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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

The reinforcement learning method : A feasible and sustainable control strategy for efficient occupant-centred building operation in smart cities

May, Ross January 2019 (has links)
Over half of the world’s population lives in urban areas, a trend which is expected to only grow as we move further into the future. With this increasing trend in urbanisation, challenges are presented in the form of the management of urban infrastructure systems. As an essential infrastructure of any city, the energy system presents itself as one of the biggest challenges. As cities expand in population and economically, global energy consumption increases and as a result so do greenhouse gas (GHG) emissions. To achieve the 2030 Agenda’s sustainable development goal on energy (SDG 7), renewable energy and energy efficiency have been shown as key strategies for attaining SDG 7. As the largest contributor to climate change, the building sector is responsible for more than half of the global final energy consumption and GHG emissions. As people spend most of their time indoors, the demand for energy is made worse as a result of maintaining the comfort level of the indoor environment. However, the emergence of the smart city and the internet of things (IoT) offers the opportunity for the smart management of buildings. Focusing on the latter strategy towards attaining SDG 7, intelligent building control offers significant potential for saving energy while respecting occupant comfort (OC). Most intelligent control strategies, however, rely on complex mathematical models which require a great deal of expertise to construct thereby costing in time and money. Furthermore, if these are inaccurate then energy is wasted and the comfort of occupants is decreased. Moreover, any change in the physical environment such as retrofits result in obsolete models which must be re-identified to match the new state of the environment. This model-based approach seems unsustainable and so a new model-free alternative is proposed. One such alternative is the reinforcement learning (RL) method. This method provides a beautiful solution to accomplishing the tradeoff between energy efficiency and OC within the smart city and more importantly to achieving SDG 7. To address the feasibility of RL as a sustainable control strategy for efficient occupant-centred building operation, a comprehensive review of RL for controlling OC in buildings as well as a case study implementing RL for improving OC via a window system are presented. The outcomes of each seem to suggest RL as a feasible solution, however, more work is required in the form of addressing current open issues such as cooperative multi-agent RL (MARL) needed for multi-occupant/multi-zonal buildings.
52

Occupant Response Metrics and Their Applicability to a Roll Simulator

Yoder, Steven J. 19 December 2011 (has links)
No description available.
53

Human-Building Symbiotic Communication with Voice-based Proactive Smart Home Assistants

