Engineering Commons^™

Dual Versus Single Spark Plug: A Critique, I Mshoro

Tanzania Journal of Engineering and Technology (TJET)

Dual spark plugs are occasionally employed on certain modern Spark lg- nited (S') engines, viz lean burn engines. Their benefit has generally been noticed in the operating conditions whenfuel-air mixture is very lean, or when a larger proportion of EGR has been employed, or during the part load conditions and so on. An extensive literature survey has indi- cared an interesting spectrum of reasons for gains due to the dual spark plug. A consistent explanation is found to be missing which can describe the behaviour of the engines with single versus dual spark plugs There are quite "few researchers who …

Suitability Of The Present Strategic Information Technology Planning (Sitp) Methodologies To The Developing Countries, A Victor

Tanzania Journal of Engineering and Technology (TJET)

The needfor strategy formulation, or in general terms strategic planning, for IT is considered as one of the most important aspects of IT manage- ment. To this end, there are a number of IT strategy formulation method- ologies world-wide. These methodologies were developed over a span of time, starting from mid 1960's when IT use started to become a serious issue in the developed countries, and continued with the trends in IT de- velopment and use, as was applicable in those countries. Morc recent of the methodologies were developed through improvements on earlier ones, and based on the new challenges …

A Preliminary Model For Lot Sizing In Semiconductor Manufacturing, Tali F. Carmon, Steven Nahmias

Industrial and Manufacturing Engineering

No abstract provided.

Acuta Enews June 1994, Vol. 23, No. 6

ACUTA Newsletters

In This Issue

Board report

President's message

White papers/blue papers

TFS takes aim at toll fraud

ITFS Monograph review

Lost on the Information Highway?

Dynamic Load Balancing For A Parallel Discrete-Event Battlefield Simulation, Seth R. Guanu

Theses and Dissertations

This thesis investigates issues involved in developing a dynamic load balancing model for a parallel discrete event battlefield simulation. The research covers issues in task management, discrete-event simulation, parallel simulation, and load balancing. There are four primary issues discussed concerning the design of a dynamic load balancing model. The first issue is processor load evaluation which deals with the calculation of the amount of work on a processor. The second issue is load balancing profitability determination which deals with the decision to load balance or not based on some cost-gain relationship. The third issue is task migration which deals with …

An Empirical Investigation Of Total Quality Management (Tqm) Effectiveness In Healthcare Organizations, Lokesh S. Basappa

Masters Theses

American hospitals are implementing quality programs to offer higher quality service at reduced cost. However, the results of these programs in many hospitals have often not met expectations.

This research analyzed the effectiveness of Total Quality Management (TQM). The objective of the study was to better understand how TQM strategies can best be applied by hospitals. An empirical survey was distributed to Michigan hospitals and an analysis was performed to meet this objective.

The survey results show that hospitals involved indirectly with quality programs haven't realized that they are implementing TQM strategies. On the other hand some hospitals say that …

Embedded Chaotic Time Series: Applications In Prediction And Spatio-Temporal Classification, James R. Stright

Theses and Dissertations

The Deterministic Versus Stochastic algorithm developed by Martin Casdagli is modified to produce two new, methodologies, each of which selectively uses embedding space nearest neighbors. Neighbors which are considered prediction relevant are retained for local linear prediction, while those which are considered likely to represent noise are ignored. For many time series, it is shown possible to improve on local linear prediction with both of the new algorithms. Furthermore, the theory of embedology is applied to determine a length of test sequence sufficient for accurate classification of moving objects. Sequentially recorded feature vectors of a moving object form a training …

Work Measurement Decision Diagram Development And Application At Nasa's Kennedy Space Center, Susan L. Murray, Amanda M. Mitskevich, Joseph J. Pignatiello Jr., Timothy S. Barth, William W. Swart

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper presents a decision flow diagram developed at NASA's Kennedy Space Center for the selection of the appropriate work measurement methodologies for Space Shuttle processing.

Acuta Enews May 1994, Vol. 23, No. 5

ACUTA Newsletters

In This Issue

Board Report

President's message

VTEL goes to Russia

Video at Univ. of Missouri

DC at a glance

Takin' care of business

Acuta Enews April 1994, Vol. 23, No. 4

ACUTA Newsletters

In This Issue

Board report

President's message

ISDN at WVU

Book reviews

Hold down toll fraud

Takin' care of business

An Ergonomics Approach To Evaluate The Use Of Two Different Fixtures For Upholstering, Maria Luisa Roa

Masters Theses

A furniture company in West Michigan proposed an evaluation of a new fixture that will be used in a repetitive manual stapling operation.

Numerous studies reveal that activities involving repetitive wrist motions cause inflammation in the median nerve that runs through the structure of the carpal wrist, causing a cumulative disorder known as Carpal Tunnel Syndrome (CTS). This syndrome is one of the most prevalent in industrial settings and service companies.

