Digital Commons Network^™

A Framework For Controlling Quality Of Sessions In Multimedia Systems, Alaa S. Youssef

Computer Science Theses & Dissertations

Collaborative multimedia systems demand overall session quality control beyond the level of quality of service (QoS) pertaining to individual connections in isolation of others. At every instant in time, the quality of the session depends on the actual QoS offered by the system to each of the application streams, as well as on the relative priorities of these streams according to the application semantics. We introduce a framework for achieving QoSess control and address the architectural issues involved in designing a QoSess control laver that realizes the proposed framework. In addition, we detail our contributions for two main components of …

An Alternative Method For Determining Adjusted Function Points As The Basis For Software Cost Estimating, William Alexander Eldred

Engineering Management & Systems Engineering Theses & Dissertations

As software costs become an increasingly higher percentage of total computer system costs, it becomes increasingly more important for software development managers to have the ability to predict development costs with reasonable accuracy early in the software development cycle. Software development cost estimates are based in large measure on software size. Function points are considered by many to be a de facto industry standard as a size metric. The function points technique, unlike lines-of-code, can be applied early in the software development cycle and is language independent. Critics claim that the function point “value adjustment factor,” which purports to capture …

Placement Of Piezoelectric Actuators For Active Control Of Vibration Using Modal Parameters, Xuegeng Zhu

Mechanical & Aerospace Engineering Theses & Dissertations

An equation is derived to model the piezoelectric actuators incorporation with flexible structures. This equation permits the comparison of the performance indices over the entire structure for a piezoelectric actuator with constant area, which is unachievable if the Finite Element Method is used for complicated structures.

An index has been developed for placement of piezoelectric actuator for control of vibration of a flexible structure. This index is derived from the definition of H2norm. Computation of the proposed index requires only the natural frequencies and corresponding mode shapes of the structures of interest. The method is well suited to large …

Ecology Of The Eastern Cottonmouth (Agkistrodon P. Piscivorus) At Back Bay National Wildlife Refuge: A Comparative Study Of Natural And Anthropogenic Marsh Habitats, Chad Lee Cross

Biological Sciences Theses & Dissertations

Mark-recapture sampling and radiotelemetry were used to investigate populations of the eastern cottonmouth, Agkistrodon p. piscivorus, in both natural and anthropogenic marsh habitats at Back Bay National Wildlife Refuge (BBNWR), Virginia Beach, Virginia from autumn 1995 to late spring 1998. Mark-recapture subjects were captured, marked by ventral scale-clipping, and released back into the population. A modified Schnabel Census estimator was used to estimate population sizes and corresponding densities in both marsh systems based on a total of 244 captures of 222 individuals. Most snakes were found >0.05 in from water, but it was apparent that proximity to water played …

Locating A Mate In 3d: The Case Of Temora Longicornis, Michael H. Doall, Sean Colin, J. Rudi Strickler, Jeannette Yen

Arts & Sciences Faculty Publications

Using laser optics to illuminate high–resolution video–recordings, we revealed behavioural mechanisms through which males of the calanoid copepod species Temora longicornis locate females. Males of T. longicornis swam at significantly faster speeds than females along more sinuous routes, possibly reflecting adaptations to increase encounter with females. Upon approaching within 2 mm (i.e. two bodylengths) of a female's swimming path, males accelerated to significantly higher pursuit speeds. Pursuit trajectories closely traced the trajectories of females, suggesting that males were following detectable trails created by swimming females. Males of T. longicornis detected female trails up to at least 10 s old, and …

An Approach To Defining Greater Park Ecosystems And Its Application To Gros Morne National Park (Newfoundland), Karl Keough

Theses and Dissertations (Comprehensive)

Ecosystem management is an integrative, cooperative, adaptive approach to resource management that has evolved in response to the growing number of environmental and resource problems over the past several decades. One such problem, the threat to the world’s biodiversity, may be attributed to the destruction, degradation, and fragmentation of habitat resulting from the expanding human population, and the inability to set aside in strict nature reserves, sufficient habitat for wide-ranging mammals and fully functioning ecosystems. The Greater Park Ecosystem concept may be seen as the embodiment of ecosystem management in national parks and a response to the threat to biodiversity. …

Stakeholder Attitudes As A Resistance Toward Long-Range Management Of A Threatened Landscape: A Case Study Of Aggregate Use In The Township Of North Dumfries (Ontario), Kim Margaret Horrigan

Theses and Dissertations (Comprehensive)

