Digital Commons Network^™

Artificial Neural Network Based Model For Computation Of Injection Mould Complexity, Rawin Raviwongse, Venkat Allada

Engineering Management and Systems Engineering Faculty Research & Creative Works

The cost of injection mould construction depends primarily on the mould complexity. The ability to estimate the mould complexity before releasing the final drawings for construction purposes will greatly help the designers to understand the implications of their design on cost. Mould complexity depends on several factors such as part geometry, parting line, materials, and number of cavities per mould. In most industries, the mould complexity evaluation is performed manually based on past experiences of mould makers. Faced with a shortage of experienced mould makers, there is a pressing need for development of computer-aided tools for mould complexity evaluation. In …

Innovative Applications Of Groupware For Solving Engineering Design Problems, Leslie F. Monplaisir, Colin Othniel Benjamin, Choayuan Lu

Engineering Management and Systems Engineering Faculty Research & Creative Works

In these case studies, groupware was used as a group decision-making environment to assist teams evaluating a quality function deployment framework for risk management and agile manufacturing system designs. In the first case, teams identified customers' requirements and risk categories for a research and development project. They then mapped the relationship between these customer requirements and the risk categories. In the second case, cross-functional teams collaborated in selecting the best layout for a cellular manufacturing facility. These experimental findings support the use of group decision systems by design and project teams required to manage R&D projects or to design agile …

Self-Assessment Of Total Quality Management Programs, Hung Yi Wu, Henry Allen Wiebe, John Politi

Engineering Management and Systems Engineering Faculty Research & Creative Works

Total quality management (TQM) has been increasingly accepted as a management philosophy. Criteria such as those contained in the Malcolm Baldrige National Quality Award (MBNQA) often guide TQM implementation. However, reports indicate that fully assessing TQM efforts is difficult and hiring experts to help with this task is expensive. Using survey instruments is an attractive alternative to full-scale assessment. Despite the availability of many papers covering organizational performance assessment, few instruments specifically address TQM evaluation. Furthermore, none of the TQM assessment instruments has been subjected to rigorous validation; thus, only modest confidence can be placed in results obtained from their …

Hydro Unit Commitment In Hydro-Thermal Optimization, Chao-An Li, E. Hsu, Chung-Li Tseng, A. J. Svoboda, R. B. Johnson

Engineering Management and Systems Engineering Faculty Research & Creative Works

In this paper, the authors develop a model and technique for solving the combined hydro and thermal unit commitment problem, taking into full account the hydro unit dynamic constraints in achieving overall economy of power system operation. The combined hydrothermal unit commitment problem is solved by a decomposition and coordination approach. Thermal unit commitment is solved using a conventional Lagrangian relaxation technique. The hydro system is divided into watersheds, which are further broken down into reservoirs. The watersheds are optimized by network flow programming (NFP). Priority-list-based dynamic programming is used to solve the hydro unit commitment (HUC) problem at the …

A Biologically Inspired Connectionist Architecture For Directing Attention To Salient Visual Field Objects, David Lee Enke

Engineering Management and Systems Engineering Faculty Research & Creative Works

In an attempt to incorporate basic visual attention abilities into existing artificial vision systems, a neural model of the bidirectional interactions within and between the brain regions believed to be involved in human visual attention has been developed. This model currently gives an artificial vision system the ability to attend to salient, or pop-out features and objects within the vision system''s field of view. After a review of the physiology of human visual attention, a network model of the aforementioned neural interactions is presented, followed by a demonstration of its performance.

An Object-Based Evolutionary Algorithm For Solving Rectangular Piece Nesting Problems, Kanchitpol Ratanapan, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Nesting problems have been tackled by researchers using a vast number of algorithms in the past. Most of the algorithms, however, need to perform on a one-dimensional space. Therefore, the problem must be transformed into a one-dimensional space problem similar to the travelling salesman problem. Consequently, loss of solutions due to the dimensional reduction may occur. In this study, an object-based evolutionary algorithm for rectangular piece nesting problems is proposed. This methodology is created on truly two-dimensional space, allowing new mechanisms (i.e., individual representation, initialization, etc.) and new object-based genetic operators (i.e., hill-climbing, mutation, and recombination operators) to perform effectively …

Derivation Of Fuzzy Membership Functions Using One-Dimensional Self-Organizing Maps, Thomas E. Sandidge, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper discusses a system of self-organizing maps that approximate the fuzzy membership function for an arbitrary number of fuzzy classes. This is done through the ordering and clustering properties of one-dimensional self-organizing maps and iterative approximation of conditional probabilities of nodes in one map being the winner given that a node in the other map is the winner. Application of this system reduces fuzzy membership design time to that required to train the system of self-organizing maps.

