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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.
51

[en] GOAL-BASED INVESTMENTS: A DYNAMIC STOCHASTIC PROGRAMMING APPROACH / [pt] POLÍTICA DE INVESTIMENTO ORIENTADA A OBJETIVO DE LONGO PRAZO

ANDRE FREDERICO MACIEL GUTIERREZ 13 June 2024 (has links)
[pt] O objetivo deste estudo é desenvolver uma política de investimentoque minimize a contribuição total necessária para atingir um objetivofinanceiro a longo prazo. Para atingir este objetivo, desenvolvemos umproblema de otimização multi-estágios que integra um modelo de Markovoculto para captar a dinâmica estocástica dos retornos dos ativos. Aocontrário dos modelos convencionais de otimização de carteiras, que sebaseiam em pressupostos irrealistas, a nossa abordagem baseia-se no quadrode investimentos orientado a objetivos, que proporciona uma solução maisprática e eficaz. Além disso, ao utilizar o modelo de Markov oculto no nossoprocesso de otimização, obtemos uma estimativa mais precisa da dinâmicados retornos dos ativos, o que se traduz numa melhor tomada de decisõesde investimento. Ao utilizar o nosso modelo, a contribuição necessária paraatingir um objetivo financeiro desejado é minimizada através de uma políticade investimento que tem em conta o estado atual da riqueza e as condiçõeseconomicas prevalecentes. / [en] The aim of this study is to develop an investment policy that minimizes the total contribution required to achieve a long-term financial objective. To achieve this goal, we developed a multi-stage optimization problem that integrates a Hidden Markov Model to capture the stochastic dynamics of asset returns. Unlike conventional portfolio optimization models which are based on unrealistic assumptions, our approach is based on the goal oriented investment framework which provides a more practical and effective solution. In addition, by using the Hidden Markov Model in our optimization process, we obtain a more accurate estimate of the dynamics of asset returns, which translates into better investment decision-making. By using our model, the contribution required to achieve a desired financial goal is minimized through an investment policy that considers current levels of wealth and prevailing economic conditions.
52

Combining Business Intelligence, Indicators, and the User Requirements Notation for Performance Monitoring

Johari Shirazi, Iman 26 November 2012 (has links)
Organizations use Business Intelligence (BI) systems to monitor how well they are meeting their goals and objectives. Yet, very often BI systems do not include clear models of the organization’s goals or of how to measure whether they are satisfied or not. Several researchers now attempt to integrate goal models into BI systems, but there are still major challenges related to how to get access to the BI data to populate the part of the goal model (often indicators) used to assess goal satisfaction. This thesis explores a new approach to integrate BI systems with goal models. In particular, it explores the integration of IBM Cognos Business Intelligence, a leading BI tool, with an Eclipse-based goal modeling tool named jUCMNav. jUCMNav is an open source graphical editor for the User Requirements Notation (URN), which includes the Use Case Map notation for scenarios and processes and the Goal-oriented Requirement Language for business objectives. URN was recently extended with the concept of Key Performance Indicator (KPI) to enable performance assessment and monitoring of business processes. In jUCMNav, KPIs are currently calculated or modified manually. The new integration proposed in this thesis maps these KPIs to report elements that are generated automatically by Cognos based on the model defined in jUCMNav at runtime, with minimum effort. We are using IBM Cognos Mashup Service, which includes web services that enable the retrieval of report elements at the most granular level. This transformation provides managers and analysts with useful goal-oriented and process-oriented monitoring views fed by just-in-time BI information. This new solution also automates retrieving data from Cognos servers, which helps reducing the high costs usually caused by the amount of manual work required otherwise. The novel approach presented in this thesis avoids manual report generation and minimizes any contract with respect to the location of manually created reports, hence leading to better usability and performance. The approach and its tool support are illustrated with an ongoing example, validated with a case study, and verified through testing.
53

Combining Business Intelligence, Indicators, and the User Requirements Notation for Performance Monitoring

