Haptic-based Virtual Reality (VR) applications have many merits. What is still obscure, from the designer’s perspective of these applications, is the experience the users will undergo when they use the VR system. Quality of Experience (QoE) is an evaluation metric from the user’s perspective that unfortunately has received limited attention from the research community. Assessing the QoE of VR applications reflects the amount of overall satisfaction and benefits gained from the application in addition to laying the foundation for ideal user-centric design in the future. In this thesis, we address certain issues and concerns regarding QoE of virtual environments. In essence, we propose a taxonomy for the evaluation of the QoE for multimedia applications and in particular VR applications. The taxonomy classifies QoE related parameters into groups. The groups’ organization is generated from the definition we have adopted for the QoE which is the Quality of Service (QoS) plus the user experience (UX). We model this taxonomy using first mathematical modeling based on weighted averages and then a Fuzzy logic Inference System (FIS) to quantitatively measure the QoE of haptic virtual environments. We test both models conducting user study analysis to evaluate the QoE of a VR application. These models serve as engines that facilitate the calculation of QoE with minimal amount of users. We specifically attend to the issue of the new media, haptics, within the context of increasing the QoE of virtual environments (VE). This special attention is important for comparing the effect of tactile and kinesthetic feedback on the QoE. In accordance, we investigate a particular topic that seems to have a colossal effect on QoE throughout our analysis, which is fatigue. Our analysis involved users' studies since the main focus is on the user. The QoE for virtual environments is in its primary stages. This thesis tackles issues that are vital in dealing with and understanding the importance of QoE. The various results suggest a positive user's disposition toward haptics and virtual environments, yet there will always be obstacles and challenges such as fatigue that if minimized will enhance the QoE of haptic-based applications.

The electric power sector is undergoing significant changes with the development of Smart Grid technologies and is rapidly influencing the way we consume energy. Demand Response (DR) is an important element in the emerging smart grid paradigm and is paving way for the more sophisticated implementation of Energy Hub Management Systems (EHMSs). Utilities are looking at Demand Side Management (DSM) and DR services that allow customers to make informed decisions regarding their energy consumption which in return, can help the energy providers to reduce their peak demand and hence enhance grid sustainability. Ice rinks are large commercial buildings which facilitate various activities such as hockey, figure skating, curling, recreational skating, public arenas, auditoriums and coliseums. These have a complex energy system; in which an enormous sheet of ice is maintained at a low temperature while at the same time the spectator stands are heated to ensure comfortable conditions for the spectators. Since indoor ice rinks account for a significant share of the commercial sector and are in operation for more than 8 months a year, their contribution in the total demand cannot be ignored. There is significant scope for energy savings in indoor ice rinks through optimal operation of their climate control systems. In this work, a mathematical model of indoor ice rinks for the implementation of EHMS is developed. The model incorporates weather forecast, electricity price information and end-user preferences as inputs and the objective is to shift the operation of climate control devices to the low electricity price periods, satisfying their operational constraints while having minimum impact on spectator comfort. The inside temperature and humidity dynamics of the spectator area are modeled to reduce total electrical energy costs while capturing the effect of climate control systems including radiant heating system, ventilation system and dehumidification system. Two different pricing schemes, Real Time Pricing (RTP) and Time-of-Use (TOU), are used to assess the model, and the resulting energy costs savings are compared. The expected energy cost savings are evaluated for a 8 month period of operation of the rink incorporating the uncertainties in electricity price, weather conditions and spectator schedules through Monte Carlo simulations. The proposed work can be implemented as a supervisory control in existing climate controllers of indoor ice rinks and would play a significant role in the enforcement of EHMS in Smart Grids.

This thesis presents models that describe the behaviour of electricity demand and ambient temperature. Important features of both variables are described by mathematical components. These models were developed to calculate the value of electricity demand that is not expected to be exceeded more than once in ten years and to generate synthetic sequences that can be used as input data in simulation software. / PhD Doctorate

在這篇論文當中，我們引用`海岸綠堤--水筆仔'網站上的研究資料並且藉由Matlab程式軟體的幫助建構數學模型，我們討論以下的二階非線性微分方程 (i) u''(t)=f(u(t)), u(t_0)=u_0, u'(t_0)=u_1. (ii) u''(t)=f(u'(t)), u(t_0)=u_0, u'(t_0)=u_1. 我們比較拋物線函數，立方函數，傅立葉和函數，正弦和函數並且從這些函數中選出最好的一個當作我們的模型，我們得到一些主要的結果。 / In this paper, we use the real data from website of `Seacoast Green Bank--Kandelia' and construct mathematical models with the help of Matlab, we discuss the following nonlinear 2nd order differential equation (i) u''(t)=f(u(t)), u(t_0)=u_0, u'(t_0)=u_1. (ii) u''(t)=f(u'(t)), u(t_0)=u_0, u'(t_0)=u_1. We compared with the functions of parabolic, cubic, Fourier summation, sum of sine and choose the best one from them as our model, we have obtained main results.

