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2015

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Articles 3601 - 3630 of 7527

Full-Text Articles in Engineering

Students' Task Interpretation And Conceptual Understanding In Electronics Laboratory Work, Presentacion Rivera-Reyes May 2015

Students' Task Interpretation And Conceptual Understanding In Electronics Laboratory Work, Presentacion Rivera-Reyes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Students’ interpretation of an assigned task is a key determinant of setting goals, choosing strategies to accomplish those goals, monitoring, and self-evaluating outcomes. Laboratory activities, including worksheets, quizzes, and other assignment are designed to improve the understanding of concepts taught in the classroom. The main concern of many laboratory students is simply completion of the task because it is critical to their success. Three objectives were proposed in this study, to investigate: (1) the students’ interpretation of the task before and after the completion of the laboratory activity, (2) the interpretation of the task differs between high- and low- coregulated …


Microscopic Modeling Of Crowds Involving Individuals With Physical Disability: Exploring Social Force Interaction, Daniel S. Stuart May 2015

Microscopic Modeling Of Crowds Involving Individuals With Physical Disability: Exploring Social Force Interaction, Daniel S. Stuart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nearly one quarter of a population is affected by a disability which influences crowd evacuation. Emergencies such as stampede or crowd crush can occur during evacuations. While research has investigated crowd evacuation, little has been researched involving individuals with disabilities. There is a need to understand and model individuals with disabilities in their interaction and how it impacts crowd movement. This dissertation creates a video tracking system to study heterogeneous crowds with individuals with disabilities towards conducting crowd experiments. A large-scale crowd experiment is conducted and the results are analyzed through a developed analysis graphical user interface. Preliminary results of …


Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photo Catalytic Applications, Haya Abdel Ra’Ouf Ahmed Ra’Ouf Ahmed May 2015

Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photo Catalytic Applications, Haya Abdel Ra’Ouf Ahmed Ra’Ouf Ahmed

Theses

The goal of this work was to improve the performance of TiO2 nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO2 nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO2 nanomaterials. In this work, we have prepared Cu-doped TiO2 and Ag-doped TiO2 nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO2 catalyst was prepared by the sol-gel method while the Cu-doped …


Spectrum Sharing In Cognitive Radio Networks With Quality Of Service Awareness, Nadir Hussin Sulieman Adam May 2015

Spectrum Sharing In Cognitive Radio Networks With Quality Of Service Awareness, Nadir Hussin Sulieman Adam

Theses

The goal of this thesis is to study performance of cognitive radio networks in terms of total spectrum utilization and throughput of secondary networks under perfect and imperfect sensing for Additive White Gaussian Noise (AWGN) and fading channels. The effect of imperfect sensing was studied by applying non-collaborative and collaborative sensing techniques using energy detecting and square law combining techniques, respectively. Spectrum allocation for heterogeneous networks in cognitive radio networks was discussed and a new sharing algorithm that guarantee Quality of Service (QoS) for different secondary users’ applications was proposed. The throughput degradation of secondary users due to the activities …


Structural Response Of Flexure-Deficient Reinforced Concrete Continuous Slabs Strengthened With Composites, Jwan Ahmad Al Khalil May 2015

Structural Response Of Flexure-Deficient Reinforced Concrete Continuous Slabs Strengthened With Composites, Jwan Ahmad Al Khalil

Theses

Accidental reduction in the amount of steel in continuous reinforced concrete (RC) floor slabs is a typical problem that might occur due to an error in design, unclear drawings, or overlooked verification of reinforcement prior to concrete casting. Existence of such deficiencies would compromise the load capacity and serviceability of RC floor slabs. This research examines the effectiveness of using fiber-reinforced polymers (FRP) to improve the structural response of flexure-deficient continuous RC slab strips. The study comprised experimental testing and finite element (FE) modeling. Sixteen two-span RC slab strips, 400 x 125 x 3800 mm each, were tested. Test parameters …


Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photocatalytic Applications, Haya Abdel Ra'ouf Ahmed May 2015

Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photocatalytic Applications, Haya Abdel Ra'ouf Ahmed

Theses

The goal of this work was to improve the performance of TiO2 nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO2 nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO2 nanomaterials. In this work, we have prepared Cu-doped TiO2 nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO2 catalyst was prepared by the sol-gel method while …


Capacity Models For Multilane Roundabouts And Their Evaluation Using Microscopic Simulation Models, Mohamad A. Shrayteh May 2015

Capacity Models For Multilane Roundabouts And Their Evaluation Using Microscopic Simulation Models, Mohamad A. Shrayteh

Theses

Compared to previous versions of the manual, the Highway Capacity Manual 2010 has provided more comprehensive capacity models for single and multilane roundabouts. The Highway Capacity Manual 2010 multilane roundabout capacity models are limited to two-by-two lanes, that is, two entry lanes and two circulating lanes. These capacity models are not valid for the three-by-three–lane roundabouts (three entry lanes and three circulating lanes) due to different traffic flow characteristics and features. This limitation of the Highway Capacity Manual 2010 model is also clearly mentioned in the manual. In this research, capacity models and curves were developed for three-by-three–lane roundabouts. More …


Potential Of Greywater Reuse And Its Effects On Potable Water Demand Management And Downstream Sewer Network, Muhammad Ashfaque Rajput Abdul Hameed May 2015

Potential Of Greywater Reuse And Its Effects On Potable Water Demand Management And Downstream Sewer Network, Muhammad Ashfaque Rajput Abdul Hameed

Theses

The UAE’s water demand is rapidly increasing because of population growth, infrastructure development, expansion of agricultural practices, and desert greening policies. These circumstances force the country to depend on expansive desalinated water and made the country the second-largest desalination water producer in the world. It is essential to reduce the current water consumption rates by using efficient methods and conservation techniques. Greywater reuse is an effective and promising alternative to cope with this challenge. The study aimed to reduce water consumption in the Emirate of Abu Dhabi by investigating the potential of greywater reuse. A field survey was carried out …


Ambient Rendezvous: Energy Efficient Neighbor Discovery Via Acoustic Sensing, Keyu Wang, Zheng Yang, Zimu Zhou, Yunhao Liu, Lionel M. Ni May 2015

Ambient Rendezvous: Energy Efficient Neighbor Discovery Via Acoustic Sensing, Keyu Wang, Zheng Yang, Zimu Zhou, Yunhao Liu, Lionel M. Ni

Research Collection School Of Computing and Information Systems

The continual proliferation of mobile devices has stimulated the development of opportunistic encounter-based networking and has spurred a myriad of proximity-based mobile applications. A primary cornerstone of such applications is to discover neighboring devices effectively and efficiently. Despite extensive protocol optimization, current neighbor discovery modalities mainly rely on radio interfaces, whose energy and wake up delay required to initiate, configure and operate these protocols hamper practical applicability. Unlike conventional schemes that actively emit radio tones, we exploit ubiquitous audio events to discover neighbors passively. The rationale is that spatially adjacent neighbors tend to share similar ambient acoustic environments. We propose …


Phaseu: Real-Time Los Identification With Wifi, Chenshu Wu, Zheng Yang, Zimu Zhou, Kun Qian, Yunhao Liu, Mingyan Liu May 2015

Phaseu: Real-Time Los Identification With Wifi, Chenshu Wu, Zheng Yang, Zimu Zhou, Kun Qian, Yunhao Liu, Mingyan Liu

Research Collection School Of Computing and Information Systems

WiFi technology has fostered numerous mobile computing applications, such as adaptive communication, finegrained localization, gesture recognition, etc., which often achieve better performance or rely on the availability of Line-Of-Sight (LOS) signal propagation. Thus the awareness of LOS and NonLine-Of-Sight (NLOS) plays as a key enabler for them. Realtime LOS identification on commodity WiFi devices, however, is challenging due to limited bandwidth of WiFi and resulting coarse multipath resolution. In this work, we explore and exploit the phase feature of PHY layer information, harnessing both space diversity with antenna elements and frequency diversity with OFDM subcarriers. On this basis, we propose …


