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Articles 179281 - 179310 of 197988

Full-Text Articles in Engineering

Performance Analysis Of Doa Estimation Algorithms Using Physical Parameters, Hui Liu Jan 1992

Performance Analysis Of Doa Estimation Algorithms Using Physical Parameters, Hui Liu

Dissertations and Theses

Analytical performance analysis on Direction-Of-Arrival (DOA) estimation algorithms has attracted much excellent research in recent years, various statistical properties have been revealed. However, in most of these analyses, insights of the performance were masked because of the involvement of singular values and singular vectors which depend on the character of the algorithms and data structures in a complex and nonlinear manner.


Characterization Of Quantization Noise In Oversampled Analog To Digital Converters, Eric W. Multanen Jan 1992

Characterization Of Quantization Noise In Oversampled Analog To Digital Converters, Eric W. Multanen

Dissertations and Theses

The analog to digital converter (ADC) samples a continuous analog signal and produces a stream of digital words which approximate the analog signal. The conversion process introduces noise into the digital signal. In the case of an ideal ADC, where all noise sources are ignored, the noise due to the quantization process remains. The resolution of the ADC is defined by how many bits are in the digital output word. The amount of quantization noise is clearly related to the resolution of the ADC. Reducing the quantization noise results in higher effective resolution.


Parameter Uncertainty And Modeling Of Sludge Dewatering In One Dimension, Joseph H. Plaskett Jan 1992

Parameter Uncertainty And Modeling Of Sludge Dewatering In One Dimension, Joseph H. Plaskett

Dissertations and Theses

Separation of liquid from solids is a necessary step in the ultimate disposal of wastewater sludges. Most commonly, sludges are dewatered by pressure-filtration methods. Mathematical models of the physics of the sludge dewatering process would provide the ability to predict dewatering performance and optimize the design and operation of dewatering facilities.


An Experimental Method For Determining Membrane Penetration, Jong W. Choi, Isao Ishibashi Jan 1992

An Experimental Method For Determining Membrane Penetration, Jong W. Choi, Isao Ishibashi

Civil & Environmental Engineering Faculty Publications

A new and simple experimental method is proposed for the determination of membrane penetration due to changes of the effective confining pressure in triaxial and hollow cylinder tests. The proposed method has advantages over existing methods in that it requires neither special devices nor questionable assumptions. It only requires a series of drained isotropic compression tests in a conventional triaxial device with plastic liners. The results from the proposed method are compared to those from several existing experimental and analytical methods.


Measurements Of The Fundamental Thermodynamic Parameters Of Li/Bcx And Li/Socl2 Cells, E. E. Kalu, Ralph E. White, E. C. Darcy Jan 1992

Measurements Of The Fundamental Thermodynamic Parameters Of Li/Bcx And Li/Socl2 Cells, E. E. Kalu, Ralph E. White, E. C. Darcy

Faculty Publications

The thermodynamic data needed to estimate the heat generation characteristics of Li/BCX and Li/SOCl2 cells were determined using two experimental techniques, equilibrium or reversible cell discharge and measurement of open circuitpotential as a function of temperature. The results obtained showed that the reversible cell potential (Er), the temperature dependence of the reversible cell potential (dEr/dT) and thermoneutral potential (Eh) of the BCX cell were respectively, Er,25oc = 3.74 V, dEr/dT = –0.857 ± 0.198 mV/K and Eh = 3.994 …


Thermal Mathematical Modeling Of A Multicell Common Pressure Vessel Nickel-Hydrogen Battery, Junbom Kim, T. V. Nguyen, Ralph E. White Jan 1992

Thermal Mathematical Modeling Of A Multicell Common Pressure Vessel Nickel-Hydrogen Battery, Junbom Kim, T. V. Nguyen, Ralph E. White

Faculty Publications

A two-dimensional and time-dependent thermal model of a multicell common pressure vessel (CPV) nickel-hydrogen battery was developed. A finite element solver called PDE/Protran was used to solve this model. The model was used to investigate the effects of various design parameters on the temperature profile within the cell. The results were used to help find a design that will yield an acceptable temperature gradient inside a multicell CPV nickel-hydrogen battery. Steady-state and unsteady-state cases with a constant heat generation rate and a time-dependent heat generation rate were solved.


