Digital Commons Network^™

A Survey Of Manufacturing Practices In Southeast Asia, Fe Irma A. Ramirez

Theses

This paper presents a study of the current manufacturing practices in Southeast Asia particularly Indonesia, Malaysia and the Philippines. This region is regarded as the next region to watch in terms of economic performance and potential. A mail survey of manufacturing companies in these countries was performed in order to get the data. A six-page questionnaire was sent and covered the following areas: company profile, production control and management, quality management and automation and computerization. Majority of the respondents were medium- and large scale companies and carried a wide array of products. Most of the firms were labor intensive rather …

Translation Of Semantic Aspects Of Oodini Graphical Representation To Onto Oodb Data Definition Language, Xiaoyong Wang

Theses

In this thesis we present a system to translate the semantic elements in the graphical schema language of OODINI from API of OODAL to the Type definition of ONTOS DB. To translate semantic constraints of the graphical language, we patch more information to existent class data structure in API of OODAL. After a brief review of OODINI, ONTOS DB and the existent translator without the ability to translate semantic constraints, we describe in detail the methods to translate the essential relationship. dependent relationship, multi-valued essential relationship and multi-valued dependent relationship. We employ an Inverse Reference to a "Set of" Type …

Oxidation Of Cyclohexene With Aqueous Potassium Peroxymonosulfate At Ph < 1.7, Wen-Qing Sun

Theses

Glycols are often used as starting materials for pharmaceuticals. They are currently manufactured by reacting alkenes with organic peroxy acids in organic solutions that contain chlorinated solvents. The aim of this research is to find ways to avoid the use of hazardous organic solvents in the manufacture of pharmaceuticals in order to prevent pollution. Our approach is to find alternative synthetic methods using water as solvent.

Based on literature information, it was decided to determine if the aqueous potassium peroxymonosulfate oxidation of water-immiscible cyclohexene at room temperature can be scaled up to become a new method to manufacture glycols. Acidic …

Catalytic Oxidation Of Chlorinated Hydrocarbons Over Powdered Transition Metal Oxide, Sanmei Xu

Theses

This study addresses the ability of powdered transition metal oxides such as manganese oxide, iron oxide and copper oxide to catalytically oxidize low concentrations of chlorinated hydrocarbons with air. The catalytic oxidation of trichloroethylene and dichloromethane in a tubular reactor system was evaluated experimentally as a function of temperature and space velocity. Gas chromatography with electron capture detector and flame ionization detector was used for quantitative analysis of feed and product streams. Gas chromatography/mass spectrometry and gas chromatography/Fourier transform infrared spectroscopy were used to identify all oxidation products. The results indicate that over 99% conversion of trichloroethylene is achieved at …

A Thermoelastic Model Applied To Stress Control In Laser Heating Of Ceramics, Jeff Alexander Wagner

Theses

Localized laser heating is widely used in materials processing. In extending these techniques to materials with relatively low thermal conductivities and ductilities such as ceramics and glasses, existing methods must be modified to control the high thermal stresses which are associated with the localized heating of these materials. Thermal profiles must be designed to minimize damage to regions adjacent to the processed area. To achieve this with single beam sources the power and radius can be varied in time, or the beam can be moved across the surface in a programmed pattern to achieve the desired thermal profile.

In this …

Introduction Of An Information Feedback Loop To Enhance The Urban Transportation Modeling System, Kyle B. Winslow

Theses

The Urban Transportation Modeling System (UTMS) is a methodology used to estimate urban travel demand. This demand is measured as the volume of traffic that flows through a system of streets and highways. Through the use of traffic assignment software, parts of UTMS have become automated. One of the newest automated processes is the extraction of a subarea from a larger model. This extraction process is important to the local planner because it maintains a linkage from the regional model to the local model and it allows the user to extract an already distributed trip table rather than building one …

Methodology For Modeling High Performance Distributed And Parallel Systems, Rakesh Kushwaha

Dissertations

Performance modeling of distributed and parallel systems is of considerable importance to the high performance computing community. To achieve high performance, proper task or process assignment and data or file allocation among processing sites is essential. This dissertation describes an elegant approach to model distributed and parallel systems, which combines the optimal static solutions for data allocation with dynamic policies for task assignment. A performance-efficient system model is developed using analytical tools and techniques.

