Engineering Commons^™

Reduction Of Acoustic Feedback Oscillations By Use Of Spectrum Shifting, Youssef Abdelilah

Theses

The problem of whistling noise or self-oscillation in public address systems operating in closed halls or rooms can be very disturbing to the listeners. This noise is sustained when the positive acoustic feedback, of the public address-room system, meets the oscillation criteria. This feedback system results from the acoustic sound signal reflected off the room walls and any other obstacles in the room, originating from the public address speakers and then re-entering the microphone.

When all of the audio signal components entering the public address system are shifted by a frequency increment Δf of 6 Hz, an increase of 5 …

Evaluation Of Truck Restrictions Using Simulation, Shaikh Mohamed Arif

Theses

Traffic congestion is a major problem in many central business districts. Many strategies have been proposed and implemented to solve or alleviate this problem. One of the most common strategies is to impose travel restrictions on the movement of trucks, without reviewing the economic consequences of goods movement restrictions on shippers, customers and on the overall business activity of the area.

This research examines the effect of various truck restrictive policies on the cost of urban goods movement, using the central business district of Manhattan as a case study. Computer simulation techniques are used to evaluate several scenarios under different …

Behavior Of R/C Columns Under Nonproportional Variations In Axial And Lateral Loads, Kaniz Fatema Ahsan

Theses

The study on the behavior of reinforced concrete columns subjected to the motion of earthquake suggests that the structure may experience nonproportional variations in axial and lateral forces. In order to assess the capacity of a reinforced concrete structure under nonproportional loadings, an analytical model is developed using the fiber modeling technique.

The method is based on detailed analytical description of the geometry and material properties used in evaluating the behavior of the critical regions rather than a simplified and predefined set of hysteresis rules. The present study has two principal components of investigation. First, the analyses are done at …

Forward Kinematics Solution Of A Special Class Of General Stewart Platforms, Jian Li

Theses

A Stewart platform is a fully parallel, six-degree-of-freedom manipulator mechanism. A platform manipulator has a fixed platform acting as base, a mobile platform on which end-effector is mounted, and in-parallel kinematics chains (legs) between the two platforms. Although some direct position kinematics solutions for Stewart platforms of simplified geometry have been represented, to the best of our knowledge, no close-form direct kinematics solution for the general Stewart platform is available yet.

A common feature of six-degree-of-freedom Stewart platform of simplified geometry is the use of pairs of concentric ball joints. Due to inevitable manufacturing and assembly errors, practically there are …

Graphics Interfaced Computer Automated Process Planning, Ajit Nimbvikar

Theses

The work is based on the manufacturing of gears in a Job Shop type production plant. The topic is divided into three sections. 1. design, 2. graphics, and 3. process planning and analysis. A program is developed using Fortran for the iterative design procedure. With basic inputs, the program provides the design of gears with dimensions. During the procedure, the user has to intervene to specify some codes for the selection of materials and other parameters. Second section deals with the graphics utility. It provides a drawing of the gear with dimensions according to the input obtained from the design …

Development Of A Model For An Objective Minimum Resolvable Temperature Difference Characterization Of An Infrared Camera, Christine Issa Mourad

Theses

The parameter almost universally adopted by the infrared community for describing the overall performance of a thermal imaging camera is the minimum resolvable temperature difference. Unfortunately, this criterion is subjectively determined by a group of observers and as a consequence significantly varying results can be obtained at different times. This project describes work on an approach which ultimately aims to replace the observers by a computer-aided installation that simulates the human process by which the MRTD is estimated. The simulation is based on a direct measurement of signal to noise ratio in the image of the target and a determination …

Heat Resistance Measurements With The Portable Calorimeter Box, Philipp G. Mohr

Theses

The heat resistance of wall section materials has been investigated under laboratory conditions, but reliable measurements in-situ with non-steady weather conditions are not yet available. The portable calorimeter box is designed to make field measurements to test the thermal performance of building envelopes. The experimental setup and the equipment for thermal measurements are described, as well as the computer program for data reduction. The characteristics of the portable calorimeter box and the problems of non-controllable test conditions have been investigated.

Forty experiments were completed. Sixteen preliminary experiments investigated problems associated with insufficient setups; such as a short duration, only partly …

Torque And Current Response Due To Singularity Changes Of Induction Machine Slip, Jessie G. Orpilla

Theses

Recognizing that the prime purpose of the 3 phase induction motor is to deliver torque with minimum line current. This thesis studies the torque as well as the current response produced by the singularity changes in the induction machine slip. It is desirable that the torque to be maximized for a given value of line current at the corresponding load slip.