This study investigated if the use of a new design of a fixture had an impact on operators' performances. Three-dimensional comparative analysis was used to observe operators' wrist angular …

Acuta Enews March 1994, Vol. 23, No. 3

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In This Issue

Board reprt

President's message

Baltimore update

Improvements at the University of Chicago

21st Century technology

Resource Library is growing

Application Of Sequential Quadratic Programming To Large-Scale Structural Design Problems, Mark A. Abramson

Theses and Dissertations

Large-scale structural optimization problems are often difficult to solve with reasonable efficiency and accuracy. Such problems are often characterized by constraint functions which are not explicitly defined. Constraint and gradient functions are usually expensive to evaluate. An optimization approach which uses the NLPQL sequential quadratic programming algorithm of Schittkowski, integrated with the Automated Structural Optimization System ASTROS is tested. The traditional solution approach involves the formulation and solution of an explicitly defined approximate problem during each iteration. This approach is replaced by a simpler approach in which the approximate problem is eliminated. In the simpler approach, each finite element analysis …

A Simulation Approach To Granite Sentry System Analysis, Marilyn J. Bauer

Theses and Dissertations

This study demonstrated the use of simulation modelling to analyze Granite Sentry system performance. The availability simulation model constructed provides a number of system performance measures as a function of component MTBFs and MTTRs. Analysis of failure data prior to model construction supported the generally accepted use of exponentially distributed failure rates and lognormally distributed repair times.

The Effective Use Of Animation In Simulation Model Validation, Christopher L. Swider

Theses and Dissertations

This study examined two animation displays moving icons, bar graphs at two presentation speeds to determine how each of these factors affected the animations ability to communicate violations of model assumptions. Subjects viewed animation displays individually and in combination at each presentation speed. Eight problem scenarios were presented to evaluate each animations ability to communicate violations of different assumptions. Each animations communication ability was measured subjectively and objectively. Subjective measures in the form of pairwise comparisons were used to calculate normalized preference ratings for each animation. objective measures included problem identification accuracy and problem time. Subjective results indicated that moving …

Proactive Monitoring Of Performance In Stochastic Communication Networks, John C. C. Van Hove

Theses and Dissertations

This research proposes several models for placing bounds on the expected values of some dynamic performance measures for computer communication networks with failing components. These models provide an understanding of expected network performance that is useful in the process of proactive performance monitoring and also in defining level of service agreements with network users. There were three objectives for this research. The first objective was to extend some existing models of steady-state stochastic network performance to a dynamic network flow representation in order to capture the dynamic nature of proactive monitoring. The second objective was to convert the extended absolute …

Assessing The Vulnerability Of Multi-Commodity Networks With Failing Components, Alan R. Robinson

Theses and Dissertations

This research proposes an analytical approach for assessing flow disturbance, or compromise, based on limited sampling of arc flow information in multi-commodity, or multiple origin-destination O-D, networks with failing arcs. There were three objectives established for this research. The first objective was to bound the expected flow, given the arcs fail with certain probabilities, which was accomplished by reviewing current approaches for single-commodity networks and extending the results to the multi-commodity case. The second objective was to determine the best placement of flow monitors to obtain the most accurate estimates of O-D pair volumes. This was accomplished using a multi-criteria …

An Rsm Study Of The Effects Of Simulation Work And Metamodel Specification On The Statistical Quality Of Metamodel Estimates, Michael K. Taylor

Theses and Dissertations

This research investigated the combined influence of simulation work and metamodel specification on the statistical quality of the estimates obtained from the resulting metamodels of the simulation data. A 9 x 2 x 2 experiment consisting of 9 cases of simulation work, 2 levels of metamodel specification, and 2 levels of design fractionation were designed for 8 different configurations of MMk queues. The only observed statistic for this experiment was the average queue length. Simulation estimates for each configurations average queue length were calculated directly from the simulation data. In addition, the metamodels were fit to the simulation data and …

A Mean Value Analysis Heuristic For Analysis Of Aircraft Sortie Generation, Richard C. Jenkins

Theses and Dissertations

The primary objective of this study was to develop an analytical methodology based on the Mean Value Analysis algorithm that approximates the performance characteristics of a queueing network model QNM containing a fork- join queue with probabilistic branching. These performance characteristics are response time, throughput and queue length at each station. The QNM solved contains the essential features of the aircraft sortie generation process. The sensitivity of the methods accuracy to increases in server utilization was determined. The comparisons of the results of the MVA heuristic to the outputs of the Logistics Composite Model LCOM simulation indicate that the heuristics …

A Fortran Based Learning System Using Multilayer Back-Propagation Neural Network Techniques, Gregory L. Reinhart

Theses and Dissertations

An interactive computer system which allows the researcher to build an optimal neural network structure quickly, is developed and validated. This system assumes a single hidden layer perceptron structure and uses the back- propagation training technique. The software enables the researcher to quickly define a neural network structure, train the neural network, interrupt training at any point to analyze the status of the current network, re-start training at the interrupted point if desired, and analyze the final network using two- dimensional graphs, three-dimensional graphs, confusion matrices and saliency metrics. A technique for training, testing, and validating various network structures and …