The system model is accomplished in three steps. First, the basic client-server model which allows only data transfer is evaluated. A prediction and evaluation method is …

Engineering Design Of An Anaerobic-Aerobic System To Treat Chlorophenols, Chih-Ju Jou

Dissertations

The present work was aimed at determining the effect of the main operating parameters on the performance of an anaerobic-aerobic reactor system to degrade toxic chlorinated compounds. In previous work conducted in the Biological Treatment Lab at NJIT it was shown that this system is capable of achieving the complete degradation of chlorophenols. In that system, reductive dehalogenation took place in the first anaerobic reactor, which was followed by a second aerobic reactor in which the degradation products of the first reactor were mineralized. In the present work the role of a number of parameters that can have a significant …

A Comprehensive Part Model And Graphical Schema Representation For Object-Oriented Databases, Michael H. Halper

Dissertations

Part-whole modeling plays an important role in the development of database schemata in data-intensive application domains such as manufacturing, design, computer graphics. text document processing, and so on. Object-oriented databases (OODBs) have been targeted for use in such areas. Thus, it is essential that OODBs incorporate a part relationship as one of their modeling primitives. In this dissertation, we present a comprehensive OODB part model which expands the boundaries of OODB part-whole modeling along three fronts. First, it identifies and codifies new semantics for the OODB part relationship. Second, it provides two novel realizations for part relationships and their associated …

Morphological Operations In Image Processing And Analysis, Chamim Christopher Pu

Dissertations

Morphological operations applied in image processing and analysis are becoming increasingly important in today's technology. Morphological operations which are based on set theory, can extract object features by suitable shape (structuring elements). Morphological filters are combinations of morphological operations that transform an image into a quantitative description of its geometrical structure which based on structuring elements. Important applications of morphological operations are shape description, shape recognition, nonlinear filtering, industrial parts inspection, and medical image processing.

In this dissertation, basic morphological operations are reviewed, algorithms and theorems are presented for solving problems in distance transformation, skeletonization, recognition, and nonlinear filtering. A …

Medium Access Control Mechanisms For High Speed Metropolitan Area Networks, Michail Papamichail

Dissertations

In this dissertation novel Medium Access Control mechanisms for High Speed Metropolitan Area networks are proposed and their performance is investigated under the presence of single and multiple priority classes of traffic. The proposed mechanisms are based on the Distributed Queue Dual Bus network, which has been adopted by the IEEE standardization committee as the 802.6 standard for Metropolitan Area Networks, and address most of its performance limitations. First, the Rotating Slot Generator scheme is introduced which uses the looped bus architecture that has been proposed for the 802.6 network. According to this scheme the responsibility for generating slots moves …

On Generalized Adaptive Neural Filter, Zhiqiang Zhang

Dissertations

Linear filters have historically been used in the past as the most useful tools for suppressing noise in signal processing. It has been shown that the optimal filter which minimizes the mean square error (MSE) between the filter output and the desired output is a linear filter provided that the noise is additive white Gaussian noise (AWGN). However, in most signal processing applications, the noise in the channel through which a signal is transmitted is not AWGN; it is not stationary, and it may have unknown characteristics.

To overcome the shortcomings of linear filters, nonlinear filters ranging from the median …

A High-Temperature Pressure Sensor Utilizing Linear Voltage Differential Transformer (Lvdt) And Silicon Wafer-To-Wafer Fusion Bonding Technologies, Robert Sylvester Okojie

Theses

A novel high-temperature pressure sensor was designed based on the principle of magnetic induction. The device is meant to correct the problems inherent in conventional Solid-State pressure transducers such as piezoresistive and capacitive at temperatures above 300°C. Prominent among these problems are increased leakage current, reduced absolute sensitivity, redistributed impurity concentration profile, and thermal mismatch.

This thesis combined the Biot Savart magnetostatic principle and the theory of deflecting clamped circular plates to obtain the microelectromechanical relationship. The problem of thermal mismatch was resolved by the symmetrical layering of a Si₃N₄/TaSi₂/Si₃N₄ sandwich, …

Magnetohydrodynamic Behavior Under Current Impulse Excitation, Shi Wu

Theses

The effects of magnetic field on magnetohydrodynamic (MHD) channel flow between two parallel plates of infinite extent are investigated. The applied magnetic field is due to an infinite impulse current-carrying conductor located a small distance below the lower channel wall. Influence of the induced magnetic field, such that the magnetic Reynolds number (R_m) is less than unity but greater than zero, is included. The solution is obtained using the perturbation theory in the expansion of the field components in a double-power series in R_m and I. Calculations for the magneto-fluid components were carried out using personal computer. …

Design, Fabrication And Characterization Of Infrared Filters, Samiul Amin

Theses

In-situ temperature monitoring, mapping, and control have become significant in semiconductor processes. Temperature of these processes can be measured by making use of the thermal emission from substrates in the infrared region. Various methods have been proposed to provide multicolor infrared detection. One such method involves placing segmented infrared filters close to the focal plane. The present study aims at gaining an insight into the design, fabrication and characterization of infrared filters. Filters were designed and fabricated with peak transmission at 1.5, 3.0, and 4.5 m. Extensive spectroscopic studies, using FTIR spectroscopy, have been performed in the infrared region, on …

