Engineering Commons^™

Parallel Interference Cancellation Multiuser Detectors For Ds-Cdma Communication Systems, Feng Liu

Electrical Engineering Dissertations - Archive

A non-linear sub-optimal multiuser detector in the form of parallel interference cancellation (PIC) has been studied. The main objective of this thesis is to develop an analytical model for PIC performance analysis and propose new near-optimum approach. Since the exact performance analysis of PIC is difficult to derive due to its nonlinear decision function, previous work tends to adopt computer simulation method or evaluate through Gaussian approximation (GA) method. For PIC detector, the GA method may not apply since there may exist a dominate interference signal. In addition, the central limit theorem is not applicable to model the residual MAI …

Multi-Area Unit Commitment And Economic Dispatch With Market Operation Components, Chitra Yingvivatanapong

Electrical Engineering Dissertations - Archive

Unit commitment and economic dispatch, when combined together, is a useful tool to find the most economical generation schedule with which demand and spinning reserve requirement are supplied and all generating unit constraints, such as unit ramp rates, unit minimum and maximum generation capabilities, and unit minimum up-time and down-time, are satisfied over a time horizon. For systems consisting of multiple areas, area import/export capabilities and tie line capacity constraints also need to be taken into account. Enhanced Lagrangian relaxation, unit decommitment and lambda-iteration methods are applied in this dissertation to determine the optimal unit commitment and economic dispatch schedule …

Numerical Study On Capillarity- Dominant Free Surface And Interfacial Flows, Zhaoyuan Wang

Mechanical and Aerospace Engineering Dissertations - Archive

The continuum surface force (CSF) method has been extensively employed in the volume-of-fluid (VOF), level set (LS) and front tracking methods to model surface tension forces. Its ability is limited for the surface tension dominant free surface and interfacial flows due to the existence of spurious currents. These currents may lead to disastrous interface instabilities and failure of grid convergence, which are present in all the previous versions of the CSF algorithm. In this study, a coupled level set and volume-of-fluid method (CLSVOF) is employed for interface tracking, which offers more accurate computations of the curvature and the normal vector …

Cee3030 - Uncertainty In Engineering Analysis, Spring 2006, Gilberto E. Urroz

Civil and Environmental Engineering - OCW

This course on uncertainty in engineering analysis can also be referred to as probability and statistics for engineers. In particular, we will deal with the applications of probability and statistics to problems related to civil and environmental engineering. Note: Technical Requirements, Maple 10 by Maplesoft

Cee3500 - Fluid Mechanics, Spring 2006, Gilberto E. Urroz

Civil and Environmental Engineering - OCW

Explores fluid properties, hydrostatics, fluid dynamics, similitude, energy and momentum principles, closed conduit flow, open channel flow, and flow measurement. Includes laboratory exercises in flow measurement, open channel flow, pipe friction, physical modeling, and data collection.

Cee6510 - Numerical Methods In Civil Engineering, Spring 2006, Gilberto E. Urroz

Civil and Environmental Engineering - OCW

Engineering applications of approximation and interpolation, solution methods for ordinary differential equations, numerical solution of partial differential equations, nonparametric and parametric probability and regression estimation, and Monte Carlo and uncertainty analysis.

Technical Requirements: Maple 10 by Maplesoft,

Matlab

Implantable Drug Delivery System With In-Plane Micropump, Amit A. Mhatre

Bioengineering Theses - Archive

A MEMS based Implantable Drug Delivery System (IDDS) is discussed. The heart of the system is an in-plane MEMS micropump enables us to make a compact, inexpensive system. A conceptual IDDS design is proposed. This design consists of an implantable unit which houses the micropump, electronic and power circuitry. This implantable unit is connected to a subcutaneous port via a silicone catheter. The subcutaneous port acts as a refillable reservoir. This leads to a reduction in unit volume and makes the system customizable. The IDDS pumps drug into surrounding tissue with the help of a MEMS-based micropump. The force generated …

Treating Soil Pentachlorophenol (Pcp) At Optimal Conditions Using Heme And Peroxide, Shyi Tien Chen, David King Stevens, Guyoung Kang, M. J. Hsieh