The Township of North Dumfries is located in the rapidly expanding Municipality of Waterloo. This Township is in close proximity to Kitchener, Waterloo, Cambridge, Guelph, Hamilton, and is halfway between London and Toronto, with the primary east-west Highway 401 running through the Township. It is an unique area in that it is characterized by an abundance of prime agricultural lands, Environmentally Sensitive Policy Areas, and wetlands. In addition, the Township is underlain with a large quantity of good quality glacially derived aggregate materials. Land use conflicts have increased as a result of aggregate developers’ pressures on the resources of this …

Managing Urban Water Resources In A Developing Economy: The Case Of Owerri, Nigeria, Lawrence Chidi Anukam

Theses and Dissertations (Comprehensive)

Projections indicate that the disparity in population numbers will widen further by the year 2025 when the global population is expected to be 8.5 billion, and at that time about 84% will be living in the developing countries (World Resources Institute, 1992). The greatest proportional increase will occur in Africa, where the population is projected to nearly triple, from a 1990 level of 642 million to 1.6 billion in 2025. In 1997, the population of Nigeria alone was about 100 million, making it the largest country, in terms of population, in Africa. From 1960 to 1990, the average annual population …

An Efficient Library For Parallel Ray Tracing And Animation, John Edward Stone

Masters Theses

"A parallel ray tracing library is presented for rendering high detail images of three dimensional geometry and computational fields. The library has been developed for use on distributed memory and shared memory parallel computers and can also run on sequential computers. Parallelism is achieved through the use of message passing and threads. It is shown that the library achieves almost linear scalability when run on large distributed memory parallel computers as well as large shared memory parallel computers.

Several applications of parallel rendering are explored including rendering of CAD models, animation, magnetic resonance imaging, and visualization of volumetric flow fields. …

Characterization Of Petroleum Fog Oil And Vegetable Oil Smokes, Andrew Oliver Larouche

Masters Theses

"Deception and concealment to gain tactical advantage in the battlefield has been an integral part of warfare. Smoke has been a common tool used for signaling, concealment of troop movement and weapon deployment. U.S. Armed Forces have made use of smokes in an organized manner since the 1st world war. Since then various materials such as white phosphorus, zinc chloride, diesel fuel and petroleum oil aerosols have been used to obscure military targets. For the past thirty years fog oil (FO) a medium distillate has been extensively used by the U.S. Armed Forces for generation of obscurant smokes (OS). During …

Harding University Catalog 1998-1999, Harding University

Harding Academic Catalogs

Academic catalog for the undergraduate programs at Harding University.

Harding University School Of Education Graduate Catalog, 1998-1999, Harding University

Harding Academic Catalogs

Academic catalog for the graduate education program at Harding University.

Measurement Of The Fraction Of Hadronic Z Decays Into Charm Quark Pairs, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The full statistics of hadronic Z decays collected with the ALEPH detector are analysed to measure, by three methods, the ratio, RcRc, of the partial decay width of the Z into cc¯cc¯ quarks to the total hadronic width. One method uses the inclusive pp and p⊥p⊥ spectra of electrons. The other two use a double-tagging technique to measure RcRc independently of the charm-tagging efficiency. In one, the tagging procedure uses the reconstruction of high momentum charmed mesons (D∗+D∗+, D+D+ and \({\rm D^0}$) to detect the charm quarks. In the other, a charm quark is tagged from the D∗D∗'s reconstructed in …

Patterns Of Organochlorine Pesticide Contamination In Neotropical Migrant Passerines In Relation To Wintering Range And Wintering Habitat, Jeffrey A. Klemens '98

Honors Projects

Seventy-two Neotropical migrant passerines were analyzed for the presence of 17 organochlorine pesticide residues (aldrin; alpha-BHC; beta-BHC; gamma-BHC; delta-BHC; p,p'-DDD; p,p'-DDE; p,p'-DDT; dieldrin; endosulfan I; endosulfan II; endosulfan sulfate; endrin; endrin aldehyde; heptachlor- heptachlor epoxide; methoxychlor) using standard method of gas chromatography applied to bird tissues. Individuals were colIected along the Mississippi River during May 1996 and represent 11 species (Catharus ustulatus; Geothlypis trichas; Protonotaria citrea; Mniotilta varia; Contopus virens; Dendroica petechia; Ernpidonax minimus; Passerina cyanea; Myiarchus crinitus; Vireo gilvus). The contaminants most frequently detected were p,p'-DDE, dieldrin, and heptachlor epoxide. No significant difference was found between male and female …

