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Full-Text Articles in Physical Sciences and Mathematics

General Methods For Analyzing Machine Learning Sample Complexity, Christoph Cornelius Michael Jan 1994

General Methods For Analyzing Machine Learning Sample Complexity, Christoph Cornelius Michael

Dissertations, Theses, and Masters Projects

During the past decade, there has been a resurgence of interest in applying mathematical methods to problems in artificial intelligence. Much work has been done in the field of machine learning, but it is not always clear how the results of this research should be applied to practical problems. Our aim is to help bridge the gap between theory and practice by addressing the question: "If we are given a machine learning algorithm, how should we go about formally analyzing it?" as opposed to the usual question: "how do we write a learning algorithm we can analyze?".;We will consider algorithms …


Comparative Toxicity Of Creosote And Creosote Contaminated Sediments, Padma T. Venkatraman Jan 1994

Comparative Toxicity Of Creosote And Creosote Contaminated Sediments, Padma T. Venkatraman

Dissertations, Theses, and Masters Projects

No abstract provided.


In Vitro And In Vivo Effects Of Chemotherapeutants On The Oyster Parasite, Perkinsus Marinus, Gustavo W. Calvo Jan 1994

In Vitro And In Vivo Effects Of Chemotherapeutants On The Oyster Parasite, Perkinsus Marinus, Gustavo W. Calvo

Dissertations, Theses, and Masters Projects

To investigate the potential of chemotherapeutants to control the oyster pathogen Perkinsus marinus, anticoccidial and antifungal compounds were tested in vitro on infected hemolymph and cultured P. marinus cells and in vivo on infected oysters. In addition, acute toxicity to oysters was determined for six anticoccidials. In vitro experiments with infected hemolymph consisted of 24 h exposure of 0.2 mL hemolymph aliquots to concentrations ranging from 100 mg/L to 0.01 mg/L of amphotericin-B, amprolium, arprinocid, cycloheximide, lasalocid, malachite green, monensin, sulfadimethoxine, and a potentiated sulfadimethoxine, followed by incubation in fluid thioglycollate medium (FTM) to determine prezoosporangia abundance. Lasalocid, malachite green, …


Deuteron Nuclear Magnetic Resonance Studies Of Molecular Motion In Solids, Tak Yan Tse Jan 1994

Deuteron Nuclear Magnetic Resonance Studies Of Molecular Motion In Solids, Tak Yan Tse

Dissertations, Theses, and Masters Projects

$\sp2$H-NMR is a powerful spectroscopic technique for investigating dynamics in solids. to extend the range of motional rates that can be quantitatively investigated, a new approach for measuring the quadrupolar spin-lattice relaxation time $T\sb{1Q}$ was developed. This uses a Broadband Jeener-Broekaert (BBJB) sequence with echo-detection, which avoids the frequency-discriminated excitation profile and spectral baseline distortion intrinsic to the conventional Jeener-Broekaert (JB) experiment. By combining the BBJB experiment with an Inversion-Recovery sequence with Quadrupole-Echo detection (IRQE), two independent longitudinal relaxation times, $T\sb{1Q}$ and $T\sb{1Z}$, can be measured. Spectral densities of motion $J\sb1(\omega\sb{o}$) and $J\sb2(2\omega\sb{o}$) are extracted from these relaxation times. The …


Characterization And Modeling Of Amino Epoxide Resins, Maria Anastasia Argiriadi Jan 1994

Characterization And Modeling Of Amino Epoxide Resins, Maria Anastasia Argiriadi

Dissertations, Theses, and Masters Projects

No abstract provided.


