Engineering Commons^™

Investigation Of Stagnation Flow Heat Transfer For A Heated Horizontal Round Plate, Ching-Hua Wei

Dissertations

The heat transfer characteristics in stagnation flow are investigated through three cases in this study. The first is forced convection by an array of air jets; the second is free convection of a downward-facing heated round plate; the third is free convection of an upward-facing heated round plate.

The first case is investigated by systematic experiments which examine the heat transfer characteristics mainly by five air jets impinging normally to a flat plate, with varying nozzle diameters, and Reynolds numbers, at different distances between the nozzles and the plate. The empirical formulas of heat transfer around the stagnation point and …

Kinetic Studies On Pyrolytic And Oxidative Decomposition Of Chlorocarbons In A Tubular Flow Reactor, Yang Soo Won

Dissertations

Chloroform decay and product distributions were distinctly different in the absence and presence of added O₂ and/or CH₄. Increases in O₂ concentration were observed to speed reagent loss, with a slower decay of chloroform observed for the CHCl₃/CH4/Ar pyrolysis system. In CHCl₃/CH₄/O₂, the major products were C₂Cl4, CH2CCl₂, C₂HCl₃, CO and CO₂ over a wide temperature range. Minor products included CH₂Cl₂, CH₃Cl, and C2H₃Cl. When CH₄ reactant was not present, …

Development Of A Classification And Coding System For Computer-Aided Process Planning, Shilpan K. Patel

Theses

The chore of this work was to develop a Group Technology Classification Code which can represent the full gamut of simple, rotational parts. The automated coding plan is developed to alleviate the endeavor of the process planner to plan the tasks related to the manufacturing of a specific part. The 15 digits were devised from the Japanese KK-3 Classification and Coding system. The KK-3 System contains 21 digits. Our aim is to minimize the code length, and concurrently to eliminate the redundancies. As a result, a 15 digit G.T. Code is created. The proposed plan also generates the operation logic …

Task Scheduling For Fms Based On Genetic Algorithm, Hung-Yuan Li

Theses

A Flexible Manufacturing System (FMS) consisting of p automated guided vehicles (AGV's), m workstations and n tasks is studied. The main problem investigated in this thesis is to find an optimal or suboptimal task scheduling for p AGV's among m workstations to complete n tasks.

An efficient approach based on genetic algorithms has been designed and implemented to solve the problem of task scheduling for a FMS. Near-optimal, or even optimal, task scheduling is accomplished by genetic algorithms. Simulation results on the algorithm are also discussed.

Implementation Of Automated Assembly, Kang H. Kong

Theses

Research has shown that about 60 - 80% wealth producing activities is related to manufacturing in major industrial countries.

Increased competition in industry has resulted in a greater emphasis on using automation to improve productivity and quality and also to reduce cost.

Most of the manufacturing works such as machining, painting, storage, retrieval, inspection and transportation have changed to automation successfully, except assembly. Manual assembly is predominant over automatic assembly techniques due to inherent assembly problem and the fact that the assembly machines lack the innate intelligence of human operator and lack sufficient flexibility to changeover when product designs and …

Simulation Of Voice And Data Integration, Urmila S. Patel

Theses

A simulation model of integrated voice and data is developed. The data packets are transmitted during voice inactivity (i.e. silence duration). A statistical model of voice (talkspurt) and silence duration is generated. inter-arrival time between data packets is modeled using geometrical distribution. The data traffic statistics is simulated for a given voice activity model and various data packet arrival rates. Four important results are obtained by performing this simulation: 1. Average data packet delay versus arrival rate. 2. The optimal ratio of data packet arrival rate to average data packet delay. 3. Probability of wait time for various data packet …

Design For Manufacturability, Kocherlakota Sreedhar

Theses

Design for Manufacturability represents a new awareness of the importance of design as the first manufacturing step. It recognizes that a company cannot meet all its objectives with isolated design and manufacturing operations. The Design for Manufacturability approach embodies certain underlying imperatives that help maintain communication between all components of the Manufacturing and Design system and permit flexibility to adopt and to modify design during each stage of the product realization. Design for Manufacturability cannot be bought or sold and it should be implemented by management. Complete support of management to the implementation is very important to the success of …

The Application Of Adaptive Step-Size Control In The Numerical Simulation Of Calcium Release In Vascular Smooth Muscle, Michael John Sydor

Theses

An algorithm for the adaptive control of numerical integration step-size is developed and implemented for the simulation of a three compartment model for Vascular Smooth Muscle. The three compartment model accounts for the simultaneous diffusion of Ca, ⁴⁵Ca, EGTA, Ca-EGTA, and ⁴⁵Ca-EGTA, and is an extension of a two compartment model by Diecke for the simultaneous diffusion of Ca, EGTA, and Ca-EGTA. The addition of the third compartment is to account for the presence of the Sarcoplasmic Reticulum which stores the calcium needed for contraction and is the primary regulator of calcium in the VSM cell. The SR …

