Browsing Faculty of Engineering & IT (Theses and Dissertations) by Issue Date
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ItemSpeech-to-speech example based translation: English to Arabic(The British Univesity in Dubai (BUiD), 2006-10) Mirza, Ali Arshad ItemThe Role of Shading as a Passive Strategy in Traditional Built Environment in Hot Climate(The British University in Dubai (BUiD), 2007-11) Tehrani, AmirHassan MajidiSome Middle Eastern countries are located in the hot climate zone and are rich in natural resources particularly oil and gas. In recent years, due to the high income from oil, they have started to develop the urban fabric rapidly and in an unsustainable way and as a result a large amount of natural resources have been consumed. Sustainability can restore the balance in using energy and resources and in providing sustainable urban development. Passive cooling strategies are the first approach towards establishing a sustainable built environment in the Middle East. There are several passive solutions in this region which were introduced hundreds of years ago such as the Badgir (wind tower) and a number of studies have been conducted in order to investigate the performance and possibilities of using these solutions in the current built environment. The aim of this research is to investigate the impact of shading as a selected passive solution as the first phase of sustainable design. The cities of Yazd (Iran) and Bastakya (Dubai-UAE) are introduced as case studies in order to assess the impacts of shading from thermal, visual and psychological aspects on human comfort in the local traditional built environment. The methodology combines simulation, site visits, field measurements and relevant research to analyze thoroughly the effects of shading on the urban fabric and individual building. The results reveal the advantages of the compact urban fabric and courtyard housing in providing shading to improve human comfort in the traditional built environments in Yazd and Bastakya. The shading disadvantages are also discussed. The conclusion provides a summary of the findings and the outlook presents the results in order to integrate shading as the primary passive solution in future development in both locations or anywhere with similar climatic and cultural patterns. ItemDistributed and Flexible workflow coordination using defeasible logic programming(The British University in Dubai (BUiD), 2007-12) PV, SakeerThis is an exploration to foretell a future in which traditional approaches for developing workflow management systems can be supplanted by new techniques and emerging technologies. This thesis recommends sets of methodologies for performing multiagent-based distributed and flexible workflow systems. Its objective is to deal with some of the present issues in the traditional workflow system from the business point of view. This thesis proposes that the traditional design of workflow management systems (clientserver) could be replaced by a defeasible logic programming (DeLP) engine-based multiagent platform that is more flexible and can better replicate workflow’s distributed characteristics in the open environment. This thesis presents sets of technologies for enacting multiagent-based distributed and flexible workflow systems. Its purpose is to tackle some of the existing problems in the traditional workflow system from the business point of view. This thesis proposes that the conventional system architecture of workflow management systems (client-erver) could be replaced by a defeasible logic programming (DeLP) engine–based multiagent platform that is more open and collaborative, and can better reflect workflow’s distributed features in the open environment. This system also eliminates the requirement for centralized workflow coordination and proposes to build a flexible and distributed workflow management system using a multiagent system on a java agent development (JADE) framework, where the workflow semantics and business logic are built using DeLP. The main outcome of this research is to provide approaches for utilizing defeasible logic programming methodologies in application development, especially in business applications, where DeLP can contribute much for the automation of business logic. Moreover, a multiagent system on a JADE framework helps to maximize the use of existing process models and tools for automation of business processes. The model implemented as part of this thesis confirms that a workflow framework using DeLP improves the adaptability and decentralization of workflow management. ItemDecreasing the CO2 emissions and the embodied nergy in the UAE through the selection of sustainable building materials in the construction phase(The British University in Dubai (BUiD), 2008-01) Saadah, Yasmeen SamiA great quantity of CO2 is emitted to the atmosphere through the different phases of a building life cycle: in the production of materials and products, in the construction of the building itself, in the setting of the site, in the exploitation, the renovations, the later rehabilitations, up to the final demolition. The purpose of this study is to quantify the total amount of CO2 emissions and embodied energy that can be saved by the method presented in the particular phase of the material selection within the life cycle of a building. This material selection, as well as the bioclimatic characteristics, must be defined from the early design