Civil and Environmental Engineering Faculty Publications

The environmental impact of pentachlorophenol (PCP) has been the subject of extensive research in recent years. Investigations of PCP degradation using both biotic and abiotic methods are extensively reported in literature. Based on some preliminary tests (not shown), an abiotic method was found for oxidative PCP degradation in soil under unsaturated conditions and a neutral pH. Reagents used were heme (a catalyst) and peroxide (an oxidant). From two screening tests (not shown), the heme and peroxide were identified as the most important factors on PCP degradation in highly PCP-contaminated soil. The objective of this study was to determine the optimum …

Impacts Of The 2004 Tsunami On Groundwater In Sri Lanka, T. Illangasekare, S. W. Tyler, T. P. Clement, K. G. Villholth, A. P.G.R.L. Perera, J. Obeysekera, A. Gunatilaka, C. R. Panabokke, D. W. Hyndman, K. J. Cunningham, W-G. Yeh, Jagath J. Kaluarachchi, M-Rien Van Genuchten, K. Jensen

Civil and Environmental Engineering Faculty Publications

The 26 December 2004 tsunami caused widespread destruction and contamination of coastal aquifers across southern Asia. Seawater filled domestic open dug wells and also entered the aquifers via direct infiltration during the first flooding waves and later as ponded seawater infiltrated through the permeable sands that are typical of coastal aquifers. In Sri Lanka alone, it is estimated that over 40,000 drinking water wells were either destroyed or contaminated. From February through September 2005, a team of United States, Sri Lankan, and Danish water resource scientists and engineers surveyed the coastal groundwater resources of Sri Lanka to develop an understanding …

Active Flow Control Of Low Pressure Turbine Blade Separation Using Plasma Actuators, Karthik Ramakumar

University of Kentucky Master's Theses

The current study examines plasma actuators as flow control devices. The actuators are placed on a turbine blade profile in a 2D turbine cascade for separation flow control. The configuration involves copper strips separated by a layer of dielectric material, across which an AC electric potential in the range of 5 kHz and 5 kV is applied. The efficiency of the actuator is monitored by measuring power input and flow control effectiveness. Preliminary observations are performed for a quiescent case on a flat plate profile to analyze the average and instantaneous velocities generated by the actuator for varied input parameters, …

Numerical Study Of Chemically Reacting Viscous Flow Relevant To Pulsed Detonation Engines, Tae-Hyeong Yi

Mechanical and Aerospace Engineering Dissertations - Archive

A computational fluid dynamics code for two-dimensional, multi-species, laminar Navier-Stokes equations is developed to simulate a recently proposed engine concept for a pulsed detonation based propulsion system and to investigate the feasibility of the engine of the concept.The governing equations that include transport phenomena such as viscosity, thermal conduction and diffusion are coupled with chemical reactions. The gas is assumed to be thermally perfect and in chemically non-equilibrium. The stiffness due to coupling the fluid dynamics and the chemical kinetics is properly taken care of by using a time-operator splitting method and a variable coefficient ordinary differential equation solver. A …

Modular Multi-Scale Assembly System For Mems Packaging, Rakesh Murthy

Mechanical and Aerospace Engineering Theses - Archive

A multi-scale robotic assembly problem is approached here with focus on mechanical design for precision positioning at the microscale. The assembly system is characterized in terms of accuracy/repeatability and calibration via experiments. The MEMS packaging requirements are studied from an assembly point of view. The tolerance budget of the assembly ranges from 4 microns to 300 microns. The system components include robots, microstages, end-effectors and fixtures that accomplish the assembly tasks. Task assignment amongst this hardware has been accomplished based on precision and dexterity availability. Various end-effectors and fixtures have been designed for use with off-the-shelf hardware (robots and microstages) …

Interactions Between Antiwear Agent And Novel Additive In Engine Oils, Kajal Parekh

