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1998

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Articles 271 - 300 of 1354

Full-Text Articles in Engineering

Studies On The Preparation Of Nanophase Electrode Materials And Its Electrochemical Properties(Ⅲ)—Performance Of Nm-Γ-Mno2 Obtained By Microemulsion Method, Ling Liu, Xi Xia Aug 1998

Studies On The Preparation Of Nanophase Electrode Materials And Its Electrochemical Properties(Ⅲ)—Performance Of Nm-Γ-Mno2 Obtained By Microemulsion Method, Ling Liu, Xi Xia

Journal of Electrochemistry

A nanophase MnO2 was synthesized using w/o microemulsion as reation media, The most favorable experiment conditions for the preparation of nm MnO2 were researched. XRD,TEM,AC impedance, cyclic voltammetry etc. examinations were used to characterize the sample comparison with the classical MnO2 (I.C.No.1EMD,electrolytic manganese dioxide). Sample shows that the crystal styucture of the synthesized samples are mainly γ-MnO2, with average particle size in the nanometer as shown by TEM. It was found that the discharge capacity of nm MnO2 obtained is significantly higher than that of the I.C.No.1 EMD.


Electrooxidation Of Benzene To Benzoquinone In A Packed Bed Reactor, Xin-Sheng Zhang, Ping Ding, Ying-Chun Dai, Wei-Kang Yuan Aug 1998

Electrooxidation Of Benzene To Benzoquinone In A Packed Bed Reactor, Xin-Sheng Zhang, Ping Ding, Ying-Chun Dai, Wei-Kang Yuan

Journal of Electrochemistry

A packed electrode reactor was used to oxidize to benzoquinone. Anode bed of the reactor has a size of 10~30 mm×450 mm×50 mm(thickness×length×width),and was packed porous lead alloy. A dispersion of benzene in 1 mol/L aqueous sulfuric acid was passed through the reactor. Current efficiency for benzoquinone generation is 62.9% at optimal operating condition: velocity of electrolyte flow, 0.19 ms -1 ;current, 10 A; thickness of anode bed, 10 mm, and percentage of benzene, 24%.


Radiation Modulator System, M. Pinar Mengüç, Bruce L. Walcott, Stephen R. Swabb, Michael A. Marra Iii Aug 1998

Radiation Modulator System, M. Pinar Mengüç, Bruce L. Walcott, Stephen R. Swabb, Michael A. Marra Iii

Mechanical Engineering Faculty Patents

A radiation modulator system and related method for actively controlling a flame in a combustion system are provided. The system includes a plurality of radiation modulators positioned adjacent the flame. A sensor arrangement is provided for sensing combustion characteristics of the flame and generating a sensor signal representative of the combustion characteristics. The sensor signal is received in a computer which then generates a control signal for transmission to a linkage arrangement which provides for the repositioning of the radiation modulators. Thus, the flame is actively controlled by continually repositioning the modulators in response to the sensor signal and the …


Performance Of Optimal Trade-Off And Distance-Classifier Circular Filters For Rotation Invariance, Samuel Peter Kozaitis, Sila Thangwaritorn Aug 1998

Performance Of Optimal Trade-Off And Distance-Classifier Circular Filters For Rotation Invariance, Samuel Peter Kozaitis, Sila Thangwaritorn

Electrical Engineering and Computer Science Faculty Publications

We evaluated the performance of circular optimal trade-off SDF (OTSDF) and distance classifier correlation filters (DCCFs) as rotation-invariant correlation filters. Because the filters are designed using different parameters we compared the filter's performance in terms of an equivalent effect of probability of error. The use of OTSDF and DCCF filters as circular filters allows their calculation to be greatly simplified when compared to using rotated views of an object to create filters. We found that both types of filters can be used for rotation-invariant object recognition in a noisy environment. In addition, the filters generated were real-valued so they may …


Signal Monitoring Apparatus For Wavelength Divison Multiplexed Optical Telecommunication Networks, Dennis J. Derickson, Roger Lee Jungerman Aug 1998

