis processes. By executing a series of experiments with different input data, we observed that the presented application resulted in improved execution times, better allocation of computational resources and, thus, lower cost. In order to perform experiments, the IRaaS platform was set up on the cloud infrastructure of Pattern Recognition laboratory. In the context of this thesis, a new infrastructure has been installed and parameterized based on XenServer as virtualization hypervisor and CloudStack platform for the creation of a private cloud infrastructure.
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Télécommunications domotiques efficaces en termes de consommation d’énergie. / Energy efficient Telecommunication for home Automation

Masmoudi, Raouia 01 December 2015 (has links)
Le spectre électromagnétique est une ressource limitée dont l'usage doit être optimisé. Plusieurs travaux actuels visent à améliorer l'utilisation des fréquences radio en exploitant les méthodes de traitement intelligent du signal : la radio cognitive. Cette thèse se place dans ce contexte. Concrètement, nous considérons un problème d'allocation conjointe de spectre et de puissance dans un système radio cognitif (CR) composé de plusieurs utilisateurs secondaires (SUs) et primaires (PUs). L'objectif est d'optimiser l'efficacité énergétique des SUs tout en garantissant des niveaux d'interférences maximales imposés par la présence des PUs. Nous analysons des métriques d'efficacité énergétique en utilisant un cadre unificateur basé sur des outils d'optimisation convexe multi-critères. Les métriquesque nous étudions sont : la maximisation de débit avec pénalité sur l'interférence créée, le ratio débit puissance totale et la minimisation de puissance sous contrainte de débit pour concevoir un système de communications efficace en termes de consommation. Nous approfondissons ensuite l'étude de la métrique de minimisation de puissances sous contraintes de débits minimaux aux SUs et d'interférences maximales aux PUs. Étant donné la nature opposée de ces contraintes, nous étudions d'abord la faisabilité du problème et nous proposons des conditions nécessaires et des conditions suffisantes pour l'existence d'une solution. Le défi principal réside dans la non-convexité du problème d'allocation conjointe de spectre et de puissance en raison du paramètre discret d'ordonnancement des SUs. Afin de surmonter ce challenge, nous utilisons une technique de relaxation de Lagrange pour résoudre un problème convexe. Nous prouvons que les solutions discrètes du problème relaxé sont les solutions du problème initial. Lorsqu'une solution existe, nous proposonsun algorithme itératif basé sur la méthode de sous-gradient pour calculer la solution optimale. Nous montrons que le scheduling optimal est plus efficace comparé avec d'autres allocations de spectre classiques (e.g. entrelacée, blockwise). Dans le cas particulier de deux bandes orthogonales et un SU unique, nous proposons une solution analytique qui ne nécessite pas d'algorithme itératif. / The radio spectrum is a limited resource which must be used in an optimal way. Recent works in the literature aim to improve the use of radio frequencies by exploiting intelligent techniques from signal processing, such as the cognitive radio paradigm. In this thesis, we study a joint spectrum scheduling and power allocation problem in a Cognitive Radio (CR) system composed of several secondary users (SUs) and primary users (PUs). The objective is to optimize the energy efficiency of the SUs while guaranteeing that the interference created to the PUs is kept below a maximum tolerated level. We analyze energy efficiency metrics in wireless communications using a common unifying framework based on convex multi-criteria optimization tools, which includes the three of the most popular energyefficiency metrics in the literature : weighted difference between overall achievable rate and power consumption, the ratio between the overall rate and consumed power and overall consumed power under minimum rate constraint. Then, we further focus on the study of the opportunistic power minimization problem over several orthogonal frequency bands under constraints on the minimum Quality of Service (QoS) and maximum interference to the PUs. Given the opposing nature of these constraints, we first study the feasibility of the problem and we provide sufficient conditions and necessary conditions that guarantee the existence of a solution. The main challenge lies in the non-convexity of the joint spectrum and power allocation problem due to the discrete spectrum scheduling parameter of SUs. To overcome this issue, we use a Lagrangian relaxation technique to solve a convexproblem. We prove that the discrete solutions of the relaxed problem are the solutions of the initial problem. When a solution exists, we propose an iterative algorithm based on subgradient method to compute an optimal solution. We show that the optimal scheduling is more efficient compared to other conventional spectrum allocations (e.g. interlaced, blockwise). In the particular case of two orthogonal bands and an unique SU, we provide an analytical solution that does not require an iterative algorithm.
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L’expérimentation stratégique du business model : proposition d’un cadre conceptuel et méthodologique / Strategic experimentation of business model : towards the proposition of a conceptual and methodological framework