Material Science and Engineering Theses - Archive

Research has shown that side/end products of phosphorus and sulfur compounds in engine oils reduce effective life of exhaust catalysts of automobiles resulting in harmful emissions. Thus environmental regulations have been imposed on phosphorus levels in engine oils. The main source of phosphorus in today's oils is the indispensable antiwear agent Zinc Dialkyl Dithiophosphate (ZDDP). To find cost-effective non-phosphorus substitute has not proven fruitful. A unique way of reducing phosphorus or ZDDP level while maintaining good antiwear performance has been achieved by introduction of a novel additive FeF3 along with ZDDP. It appears that the interactions between FeF3 and ZDDP …

Design And Analysis Of Multi-Functional Laparoscopic Tool, Vadakkapattu Candadai Venkat Raghavan

Mechanical and Aerospace Engineering Theses - Archive

Laparoscopic tools have been developed over many years, but there is a need for a laparoscopic tool that can be used for multiple purposes without the need to be removed and reinserted in the body. This thesis discusses the design of such a multi-functional laparoscopic tool with the ability to independently actuate grasping and shearing mechanisms, and is modular enough to be easily adapted to robot assisted surgical techniques. The envisioned tool can be divided into three main sections - the surgeon interface, the transmission mechanism, and the end effector. The surgeon interface mainly consists of a handle and two …

Parametric Cycle Analysis For Pulse Detonation Engines, Haider Hekiri

Mechanical and Aerospace Engineering Theses - Archive

The performance of an ejector-driven pulse detonation engine (PDE) with an afterburner is analytically estimated. In the analysis, the PDE was modeled as a straight tube, closed at the front end and open at the other. A detonation wave starts to travel after it is ignited at the closed end, causing a Chapman-Jouguet detonation wave followed by a Taylor rarefaction to travel to the open end. At that point, rarefaction waves are reflected back to the closed end. The result is a high thrust due to both the primary and secondary flows of the ejector-driven PDE. A theoretical analysis is …

Airy Stress Function For Two Dimensional Inclusion Problems, Dharshini Rao Kavati

Mechanical and Aerospace Engineering Theses - Archive

This thesis addresses a problem of finding the elastic fields in a two-dimensional body containing an inhomogeneous inclusion using the Airy stress function which is determined so that the prescribed boundary condition at a far field and the continuity condition of the traction force and the displacement field at the interface are satisfied exactly. All the derivations and solving simultaneous equations are carried out using symbolic software.

Arc-Heated Gas Flow Experiments For Hypersonic Propulsion Applications, Christopher Matthew Roseberry

Mechanical and Aerospace Engineering Dissertations - Archive

Although hydrogen is an attractive fuel for a hypersonic air-breathing vehicle in terms of reaction rate, flame temperature, and energy content per unit mass, the substantial tank volume required to store hydrogen imposes a drag penalty to performance that tends to offset these advantages. An alternative approach is to carry a hydrocarbon fuel and convert it on-board into a hydrogen-rich gas mixture to be injected into the engine combustors. To investigate this approach, the UTA Arc-Heated Wind Tunnel facility was modified to run on methane rather than the normally used nitrogen. Previously, this facility was extensively developed for the purpose …

Reliability Of Lead-Free Solder Under Cyclic Bending, Fahad Zahedi

Mechanical and Aerospace Engineering Theses - Archive

To characterize particular compositions of lead free solder, four point cyclic bending test was conducted to study the affects of accelerated stress testing on the package to board interconnects. Nine CTBGA packages with 0.5 mm ball pitch and 12 x 12 mm package size were reflowed on 8 layered PWB's using solder balls with lead free composition alloys and different PWB copper pad finishes. The boards were subjected to test conditions based on proposed standards by JEDEC. Strain gages were mounted at different locations on the test boards as well as on bare boards in order to observe the difference …

Experimental Characterization Of Femtosecond Laser Micromachining For Silicon Mold Fabrication And Hot Embossing For Polymer Microreplication, Sunil Ranganath Belligundu

