Digital Commons Network^™

A Case Study In Software Reuse: The Rntds Architecture, Barry J. Stevens

Computer Science Theses & Dissertations

It has been asserted that the most significant gains in software productivity will come from increased levels of software reuse. Some economic models for predicting savings through software reuse exist, but none are based on actual project experience. This paper surveys those models and presents the results of a case study, the Restructured Naval Tactical Data Systems (RNTDS) architecture, in the light of those models. According to the models, software reuse via the RNTDS architecture has enabled the production of fourteen major computer programs at five to twenty-one percent of the cost to create them without software reuse. Organizational characteristics …

Sleep Patterns And The Behavior Of Children In The Second-, Third-, And Fourth-Grades In Urban Public Schools, Yolanda Cardelli Hampel

Theses and Dissertations in Urban Services - Urban Education

This investigation examined the relationship between nocturnal sleep patterns and behaviors in the classroom of seventy-four girls and fifty-nine boys from second-, third-, and fourth-grades attending five urban public schools in Norfolk, Virginia.

The dependent variables were the classroom behavior that was subdivided into five personality areas for objective assessment of the student's adjustment areas labeled self, social, school, home, and physical. The objective assessment was observed and documented on a seventy-eight item questionnaire by their primary classroom teachers who were familiar with the subjects behavior. The parents observed and recorded data on a sleep log listing independent variables such …

Vorticity Dynamics Of Seasonal Variations Of The Antarctic Circumpolar Current From A Modeling Study, John M. Klinck

CCPO Publications

A one-layer numerical model was developed to analyze the vorticity dynamics of the seasonal variations of currents in the Southern Ocean. The model includes the continental geometry and bathymetry of the Southern Ocean and is forced by monthly climatological wind stress. Five cases are considered that compare (i) circulation over a flat bottom to that with bathymetry, (ii) effects of zonally averaged wind stress forcing versus the climatological forcing and (iii) anomaly wind stress (winds with the annual mean removed) versus the full stress. The individual terms in the vorticity conservation equation are calculated from the model solution along two …

Domain Limitations And Interface Requirements For Expert Developed Knowledge Based Systems, Bernard Lee Lewis

Engineering Management & Systems Engineering Theses & Dissertations

The expanded use of graphical, case-based and object oriented techniques in expert systems creation has made it more practical for domain experts to develop their own applications. This thesis focuses on the elements necessary in an expert/developer interface and looks at various forms and techniques that exemplify such an approach. The spreadsheet metaphor is used for an interface or managed set of interfaces that a domain expert can use in building his own expert system or prototype. criteria are established for such interfaces and recent commercial offerings that make expert-created knowledge-bases more practical are reviewed for techniques that qualify. Approaches …

Approaches To High Speed Networks, Frank Charles Paterra

Computer Science Theses & Dissertations

This work investigates possible methods by which existing potentially available communication bandwidth can be used by communication intensive applications. Presently fiber optic media are available that can provide multiple gigabits of throughput. Unfortunately, because of the computation overhead required to insure that data are reliably transmitted this capacity has not been tapped.

A survey of work toward enabling the use of the potential bandwidth is presented. The parallel paradigm is identified as a strong candidate for providing significant increases in system usable bandwidth. Performing communication processing in parallel, however, presents the developer with several implementation options. These options are considered …

Community Structure Of The Macrobenthos In Back Bay, Virginia, Michael F. Lane

Biological Sciences Theses & Dissertations

A study of the subtidal macrobenthos in Back Bay, Virginia was conducted to examine community structure in relation to sedimentary and water quality characteristics. Samples were collected in August and November of 1987 and February and May of 1988 at ten stations.

