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2011

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Articles 4111 - 4140 of 5801

Full-Text Articles in Engineering

A Unified Model-Based Fault Diagnosis Scheme For Nonlinear Discrete-Time Systems With Additive And Multiplicative Faults, Hasan Ferdowsi, Sarangapani Jagannathan Jan 2011

A Unified Model-Based Fault Diagnosis Scheme For Nonlinear Discrete-Time Systems With Additive And Multiplicative Faults, Hasan Ferdowsi, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel model-Based fault diagnosis scheme is proposed for a class of uncertain nonlinear discrete-time systems which can be subjected to both additive and multiplicative faults. Faults are detected by using a novel (FD) observer consisting of two online approximators in discrete-time (OLAD) and a robust adaptive term. Upon detection, a fault diagnosis scheme is introduced to determine the fault type by monitoring the input residual generated via the first OLAD output. Then the appropriate OLAD is included in the observer while the other OLAD is switched off. Next, by using both the parameter update law of …


Stochastic Optimal Control Design For Nonlinear Networked Control System Via Neuro Dynamic Programming Using Input-Output Measurements, Hao Xu, Sarangapani Jagannathan Jan 2011

Stochastic Optimal Control Design For Nonlinear Networked Control System Via Neuro Dynamic Programming Using Input-Output Measurements, Hao Xu, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Neuro dynamic programming (NDP) techniques for optimal control of nonlinear network control system (NNCS) are not addressed in the literature. Therefore, in this paper, a novel NNCS representation incorporating the unknown system uncertainties and network imperfections is introduced first by using input and output measurements. Then, an online neural network (NN) identifier is introduced to estimate the control coefficient matrix. Subsequently, the critic NN and action NN are employed along with the NN identifier to determine the forward-in-time, time-Based stochastic optimal control of NNCS without using value and policy iterations. Instead, value function and control inputs are updated at every …


Comparison Of Brain Activity In The Prefrontal Cortex During Digit Span Task Between Student Veterans With Post Traumatic Stress Disorder And Controls Using Functional Near Infrared Spectroscopy, Bejoy Mathai Jan 2011

Comparison Of Brain Activity In The Prefrontal Cortex During Digit Span Task Between Student Veterans With Post Traumatic Stress Disorder And Controls Using Functional Near Infrared Spectroscopy, Bejoy Mathai

Bioengineering Theses - Archive

Near Infrared Spectroscopy (NIRS) is an optical non-invasive imaging technique which makes use of infrared light at particular wavelengths to measure the changes in concentrations of oxygenated blood haemoglobin (HbO) as well as the deoxygenated blood haemoglobin (HbR). Making use of this technique to acquire measurements during different functional activities subcategorises it into the novel and fast developing field of Functional Near Infrared Spectroscopy (fNIRS). In my study I have made use of this novel imaging technique to study the pre-frontal cortex while the subject performs the functional task of digit span task consisting of the forward digit span and …


Flexural Behavior Of Steel Fiber Reinforced Prestressed Concrete Beams And Double Punch Test For Fiber Reinforced Concrete, Netra Bahadur Karki Jan 2011

Flexural Behavior Of Steel Fiber Reinforced Prestressed Concrete Beams And Double Punch Test For Fiber Reinforced Concrete, Netra Bahadur Karki

Civil Engineering Dissertations - Archive

Steel fibers have widely been used in the past to reinforce brittle materials in many nonstructural applications such as pavement, tunneling lining, etc. On the basis of numerous previous studies, ACI 318-11 [2011] has recently accepted steel fiber as a minimum shear reinforcement replacement with minimum 0.75% volume fraction for both reinforced concrete and prestressed concrete members. However, not much previous research has talked about the flexural behavior of fiber reinforced concrete (FRC). As per ACI 318-11 for tension-controlled sections, the net tensile strains in the outermost layer of steel, εt, should be greater than or equal to 0.005 and …


Evaluation Of Training Needs For Building Information Modeling (Bim), German Pena Jan 2011

Evaluation Of Training Needs For Building Information Modeling (Bim), German Pena