Managing Cultural Differences For Engineers, Halvard E. Nystrom

Engineering Management and Systems Engineering Faculty Research & Creative Works

Understanding cultural issues, developing cross-cultural communication skills and recognizing the need to effectively apply these skills in the global arena are becoming critical success factors for an increasing number of engineers. To address these needs, an engineering management class has been developed at the University of Missouri-Rolla, USA, that uses a team project approach as the major method to achieve the learning objectives. The student teams develop training manuals for dealing with engineers from specific international cultures, based on the material learned in class as well as personal interactions with individuals of the specific ethnic background. An application of this …

Short-Term Resource Scheduling With Ramp Constraints [Power Generation Scheduling], Chung-Li Tseng, Chao-An Li, A. J. Svoboda, R. B. Johnson

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper describes a Lagrangian relaxation-based method to solve the short-term resource scheduling (STRS) problem with ramp constraints. Instead of discretizing the generation levels, the ramp rate constraints are relaxed with the system demand constraints using Lagrange multipliers. Three kinds of ramp constraints, startup, operating and shutdown ramp constraints are considered. The proposed method has been applied to solve the hydro-thermal generation scheduling problem at PG&E. An example alone with numerical results is also presented

Vehicle Performance Optimization Utilizing The Air Turbo-Ramjet Propulsion System; Methodology Development And Applications, Kirk Christensen

Doctoral Dissertations

"The ATR (Air TurboRocket) is an air breathing propulsion system in which the turbocompressor turbine is powered by a hot drive gas which is generated independently of the air flow through the compressor. The ATR has a lower specific impulse (Isp) and higher thrust compared to a similar size turbojet but a lower thrust and higher Isp compared to similar size solid rocket motor (SRM). This work defines the benefits of ATR propulsion for tactical vehicles.

ATR simulation codes were developed to support analysis of hypothetical ATR powered vehicles. Both turbojet powered and SRM powered vehicles were also evaluated against …

Immobilization Of Radioactive Materials In Iron Phosphate Glass, Melissa G. Mesko

Doctoral Dissertations

"The current study investigates the feasibility of using iron phosphate glass for the immobilization of radioactive wastes considered incompatible with borosilicate glass. Wastes may be incompatible with borosilicate glass due to high phosphorus content (Hanford tank sludges), the presence of halides (CsCl and SrF₂ capsules), or large amounts of uranium (SNF).

Between 20 and 60 wt% Hanford tank sludge was vitrified with an iron phosphate glass at ≤ 1200°C in 1 hour. The chemical durability of iron phosphate glassy wasteforms was as good as, or better than a reference borosilicate glass (10^-9 g/cm²/min) in distilled water …

Service Quality Using The Deviation-Score Approach To Fit In Contingency Theory In A U.S. Army Corps Of Engineers Setting, Donald Robert Groh

Doctoral Dissertations

"The purpose of this study is to learn how organizational work unit context, structure, and processes relate to service quality. The theoretical basis for the research is that organizational work units should be structured based on the work that they perform. If the work that a unit performs is highly variable, then the work unit should be structured in such a way as to provide flexibility, that is, few rules and procedures and highly decentralized decision making. If the work that a unit performs is not variable, then the work unit should be structured to provide a non-varying product or …

The Transport Properties Of Nanocrystalline Srce0.95yb0.05o3 Thin Films, Igor Kosacki, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The results of electrical transport measurements on nanocrystalline SrCe0.95Yb0.05O3 thin films are presented. Dense SrCe0.95Yb0.05O3 thin films with 30-70 nm grain size have been obtained using a spin-coating technique. These films exhibit about 103 higher electrical conductivity when compared with the bulk polycrystalline material. The grain size of thin films is stable to temperatures as high as 1000 °C since no grain-coarsening was observed. These unique electrical properties of nanocrystalline SrCe0.09Yb0.05O3 thin films are attributed to a dominant role of grain boundaries and/or interfaces. © 1996 American Institute of Physics.