Global Phylogeography Of Yellowfin Tuna, Thunnus Albacares, And Mackerels Of The Genus Scomber, Daniel R. Scoles Jan 1994

Global Phylogeography Of Yellowfin Tuna, Thunnus Albacares, And Mackerels Of The Genus Scomber, Daniel R. Scoles

Dissertations, Theses, and Masters Projects

Intraspecific genetic relationships within yellowfin tuna, Thunnus albacares, and three mackerels of the genus Scomber were studied by restriction fragment length polymorphism (RFLP) analysis of mitochondrial DNA (mtDNA). The comparison of these scombrids, with different larval distributions, adult distributions, and vagilities, served to investigate the hypothesis that population structure in marine fishes results from geographic and physical oceanographic processes that limit dispersal of early life history stages. Samples of 20 yellowfin tuna were examined from each of five Pacific locations and one Atlantic location. MtDNA analysis with 12 informative restriction endonucleases demonstrated considerable genetic variation, as evidenced by overall nucleon …


Food, Feeding, And Length-Weight Relationships Of Young-Of-The-Year Striped Bass, Morone Saxatilis And Young-Of-The-Year White Perch, Morone Americana, Paul J. Rudershausen Jan 1994

Food, Feeding, And Length-Weight Relationships Of Young-Of-The-Year Striped Bass, Morone Saxatilis And Young-Of-The-Year White Perch, Morone Americana, Paul J. Rudershausen

Dissertations, Theses, and Masters Projects

No abstract provided.


The Role Of Predation On Zostera Marina L (Eelgrass) Seed Abundance, James Fishman Jan 1994

The Role Of Predation On Zostera Marina L (Eelgrass) Seed Abundance, James Fishman

Dissertations, Theses, and Masters Projects

No abstract provided.


Toxicity Resistance In Mummichog (Fundulus Heteroclitus) From A Chemically Contaminated Environment, Cynthia A. H. Williams Jan 1994

Toxicity Resistance In Mummichog (Fundulus Heteroclitus) From A Chemically Contaminated Environment, Cynthia A. H. Williams

Dissertations, Theses, and Masters Projects

No abstract provided.


A Gis Spatial Analysis Of The Potential Conflict Between Submerged Aquatic Vegetation Management And The Development Of Shellfish Aquaculture In The Lower Chesapeake Bay, Laura Ann Grignano Jan 1994

A Gis Spatial Analysis Of The Potential Conflict Between Submerged Aquatic Vegetation Management And The Development Of Shellfish Aquaculture In The Lower Chesapeake Bay, Laura Ann Grignano

Dissertations, Theses, and Masters Projects

No abstract provided.


Directional Wave Spectra Using An Acoustic Doppler Current Profiler, William T. Stockhausen Jan 1994

Directional Wave Spectra Using An Acoustic Doppler Current Profiler, William T. Stockhausen

Dissertations, Theses, and Masters Projects

No abstract provided.


Collisions Of Atomic Hydrogen With Oxygen, Sulfur, Sodium And Halogen Anions At Low Energies, James Anthony Fedchak Jan 1994

Collisions Of Atomic Hydrogen With Oxygen, Sulfur, Sodium And Halogen Anions At Low Energies, James Anthony Fedchak

Dissertations, Theses, and Masters Projects

Total electron detachment and charge transfer cross sections, $\sigma\sb{\rm e}$(E) and $\sigma\sb{\rm ct}$(E), have been measured for collisions of the negative ions O$\sp{-}$, S$\sp{-}$, F$\sp{-}$, Cl$\sp{-}$, Br$\sp{-}$, I$\sp{-}$, Na$\sp{-}$, and K$\sp{-}$ with atomic hydrogen for laboratory energies ranging from 2 to 500 eV. For the systems F$\sp{-}$, Cl$\sp{-}$, Br$\sp{-}$, O$\sp{-}$ and S$\sp{-}$ + H, $\sigma\sb{\rm e}$(E) displays no barrier for associative detachment; the results are found to be adequately described by simple curve-crossing models based upon available intermolecular potentials, or by classical orbiting models which assume that the anion interacts with the H atom via an attractive potential of the …


Photoabsorption Spectra Of Hydrogen And Alkali Atoms In Electric Fields, Jing Gao Jan 1994

Photoabsorption Spectra Of Hydrogen And Alkali Atoms In Electric Fields, Jing Gao