Neste trabalho procurou-se avaliar o processo de construção e aplicação de modelos preditivos no meio florestal. Para tanto, no primeiro artigo parte-se de uma amostra destrutiva de 200 indivíduos de dez espécies arbóreas distintas, originárias do bioma Atlântico, testando-se três modelos teóricos comumente usados na predição de volume e biomassa, sendo a esses adicionados preditores informativos da densidade básica da árvore. Para a avaliação os modelos ajustados foram simuladas três situações preditivas distintas. Os resultados demonstraram que aplicar o modelo em situações distintas a da amostra de ajuste gera viés nas predições que, no entanto, é reduzido com a entrada dos referidos preditores. O segundo artigo apresenta aplicações da calibração do modelo linear de efeito misto na predição do volume em plantios de Eucalyptus grandis em primeira e segunda rotação. Para tanto, partiu-se do modelo de Schumacher e Hall, em sua forma linearizada, para o desenvolvimento modelo de efeitos mistos, que considerou alguns de seus parâmetros como sendo aleatórios ao longo das diferentes fazendas. A calibração foi realizada em nível de fazenda partindo-se de um pequeno número de árvores-amostra. A abordagem foi desenvolvida para modelos univariados de primeira rotação, além de modelos bivariados de duas rotações. Os resultados mostraram que o procedimento de calibração fornece predições mais confiáveis que a dos modelos tradicionais de efeitos fixos em ambas as rotações. O terceiro artigo apresenta aplicações da calibração do modelo linear de efeito misto na predição da biomassa de árvores de espécies nativas numa floresta Ombrófila densa. Partiuse do modelo de potência, em sua forma linearizada, para o desenvolvimento modelo de efeitos mistos e dois níveis: parcela e espécie, O ajuste do modelo foi feito considerando esses dois níveis, mas a calibração foi realizada em cada nível ignorando o efeito do outro, nível. Os resultados mostraram que o procedimento de calibração fornece predições mais confiáveis em nível de espécie que os modelos tradicionais. Em nível de parcela, a calibração não foi efetiva. / In this study we tried to evaluate the process of construction and application of predictive models in forestry. Therefore, in the first paper we started from a destructive sample of 200 individuals from ten different tree species, originating from the Atlantic biome. We tested three theoretical models commonly used to predict volume and biomass, which was added predictors related to tree basic density. To evaluate the models were simulated three different predictive situations. The results showed that applying the model in different situations from the sample generates bias on predictions; however, it is reduced by adding the referred predictors. The second article presents applications of linear mixedeffects models and calibration to predict the volume in Eucalyptus grandis plantations in first and second rotation. Therefore, we started with the model of Schumacher and Hall, in their linearized form to develop the mixed-effects model, which considered some of its parameters as random throughout the different farms. The calibration was performed at the farm level and starting from a small number of sample trees. The approach was developed to first rotation univariate models, and a bivariate model of both rotations. The results showed that the calibration procedure provides more reliable predictions than the traditional fixed effects models in both rotations. The third article presents applications of linear mixedeffects model and calibration to predict the biomass in a rain forest. We started from the power model, in its linearized form, for developing the mixed-effects model considering two levels of grouping: plot and species, Model fitting was made considering these two levels, but the calibration was performed on each level ignoring the other level effect. The results showed that the calibration procedure provides more reliable predictions at species level than traditional models. On the plot level, the calibration was not effective.