Three site groups and three temporal groups were identified by cluster analyses of species abundance. Species composition between site groups was relatively homogeneous and eight species accounted for most of the variation between site groups. A comparison of plots of the biological and physical data in discriminant space suggested that variations in the biological data between site groups …

The Geomorphology Of Alluvial Fan Deposits On The West Flank Of The Blue Ridge, Augusta County, Virginia, Debra Lynn Duffy

OES Theses and Dissertations

Large coalescing alluvial fans mantle the carbonate and shale formations west of the Blue Ridge mountains near Stuarts Draft, Virginia. Fan sediments are predominantly boulder and cobble gravels derived from the Antietam Quartzite, The fan complex consists of three alluvial units of significantly different ages. The surface of each fan unit was mapped using relative geomorphic position, soil color, clay content and thickness of Bt horizons, clast weathering, and degree of removal of depositional surfaces by stream incision. A five-category quartzite clast weathering scale developed for this study was very effective as a measure to distinguish map units. Stratigraphic data …

Reactions Of Aqueous Chlorine With Valine In Model Solutions And In Wastewater, Erika Forrer Mccormick

Chemistry & Biochemistry Theses & Dissertations

Solutions of the amino acid valine were chlorinated to seven chlorine-to-nitrogen mole (Cl/N) ratios and analyzed by high performance liquid chromatography, gas chromatography/mass spectroscopy, infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The chlorination products found were N-chlorovaline, isobutyraldehyde, isobutyronitrile, and N-chloroisobutyraldimine. Their product distribution depends on the level of chlorination and pH. The main products identified at the lower CI/N mole ratios were N-chlorovaline and isobutyraldehyde, whereas at the higher CI/N mole ratios isobutyronitrile and N-chloroisobutyraldimine were identified as the main products. The concentration and the chlorination products of valine in municipal wastewater were also determined. The chlorination products of …

Computer Simulation Techniques To Assess Bias And Precision In The Roving Creel Survey Estimator, David L. Wade

Biological Sciences Theses & Dissertations

Fisheries scientists use roving creel survey methods to estimate total catch and total effort of recreational fisheries. Bias in the roving creel estimators had been known to the scientific community, but it had not been quantified. I developed a roving-creel-survey computer simulation model to investigate the bias and precision of roving creel estimators, and estimated parameters for the model based on field observations from the blue crab (Callinectes sapidus) fishery of the Chesapeake Bay. The computer model was used to identify bias in roving-creel effort and catch estimators and to demonstrate survey methods that will reduce this bias. …

Linearized Dynamics Of Space Structures With Articulated Appendages, Gopichand Koganti

Mechanical & Aerospace Engineering Theses & Dissertations

The inherent difficulties of the conventional spacecraft design, which first considered the optimization with respect to structural variables and then with respect to control variables, have led to the concept of Controls-Structures Interactive Design. The success of the CSI design of Space structures without articulated appendages has prompted the extension of the CSI design to systems with articulated appendages. The presentation is of two parts, the first part deals with the derivations of the equations of motion and the second part deals with the eigenvalue/vector approximations.

Three approaches, namely: the multibody approach, the finite element based approach with hinge joints …

Experimental Study Of Transition In A Supersonic Free Shear Layer, Rudolph A. King

Mechanical & Aerospace Engineering Theses & Dissertations

The transition behavior of a free shear layer above a cavity with high and low levels of freestream acoustic disturbances has been investigated at Mach 3.5 in the Supersonic Low-Disturbance Pilot Tunnel located at NASA Langley Research Center. Schlieren photography, mean pitot pressure data, and hot-wire surveys were used to detect transition locations. The transition Reynolds numbers obtained were between Re_Tr = 3.6 x 10⁵ and 5.3 x 10⁵ in good agreement with conventional ("noisy") wind tunnel results. The study indicated that the effects of a decrease in freestream noise on Re_Tr were minimal but, as …

Population Dynamics Of Feral House Mice And Meadow Voles On A Dredge Disposal Site, Georgia E. Kratimenos

Biological Sciences Theses & Dissertations

The population dynamics of two species was studied for one year on Craney Island in Portsmouth, Virginia. This dredge disposal site provided good habitat for the house mouse, Mus musculus, whose opportunistic behaviors can withstand the sudden changes in a dynamic environment. Although the site was not optimal habitat, a population of Microtus pennsylvanicus, the meadow vole, was sustained there. Of the seven species of small mammals captured, 65% were house mice and 28% were meadow voles. Meadow voles were more successful at establishing short periods of residency than were house mice; on average, each meadow vole was …

Osteoinductivity Of Demineralized Bone: A Quantitative In Vitro Assessment, Yihong Zheng