Johari Shirazi, Iman 26 November 2012 (has links)
Organizations use Business Intelligence (BI) systems to monitor how well they are meeting their goals and objectives. Yet, very often BI systems do not include clear models of the organization’s goals or of how to measure whether they are satisfied or not. Several researchers now attempt to integrate goal models into BI systems, but there are still major challenges related to how to get access to the BI data to populate the part of the goal model (often indicators) used to assess goal satisfaction. This thesis explores a new approach to integrate BI systems with goal models. In particular, it explores the integration of IBM Cognos Business Intelligence, a leading BI tool, with an Eclipse-based goal modeling tool named jUCMNav. jUCMNav is an open source graphical editor for the User Requirements Notation (URN), which includes the Use Case Map notation for scenarios and processes and the Goal-oriented Requirement Language for business objectives. URN was recently extended with the concept of Key Performance Indicator (KPI) to enable performance assessment and monitoring of business processes. In jUCMNav, KPIs are currently calculated or modified manually. The new integration proposed in this thesis maps these KPIs to report elements that are generated automatically by Cognos based on the model defined in jUCMNav at runtime, with minimum effort. We are using IBM Cognos Mashup Service, which includes web services that enable the retrieval of report elements at the most granular level. This transformation provides managers and analysts with useful goal-oriented and process-oriented monitoring views fed by just-in-time BI information. This new solution also automates retrieving data from Cognos servers, which helps reducing the high costs usually caused by the amount of manual work required otherwise. The novel approach presented in this thesis avoids manual report generation and minimizes any contract with respect to the location of manually created reports, hence leading to better usability and performance. The approach and its tool support are illustrated with an ongoing example, validated with a case study, and verified through testing.
54

Combining Business Intelligence, Indicators, and the User Requirements Notation for Performance Monitoring

Johari Shirazi, Iman January 2012 (has links)
Organizations use Business Intelligence (BI) systems to monitor how well they are meeting their goals and objectives. Yet, very often BI systems do not include clear models of the organization’s goals or of how to measure whether they are satisfied or not. Several researchers now attempt to integrate goal models into BI systems, but there are still major challenges related to how to get access to the BI data to populate the part of the goal model (often indicators) used to assess goal satisfaction. This thesis explores a new approach to integrate BI systems with goal models. In particular, it explores the integration of IBM Cognos Business Intelligence, a leading BI tool, with an Eclipse-based goal modeling tool named jUCMNav. jUCMNav is an open source graphical editor for the User Requirements Notation (URN), which includes the Use Case Map notation for scenarios and processes and the Goal-oriented Requirement Language for business objectives. URN was recently extended with the concept of Key Performance Indicator (KPI) to enable performance assessment and monitoring of business processes. In jUCMNav, KPIs are currently calculated or modified manually. The new integration proposed in this thesis maps these KPIs to report elements that are generated automatically by Cognos based on the model defined in jUCMNav at runtime, with minimum effort. We are using IBM Cognos Mashup Service, which includes web services that enable the retrieval of report elements at the most granular level. This transformation provides managers and analysts with useful goal-oriented and process-oriented monitoring views fed by just-in-time BI information. This new solution also automates retrieving data from Cognos servers, which helps reducing the high costs usually caused by the amount of manual work required otherwise. The novel approach presented in this thesis avoids manual report generation and minimizes any contract with respect to the location of manually created reports, hence leading to better usability and performance. The approach and its tool support are illustrated with an ongoing example, validated with a case study, and verified through testing.
55

English as a medium of instruction: the relationship between motivation and English second language proficiency

