Physical Sciences and Mathematics Commons^™

Aloha-93 Measurements Of Intrinsic Agw Characteristics Using The Airborne Airglow Imager And Groundbased Na Wind/Temperature Lidar, G. R. Swenson, Michael J. Taylor, P. Espy, C. S. Gardner, X. Tao

All Physics Faculty Publications

Monochromatic Acoustic Gravity Waves (AGWs) with periods < 1 hour are a prevalent feature in the mesospheric airglow layers. These waves are important dynamically and energetically to the region where their temporal and spatial morphology are not well established. The purpose of this study is establish the intrinsic AGW characteristics over an extended region (as flown by the NCAR Electra aircraft) and to present the data in terms of the predicted spectral domain defined by the Brunt‐Vaisala frequency and the diffusive filtering limit proposed by Gardner [1994]. On October 21, 1993, observations were made from the NCAR Electra aircraft during a 6 hour flight in a large triangle N and W of Maui, for a integral distance of ∼3000 km. The entire area observed [∼1 M km²] had a monochromatic AGW propagating toward the NW and the western half had a SW propagating wave superimposed. These waves were also observed with the Michelson interferometer on the aircraft and an airglow imager at the Haleakala location during this time. Intrinsic phase velocities were computed where the Na Wind/Temperature (W/T) lidar at Haleakala provided a measure of the mean wind to compensate phase velocities observed with the imager. The data were tabulated and plotted in an AGW spectral reference frame and compared to cutoff conditions predicted by diffusive filtering theory.

An Investigation Of Intrinsic Gravity Wave Signatures Using Coordinated Lidar And Nightglow Image Measurements, Michael J. Taylor, Y. Y. Gu, X. Tao, C. S. Gardner, M. B. Bishop

All Physics Faculty Publications

Simultaneous observations of gravity waves using an Na wind/temperature lidar and a multi‐wavelength all‐sky nightglow imager were obtained, for the first time, during the ALOHA‐93 campaign. A novel investigation of intrinsic wave parameters has been made by combining measurements of the horizontal wave components imaged in four nightglow emissions (height range ∼80–100 km) with Na lidar soundings of the horizontal wind field and temperature profiles over the same height interval. On October 19 both instruments registered marked monochromatic wave motions. The intrinsic periods of several of these waves have been determined and were found to vary considerably with altitude, often …

Maximum Penetration Of Atmospheric Gravity Waves Observed During Aloha-93, G. R. Swenson, C. S. Gardner, Michael J. Taylor

All Physics Faculty Publications

Atmospheric Gravity Waves (AGWs) are subject to altitude propagation limits which are governed by the diffusion processes. Diffusion times and scales which exceed the wave period and wavelength define the limiting domain for AGWs. An expression is presented which defines the upper altitude limit to which AGWs can propagate given vertical diffusion constraints of the atmosphere. Airglow, lidar, and radar measurements are combined to characterize the intrinsic AGW parameters in the 80–105 km altitude region. A subset of AGWs (17) observed by airglow imagers during the ALOHA‐93 were made when simultaneous wind measurements were available and intrinsic wave parameters were …

Review Of Environmental Physics By Egbert Boeker And Rienk Van Grondelle, David W. Hafemeister

Physics

No abstract provided.

Enwrich: A Compute-Processor Write Caching Scheme For Parallel File Systems, Apratim Purakayastha, Carla Schlatter Ellis, David Kotz

Dartmouth Scholarship

Many parallel scientific applications need high-performance I/O. Unfortunately, end-to-end parallel-I/O performance has not been able to keep up with substantial improvements in parallel-I/O hardware because of poor parallel file-system software. Many radical changes, both at the interface level and the implementation level, have recently been proposed. One such proposed interface is \em collective I/O, which allows parallel jobs to request transfer of large contiguous objects in a single request, thereby preserving useful semantic information that would otherwise be lost if the transfer were expressed as per-processor non-contiguous requests. Kotz has proposed \em disk-directed I/O as an efficient implementation technique for …

Interaction Of An Expanding Plasma Cloud With A Simple Antenna: Application To Anomalous Voltage Signals Observed By Voyager 1, Voyager 2, Ice, And Vega Spacecraft, D. P. Sheehan, C. A. Casey, L. T. Volz