The symbiosis between plants of the legume family and nitrogen-fixing rhizobia underpins global food security. Legume crops are a major source of protein in human diets, either directly or indirectly as feed for livestock. Application of inoculant rhizobial strains is common practice in many areas, as plant growth is often nitrogen limited and the symbiosis can significantly enhance yields. However, rhizobial strains and outcomes of the symbiosis vary widely. This variation has also been studied by evolutionary biologists interested in the stability of mutualisms. They proposed that plants may prevent establishing symbioses with ineffective strains (partner choice), or provide them with fewer resources (sanctioning). I studied both mechanisms, combining modelling and experimental approaches. Mathematical modelling was used to predict how plants should allocate resources to maximise growth rates, depending on rhizobial nitrogen provision and carbon requirements and on soil nitrogen conditions. The use of marked mutant strains – easily distinguishable and differing in a single rhizobial characteristic – overcame previous experimental difficulties. It was found that pea (Pisum sativum L.) plants are not able to exert partner choice, but do sanction in a more complex way than was previously established. In line with model predictions, resources were preferentially allocated to the single – best available – strain, so that resources allocated to an intermediate-fixing strain depended on whether or not a strain providing more nitrogen was available. Contrary to model predictions, there was no indication of discrimination based on rhizobial carbon requirements. The results cannot be explained by resource allocation in proportion to nitrogen received, and indicate systemic integration of information from different nodules. I formulate a hypothesis about the underlying plant regulatory mechanisms, and discuss implications of the results for selecting inoculant strains and enhancing yields in the field. Future work will rely on further integration of theoretical and applied methods and perspectives.

La thèse porte sur la proposition de méthodes d’optimisation (modèles mathématiques et métaheuristique) et leur couplage avec un modèle de simulation pour la résolution de problèmes de livraison collecte incluant la planification des horaires des chauffeurs. L’originalité de ces travaux porte sur la diversité des ressources (véhicule, chauffeur, quai de chargement, de déchargement, contenant, ligne de production, aire de nettoyage) et des contraintes (incompatibilité véhicule/contenant, date de début au plus tôt, date de fin souhaitée, planning…) à prendre en compte. L’objectif est de proposer une organisation permettant de réaliser l’ensemble des transports tout en minimisant les retards et les heures supplémentaires. La première partie s’intéresse au transport d’un seul type de produit. Le problème est modélisé comme un RCPSP avec profil de demande en ressources variable. Les transports à vide sont modélisés comme des temps de montage dépendant de la séquence. Deux programmes linéaires en nombres entiers sont proposés. La seconde partie concerne le transport de plusieurs types de produit. Le problème présente une double complexité qui est résolue par le couplage d’une recherche locale itérée avec un modèle de simulation. Le modèle de simulation permet de répondre à la complexité structurelle et fonctionnelle, notamment en raison de la diversité des ressources. La troisième partie intègre la définition des horaires de travail des chauffeurs. Une approche itérative incluant un modèle de simulation, un programme linéaire en nombres entiers et le couplage précédemment présenté est proposée. Ce problème est traité dans un contexte hospitalier pour le transport de contenants propres ou sales (repas, linge, médicaments) entre sites de consommation et sites de production. Chaque partie fait l’objet d’une expérimentation avec des données réelles. / The thesis focuses on the proposed optimization methods (metaheuristics and mathematical models) and their coupling with a simulation model to solve problems of collection including delivery scheduling drivers. The originality of this work focuses on the diversity of resources (vehicle, driver, dock loading, unloading, container production line, cleaning area) and constraints (incompatibility vehicle / container, start date earlier desired end date, planning ...) to take into account. The objective is to provide an organization to achieve all transport while minimizing delays and overtime. The first part focuses on the transport of a single type of product. The problem is modeled as a demand profile RCPSP with variable resources. Empty transports are modeled as time-dependent assembly sequence. Two integer linear programs are proposed. The second part concerns the transport of several types of product. The problem has a double complexity that is determined by the coupling of an iterated local search with a simulation model. The simulation model allows to meet the structural and functional complexity, mainly because of the diversity of resources. The third part includes the definition of working hours of drivers. An iterative approach including a simulation model, an integer linear program and previously presented coupling is proposed. This problem is treated in a hospital setting for transporting containers clean or dirty (food, clothes, medicine) between sites of consumption and production sites. Each party is subject to an experiment with real data.