Madileng, Mary Mmatsatsi 06 1900 (has links)
In order to research the limited English proficiency of First Year National Intermediate Certificate students at the Further Education and Training College of Ekurhuleni West, the researcher investigated various motivation variables, namely: * socio-psychological factors * learner factors * parental involvement and * contextual factors related to the influence of the school and classroom A review of literature and empirical research methods were used to this effect. The literature review revealed that instrumental and integrative motivation, self-determination and goal orientedness, parental support and school and classroom context factors contributed to the development of ESL proficiency. A motivation questionnaire and an English proficiency test were administered to the participants. The results indicated no significant relationship between the learner's level of ESL proficiency and motivation variables. These findings form the basis for recommending specific guidelines for possible directions for future research. / Linguistics / M.A. (Specialisation in Applied Linguistics)
56

"Miss Kathy"

Alexander, Jeffrey, 1982- 05 1900 (has links)
Miss Kathy is a documentary film that tells the story of Kathy Griffin-Grinan, a lead recovery coach for prostitution and human trafficking with the Harris County Sheriff’s Office. Her non-profit organization —We’ve Been There, Done That – works in conjunction with law-enforcement to offer the survivors of prostitution a chance at rehabilitation. With endless enthusiasm, she mentors survivors as they struggle to escape a destructive lifestyle. This film also explores the relationship between human trafficking and prostitution, while addressing issues of victimization and exploitation.
57

Goal-Oriented Adaptivity using Unconventional Error Representations / Adaptabilité ciblée basée sur des représentations d'erreur non classiques