Biological Sciences Theses & Dissertations

Acid demineralized bone (DMB) implanted in extraosseous sites induces bone formation. In vivo studies have shown that DMB stimulates the differentiation of mesenchymal cells into osteogenic cells. In this study an in vitro system was developed to demonstrate the osteoinductivity of DMB quantitatively. This in vitro working system was used to assess the osteoinductivity of variously processed DMB products as a means to evaluate their processing protocols. A human dermal fibroblastic (HDF) cell line was initiated from tissue explants as a working model, along with a human periosteal (HPO) cell line as a control. Ground DMB processed by LifeNet Transplant …

A Laboratory Study Of Predation On The Trinidadian Guppy, Poecilia Reticulata, By Two Natural Piscine Predators: Effects Of Predator Size, Prey Size, And Habitat Complexity, Hayden Thomas Mattingly

Biological Sciences Theses & Dissertations

Test populations of different-sized guppies, Poecilia reticulata, were exposed to individuals of two natural predatory species, the pike cichlid Crenicichla a/ta and the killifish Rivulus harti, under conditions of varying prey (guppy) density and habitat complexity in the laboratory. Rivulus fed most frequently on newborn and juvenile guppies < 14 mm. Crenicichla consumed more and larger guppies than did Rivulus. The mean guppy size eaten by Crenicichla was dependent on the length of the individual predator, but as a group, the 15 Crenicichla tested were non-selective with respect to guppy size and gender. The prey gender preference of Rivulus could not he determined …

The Identification, Distribution, And Status Of The Threatened Dismal Swamp Shrew (Sorex Longirostris Fisheri), Thomas M. Padgett

Biological Sciences Theses & Dissertations

Southeastern shrews (Sorex longirostris) were trapped throughout southeastern Virginia and northeastern North Carolina to determine if any morphological characters could

be identified that would aid in the identification and distribution of the threatened subspecies Sorex l._ fisheri, endemic to the Great Dismal Swamp, the more upland nominate subspecies Sorex l. longirostris, and possible intergrades between the two subspecies. Animals were classified a priori into three groups, based on their location of capture. Animals collected from the Great Dismal Swamp National Wildlife Refuge (GDSNWR) and associated bottomland habitats were designated as "fisheri", animals collected farthest from the Swamp as "longirostris", and …

Study Of Cathodoluminescence In Semiconductors, Mandakini V. Kale

Electrical & Computer Engineering Theses & Dissertations

Cathodoluminescence in Zn doped GaAs and ZnSe, the materials of interest for electron-beam controlled semiconductor switches, has been investigated. A new diagnostic technique, using telescopic setup of lenses, was developed to study the spatially resolved cathodoluminescence. The setup eliminated the light, other than rays from the sample, parallel to the optical axis, resulting in an enhanced spatial resolution. At high e-beam energies, light was detected, from the Zn layer region in the GaAs. It is proposed to be due to the radiative recombination of electron-hole pairs, created by the e-beam. For the polycrystalline ZnSe no light emission was detected. This …

The Theology Of Father Brown, Catherine Miles Flynn

Institute for the Humanities Theses

This thesis explores the theological thought of G. K. Chesterton, particularly as it is found in his detective short stories about Father Brown. In his other works (e.g., Orthodoxy, Heretics, and his many books of essays), the theology of Chesterton is obvious. However, in the light, whimsical Father Brown stories the theology expressed is often profound, but underrated if not ignored by his critics. Specific examples from his stories will be used to highlight the theological points within the mysteries.

The life and times of Chesterton are discussed as having highly influenced his thought. His unconventional religious upbringing, in particular, …

Ninety-Nine And One-Half, Deborah R. Williamson

Institute for the Humanities Theses

Ninety-nine and One-half is a novella about a young man's journey from self-doubt to self-revelation which parallels his physical journey from a coma to an awakening. In twenty spare chapters the memories of his life before the coma are intertwined with the actions of his family and friends after he becomes comatose. Through the young man's memories and the reflections about him by the other characters, the reader sees what has led the young man to an almost fatal indecision. The resolution of the novella comes when the young man adequately distances himself from the guilt, fear, and unhappiness that …

Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis

Chemistry & Biochemistry Theses & Dissertations

Catalysts composed of platinum and/or palladium on tin (IV) oxide supports, with and without silica gel, as well as catalysts composed of gold on manganese oxide, have been developed for the recombination of carbon monoxide and oxygen to form carbon dioxide for use in carbon dioxide lasers. A thermogravimetric method and a differential scanning calorimetric method have been developed for the thermal characterization of these catalysts. The mass loss data and the enthalpy changes determined as the catalysts lost water were then related to existing activity data for these catalysts. No relationship was found between the thermal data and the …

Touch Her, Carol Jensen Bliefernich

English Theses & Dissertations

Touch Her is a collection of twenty-two poems dealing with the death of a parent loss. and the subsequent effects of The poems progress toward an exploration of the elements of viable relationships.

The Effects Of A Commercial Nutritional Supplement Combining Amino Acids, Glutamine, Carnitine And B-Vitamins On The Physiological Responses To Ultraendurance Triathlon Training, Performance And Recovery, Mary V. Mitchell

Human Movement Studies & Special Education Theses & Dissertations

In a placebo, double blind, randomized design, five male triathletes participated in a simulated triathlon which examined the physiological responses of a commercial nutritional supplement. The supplemental protocol included 7.1 gm·d^-1 of an amino acid complex with B-vitamins (AA) and between 2.2-7.3 gm·d^-1 META-MAX™ containing leucine, isoleucine, valine, glutamine and carnitine in which quantities were based on the athletes training volume. A maltodextrin carbohydrate replacement drink was also included in the protocol. The placebo was an isocaloric lactose substance. The supplements were ingested for 14 d prior to the simulated triathlon and then for 3 d after the …

Processes Affecting The Behavior Of Redox-Sensitive Elements In Chesapeake Bay, Maria Lourdes San Diego-Mcglone

OES Theses and Dissertations

Several processes can affect variations in the chemical composition of an estuary, including (1) biogeochemical reactions in the water column, (2) advective transport, and (3) diffusion from underlying sediments.

The purpose of the study was to establish whether estuarine redox reactions are controlled by a complex interaction of processes 1 to 3. Short-term and long-term studies were conducted in Chesapeake Bay. Redox species involved in redox cycling include oxygen, iron, manganese, hydrogen sulfide, nitrogen species, arsenic and antimony species, while phosphate is indirectly involved in redox cycles. Silicate was used as a non-redox tracer.

For the short-term study, a Lagrangian …

An Examination Of The Effects Of An Intergenerational Reading Workshop On The Listening Comprehension Of At-Risk Pre-Kindergarten Students, Marycarolyn G. France

Theses and Dissertations in Urban Services - Urban Education

A surge of interest in working with parents to help their children build prerequisite language skills that would prevent reading failure has developed in recent years. The challenge of preventing reading failure in students is exacerbated when parents themselves have limited skills in reading. In recognition of this fact, schools and other institutions have begun to provide intergenerational programs to teach parents and children together. The workshop which is the subject of this study is one such program.

Thirteen parents and their pre-kindergarten children, who had been identified by the school as at-risk students, were exposed to an intergenerational reading …

Lava-Seawater Interactions At Shallow-Water Submarine Lava Flows, Francis J. Sansone, Joseph A. Resing, Gordon W. Tribble, Peter N. Sedwick, Kevin M. Kelly, Ken Hon

OES Faculty Publications

Hydrothermal plumes associated with nearshore lava flows from Kilauea Volcano, Hawaii were studied on five occasions during 1989-1990 to address the current lack of data on direct lava-seawater interactions. The following enrichments were found in the sea-surface hydrothermal plumes above the active underwater lava flows: H₂, 15,000x ambient seawater concentrations; Mn, 250x; and Si, 20x. Water temperatures reached 46°C. Lower concentrations and temperatures were observed in the plumes with increasing distance from shore, with H₂, Si, and Mn concentrations linearly related to seawater temperature. Unlike deep sea spreading center hydrothermal plumes, no CH₄ enrichment was …

A Study Of The Planning Process Utilized By Urban School Divisions In Constructing Public Schools In The State Of Virginia, 1984-1989, Patricia Liverman Powers