Magnetic Dynamics In Underdoped Yba2⁢Cu3⁢O7−X: Direct Observation Of A Superconducting Gap, Pengcheng Dai, Mohana Yethiraj, Herbert A. Mook, Terrence B. Lindemer, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Polarized and unpolarized triple-axis neutron measurements were performed on an underdoped crystal of YBa₂⁢Cu_3⁢O_7−x (x = 0.4 ±0.02, T_c = 62.7⁢K). Our results indicate, contrary to earlier evidence, that the spin excitations in the superconducting state are essentially the same as those in the fully doped material except that the unusual 41 meV resonance is observed at 34.8 meV. The normal state spin excitations are characterized by a weakly energy-dependent continuum whose temperature dependence shows the clear signature of a superconducting gap at T_c. The enhancement at the resonance is accompanied by …

Low Temperature Hydrothermal Synthesis Of Nanophase Batio3 And Bafe12019 Powders, Fatih Dogan, Shawn O'Rourke, Mao-Xu Qian, Mehmet Sarikaya

Materials Science and Engineering Faculty Research & Creative Works

Nanocrystalline powders with an average particle size of 50 nm have been synthesized in two materials systems under hydrothermal conditions below 100°C. Processing variables, such as temperature, concentration and molar ratio of reactants and reaction time were optimized to obtain particles of reduced size and stoichiometric compositions. Hydrothermal reaction takes place between Ba (OH)₂ solution and titanium/iron precursors in sealed polyethylene bottles in the BaTiO₃ and BaFe12019 systems, respectively. While crystalline BaTiO₃ forms relatively fast within a few hours, formation of fully crystalline and stoichiometric BaFe12019 require considerably longer reaction times up to several weeks and strongly …

The Missouri Miner, December 11, 1996

The Missouri Miner Newspaper

No abstract provided.

Semiquantal Modeling Of Thermal Vibrational Relaxation Of Diatomic Molecules, Ronald James Bieniek, Steven J. Lipson

Physics Faculty Research & Creative Works

Vibrationally excited molecules play an important role in the spectroscopy, energetics, and chemical behavior of a wide range of gaseous systems of scientific and applied interest. Unfortunately, many desired collisional relaxation rates have not yet been experimentally measured, and current theoretical methods are often inadequate or too cumbersome for practical application. We report a semiquantal two-parameter scaling method for predicting relaxation rates that is very simple to employ, and impressively fits the temperature and vibrational dependencies of quantum mechanical and experimental collisional relaxation rates for several diatomic molecules (e.g., N2, HF, OH, NO) over many orders of magnitude.

The Missouri Miner, December 04, 1996

The Missouri Miner Newspaper

No abstract provided.

Automated State Model Generation Algorithm For Power Circuits And Systems, O. Wasynczuk, Scott D. Sudhoff

Electrical and Computer Engineering Faculty Research & Creative Works

A new approach of automatically generating state-space models of power circuits and systems is presented. In this approach, the composite system state equations are established algorithmically given the standard node incidence matrix and elementary branch data (e.g. resistances, inductances, back emf's). The resulting state equations can be solved using a variety of numerical techniques or commercially available computer simulation programs. An example system consisting of a three-phase generator and rectifier load is used to illustrate this approach. Experimental verification is also provided. © 1996 IEEE.

A State Space Modeling And Control Method For Multivariable Smart Structural Systems, Robert Butler, Vittal S. Rao

Electrical and Computer Engineering Faculty Research & Creative Works

A system identification technique for the derivation of minimal, continuous time state variable models for multivariable smart structural systems is presented. The structural identification technique is based on the measurement of eigenvalues and eigenvectors of the structure. Two sensors are required for each mode included in the structural system model. Unlike computational system identification techniques, the relatively large number of sensors simplifies the identification process making it ideal for systems with several inputs and outputs. Additionally, the identification technique allows the implementation of multi-input multi-output full state feedback controllers with simple analog hardware. The amount of hardware required for the …

A Voltage Control Strategy For Current-Regulated Pwm Inverters, Oleg Wasynczuk, Scott D. Sudhoff, Tin D. Tran, David H. Clayton, Henry J. Hegner

Electrical and Computer Engineering Faculty Research & Creative Works

Alternative voltage control strategies for current-regulated PWM inverters are analyzed, including previously established feedforward and feedforward/feedback controllers and a newly proposed decoupling feedback control strategy. The steady-state and dynamic characteristics of each of these control methods are illustrated and compared for a selected inverter design. It is shown that the feedforward controller exhibits steady-state error and an undesirable overshoot of the output voltages during startup. The addition of a feedback loop eliminates the steady-state error and reduces the overshoot; however, the natural response is underdamped regardless of the choice of feedback gains. A decoupling feedback control strategy that eliminates the …

Efficient Parallel Algorithms On Reconfigurable Mesh Architectures, His-Chieh Lee, Fikret Ercal

Computer Science Technical Reports

This dissertation describes a number of novel parallel algorithms for solving maze-routing problems and string matching problems on a proposed reconfigurable mesh architecture.

Section I reviews the field of reconfigurable parallel computing. This includes an introduction to a number of reconfigurable architectures proposed in the literature and a list of references to the current literature on algorithms in the field of reconfigurable computing.