Dissertations, Theses, and Masters Projects

A systematic study of the photoabsorption spectra of highly excited hydrogen and alkali atoms in electric fields is presented, based on the semiclassical closed-orbit theory. In most respects, hydrogen and alkali atoms behave similarly, because the excited alkali atoms have a single electron outside of a small ionic core, and the core only produces small shifts of energy levels and small phase shifts of scattered wave functions.;For hydrogen, the classical motion of the excited electron is regular and closed orbits can be enumerated. Above the zero-field ionization threshold, the system is rather simple. There is only one closed orbit, called …


Mechanisms Of Larval Spot Transport And Recruitment To The Chesapeake Bay, Deborah A. Bodolus Jan 1994

Mechanisms Of Larval Spot Transport And Recruitment To The Chesapeake Bay, Deborah A. Bodolus

Dissertations, Theses, and Masters Projects

The spot (Leiostomus xanthurus) is an important commercial and recreational species in Virginia. Recruitment of juveniles to the Bay is characterized by large interannual fluctuations, that can be explained by the sequence and direction of wind during various phases of the early life history. An environmentally-modified Ricker stock-recruitment curve was developed incorporating the southeasterly winds in November-December, the southerly winds in January-March, and the westerly winds in April-May. This model explained 81% of the variation and closely paralleled the VIMS Juvenile Spot Index. Spot from the Chesapeake Bay migrate south in fall to spawn near or south of Cape Hatteras. …


Size-Specific Fecundity Of The Sea Scallop, Placopecten Magellanicus, During One Spawning Period In The Mid-Atlantic Resource Area, Ryan B. Carnegie Jan 1994

Size-Specific Fecundity Of The Sea Scallop, Placopecten Magellanicus, During One Spawning Period In The Mid-Atlantic Resource Area, Ryan B. Carnegie

Dissertations, Theses, and Masters Projects

No abstract provided.


Mitochondrial Dna Variation In Natural And Cultured Populations Of The Bay Scallop, Argopecten Irradians (Lamarck) And The Calico Scallop, Argopecten Gibbus (Dall), Sandra Grace Blake Jan 1994

Mitochondrial Dna Variation In Natural And Cultured Populations Of The Bay Scallop, Argopecten Irradians (Lamarck) And The Calico Scallop, Argopecten Gibbus (Dall), Sandra Grace Blake

Dissertations, Theses, and Masters Projects

No abstract provided.


Use Of A Landscape-Level Approach To Determine The Habitat Requirements Of The Yellow-Crowned Night-Heron, Nycticorax Violaceus, In The Lower Chesapeake Bay, Ellen L. Bentley Jan 1994

Use Of A Landscape-Level Approach To Determine The Habitat Requirements Of The Yellow-Crowned Night-Heron, Nycticorax Violaceus, In The Lower Chesapeake Bay, Ellen L. Bentley

Dissertations, Theses, and Masters Projects

No abstract provided.


An Investigation Of The Late Quaternary Morphology Of Mobjack Bay, Va And Application Of A Facies Model, Donna Angela Milligan Jan 1994

An Investigation Of The Late Quaternary Morphology Of Mobjack Bay, Va And Application Of A Facies Model, Donna Angela Milligan

Dissertations, Theses, and Masters Projects

No abstract provided.


The Requirements Of Patentability As Applied To The Chemical Arts, Joy L. Bryant Jan 1994

The Requirements Of Patentability As Applied To The Chemical Arts, Joy L. Bryant

Dissertations, Theses, and Masters Projects

No abstract provided.


Perspectives On Nature: A Comparison Of The Views Of Thomas Jefferson And Henry David Thoreau, Stephanie Brewer Foley Jan 1994

Perspectives On Nature: A Comparison Of The Views Of Thomas Jefferson And Henry David Thoreau, Stephanie Brewer Foley

Dissertations, Theses, and Masters Projects

No abstract provided.