Theses and Dissertations in Urban Services - Urban Education

This research tested utilization of the "team approach" to planning for new school construction. The "team approach" is characterized by seven essential variables. To successfully plan a new school building, educators must: (1) involve more than one individual in collecting data; (2) provide quantitative data to the architect; (3) provide qualitative data to the architect; (4) provide data to the architect in advance of design; (5) provide data to the architect in written form; (6) provide original data, not prototype data; and (7) provide data which is used by the architect. Collective use of all seven variables constitute the "team …

The Parties Quarrae, Michael E. Malone

Institute for the Humanities Theses

During Thomas Jefferson's educational days in Williamsburg, Virginia, he was fortunate to have the association with three learned men, William Small, George Wythe, and Lt. Governor Francis Fauquier. The men met often at the governor's palace during the years 1760-64. Jefferson referred to their association as the "parties quarrae."

Most historians agree that the time spent with Small, Wythe, and Fauquier had profound influence on the establishment of Jefferson's "enlightenment" philosophy. Little, however, is known about the details of the regular meetings in the palace.

The focus of this creative project is the fictional discovery of Jefferson's "lost" Autobiography, finished …

The Solution Of A Singular Integral Equation Arising From A Lifting Surface Theory For Rotating Blades, Mark H. Dunn

Mathematics & Statistics Theses & Dissertations

A technique is presented for the solution of a linear, two dimensional, singular, Volterra integral equation of the first kind. The integral equation, originally developed by Farassat and Myers, is derived from the basic equations of linearized acoustics and models the lifting force experienced by an infinitesimally thin surface moving tangent to itself. As a particular application, the motion of modern high speed aircraft propellers (Advanced Technology Propellers) is considered. The unknown propeller blade surface pressure distribution is approximated by a piecewise constant function and the integral equation is solved numerically by the method of collocation. Certain simplifying assumptions applied …

J. Robert Oppenheimer And His Role In The Development Of The United States Nuclear Weapons Policy 1945-1953, Craig M. Harris

History Theses & Dissertations

J. Robert Oppenheimer played a highly visible role in the development of nuclear weapons policy for the United States. He was very influential in President Harry S. Truman's Administration after the Second World War. Following the Soviet Union's first atomic bomb blast in August 1949, Oppenheimer became out of step with those who made nuclear weapons policy. He continued to give advice on disarmament issues. In 1953, the first year of Dwight D. Eisenhower's Administration, Oppenheimer questioned the utility of the Superpower's nuclear arms build up, particularly the hydrogen bomb, while leaving the American people ignorant of the impact such …

Using Socio-Demographic Characteristics To Evaluate The Program Outcome Of Job Training Partnership Act Clients, Denise Vanasse Siegfeldt

Theses and Dissertations in Urban Services - Urban Management

The study was conducted to determine if there was a relationship between socio-demographic characteristics of Job Training Partnership Act (JTPA) Title II-A applicants who were determined JTPA eligible, assessed and counseled, and subsequently referred by a counselor for on-the-job training (OJT), and their program outcome, as designated by (1) positive and negative terminations; and (2) enrollments and nonenrollments. The study was conducted on clients served by the Job Training Services (JTS), one of the Service Delivery Areas (SDA-13) in the State of Virginia. JTS is located in a largely urban area of the State.

The program outcome evaluation consisted of …

Parallel-Vector Computation For Geometrically Nonlinear Frame Structural Analysis And Design Sensitivity Analysis, Majdi A. Baddourah

Civil & Environmental Engineering Theses & Dissertations

Parallel-vector algorithms are presented for solving the geometrically nonlinear structural problems and obtaining design sensitivity information. A new algorithm is also presented for parallel generation and assembly of the finite element stiffness and mass matrices. The presented assembly algorithm is based on a node-by-node approach rather than the more conventional element-by-element approach. Three different methods, Newton Raphson, Modified Newton Raphson, and the BFGS, are used in the analysis of the nonlinear structural problems. A study is made to determine the performance of each of the mentioned methods in a parallel-vector computer environment. Medium to large-scale, practical problems are solved to …