Section II presents a number of time-efficient algorithms to solve the mazerouting problem. Maze-routing algorithms are used in VLSI routing and robot path planning. In that section, definitions for absolute shortest path (ASP), shortest duplex-path (SDP), shortest …

Parallel Fast Multipole Algorithms For N-Body Simulations, Jui-Lin Lu, Daniel Okunbor

Computer Science Technical Reports

The computer simulation of N-Body problems has a wide range of applications. It is known that simulations can take years to complete. This can be greatly improved by using efficient algorithms in force calculations and in applying the computing power of parallel computers to the problem. A tremendous amount of work has been devoted to parallelization of the fast multipole algorithm (FMA) which is one of the fastest algorithms in force calculations. However, most parallel implementations target a specific machine. We developed an efficient communication scheme for parallel FMA in a message passing environment and implemented it by using Message …

Angle-Resolved X-Ray Circular And Magnetic Circular Dichroisms: Definitions And Applications, Sy Y. Tong, X. Q. Guo, James G. Tobin, George Daniel Waddill

Physics Faculty Research & Creative Works

We introduce definitions of angle-resolved x-ray circular dichroism (ARXCD) and magnetic x-ray circular dichroism (ARMXCD). As defined, the much larger effect of circular dichroism (ARXCD) is separated from the smaller magnetic (ARMXCD) effect. In all materials, ARXCD is zero along mirror planes while nonzero elsewhere. ARMXCD is nonzero only in magnetic materials. The measurement and analysis of ARMXCD allow element specific surface magnetism and surface structure as well as their inter-relationship to be studied as functions of the outgoing electron's direction.

A Multimedia Manual On The World Wide Web For Telecommunications Equipment, Andrew L. Sears, Steve E. Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

An interactive multimedia educational manual on the Internet through the World Wide Web for commercial optical fiber telecommunications equipment is described. The Telecommunications Laboratory Manual is a vehicle for enhancing engineering education with realistic laboratory or virtual laboratory experience. The manual provides a brief system tutorial, operating instructions, on-line help, and multimedia experimental demonstrations. It incorporates block diagrams, photographic images, and hypertext links that are mouse clickable, allowing users to access documents or links describing components or processes in any order. An experimental section guides students through laboratory experiences, demonstrates selected equipment characteristics, and provides for direct instructor contact through …

Elucidation Of Vancomycin's Enantioselective Binding Site Using Its Copper Complex, Usha B. Nair, Samuel S.C. Chang, Daniel W. Armstrong, Yasir Y. Rawjee, Drake S. Eggleston, James V. Mcardle

Chemistry Faculty Research & Creative Works

Vancomycin forms a stable complex with Cu2+ in neutral aqueous solutions. The enantioselectivity of native vancomycin was compared to that of the copper-vancomycin complex using capillary electrophoresis (CE). There were significant differences in their enantioselectivities. This can be attributed to the fact that copper ion coordinates with some of the same functional groups in vancomycin that are essential for chiral recognition and enantioresolution. An amine moiety that provides one of the more important enantioselective interactions was identified. This chiral interaction site was illustrated using a color-coded, space-filling model of the X-ray crystal structure of the copper-vancomycin complex. Successful enantioselective interactions …

Magnetic Dynamics In Underdoped Yba2cu3o72x: Direct Observation Of A Superconducting Gap, Pengcheng Dai, Mehmet Yethiraj, Herbert A. Mook, T. B. Lindemer, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Polarized and unpolarized triple-axis neutron measurements were performed on an underdoped crystal of YBa₂Cu₃O_7-x (x 0.4 6 0.02, T_c 62.7 K). Our results indicate, contrary to earlier evidence, that the spin excitations in the superconducting state are essentially the same as those in the fully doped material except that the unusual 41 meV resonance is observed at 34.8 meV. The normal state spin excitations are characterized by a weakly energy-dependent continuum whose temperature dependence shows the clear signature of a superconducting gap at T_c. The enhancement at the resonance is accompanied by …

The Missouri Miner, November 20, 1996

The Missouri Miner Newspaper

No abstract provided.

Dynamics Of An Adsorbed Patch And A Model For Spreading Of Films Of Ultralow Thicknesses, Partho Neogi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamics of ultrathin films of liquids with vanishing 3D volatility, on solid surfaces, has been modeled by assuming that the films can be taken to be adsorbed patches spreading under surface diffusion. when the phase behavior of the adsorbed films is taken into account, it is seen that a vapor patch will spread without limits and evolve into a Gaussian profile. For a liquid film which has low 2D volatility, a patch will appear to equilibrate and the surface ahead will remain dry. This is the "pancake," a case where a wetting liquid stops spreading. the spreading kinetics is …

The Missouri Miner, November 13, 1996

The Missouri Miner Newspaper

No abstract provided.