Darrigrand, Vincent 01 September 2017 (has links)
Dans un contexte d'adaptabilité ciblée, l'erreur commise sur une quantité d'intérêt peut être représentée grâce aux erreurs globales des problèmes direct et adjoint. Cette représentation de l'erreur est majorée par la somme des indicateurs d'erreurs élémentaires. Ces derniers sont alors utilisés pour produire des raffinements de maillage optimaux. Dans ces travaux, nous proposons de représenter l’erreur du problème adjoint via un opérateur alternatif. L’avantage principal de notre approche est que lorsque l'on choisit correctement l'opérateur alternatif, la majoration correspondante de l'erreur à la quantité d'intérêt devient plus précise, pour autant l'adaptabilité issue de l'utilisation de ces nouveaux indicateurs s'en trouve améliorée. Ces représentations peuvent être employées pour concevoir des algorithmes adaptatifs en espace (h), en ordre d’approximation (p) ou les deux (hp), basés sur la norme d’énergie ou bien ciblés sur une quantité d'intérêt. Bien que la méthode puisse être appliquée à une large gamme de problèmes, nous nous concentrons tout d’abord sur des problèmes unidimensionnels (1D), comme le problème d’Helmholtz et le problème de convection-diffusion stationnaire à convection dominante. Les résultats numériques en 1D montrent que, pour les problèmes de propagation d'ondes, les avantages de notre méthode sont notoires lorsque l'on considère l'opérateur de Laplace pour la représentation de l'erreur. Plus précisément, les majorations issues de la nouvelle représentation sont plus précises que celles provenant de la méthode classique et ce si l'on considère l'énergie globale ou bien une quantité d'intérêt particulière. Le phénomène est d’autant plus notable lorsque l'erreur de dispersion (pollution) est significative. Le problème 1D de convection-diffusion stationnaire à convection dominante avec des conditions limites de Dirichlet homogènes présente une couche limite qui produit une perte de stabilité numérique. La nouvelle représentation d'erreur délivre des majorations plus précises. Lorsqu’appliquée à une p-adaptabilité ciblée, la représentation d'erreur alternative permet une capture plus efficace la couche limite, malgré les oscillations numériques parasites existantes. Devant ces résultats encourageants, nous nous penchons sur l'équation d'Helmholtz à deux et trois dimensions (2D et 3D). Nous montrons, au travers de multiples simulations numériques, que les majorations fournies par les représentations d'erreur alternatives sont plus précises que celle de la représentation classique. Lorsque l'on utilise les indicateurs d'erreur alternatifs, un processus naïf de p-adaptabilité ciblée converge, tandis que dans les mêmes conditions, la méthode classique échoue et requiert l'utilisation d'un opérateur de projection ou d'autre techniques pour récupérer la convergence. Dans ce travail, nous fournissons également des directives pour déterminer les opérateurs qui fournissent des représentations d’erreur induisant de majorations précises. Des résultats similaires sont aussi établis tant pour un problème 2D de convection-diffusion stationnaire à convection dominante que pour des problèmes 2D ayant des coefficients de matériaux discontinus. Nous considérons un problème de diagraphie ultra-sonique en cours de forage pour illustrer l'applicabilité de la méthode proposée. / In Goal-Oriented Adaptivity (GOA), the error in a Quantity of Interest (QoI) is represented using global error functions of the direct and adjoint problems. This error representation is subsequently bounded above by element-wise error indicators that are used to drive optimal refinements. In this work, we propose to replace, in the error representation, the adjoint problem by an alternative operator. The main advantage of the proposed approach is that, when judiciously selecting such alternative operator, the corresponding upper bound of the error representation becomes sharper, leading to a more efficient GOA. These representations can be employed to design novel h, p, and hp energy-norm and goal-oriented adaptive algorithms. While the method can be applied to a variety of problems, in this Dissertation we first focus on one-dimensional (1D) problems, including Helmholtz and steady state convection-dominated diffusion problems. Numerical results in 1D show that for the Helmholtz problem, it is advantageous to select the Laplace operator for the alternative error representation. Specifically, the upper bounds of the new error representation are sharper than the classical ones used in both energy-norm and goal-oriented adaptive methods, especially when the dispersion (pollution) error is significant. The 1D steady state convection-dominated diffusion problem with homogeneous Dirichlet boundary conditions exhibits a boundary layer that produces a loss of numerical stability. The new error representation based on the Laplace operator delivers sharper error upper bounds. When applied to a p-GOA, the alternative error representation captures earlier the boundary layer, despite the existing spurious numerical oscillations. We then focus on the two- and three-dimensional (2D and 3D) Helmholtz equation. We show via extensive numerical experimentation that the upper bounds provided by the alternative error representations are sharper than the classical ones. When using the alternative error indicators, a naive p-adaptive process converges, whereas under the same conditions, the classical method fails and requires the use of the so-called Projection Based Interpolation (PBI) operator or some other technique to regain convergence. We also provide guidelines for finding operators delivering sharp error representation upper bounds. / En un contexto de adaptatividad orientada a un objetivo, el error en una cantidad de interés está representado a través de los errores globales de los problemas directo y adjunto. Esta representación del error se acota superiormente por una suma de indicadores de error de cada elemento. Estos se utilizan para producir refinamientos óptimos. En este trabajo, proponemos representar el error del problema adjunto utilizando un operador alternativo. La principal ventaja de nuestro enfoque es que cuando se elige correctamente dicho operador alternativo, la correspondiente cota superior se vuelve más cercana al error en la cantidad de interés, lo que permite una adaptatividad más eficiente. Estas representaciones pueden ser utilizadas para diseñar algoritmos adaptativos en h, p o hp, basados en la norma de la energía o para aproximar una cantidad de interés específica. Aunque el método propuesto se puede aplicar a una amplia gama de problemas, en esta tesis doctoral nos centramos primero en problemas unidimensionales (1D), tales como el problema de Helmholtz y el problema estacionario de convección-difusión con convección dominante. Los resultados numéricos en 1D muestran que, para los problemas de propagación de ondas, las ventajas de este método son notorias cuando se considera el operador de Laplace para la representación del error. Específicamente, las cotas superiores derivadas de la nueva representación son más cercanas a la cantidad de interés que las del método convencional. Esto es cierto tanto para la norma de la energía global como para una cantidad de interés particular, especialmente cuando el error de dispersión es significativo. El problema estacionario 1D de convección-difusión con convección dominante y con condiciones de Dirichlet homogéneas tiene una capa límite que produce una pérdida de estabilidad numérica. La nueva representación del error proporciona cotas superiores más cercanas a la cantidad de interés. Cuando se aplica a un algoritmo adaptativo en p orientado a un objetivo, la representación alternativa del error captura antes la capa límite, a pesar de las existentes oscilaciones numéricas no físicas. En esta tesis doctoral, también nos centramos en la ecuación de Helmholtz en dos y tres dimensiones (2D y 3D). Mostramos a través de múltiples experimentos numéricos que las cotas superiores proporcionadas por las representaciones alternativas del error son más cercanas a la cantidad de interés que cuando uno considera la representación clásica. Al utilizar los indicadores alternativos del error, un algoritmo adaptativo en p sencillo converge, mientras que en las mismas condiciones, el método convencional falla y requiere el uso de operadores de proyección o de otras técnicas para recuperar la convergencia. En este trabajo, también determinamos operadores que proporcionan representaciones del error que inducen cotas superiores más ajustadas. Establecemos resultados similares tanto para el problema estacionario de convección-difusión con convección dominante en 2D como para problemas 2D con materiales discontinuos. Finalmente, se considera un problema sónico en pozos petrolíferos para ilustrar la aplicabilidad del método propuesto.
58