Characterization Of Three-Dimensional Shear Flows, Kurra Bhaswan

Theses

This work investigates techniques to analyze and characterize the presence of microstructure in moderately dilute three-dimensional shear flows. In three dimensional shear flows, a distinct structure develops as the coefficient of restitution is lowered with the particles exhibiting a strong tendency towards the formation of clusters. There exists a need to automatically detect and characterize this microstructure in the given flow. Several methods are examined for effective characterization of the microstructure. The techniques employed are based on the classification of the data based on the properties of the Voronoi diagram constructed from the positional parameters of the two-dimensional slices of …

Traffic Management Of A Satellite Communication Network Using Stochastic Optimization, Ambalavanar Arulambalam

Theses

The performance of nonhierachial circuit switched networks at moderate load conditions is improved when alternate routes are made available. However, alternate routes introduce instability under heavy and overloaded conditions, and under these load conditions network performance is found to deteriorate. To alleviate this problem, a control mechanism is used where, a fraction of the capacity of each link is reserved for direct routed calls.

In this work, a traffic management scheme is developed to enhance the performance of a mesh-connected, circuit-switched satellite communication network. The network load is measured and the network is continually adapted by reconfiguring the map to …

Detection Of Planar Facets In Noisy Range Images, Ajey S. Atre

Theses

Segmentation of the image is one of the major tasks of a machine vision system designed for constructing a three-dimensional representation of the object being imaged. A robust approach for segmenting planar surfaces from range images is presented in this paper. An algorithm based on clustering through fuzzy covariance matrices, which has been proposed by Gustafson and Kessel is considered for planar segmentation. However this algorithm performs poorly if the data is noisy, which is usually the case in real life applications. In order to handle noisy data, a robust modification, based on the "noise clustering" concept, is introduced to …

Model Parameter Identification Of The Oscillatory Potential In The Electroretinogram, Sung Hoon Jang

Theses

A mathematical model of the oscillatory potential which may be a useful clinical tool to diagnose the progression of diabetic retinopathy. The model has been investigated by compressing from oscillatory potential into three parameters which contain most of the information for the oscillatory potential data.

About thirty subjects including both normal and diabetic subjects were investigated in this study. Comparing normal and diabetic subjects, we found amplitude parameter was most important factor to classify subjects by normal and diabetic.

Since modeling of the oscillatory potential and the estimation of the model parameters were our final goal, we haven't proposed to …

Simplification Of The Generalized Adaptive Neural Filter And Comparative Studies With Other Nonlinear Filters, Henry Steven Hanek

Theses

Recently, a new class of adaptive filters called Generalized Adaptive Neural Filters (GANFs) has emerged. They share many characteristics in common with stack filters, include all stack filters as a subset. The GANFs allow a very efficient hardware implementation once they are trained. However, there are some problems associated with GANFs. Three of these arc slow training speeds and the difficulty in choosing a filter structure and neural operator.

This thesis begins with a tutorial on filtering and traces the GANF development up through its origin -- the stack filter. After the GANF is covered in reasonable depth, its use …

Development Of An Intelligent Geometry Measurement Procedure For Coordinate Measuring Machines, Tae-Sung Kim

Theses

A Coordinate Measuring Machines (CMM) is a highly accurate electronic scale for the automatic measurement of 2 and 3 dimensional geometries. In a typical operation the CMM measures a set of user defined points, and then utilizes some internal logic to ascertain whether the inspected part meets the specifications. CMMs have received widespread acceptance among the manufacturing community, and in many instances are required as per supplier contract. Applications of CMMs vary from the measurement of simple 2D parts to complex 3D spatial frames (as for example in their use to measure the integrity of automobile frames). The primary objective …

Modeling Of Rapid Thermal Processing System By Finite Element Method, Helen Martynov

Theses

A finite element model for the Rapid Thermal Processing (RTP) system at NJIT was developed based on the software package MSC/NASTRAN. Based on this model, a thermal analysis of the 9" chamber, 3 zones (37 lamps) RTP system was conducted for various modes of system operation with the 6" silicon wafer temperature varying from 300°K to 1100°K. An open-loop control algorithm was developed in order to study the dependence of wafer temperature on time, position, and applied radiant heat distribution. It was shown that the non-uniformity in the radial temperature profile can be less than 3°C during wafer heating at …

Optimization Of Flow In The Collecting Duct During The Concentrating Mode And The Diluting Mode In A Nephron Population Of Two Different Length With The Renin Angiotensin System And Adh Mechanism, Sivakumar Subramanian

Theses

Our present study is to find out how the short and long nephrons are interacting in the human kidney to adjust the flow in the collecting duct to have the maximum flow during the diluting mode and minimum flow during the concentrating mode. The best lengths for the short nephron and long nephron are calculated during the concentrating mode and the diluting mode by using the Newton-Raphson method. If one wants the kidney to perform only the above mentioned functions, a design criteria for an artificial kidney has been proposed. These studies have provided qualitative information regarding the concentrating mechanism …

Finite-Element Ray Tracing, Yong-Chun Liu

Theses

The interesting acoustic modeling problems often push the practical limits of full-wave models. For instance, in acoustic tomography one needs to be able to predict the propagation of an acoustic pulse for successive realizations of 31) environments. For these types of problems ray methods continue to be attractive because of their speed. Unfortunately, existing codes are prone to a number of implementation difficulties which often degrade their accuracy.