Mining Patterns Of Unsatisfiable Constraints To Detect Infeasible Paths, Sun Ding, Hee Beng Kuan Tan, Lwin Khin Shar May 2015

Mining Patterns Of Unsatisfiable Constraints To Detect Infeasible Paths, Sun Ding, Hee Beng Kuan Tan, Lwin Khin Shar

Research Collection School Of Computing and Information Systems

Detection of infeasible paths is required in many areas including test coverage analysis, test case generation, security vulnerability analysis, etc. Existing approaches typically use static analysis coupled with symbolic evaluation, heuristics, or path-pattern analysis. This paper is related to these approaches but with a different objective. It is to analyze code of real systems to build patterns of unsatisfiable constraints in infeasible paths. The resulting patterns can be used to detect infeasible paths without the use of constraint solver and evaluation of function calls involved, thus improving scalability. The patterns can be built gradually. Evaluation of the proposed approach shows …


Matchmaking Game Players On Public Transport, Nairan Zhang, Youngki Lee, Rajesh Krishna Balan May 2015

Matchmaking Game Players On Public Transport, Nairan Zhang, Youngki Lee, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

This paper extends our recent work, called GameOn, which presented a system for allowing public transport commuters to engage in multiplayer games with fellow commuters traveling on the same bus or train. An important challenge for GameOn is to group players with reliable connections into the same game. In this case, the meaning of reliability has two dimensions. First, the network connectivity (TCP, UDP etc.) should be robust. Second, the players should be collocated with each other for a sufficiently long duration so that a game session will not be terminated by players leaving the public transport modality such as …


Near-Optimal Decentralized Power Supply Restoration In Smart Grids, Pritee Agrawal, Akshat Kumar, Pradeep Varakantham May 2015

Near-Optimal Decentralized Power Supply Restoration In Smart Grids, Pritee Agrawal, Akshat Kumar, Pradeep Varakantham

Research Collection School Of Computing and Information Systems

Next generation of smart grids face a number of challenges including co-generation from intermittent renewable power sources, a shift away from monolithic control due to increased market deregulation, and robust operation in the face of disasters. Such heterogeneous nature and high operational readiness requirement of smart grids necessitates decentralized control for critical tasks such as power supply restoration (PSR) after line failures. We present a novel multiagent system based approach for PSR using Lagrangian dual decomposition. Our approach works on general graphs, provides provable quality-bounds and requires only local message-passing among different connected sub-regions of a smart grid, enabling decentralized …


Predicting Bundles Of Spatial Locations From Learning Revealed Preference Data, Truc Viet Le, Siyuan Liu, Hoong Chuin Lau, Ramayya Krishnan May 2015

Predicting Bundles Of Spatial Locations From Learning Revealed Preference Data, Truc Viet Le, Siyuan Liu, Hoong Chuin Lau, Ramayya Krishnan

Research Collection School Of Computing and Information Systems

We propose the problem of predicting a bundle of goods, where the goods considered is a set of spatial locations that an agent wishes to visit. This typically arises in the tourism setting where attractions can often be bundled and sold as a package to visitors. While the problem of predicting future locations given the current and past trajectories is well-established, we take a radical approach by looking at it from an economic point of view. We view an agent's past trajectories as revealed preference (RP) data, where the choice of locations is a solution to an optimisation problem according …


Solving Multi-Vehicle Profitable Tour Problem Via Knowledge Adoption In Evolutionary Bi-Level Programming, Stephanus Daniel Handoko, Abhishek Gupta, Chen Kim Heng, Hoong Chuin Lau, Yew Soon Ong, Puay Siew Tan May 2015