Physics and Biophysics: Faculty Scholarship

High‐velocity impacts of interplanetary dust grains with spacecraft can give rise to transient plasma clouds from the spacecraft bodies. It is believed these plasma clouds can affect spacecraft instruments. Laboratory results are presented demonstrating the interaction of small expanding plasma clouds with a simple antenna. Results corroborate the hypothesized origin of anomalous impulsive voltage signals recorded by Voyager 1 and 2 spacecraft during flybys of Saturn, Uranus, and Neptune, the International Cometary Explorer (ICE) during its flyby of comet Giacobini‐Zinner, and Vega during its flyby of comet Halley. Results suggest that preflight calibration of antenna‐plasma interactions may extend the range …

Expanding The Potential For Disk-Directed I/O, David Kotz

Dartmouth Scholarship

As parallel computers are increasingly used to run scientific applications with large data sets, and as processor speeds continue to increase, it becomes more important to provide fast, effective parallel file systems for data storage and for temporary files. In an earlier work we demonstrated that a technique we call disk-directed I/O has the potential to provide consistent high performance for large, collective, structured I/O requests. In this paper we expand on this potential by demonstrating the ability of a disk-directed I/O system to read irregular subsets of data from a file, and to filter and distribute incoming data according …

Management Of Pesticide Related Soil Contamination In Tulare County, California: Remediation And Prevention Options, Nickolas Keoni Akana

UNLV Theses, Dissertations, Professional Papers, and Capstones

The case study chosen for research is the Remedial Action Plan (RAP) summary report of Remedial Investigations of the Harmon Field contaminated site located near the town of Pixley, in Tulare County, California. "These reports were prepared in accordance with a directive from the California Environmental Protection Agency (Cal-EPA), formerly the California Department of Health Services (DHS). (Canonie, 1996).

Harmon Field is a hundred acre field located at 1494 South Airport Road. The airfield has been in full operation since 1952. The uses of the airport are all agriculturally related. The primary use is for crop duster operations. (Canonie 1996). …

Structure Factors Of Binary Fluids In A Dilute Gel, J.C. Lee

Faculty Publications

The statio and dynamic structure factors of binary fluids in a dilute gel are computed using a two-dimensional kinetic Ising model. The wetting effect of the gel strands is modeled with ''gel atoms'' which are distributed randomly among the spins and impose a field on their neighboring spins, all in the same direction. The result for the static structure factor shows the presence of adsorption clusters which mask the gel atoms. The result for the dynamic Structure factor shows an extremely slow relaxation-at late times which cannot be fitted in the form of the activated dynamic scaling known for random-field …

"A Geological Interpretation Of The Stanley Fault And Other Thrust Faults In Page County, Virginia", Michael James Sarros

OES Theses and Dissertations

Paleozoic carbonate rocks flooring Page Valley (within Page County) are overthrust by Precambrian to Cambrian elastic rocks of the Blue Ridge to the east of the study area. King (1950) recognized that the Cambrian carbonate sequence of Page Valley, near Stanley, Virginia, is broken by a large transverse fault which he named the Stanley fault. King (1950) interpreted the Stanley fault as a high-angle reverse fault with oblique-slip displacement. However, detailed mapping and structural data collected in this study indicate the Stanley fault is a low angle thrust fault which cuts all pre-Alleghanian and Early Alleghanian structures.

Two previously unrecognized …

Heavy-Ion Interaction Models For Radiation Transport, Rajendra R. Dubey

Physics Theses & Dissertations

This dissertation is concerned with finding the values for the nuclear cross sections used in the Boltzmann equation for space radiation transport and dose estimates. An extraordinary number of cross sections are required because of the large number of ion types and their extensive energy range, The Lippmann-Schwinger equation is numerically solved in momentum space for a first order optical potential (free space case) and calculations are made for the total and absorption cross sections for nudeus-nucleus scattering. Absorption cross sections are also calculated using a medium modified firstorder optical potential in the Lippmann-Schwinger equation and are compared with experimental …

