Digital Commons Network^™

Dynamic Performance-Based Student Model For An Intelligent Simulation Training System, Jenifer M. Sargeant

Retrospective Theses and Dissertations

Student modeling has been the subject of research since the mid-1970's. A student model is an evolving description of what the student knows about the subject domain. Much of the previous research has concentrated on evaluating a student in performing cognitive tasks. The Intelligent Simulation Training System (ISTS) applies the techniques of Artificial Intelligence, Intelligent Tutoring Systems and Expert Systems to simulation-based training. The ISTS Student Model is unique in that it evaluates the student in performance-based tasks. It monitors and records the student's ability to maintain relationships between objects in space and time. The scope of this research was …

Efficient Algorithms For The Fixed Charge Problem, Ahmad Abdulah Moreb

Retrospective Theses and Dissertations

The main thrust of this research is to develop four solution procedures for the Fixed Charge Problem. All are based on approximating the fixed charge component by strictly polygonal linear components. The first procedure uses the functions technique to approximate the fixed charge; then linear programming with the restricted-basisentry technique is used to arrive at the final solution. Although this method starts with an approximated version of the fixed charge component, it arrives at an exact value to the objective function without the need for re-evaluating the objective function. The other three solution procedures are based on approximating the fixed …

A Comparison Of Two Microcomputer Continuous Simulation Languages, Amy Brannon Kirkland

Retrospective Theses and Dissertations

Until the early 1980s, most digital simulation models of reasonably complex systems required the use of a mainframe for a solution to be obtained in a timely manner. Recently, the declining prices of computer memory, operating systems, and modern hardware have supported the implementation of large simulation packages on smaller machines. Today, tremendous improvements in the performance of microcomputers have provided the simulationist with a completely personalized, less expensive computing environment. Operating within a microcomputer environment, the simulationist must choose a suitable computer language. Often, user familiarity dictates the selection of a language, while other factors such as ease of …

The Feasibility Analysis Of Cooling A Residential Space Using An Underground Air Pipe Coupled With An Air Chimney, Nam Ky Trinh

Retrospective Theses and Dissertations

This study examines the thermal and economic feasibility of using an earth-cooled air system of residential space cooling. A residential building located in Orlando, Florida was modeled to determine the sensible cooling load for various design factors. A parametric study was conducted to determine the effects of the following: inside set temperature, infiltration rate, and overall heat transfer coefficient of the walls and roof. The inside set temperature had the greatest impact on the cooling energy load, followed by the infiltration rate and the overall heat transfer coefficient of the walls and roof.

Two load conditions were examined to determine …

High Resolution Monopulse Tracking, Larry Alan Young

Retrospective Theses and Dissertations

High Resolution Radar techniques are applied to the problem of resolving a multiple target array and locating its geometric center without the usual biasing toward the brightest targets. Monopulse radar techniques are combined with high resolution stepped frequency pulse train signal processing in an amplitude tracking radar.

A single pulse monopulse system's aimpoint is biased toward the brightest point targets in an array. However, by using a stepped frequency pulse monopulse radar, the cross range distance to each individual scattered may be found.

Unlike the single pulse monopulse system, the aimpoint is independent of the reflectivity of the targets. The …

Economic Design Of Lot-By-Lot Acceptance Sampling By Attributes, Michael S. Wall

Retrospective Theses and Dissertations

Risk-based sampling plans have long been the accepted standards in the practice of acceptance sampling for quality control. Usually the economic consequences of a given sampling plan are assessed by experience and intuition at best. With the availability of high speed computers and well-proven statistical methods, economically-optimal sampling pl a ns can now be developed so that much of the guesswork is removed. This study first surveys these methods for deriving economically-optimal sampling plans. Then, recognizing the reluctance in government and industry to abandoning ris k-based design of sampling plans, a method is explored which poses a compromise between the …

Numerical Analysis Of The Resonant States Of Quantum Wells And Superlattice Devices, Alan Gilbert Whittaker

Retrospective Theses and Dissertations

This thesis is concerned with the development of a numerical model to describe the resonant states associated with quantum well and superlattice devices. A numerical method is described where the time-independent Schrodinger equation is represented as a series of simultaneous algebraic equations using the finite-element method. The eigenvalues for these equations are then found using a Sturm sequence, and the eigenfunctions subsequently calculated using a reverse iteration method containing orthogonality constraints. Simulations of specific devices are presented and compared with experimental results and good correlation is observed.