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-09-14T12:22:51Z No. of bitstreams: 1 JOSÉ RILDO DE OLIVEIRA - TESE (PPGEP) 2006.pdf: 1131201 bytes, checksum: ba0909f714e2920247098ffc14790d7d (MD5) / Made available in DSpace on 2018-09-14T12:22:51Z (GMT). No. of bitstreams: 1 JOSÉ RILDO DE OLIVEIRA - TESE (PPGEP) 2006.pdf: 1131201 bytes, checksum: ba0909f714e2920247098ffc14790d7d (MD5) Previous issue date: 2006 / Estudou-se o comportamento das propriedades físicas do feijão-macáçar ( Vigna unguiculata (l.) Walpers) - porosidade, área superficial, área específica, calor específico, massa especifica aparente e isotermas de equilíbrio -, com teor de água inicial de 20, 40 e 65 %, base úmida, os efeitos do teor de água inicial do produto, da temperatura e da velocidade do ar de secagem, sobre a cinética de secagem do produto. As isotermas de equilíbrio do feijão-macáçar com teor de água inicial de 65%, base úmida, foram determinadas pelo método estático, a temperaturas de 20, 30, 40 e 50 ºC, com umidade relativas variando de 0,10 a 0,85, decimal. Para análise dos dados experimentais, foram utilizados cinco modelos matemáticos: Henderson-Thompson; modelo de Henderson-Thompson modificado por Cavalcanti Mata; modelo de Chung- Pfost; modelo de Oswin modificado; modelo de Halsey modificado. O estudo da cinética de secagem em camada fina foi feito com temperaturas de 40, 55 e 70 ºC, velocidade do ar de secagem de 0,2, 0,5 e 0,8 m/s. Foi ajustado o modelo de Page aos dados experimentais para obter a curva de secagem. Para realizar a parte experimental da secagem foi projetado e construído um secador em escala laboratorial para secagem em camada espessa e em camada fina, simultaneamente, com capacidade para secar oito quilos de grão em camada espessa e um quilo em camada fina. A secagem em camada espessa do produto foi feita a temperaturas de 50, 60 e 70 ºC, em camada com espessura de 60 cm e vazão do ar de secagem de 0,59 m3/min. Utilizou-se o modelo proposto por BAKKER-ARKEMA et al. (1974) - Modelo da Universidade Estadual de Michigan (M.S.U.) – e o modelo de Thompson para simular o processo de secagem. A discretização das equações diferenciais foi feita pelo método dos volumes finitos, utilizando-se uma formulação explícita e a função de interpolação espacial “upwind”. / The behavior of cowpea been’s physical properties was studied (Vigna unguiculata (l.) Walpers) - porosity, surface area, specific area, specific heat, bulk density and the relative equilibrium humidity, - with initial moisture content range 20, 40 and 65 %, wet basis, the initial moisture effects content the product, the temperature and the air drying speed , on kinetic of product drying. The relative equilibrium humidity of cowpea been with initial moisture content range 65 %, wet basis, had been determined by the static method, for temperatures of 20, 30, 40 and 50 ºC, with relative humidity varying between 0,10 and 0,85, decimal. For experimental data’s analysis, five mathematical models had been used: Henderson-Thompson’s; Henderson- Thompson’s model modified by Cavalcanti Mata; Chung-Pfost’s model; Oswin’s modified model; Halsey’s modified model. The study of the drying kinetic in thin-layer was made with temperatures of 40, 55 and 70 ºC, air drying speed of 0,2, 0,5 and 0,8 m/s. The Page’s model was adjusted to the experimental data to get the drying curve. To carry through the drying experimental part was projected and buidet a drier in laboratorial scale for fixed-bed drying and thin-layer , simultaneously, with capacity to dry eight kilos of grain in thick layer and one kilo in fine layer. The fixed-bed drying of the product was made with temperatures of 50, 60 and 70 ºC, in layer with thickness of 60 cm and air outflow of 0,59 drying of m3/min. The considered BAKKERARKEMA’s et al (1974) model was used. - Model of the Michigan State University (M.S.U.) - and Thompson’s model to simulate the drying process. Discretization of the differential equations was made by the finite volumes method, using an explicit formularization and the function of upwind space interpolation.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-20T14:53:19Z No. of bitstreams: 1 RAFAEL FELICIANO DE MACEDO - DISSERTAÇÃO (PPGEM) 2016.pdf: 2450378 bytes, checksum: 8713991eb748af68688b453a22a55116 (MD5) / Made available in DSpace on 2018-08-20T14:53:19Z (GMT). No. of bitstreams: 1 RAFAEL FELICIANO DE MACEDO - DISSERTAÇÃO (PPGEM) 2016.pdf: 2450378 bytes, checksum: 8713991eb748af68688b453a22a55116 (MD5) Previous issue date: 2016-12-19 / Capes / O presente trabalho trata do estudo teórico e experimental do processo de secagem de argila bentonita em secador rotativo contínuo industrial. Foram realizados testes experimentais em campo, onde foi possível coletar e medir parâmetros geométricos do secador, fluxo mássico, temperatura do ar e do material. Foi estabelecido um modelo matemático a ser utilizado para a análise da eficiência global teórica idealizada e real do secador rotativo. Resultados teóricos do teor de umidade, temperatura