Signal Monitoring Apparatus For Wavelength Divison Multiplexed Optical Telecommunication Networks, Dennis J. Derickson, Roger Lee Jungerman

Electrical Engineering

A detector array spectrometer simultaneously monitors wavelength, power, and signal-to-noise ratio of wavelength division multiplexed (WDM) channels in telecommunication networks. A spectrometer spatially separates signals from the WDM channels according to the channels' wavelengths. The separated signals are incident on an array of split-detectors that conforms to the spatial separation of the signals provided by the spectrometer. While the split-detectors are positioned to receive a signal from each WDM channel, a noise detector is positioned between adjacent split-detectors to measure noise. A common mode output from two halves of each split-detector indicates the power in a WDM channel, while a …


Sensor For Rotational Velocity And Rotational Acceleration, Rasheed M.A. Azzam Aug 1998

Sensor For Rotational Velocity And Rotational Acceleration, Rasheed M.A. Azzam

University of New Orleans Patents

Novel rotation sensors are disclosed. sensors with a temporal resolution of one measurement per rotation. A transparent or absorbing substrate can be coated with a transparent thin film to produce a linear response in reflectance versus angle of incidence over a certain range of angles. The best results were obtained when the incident light was s-polarized For example. a Si substrate coated with an SiO2 film was used in constructing a reflection rotation sensor. Experimental results and an error analysis of this rotation sensor are presented.


Urban And Environmental Planning In Nepal, Ambika P. Adhikari Aug 1998

Urban And Environmental Planning In Nepal, Ambika P. Adhikari

Himalayan Research Papers Archive

This collection of essays deals with issues related to housing, and urban and environmental planning in Nepal. Specific focus is on the planning and environmental problems related to the towns of the Kathmandu Valley.

Nepal is facing several challenges in the areas of urban and environmental management and planning . Rapidly increasing population is exerting pressure in all aspects of urban infrastructure, services and housing. Traditional community support and planning systems are breaking apart due to several factors, such as changing societal values, urban consumption patterns and commercialization of traditionally household activities. On the other hand, Nepali society is not …


Shell Cracking In Investment Casting With Laser Stereolithography Patterns, W. L. Yao, Ming-Chuan Leu Aug 1998

Shell Cracking In Investment Casting With Laser Stereolithography Patterns, W. L. Yao, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents an investigation of ceramic shell cracking during the burnout process in investment casting with internally webbed laser stereolithography patterns. We hypothesize that shell cracking will occur when the rupture temperature of the ceramic shell is lower than both the glass transition temperature of the pattern material and the web· link buckling temperature. The hypothesis is validated by our experimental observations which confirm the numerical predictions from our finite element analysis. This provides a basis for design of the internal web geometry of a lithography pattern and evaluation of the burnout process with such a pattern. We show …


Rapid Freezing Prototyping With Water, Wei Zhang, Ming-Chuan Leu, Zhiming Ji, Yongnian Yan Aug 1998

Rapid Freezing Prototyping With Water, Wei Zhang, Ming-Chuan Leu, Zhiming Ji, Yongnian Yan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Rapid Freezing Prototyping (RFP) with water is a novel solid freeform fabrication technique that can generate three-dimensional ice objects by depositing and rapidly freezing water layer by layer. The support where necessary is made of brine whose. freezing point is lower than. pure water. After building the part, the support can be removed by utilizing the melting temperature difference between brine and water. Preliminary experiments have shown that the ice patterns produced by this technique can be used for design visualization and silicone molding. This paper will present the concept and some experimental results of the RFP process as well …


Static Compaction Of Test Sequences For Synchronous Sequential Circuits, Lijie Qi Aug 1998

Static Compaction Of Test Sequences For Synchronous Sequential Circuits, Lijie Qi

Dissertations and Theses

Today, VLSI design has progressed to a stage where it needs to incorporate methods of testing circuits. The Automatic Test Pattern Generation (ATPG) is a very attractive method and feasible on almost any combinational and sequential circuit.