The Total Synthesis Of A Conformationally Constrained Organophosphorus Analog Of Acetycholine, Justin Mergott '98

Honors Projects

We propose the total synthesis of a conformationally constrained organophosphorus analog of acetylcholine (5, Scheme 5). This compound will contain two crural centers, one being the phosphorus atom and the other being the pyrrolidine ring carbon beta to the phosphorus atom. The chiral beta carbon is conformationally constrained because it is part of the pyrrolidine ring. Studies with such a compound should allow us to make substantial progress towards the clarification of the stereospecificity of AChE inhibition by OP compounds and eventually help us understand more about the structure of the AChE active site. The synthesis begins with Cbz-L-proline methyl …

Logiccity: On-Line Digital Logic Simulator, Jihad Z. Almahayni

Open Access Master's Theses

A primary challenge for science educators is to develop ways to help students understand new ideas that cannot be directly observed. The application of computer simulations is one method instructors may use to address the problem of teaching for conceptual understanding. The use of computer simulations for science teaching is increasing steadily because simulations provide students with the opportunity to witness or "perform" experiments that might otherwise be too expensive, too time consuming, or too dangerous for them to do in the lab. Simulation, in general, is a very effective way for both a student and a professional to visualize …

Database Security: Evaluation Of A Multi-Policy Access Control Model, Fei Dong

Dissertations and Theses @ UNI

As an increasing number of organizations become dependent on access to their data stored in the database, the need for adequate security measures is becoming more and more critical. Enforcing data protection means safeguarding data from unauthorized or improper disclosures or modifications. Access control policies should be independent of the mechanisms that will implement the physical control of access: this allows control mechanism to be available for different policies. Although considerable work was done on access control models and related mechanisms for databases (Castano & Fugini, 1994), current access control models and mechanisms are not flexible enough to meet the …

The International Enforcement Of Software Copyrights And Patents, Siehnai F. Williamson

Computer Law Review and Technology Journal

Upon graduating with a computer science degree, Shannon Smith and her classmates started their own educational computer software firm called ABC Software (ABC). ABC observed that the computer software industry had grown exponentially since the 1980s due in part to industry-wide standards (like the Windows® platform) and the declining costs in computer hardware that have increased demand for computer products. Because ABC believes the software industry is knowledge-based, ABC need incur little research and developmental costs. ABC's ability to protect its software will be the determining factor in deciding where to distribute its products. Since the very nature of computer …

Remote Sensing Of Commercial Aircraft Emissions, Peter J. Popp, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

A Comparison Of Prospective Memory And Executive Processes In Patients With Subcortical Illness, Milan Elmer "Trey" Folkers Iii '98

Honors Projects

Dementia is a common disorder affecting neuropsychological function in several spheres of mental activity including language memory, visuospatial function, and cognition. Studies into the cognitive deficits associated with dementia have allowed researchers to rank disorders into two subclasses: cortical and subcortical dementia. Cortical dementias such as Alzheimer's disease have been the focus of a plethora of studies. Subcortical dementia, which is commonly found in Parkinson's disease and Huntington's disease patients, is marked by bradyphrenia, visuospatial abnormalities, personality alterations, memory disturbances primarily involving recall but not recognition, and loss of executive functions. The most recent disorder to be classified as a …

Problem Based Learning And Its Use On The Automotive Engineering Design Course At Coventry University, Aj Robotham

School of Engineering, Computing and Mathematics

The Automotive Engineering Design course at Coventry University has been in operation since October 1989 and has earned a reputation for creating able engineers well prepared for industry. When originally conceived, a problem led approach to learning was adopted across the course. This approach best enables the course objectives to be satisfied. However, there is nothing new about problem-based learning for engineering design educators but for our engineering science colleagues a degree of novelty has been encountered by this approach. But is the success of the course purely down to this teaching and learning approach? This paper will discuss the …

Creating Practitioners Of Design For Quality Through Education, Aj Robotham

School of Engineering, Computing and Mathematics

The WDK Workshop in Pedagogics in Design Education provides an ideal opportunity to reflect upon my experiences of teaching engineering design at tertiary level and review some of the fundamental elements of design education practice. In particular, I will reflect upon the design experience provided at Coventry University where I taught until quite recently.