Comparison Of Heat-Fin Materials And Design Of A Common-Pressure-Vessel Nickel-Hydrogen Battery, Junbom Kim, Ralph E. White Jan 1992

Comparison Of Heat-Fin Materials And Design Of A Common-Pressure-Vessel Nickel-Hydrogen Battery, Junbom Kim, Ralph E. White

Faculty Publications

A two-dimensional, axisymmetric, and time-dependent thermal model was developed to study the temperature behavior of the cylindrically shaped common-pressure-vessel nickel-hydrogen cell. A differential-energy-balance equation was used as the governing equation. A finite-element software package called PDE/Protran was used to solve this model. Different materials such as copper, copper beryllium, silver, and sterling silver were compared as heat-fin materials. The heat-fin geometry (thickness and height) and spacing were tested to find a design that yielded an acceptable temperature gradient inside a nickel-hydrogen cell. Pulse heat-generation rates were tested and correlated with the time-dependent heat-generation cases.


A Mathematical Model Of A Cuo/Cu Vaporvolt Cell, Makoto Kawanami, Trung V. Nguyen, Ralph E. White Jan 1992

A Mathematical Model Of A Cuo/Cu Vaporvolt Cell, Makoto Kawanami, Trung V. Nguyen, Ralph E. White

Faculty Publications

A new battery named "Vaporvolt"b cell is in the early stage of its development. A mathematical model of a CuO/CuVaporvolt cell is presented that can be used to predict the potential and the transport behavior of the cell during discharge.A sensitivity analysis of the various transport and electrokinetic parameters indicates which parameters have the mostinfluence on the predicted energy and power density of the Vaporvolt cell. This information can be used to decide whichparameters should be optimized or determined more accurately through further modeling or experimental studies. Theoptimal thicknesses of electrodes and separator, the concentration of the electrolyte, and …


Removal Of Mercury From Waste Water: Large-Scale Performance Of An Ion Exchange Process, James A. Ritter, J. P. Bibler Jan 1992

Removal Of Mercury From Waste Water: Large-Scale Performance Of An Ion Exchange Process, James A. Ritter, J. P. Bibler

Faculty Publications

Duolite™ GT-73 ion exchange resin routinely reduces the mercury content of a waste water stream to less than the permitted level of 10 ppb. Effluent concentrations from the ion exchange facility (IEF) are consistently between 1 to 5 ppb, even though the feed contains a varying concentration of mercury (0.2 to 70 ppm). Two operational problems have been encountered at that facility, however. Firstly, the stated capacity of the resin for mercury was not being achieved. The abnormally low capacity was traced to analytical laboratory waste which was intermittently treated by the resin. That waste contained hydrochloric acid, stannous chloride, …


Behavior Of Square And L-Shaped Slender Reinforced Concrete Columns Under Combined Biaxial Bending And Axial Compression, Wen Hu Tsao Dec 1991

Behavior Of Square And L-Shaped Slender Reinforced Concrete Columns Under Combined Biaxial Bending And Axial Compression, Wen Hu Tsao

Dissertations

A numerical analysis was developed to evaluate the complete load-deflection and moment-curvature relationships for square and L-shaped slender reinforced concrete columns subjected to biaxial bending and axial load. This computer model can be used for any cross section geometry and material properties of normal concrete. The analysis was based on a deformation control and both the ascending and descending branches of curves can be studied. The finite difference method was introduced to calculate the deflections which satisfy the compatibility equations. Six square slender columns and eight L-shaped slender columns were tested to compare their experimental load-deformation results with the analytical …


A Generalized, Parametric Pr-Qmf/Wavelet Transform Design Approach For Multiresolution Signal Decomposition, Hakan Caglar Dec 1991

A Generalized, Parametric Pr-Qmf/Wavelet Transform Design Approach For Multiresolution Signal Decomposition, Hakan Caglar

Dissertations

This dissertation aims to emphasize the interrelations and the linkages of the theories of discrete-time filter banks and wavelet transforms. It is shown that the Binomial-QMF banks are identical to the interscale coefficients or filters of the compactly supported orthonormal wavelet transform bases proposed by Daubechies.

A generalized, parametric, smooth 2-band PR-QMF design approach based on Bernstein polynomial approximation is developed. It is found that the most regular compact support orthonormal wavelet filters, coiflet filters are only the special cases of the proposed filter bank design technique.