project phase. As a result, the research shows the possibility of reducing the embodied energy in building materials up to 53% and the CO2 emissions produced up to 59% in the construction phase, through a careful selection of building materials with sustainable features. ItemInfrastructure for Mass Argumentation Support on the Semantic Web(The British University in Dubai (BUiD), 2008-03) Banihashemi, BitaIn this thesis,I present an OWL ontology for describing arguments and argument schemes. Following the same key principles of the World Wide Argument Web (WWAW) for building a large-scale Web of structured and inter-connected arguments, this ontology provides an infrastructure for mass argumentation support on the Web.First, I describe the OWL ontology which is based on a new reification of the Argument Interchange Format (AIF) and structures arguments according to Walton’s theory of argumentation schemes. Then, I demonstrate how this ontology enables the use of automated Description Logic reasoning over argument structures. In particular, OWL reasoning enables significantly enhanced querying of arguments through automatic scheme classifications, instance classification, inference of indirect support in chained argument structures and inference of critical questions. Finally, I present the implementation of a Web-based system for authoring and querying argument structures in RDF which utilizes the proposed OWL ontology. ItemIncreasing the air flow between buildings in high density urban areas in Ras Al-Khaimah, UAE(The British University in Dubai (BUiD), 2008-03) Al-Badi, Abdulwahed Hasan Saeed HasanThis research is a study of how to increase the flow of natural ventilation in a high density urban area. It was carried out in Ras Al Khaimah (RAK) city in the United Arab Emirates (UAE). Distance between the buildings is an important variable in promoting ventilation in urban design. High density zones in RAK cause poor ventilation and the small distance between buildings prevent deeper penetration by the wind. Thus, the scope of the study is to raise the amount of natural ventilation in high density urban areas in RAK. A review of literature on the research topic is provided in this study while both quantitative and qualitative data were collected through numerical simulation, experimental approach and case study in order to maintain both reliability and validity. The results of this research revealed that there is a considerable improvement in the airflow movements around the buildings after the urban parameters of the study area have been modified. ItemHuman Computation for Ontology Refinement(The British University in Dubai (BUiD), 2008-06) Bussanad Alshamsi, Suaad SalemOntology plays an important role in enabling the Semantic Web. Ontologies are used to represent a shared and common understanding of a domain of interest. The main bottleneck is knowledge acquisition in a dynamic environment like the Web. There are several projects that attempts to collect commonsense knowledge, but none of them has explored how to present and use this knowledge in real life. This project explores the possibility of using human computation concepts to devise an online game that enables people to contribute to the process of generating Semantic Web ontologies.The project presents the Ontology Re nement System which generates ontologies from the knowledge acquired by the online game. The system is divided into three main components. The rst component is the Online Game which is used as a tool to collect commonsense knowledge from a large community of people. The second component is the Ontology Builder which represents an algorithm used to illustrate how to process and transfer the knowledge collected into a set of statements. This component is the prime contribution of the project. The third component in the system is the Ontology Representation Generator which takes the set of statements produced by the second component and generates OWL ontology les using Jena API. An experiment has been conducted to evaluate the e ciency of the Ontology Re nement System. Three different ontologies were produced by the system from the knowledge collected during the experiment. A survey about the ontologies produced by the experiment has been sent randomly to Internet users to measure the accuracy of these ontologies. The survey results in a good agreement from the Internet users on the ontologies produced. The ontologies that are produced by the Ontology Re nement System are particularly rel- evant to domains in which ontologies change over time such as electronic commerce. Ontologies can be used to maintain a constantly evolving and improving product catalogue. A good product catalogue can make it easier for people to navigate the available products to find information. ItemAn Online Cognitive, Adaptive, Practice based Approach for ITS: An Approach to IT professional certifications(The British University in Dubai (BUiD), 2008-10) Duweik, Hikmat JadallaWith the development of WWW technology, web-based Intelligent Tutoring Systems (ITSs) are becoming an important area of research and development. The key benefit of web-based ITS is that it can be accessed by thousands of learners all over the world. Even though many web-based educational systems have been developed recently, most of them are restricted in functionality, do not provide direction and guidance for individualized learning, and thus fail to take