An Investigation Into The Development Of Engineering Students' Conceptual Understanding Of Mathematics, Wendy Mary Maull

School of Engineering, Computing and Mathematics Theses

Following widespread concern over an apparent decline in the mathematical skills of engineering students, this study employed survey and observation methods to investigate the ways in which engineering students understand mathematical concepts, and to compare these with the concepts held-by students of mathematics. It was found that the engineering students employ a different vocabulary from mathematics students in discussing mathematics, and that their understanding of mathematical concepts develops differently from mathematics students both in response to teaching (which appears to be a transitory effect) and as their experience gives meaning to the ideas in life outside study. These findings are …

Annual Report 1 September 1997 - 31 August, 1998, Dublin Institute Of Technology

DIT Annual Reports

No abstract provided.

Image Analysis And Prenatal Screening, Jian'an Luan

School of Engineering, Computing and Mathematics Theses

Information obtained from ultrasound images of fetal heads is often used to screen for various types of physical abnormality. In particular, at around 16 to 23 weeks' gestation two-dimensional cross-sections are examined to assess whether a fetus is affected by Neural Tube Defects, a class of disorders that includes Spina Bifida. Unfortunately, ultrasound images are of relatively poor quality and considerable expertise is required to extract meaningful information from them. Developing an ultrasound image recognition method that does not rely upon an experienced sonographer is of interest. In the course of this work we review standard statistical image analysis techniques, …

The Fatigue Properties Of Spring Steel, Daniel Gerhardus Hattingh

School of Engineering, Computing and Mathematics Theses

The nature and scope of this thesis can be divided into three categories, namely stress distribution modelling in coil springs; fatigue and failure analysis, an investigation into measurement of residual stresses and the relation to fatigue life. The operation of springs is directly concerned with the theories of torsion and bending which makes the better understanding of these theories essential. The first part of the thesis is involved with a mathematical evaluation of these theories and a case study of an isolated loop of a coil spring. The mathematical modelling is verified by measuring the strain levels in a coil …

Latent Variable Generalized Linear Models, Jane Creagh-Osborne

School of Engineering, Computing and Mathematics Theses

Generalized Linear Models (GLMs) (McCullagh and Nelder, 1989) provide a unified framework for fixed effect models where response data arise from exponential family distributions. Much recent research has attempted to extend the framework to include random effects in the linear predictors. Different methodologies have been employed to solve different motivating problems, for example Generalized Linear Mixed Models (Clayton, 1994) and Multilevel Models (Goldstein, 1995). A thorough review and classification of this and related material is presented. In Item Response Theory (IRT) subjects are tested using banks of pre-calibrated test items. A useful model is based on the logistic function with …

The Manufacture Of Marine Propellers In Moulded Anisotropic Polymer Composites, Timothy John Searle

School of Engineering, Computing and Mathematics Theses

This thesis examines the feasibility of manufacturing small marine propellers from continuous fibre reinforced polymer composite materials. An appraisal of some current applications of composite materials in the marine industry is given, together with the moves shown towards the use of composites in the area of propeller design. It has been shown that manufacturing propellers in composite materials is theoretically more cost effective than traditional materials. The manufacturing route investigated is Resin Transfer Moulding, where some detailed investigations have highlighted some of the critical processing parameters necessary for successful production of laminates suitable for propellers and other high performance marine …

Enhanced Coding, Clock Recovery And Detection For A Magnetic Credit Card, Daniel Felix Smith

School of Engineering, Computing and Mathematics Theses

This thesis describes the background, investigation and construction of a system for storing data on the magnetic stripe of a standard three-inch plastic credit in: inch card. Investigation shows that the information storage limit within a 3.375 in by 0.11 in rectangle of the stripe is bounded to about 20 kBytes. Practical issues limit the data storage to around 300 Bytes with a low raw error rate: a four-fold density increase over the standard. Removal of the timing jitter (that is prob-' ably caused by the magnetic medium particle size) would increase the limit to 1500 Bytes with no other …

Investigation Into Submicron Track Positioning And Following Technology For Computer Magnetic Disks, Baolin Tan

School of Engineering, Computing and Mathematics Theses

In the recent past some magnetic heads with submicron trackwidth have been developed in order to increase track density of computer magnetic disks, however a servo control system for a submicron trackwidth head has not been investigated. The main objectives of this work are to investigate and develop a new servo pattern recording model, a new position sensor, actuator, servo controller used for submicron track positioning and following on a computer hard disk with ultrahigh track density, to increase its capacity. In this position sensor study, new modes of reading and writing servo information for longitudinal and perpendicular magnetic recording …