He, Tianzhi 29 January 2021 (has links)
The IoT-embedded smart homes have a high level of home automation and could change many aspects of the residents' daily lives, such as control, convenience, comfort, and energy-saving. The rise of voice-based virtual assistants like Amazon's Alexa, Google assistants in the past five years has brought new potentials to provide occupants with a convenient and intuitive interface to interact with smart homes through conversations. However, the one-way communications in the form of user commands to control building systems does not result in the optimal course of actions. As such, in this thesis, we proposed the concept of proactive smart home assistants and explored the occupants' perception towards smart home assistants proactively providing suggestions to adapt them into energy-saving behaviors. We also investigated the impact of occupants' personal features on their intention in taking energy-saving behaviors. A comprehensive data collection was conducted through online surveys, in which 307 valid responses with participant's personal profile information, their perceptions of smart home assistants, and their feedback to our designed messages were collected. The first manuscript compared participants' responses to traditional plain-text energy-saving suggestions and suggestions provided by smart home assistants. The nudging effect of smart home assistants was justified to be significant in affecting occupant's energy-saving behaviors. Occupant's thermal comfort range, smart home device previous experience, values and beliefs were then proved to have significant impact on their intention in taking the smart home assistant's suggestions. The second manuscript fitted 21 personal characteristics features in machine learning models (SVM, Random Forest, Logistic Regression) to predict occupant's intention and attitude towards energy-saving suggestions. The results indicated that occupant's beliefs about interests in taking actions and beliefs about energy expenses, occupant's education level, residence occupancy type, thermal comfort ranges, and smart home device experiences are important features in occupants' energy-saving behavior intention prediction. This research demonstrates the effect of proactive smart home assistants in human-building interaction as well as the impact of personal characteristic features on occupant's energy-saving behaviors, paving a path to the future development of bi-directional human-building communication. / Master of Science / With the technology development in the fields of the Internet of Things (IoT), smart homes have made it possible to help occupants conserve energy in an efficient way without sacrificing the occupants' comfort. The rise of voice-based virtual assistants like Amazon's Alexa, Google assistants accompany the proliferation of smart speaker products in the past five years has brought new potentials to provide occupants with a convenient and intuitive interface to interact with smart homes through conversations. Based on IoT, the virtual assistants are able to control a broad range of Wi-Fi connected home devices like thermostats, lighting systems, and security systems. As such, through the simple wake words (e.g., "Alexa", "Hey, Google"), occupants can easily control the home environment with their voice commands. Despite the potentials brought by these voice-based virtual assistants, it has been shown that users might not know about all the supported features and limit their interaction with smart home assistants to simple daily tasks. The one-way communications in the form of user commands to control building systems do not result in the optimal course of actions. Therefore, in this study, we have envisioned that these virtual assistants, coupled with their corresponding smart home ecosystems could act proactively as a bridge to facilitate human-building interaction and achieve goals like nudging occupants to adopt sustainable and healthy behaviors. A comprehensive data collection was conducted through online surveys, in which 307 valid responses with participant's personal profile information, their perceptions of smart home assistants, and their feedback to our designed messages were collected. The first manuscript compared participants' responses to traditional plain-text energy-saving suggestions and suggestions provided by smart home assistants. The nudging effect of smart home assistants was justified to be significant in affecting occupant's energy-saving behaviors. Occupant's thermal comfort range, smart home device previous experience, values and beliefs were then proved to have significant impact on their intention in taking the smart home assistant's suggestions. The second manuscript fitted 21 personal characteristics features in machine learning models (SVM, Random Forest, Logistic Regression) to predict occupant's intention and attitude towards energy-saving suggestions. The results indicated that occupant's beliefs about interests in taking actions and beliefs about energy expenses, occupant's education level, residence occupancy type, thermal comfort ranges, and smart home device experiences are important features in occupants' energy-saving behavior intention prediction. This research demonstrates the effect of proactive smart home assistants in human-building interaction as well as the impact of personal characteristic features on occupant's energy-saving behaviors, paving a path to the future development of bi-directional human-building communication.
54

Programspråk specificerade av nyttjare : en pilotstudie om tidsåtgång vid uppmärkning av dokument

Bragner, Johan, Wasing, Malin January 2016 (has links)
IT-projekt misslyckas ofta för att de blir sena och dyrare än planerat, och i många fall är det tidsfaktorn som är begränsande för projekten. Det existerar många olika programspråk och behov att dela konstruktioner mellan dessa. Idag använder applikationer inom samma system ofta olika terminologi och behovet av konverteringar uppkommer. Det existerar standardiserade språk som till exempel märkspråket XML men då organisationer väljer att skapa sin egen syntax för att formatera publiceringar kan ett motstånd urskiljas. Uppsatsen kan användas som underlag för vidare forskning inom programspråk. Denna studie fokuserar på att jämföra om val av syntax har någon betydelse för tidsåtgången vid uppmärkning av dokument. Den valda forskningsstrategin är experiment. En pilotstudie utfördes och med resultatet från studien gjordes en hypotesprövning i form av ett t-test. Analysen av resultatet antydde att användandet av valfri syntax implicerade en mindre tidsåtgång vid uppmärkning av dokument än vid användandet av XML. Från analysen konstateras det att ämnet bör undersökas vidare och att studien bör genomföras i större omfattning. / IT projects often fail because they are late and more expensive than planned, and in many cases it is the time factor that is limiting for projects. There exist many different programming languages and the need to share structures between them. Applications within the same system often uses different terminology and the need for conversions occurs. Standardized languages such as XML exist but when organizations choose to create their own syntax for formatting publications instead a resistance can be distinguished. The paper can be used as basis for further research in the area of programming languages. This research focuses on comparing if the choice of syntax affects expenditure of time when marking document. The selected research strategy is experiment. A pilot study has been done and based on the results of the study a hypothesis testing (t-test) was made. The analysis of the results indicated that the use of optional syntax implied that less time was spent at marking document than the use of XML. The conclusion from this was that this area should be further explored and that the study should be done on a larger scale.
55

Estudo do desempenho de reforços poliméricos em estruturas veiculares submetidas a impacto. / Study of polimeric reinforcements in vehicular structures subjected to impacts.