Civil Engineering Theses - Archive

The basic premise of Building Information Modeling (BIM) is to use and share the digital model of a project as a source of information for all participants, in order to simulate and analyze potential problems during the project's life-cycle, from conception to operation. BIM is a relatively new technology praised by all participants in the Architecture-Engineering-Construction (AEC) industry for its innovative tools, and the promise of a high return of investment and productivity increase. The construction industry experimented little growth in productivity in the last decades, and is heavily relying on technology rather than intense labor in order to boost …


Effect Of Pavement Type On Fuel Consumption In City Driving, Palinee Sumitsawan Jan 2011

Effect Of Pavement Type On Fuel Consumption In City Driving, Palinee Sumitsawan

Civil Engineering Dissertations - Archive

Vehicular fuel consumption and emissions are two increasingly important measures of effectiveness of sustainable transportation systems, particularly considering that mobile sources in the U.S. account for the largest consumption of energy and generation of air pollution. Improving the energy efficiency of the transportation sector including improving vehicle shape, weight, engine size, and tire quality could play a vital role in reducing fuel consumption and exhaust gas emissions. Pavement surface type and other surface characteristics such as skid resistance and roughness affect vehicular fuel consumption. The main objective of this study has been to investigate any differences that might exist in …


Development Of A Model Of Productivity For Horizontal Directional Drilling (Hdd), Mohmd Sarireh Jan 2011

Development Of A Model Of Productivity For Horizontal Directional Drilling (Hdd), Mohmd Sarireh

Civil Engineering Dissertations - Archive

Horizontal Directional Drilling (HDD) is a growing method for installation of pipes in urban areas and where ever trenching is impossible or undesirable; such as in crossing rivers, lakes, and railways, and special areas such as airports. This technique utilizes downhole cutting heads to create a pilot borehole before it is enlarged with back reamers to allow pulling back of a product pipe. The utilization of HDD for the installation of underground infrastructure (i.e., water, oil and gas pipes, telecommunication, power conduits, in some cases gravity pipes, and so on), has shown a rapid growth compared to other trenchless technologies. …


Impact Of Transit-Oriented Infrastructure Investments On Property Valuations, Francis Amodu Smith Jan 2011

Impact Of Transit-Oriented Infrastructure Investments On Property Valuations, Francis Amodu Smith

Civil Engineering Dissertations - Archive

The population explosion of the second half of the last century brought about increased human activity. Much of the attendant increased access to activities has been facilitated by the incredible technological advances in the automobile, which depends almost entirely on fossil fuels. Supplies of fossil fuel are limited and the automobile has led to urban sprawl, traffic congestion, and reduced quality to life in cities (1). This type of development is unsustainable. Transit-oriented development (TOD) is one of the neo-urbanism response instruments. The question is: "How well do these urban forms perform in North-Central Texas? In response, this study has …


Nano-Modified Cement Composites And Its Applicability As Concrete Repair Material, Tanvir Manzur Jan 2011

Nano-Modified Cement Composites And Its Applicability As Concrete Repair Material, Tanvir Manzur

Civil Engineering Dissertations - Archive

Nanotechnology or Nano-science, considered the forth industrial revolution, has received considerable attention in the past decade. The physical properties of a nano-scaled material are entirely different than that of bulk materials. With the emerging nanotechnology, one can build material block atom by atom. Therefore, through nanotechnology it is possible to enhance and control the physical properties of materials to a great extent. Composites such as concrete materials have very high strength and Young's modulus but relatively low toughness and ductility due to their covalent bonding between atoms and lacking of slip systems in the crystal structures. However, the strength and …


Multivariate Adaptive Regression Spline Based Framework For Statistically Parsimonious Adaptive Dynamic Programming, Subrat Sahu Jan 2011

Multivariate Adaptive Regression Spline Based Framework For Statistically Parsimonious Adaptive Dynamic Programming, Subrat Sahu

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Central to Dynamic Programming (DP) is the `cost-to-go' or `future value' function, which is obtained via actually solving the Bellman's equation and central to Approximate Dynamic Programming (ADP) is the use of an approximation of the future value function. The exact DP algorithm seeks to compute and store a table consisting of one cost-to-go value for each point in the state space and its usefulness is limited by the curse of dimensionality, which renders the methodology computationally intractable in the face of real life problems with high dimensional state space and in the face of continuous state variables. ADP methodology …