Mechanical and Aerospace Engineering Dissertations - Archive

Hot embossing is a fabrication technique employed for replicating microfeatures on a polymer surface that was primarily developed to fabricate MEMS devices for microfluidic applications. This manuscript deals with characterization of the femtosecond laser micromachining (FLM) and hot embossing (HEMM) processes for master mold fabrication on silicon and polymer replication respectively. Given the required size of the features to be fabricated or replicated, process parameters for FLM can be determined using the derived empirical equations, process parameters for the HEMM process can be established using the characteristic plots. A novel two-stage embossing process is developed and introduced that employs polymer …

Determination Of Safe Buffer Width Of Roadway To Protect Human Health Form Harmful Nox Exposure, Hetal H. Bhatt

Civil Engineering Theses - Archive

According to the 2004 EPA Trends Report, US on-road transportation sources emit 36% of nitrogen oxides (NOx), 63% of carbon monoxide (CO), and 29% of volatile organic compounds (VOCs). This research determines a safe roadway buffer width to protect human health from air pollutant (NOx) exposure. The method was used to determine a buffer width for NOx along Great Southwest Parkway in Grand Prairie, Texas. NOx health effects include eye, nose, throat, and lung irritation; cough; shortness of breath; tiredness and nausea. In the Dallas Fort Worth region, where Grand Prairie is located, on-road vehicles contribute over 50 % of …

Discharge Headway At Signalized Intersections In Monterrey, Nuevo Leon, Mexico, Luis F. Chapa

Civil Engineering Dissertations - Archive

Driver behavior has been the subject of study for almost 100 years. As a result, driver characteristics have been determined and used in the design of highway elements, both for interrupted and for free flow facilities. Signalized intersections represent the most typical interrupted flow facility, with driver reaction time and aggressiveness playing a key role in signal timing design and also in the assessing of intersection performance. These driver characteristics were first determined in the United States in the late 1940's, identifying an average headway (in seconds) between consecutive vehicles as they react to light change from red to green …

Investigation Of Breast Tumor Hemodynamics By Near Infrared Spectroscopy: Applications To Cancer Therapy Monitoring, Jae Gwan Kim

Bioengineering Dissertations - Archive

Hyperoxic gas interventions using carbogen (95% O2 and 5% CO2) or oxygen has been tried to increase the tumor oxygenation since it will enhance the therapeutic effects on the tumors. Others in the laboratory had previously applied near infrared spectroscopy (NIRS) to monitor the changes in tumor blood oxygenation during hyperoxic gas intervention and found that oxyhemoglobin concentration changes (D[HbO2]) during gas intervention can be fitted by a two-exponential equation containing two time constants. Based on the model, they formed a hypothesis that changes in oxygenated hemoglobin concentration result from well perfused and poorly perfused regions of an animal tumor …

Adaptive Sampling With Mobile Wsn, Koushil Sreenath

Electrical Engineering Theses - Archive

The spatiotemporally varying network topology of mobile sensor networks makes it very suitable for applications such as reconstruction of environmental fields through sampling at locations that maximally reduce the largest uncertainty in the field estimate. Mobile sensor networks comprise of multiple heterogeneous resources and a deadlock-free resource scheduling in the presence of shared and routing resources becomes necessary to schedule the most efficient (cost / energy / time) resource for a task. Location information is imperative in sensor networks for most applications for localized sensing where localizing the network adaptively with no additional hardware is important. Adaptive sampling approaches for …

Data-Logging & Supervisory Control In Wireless Sensor Networks, Choudhury Aditya Narayan Das

Electrical Engineering Theses - Archive

This thesis mainly emphasizes on the inclusion and implementation of the Supervisory control unit in the wireless sensor networks with a brief overlook on the cross-bow sensors and mobile sentry robots. The aim of this research has been to design an application module which would be able to manipulate the data effectively and support the Discrete Event Controller in generating the rule-based tasks by solving major issues like data-logging, alarm and event reporting and security concerns. The PC-based data logging systems provide the most flexibility, customization, and integration to the Wireless Sensor Network research project. This work has been supported …

Efficient Transcoding Of An Mpeg-2 Bit Stream To An H.264 Bit Stream, Rochelle B. Pereira