Charcoal Catalyzed Ozone Decomposition Of Organic Pollutants In Water, Kin Ho

Theses

A laboratory study has been performed on the wastewater treatment (destruction of organic species in water) using a novel process called Integrated Adsorption-Oxidation (IAO) where activated carbon is being utilized as a catalyst-adsorbent, and ozone as oxidant. The results of ozonation alone on the pollutants in water are also reported to provide a comparison with the adsorption-oxidation scheme in semi-batch reactions. All experiments were conducted at room temperature in a semi-batch reactor using five (water soluble) representative chemicals as pollutants: Aniline, Acetamide, Pyridine, N,N-dimethyl formamide and O-cresol. We also studied two volatile compounds: Trichloroethylene and Chloroform. Phenol was studied in …

Synthesis And Characterization Of Lpcvd Silicon Carbide Thin Films For X-Ray Lithography, Mahalingam Bhaskaran

Theses

Amorphous silicon carbide thin films were fabricated using low pressure chemical deposition method with a single liquid precursor, di tertiary butyl silane. The films were deposited for a temperature range of 500-850°C and at different pressures ranging from 0.05 to 1 torr. The growth rate of the films deposited at constant pressure of 0.2 torr with a flow rate of 60 sccm, was found to follow an Arrehenius Behavior in the temperature range of 600 - 675°C, yielding an activation energy of 32.5 k cal mol^-1 . IR spectroscopic study showed an absorption peak centered at 780 cm^{-1 …}

Application Of Non-Imaging Optical Inspection To The Detection Of Pinhole Defects In Latex Condoms, Paul Micha Gelencser

Theses

An optical technique was demonstrated for the detection of pinhole defects in latex condoms. To evaluate the optical inspection concept, a prototype inspection apparatus was constructed. In order to maximize contrast between pinhole transmitted signal and optical signal transmitted through the latex condom material, ultraviolet (u.v.) light of wavelength 253nm has been used. This inspection was performed during rotation of the condom, with the light source inside the condom and the photomultiplier photodetector outside. The form on which the condoms were mounted was made of quartz in order to allow the u.v. light to be transmitted through it.

Background signal …

The Neural Network Based Control System For Dynamic Channel Allocation In Pcn Communications, Ching-Yao Huang

Theses

A neural network based control system (NNCS) is adopted in this paper to conduct the channel allocation task in the personal communication networks (PCN). Binary adaptive resonance theory (ART-1) that was modified for pattern matching and provided the corresponding responses is selected as the basic algorithm for the system. Digital portable radio technology can provide reliable access to high quality wireless service for many users. Low power transmission requirement and small cell size configuration that can support more users and diverse services than cellular radio system are the attractive attributes of PCN. Assigning multiple time slots to a user in …

Automatic Infrared And Visual Inspection Of Solder Joints On Pcbs, Jiang Huang

Theses

This thesis reports the research results of automatic inspection of solder joints on printed circuit boards (PCBs). The previous work on this regard has been advanced significantly in the following three aspects. With the application of some microlens and the principle of geometric optics solder joints of real size are inspected in this work instead of larger simulation solder joints in the previous work. A new set of features is formulated and used for infrared inspection. Consequently, better results have been achieved in this work.

Reasonably good results demonstrate the capability of infrared inspection of solder joints on PCBs. Once …

Direct Recovering Of Composite Surface Using Uoff, Zhesheng Huang

Theses

The research work reported in the thesis is motivated by the problem raised in the computer vision area. It utilizes direct method to recover surface structure of objects in 3-D space from a pair of stereo images. The direct method, compared with optical flow-based approach and feature-based approach, is robust and computationally efficient. However it can only recover planar surface structure so far. A new approach to recover structure from a pair of stereo images based on unified optical flow field (UOFF) is developed recently. It can recover curved surface structure.