A Matrix Formulation For The Moment Distribution Method Applied To Continuous Beams, Arlindo Pires Lopes, Adriana Santos, Rogério Coelho Lopes Jan 2011

A Matrix Formulation For The Moment Distribution Method Applied To Continuous Beams, Arlindo Pires Lopes, Adriana Santos, Rogério Coelho Lopes

Civil and Environmental Engineering Faculty Publications and Presentations

The Moment Distribution Method is a quite powerful hand method of structural analysis, in which the solution is obtained iteratively without even formulating the equations for the unknowns. It was formulated by Professor Cross in an era where computer facilities were not available to solve frame problems that normally require the solution of simultaneous algebraic equations. Its relevance today, in the era of personal computers, is in its insight on how a structure reacts to applied loads by rotating its nodes and thus distributing the loads in the form of member-end moments. Such an insight is the foundation of the …


Nano-Engineered High-Performance Magneto-Optic Garnet Materials, Mohammad Nur-E-Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh Jan 2011

Nano-Engineered High-Performance Magneto-Optic Garnet Materials, Mohammad Nur-E-Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh

ECU Presentations

No abstract provided.


Calorific Values Of Building Materials And Their Effect On The Structural Environment, Graham Doyle Jan 2011

Calorific Values Of Building Materials And Their Effect On The Structural Environment, Graham Doyle

Theses

As materials are seen to be a distinct source of fire and to avoid the destructive effects of fire to people and the environment, there is certainly a need for an assessment of building materials, internal finishes and contents to be conducted in a fire engineering context. This report examines the effect of these materials on the structural environment with a view of ultimately determining compartmental fire loads.

Research has shown that there is a significant lack of information available in regards to the calorific values of materials, and in particular building materials. In addition, material calorific values and generic …


A Finite Element Study Of Precast Prestressed Concrete Circular Tanks Subject To Elevated Temperatures, Michael Minehane Jan 2011

A Finite Element Study Of Precast Prestressed Concrete Circular Tanks Subject To Elevated Temperatures, Michael Minehane

Theses

The current study investigates the influence of heated water storage, upward of 95°C, on precast prestressed concrete circular tanks. Modem design standards for liquid- retaining concrete structures stipulate that thermal effects are to be considered for the serviceability limit state. They are also to be considered for the ultimate limit state when deemed significant. The standards, however, do not provide guidance for the analysis of such effects. Research in this area is also limited and exclusively concerned with ambient thermal conditions, with a maximum temperature of 30 °C in any instance.

A finite element study incorporating thermo-mechanical coupling investigates the …


Semi-Automatic Management Of Knowledge Bases Using Formal Ontologies, Andreas Textor Jan 2011

Semi-Automatic Management Of Knowledge Bases Using Formal Ontologies, Andreas Textor

Theses

This thesis presents an approach that deals with the ever-growing amount of data in knowledge bases, especially concerning knowledge interoperability and formal representation of domain knowledge. There arc multiple issues that must be addressed with current systems. A multitude of different formats, sources and tools exist in a domain, and it is desirable to develop their use further towards a standardised environment. Such an environment should support both the representation and processing of data from this domain, and the connection to other domains, where necessary. In order to manage large amounts of data, it should be possible to perform whatever …


Design Of A Centralised Anaerobic Digestion Plant In Ireland., Diarmuid O'Meara Jan 2011

Design Of A Centralised Anaerobic Digestion Plant In Ireland., Diarmuid O'Meara

Theses

Climate change is brought about by greenhouse gases emitted to the earth’s atmosphere by fossil fuels. Renewable energy sources are seen as an alternative to fossil fuels. Examples of renewable energy sources are biofuels which are a method of reducing the emission of greenhouse gases. One form of biofuels is biogas that is produced during the anaerobic digestion process. In this thesis pig slurry is used to produce biogas.