Matsumoto, André Takashi 25 March 2010 (has links)
O objetivo deste trabalho é mostrar a aplicação de reforços estruturais pré-moldados utilizando o material polimérico PA66 através de simulações em elementos finitos na área de segurança veicular. Os reforços estruturais pré-moldados têm mostrado bom desempenho em testes de impacto, onde a grande vantagem está em seu reduzido peso. Estes reforços são projetados com o intuito de aumentar a rigidez das regiões que estão sujeitas a grandes deformações, estabilizando as seções do veículo que trabalham como caminho de carga durante o impacto. Inicialmente, foram executados testes estáticos e dinâmicos para caracterizar o material PA66, que foi utilizado nas simulações. Os casos de impacto estudados foram aqueles que serão adotados pelo CONTRAN em 2012 e já são adotados por outras normas de grande importância para a segurança do ocupante, como a ECE-R94, ECE-R12, ECE-R95, ECE-R32/34 e a FMVSS216. As simulações executadas no software LS-Dyna ® e MADYMO ® com a aplicação do reforço mostraram, no caso do impacto frontal na configuração ODB a 57km/h, uma redução de 70% na deformação da coluna A, bem como uma redução de 65% na deformação da coluna de direção e uma redução de, aproximadamente, 59% na região das pernas e pés do ocupante. O nível de lesões do ocupante pôde ser avaliado através do software MADYMO ® , e foi possível verificar uma redução de 23,5% na compressão do peito, 80% de compressão na tíbia, o que levaria o ocupante do veículo com este tipo de reforços sair ileso de uma colisão nas condições da norma. A aplicação dos reforços no impacto lateral possibilitou uma redução de 13,8m/s para 10,6m/s na velocidade de deformação da coluna B na região das costelas do dummy e houve um ganho de 140mm de espaço residual. Os reforços adotados para o impacto frontal e lateral proporcionaram um aumento de 47,5% de força de colapso da estrutura superior, segundo a norma FMVSS216. / The objective of this work is to show the application of structural reinforcements using the polymeric material PA66 through finite element simulations in the field of vehicle safety. The preformed structural reinforcements have shown good performance in crash tests, where the great advantage is their reduced weight. These reinforcements are designed with the aim of increasing the rigidity of regions which are prone to large deformations, stabilizing sections of the vehicle that works as load path during the impact. Initially, static and dynamic tests were performed to characterize the material PA66, which was used in the simulations. The impact cases studied were those which will be adopted by CONTRAN in 2012 and already adopted by other standards of great importance for the occupant safety, such as ECE-R94, ECE-R12, ECE-R95, ECE-R32/34 and FMVSS216. The simulations performed in the software LS-Dyna ® and MADYMO ® considering the application of reinforcements in the case of frontal impact regarding ODB at 57km/h configuration, resulted in 70% reduction in the A pillar deformation and 65% in the deformation of the steering column and a reduction of approximately 59% in the occupant\'s legs and feet region. The occupant\'s injury level were assessed by MADYMO ® software, and a reduction of 23.5% in the chest compression and 80% in the tibia compression were verified. Such conditions lead the safety of an occupant of the vehicle with reinforcements in a collision event according to the standard. The application of reinforcements on side impact load case contributed to reduce the B pillar velocity at the dummy\'s ribs region from 13.8 m/s to 10.6 m/s and there was a gain of 140mm of B pillar residual space. Reinforcements adopted for the front and side impact load cases provided an increase of 47.5% in the upper structure crush force, according to FMVSS216 standard.
56

The behaviour of rollover protective structures subjected to static and dynamic loading conditions