Polarization Transfer Coefficient Measurements In The Deuteron Breakup Reaction Hydrogen-1(Polarized Deuteron,Polarized Proton)X At 2.1 Gev, Naipor Eric Cheung Jan 1994

Polarization Transfer Coefficient Measurements In The Deuteron Breakup Reaction Hydrogen-1(Polarized Deuteron,Polarized Proton)X At 2.1 Gev, Naipor Eric Cheung

Dissertations, Theses, and Masters Projects

The polarization of the protons emerging at 0$\sp\circ$ from the inclusive deuteron breakup reaction $\sp1$H($\vec d,\vec p$)X was measured using a deuteron beam with kinetic energy of 2.1 GeV. The momentum of the protons was selected by the magnetic spectrometer SPES4 and the polarization was measured with the polarimeter POMME. This experiment was performed at eight different proton momenta. When those momenta are Lorentz transformed to the deuteron rest frame, they corresponded to values from 0.00 to 0.34 GeV/c. The result of the measurements is expressed in terms of polarization transfer coefficient which is defined as the ratio of the …


Glueball Wave Functions And Production Cross Sections, Anthony B. Wakely Jan 1994

Glueball Wave Functions And Production Cross Sections, Anthony B. Wakely

Dissertations, Theses, and Masters Projects

Three topics are studied in this dissertation.;Using QCD sum rules, I first calculate the first few moments of the distribution amplitude of the pseudoscalar glueball, a bound state of gluons. The distribution amplitude is the momentum wave function integrated over the transverse momentum. QCD sum rules are a method of finding hadronic parameters using perturbative QCD. I use an approximation in which the glueball is treated as a narrow resonance. The moments of the distribution amplitude then give the corresponding first few coefficients of the distribution amplitude for the glueball expanded in Gegenbauer polynomials. The distribution amplitude is rather close …


Causal Synchrony In The Design Of Distributed Programs, Sandra L. Peterson Jan 1994

Causal Synchrony In The Design Of Distributed Programs, Sandra L. Peterson

Dissertations, Theses, and Masters Projects

The outcome of any computation is determined by the order of the events in the computation and the state of the component variables of the computation at those events. The level of knowledge that can be obtained about event order and process state influences protocol design and operation. In a centralized system, the presence of a physical clock makes it easy to determine event order. It is a more difficult task in a distributed system because there is normally no global time. Hence, there is no common time reference to be used for ordering events. as a consequence, distributed protocols …


A Relativistic Model Of Pion Nucleon Scattering And Pion Photoproduction On A Single Nucleon, Yohanes Surya Jan 1994

A Relativistic Model Of Pion Nucleon Scattering And Pion Photoproduction On A Single Nucleon, Yohanes Surya

Dissertations, Theses, and Masters Projects

Pion nucleon scattering is described by a manifestly covariant wave equation in which the pion is restricted to its mass-shell. The kernel of the equation includes nucleon (N), Roper (N*), delta ({dollar}\Delta{dollar}) and {dollar}D\sb{lcub}13{rcub}{dollar} poles, with their corresponding crossed pole terms approximated by contact interactions, and contact {dollar}\sigma{dollar}- and {dollar}\rho{dollar}-like exchange terms. The {dollar}\pi NN{dollar} vertex is treated as a mixture of {dollar}\gamma\sp5{dollar} and {dollar}\gamma\sp\mu\gamma\sp5{dollar} coupling, with a mixing parameter {dollar}\lambda{dollar} chosen so that the dressed nucleon pole will be unshifted by the interaction. Chiral symmetry is maintained at threshold. The resonance contributions are fully unitarized by the equation, with …


Great Blue Herons And River Otters: The Changing Perceptions Of All Things Wild In The Seventeenth And Eighteenth-Century Chesapeake, Elise Helene Manning-Sterling Jan 1994

Great Blue Herons And River Otters: The Changing Perceptions Of All Things Wild In The Seventeenth And Eighteenth-Century Chesapeake, Elise Helene Manning-Sterling

Dissertations, Theses, and Masters Projects

No abstract provided.