Analysis Of Thunder Combat Simulation Model, Timothy S. Webb

Theses and Dissertations

TAC THUNDER, or THUNDER, is a two-sided large scale computer simulation model that simulates air and ground combat, logistics, and limited airlift at the theater level. It is in use by several allied nations, major defense contractors, and various Department of Defense DoD analysis agencies. The objectives of this thesis effort were to examine the overall model variability, examine the model output for possible interrelationships, and examine the model sensitivity to input parameters. A univariate and multivariate analysis was performed to examine the first two objectives. The univariate analysis consisted of an analysis of the confidence intervals and replication requirements …

An Integer Solution Heuristic For The Arsenal Exchange Model (Aem), Daniel J. Green

Theses and Dissertations

The Air Force Studies and Analyses Agency sought a method for converting the continuous solution produced by the Arsenal Exchange Model into a feasible integer solution. The current integerization method leaves weapons unused and targets uncovered and could be improved. In the method developed, the noninteger valued variables in the continuous solution are rounded down to the nearest integer to produce a truncated solution. An integer goal program is then used to reallocate the weapons and targets made available in the rounding process. The truncated solution is then combined with the solution of the integer goal program to produce a …

An Air Mission Planning Algorithm For A Theater Level Combat Model, Brian J. Griggs

Theses and Dissertations

This thesis describes the development of an air mission planning algorithm for the Joint Staffs Future Theater Level Model FTLM. The overall problem scope was to develop an algorithm to handle major factors bearing on the combat mission planning problem while providing hook-ups for the FTLM architecture. Other aspects of the problem included finding the appropriate level of detail, developing a fast solving technique, and attempting to use existing data. The problem was handled by using some ideas from existing aircraft allocation algorithms and by adding some new techniques. The proposed air mission planning algorithm supplies the optimum degree of …

An Analysis Of Stopping Criteria In Artificial Neural Networks, Bruce Kostal

Theses and Dissertations

The goal of this study was to decide when to terminate training of an artificial neural network ANN. In pursuit of this goal, several characteristics of the ANN were monitored throughout ANN training classification error rate of the training set, testing set, or a weighted average of the two moving average classification error rate measurements of the difference between ANN output and desired output error sum of squares, total absolute error. or largest absolute error or ANN weight changes absolute weight change, squared weight change, or relative weight change. Throughout this research, the learning rate was held constant at 0.35. …

An Investigation Of Simulated Annealing Applied To Structural Optimization Problems, Richard C. Mceachin

Theses and Dissertations

This thesis investigates the feasibility of using Simulated Annealing SA in structural optimization problems. The investigation involves solving benchmark structural optimization problems with an SA algorithm, and comparing its solutions to those found by four other optimizers. Overall, the analysis shows that SA has limited applicability in structural optimization. Two primary factors were found to adversely impact the performance of the SA algorithm in these problems. These factors are high dimensionality, and high levels of constraint. The difficulty involved in solving these problems with a random search increases exponentially with the number of dimensions. The number, and non-linearity, of the …

An Analysis Of Air Force Acquisition Engineering Officer's Perceptions Of The Adequacy Of Their Preparation For Management, Steven E. Woodruff

Theses and Dissertations

The purpose of this study was to determine how much time Air Force acquisition engineers spend in performing management functions, how those engineers spend in performing management functions, how those engineers perceive their management training, and which types of training contribute the most to managerial competency. The results from surveys of 215 acquisition engineers assigned to ASCEN, Wright-Patterson AFB, OH and their supervisors revealed that engineers do indeed spend substantial amounts of time performing management functions. Slightly more than half the engineers reported spending at least 50 of an average workday performing management functions. Over 53 of engineers responding to …

Acuta Enews February 1994, Vol. 23, No. 2

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In This Issue

Board report

Presidents message

What's right...what's wrong? States to develop telecommunications modernization plans

21st century technology

A Finite Capacity Queue With Markovian Arrivals And Two Servers With Group Services, Srinivas Chakravarthy, Attahiru S. Alfa

Industrial & Manufacturing Engineering Publications

In this paper we consider a finite capacity queuing system in which arrivals are governed by a Markovian arrival process. The system is attended by two exponential servers, who offer services in groups of varying sizes. The service rates may depend on the number of customers in service. Using Markov theory, we study this finite capacity queuing model in detail by obtaining numerically stable expressions for (a) the steady-state queue length densities at arrivals and at arbitrary time points; (b) the Laplace-Stieltjes transform of the stationary waiting time distribution of an admitted customer at points of arrivals. The stationary waiting …

Capacity Of Automated Highway Systems: Effect Of Platooning And Barriers, H.-S. Jacob Tsao, Randolph Hall, Bruce Hongola

Faculty Publications

The concept of Automated Highway Systems (AHS) is based on the belief that an appropriate integration of control and communication technologies placed on the vehicle and on the highway can lead to a large improvement in capacity and safety without requiring a significant amount of additional highway right-of-way. Stemming from this belief are various conceptual scenarios for vehicle/highway automation.An AHS consists of two major components: vehicle/highway automation technology and highway operating strategy. In this paper, we study the capacity of key AHS operating scenarios.

Acuta Enews January 1994, Vol. 23, No. 1

ACUTA Newsletters

In This Issue

Board Report

Presidents message

FCC proposes regulations for toll fraud

Cruising he information superhighway

21st century technology