Solving Multi-Vehicle Profitable Tour Problem Via Knowledge Adoption In Evolutionary Bi-Level Programming, Stephanus Daniel Handoko, Abhishek Gupta, Chen Kim Heng, Hoong Chuin Lau, Yew Soon Ong, Puay Siew Tan

Research Collection School Of Computing and Information Systems

Profitable tour problem (PTP) belongs to the class of vehicle routing problem (VRP) with profits seeking to maximize the difference between the total collected profit and the total cost incurred. Traditionally, PTP involves single vehicle. In this paper, we consider PTP with multiple vehicles. Unlike the classical VRP that seeks to serve all customers, PTP involves the strategic-level customer selection so as to maximize the total collected profit and the operational-level route optimization to minimize the total cost incurred. Therefore, PTP is essentially the knapsack problem at the strategic level with VRP at the operational level. That means the evolutionary …


Measuring Centralities For Transportation Networks Beyond Structures, Yew-Yih Cheng, Lee Ka Wei, Roy, Ee-Peng Lim, Feida Zhu May 2015

Measuring Centralities For Transportation Networks Beyond Structures, Yew-Yih Cheng, Lee Ka Wei, Roy, Ee-Peng Lim, Feida Zhu

Research Collection School Of Computing and Information Systems

In an urban city, its transportation network supports efficient flow of people between different parts of the city. Failures in the network can cause major disruptions to commuter and business activities which can result in both significant economic and time losses. In this paper, we investigate the use of centrality measures to determine critical nodes in a transportation network so as to improve the design of the network as well as to devise plans for coping with the network failures. Most centrality measures in social network analysis research unfortunately consider only topological structure of the network and are oblivious of …


System Wide Trust Contagion Effect, Rian M. Mehta May 2015

System Wide Trust Contagion Effect, Rian M. Mehta

Theses and Dissertations

Trust is integral in any service industry, especially in the consumeroriented field of aviation. The first step of this research is the reorganization of the importance of trust. To understand its importance on the industry, it is necessary to study trust and its effects in depth. The purpose of this study is to further explore the relationship between the passengers’ trust in automation, and trust in humans. Oftentimes, when automation fails, some human is responsible for harboring the blame. The theory of System Wide Trust (SWT) has only been recently developed, but its effect on the field of aviation is …


Consumers’ Trust In Pilots Based On Pilot’S Preference For Use Of Breathalyzer In The Cockpit, Katie Marie Reid May 2015

Consumers’ Trust In Pilots Based On Pilot’S Preference For Use Of Breathalyzer In The Cockpit, Katie Marie Reid

Theses and Dissertations

Trust has been studied across disciplines for years, with the focus looking at trust between individuals, between individuals and organizations, and between organizations (Lee & See, 2004). Establishing trust between people has been an issue for decades (Simpson, 2011), but defining it has proved difficult as well. Within the aviation industry, there has been a lack of research exploring how trust is affected from the consumer’s or passenger’s perspective. Aviation is one of the major forms of transportation in today’s culture, and understanding consumers’ trust is important for safety and economic reasons. The current study will use a 5-point Likert-type …


Formal Specification And Refinement Of The Navigation Tasks Of Autonomous Robots, Eman Rabiah May 2015

Formal Specification And Refinement Of The Navigation Tasks Of Autonomous Robots, Eman Rabiah

Theses

Autonomous robots are hybrid systems whose role in our daily life is becoming increasingly critical. They are tasked with various activities requiring reliability, safety, and correctness of their software-controlled behavior. Formal methods have been proved effective in addressing development issues associated with these software qualities. However, even though autonomous robot navigation is a primordial function, there is no research dealing with enhancing reliability of the navigation algorithms. Thus, our focus is to investigate this type of algorithms, and specifically path planning, a fundamental and critical functionality supporting autonomy. We formally address the issue of enhancing reliability of the widely-used A* …


Direct: A Scalable Approach For Route Guidance In Selfish Orienteering Problems, Pradeep Varakantham, Hala Mostafa, Na Fu, Hoong Chuin Lau May 2015