Ammar, Oussama 30 November 2010 (has links)
Face un environnement complexe et hyper-compétitif, les firmes sont amenées à reconsidérer leur modèle de création de valeur. Leur réaction s’insère dans le cadre d’une réinvention voire innovation de leur Business Model (BM). Ceci passe indéniablement par une démarche d’expérimentation stratégique. Définie comme un processus par lequel les firmes explorent de nouvelles sources de revenus et testent de nouveaux concepts d’affaires, l’expérimentation stratégique s’associe à un outil de réinvention du BM qui intervient non seulement dans la création de nouveaux BM mais également dans la transformation de BM existants. Nous posons ainsi la question de savoir : Comment concevoir l’expérimentation stratégique des BM des entreprises ? Dans cette perspective, notre recherche vise à dresser un cadre conceptuel et méthodologique de l’expérimentation stratégique. Il s’agit de proposer aux entreprises une aide à la conception d’une méthodologie d’expérimentation de BM. Pour répondre à cette problématique, nous proposons de définir l’expérimentation stratégique comme une théorie combinée du changement en partant du modèle de Van de Ven et Poole (1995) sur les théories de changement et de développement organisationnel. Ceci permet de traduire les processus centraux de l’expérimentation stratégique et d’en saisir les dimensions clés. Dans le cadre d’une approche qualitative avec étude de cas, nous interrogeons trois profils d’acteurs sur leurs registres de conception et de pratique de l’expérimentation. Ensuite, nous élaborons via une analyse inter-profils un modèle générique d’expérimentation stratégique de BM qui s’articule autour de trois temps de l’expérimentation stratégique ; un temps de virtualisation, un temps d’actualisation et un temps d’itérations de processus de rationalisation et d’apprentissage. / In a hypercompetitive environment, firms are obliged to reconsider their revenue formula and to innovate consequently the way they create value and make profit. This lies at the heart of every company’s ability to experiment new Business Models (BM) and becomes a key step in the strategic thinking. Defined as a process by which firms explore new ways of doing business, strategic experimentation takes shape of series of trial and error changes pursued along various dimensions of strategy in an effort to identify and establish a viable basis for competing. Our research examines strategic experimentation as an effective tool for BM reinvention. It answers therefore to the main question of: How to conceive BM experimentation? In this way, we define strategic experimentation as a combined theory of change according to the model developed by Van de Ven and Poole (1995) to explain processes of organizational development and change. We aim at dressing a conceptual and methodological framework for strategic experimentation that would helps managers and academics to conceive and master the process of BM experimentation. Using a qualitative research methodology rooted in a case study approach, we achieved semi-structured interviews with three categories of actors implied in the process of BM experimentation. Our results demonstrate that BM experimentation is organized through four major processes which are exploration, formulation, resources allocation and identification which are articulated by a time of virtualization, a time of actualization, and a time of iterations based on learning and rationalization.
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Simulação e otimização para o problema integrado de alocação de recursos humanos especialistas e sequenciamento de tarefas em uma indústria criativa

Santos, André Luis Marques Ferreira dos 30 August 2017 (has links)
Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-01-24T20:53:58Z No. of bitstreams: 1 Andre Luis Marques Ferreira dos Santos.pdf: 3359520 bytes, checksum: 44628dce3b0bf9344584d99777736b0f (MD5) / Made available in DSpace on 2018-01-24T20:53:58Z (GMT). No. of bitstreams: 1 Andre Luis Marques Ferreira dos Santos.pdf: 3359520 bytes, checksum: 44628dce3b0bf9344584d99777736b0f (MD5) Previous issue date: 2017-08-30 / The internet has contributed to the appearance of new kinds of businesses, which require a peculiar scientific approach in order to enlarge the operational results of the said enterprises. This context gave rise to a new set of organizations, businesses focused on intellectual production, the so-called creative industries. One of the ways to assess these intellectual capital companies is the optimization of human resources time, also known as Human Resources Specialists (HRS). The optimization of HRS’ consists in identifying which resources must be allocated to each project and the order in which the given tasks must be undertaken. In literature, this subject is known as “integrated problem of resources allocation and task scheduling”, commonly studied in manufacture businesses as “job shop problem”, but there is very little reference of the subject in the context of creative industries. Based on this assumption, the goal of this piece of work is to apply heuristic techniques to solve the HRS allocation and task scheduling problems within creative industries in an integrated way. Therefore, the model developed herein becomes relevant to researches involving the use of intellectual capital. The mentioned model consists in representing, through computer simulations, the operation of a competitive intelligence department and, making use of heuristics, determine the best scenarios for system optimization. In other words, to identify which of those scenarios makes viable to perform all projects in the shortest time possible. This model was based in real data, collected in two years of thorough observation of a company, the study object of this work. The outcome was satisfactory and the proposed model has achieved its objective. / A Internet contribuiu para o surgimento de um novo tipo de organização, as indústrias criativas, empresas com negócios focados no capital intelectual, os quais podem ser avaliados por meio da otimização do tempo dos recursos humanos, também intitulado como, recursos humanos especialistas (RHE). A otimização dos RHE consiste em identificar quais os recursos devem ser alocados para cada projeto e em qual ordem as tarefas devem ser realizadas, tema conhecido na literatura como “problema integrado de alocação de recursos e sequenciamento de tarefas”, comumente estudado nas empresas de manufatura como job shop problem, mas com pouca referência no contexto das indústrias criativas. Partindo desse pressuposto o objetivo deste trabalho foi desenvolver um modelo de simulação e otimização computacional, para resolver de forma integrada o problema de alocação de RHE e sequenciamento de tarefas dentro de uma indústria criativa. Assim, este trabalho torna-se relevante para as pesquisas que envolvam o uso de capital intelectual. O modelo desenvolvido neste trabalho consiste em representar por meio de simulação computacional o funcionamento de um departamento de inteligência competitiva e determinar os melhores cenários para otimizar o sistema, ou seja, identificar quais cenários viabilizam realizar todos os projetos em um menor tempo possível. A parametrização do modelo foi realizada com base em informações reais, coletadas em dois anos de observações na empresa objeto de estudo desta pesquisa. Os resultados mostram que a utilização de métodos computacionais de otimização pode contribuir na tomada de decisão para minimizar o tempo de realização dos projetos e para identificar os pontos de ociosidade do sistema em ambientes dinâmicos.

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