In this project, the optimum design process for a centralised anaerobic digestion plant was established in the literature review, The optimum process for anaerobic digestion plant design in Ireland was investigated. …


Composition-Structure-Property Relationships For Experimental Composite Nerve Guidance Conduits, Xiaofang Zhang Jan 2011

Composition-Structure-Property Relationships For Experimental Composite Nerve Guidance Conduits, Xiaofang Zhang

Theses

Many Nerve Guidance Conduits (NGCs) have been approved by the Food and Drug Administration (FDA) as an alternative to nerve autografting for guiding peripheral nerve regeneration. However these materials offer little therapeutic potential for favourable axon growth environment, and difficulty in balancing the mechanical properties and the degradation rate of the implanted material is also a contemporary challenge. This project involved the design of experimental composite NGCs comprising glass particles and Pluronic FI27 in the copolymer (poly(lactic-co-glycolic acid)) and examined the composition-structure-property relationships for such materials. Three glasses (0.5Si-(x) Na-0.2Ca-0.13Zn-(0.17-x) Ce) (0.0.04 > x > 0.14) were produced. Glasses were characterised using …


Feasibility Report On Use Of Anchored Gravity Bases For Offshore Wind Turbines, Anthony Hayes Jan 2011

Feasibility Report On Use Of Anchored Gravity Bases For Offshore Wind Turbines, Anthony Hayes

Theses

In recent years, the demand for renewable energy in Europe has been rising substantially, as a result of statutory demands put in place by the European Union. It is expected that a relatively large proportion of future renewable electricity will be supplied by offshore wind farms. The offshore wind industry is currently attempting to design and evaluate cost effective foundation systems suitable for water depths greater than 30m. There is also a drive to reduce foundation costs for offshore wind turbines at present. This project is a preliminary feasibility report on an anchored gravity base foundation concept for deployment at …


Protection Of Embedded Systems For Applications Involving High Loading Rate Mechanical Forces, Amjad Alsakarneh Jan 2011

Protection Of Embedded Systems For Applications Involving High Loading Rate Mechanical Forces, Amjad Alsakarneh

Theses

This thesis describes the development of a methodology to optimise the dimensions and mechanical properties of force-absorbing layers surrounding miniaturised embedded electronic modules subject to high mechanical compressive/impact forces and vibration. While much has been published on the mechanical protection of electronic systems in larger scale applications, where traditional mechanical shock absorbers and springs can be used to protect the electronics, little has been published on the mechanical protection of miniature electronic modules embedded in smart structures and materials where traditional methods of mechanical protection are not feasible. The generalised system concept used in this thesis is of module encapsulation …


Scenario Generation And Climate Change Modelling Of Nitrous Oxide Emissions From Grasslands In Ireland, Mark Cochrane Jan 2011

Scenario Generation And Climate Change Modelling Of Nitrous Oxide Emissions From Grasslands In Ireland, Mark Cochrane

Theses

Described as a two-year study in relation to nitrous oxide emissions from agricultural grassland in the Republic of Ireland under a set or climate and environmental policy scenarios. Nitrous oxide is a greenhouse gas, with a global warning potential approximately three hundred times that or carbon dioxide. lt is required under the Kyoto Protocol that national inventories or all greenhouse gas emissions are established. The Intergovernmental Panel on Climate Change (IPCC) Tier approach is designed to establish current inventories of greenhouse gas emissions; however a scenario approach is also employed in order to estimate emissions in future years. Scenario sets …


The Optimum Energy Crop In Ireland For Biofuel, Eoin Deasy Jan 2011

The Optimum Energy Crop In Ireland For Biofuel, Eoin Deasy

Theses

The motivation for this research stems from the potential of biofuels to assist Ireland in meeting obligations outlined in the 'Renewable Energy Source Directive' (2009/28/EC) and to reduce dependency on fossil fuels. The purpose of this work is to establish the merits of biofuel production Ireland ,with a keen focus on the technical, economic and environmental aspects of each. The three biofuel options investigated are biodiesel, bioethanol and biomethane. Eight crop varieties were investigated, these include; wheat, oats, barley, OSR, maize silage, sugar beet, grass silage and potatoes. The approach taken within this thesis was to perform a life cycle …


Geotechnical, Environmental And Regulatory Aspects Of Brownfield Development, Martin Casey Jan 2011