Direct: A Scalable Approach For Route Guidance In Selfish Orienteering Problems, Pradeep Varakantham, Hala Mostafa, Na Fu, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We address the problem of crowd congestion at venues like theme parks, museums and world expos by providing route guidance to multiple selfish users (with budget constraints) moving through the venue simultaneously. To represent these settings, we introduce the Selfish Orienteering Problem (SeOP) that combines two well studied problems from literature, namely Orienteering Problem (OP) and Selfish Routing (SR). OP is a single agent routing problem where the goal is to minimize latency (or maximize reward) in traversing a subset of nodes while respecting budget constraints. SR is a game between selfish agents looking for minimum latency routes from source …


Multi-Agent Task Assignment For Mobile Crowdsourcing Under Trajectory Uncertainties, Cen Chen, Shih-Fen Cheng, Hoong Chuin Lau, Archan Misra May 2015

Multi-Agent Task Assignment For Mobile Crowdsourcing Under Trajectory Uncertainties, Cen Chen, Shih-Fen Cheng, Hoong Chuin Lau, Archan Misra

Research Collection School Of Computing and Information Systems

In this work, we investigate the problem of mobile crowdsourcing, where workers are financially motivated to perform location-based tasks physically. Unlike current industry practice that relies on workers to manually browse and filter tasks to perform, we intend to automatically make task recommendations based on workers' historical trajectories and desired time budgets. However, predicting workers' trajectories is inevitably faced with uncertainties, as no one will take exactly the same route every day; yet such uncertainties are oftentimes abstracted away in the known literature. In this work, we depart from the deterministic modeling and study the stochastic task recommendation problem where …


Potential Of Greywater Reuse And Its Effects On Potable Water Demand Management And Downstream Sewer Network, Muhammad Ashfaque Rajput Abdul Hameed May 2015

Potential Of Greywater Reuse And Its Effects On Potable Water Demand Management And Downstream Sewer Network, Muhammad Ashfaque Rajput Abdul Hameed

Theses

The UAE’s water demand is rapidly increasing because of population growth, infrastructure development, expansion of agricultural practices and for the desert greening policies. These circumstances force the country to depend on expansive desalinated water and made the country second largest desalination water producer in the world. It is essential to reduce the current water consumption rates by using efficient methods and conservation techniques. Greywater reuse is an effective and promising alternate to cope with this challenge. The study aimed to reduce the water consumption in the Emirate of Abu Dhabi by investigating the potential of greywater reuse. A field survey …


Circuit Design For The Development Of A Non-Contact Ecg System, Nathan Blanchard May 2015

Circuit Design For The Development Of A Non-Contact Ecg System, Nathan Blanchard

Honors Capstones

No abstract provided.


Characterization Of Low Density Intracranial Lesions Using Dual-Energy Computed To Mography, Jessica L. Nute May 2015

Characterization Of Low Density Intracranial Lesions Using Dual-Energy Computed To Mography, Jessica L. Nute

Dissertations and Theses (Open Access)

Calcific and hemorrhagic foci of susceptibility are frequently encountered on routine brain MR studies. Both etiologies cause variations in local magnetic field strength, leading to dark regions on the MR images that cannot be classified. Single-energy CT (SECT) can be used to identify lesions with attenuation over 100 HU as calcific, however lesions with lower attenuation cannot be reliably identified. While calcific lesions are unlikely to cause harm, hemorrhagic lesions carry a risk of subsequent intracranial bleeding; as such, identification of hemorrhage is vital in preventing the inappropriate use of anticoagulant medications in patients with hemorrhagic lesions.