As a result most ray models are actually incapable of producing the ray theoretic result. We discuss a. new method for implementing ray theory that uses a. finite-clement formulation. This method is …

Investigation Of Reaction Kinetics Of Hydrogen Chloride With Calcium Oxide By Fourier Transform Infrared Spectroscopy, Maosheng Li

Theses

The kinetics of HCl reaction with CaO was investigated over the temperature range of 148 to 400 °C. A thin film of CaO was deposited on quartz wool and used as the sorbent. The HCl concentration was maintained uniformly in the closed system with a circulating pump in order to minimize the effects of the bulk mass transfer and pore diffusion. The HCl concentration was continuously monitored in a FT-IR cell and the HCl and H₂O spectra were collected automatically by GC software at 1.2 second intervals. In this way, fewer errors were introduced into the system. The …

Agitation Requirements For Complete Liquid Dispersion In Liquid-Liquid-Gas Systems, Emad Ahmad Abu-Hakmeh

Theses

A number of studies have been published in the literature on the determination of the agitation intensity at which two immiscible liquids become completely dispersed in mechanically agitated vessels. However, no information is currently available on the agitation intensity required for the complete dispersion of two liquids in the presence of an additional gas phase. Therefore, the main objective of this study was to experimentally determine the minimum agitation speed for complete liquid-liquid dispersion, N_cd, in liquid-liquid-gas systems as a function of gas flow rate, impeller type, impeller size, and impeller off-bottom clearance. The minimum agitation speed was …

Nitric Oxide Absorption From Flue Gas With Cumene Hydroperoxide Solution, Chung-Der Chen

Theses

The absorption of nitric oxide from gas streams with cumene hydroperoxide (CHP) in n-hexadecane (cetane) as the scrubbing solution was investigated. The efficiency of the scrubbing solution to remove nitric oxide was evaluated over the temperature range of 90 to 110°C, concentration range of 0.1 to 0.5M, and residence time of 12 to 80 seconds. The products were analyzed by gas chromatography (GC), Fourier transform infrared spectroscopy (FTIR), and ion chromatography (IC). The goal of this research was to determine the NO removing efficiency of cumene hydroperoxide solution, a relatively inexpensive tertiary organic hydroperoxide. Also, a possible reaction mechanism for …

Performance Of The Stirling Cycle Thermal Regenerator, Cesar A. Cravo

Theses

Most of the methods developed to analyze the performance of regenerators make assumptions which are not valid in Stirling cycle regenerators. To more adequately describe the conditions of an actual Stirling cycle regenerator a more complex method has been investigated. This method takes into account the time dependence of the mass flow and pressure fluctuations and considers the temperature dependence of the thermophysical properties.

The solution is accomplished by finite difference techniques. The solution determines the temperature distributions of the gas and matrix along the length of the regenerator and calculates the effectiveness over a cycle. A wide range of …

Rigorous Te Solution To The Staircase Model Of The Dielectric Wedge Antenna, Wan-Yu Chen

Theses

The rigorous TE solution to the staircase model of the dielectric wedge antenna is presented. The fundamental, even TE surface wave mode of the dielectric slab waveguide is taken to excite a dielectric wedge which is formed by symmetrically tapering the slab. The method of solution is based on Marcuse's step-transition method. Radiation patterns of power gain are presented which show increased maximum power gains and narrower main lobe beamwidths for longer wedges. For higher dielectric constant material, the main lobe beamwidth is increased. In all cases examined, negligible sidelobes were obtained.

Computer Assisted Molecular Modeling Of Thymidine Nucleoside Analog Inhibitors Of Hiv-1 Reverse Transcriptase, Mark A. Fisher

Theses

An active analog approach to receptor mapping was used to identify the three dimensional structural characteristics associated with a series of thymidine nucleoside analog inhibitors of HIV-1 reverse transcriptase (RT) that may be essential for their activity. Atomic substitutions at the 5 and 3' positions of nucleoside analogs confer global structural and electrostatic changes that result in either increased or diminished inhibitory activity. From a structural perspective, the activity differences can be attributed to the presentation of select atoms in three dimensional motifs that are common to all active compounds and absent or distorted in inactive/poorly active compounds.

The identification …