Currently available automatic test pattern generators (ATPGs) generate test sets that may be excessively long. Because a cost of testing depends on the test length, compaction techniques have been used to reduce that length. The motivation for studying test compaction is twofold. Firstly, by reducing the test sequence length, the memory requirements during the test application and the test application time are reduced. …


An Information-Theoretical Approach To The Adaptive Segmentation And Classification Of The Sleeping Electroencephalogram, Russell James Clark Aug 1998

An Information-Theoretical Approach To The Adaptive Segmentation And Classification Of The Sleeping Electroencephalogram, Russell James Clark

Wayne State University Dissertations

Sleep is not a single homogeneous state; it consists of several identifiable states. The states are identified by the electroencephalogram (EEG), electrooculogram, and the electromyogram. The most common classification method consists of six classes labeled: wake, stage 1 through 4, and stage REM. A fixed length of data, usually 20 or 30 second epochs, are analyzed and placed in one of the six categories. An all-nigh sleep recording consists of 900 to 1500 such epochs and the task of scoring a record is tedious. Additionally, much of the detail in the EEG is lost due to the size of the …


Defects And Site Occupancies In Nb-Cr-Ti C15 Laves Phase Alloys, P. G. Kotula, C. B. Carter, Katherine C. Chen, Dan J. Thoma, F. Chu, T. E. Mitchell Aug 1998

Defects And Site Occupancies In Nb-Cr-Ti C15 Laves Phase Alloys, P. G. Kotula, C. B. Carter, Katherine C. Chen, Dan J. Thoma, F. Chu, T. E. Mitchell

Materials Engineering

No abstract provided.


Selection Of Irrigation Methods For Agriculture: Drip/Micro Irrigation, Charles M. Burt Aug 1998

Selection Of Irrigation Methods For Agriculture: Drip/Micro Irrigation, Charles M. Burt

BioResource and Agricultural Engineering

The ASCE On-Farm Committee has recently completed a draft of a manual (Bliesner et al, 1998) on "Selection of Irrigation Methods for Agriculture." One of the chapters describes drip/micro irrigation methods. Numerous variations of drip/micro designs are discussed, along with advantages and disadvantages. This paper provides an overview of some aspects of that chapter.


Ccfss Technical Bulletin August 1998, Wei-Wen Yu Center For Cold-Formed Steel Structures Aug 1998

Ccfss Technical Bulletin August 1998, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.


Acuta Enews August 1998, Vol.27, No. 8 Aug 1998

Acuta Enews August 1998, Vol.27, No. 8

ACUTA Newsletters

In This Issue

Annual Conference Highlights

Board Report

Tek-Futures: Leading-Edge Technologies for the 21st Century

DC at a Glance

Positions Available

Welcome New Members


Ccfss News August 1998, Wei-Wen Yu Center For Cold-Formed Steel Structures Aug 1998

Ccfss News August 1998, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.


Measured Ceiling Fan Performance And Usage Patterns: Implications For Efficiency And Comfort Improvement, Florida Solar Energy Center, Jeffrey Sonne Aug 1998

Measured Ceiling Fan Performance And Usage Patterns: Implications For Efficiency And Comfort Improvement, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

Simulations suggest residential cooling energy use can be reduced up to 15% through the use of ceiling fans with thermostat set-up. However, monitoring data from a large scale study of Florida homes found that air conditioning consumption was not lower because thermostats settings were not raised in response to fan use, and many fans were apparently left on for long periods in unoccupied zones. To further study these findings, we collected field data on actual ceiling fan usage patterns and how they might be affected by education. We also studied power characteristics and air moving efficiency of current generation ceiling …


Possible New Directions In Mathematical Foundations Of Fuzzy Technology: A Contribution To The Mathematics Of Fuzzy Theory, Hung T. Nguyen, Vladik Kreinovich Aug 1998

Possible New Directions In Mathematical Foundations Of Fuzzy Technology: A Contribution To The Mathematics Of Fuzzy Theory, Hung T. Nguyen, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.