Geotechnical, Environmental And Regulatory Aspects Of Brownfield Development, Martin Casey

Theses

Brownfield sites are a common feature of the urban landscape, have significant development potential and when remediated are the catalysts for urban regeneration. However, site specific information regarding geotechnical and environmental aspects of the site, including regulatory issues are needed in terms of bringing the land back into beneficial use. This research project discusses current Irish practice and regulation in respect of brownfield development. A comparison is made between Ireland, the United Kingdom, and the European Union in this regard. A review of all available literature indicates a number of shortcomings in respect of the geotechnical, environmental and regulatory aspects …


Arguing Security Of Generic Avionic Mission Control Computer System (Mcc) Using Assurance Cases, Bhanuchander Reddy Poreddy, Steven Corns Jan 2011

Arguing Security Of Generic Avionic Mission Control Computer System (Mcc) Using Assurance Cases, Bhanuchander Reddy Poreddy, Steven Corns

Engineering Management and Systems Engineering Faculty Research & Creative Works

An assurance case is a body of evidence organized into an argument demonstrating that some claim about a system holds, i.e., is assured. Assurance cases are used to comment about system safety, and it serves as a mean to show that the systems acceptably satisfy their safety properties. Assurance cases perform rigorous security analysis on safety-critical complex systems. in this paper, the analysis done is an approach to documenting an assurance case for system security, i.e., a security assurance case. the paper deals with the Assurance cases for Generic Avionic Mission Control Computer system, by constructing tangible claims and investigating …


Local Linear Regression For Soft-Sensor Design With Application To An Industrial Deethanizer, Zhanxing Zhu, Francesco Corona, Amaury Lendasse, Roberto Baratti, Jose A. Romagnoli Jan 2011

Local Linear Regression For Soft-Sensor Design With Application To An Industrial Deethanizer, Zhanxing Zhu, Francesco Corona, Amaury Lendasse, Roberto Baratti, Jose A. Romagnoli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Soft-Sensors for Estimating in Real-Time Important Quality Variables Are a Key Technology in Modern Process Industry. the Successful Development of a Soft-Sensor Whose Performance Does Not Deteriorate with Time and Changing Process Characteristics is Troublesome and Only Seldom Achieved in Real-World Setups. the Design of Soft-Sensors based on Local Regression Models is Becoming Popular. Simplicity of Calibration, Ability to Handle Nonlinearities And, Most Importantly, Reduced Maintenance Costs While Retaining the Requested Accuracy Are the Major Assets. in This Paper, We Introduce Several Approaches for Defining an Appropriate Locality Neighborhood and We Propose a Recursive Version of Local Linear Regression for …


Thermal-Aware Cell And Through-Silicon-Via Co-Placement For 3d Ics, Jason Cong, Guojie Luo, Yiyu Shi Jan 2011

Thermal-Aware Cell And Through-Silicon-Via Co-Placement For 3d Ics, Jason Cong, Guojie Luo, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Existing thermal-aware 3D placement methods assume that the temperature of 3D ICs can be optimized by properly distributing the power dissipations and ignoring the heat conductivity of though-silicon-vias (TSVs). However, our study indicates that this is not exactly correct. While considering the thermal effect of TSVs during placement appears to be quite complicated, we are able to prove that when the TSV area in each bin is proportional to the lumped power consumption in that bin, together with the bins in all the tiers directly above it, the peak temperature is minimized. based on this criterion, we implement a thermal-aware …


Virtual Prototype Modeling And Simulation Of Pipe Wagon Articulating System, Y. Li, Samuel Frimpong, W. Y. Liu Jan 2011

Virtual Prototype Modeling And Simulation Of Pipe Wagon Articulating System, Y. Li, Samuel Frimpong, W. Y. Liu

Mining Engineering Faculty Research & Creative Works

Virtual prototype of pipe wagon articulating (PWA) system has been developed and simulated based on the kinematics and dynamics of machinery and Automatic Dynamic Analysis of Mechanical Systems (ADAMS) software. It has been integrated with real-time three dimensional (3-D) system simulations for detailed and responsive interaction with dynamic virtual environments. By using this virtual model, the conceptual design examination and performance analysis of the PWA system have been realized dynamically in virtual laboratory. System dynamic force, displacement and tension of pipe have been measured through verifying this 3- D virtual prototype. By comparing the static tension and dynamic tension of …