This thesis analyzes the torque and current response, when a slip at no-load is changed to a unit-step, Qu(t), a unit-impulse, Qδ(t), a pulse characterized by Q[u(t)-u(t-T)], a unit-ramp, Qt, and a sinusoidal, Qsint, slip. The responses are analyzed …

Translation Of Images On The Hypercube Using Leaf Codes, Bhavesh Patel

Theses

Image processing is used for manipulation of pictorial images. Image analysis applications are typically characterized by the need to process large quantities of image data. Some of the important transformations or operations which are car¬ried out by image processing systems are translation, scaling, superposition and rotation. Algorithms have been developed to carry out these transformations on image regions represented by quadtrees. Gargantini introduced an algorithm to translate an image region represented by a linear quadtree or leafcodes. A linear quadtree is a space efficient data structure used for storing digital images. Ziavras et.al. have proposed a modification of Gargantini's algorithm …

Development Of A Composite User Equilibrium And System Optimization Assignment Model, Kimberly M. Stump

Theses

The Urban Transportation Modeling System (UTMS) is a set of procedures used by transportation planners to predict the volume of traffic that will flow through a network, and how the traffic is routed. This paper will focus on the final component of UTMS, traffic assignment, which assigns the traffic flows to actual routes in the network.

In this paper, two composite models which model both User Equilibrium and System Optimal assignments are presented. The composite models are solved using the GAMS (General Algebraic Modeling System) software, a powerful mathematical programming tool. The first model was based on Beckman's Formulation, (Beckman, …

Fingerprint Pattern Recognition For Medical Uses, Feng You

Theses

The purpose of my research is to provide a method to automatically classify fingerprints into three subgroups: whorl, loop and arch, which can help medical scientists to study the relationship between fingerprint patterns and medical disorders. In the research, two different kinds of approaches were developed. The first one is performing pattern recognition in the frequency domain, which uses the feature of Fourier spectrum. That is, prominent peaks in the spectrum give the principal direction of fingerprint patterns. Using the above feature, we can obtain the principal direction of every subregion, after which the pattern of the whole image can …

A Study Of Pulsation Of Chest Wall Using Microwave Interferometer, Paul Zeno

Theses

The microwave interferometer is utilized to pick up vibrations of the anterior chest wall produced by the cardiac activity. The objective of this project is to find the causes of different peaks in the output of the microwave interferometer. The output of the microwave interferometer is recorded simultaneously with EKG and jugular pressure pulses. Eighteen subjects had their mechanical vibrations of the chest wall, EKG and jugular pressure pulses recorded. The processed interferometer data, when compared with EKG and jugular pressure pulses appear to have a close relation to the mechanical events in the cardiac cycle. Four peaks in the …

The Thermal Model Of The Rat Under Hemorrhagic Shock Hypothermia With Microwave Intervention, Liu Zhe

Theses

A whole body thermal model simulating heat distribution and temperature regulation in rats during hemorrhagic shock and during post-shock microwave core rewarming period was developed. An electrical circuit was used to simulate the thermal system and a software named PSpice? was used to analyze the circuit. The temperature regulation as the result of the simulation is demonstrated to match the measured temperature histories of rats in hemorrhagic shock and the microwave rewarming experiment.

The blood pressure drop and cardiac output decrease were considered in the simulation and the so called "set point temperature" was investigated in the model. Linear decrease …

Computer Aided Finite Element Stress Analysis Of A Three Dimension Mandibular Bone Model Using I-Deas Software, Yixiong Xu

Theses

A three dimensional model of half of the mandibular bone, with 487 tetrahedra elements and 1,047 nodes, is established and analyzed by means of I-DEAS software. The masseter muscle is assumed to be 15° deviation from y-axis, and the Umetani boundary conditions are allowed to be varied. A 337 lb force was applied along the midline of the mandible to simulate a trauma force caused by the auto accident. The maximum principal stress is 18,400 psi and the minimum principal stress is -1,340 psi. Depending on the experimental results of dispalcement and maximum principal stress, the conclusions are drawn: 1) …

Cause And Effect Diagrams For Process Analysis And Control, Philip Thomas

Theses

Cause and effect diagrams can be used as an effective tool for identifying the possible causes of a quality problem. Using this diagram one can go deep into the causes of the problem and take proper remedial action. Several graphical techniques like matrix diagrams, systematic diagrams, etc., can be combined with this tool to better represent the cause effect relationships. While a quantitative approach of this technique is feasible but limited, there are useful applications based on qualitative approach to this technique. The objective of this thesis is to propose a quantitative approach to the cause and effect diagrams especially …

Design Of Holographic Optical Interconnections, Su-Chiou Tsay

Theses

Optics have many advantages over electronics in interconnecting systems together, particularly in terms of higher transmission speed and better immunity to noise. Optical interconnections may be used at all levels of computing: for local area networks, between processors or memory elements, and between boards.