Det mångsidiga uppdraget : Fritidspedagoger som riktar sig mot skola såväl som fritidshem / The versatile assignment : Leisure-time educators aimed at both school and leisure-time

Molina, Enzo, Truedsson, Veronica January 2017 (has links)
Den historiska bakgrunden och tidigare forskningen kring vårt ämne pekar på en återkommande problematik inom fritidshemmet och fritidspedagogsyrket. Problematiken utgörs av en tvetydig syn på hur man ska tolka eller uppfatta det fritidspedagogiska uppdraget. Studiens syfte är därför att undersöka de målorienterade handlingar som utövas av fritidspedagoger i olika kontexter. Därmed utformar vi vår egna definition av uppdraget genom dessa målorienterade handlingar. Vi har valt att genomföra ett fältarbete av etnografisk karaktär som bygger på observationer som har ägt rum på en skola. Den här metoden anknyts till vår teori, Roger Säljös tolkning av den sociokulturella teorin, som utgår ifrån det praktiska som framträder genom kommunikativa och fysiska handlingar. Dessutom har vi genomfört informella samtal när vi har velat förtydliga fritidspedagogernas handlingar. Vår undersökning visar att fritidspedagogerna utövar ett mångsidigt uppdrag som beroende på situationen använder sig av fyra olika arbetssätt och därmed omväxlande riktar sig mot såväl skola som fritidshem. Vi uppfattar inte fritidspedagogernas uppdrag som tvetydigt, vilket den tidigare forskning vi tagit del av uppmärksammar, utan vårt resultat visar att fritidspedagogerna utövar ett tydligt uppdrag som både är målorienterat och mångsidigt. / The historical background and previous studies on our subject point to a recurrent problem in the leisure education sector. The problem consists of an ambiguous view of how the leisuretime educators should interpret or perceive their assignment. The purpose of the study is therefor to investigate the goal-oriented actions performed by leisure-time educators, in different contexts. Thus we develop our own definition of the assignment through these goaloriented actions. We have chosen to carry out a field work of ethnographic character based on observations that have taken place in a school. This method is linked to our theory, Roger Säljö's interpretation of socio-cultural theory, which is based on the practical that´s emerging through communicative and physical actions. Furthermore we have completed informal conversations when we have wished to clarify the leisure-time educator’s actions. Our study shows that the leisure-time educators execute a versatile assignment which, depending on the situation, uses four different ways of working. These approaches vary in terms of both school and leisure-time. We do not perceive the task of the leisure-time educators as ambiguous as previous studies have shown. Our results, on the other hand, show that leisure-time educators perform a clear assignment that is both goal-oriented and versatile.
59