advantage of the distributed nature of the Internet.In this thesis, we present an approach to a practice-based adaptable web-based cognitive intelligent tutoring system that has been applied to build a system that prepares learners for the exam of the International Certificate of ICDL official exam for module 1 (Basic Concepts of Information Technology). ICDL has recently become a de facto standard professional certificate in a wide spectrum of jobs. The system can be used for distance learning/ e-learning or for blended learning approach. It consists of two main modes: the traditional learning mode and the intelligent mode. The traditional learning mode facilitates the learning of concepts by providing full lessons with a fair amount of questions divided between pre lesson quizzes, post lesson quizzes and end of module assessment. The intelligent interactive mode allows the learner to practice concept understanding of the subject matter through means of adaptive self-assessment practices/tests. This is in addition to many other system features including tracking, reporting, assessment/ evaluation tools and some e-communication services and methods.Teachers and students have different interfaces, means of communication, and authorities. The current system consists of nine full lessons with more than 400 questions. An experiment has been conduced to test the system on a random sample of learners to test the effect of the intelligent part over the traditional part on learners learning. The ttest results were impressive and showed that students learning gain on average was 8.1% which is about 3 standard deviations higher when intelligent practiced were involved. The approach is promising and could be extended to cover other subjects and examinations such as SAT, GRE, LSAT, and FE, among others. ItemMulti-Agent Learning of Strategies in Abstract Argumentation Mechanisms(The British University in Dubai (BUiD), 2009-01) Nemer, RamaArgumentation has been studied extensively in the field of Artificial Intelligence, however we know very little about its strategic aspects. This thesis aims to contribute to this general problem by examining the behavior of adaptive self-interested agents, in a multi-agent environment,over repeated encounters using game-theoretic techniques. I extended an existing simulation tool to implement argumentation games and used it to run repeated game experiments using combinations of characteristic argumentation games, adapted from literature, and types of adaptive agents under different conditions.The theme used was that of a court setting whereby there is a judge listening to arguments from different agents. Once all arguments have been presented, the judge must make a ruling: i.e decide which arguments are valid and hence which agents win by presenting them. Agents are assumed to be self-interested and adaptive so they may have conflicting preferences about which arguments they want the judge to accept and they can learn di erent strategies in order to achieve goals that reflect those preferences. The results indicate that the agents use a multitude of different strategies to influence the judge and maximize their payoff , thereby revealing different combinations of arguments with different frequencies, depending on the Nash equilibria of the game, the dominance of the pure strategies and the Pareto e fficiency of the pure strategies in a game. These are dependent on aspects inherent in the argumentation game. While truth revelation was a dominant strategy in some games, interestingly in other cases the agents were able to gain a payoff that is higher than that of all the individual Nash equilibria by playing strategies involving combinations of the Nash equilibria. As for the effect of the learning algorithm on the choice of strategy, the results confirm that WPL is biased toward mixed strategies while GIGA is faster in convergence to pure strategy Nash equilibria. The importance of this kind of work lies in the fact that it combines two aspects of multi-agent systems that have been quite separate to-date: argumentation protocols and multi-agent learning in games. ItemHow Global Coordination Can Be Achieved from Local Coordination in Social Networks(The British University in Dubai (BUiD), 2009-01) Jahedpari, FatemehCoordination in natural and arti cial intelligent systems has attracted the attention of many scientists recently. However, little research has been conducted to understand the relationship between local coordination and global coordination. In this thesis, we are interested in understanding heuristics that humans use in local coordination problems when they attempt to achieve global coordination. Our goal is to use simulation to systematically analyze the inter-play between frequency bias and degree bias and the group's ability to achieve global coordination. Frequency bias refers to situations where people make choices that result in the fewest local conflicts; and the degree bias refers to situations where people avoid conflict with highly connected neighbors. First,we discuss a basic background about networks and di erent parts of an empirical research in coloring problem. After that, a heuristic that models human behavior which biases towards node's degree is described. Then, we explain an improved version of the model which is capable to capture frequency bias.Finally, we investigate the e ects of frequency bias and degree bias together,using