Finite Element Analysis Of A Glass Fiber Inclusion, Jeffery R. Southland

Retrospective Theses and Dissertations

This analysis investigates the micromechanical behavior of a fiber-reinforced composite. Two realistic deviations from the typical set of simplifying assumptions are considered: nonhomogeneous matrix properties and imperfect fiber/matrix bonds. The stress effects due to a soft matrix interlayer at the fiber interface and the loss of a portion of the fiber/matrix interface bond are examined. The analysis is performed with the ANSYS finite element program. The effects of higher order shape functions and different mesh densities are studied. The final results are compared to a previous analysis performed at Florida Technological University (now University of Central Florida) which utilized a …

Analysis Of Phase Noise In Phase Lock Loop, Diane Marie Pavik

Retrospective Theses and Dissertations

This research report presents an introduction into phase lock loops (PLL) with a major emphasis on calculating phase noise in frequency synthesizers. A PLL model that incorporates the major sources of noise is presented for the purpose of design analysis. The model can be used to analyze second and fifth order PLLs which allows the accurate calculation of phase noise as a function of independent variable design parameters. The stability of PLLs is also analyzed to show the effects of a marginally stable system on the resultant phase noise. Developing an accurate PLL model which accounts for the major sources …

Axisymmetric Wave Propagation In A Finite Linear Elastic Cylinder, Brian D. Johnson

Retrospective Theses and Dissertations

This work addresses the linear elastic analysis of axisymmetric wave propagation in a finite elastic cylinder. The waves are generated by the Fast Triaxial Device (FTRXD), which fails soil specimens at very rapid rates. The very short duration of the triaxial tests requires the consideration of wave phenomena in the analysis of the test results.

The soil specimens are modeled as linear elastic cylinders which are compressed in the axial direction. The resulting axisymmetric waves are analyzed with the wave equations which are cast in finite difference form, allowing the solution of displacements and stresses throughout the cylinder as a …

Continuous Time Convolution Model For Generation Synthetic Hydrographs, Cheryl Brooks

Retrospective Theses and Dissertations

Synthetic hydrographs are often used in stormwater management to provide estimates of peak rate, volume and time distribution of stormwater runoff. A hydrograph model based on the mathematical technique of convolution was developed using an exponential routing response function and the basic watershed continuity equation. After incorporating the model into a computer program, it was calibrated using hydrographs from four urban and three rural watersheds. The watersheds are located in regions of west and south Florida and range in size from 14.7 to 3500 acres. Two other hydrograph models, the Soil Conservation Service's Unit Hydrograph (SCS-UH) mode 1 and the …

Part-Time Mba, Rollins College

Text Materials of Central Florida

Rollins College catalogue with list of faculty and students and courses by department.

Applications Of Lattice Filters To Quadrature Mirror Filter Banks, Gregory R. Jaspers

Retrospective Theses and Dissertations

Presented is a method for designing and implementing lattice filters to be used in Quadrature Mirror Filter (QMF) Banks. Quadrature Mirror Filter Banks find use in applications where a signal must be spilt into subbands operated on then reconstructed in the output. Because of their structure, lattice filters do this very well and allow perfect reconstruction, even when the lattice coefficients must be quantized. In this paper QMF's and Lattice Filters are derived and analyzed. Application of the lattice filter is presented along with a design program and example of its use to implement a QMF. The computer aided design …

Learning Curve Model For Interrupted Production, Behzad Zarkoob

Retrospective Theses and Dissertations

Traditionally the learning curve technique has been applied to the case of continuous production. In such cases the cost par unit declines by a constant or staged percentage due to the learning phenomenon. Although this technique has been an important management tool to predict cost and productivity, there are other factors that wil~ affect the learning curves and its forecasts. One of these factors is "forgetfulness," which is caused by program interruptions for a significant period of time. It is expected that due to the interruption a relearning process may have to take place. The objective of this report is …

Lansim: A Simulation Package For Estimating Performance Characteristics Of A Class Of Local Area Networks, Gregory Charles Buchner

Retrospective Theses and Dissertations

ABSTRACT During recent years, the trends in computer resource organization have seen the replacement of the traditional mainframe computers and their timesharing terminals with individual desktop workstations. These workstations can offer more computational power than the mainframes of less than a decade ago. With this distribution of processing from the more traditional mainframe computer comes the need to share peripheral resources among these desktop workstations. These include items such as file systems, tape drives, printers, plotters, and graphics display devices. A common way to share these among the multi-computer environment is to provide a transparent gateway that allows each workstation …

Rollins College Brevard Campus, Rollins College

Text Materials of Central Florida

Rollins College catalogue with list of faculty and students and courses by department.