In this thesis, we attempted to generate a new type of computer hologram for optical interconnection purposes. The holographic method is very promising whenever integrated optical interconnections are considered. In this research we have tried two designs: the shortest path grating design which can maximize the global output energy and the single input maximum output grating …

Design For Productivity Using Gd&T, Srihari G. Acharya

Theses

No abstract provided.

Mineralization Of 2-Chlorophenol Using A Hollow Fiber Ultrafiltration System In Combination With A Reactor Containing An Immobilized White Rot Fungus, Sheau-Ming Tung

Theses

Phanerochaete chrysosporium, a white rot fungus was immobilized on a packed-bed reactor, and was used to mineralize an aqueous stream contaminated with 50 ppm of 2-chlorophenol. Hollow fiber ultrafiltration membranes (for 5,000 daltons and 10,000 daltons molecular weight cut-oft) were utilized to retain the extracellular enzyme resulting from the immobilized fungus in a recirculation loop outside of the reactor.

It was found here that the concentration of proteins (roughly proportional to the extracellular enzyme releasd by the fungus) does not correlate with the rate of degradation of 2-chlorophenol in the system. The protein was concentrated 1.5 fold in the recycle …

Adaptive Map Configuration And Dynamic Routing To Optimize The Performance Of A Satellite Communication Network, Santhalingam Balasekar

Theses

Availability of alternate routes are shown to enhance the performance of non-hierarchical circuit switched networks at moderate load conditions on which the networks typically operate. But alternate routes introduce instability at heavy and overloaded conditions and at these load conditions the network performance is found to deteriorate. To alleviate this problem, one of the control mechanism used is to reserve a fraction of the capacity of each link for direct routed calls. In this work, the feasibility of changing the facilities of a satellite network is taken advantage in optimizing the performance of such a network. A mesh connected, circuit …

The Acoustic Properties Of Human Femoral Bone, Mark Lacianca

Theses

Over the last decade, interest has grown in the use of the scanning acoustic microscope (SAM), with a single lens being used for both transmitting and receiving the acoustic signal. A major objective of this thesis was to determine if the transmission and ultrasonic techniques yield similar "quantitative" results, when measuring the elastic constants of human femoral bone. The transmission technique has been used since 1970 to yield values for the elastic properties of calcified tissue. Previously the SAM has been used as a qualitative tool, where an acoustic impedance map is produced. This map can show areas of bone …

Shop Floor Planning And Control In Integrated Manufacturing Systems, Tahir Mahmood

Theses

The implementation of a shop floor planning and control system is a prerequisite in establishing an effective computer integrated manufacturing system. A shop floor control system integrates management production goals with the capabilities and limitations of the manufacturing plant. Shop floor planning begins with a long term rough cut capacity plan and evolves into near term, capacity requirements and input/output plans. Shop floor control provides a status of in-process operations and a measure of the plants success in executing the plan. Effective use of technology on shop floor increases the efficiency of the manufacturing plant. Simulation is an important tools …

An Information Theoretic Approach To Dsn Evaluation, Vivek Mehrotra

Theses

Evaluation of Distributed Sensor Networks (DSN's) for optimal detection using Bayesian cost formulation methods has been the objective of several studies. There have been a few studies on DSN evaluation using an information theoretic approach, wherein an assymetric channel models a detector. We look at the multi-sensor system at the receiver as a black-box and model it as an assymetric channel whose cross over probabilities depend on the probabilties of detection and of false alarm. These probabilities in turn depend on the thresholds of the local detectors and on the fusion rule used. We consider the case wherein the receiver …

Design For Manufacturability And Assembly, Srinivas Mullapudi

Theses

This report presents a study of the various concepts of design for manufacturability and assembly with some case studies, and examples.

The goal of DFM is reduction of parts and simplifying assembly process. A simple faucet has been studied and attempts have been made at re-designing the same using the techniques of design for manufaturability as postulated by Boothroyd, Dewhurst and Henry Stoll.