A Relativistic Model For Heavy Mesons, Jialin Zeng

Physics Theses & Dissertations

Motivated by the present interest in the heavy quark effective theory, we construct a model for heavy mesons based on a relativistic bound state wave equation, the Gross equation. The kernel we use is based on scalar confining and vector Coulomb potentials. Wave functions are treated to leading order and energies to order 1/_MQ in the heavy-light systems, and to order 1/_M²_Q in heavy-heavy systems. Our results are in good agreement with experimental measurements. This model may be used to study weak decay properties in the framework of the heavy quark effective theory and ultimately to …

A Simple Mathematical-Model And Alternative Paradigm For Certain Chemotherapeutic Regimens, J. A. Adam, J. C. Panetta

Mathematics & Statistics Faculty Publications

A simplified two-compartment model for cell-specific chemotherapy is analysed by reformulating the governing system of differential equations as a Schrodinger equation in time. With the choice of an exponentially decaying function representing the effects of chemotherapy on cycling tumor cells, the potential function V(t) is a Morse-type potential, well known in the quantum mechanical literature; and the solutions are obtainable in terms of confluent hypergeometric functions (or the related Whittaker functions). Because the chemotherapy is administered periodically, the potential V(t) is periodic also, and use is made of existing theory (Floquet theory) as applied to scattering by periodic potentials in …

Analysis Of Growth Curves Under Some Special Covariance Structures, Shobha Prabhala

Mathematics & Statistics Theses & Dissertations

In this dissertation we consider the growth curve or generalized MANOVA model in its most general form given by and develop statistical methodology for analyzing data using this model. Here g represents the number of groups, Y_ij is the observation matrix, ξ is a matrix of unknown parameters, A_i is a known matrix of rank g, and B_ij is a matrix of rank k. Further, the rows of the error matrix ∈_ij are independent and each distributed as N_pij (0, Σ_ij).This model accommodates different kinds of unbalanced data, such as, monotone data, data …

Atomic Broadcast In Heterogeneous Distributed Systems, Osman Zeineldine

Computer Science Theses & Dissertations

Communication services have long been recognized as possessing a dominant effect on both performance and robustness of distributed systems. Distributed applications rely on a multitude of protocols for the support of these services. Of crucial importance are multicast protocols. Reliable multicast protocols enhance the efficiency and robustness of distributed systems. Numerous reliable multicast protocols have been proposed, each differing in the set of assumptions adopted, especially for the communication network. These assumptions make each protocol suitable for a specific environment. The presence of different distributed applications that run on different LANs and single distributed applications that span different LANs mandate …

Copper Complexation Capacity And Copper Speciation In Freshwater Lakes (Lake Western Branch And Lake Prince), Rachide Ibrahimo Abdul Sultana

Chemistry & Biochemistry Theses & Dissertations

This research examines the copper complexation capacity, copper speciation and dissolved copper concentrations in Lake Western Branch (WB) and Lake Prince (LP) both located in Suffolk, Virginia. These lakes are drinking water reservoirs for the cities of Suffolk and Norfolk, and they experience blooms of algae which can deplete them of oxygen and affect treatment of their waters for drinking. Copper sulfate has regularly been added to control the algae, but the effectiveness of these additions is uncertain. For environmental management implications, knowledge of speciation (i.e., the concentrations of the various chemical forms) is important in studying the effects of …

Text Independent Speaker Verification Using Binary-Pair Partitioned Neural Networks, Claude A. Norton Iii

Electrical & Computer Engineering Theses & Dissertations

A method is presented for the application of binary-pair partitioned neural networks to the task of speaker verification. This technique is based on a previously developed neural network classifier for speaker identification.

The main focus of this research was the development and testing of the algorithms necessary to extend the binary-pair partitioning approach from speaker identification to speaker verification. The method is based on the development of a user profile which is obtained from discriminative data provided by the binary-pair partitioned neural networks.

Experimental results are provided which demonstrate the viability of this approach, using the TIMIT speech corpus for …

Whaling Dispute Continues, Andrew Dizon, Phillip Clapham, William Perrin, Robert L. Brownell Jr.

United States Department of Commerce: Staff Publications

Apparently alarmed that an advertisement in Nature referencing the study of Baker and Palumbi (Science 265, 1538; 1994) might lend undeserved credence to the notion that illegal whale products find their way into Japanese markets, Milton Freeman (Nature 376, 11; 1995) reiterates the arguments of the Fisheries Agency of Japan (FAJ) that the study is fundamentally flawed. As Freeman's letter contains several serious errors, we feel obliged to comment.