Clark, Brian January 2005 (has links)
The Rollover of heavy vehicles operating in the construction, mining and agricultural sectors is a common occurrence that may result in death or severe injury for the vehicle occupants. Safety frames called ROPS (Rollover Protective Structures) that enclose the vehicle cabin, have been used by heavy vehicle manufacturers to provide protection to vehicle occupants during rollover accidents. The design of a ROPS requires that a dual criteria be fulfilled that ensures that the ROPS has sufficient stiffness to offer protection, whilst possessing an appropriate level of flexibility to absorb some or most of the impact energy during a roll. Over the last four decades significant research has been performed on these types of safety devices which has resulted in the generation of performance standards that may be used to assess the adequacy of a ROPS design for a particular vehicle type. At present these performance standards require that destructive full scale testing methods be used to assess the adequacy of a ROPS. This method of ROPS certification can be extremely expensive given the size and weight of many vehicles that operate in these sectors. The use of analytical methods to assess the performance of a ROPS is currently prohibited by these standards. Reasons for this are attributed to a lack of available fundamental research information on the nonlinear inelastic response of safety frame structures such as this. The main aim of this project was to therefore generate fundamental research information on the nonlinear response behaviour of ROPS subjected to both static and dynamic loading conditions that could be used to contribute towards the development of an efficient analytical design procedure that may lessen the need for destructive full scale testing. In addition to this, the project also aspired to develop methods for promoting increased levels of operator safety during vehicle rollover through enhancing the level of energy absorbed by the ROPS. The methods used to fulfil these aims involved the implementation of an extensive analytical modelling program using Finite Element Analysis (FEA) in association with a detailed experimental testing program. From these studies comprehensive research information was developed on both the dynamic impact response and energy absorption capabilities of these types of structures. The established finite element models were then used to extend the investigation further and to carry out parametric studies. Important parameters such as ROPS post stiffness, rollslope inclination and impact duration were identified and their effects quantified. The final stage of the project examined the enhancement of the energy absorption capabilities of a ROPS through the incorporation of a supplementary energy absorbing device within the frame work of the ROPS. The device that was chosen for numerical evaluation was a thin walled tapered tube known as frusta that was designed to crush under a sidewards rollover and hence lessen the energy absorption demand placed upon the ROPS. The inclusion of this device was found to be beneficial in absorbing energy and enhancing the level of safety afforded to the vehicle occupants.
57

Prédiction des performances énergétiques des bâtiments avec prise en compte du comportement des usagers / Buildings energy performance prediction including occupants' behaviours

Darakdjian, Quentin 05 July 2017 (has links)
L’amélioration continue de la performance énergétique des bâtiments a été accompagnée par un développement d’outils numériques de plus en plus performants et précis. Alors que la prise en compte des phénomènes liés aux bâtiments, aux systèmes et à la météorologie est bien maîtrisée, le comportement des occupants est modélisé de manière très simplifiée par des scénarii répétitifs et des lois déterministes. L’impact des occupants sur les consommations énergétiques dans les bâtiments performants est pourtant majeur, comme en témoigne les écarts récurrents entre les résultats prédits et mesurés. Le travail de thèse propose, par l’intermédiaire d’une plateforme multi-agents et de modèles stochastiques, une mise à jour de la prise en compte de la présence des occupants et de leurs comportements sur la gestion des ouvrants, des dispositifs d’occultation, de l’éclairage et de la température de consigne de chauffage. Le champ d’application de la plateforme concerne les bâtiments de bureaux et de logements, pour des opérations neuves et de rénovation. Les modèles de comportement des occupants sont idéalement issus de campagnes de mesures in situ, d’études de laboratoire ou d’enquêtes sociologiques. La plateforme proposée est alors co-simulée avec le logiciel EnergyPlus, afin d’étudier l’influence des modèles sur les performances énergétiques. Dans la perspective de garantie de performance énergétique, ce travail contribue à la mise à jour et à la fiabilisation des outils de prédiction. / Continuous improvement of the building energy performance is associated with the development of increasingly efficient and accurate numerical tools. While the consideration of phenomena related to buildings, systems and weather is well mastered, occupants’ behaviours are modelled in a very simplified way by repetitive scenarios and deterministic laws. The impact of occupants on energy consumption in high-performance buildings is dominant, as evidenced by the recurring gaps between predicted and measured results. The thesis demonstrates, via a multi-agent platform and stochastic models, an update on the ability to model occupants’ presence, their behaviours on windows, occultation devices, artificial lighting and heating setpoint temperatures. The application of the platform applies to office and residential buildings, for new builds and refurbishments. Occupants’ behaviour models are ideally obtained from in situ surveys, laboratory studies or sociological works. The suggested platform is then co-simulated with the EnergyPlus software, to study the influence of the models on a buildings energy performance. In the perspective of energy performance guarantees, this work contributes to the updating and reliability of prediction tools.
58