Uncertainty Representation Explains And Helps Methodology Of Physics And Science In General, Misha Kosheleva, Vladik Kreinovich, Hung T. Nguyen, Bernadette Bouchon-Meunier Aug 1998

Uncertainty Representation Explains And Helps Methodology Of Physics And Science In General, Misha Kosheleva, Vladik Kreinovich, Hung T. Nguyen, Bernadette Bouchon-Meunier

Departmental Technical Reports (CS)

No abstract provided.


How To Describe Partially Ordered Preferences: Mathematical Foundations, Olga Kosheleva, Vladik Kreinovich, Hung T. Nguyen, Bernadette Bouchon-Meunier Aug 1998

How To Describe Partially Ordered Preferences: Mathematical Foundations, Olga Kosheleva, Vladik Kreinovich, Hung T. Nguyen, Bernadette Bouchon-Meunier

Departmental Technical Reports (CS)

No abstract provided.


Cooperative Learning Is Better: Explanation Using Dynamical Systems, Fuzzy Logic, And Geometric Symmetries, Vladik Kreinovich, Edye Johnson-Holubec, Leonid K. Reznik, Misha Kosheleva Aug 1998

Cooperative Learning Is Better: Explanation Using Dynamical Systems, Fuzzy Logic, And Geometric Symmetries, Vladik Kreinovich, Edye Johnson-Holubec, Leonid K. Reznik, Misha Kosheleva

Departmental Technical Reports (CS)

No abstract provided.


Towards Formalization Of Feasibility, Randomness, And Commonsense Implication: Kolmogorov Complexity, And The Necessity Of Considering (Fuzzy) Degrees, Vladik Kreinovich, Luc Longpre, Hung T. Nguyen Aug 1998

Towards Formalization Of Feasibility, Randomness, And Commonsense Implication: Kolmogorov Complexity, And The Necessity Of Considering (Fuzzy) Degrees, Vladik Kreinovich, Luc Longpre, Hung T. Nguyen

Departmental Technical Reports (CS)

No abstract provided.


Towards Combining Fuzzy And Logic Programming Techniques, Hung T. Nguyen, Vladik Kreinovich, Daniel E. Cooke, Luqi, Olga Kosheleva Aug 1998

Towards Combining Fuzzy And Logic Programming Techniques, Hung T. Nguyen, Vladik Kreinovich, Daniel E. Cooke, Luqi, Olga Kosheleva

Departmental Technical Reports (CS)

No abstract provided.


From Semi-Heuristic Fuzzy Techniques To Optimal Fuzzy Methods: Mathematical Foundations And Applications, Vladik Kreinovich Aug 1998

From Semi-Heuristic Fuzzy Techniques To Optimal Fuzzy Methods: Mathematical Foundations And Applications, Vladik Kreinovich

Departmental Technical Reports (CS)

Fuzzy techniques have been successfully used in various application areas ranging from control to image processing to decision making. In all these applications, there is usually:

a general idea, and then

there are several possible implementations of this idea; e.g., we can use:

different membership functions,

different "and" and "or" operations,

different defuzzifications, etc.

In the first approximation, the results are usually reasonably robust and independent on this choice, so any heuristic or semi-heuristic choice works OK. However:

if we want to further improve the semi-heuristic "good enough" control or image processing techniques,

we must actually make the selection that …


Santa Clara Magazine, Volume 40 Number 2, August 1998, Santa Clara University Aug 1998

Santa Clara Magazine, Volume 40 Number 2, August 1998, Santa Clara University

Santa Clara Magazine

8 - THINKING ON THEIR FEET By Tegan McLane. A renowned choreographer coaches SCU dance students to craft bold, new expressions.

12 - MARRIED IN THE MISSION By Tegan McLane. Alumni remember returning to SCU for the most precious - and sometimes the most traumatic- days of their lives.

20 - THE GOOD DEATH By Connie Hinckley. Can physician-assisted suicide provide death with dignity as Oregon voters think?