our developed model, in di erent network structures. ItemStudying the Effects of Listening to Quran on Human Mood(The British University in Dubai (BUiD), 2009-01) Shaikh, Zeeshan KMany Muslims believe that listening to their holy book Quran, has an effect on their state of mind or mood. Each Surah of Quran emphasizes on a unique topic, warns of wrong doings and provides the correct way of handling a particular situation. A person waiting for a job interview or promotion who often becomes frustrated can listen or read Surahs that may help him feel better. There has been no work done that attempted to study the e ects of Quran on the mood of people. Furthermore, when people are in a tough situation or in a bad mood,they seldom think about listening or reading Quran. In these situations if there is a device with them that can detect their mood and suggest a particular surah, it can help them feel better. This dissertation presents a proof-of-concept mobile application that can run on any Java enabled phone, which takes user's feedback on Surahs, stores the feedback for further analysis and provides a simple suggestion mechanism. ItemSelf-Organization and Multi-Agent Reinforcement Learning for Taxi Dispatch(The British University in Dubai (BUiD), 2009-02) Alshamsi Omran, Aamena Ali AhmedThe taxi dispatch problem involves assigning taxis to callers waiting at different locations. An adjacency-based dispatch system currently in use by a major taxi company divides the city(in which the system operates) into regional dispatch areas. Each area has fixed designated adjacent areas hand-coded by human experts. When a local area does not have vacant cabs,the system chooses an adjacent area to search. However, such fixed, hand-coded adjacency of areas is not always a good indicator because it does not take into consideration frequent changes in tra ffic patterns and road structure. This causes dispatch o fficials to override the system by manually enforcing movement on taxis. In this thesis, I apply two different methods separately to solve the problem: (1) a multiagent self organization technique to dynamically modify the adjacency of dispatch areas (2) a multiagent reinforcement learning method to optimize the dispatch policy for each area. I compare performance of each method with actual data from,and a simulation of, an operational dispatch system. The multiagent self organization technique decreases the total waiting time by up to 25% in comparison with the real system and increases taxi utilization by 20% in comparison with results of the simulation without self-organization. Interestingly, I also discover that human intervention (by either the taxi-dispatch offi cials or the taxi drivers) to manually overcome the limitations of the existing dispatch system can be counterproductive when used with a self-organizing system. Furthermore, the proposed multiagent reinforcement learning method decreases the total waiting time by up to 33.5% in comparison with the real system. ItemThe Effect of Using Advanced Insulation Material on Indoor Temperature(The British University in Dubai (BUiD), 2009-02) Arbabioon, SaharSince UAE’s urban development started two decades ago, the constructions have been influenced by international high technology. As a result, the advanced developments are very different from the local traditional housing which has been built according to the climate. The traditional building materials and components, such masonry and brick walls, have a great capacity to insulate the heat therefore the best possible thermal comfort is achieved during the summer. On the other hand, the modern materials as well as highly glazed surfaces have a little capacity to isolate the heat which causes uncomfortable high temperature during the summer. The purpose of this study was to introduce advanced heat and moisture insulation for UAE hot and humid climate. Studying different type of insulation material such as Phase Change Material, Styropor, Styrodur c, Neopor, Micronal PCM, and EIFS class PB wall and finding the effects of humidity on their thermal storage and their latent heat. The advanced heat and moisture recommended insulation material in this research was Class PB-EIFS panel. EIFS, Exterior Insulation Finish Systems, has been presented in order to reveal the effect of the thickness and the color of the exterior wall which creates more comfort in the interior temperature. Although this material seems more expensive than the normal insulations, but in the real terms a fully glazed building has more initial cost for exterior finishes. By selecting an existing fully glazed building in UAE and applying EIFS with different thickness and colors. The results Ecotect Simulations showed that Class PB EIFS with 290 mm Thickness on beige color exterior finish, not only reduces the annual energy by 10 %, also there was significant of 60% saving on initial cost by removing the glass façade on construction cost. As result the initial cost of buying this EIFS material could be covered in the early years of usage by reducing the annual energy consumption. ItemInvestigations on the integration of Vertical Axis Wind Turbines in High-rise Buildings(The British University in Dubai (BUiD), 2009-04) Helmy, Omar OsamaThe potential of wind energy as a renewable source is widely recognized these days, with wind farms multiplying all around the world. However another application for wind turbine is now gaining