Estudo do desempenho de reforços poliméricos em estruturas veiculares submetidas a impacto. / Study of polimeric reinforcements in vehicular structures subjected to impacts.

André Takashi Matsumoto 25 March 2010 (has links)
O objetivo deste trabalho é mostrar a aplicação de reforços estruturais pré-moldados utilizando o material polimérico PA66 através de simulações em elementos finitos na área de segurança veicular. Os reforços estruturais pré-moldados têm mostrado bom desempenho em testes de impacto, onde a grande vantagem está em seu reduzido peso. Estes reforços são projetados com o intuito de aumentar a rigidez das regiões que estão sujeitas a grandes deformações, estabilizando as seções do veículo que trabalham como caminho de carga durante o impacto. Inicialmente, foram executados testes estáticos e dinâmicos para caracterizar o material PA66, que foi utilizado nas simulações. Os casos de impacto estudados foram aqueles que serão adotados pelo CONTRAN em 2012 e já são adotados por outras normas de grande importância para a segurança do ocupante, como a ECE-R94, ECE-R12, ECE-R95, ECE-R32/34 e a FMVSS216. As simulações executadas no software LS-Dyna ® e MADYMO ® com a aplicação do reforço mostraram, no caso do impacto frontal na configuração ODB a 57km/h, uma redução de 70% na deformação da coluna A, bem como uma redução de 65% na deformação da coluna de direção e uma redução de, aproximadamente, 59% na região das pernas e pés do ocupante. O nível de lesões do ocupante pôde ser avaliado através do software MADYMO ® , e foi possível verificar uma redução de 23,5% na compressão do peito, 80% de compressão na tíbia, o que levaria o ocupante do veículo com este tipo de reforços sair ileso de uma colisão nas condições da norma. A aplicação dos reforços no impacto lateral possibilitou uma redução de 13,8m/s para 10,6m/s na velocidade de deformação da coluna B na região das costelas do dummy e houve um ganho de 140mm de espaço residual. Os reforços adotados para o impacto frontal e lateral proporcionaram um aumento de 47,5% de força de colapso da estrutura superior, segundo a norma FMVSS216. / The objective of this work is to show the application of structural reinforcements using the polymeric material PA66 through finite element simulations in the field of vehicle safety. The preformed structural reinforcements have shown good performance in crash tests, where the great advantage is their reduced weight. These reinforcements are designed with the aim of increasing the rigidity of regions which are prone to large deformations, stabilizing sections of the vehicle that works as load path during the impact. Initially, static and dynamic tests were performed to characterize the material PA66, which was used in the simulations. The impact cases studied were those which will be adopted by CONTRAN in 2012 and already adopted by other standards of great importance for the occupant safety, such as ECE-R94, ECE-R12, ECE-R95, ECE-R32/34 and FMVSS216. The simulations performed in the software LS-Dyna ® and MADYMO ® considering the application of reinforcements in the case of frontal impact regarding ODB at 57km/h configuration, resulted in 70% reduction in the A pillar deformation and 65% in the deformation of the steering column and a reduction of approximately 59% in the occupant\'s legs and feet region. The occupant\'s injury level were assessed by MADYMO ® software, and a reduction of 23.5% in the chest compression and 80% in the tibia compression were verified. Such conditions lead the safety of an occupant of the vehicle with reinforcements in a collision event according to the standard. The application of reinforcements on side impact load case contributed to reduce the B pillar velocity at the dummy\'s ribs region from 13.8 m/s to 10.6 m/s and there was a gain of 140mm of B pillar residual space. Reinforcements adopted for the front and side impact load cases provided an increase of 47.5% in the upper structure crush force, according to FMVSS216 standard.
59