26 - LET THEM EAT WINDOWS By Susan Vogel. An SCU symposium takes a close look at Microsoft, which grew from a little company that could to an engine geared to outdistance …


Complex Problems: Granularity Is Necessary, Granularity Helps, Oscar N. Garcia, Vladik Kreinovich, Luc Longpre, Hung T. Nguyen Aug 1998

Complex Problems: Granularity Is Necessary, Granularity Helps, Oscar N. Garcia, Vladik Kreinovich, Luc Longpre, Hung T. Nguyen

Departmental Technical Reports (CS)

No abstract provided.


Synthetic Files: Enabling Low-Latency File I/O For Qos-Adaptive Applications, Dylan Mcnamee, Dan Revel, Calton Pu, David Steere, Jonathan Walpole Aug 1998

Synthetic Files: Enabling Low-Latency File I/O For Qos-Adaptive Applications, Dylan Mcnamee, Dan Revel, Calton Pu, David Steere, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Files are a tried and true operating system abstraction. They present a simple byte-stream model of I/O that has proven intuitive for application programmers and efficient for operating system builders. However, current file systems do not provide good support for adaptive continuous media (CM) applications - an increasingly important class of applications that exhibit complex access patterns and are particularly sensitive to variations in I/O performance. To address these problems we propose synthetic files. Synthetic files are specialized views of underlying regular files, and convert complex file access patterns into simple sequential synthetic file access patterns. Synthetic file construction can …


In-Flight Fatigue Crack Monitoring Of An Aircraft Engine Cowling, Samuel Gordon Vaughn Iii Aug 1998

In-Flight Fatigue Crack Monitoring Of An Aircraft Engine Cowling, Samuel Gordon Vaughn Iii

Master's Theses - Daytona Beach

This research investigates the feasibility of implementing an in-flight fatigue crack monitoring system in an airplane to identify fatigue crack growth. An acoustic emission data acquisition system coupled with a Kohonen self organizing map neural network were used to perform the analysis.

Fatigue cracking was responsible for ripping the top of a fuselage off an Aloha Airlines Boeing 737-200 as it carried passengers over the Pacific Ocean, killing some aboard. This tragedy is perhaps a precursor of problems to come, as our nation’s aircraft age. These planes experience fatigue as they perform their daily routine of ferrying passengers from location …


Nonlinear Vibrations Of Fractionally Damped Systems, Joe Padovan, Jerzy T. Sawicki Aug 1998

Nonlinear Vibrations Of Fractionally Damped Systems, Joe Padovan, Jerzy T. Sawicki

Mechanical Engineering Faculty Publications

This paper deals with the harmonic oscillations of periodically excited nonlinear systems where hysteresis is simulated via fractional operator representations. Employing a diophantine version of the fractional operational powers, the energy constrained Lindstedt–Poincaré perturbation procedure is utilized to establish the harmonic solution. The constrained perturbation procedure was employed since it allows for the handling of strong damping and exciting forces over the full span of the driving frequency range. Based on the approach taken, the long time behavior of the fractionally damped Duffing's equation is studied in detail. Of special interest is the determination of the influence of fractional order …


Modeling Multilayered Pcb Power-Bus Designs Using An Mpie Based Circuit Extraction Technique, Hao Shi, Jun Fan, James L. Drewniak, Todd H. Hubing, Thomas Van Doren Aug 1998

Modeling Multilayered Pcb Power-Bus Designs Using An Mpie Based Circuit Extraction Technique, Hao Shi, Jun Fan, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

A circuit extraction tool (CEMPIE) has been developed based on the mixed-potential integral equation (MPIE) using a quasi-static approximation. A power-bus in a multi-layered PCB consisting of a pair of dedicated ground and power planes is studied using this tool. The distributed behavior of a power-bus is represented by a collection of passive circuit elements, which is valid up to several gigahertz. The decoupling performance of a power-bus due to its layer spacing and the dielectric constant is evaluated for simple test geometries. The impact of the relative distance between the noise source and the potential receiver is also studied. …