In this thesis, the problem of recovering surface structure …

A Cmos Logic Circuit To Reduce Substrate Current/Hot Carrier Effect, Tejinder K. Jaswal

Theses

A new C-MOS NAND and CMOS full adder logic circuits which reduces hot carrier problems are discussed. The application of new circuit lowers the channel electric field in N-MOSFET during switching transient and leads to suppression of the N-MOSFET substrate current. The simulation results shows that about 3.99 and 3.75 times smaller peak substrate current are obtained in C-MOS NAND and adder with new circuit compared to the conventional logic circuits. These logic circuits also gives better noise and shows shorter rise and fall times. The new concept provides highly reliable logic circuits without any change of device structure or …

Expert System For Blown Film Extrusion, Jiachyi Li

Theses

Expert systems and blown film extrusion are two subjects to deal with in this thesis. Expert systems are an aspect of artificial intelligence, or a computer's ability to think. The determination of a suitable expert system for particular problem is an important factor in current societies. Blown film is extruded as a continuous tube which is air cooled, collapsed, and wound onto a roll as a double layer of film. Such film, if heat sealed and perforated, makes a roll of bags. There are many factors that affect blown film extrusion. Therefore, using expert system to evaluate blown film extrusion …

Application Of Expert System For Control Of Heating Distribution Network : A Case Study, Jun Li

Theses

The use of an expert system for the heating distribution network is an application of artificial intelligence to the domain of energy engineering.

The development of an expert system for a heating distribution network is explained. The expert system is implemented through the software Kee. The expert system is used to monitor the heating distribution network, and to complement some functions of the controls such as balancing the system pressure, stabilizing output, in addition to fault diagnosis, system process simulation. It serves also as a medium to system moniting, and operator training. Many other functions will be developed on the …

Synthesis And Characterization Of Boron Nitride Masks For X-Ray Lithography, Venkat Paturi

Theses

Boron nitride thin films were deposited on silicon and fused quartz substrates by low pressure chemical vapor deposition using liquid precursor source consisting of Triethyl amine borane complex over a temperature range of 600-900°C. In the range of 600-800°C, the deposition rate, measured at a constant pressure of 0.35 Torr and flow rate of 30 sccm, was observed to follow an Arrhenius behavior yielding an activation energy of 11 kcal/mol. In the temperature range of 800-900°C, the addition of ammonia to Triethylamineborane complex produced films that are stoichiometric, as estimated by RBS measurements, and hydrogen free as determined by Infrared …

Genetic Algorithm For Solving Printed Circuit Board Assembly Planning Problems, Hermean Wong

Theses

The application of the genetic algorithm for solving the planning problems for various printed circuit board assembly machines is presented. The genetic algorithm finds the sequence of component placement/insertion and arrangement of feeders simultaneously, for achieving the shortest assembly time. Three types of assembly planning problems are modeled such that they can be solved by the genetic algorithm. The algorithm uses links (parents) to represent possible solutions and applies genetic operators to generate new links (offspring) in an iterative procedure to obtain the optimal solution. Some examples are provided to illustrate the solutions generated by the genetic algorithm, and these …

A New Approach To Motion Analysis From A Sequence Of Stereo Images, Lin Zhou

Theses

A new approach to motion analysis from a sequence of stereo images is presented in this thesis. Based on a four-frame model, a new concept of unified optical flow field has been developed recently [3]. It is a generalization of the optical flow in stereo imagery. A set of fundamental equations is established to characterize the unified optical flow field. Another set of equations is then derived from which 3-D motion can be reconstructed via the use of the field quantities of the unified optical flow field. In this thesis, the implementation of the approach is conducted. The simulation and …

Interfacing Plasticating Extruders With Personal Computers For Data Acquisition, Information Analysis And Retrieval Purposes, Gautamkumar Y. Shah

Theses

The current manufacturing industries are influenced more and more by computers and automation. Two of the major areas of computer uses are data acquisition and interfacing, both lead towards automation.

The intent of this thesis is to focus on the area of interfacing personal computers with plasticating extruders for information retrieval and storage. The requirements for software and hardware are discussed. Analysis of the stored information can be used to improve the quality of the final product. Implications of the stored parameters on the final product are also discussed. A sample program to store and retrieve the important parameters is …

Novel Artificial Dielectric Plannar Waveguides, Jialing Yang

Theses

An artificial dielectric is a composite material consisting of a dielectric with a large number of conducting particles arranged in a three-dimensional pattern. The particle dimensions are smaller than the optical wavelength of interest. In this thesis, the theoretical and experimental results of some novel artifical dielectric planar waveguide structures are presented. By comparing near field intensity profile measurements from various waveguide structures, we have shown that by adding small clusters of the conductor material into the waveguide we can tailor the mode profile of the waveguide. Also, we were able to fabricate waveguides on a substrate with relatively higher …

Design For Assembly : Re-Design Of An Electrical Switch For The Ease Of Automatic Assembly, Achyuta Reddy Pannala

Theses

A design for assembly (DFA) method is used to analyze the existing design of parts of an electrical switch, and to reduce and re-design them, for the ease of automatic assembly. The procedure for the selection of suitable and economical assembly method is presented based on the Boothroyd & Dewhurst methods. Analysis of the initial design for manual assembly and the re-design for automatic assembly are presented. An algorithmic approach for simplified generation of all mechanical assembly sequences and selecting the good assembly sequences is presented with graphical representations. A work station needed for the automatic assembly is developed, which …