Développement d'une démarche d’aide à la connaissance pour la conception de bâtis performants / Development of a knowledge-aid approach for designing high-performance buildings

Talbourdet, Fabien 25 September 2014 (has links)
Les demandes des usagers conjuguées à la réglementation nécessitent de concevoir des bâtiments de plus en plus confortables et économes en énergie. En parallèle de ces exigences, les réglementations concernant les bâtiments sont renforcées dans différents domaines (acoustique, sécurité incendie, risque sismique,…) afin d’obtenir des bâtiments plus sûrs et correspondant aux demandes des usagers. Les impacts conjugués de ces deux facteurs engendrent une complexification de la conception des bâtiments.Cette thèse présente une démarche d’aide à la connaissance pour la conception de bâtis performants se basant sur une méthode d’optimisation. Cette démarche vise à ce que les architectes et les bureaux d’études aient une connaissance claire du potentiel de leur projet (exploration de solutions) en phase amont de conception, pour concevoir des bâtiments les plus performants possibles. Ce potentiel est évalué via des paramètres de la géométrie extérieure et intérieure ainsi que des caractéristiques énergétiques du bâti. La démarche leur permet également d’évaluer les avantages et inconvénients de différentes géométries et solutions de conception qu’ils envisagent pour répondre à leurs projets. Cette démarche est appliquée à un immeuble de bureaux à Lyon.Pour le cas testé, la démarche permet d’obtenir rapidement des solutions performantes et de définir pour certains des paramètres étudiés, des valeurs conduisant aux solutions performantes dans une partie de l’espace des solutions ou dans l’ensemble de cet espace.Cette application de la démarche montre également qu’il peut exister des solutions ayant des besoins énergétiques et des coûts de construction proches mais étant très différentes en termes de paramètres de conception. Bien que remettant en cause l'applicabilité directe de la démarche, ce résultat met en exergue un problème nouveau. Cette thèse pose alors les bases pour une nouvelle étude. / Both aspirations of users and improvements in the thermal regulation require that the comfort and the energy efficiency of new buildings improve. In addition to these requirements, regulations are strengthening in many fields such as acoustics, fire safety and mechanical performance. The combined effects of these factors are making it increasingly hard to design buildings. This thesis presents a knowledge-aid approach for designing high-performance buildings based on an optimization method. This approach aims to provide clear knowledge of the potential of projects (exploration of various options) for architects and design offices at the beginning of the design that will allow them to design the best possible high-performance buildings. This potential is evaluated using external and internal geometric parameters as well as the energy characteristics of buildings. This approach also allows them to assess geometries and design solutions which are intended to be used for their projects.This approach will be applied to an office building in Lyon, France. For the tested case, the approach obtains quickly efficient solutions and also finds, for some parameters, values to design efficient solutions on part of the Paretofront or in this entire front. This application of the approach also shows that there may be solutions which are close in terms of energy needs and cost but could be very different on design parameters. This problem could influence robustness of the approach but highlights a new problem. This thesis then lays the foundation of a new study on this topic.
60

Urban Water Demand Simulation in Residential and Non-Residential Buildings Based on a CityGML Data Model

Bao, Keyu, Padsala, Rushikesh, Thrän, Daniela, Schröter, Bastian 13 April 2023 (has links)
Humans’ activities in urban areas put a strain on local water resources. This paper introduces a method to accurately simulate the stress urban water demand in Germany puts on local resources on a single-building level, and scalable to regional levels without loss of detail. The method integrates building geometry, building physics, census, socio-economy and meteorological information to provide a general approach to assessing water demands that also overcome obstacles on data aggregation and processing imposed by data privacy guidelines. Three German counties were used as validation cases to prove the feasibility of the presented approach: on average, per capita water demand and aggregated water demand deviates by less than 7% from real demand data. Scenarios applied to a case region Ludwigsburg in Germany, which takes the increment of water price, aging of the population and the climate change into account, show that the residential water demand has the change of −2%, +7% and −0.4% respectively. The industrial water demand increases by 46% due to the development of economy indicated by GDP per capita. The rise of precipitation and temperature raise the water demand in non-residential buildings (excluding industry) of 1%.

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