Electrical Engineering Theses - Archive

Low complexity fast transcoding of an MPEG-2 elementary stream to an H.264 elementary stream. Objective: MPEG-2 has been a widely accepted video coding standard for various applications ranging from DVD to digital TV broadcast. The new H.264 AVC standard has an even broader perspective to support high and low bit rate multimedia applications on existing and future networks. The advantage in terms of better quality at a lower bit rate is why H.264 is fast replacing MPEG-2. However, the user end hardware had previously been adapted for MPEG-2 streams. This gives rise to a need for portability between MPEG-2 and …

Analysis And Characterization Of Thermal Effects In Analog Circuits, Abhijit Avinash Chaugule

Electrical Engineering Theses - Archive

Dielectrically Isolated Bipolar Junction Transistors (DIBJTs) are used in industry for high speed and high power applications. These devices suffer from thermal heating and are subjected to change in their characteristics. This thesis explores the thermal effects involving the self heating and inter-device heating (thermal coupling) at the device as well as at the circuit level. Systematic analysis of individual device heating characteristics in a particular Current feedback operational amplifier (CFOA) design is carried out, using the VBIC (Vertical Bipolar Inter-company) model in the the Cadence SpectreS simulator. A diagnostic and design procedure is established for circuit designers to determine …

High Resolution Optical Coherence Tomography (Oct) System For Integration With A Multimodal Optical Imaging Workstation, Kapil Bharati Langer

Bioengineering Theses - Archive

Development and construction of a high resolution Optical Coherence Tomography (OCT) system is described. OCT is one of the modalities in an integrated multimode optical imaging workstation built around an inverted Differential Interference Contrast (DIC) microscope in our laboratory, to image cells and tissue samples. The design and construction of the OCT sample path is dictated by its integration to the optical imaging workstation. The OCT system is controlled via a DAC card, interfaced using LabVIEW to the computer. The image of the sample under observation is constructed from the raster scan data acquired by the DAQ. Ti-Sapphire broadband laser …

Failure Analysis Of Composite Laminates With A Hole By Using Finite Element Method, Moumita Roy

Mechanical and Aerospace Engineering Theses - Archive

Predicting the strength of a given laminate has been extensively studied. There have been several fracture models proposed but still the immense tests of composite laminates are still needed. Different material systems or lay-ups exhibit different failure modes and failure mechanisms. This thesis focuses in investigation of the failure mechanism of the [±?/02]s and [02/±?]s laminates with a hole. ANSYS finite element models with and without a crack in vicinity of hole were developed to investigate the effect of the stress distribution due to the presence of the angle ply crack. The stress concentrations were obtained. It is found that …

Structural Optimization Using Ansys And Regulated Multiquadric Response Surface Model, Ajaykumar Menon

Mechanical and Aerospace Engineering Theses - Archive

The high computational expense of large non-linear and complex finite element analysis limits or often prohibits the use of conventional codes in engineering design and multidisciplinary optimization. Consequently alternate methods such as Design of experiments (DOE) and Response surface approximation are commonly used to minimize the computational cost of running such analysis and simulation. The basic approach of such methods is to construct a simplified mathematical approximation of the computationally expensive simulation and analysis code, which is then used in place of the original code to facilitate multidisciplinary optimization, design space exploration, reliability analysis etc. When such codes along with …

Comparison Of Clinoptilolite With Gravel In A Recirculating Course Media Biofilter Treating Simulated Septic Tank Effluent, Adnan Sadikot

Civil Engineering Theses - Archive

The main objective of the pilot scale study was to compare the performance of recirulating clinoptilolite biofilter with course gravel biofilter used to treat simulated septic tank effluent by simultaneous nitrification and denitrification. For better comparison of performance of total inorganic nitrogen removal and COD removal both the biofilter were chosen of identical size and identical operating conditions were maintained in the laboratory setup. Both the biofilters were operated at recycle ratio of 6 and surface hydraulic loading rate of 7.5 gal/ft2/day without recycle and 52.5 gal/ft2/day with recycle through out the duration of the duration of the research. Results …