Rollins College Catalogue, 1988-1989, Rollins College

Text Materials of Central Florida

Rollins College catalogue 1988-1989 with list of faculty and students and courses by department.

Pathological Gambling: A Comprehensive Review, Victoria L. Crowder

Retrospective Theses and Dissertations

No abstract provided.

The Feasibility Of Computerized Cognitive Testing As A Surrogate Measure For Assessment Center Performance, Leilani M. De Saram

Retrospective Theses and Dissertations

The use of microcomputerized cognitive testing of personnel has thus far been limited to military and environmental stressor applications. The investigation of such testing as a substitute for assessment center performance represents a novel application of this technology. An examination of the relationship between performance on a cognitive test battery and assessment center performance was conducted.

A battery of selected microcomputerized tests measuring cognitive constructs was administered to assessment center candidates in law enforcement occupations. Contrary to expectations, the computerized cognitive measurements did not exhibit significant correlations with assessment center performance measures. It was speculated that the two measures assessed …

New Synthetic Transformations Of 1-Benzyl, 3,5-Dibromo, 1h-1,2,4-Triazole /C, Adam Michael Fivush

Retrospective Theses and Dissertations

This report details the study of the nucleophilic substitution of 1-benzyl-3,5-dibromo-lH-1,2,4-triazole. A variety of nucleophiles have been studied to date. The nucleophiles studied primarily fall into the categories of Phosphorous, Oxygen and Sul fur species. Some of the initially formed substitution products are thermally unstable and undergo unique rearrangements. The report describes the physical properties, 1H NMR, 13c NMR, IR and Mass spectra for all of the synthesized compounds. Possible mechanistic pathways are presented for the formation of the prepared compounds. Recommendations are made in order to suggest future research opportunities in this area.

Unexpected Products From The Reactions Of 1-(Bromodifluoromethyl)-2-(Bromoalkanes With Potassium Hydroxide,Characterization Of Some Gen-Difluorodienes And Attempted Syntheses Of Gem-Difluorocyclopropanes, Mariana Michael

Retrospective Theses and Dissertations

This research report discusses the reactions of CF2Br2 with various alkenes. Attempts to synthesize some gemdifluorocyclopropanes from alkenes and CF2x2 (X=Br, I) by modified Simmons-Smith procedures were Dehydrohalogenation reactions of some not successful. 1,3-dibromo-1,1- difluoroalkanes were conducted with potassium hydroxide or tributylamine. Heating cis or trans 1-(bromodifluoromethyl)- 2-bromocyclohexane with potassium hydroxide does not produce the expected gem-difluorodienes but instead gives the corresponding a,$ -unsaturated carboxylic acid. The mechanism for the productions of the various reaction intermediates from the reaction of the cyclic dibromide with potassium hydoxide is proposed. Experimental evidence supporting the proposed mechanism is presented. Gemdifluorodienes are isolated when …

Laser Induced Darkening Semiconductor Dope Glasses, Jayant Malhotra

Retrospective Theses and Dissertations

No abstract provided.

Development Of Techniques To Perform Simulation-Adaptation In A Simulation Training Environment Using Expert System Methods, Cheryl E. Bagshaw

Retrospective Theses and Dissertations

The use of computers for instructional purposes is steadily increasing, along with an emphasis on developing systems which create environments tailored to human beings. Artificial Intelligence techniques have been incorporated into these systems with an aim at developing better methods of modeling of simulating knowledge and intelligent behavior. One type of these systems, Intelligent Simulation Training Systems (ISTS), utilize a simulation in the training process. This is an ideal environment for the instruction of skills which focus on the ability to understand the time and space relationships of objects.