A new objective performance measure called Non-aliasing Energy Ratio(NER) is developed. Its merits …


The Hydraulic Performance Of A Vortex Tube Foector, F Mtaro Dec 1991

The Hydraulic Performance Of A Vortex Tube Foector, F Mtaro

Tanzania Journal of Engineering and Technology (TJET)

The vorle.r tube silt exrrac/or consists of a pipe, rhe crest of which has a slit and lies flush across lhe canal bed.With minimal warer loss, I.oe bedload is extracted through lhe slil settling canal back ro the river, thus reducing or eliminating the bedload transported in main canal. Ihe resulting swirling flow phenomena is of complex nature and depends on sc conirol paramerers, as a result of which previous empirical design approaches have yielded conflicting guidelines. By means Of a simplified hydraulic system, the flow mechanism and energy in rhe can be determined.


Absorption Of Nitrogen Oxides Into Sodium Hydroxide Solution In A Packed Column: Effect Of Gas Flowrate And Temperature, J Katima Dec 1991

Absorption Of Nitrogen Oxides Into Sodium Hydroxide Solution In A Packed Column: Effect Of Gas Flowrate And Temperature, J Katima

Tanzania Journal of Engineering and Technology (TJET)

The effect of gas flow rate and temperature on the absorption rate of nitrogen oxides (NO ) and column absorption eff iciency has been studied using a 2M goåium hydroxide (NaOH) solution in a packed The absorpt ion process was carried out at atmospheric column. pressure, with NOV concentration ranging between 150 and 10000 pp:tt, NO/N02 ratio of O and 1 iquid flow rate of O .8 1/ min. The gas flow rate was varied from 20 to 60 1/17 in and the temperature from 25 to 45 c. It was found that Ehe column absorption efficiency increases with decreasing …


Frictional Resistance Of Geotextiles, Md. Khairul Alam Dec 1991

Frictional Resistance Of Geotextiles, Md. Khairul Alam

Theses

The pullout resistance of geotextiles was examined using pullout tests. A suitable wooden box with large (2 ft x 2 ft x 4 ft) dimensions was used to avoid the effect of boundary and to simulate field conditions. Two types of failure patterns were observed. For shallow embedment (<3 ft), geotextile produced a movement of the surrounding mass of sand in the shape of an inverted cone due to interlocking friction between geotextile and sand particles. The cone angle decreases with increase in depth of embedment. For embedment equal to or greater than 3 ft., no sand cone developed and the failure occurred along the interface of geotextile and sand. For 1 ft. surcharge, the increase in the pullout resistance due to combined horizontal and vertical embedment was about 30 %.


An Implementation Of Bionomial-Qmf For Subband Coding Of Speech, Feng Chen Dec 1991

An Implementation Of Bionomial-Qmf For Subband Coding Of Speech, Feng Chen

Theses

A real-time subband speech codec is implemented by the author on TMS320C25 digital signal processor based hardware for speech compression down to 0.25 bit per sample.

The Binomial Quadrature Mirror Filters (B-QMFs) are employed as the basic block for the hierarchical, dynamic tree, analysis/synthesis filter bank. After the analysis, available bits are optimally allocated among subbands. Band statistics are updated to overcome the nonstationarities of speech signal.

The energy compaction performance of this codec is compared with different subband and DCT in simulations for speech signals and AR(1) source models.

It is shown that the speech codec implemented provides an …


Computer Control For 2-Axis Magnetic Suspension System, Jian Chen Dec 1991

Computer Control For 2-Axis Magnetic Suspension System, Jian Chen

Theses

A two-axis magnetic suspension system. using linear-potentiometer position sensing and DC solenoids, controlled digitally by a 80386 microcomputer has been built and operated in our laboratory. Control algorithms obtained by combining the full-state feedback control law with two methods of estimating velocities are studied. One method uses a nonlinear reduced-order observer; the other uses a finite difference algorithm. The nonlinear reduced-order observer performs better in simulation but the difference algorithm takes less calculation time and is used in the implementation. The system has been operated successfully to suspend weights up to 1.2 lb. and to get a slant angle more …


Minimum-Time Control For Submarine Interception, Zaiping Chen Dec 1991

Minimum-Time Control For Submarine Interception, Zaiping Chen

Theses

This thesis attempts to offer a possible improvement for conventional anti-submarine system which is mounted on warship. It consists of two parts: the control law and its realization concerning the particular problem. The control based on optimal theory is devised for three-dimentional minimum-time interception. A microprocessor system is also designed to achieve all necessary steps to track and attack the target. The thesis focuses on the question of how to launch a group of subcharges to destroy a submarine cruising under water: find the optimal trajectory by developing a numerical method to solve the nonlinear dynamic system and design a …


Influence Of Heavy Metal Concentration On Rotating Biological Contrator Performance, Huei-Sheng Cheng Dec 1991