do ar e do material na saída do secador, além da eficiência global do equipamento em várias condições de secagem foram apresentados e analisados. Verificou-se que o modelo real da simulação mostrou que o secador rotativo quando operado em certas condições ambientes na planta de instalação possui eficiência e desempenho adequado conforme sugere a literatura. Parâmetros como tempo de residência, velocidade rotacional e velocidade do ar quando manipulados corretamente pode-se obter melhores resultados na secagem do produto de argila bentonita visando a redução do consumo de combustível. Além dos testes dos parâmetros, sugestões para futuros estudos como, a determinação da cinética de secagem e curvas de sorção da argila são de essencial importância para garantir a especificação do teor de umidade final do produto. / The present work deals with the theoretical and experimental study of the drying process of bentonita clay in an industrial continuous rotary dryer. Experimental tests were performed in the field, where it was possible to collect and measure geometric parameters of the dryer, mass flow, air and material temperature. It was proposed a mathematical model to be used for the analysis of the idealized and real theoretical global efficiency of the rotary dryer. Theoretical results of moisture content, air temperature and material at the dryer outlet, besides the overall equipment efficiency under various drying conditions were presented and analyzed. It was verified that the real simulation model showed that the rotary dryer when operated in certain ambient conditions in the installation plant has efficiency and adequate performance as suggested by the literature. Parameters such as residence time, speed of rotation and air velocity when handled properly, better results can be obtained in the drying of the bentonita clay product in order to reduce fuel consumption. In addition to the parameter tests, as future studies, the determination of drying kinetics and sorption curves of the clay are of essential importance to ensure the specification of the final moisture content of the product.

Nous nous sommes intéressés à la problématique d’organisation des tournées de soins à domicile dans le cadre de structures de maintien à domicile comme par exemple les service d’Hospitalisation À Domicile ou les Services de Soins Infirmiers À Domicile. Les soins sont prodigués au domicile des patients par un ou deux soignants d’un type défini, comme médecin ou infirmier par exemple pendant une période de disponibilité du patient. Le patient est caractérisé par un niveau de dépendance et peut exprimer une préférence pour être soigné par un soignant plutôt qu’un autre. L’objectif est de construire les tournées des soignants en rendant visite à tous les patients tout en minimisant la longueur (ou durée) des tournées, en équilibrant les tournées suivant le niveau de dépendance des patients et en favorisant la préférence des patients. Après avoir réalisé un état de l’art des problèmes d’organisation de tournées de soins à domicile, nous proposons deux modélisations mathématiques de notre problème sous la forme d’un multiple Traveling Salesman Problem avec fenêtres de temps (m-TSPTW) auquel s’ajoute des contraintes spécifiques comme la synchronisation d’activités ou la prise en compte de types de ressource et des critères de performance propres au problème (équilibrage et préférence). Nous avons ensuite proposé des méthodes approchées basées sur des couplages métaheuristique - modèle de simulation testées sur des instances de la littérature d’un problème proche du nôtre et des instances adaptées à notre problème. Pour terminer, nous abordons trois perspectives de recherche :- la réorganisation des tournées suite à l’absence d’un soignant,- la prise en compte de temps de transport stochastique,- la localisation de structures de maintien à domicile et l’impact sur la construction des tournées. / We are interested in a routing problem within the context of home health care. The cares are provided by one or two caregivers with the required type at the patient’s home during the patients’ availability. A type is doctor or nurse for instance. Each patient is characterized by a dependency level and may give a preference for a caregiver. The goal is to construct the tour for each caregiver visiting all patients, minimizing the length of the tours, balancing the workload of the caregivers and maximizing the satisfaction of the patients. We present a state of the art of the home health care problem. Then we propose two mathematical models of our problem based on the multiple Traveling Salesman Problem with Time Windows (m-TSPTW) with specific constraints like the activities’s synchronization or ressources’ type. The performance criteria are specific of our problem : workload balancing and patients’ satisfaction. We then propose approached methods based on combination between Metaheuristics and simulation model. This méthods have been tested on dataset from the literature and dataset adapted to our problem. We conclude with three research perspectives :- the reorganization of the tours when a caregiver is not available,- the integration of stochastic transport time,- the location of home support structure and its impact on the routes’ construction.