interest, the concept of integrating wind power harnessing in the urban environment. The prospective of harnessing energy were it is needed the most and avoiding expensive long distance networks is quiet appealing. This thesis investigates this potential by studying the suitability of different turbine types for urban integration. From the literature review, it seems that VAWTs though much less common of the two main types, is much more suitable for urban integration. A mathematical study was then conducted on four different cities with different wind characteristics to estimate the potential power that can be harnessed by each turbine type in each case. Two modern turbine prototypes were then selected from the two main categories and their power curves was applied to the wind data to calculate the potential power output. Last, the enhancement of the wind energy potential for turbines mounted on high-rise buildings was investigated, through calculating the wind speeds at the respective heights. The second study approach evolved the use of CFD to simulate a number of VAWT integration scenarios in high-rise buildings based on the first part of the research. The wind movement characteristics where observed for the turbine installation location and a calculation was made to estimate the available mass flow rate in each case. Results show a big potential in the integration of VAWT in buildings and promising power gains from increasing the installation height. ItemA Study on Reducing Heat Gains through the use of Bio-Climatic Facades(The British University in Dubai (BUiD), 2009-04) Kambil, Jidesh PadmanabhanFor centuries, humans have built shelters that were bio-climatic and adapted to the region they belonged to. They achieved comfort within their enclosures without the over-dependence on electricity. But since the advent of curtain walls and centralized air-conditioning, we have leaned towards aesthetics at the cost of performance. Pampered by the controlled internal environment, we started to live in isolation from nature, our whole existence became governed by machines and in time our lives have became an extension of the environment we now inhabit. We have also paid the price for our choices. Today the very existence of all life on earth lies on a fragile lifeline of hope. We have used our resources beyond the limit and have poisoned every sphere of life on the planet. It is not certain if there is a way back, but we are left with no more choices, we have only one option. We need to change, now. Buildings have been the surprise villains in the Carbon footprint story and we now know that much of the energy generated by man on earth goes into operating our buildings and its life supporting systems (HVAC). Today, most buildings cannot sustain life within it in the absence of energy to power the ventilation systems. By using sealed facades, we are cutting ourselves entirely from the surrounding environment. But this becomes an even bigger problem when one considers the generous use of glazing in urban architecture especially in some parts of the world like Dubai that are too hot and too bright for such architectural adventures. The overuse of glazing also brings in excess glare and heat, which is often not anticipated or understood when the designer wills a gleaming glazed tower in the middle of a dessert. What then are the solutions if any? Are there any Bio-climatic Solutions to the designer’s dilemma? In this research, the use of ETFE foil cushions as an external surface in a modular double skin façade system is explored. The material offers promising performance figures and could be a sustainable material on many fronts when compared to glass. But first it has to be tested to see whether it can help in reducing heat gains through the façade, which is often the weak point in a building’s defense against the external forces. Simulation models are used to test the performance of ETFE skin with the help of ECOTECT5.5. Heating and Cooling load values will be compared for both glass and ETFE to analyze the effectiveness of both with regard to reducing heat gains. A present worth calculation for ETFE will also be carried out to assess the economic implications of using the material in place of the more conventional glazing. ItemEmpirical Studies in Computer-Mediated Interest-Based Negotiations(The British University in Dubai (BUiD), 2009-05) D'souza, SohanNegotiations in which participants exchange o ers based on their chosen positions can be extended to include dialogue about their interests. Revelation of negotiators' interests allows them to make more acceptable o ers and perhaps propose possible alternative approaches toward each other's interests, both of which may result in mutually and individually beneficial outcomes. However, it can also expose their strategies, and possibly their dependencies on other negotiators toward the achievement of their goals. Revealing this information can leave them vulnerable to extortion or retribution, but it can also be used to gain sympathy or build a relationship of trust and reciprocity.This dissertation studies human behaviour and performance upon introducing options for goal inquiry and revelation into mediated-protocol negotiation scenarios. Empirical studies were conducted by having human players negotiate over an alternating o er protocol and an interest-based bargaining protocol, on a platform specially adapted for this purpose. The