Influence Of Heavy Metal Concentration On Rotating Biological Contrator Performance, Huei-Sheng Cheng

Theses

Seven heavy metals ( Fe+2, Mn+2, Zn+2, Ag+, Pb+2, Cu+2, Cd+2 ) at various concentrations were investigated in a Rotating Biological Contactor (RBC) system. The experimental data indicated that the degree of heavy metal toxicity in the biological system mainly depended on the ratio of inflow heavy metal concentration to organic loading. The optimal ratio of heavy metal to organic loading was determined on the basis of the maximum removal of chemical oxygen demand (COD) under different operating conditions. In addition, the effect of heavy metal on …


Design And Development Of An Automated Assembly System In A Discrete Manufacturing Environment, Sandeep K. Desai Dec 1991

Design And Development Of An Automated Assembly System In A Discrete Manufacturing Environment, Sandeep K. Desai

Theses

This work is dedicated to extend the technology of automated assembly to include small and thin parts, light in weight. As the parts are thin a problem exists in the feeding process and orientation. The objective of project is to overcome this difficulty. The main theme of this thesis is to reduce labor cost and to improve productivity and quality of assembly operations by introducing low cost automation in the companies having discrete manufacturing environment.

An example of assembly involving a thin part has been selected. Two components from an electrical switch assembly are chosen, namely the spring and rivet. …


Design Of An Advanced Control Algorithm For A Nuclear Power Plant Feedwater Control System, Randall C. Ezzo Dec 1991

Design Of An Advanced Control Algorithm For A Nuclear Power Plant Feedwater Control System, Randall C. Ezzo

Theses

Electric power companies with nuclear power plants have been aggressively looking for ways to increase plant safety and availability by increasing the reliability and performance of the plant's control systems. The performance of the Oyster Creek Nuclear Station's feedwater control system can be significantly improved by replacing the proportional-integral compensator with a compensator based on modern control concepts. In response to a -10 inch reactor water level setpoint change, settling time is improved from 107 seconds with 3% overshoot to 34 seconds with no overshoot.


A Case Study On Petri Net Modeling, Animation, And Simulation, Suresh C. Gurala Dec 1991

A Case Study On Petri Net Modeling, Animation, And Simulation, Suresh C. Gurala

Theses

Petri nets as a graphical tool has developed over the last decade into a suitable model for representing, modeling, designing, analyzing and studying concurrent systems. In this thesis, Petri nets are applied for analyzing, modeling and simulation of a flexible assembly station. An existing AT&T FWS200 flexible assembly workstation for printed circuit board is modeled using Petri nets without the consideration of insertion failures and other abnormalities in the system. The Petri net model is then simulated using Graphics simulation language (GSL).


Advanced Manufacturing Applications Of Cost Estimating Techniques For Metal Cutting Industries, Zubair Hamid Dec 1991

Advanced Manufacturing Applications Of Cost Estimating Techniques For Metal Cutting Industries, Zubair Hamid

Theses

In this work, different cost estimating techniques in metal cutting industry were studied. A basic understanding of estimation concepts were given. The typical breakdown of total cost was also given and discussed in details. Practical applications of cost estimating is studied. The effect of different parameters which relate to the lot sizes or quantity were discussed. All these results show that total cost is minimum at a point which is called least cost point, after that cost increases because of the addition of extra resources, in terms of man, machine and increase in administrative expenses.


Bridge Deterioration Models, Christopher R.H. Howard Dec 1991

Bridge Deterioration Models, Christopher R.H. Howard

Theses

The deteriorated condition of America's bridges raises the need for a proper and optimal method of bridge management, from the conceptual stage through the construction stage, and throughout the useful life of our bridges. State agencies need to expand their data collection process so as to include additional information pertinent to the formulation of a credible system. This is critical in order to accommodate increased research efforts to investigate the behavioral pattern/s of the nations bridges and to eventually optimize bridge management systems. This thesis looks at the bridge deterioration model as a vital tool in realizing more effective bridge …


Liquid-Liquid Dispersion In Agitated Vessels Provided With Multiple Impellers, Yu-Tsang Huang Dec 1991

Liquid-Liquid Dispersion In Agitated Vessels Provided With Multiple Impellers, Yu-Tsang Huang

Theses

Baffled vessels with multiple impellers are widely used in industry to generate liquid-liquid dispersions. In this work, a new method to determine the minimum agitation speed for complete dispersion in two immiscible liquids was developed. This method was conceived to replace the traditional visual observation method that has been extensively used in the past for this purpose. The minimum agitation speeds for liquid-liquid dispersion with single and multiple impellers in baffled vessel were also measured. The effect of a number of variables such as size and type of impellers, size of tank, impeller location, spacing between impellers, and dispersed phase …