Final Report Biological Monitoring Of The Hollywood-Hallandale Beach Renourishment, Richard Dodge, Walter Goldberg, Charles Messing, Steven C. Hess

Marine & Environmental Sciences Faculty Reports

A four-year study was undertaken to survey Broward County, Florida (southeast Florida) coral communities and infaunal marine biota in relation to possible effects from the Hollywood- Hallandale Beach renourishment project. Beach restoration involves dredging sand from offshore deposits and placing it on eroded beaches, activities which may cause sedimentation and turbidity. Coral reefs were assessed using transect and quadrat surveys at a total of 15 stations, unevenly distributed between dredging impact (n=9) and control (n=6) areas to characterize and quantify populations of sponges, gorgonians, scleractinian corals, as well as other less well represented groups. In addition, the infauna of sand …

Disorder And Synchronization In A Josephson Junction Plaquette, Adam S. Landsberg, Yuri Braiman, Kurt Wiesenfeld

WM Keck Science Faculty Papers

We describe the effects of disorder on the coherence properties of a 2 x 2 array of Josephson junctions (a "plaquette"). The disorder is introduced through variations in the junction characteristics. We show that the array will remain one-to-one frequency locked despite large amounts of the disorder, and determine analytically the maximum disorder that can be tolerated before a transition to a desynchronized state occurs. Connections with larger N x M arrays are also drawn.

A Provably Convergent Dynamic Training Method For Multi-Layer Perceptron Networks, Timothy L. Andersen, Tony R. Martinez

Faculty Publications

This paper presents a new method for training multi-layer perceptron networks called DMP1 (Dynamic Multilayer Perceptron 1). The method is based upon a divide and conquer approach which builds networks in the form of binary trees, dynamically allocating nodes and layers as needed. The individual nodes of the network are trained using a genetic algorithm. The method is capable of handling real-valued inputs and a proof is given concerning its convergence properties of the basic model. Simulation results show that DMP1 performs favorably in comparison with other learning algorithms.

Connectionist Models For Certain Tasks Related To Object Recognition., Jayanta Basak Dr.

Doctoral Theses

Recognition of objects in an image, according to Suetens et al. [1), relers to the task of finding and labeling parts of a two-dimensional image of a scene that correspond to the real objects in the scene. Object recognition is necessary in a variety of domains like robot navigation, aerial imagery analysis, industrial inspection and so on. Normally, different strategies for object recognition (1-(5] involve establishing some model for each object, i.e., some general description of each object, and then labeling different parts of the scene according to the knowledge about the models.Object models can have two-dimensional (2D) or three-climensional …

The Phase Diagram Of Crystalline Surfaces, Simon Catterall, Konstantinos N. Anagnostopoulos, Mark Bowick, Marco Falcioni, G. Thorleifsson

Physics - All Scholarship

We report the status of a high-statistics Monte Carlo simulation of non-self-avoiding crystalline surfaces with extrinsic curvature on lattices of size up to 128^2 nodes. We impose free boundary conditions. The free energy is a gaussian spring tethering potential together with a normal-normal bending energy. Particular emphasis is given to the behavior of the model in the cold phase where we measure the decay of the normal-normal correlation function.

Diel Variations Of H2o2 In Greenland: A Discussion Of The Cause And Effect Relationship, R Bales, Joe Mcconnell, Mark V. Losleben, Martha H. Conklin, Katrin Fuhrer, Albrecht Neftel, Jack E. Dibb, D W. Kahl, C Stearns

Earth Sciences

Atmospheric hydrogen peroxide (H₂O₂) measurements at Summit, Greenland, in May–June, 1993 exhibited a diel variation, with afternoon highs typically 1–2 parts per billion by volume (ppbv) and nighttime lows about 0.5 ppbv lower. This variation closely followed that for temperature; specific humidity exhibited the same general trend. During a 17-day snowfall-free period, surface snow was accumulating H₂O₂, apparently from nighttime cocondensation of H₂O and H₂O₂. Previous photochemical modeling (Neftel et al., 1995) suggests that daytime H₂O₂ should be about 1 ppbv, significantly lower …