An intelligent tutor module of an ISTS must configure scenarios for …

A Coprocessor Design For The Architectural Support Of Non-Numeric Operations, Timothy W. Curry

Retrospective Theses and Dissertations

Computer Science is concerned with the electronic manipulation of information. Continually increasing amounts of computer time are being expended on information that is not numeric. This is represented in part by modem computing requirements such as the block moves associated with context switching and virtual memory management, peripheral device communication, compilers, editors, word processors, databases, and text retrieval. This dissertation examines the traditional support of non-numeric information from a software, firmware, and hardware perspective and presents a coprocessor design to improve the performance of a set of non-numeric operations. Simple micro-coding of operations can provide a degree of performance improvement …

A Student Performance Evaluation Method For An Intelligent Simulation-Based Tutoring System, Camille Marie Dixon

Retrospective Theses and Dissertations

Intelligent simulation-based tutoring systems (ISTS) present intriguing and complex environments for the training of high performance skills. These skills involve the manipulation of objects within time and space constraints.

As with any tutoring system, there must exist a performance measurement methodology. Within an ISTS there is a module which functions as a tutor and a module which functions as a student modeler. These fundamental modules are required to make effective individualized tutoring decisions. However, each of these modules rely on information from a performance measurement system or evaluation system.

The objective of this research was to establish a performance evaluation …

Optimization Of Storm Sewer Construction Costs Using A Microcomputer Program, Dawn E. Fetter

Retrospective Theses and Dissertations

When designing a storm sewer system there is a material and labor cost trade-off between changing pipe diameter for a specific flowrate while keeping physical pipe slope constant, and changing physical pipe slope for the same flowrate while keeping the pipe diameter constant.

To calculate costs associated with every possible combination of pipe diameters and excavation depth to find the optimum design for a storm sewer network without the use of a computer would be a very cumbersome task indeed. In fact, a minimum cost solution may never be found.

This paper presents a microcomputer program which assists the engineer …

A New Method For Broadband Surface Acoustic Wave Diffraction Analysis, Jacqueline Hanvey Hines

Retrospective Theses and Dissertations

This thesis describes an innovative technique for determining the impulse response of a SAW device including the effects of diffraction on both isotropic and anisotropic substrates. The approach presented is unique in that it determines the point-to-point impulse response for the isotropic case using the two-dimensional wave equation, and utilizes a double integral reduction technique to determine the tap-to-tap response, thereby significantly reducing the complexity of the calculations involved. An extension is then made to describe the impulse response of two cascaded transducers of arbitrary geometry, along with some simplifying cases. Previous attempts to model diffraction effects generally utilized either …

Hardware Algorithms For Data Compression, N. Ranganathan

Retrospective Theses and Dissertations

Data compression is the reduction of redundancy m data representation in order to decrease storage and communication costs. Data compression techniques have been used in practice primarily through software implementations which fail to meet the speed and performance requirements of current and future systems. This Ph.D. dissertation presents a set of hardware algorithms for compression and decompression techniques and the results of detailed simulations performed to quantify the effects of incorporating such hardware in various architectural environments. A new pipelined algorithm for data compression applicable to static binary encoding schemes is presented. A fast hardware algorithm for decompression that uses …

Optical Interferometric Formation Of Phased Array Antenna Footprint/, John E. Sherwood

Retrospective Theses and Dissertations

A 40 dB gain RF Low Noise Amplifier (LNA) matched to a photodiode input is designed using TOUCHSTONE (S-parameter based CAD software), built, and tested. The RF LNA formed the detector of a Mach-Zehnder interferometer constructed with single mode fiber, coupler, Gradient Index Rod Acousto-optic modulator (ADM) . (GRINROD) lenses, and an The ADM is used to frequency shift the optical frequency by 125 MHz, and the motion of a GRINROD lens is used to produce an optical phase shift that is recovered at the detector as an electrical phase shift by using heterodyne detection . Finite Hankel transforms are …

Parametric Shape Generation Of Aerodynamic And Structural Objects For Aerodynamic, Structural And Radar Cross-Section Analysis, Franklin C. Basile

Retrospective Theses and Dissertations

This thesis describes the design and development of software to parametrically build three-dimensional aerodynamic objects or shapes for various engineering design and analysis activities. The software is designed to generate and display sufficient geometric output to completely define the object. Parameters are entered through a prompting sequence which determines the type of object and the amount of geometry needed to describe the object. Geometry created by this program will act as the baseline model for aerodynamic , structural, and radar cross-section analysis. An integral part of the program is the complete 3-D viewing capability. Interactive global display capability allows for …