Physical And Mechanical Behavior Of Amorphous Poly(Arylene Ether-Co-Imidazole)S And Poly(Arylene Ether-Co-Imidazole) Modified Epoxies, Patricia D. Roberts-Mcdaniel Jan 1994

Physical And Mechanical Behavior Of Amorphous Poly(Arylene Ether-Co-Imidazole)S And Poly(Arylene Ether-Co-Imidazole) Modified Epoxies, Patricia D. Roberts-Mcdaniel

Dissertations, Theses, and Masters Projects

Due to the high crosslink density of cured epoxy resins they generally lack damage tolerance. A significant amount of research has been expended to improve the toughness of epoxies. Research into the area of thermoplastic epoxy modifiers has begun to overcome some of the limitations of early methods of epoxy toughening (i.e. lower modulus and thermal stability).;This study examines the physical and mechanical properties of random poly(arylene ether-co-imidazole) (PAE-co-Is) and the characterization of epoxies modified with poly(arylene ether-co-imidazole)s.;Poly(arylene ether-co-imidazole)s exhibited the highest solubility in N,N,N{dollar}\rm\sp\prime,N\sp\prime,{dollar}-tetraglycidyl- 4,4{dollar}\sp\prime{dollar} diaminodiphenyl methane (TGMDA) based resins. The high molecular weight polymers caused significant decreases in …


Models For Water Outgassing From Metal Surfaces, Minxu Li Jan 1994

Models For Water Outgassing From Metal Surfaces, Minxu Li

Dissertations, Theses, and Masters Projects

In this study, the outgassing rate from an electropolished stainless steel surface following exposures to H{dollar}\sb2{dollar}O vapor under various conditions was measured. The results of the experiments showed that the outgassing rate is proportional to {dollar}p\sb0\sp{lcub}n{rcub}{dollar}, where {dollar}p\sb0{dollar} is the H{dollar}\sb2{dollar}O exposure pressure and n is about 0.25. The outgassing rate is not as strongly dependent on the system temperature as one would expect if the temperature is kept the same during exposure and pump-down. The outgassing rate is also a function of the exposure time for the first several hours of exposure, indicating that the adsorption saturation time is …


The Effects Of Contaminated Sediment On The Epidermal Goblet Cells Of The Mummichog, Fundulus Heteroclitus, Laurent C. Mézin Jan 1994

The Effects Of Contaminated Sediment On The Epidermal Goblet Cells Of The Mummichog, Fundulus Heteroclitus, Laurent C. Mézin

Dissertations, Theses, and Masters Projects

Secretion of mucus by epidermal goblet cells is an important first line of defense for teleosts. It protects them against many of the biological, physical and chemical insults they encounter in their environment. This project monitored changes in hemoglobin concentration in epidermal mucus and in the density, diameter and mucus quality of epidermal goblet cells in the mummichog, Fundulus heteroclitus, following exposure to creosote-contaminated sediment. Male fish (200) were exposed for 13 days in flowthough aquaria to either an uncontaminated reference sediment or contaminated sediment containing 30% Elizabeth River sediment. Fish were sampled on Days 0, 3, 7 and 13. …


Alternative Management Programs Within The Atlantic Sea Scallop Placopecten Magellanicus Fishery: Property Rights, Transferable Quotas And Fishing Effort, Niels E. Moore Jan 1994

Alternative Management Programs Within The Atlantic Sea Scallop Placopecten Magellanicus Fishery: Property Rights, Transferable Quotas And Fishing Effort, Niels E. Moore

Dissertations, Theses, and Masters Projects

No abstract provided.


Measurement Of In Situ Eelgrass Community Metabolism In Standing And Flowing Waters: Methods And Models, William James Seufzer Jan 1994

Measurement Of In Situ Eelgrass Community Metabolism In Standing And Flowing Waters: Methods And Models, William James Seufzer

Dissertations, Theses, and Masters Projects

No abstract provided.