Fast Arithmetic Operations On The Hypercube Using Conditional Sum Addition And Modified Booth's Algorithm, Umar Bin Iftikhar Dec 1991

Fast Arithmetic Operations On The Hypercube Using Conditional Sum Addition And Modified Booth's Algorithm, Umar Bin Iftikhar

Theses

Algorithms for fast arithmetic operations (i.e., addition and multiplication) on the hypercube computer are presented. The hypercube network of dimension d interconnects N = 2d processors in such a way that each processor is directly connected to d neighboring processors; m order to communicate between processors, the maximum length of the path is d. The addition algorithm is based on the conditional sum technique. The computational time using this algorithm is O(log2 N+q) where q is the number of the bits per processor in the hypercube of N processors. Operands of size N*q are distributed among the hypercube …


Development Of An Expert System For The Safety Of Workers From Electrical Hazards At Work Place, Faizul Islam Dec 1991

Development Of An Expert System For The Safety Of Workers From Electrical Hazards At Work Place, Faizul Islam

Theses

This thesis presents the development of an expert system for the safety of workers from electrical hazards at work place.

The objective of this work is to show how an expert system within the workplace can be used in helping to create an effective safety program.

An effective expert system for electrical safety have been developed for the workers to prevent accidents from electrical hazards using the safety regulations of Occupational Safety and Health Administration.

The regulations developed by OSHA have been incorporated in rule based expert system which can be accessed by any non computer professional and the system …


Response Characteristics Of Inelastic Single Degree Of Freedom Systems Subjected To Intraplate Earthquakes, Linda C. Jones Dec 1991

Response Characteristics Of Inelastic Single Degree Of Freedom Systems Subjected To Intraplate Earthquakes, Linda C. Jones

Theses

Within recorded, although not recent, history, there have been several large magnitude earthquakes in the Eastern and Central United States and the need to provide measures to protect from potential damage is recognized by the engineering community. Since there are inherent differences between earthquakes that occur along tectonic plate boundaries, interplate, and those that occur within the plate boundaries, intraplate, it is important to understand how these differences impact structural design. A parametric study of single degree of freedom systems subjected to various recorded and artificial ground motions was performed to identify the variations in response characteristics.

It was found …


Stability And Durability Of Large Aggregate Asphalt Concrete, Rais A. Khan Dec 1991

Stability And Durability Of Large Aggregate Asphalt Concrete, Rais A. Khan

Theses

There are many factors which affect the properties of asphalt concrete and one of these is a maximum aggregate size used in the mix. In this study of the effect of maximum aggregate size on Marshall stability, flow and durability of asphalt aggregate mixtures is investigated.

Two different mixes having gradations with maximum aggregate sizes of 3/4 and 1-1/2 inches were considered. The optimum asphalt content for mix having 3/4 inch maximum aggregate size, was determined by the standard Marshall procedure. The optimum asphalt content for the mix having 1-1/2 inch maximum aggregate size, was estimated based on thickness of …


Vision-Guided Servoing Robot Arm System, Shing Lee Dec 1991

Vision-Guided Servoing Robot Arm System, Shing Lee

Theses

This thesis investigate the problem of tracking 2-D circle parts with an eye-in-hand robot arm system. A vision module capable of measuring the motion of a circle is developed. Two algorithms based on the conic equation representation of circle and the symmetric property are developed. The first algorithm approximates the image of the circle as an ellipse. The second algorithm use the arc radius estimator to extract two image points of the circle located at the center of the largest arc. These image points are then used to solve for the inverse perspective transformation. An inverse kinematics solution based on …


Development Of Cellular Manufacturing Systems For Overall Production Efficiency, Srinivas Lokula Dec 1991

Development Of Cellular Manufacturing Systems For Overall Production Efficiency, Srinivas Lokula

Theses

For years the industrial job shop is facing an increase in complexity and decline in productivity due to increase in parts mix, volume of parts, plant size, machine production rates and part complexity. The development of Group Technology and Cellular Manufacturing seeks to eliminate or minimize complexity and to maximize productivity.

Cellular manufacturing is the physical division of job shop's manufacturing machinery into production cells. Each cell is designed to produce parts requiring similar machinery and machine operations. Cellular manufacturing is one of the best manufacturing techniques to support Just In Time manufacturing and Total Quality Management.

This thesis work …