Un robot curieux pour l’apprentissage actif par babillage d’objectifs : choisir de manière stratégique quoi, comment, quand et de qui apprendre / A Curious Robot Learner for Interactive Goal-Babbling : Strategically Choosing What, How, When and from Whom to Learn

Nguyen, Sao Mai 27 November 2013 (has links)
Les défis pour voir des robots opérant dans l’environnement de tous les jours des humains et sur unelongue durée soulignent l’importance de leur adaptation aux changements qui peuvent être imprévisiblesau moment de leur construction. Ils doivent être capable de savoir quelles parties échantillonner, et quelstypes de compétences il a intérêt à acquérir. Une manière de collecter des données est de décider par soi-même où explorer. Une autre manière est de se référer à un mentor. Nous appelons ces deux manièresde collecter des données des modes d’échantillonnage. Le premier mode d’échantillonnage correspondà des algorithmes développés dans la littérature pour automatiquement pousser l’agent vers des partiesintéressantes de l’environnement ou vers des types de compétences utiles. De tels algorithmes sont appelésdes algorithmes de curiosité artificielle ou motivation intrinsèque. Le deuxième mode correspond au guidagesocial ou l’imitation, où un partenaire humain indique où explorer et où ne pas explorer.Nous avons construit une architecture algorithmique intrinsèquement motivée pour apprendre commentproduire par ses actions des effets et conséquences variées. Il apprend de manière active et en ligne encollectant des données qu’il choisit en utilisant plusieurs modes d’échantillonnage. Au niveau du metaapprentissage, il apprend de manière active quelle stratégie d’échantillonnage est plus efficace pour améliorersa compétence et généraliser à partir de son expérience à un grand éventail d’effets. Par apprentissage parinteraction, il acquiert de multiples compétences de manière structurée, en découvrant par lui-même lesséquences développementale. / The challenges posed by robots operating in human environments on a daily basis and in the long-termpoint out the importance of adaptivity to changes which can be unforeseen at design time. The robot mustlearn continuously in an open-ended, non-stationary and high dimensional space. It must be able to knowwhich parts to sample and what kind of skills are interesting to learn. One way is to decide what to exploreby oneself. Another way is to refer to a mentor. We name these two ways of collecting data sampling modes.The first sampling mode correspond to algorithms developed in the literature in order to autonomously drivethe robot in interesting parts of the environment or useful kinds of skills. Such algorithms are called artificialcuriosity or intrinsic motivation algorithms. The second sampling mode correspond to social guidance orimitation where the teacher indicates where to explore as well as where not to explore. Starting fromthe study of the relationships between these two concurrent methods, we ended up building an algorithmicarchitecture with a hierarchical learning structure, called Socially Guided Intrinsic Motivation (SGIM).We have built an intrinsically motivated active learner which learns how its actions can produce variedconsequences or outcomes. It actively learns online by sampling data which it chooses by using severalsampling modes. On the meta-level, it actively learns which data collection strategy is most efficient forimproving its competence and generalising from its experience to a wide variety of outcomes. The interactivelearner thus learns multiple tasks in a structured manner, discovering by itself developmental sequences.
60

English as a medium of instruction: the relationship between motivation and English second language proficiency

Madileng, Mary Mmatsatsi 06 1900 (has links)
In order to research the limited English proficiency of First Year National Intermediate Certificate students at the Further Education and Training College of Ekurhuleni West, the researcher investigated various motivation variables, namely: * socio-psychological factors * learner factors * parental involvement and * contextual factors related to the influence of the school and classroom A review of literature and empirical research methods were used to this effect. The literature review revealed that instrumental and integrative motivation, self-determination and goal orientedness, parental support and school and classroom context factors contributed to the development of ESL proficiency. A motivation questionnaire and an English proficiency test were administered to the participants. The results indicated no significant relationship between the learner's level of ESL proficiency and motivation variables. These findings form the basis for recommending specific guidelines for possible directions for future research. / Linguistics and Modern Languages / M.A. (Specialisation in Applied Linguistics)

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