analysis of data from these experiments revealed interesting patterns in the human use of goal revelation,and its effects on individual and social outcomes and likelihood of agreement. The design of the experiments and the development of the experimentation platform lay the groundwork for the further study of goal revelation in mediated negotiations with humans. ItemThe effects of organizational culture on risk management during software development(The British University in Dubai (BUiD), 2009-06) Verma, CharuThe inevitable challenge of time, schedule, cost and scope in software projects has been a matter of concern even for powerful names like Microsoft and IBM. No matter how well equipped an establishment is, these projects come entrapped in risks. However, dealing proactively with these risks could truly be rewarding. There are several books, methodologies and tools which attempt to deal with Software Project Risk Management; nevertheless there is always another side to solving a problem, which the research is going to explore. The research is centered on the subject of studying whether it is the methodology or the work culture or both, which is responsible for the success or the failure of a software project. The subject of “Cultural Issues Impacting Risk Management” during software project development has been explored by very few authors with a narrow coverage. The main aim of this study is to obtain an understanding of key cultural barriers to effective Software Project Risk Management. The study begins with identifying the software project risks and risk behavior during various Software Development Life Cycles, followed by studying the means of culture emergence in an organization and how it influences the software development process. Moreover, the initial studies are researched further by means of interviews, surveys and case studies. The outcome of which is used to develop a support structure to aid organizations identify and assess Software Project Risks, by making it an integral part of the organizational conduct. ItemDesign for outdoor in a hot & dry climate: a study of outdoor thermal comfort in Dubai, UAE(The British University in Dubai (BUiD), 2009-06) Fabros, Malaya V.With the growing interest on sustainability, design consideration for thermal comfort in the outdoors is seen as an important factor enhancing the quality of life in the urban setting. The topic has received significant interest and several studies have been made in mostly temperate and tropical climates. However, not much investigation into the matter has been done in hot-arid climates characteristic to that of the middle-eastern countries. The study then aimed to understand the relationships between the several factors (air temperature, solar radiation, relative humidity, wind speed, clothing and activity) affecting thermal comfort, determine the actual comfort zone for Dubai UAE through field measurements and interview surveys, and recommend design considerations to achieve thermal comfort. The findings of the study show that majority of the sample population in Dubai reported overall thermal comfort for the three seasons observed. Solar radiation has most direct influence on thermal comfort outdoors thus it is recommended that shading be of primary consideration during summer. It was also found that relative humidity is an amplifying factor for air temperature. Wind should be accounted for its cooling effect thus high wind speeds are encouraged during summer while protection from this must be provided during winter. Contrary to the common notion that middle eastern climate is very harsh and that thermal comfort could only be achieved in a controlled indoor environment, the study shows that with proper design consideration of the findings in the study, it is possible to achieve thermal comfort for outdoors in Dubai for longer periods of the year. ItemA Modified Double Skin Façade for the Desert Climate Integrated with Evaporative Cooling Spray(The British University in Dubai (BUiD), 2009-06) Ventura, Redentor G.Existing literature on double-skin facades is reviewed, including classifications and its transferability to hot and humid climates. The analysis led to evaporative cooling spray, where objectives are drawn to quantify its benefit. For research tools, selection process for appropriate software is undergone followed by training to achieve proficiency. Basic software validation is conducted using an actual building consumption comparison. The simulation parameters are established by changing a Prototype configuration to determine its energy consumption, mass air flow and CFD patterns. Governing equations are explained and utilized for manual calculations together with the Psychrometric chart that plots values against various air conditions. Simulation results are post processed and integrated into the equation to achieve values not covered in the software capability. Results show 5% energy consumption savings utilizing double skin facades. There are little energy savings with the tested variables in configuration. Air mass flow is generally improved by increase of width and height while orientation air flow results vary. Using the proposed spray on the double skin façade, Prototype day design savings on an office building is improved by 3% while a residential building could benefit from 50 – 90% reduction. The dissertation concludes with limitations and suggestions for future. studies.