Magnetic-Field-Induced Griffiths Phase Versus Random-Field Criticality And Domain Wall Susceptibility Of Fe0.47zn0.53f2, Christian Binek, S. Kuttler, Wolfgang Kleemann

Christian Binek Publications

The well-known peak of the parallel ac susceptibility arising below TN in Fe_0.47Zn_0.53F₂ splits into a narrow critical peak at T_c (H) and a broad field-induced Griffiths phase shoulder peaking at T_p>T_c(H) in magnetic fields H≳1.6 MA /m. Random-field (RF) criticality with α̃≈0 and subsequent rounding due to RF trapping of thermal fluctuations are observed upon zero-field cooling as T→T_c^-(H). The frozen domain state obtained after rapid field cooling reveals excess susceptibility Δχw′∝H^2.6, owing to rough walls with thermally activated stiffness.

Control Of Bright Picosecond X-Ray Emission From Intense Subpicosecond Laser-Plasma Interactions, J. Workman, Anatoly Maksimchuk, X. Liu, U. Ellenberger, J.S. Coe, C.-Y. Chien, Donald P. Umstadter

Donald Umstadter Publications

Using temporally and spectrally resolved diagnostics, we show that the pulse duration of laser-produced soft x rays emitted from solid targets can be controlled, permitting a reduction to as short as a few picoseconds. To enable this control, only a single parameter must be adjusted, namely, the intensity of the high-contrast ultrashort laser pulse (400 fs). These results are found to be in qualitative agreement with a simple model of radiation from a collisionally dominated atomic system.

The Aftermath Of Kansas V. Colorado: Regulation Of Well Pumping In The Arkansas Valley, Hal Simpson, David L. Harrison, Michael T. Mitchell, Steve Arveschoug, University Of Colorado Boulder. Natural Resources Law Center

The Aftermath of Kansas v. Colorado: Regulation of Well Pumping in the Arkansas Valley (September 18)

27 pages.

Contents:

Draft rules and regulations governing the use, control, and protection of surface and ground water rights in the Arkansas River and its tributaries : revised draft, September 6, 1995 / Hal Simpson -- Lower Arkansas Water Management Association viewpoint / David L. Harrison -- Aftermath of Kansas v. Colorado : concerns of surface users / Michael T. Mitchell -- Aftermath of Kansas vs. Colorado : role of the Southeastern Colorado Water Conservancy District / Steve Arveschoug

On May 15, 1995 the Supreme Court handed down its opinion in the case of Kansas v. Colorado, 1995 WL 283477 …

Three-Phase Intersection Points In Monolayers, John P. Hagen, Harden M. Mcconnell

Chemistry and Biochemistry

Some phospholipid/dihydrocholesterol Langmuir monolayers form coexisting liquid phases. Gas domains form at the interface between the phospholipid-rich and dihydrocholesterol-rich liquid phases when these monolayers undergo expansion to low surface pressure. Analysis of the domain shapes thus formed yields the relative line tensions of the gas/phospholipid, gas/dihydrocholesterol, and phospholipid/dihydrocholesterol phase interfaces.

Interfaces For Disk-Directed I/O, David Kotz

Computer Science Technical Reports

In other papers I propose the idea of disk-directed I/O for multiprocessor file systems. Those papers focus on the performance advantages and capabilities of disk-directed I/O, but say little about the application-programmer's interface or about the interface between the compute processors and I/O processors. In this short note I discuss the requirements for these interfaces, and look at many existing interfaces for parallel file systems. I conclude that many of the existing interfaces could be adapted for use in a disk-directed I/O system.

Structured Permuting In Place On Parallel Disk Systems, Leonard F. Wisniewski

Computer Science Technical Reports

The ability to perform permutations of large data sets in place reduces the amount of necessary available disk storage. The simplest way to perform a permutation often is to read the records of a data set from a source portion of data storage, permute them in memory, and write them to a separate target portion of the same size. It can be quite expensive, however, to provide disk storage that is twice the size of very large data sets. Permuting in place reduces the expense by using only a small amount of extra disk storage beyond the size of the …