Development Of An Adaptive Fuzzy Shell Clustering Algorithm And Validity Measures, Kurra Bhaswan

Theses

In objective functional based fuzzy clustering algorithms the weighted sum of the distances of the feature vectors from cluster prototype are minimized. The fuzzy memberships are utilized as weighing factors. The cluster prototype can be a point or a line or a plane, etc. This work extends the recent concept of using curved prototypes by utilizing the Adaptive Norm Theorem proposed by Dave¹ to develop an algorithm for the detection of fuzzy hyper-ellipsoidal shell prototypes. The Objective functional associates a norm for each cluster in which to measure the proximity of the shell prototype adaptively. The resulting implementation necessitates …

Petri Net Modeling And Analysis Of An Fms Cell, Paresh A. Patel

Theses

Petri nets have evolved into a powerful tool for the modeling, analysis and design of asynchronous, concurrent systems. This thesis presents the modeling and analysis of a flexible manufacturing system (FMS) cell using Petri nets. In order to improve the productivity of such systems, the building of mathematical models is a crucial step.

In this thesis, the theory and application of Petri nets are presented with emphasis on their application to the modeling and analysis of practical automated manufacturing systems. The theory of Petri nets includes their basic notation and properties. In order to illustrate how a Petri net with …

Adiabatic Kinetic Studies Of The Cytidine/Acetic Anhydride Reaction By Utilizing Temperature Versus Time Data, Joseph John Shatynski

Theses

It is possible to predict the kinetics of a reaction by using temperature versus time data under adiabatic conditions. This method was used for the cytidine/acetic anhydride reaction using a RC1 Mettler Reaction Calorimeter.

The authenticity of the experimental adiabatic system was verified by determining the kinetic parameters of a known reaction (hydrolysis of acetic anhydride) and comparing them to literature values.

For example, the average experimental activation energy, heat of reaction, and ln k₀ values for the hydrolysis of acetic anhydride were 11.2 ±.5 kcal/gmole, -14.4 ± .2 kcal/gmole, and 12.74 ± .94 sec^-1, respectfully, while …

Performance Analysis Of Symbol Timing Recovery Circuits Employed In Digital Communications Systems, Elisha Yegal Bar-Ness

Theses

An analytical approach is presented for the jitter performance of a timing recovery circuit consisting of a prefilter, a zero-memory nonlinear device, and a narrow band postfilter tuned to the pulse repetition frequency. Assuming first a squarer type of nonlinearity, analytical expressions for the rms jitter in the timing wave are obtained as a function of the pre and post filtering characteristics. These expressions are suitable for judging the case where the baseband signal is bandlimited. Also for some specific examples, the jitter performance of this kind of STR circuit is evaluated.

Secondly, a general type of nonlinerity is assumed, …

Multistage Interconnection Networks : Improved Routing Algorithms And Fault Tolerance, Kuo-Yu Chen

Theses

Multistage interconnection networks for use by multiprocessor systems are optimal in terms of the number of switching element, but the routing algorithms used to set up these networks are suboptimal in terms of time. The network set-up time and reliability are the major factors to affect the performance of multistage interconnection networks. This work improves routing on Benes and Clos networks as well as the fault tolerant capability. The permutation representation is examined as well as the Clos and Benes networks. A modified edge coloring algorithm is applied to the regular bipartite multigraph which represents a Clos network. The looping …

Dynamic Analysis Of The Generalized Slider Crank, Sahidur Rahman

Theses

A numerical technique is used to analyze the kinematics of the generalized slider crank mechanism and an analytical technique to derive dynamic force equations for that mechanism has been formulated. The numerical technique used for displacement analysis is based on a combination of Newton-Raphson and Davidon-Fletcher-Powell optimization algorithm using dual-number coordinate-transformation matrices. Velocity analysis is performed by using a dual number method. Finally, dynamic force analysis is accomplished on the basis of the dual-Euler equation and D'Alembert's principle. The approach is developed in such a manner that a digital computer can detect when a solution is possible and then solve …

Off-Line Programming Using Igrip, Narahari K. Bhandary

Theses

AT&T's FWS-200 (Flexible Work Station) has been modeled and simulated to implement Off-Line Programming (OLP). IGRIP (Interactive Graphics Robot Instruction Program) from Deneb Robotics, Inc. has been used to simulate the FWS operation.

A GSL(Graphics Simulation Language) program has been used to simulate the chip placements during PCB assembly. The program leads the user through the motions of chip placement, and after the simulation run downloads the motion sequence to the FWS. The animation sequences of the FWS have been downloaded to the FWS on the Factory Floor using a C program, which is utilized to communicate the data to …