The Bioactivity And Ion Release Of Titanium-Containing Glass Polyalkenoate Cements For Medical Applications, A. W. Wren, N. M. Cummins, F. R. Laffir, S. P. Hudson, Mark R. Towler Jan 2011

The Bioactivity And Ion Release Of Titanium-Containing Glass Polyalkenoate Cements For Medical Applications, A. W. Wren, N. M. Cummins, F. R. Laffir, S. P. Hudson, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The ion release profiles and bioactivity of a series of Ti containing glass polyalkenoate cements. Characterization revealed each material to be amorphous with a Tg in the region of 650-660°C. The network connectivity decreased (1.83-1.35) with the addition of TiO2 which was also evident with analysis by X-ray photoelectron spectroscopy. Ion release from cements were determined using atomic absorption spectroscopy for zinc (Zn2+), calcium (Ca2+), strontium (Sr2+), Silica (Si4+) and titanium (Ti4+). Ions such as Zn2+ (0.1-2.0 mg/l), Ca2+ (2.0-8.3 mg/l,) Sr2+ (0.1-3.9 mg/l), and Si4+ …


Survey On Cloud Forensics And Critical Criteria For Cloud Forensic Capability: A Preliminary Analysis, Keyun Ruan, Ibrahim Baggili, Joe Carthy, Tahar Kechadi Jan 2011

Survey On Cloud Forensics And Critical Criteria For Cloud Forensic Capability: A Preliminary Analysis, Keyun Ruan, Ibrahim Baggili, Joe Carthy, Tahar Kechadi

Electrical & Computer Engineering and Computer Science Faculty Publications

In this paper we present the current results and analysis of the survey “Cloud forensics and critical criteria for cloud forensic capability” carried out towards digital forensic experts and practitioners. This survey was created in order to gain a better understanding on some of the key questions of the new field - cloud forensics - before further research and development. We aim to understand concepts such as its definition, the most challenging issues, most valuable research directions, and the critical criteria for cloud forensic capability.


Cat Detect (Computer Activity Timeline Detection): A Tool For Detecting Inconsistency In Computer Activity Timelines, Andrew Marrington, Ibrahim Baggili, George Mohay, Andrew Clark Jan 2011

Cat Detect (Computer Activity Timeline Detection): A Tool For Detecting Inconsistency In Computer Activity Timelines, Andrew Marrington, Ibrahim Baggili, George Mohay, Andrew Clark

Electrical & Computer Engineering and Computer Science Faculty Publications

The construction of timelines of computer activity is a part of many digital investigations. These timelines of events are composed of traces of historical activity drawn from system logs and potentially from evidence of events found in the computer file system. A potential problem with the use of such information is that some of it may be inconsistent and contradictory thus compromising its value. This work introduces a software tool (CAT Detect) for the detection of inconsistency within timelines of computer activity. We examine the impact of deliberate tampering through experiments conducted with our prototype software tool. Based on the …


On The Advantages Of E100 Over Gasoline In Down-Sized, Turbo-Charged, Direct-Injected, Variable Valve Actuated, And Stoichiometric S.I. Engines, Alberto A. Boretti Jan 2011

On The Advantages Of E100 Over Gasoline In Down-Sized, Turbo-Charged, Direct-Injected, Variable Valve Actuated, And Stoichiometric S.I. Engines, Alberto A. Boretti

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Current flexi fuel gasoline and ethanol engines have efficiencies generally lower than dedicated gasoline engines. Considering ethanol has a few advantages with reference to gasoline, namely the higher-octane number and the larger heat of vaporization, the paper explores the potentials of dedicated pure ethanol engines using the most advanced techniques available for gasoline engines, specifically direct injection, turbo charging and variable valve actuation. Computations are performed with state-of-the-art, well validated, engine and vehicle performance simulations packages, generally accepted to produce accurate results targeting major trends in engine developments. the higher compression ratio and the higher boost permitted by ethanol allows …