Given there currently …


Selection Methods For Genetically-Modified T Cells: In Support Of Translational Therapy, David Rushworth May 2015

Selection Methods For Genetically-Modified T Cells: In Support Of Translational Therapy, David Rushworth

Dissertations and Theses (Open Access)

T cells are blood cells which organize the immune system of the host. These cells are necessary for the host to respond appropriately to threats from foreign organisms and cancerous growth. However, in the case of certain infections and cancer, T cells are unable to respond appropriately to a threat and establish immunity. This leads to disease when the infection or cancer is not sufficiently eliminated. On the other hand, T cells can lack tolerance for healthy tissue and perceive healthy tissue as infected. The ensuing over-reactive immune response also leads to disease. A delicate balance must exist between immunity …


A Multi-Objective Optimization Method For Maximizing The Value Of System Evolvability Under Uncertainty, Jason Daniel Watson May 2015

A Multi-Objective Optimization Method For Maximizing The Value Of System Evolvability Under Uncertainty, Jason Daniel Watson

Theses and Dissertations

System evolvability is vital to the longevity of large-scale complex engineered systems. The need for evolvability in complex systems is a result of their long service lives, rapid advances to their integrated technologies, unforeseen operating conditions, and emerging system requirements. In recent years, quantifiable metrics have been introduced for measuring the evolvability of complex systems based on the amount of excess capability in the system. These metrics have opened opportunities for optimization of systems with evolvability as an objective. However, there are several aspects of such an optimization that require further consideration. For example, there is a trade-off between the …


Smart Carabiner, Craig Manning May 2015

Smart Carabiner, Craig Manning

Undergraduate Honors Capstone Projects

Users of common climbing safety equipment rarely understand exactly the loads and forces they are exerting on the equipment at a given time. All climbing equipment comes with a certified safety rating for the amount of force, in kilonewtons, that particular piece of equipment can take. Unfortunately, calculating dynamic load strain on-the-fly is nearly impossible. There needs to be a reliable, easy way of knowing exactly what load is being placed on a piece of equipment at any given point of time.


Computational Modeling Of Alternating Current Potential Drop Measurement For Crack Detection Of Multi-Functional Ceramic Coated Structures, Simha Sandeep Rao May 2015

Computational Modeling Of Alternating Current Potential Drop Measurement For Crack Detection Of Multi-Functional Ceramic Coated Structures, Simha Sandeep Rao

All Theses

Non-destructive testing and evaluation (NDT&E) is a set of techniques commonly used to evaluate a material for the presence of any flaws without actually degrading the material itself. The Alternating Current Potential Drop (ACPD) test method is one of the NDT surface methods used to determine the electrically insulating defects beneath the surface by injection of currents in the structure and measurement of the resulting voltage difference between two or more points on the surface. The presence of defects generally increases the resistance of the structure and hence causes the drop of measured voltage. The inversion of this data can …


Benefits Of A State Driveway Database With Qualitative And Quantitative Crash Analysis, Andrew Bryant Stokes May 2015

Benefits Of A State Driveway Database With Qualitative And Quantitative Crash Analysis, Andrew Bryant Stokes

All Theses

The primary goal of this research is to show how a fully developed driveway database will improve access management practices resulting in a reduction in crashes, injuries, and fatalities on our roadways. The results of this thesis highlight a close relationship between driveway characteristics and the incidence of crashes. Thus, it is critical to be proactive in enforcing access management strategies and policies that are designed to enhance driveway safety without compromising the economic vitality of land use along roads. The analysis identified several significant independent variables that influence crash rates either positively or negatively. The data driven approach to …


Eye Tracking Consumer Purchase Behavior Within Physical And Virtual Environments, David Andrew Stone May 2015

Eye Tracking Consumer Purchase Behavior Within Physical And Virtual Environments, David Andrew Stone

All Theses

Understanding how consumers observe and make purchase decisions within a retail context is now both accessible and efficient through the process of eye tracking. Eye tracking package design aesthetics helps us understand and predict what consumers are looking at, and how likely a package might be selected. Typically, this research is conducted in an immersive retail setting where consumers can shop as they would in a normal store-shopping context. A store is stocked with products where a participant in the study shops throughout while wearing an eye tracker to gather data on what their attention fixates on within a given …