Development Of The Interface Between Cad And Waterjet Nc Systems, Sivayasivan Sambandan

Theses

There has been a continuous need in the present to develop softwares that provide interface between cutting machines and computer control. There involves a number of complex stages from the birth of an algorithm, to develop such software, till the end where it successfully gets tested and implemented. Cutting Path Simulation (CPS) is a partially developed software designed to model 2-d and 3-d objects and down load them to water jet cutting machine. Additional menus were created in the software to perform specific functions. Bugs that existed in the previously done work were removed. Investigation was conducted on the feasibility …

Planning Of Optimal Transit System Design, Yongning Liu

Theses

This study presents a methodological approach for finding an optimal design of bus transit service in an urban transportation corridor with elastic demand and under various objective functions. Service design decision variables to be optimized include the route length, route density, headway, number of stops and stop spacing pattern. The objective functions that optimize the transit system design include: minimizing operator cost, maximizing profit, minimizing sum of operator and user costs and maximizing the users' net benefits.

The analysis uses an elastic demand function wherein the number of trips are sensitive to the quality of service provided and price charged …

The Collapse Of The Cypress Viaduct During The Loma Prieta Earthquake Of October 17, 1989, Mohamed M. Eid

Theses

The Loma Prieta earthquake of October 17, 1989 in California was one of the most disastrous earthquakes in U.S history. It caused damage to commercial, residential, and industrial structures, transportation and utilities.

This study includes investigations about the Cypress Viaduct collapse re?ported by:

1. California Governor's Board of Inquiry [4].
2. National Institute of Standards and Technology (NEL) W.
3. 3The Author.

Investigators in the first report concluded that the collapse was due to horizontal ground motion. In the second one, it was due to the vertical ground motion.

In the author's investigation, a detailed static and dynamic analyses are performed to determine …

A Study Of Annular Slurry Jet For Abrasive Waterjet Cutting, Thomas Kuriakose

Theses

The objective of this project is to study the performance of an annualr slurry jet nozzle for abrasive waterjet cutting. This nozzle has been invented by Avraham. Harnoy, Department of Mechanical Engineering, NJIT and presented to the patent committee of NJIT in May 1990. This study includes design and development of prototyes and testing of their performance. Moreover, it includes initial theoretical study of the flow behavior.

The idea is based on the merging of a high velocity pure waterjet with an annular jet of a slurry of water and abrasives at low velocity. The two jets merge outside the …

Removal Of Volatile Organic Compounds (Voc's) Acetone And Ethyl Alcohol Emitted In The Manufacture Of A Multi-Base Propellant, Yih-Leu Liu

Theses

The Production Base Modernization Activity located at Picatinny Arsenal, initiated this study for the removal of the low concentrations of VOC's, acetone and ethyl alcohol emitted from the mixer operation and the forced air dry unit in the manufacture of a multi -base propellant. Air pollution requirements necessitate 85 % removal of the VOC's prior to discharge of the vent gases into the atmosphere. Because of the availability of sulfuric acid, it is proposed to use 70 percent or stronger acid as the absorbing agent in a recirculating acid absorption tower.

Vapor - Liquid Equilibrium ( VLE ) data were …

Cost Deployment Based On Quality Function Deployment, John Goceljak

Theses

A methodology for Cost Deployment based on Quality Function Deployment (QFD) architecture is developed and explained. Following a comprehensive review of Quality Function Deployment terminology and composition, a house-of-quality is developed, and matrix correlation methodologies are discussed. Current applications are presented to illustrate the scope and adaptability of this quality assurance tool. In addition, an exercise in product design and review is conducted to illustrate a unique approach to cost deployment. Quality Function Deployment issues, including software, consulting, and preferred practices are also presented.

Quantitative Assessment Of Myocardial Oxygen Supply And Demand Using A Dynamic Model Of The Cardiovascular System, Badrinath R. Puranic

Theses

A quantitative understanding of the changes in coronary, pulmonary and systemic hemodynamic variables and their effect on myocardial supply and demand is important to the better management of anesthetic care of patients with impaired cardiac function. Animal studies have identified those hemodynamic factors that play an important role in determining the balance between oxygen supply and demand for the myocardium. These include myocardial contractility, left ventricular end-diastolic volume, systemic arterial pressure, systemic vascular resistance, and heart rate. The interactions of these factors are complex and their combined effects on myocardial oxygen supply and demand are difficult to predict a priori. …