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2003

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Articles 1681 - 1710 of 3876

Full-Text Articles in Physical Sciences and Mathematics

Be-10/Be-7 Tracer Of Atmospheric Transport And Stratosphere-Troposphere Exchange, C. Jordan, Jack E. Dibb, R C. Finkel Apr 2003

Be-10/Be-7 Tracer Of Atmospheric Transport And Stratosphere-Troposphere Exchange, C. Jordan, Jack E. Dibb, R C. Finkel

Earth Sciences

The 10Be/7Be ratio is a sensitive tracer of atmospheric transport and stratosphere-troposphere exchange (STE). Data from five NASA aircraft field missions (PEM: West A and B, Tropics A; SONEX; and SUCCESS) have been assembled to produce the largest data set of 10Be,7Be, and their ratio collected to date (>300 samples). Ratios near 0.60 are indicative of tropospheric air with little stratospheric influence, while higher ratios are found in stratospheric air. Samples from the lower stratosphere were all collected within 2.5 km of the tropopause and had ratios >1.27. Of these lower stratosphere samples …


Effect Of Petrochemical Industrial Emissions Of Reactive Alkenes And NoX On Tropospheric Ozone Formation In Houston, Texas, T. B. Ryerson, M. Trainer, W. M. Angevine, C. A. Brock, R. W. Dissly, F. C. Fehsenfeld, G. J. Frost, P. D. Goldan, J. S. Holloway, G. Hübler, R. O. Jakoubek, W. C. Kuster, J. A. Neuman, D. K. Nicks, D. D. Parrish, J. M. Roberts, D. T. Sueper, E. L. Atlas, Stephen G. Donnelly Ph.D., F. Flocke, A. Fried, W. T. Potter, S. Schauffler, V. Stroud, A. J. Weinheimer, B. P. Wert, C. Wiedinmyer, R. J. Alvarez, R. M. Banta, L. S. Darby, C. J. Senff Apr 2003

Effect Of Petrochemical Industrial Emissions Of Reactive Alkenes And NoX On Tropospheric Ozone Formation In Houston, Texas, T. B. Ryerson, M. Trainer, W. M. Angevine, C. A. Brock, R. W. Dissly, F. C. Fehsenfeld, G. J. Frost, P. D. Goldan, J. S. Holloway, G. Hübler, R. O. Jakoubek, W. C. Kuster, J. A. Neuman, D. K. Nicks, D. D. Parrish, J. M. Roberts, D. T. Sueper, E. L. Atlas, Stephen G. Donnelly Ph.D., F. Flocke, A. Fried, W. T. Potter, S. Schauffler, V. Stroud, A. J. Weinheimer, B. P. Wert, C. Wiedinmyer, R. J. Alvarez, R. M. Banta, L. S. Darby, C. J. Senff

Chemistry Faculty Publications

Petrochemical industrial facilities can emit large amounts of highly reactive hydrocarbons and NOx to the atmosphere; in the summertime, such colocated emissions are shown to consistently result in rapid and efficient ozone (O3) formation downwind. Airborne measurements show initial hydrocarbon reactivity in petrochemical source plumes in the Houston, TX, metropolitan area is primarily due to routine emissions of the alkenes propene and ethene. Reported emissions of these highly reactive compounds are substantially lower than emissions inferred from measurements in the plumes from these sources. Net O3 formation rates and yields per NOx molecule oxidized in these petrochemical industrial source plumes …


Constrained Boundary Monitoring For Group Sequential Clinical Trials, Bart E. Burington, Scott S. Emerson Apr 2003

Constrained Boundary Monitoring For Group Sequential Clinical Trials, Bart E. Burington, Scott S. Emerson

UW Biostatistics Working Paper Series

Group sequential stopping rules are often used during the conduct of clinical trials in order to attain more ethical treatment of patients and to better address efficiency concerns. Because the use of such stopping rules materially affects the frequentist operating characteristics of the hypothesis test, it is necessary to choose an appropriate stopping rule during the planning of the study. It is often the case, however, that the number and timing of interim analyses are not precisely known at the time of trial design, and thus the implementation of a particular stopping rule must allow for flexible determination of the …


Hashtables For Real-Time And Embedded Systems, Anand Krishnan Apr 2003

Hashtables For Real-Time And Embedded Systems, Anand Krishnan

All Computer Science and Engineering Research

Real-time are beginning to appear in advanced, high-level programming languages such as Java. When complemented by a real-time operating system, the Real-Time Specification for Java (RTSJ) offers strong execution constraints for applications developed in Java. While the RTSJ make the basic services of Java such as storage and thread management ready for many real-time applications, the collection objects, and the rest of the application run-time library, cannot be used by RTSJ applications until their run-time properties are examined and modified as necessary to make them suitable for use by real-time applications. In this work, we examine the Hashtable collection facility …


Dynamic Assignment Of Scoped Memory Regions In The Translation Of Java To Real-Time Java, Morgan G. Deters Apr 2003

Dynamic Assignment Of Scoped Memory Regions In The Translation Of Java To Real-Time Java, Morgan G. Deters

All Computer Science and Engineering Research

Advances in middleware, operating systems, and popular, general-purpose languages have brought the ideal of reasonably-bound execution time closer to developers who need such assurances for real-time and embedded systems applications. Extensions to the Java libraries and virtual machine have been proposed in a real-time Java standard, which provides for specification of release times, execution costs, and deadlines for a restricted class of threads. To use such features, the programmer is required to use unwieldy code constructs to create region-like areas of storage, associate them with execution scopes, and allocate objects from them. Further, the developer must ensure that they do …


115th Session Iowa Academy Of Science Awards Luncheon, April 25, 2003, Iowa Academy Of Science Apr 2003

115th Session Iowa Academy Of Science Awards Luncheon, April 25, 2003, Iowa Academy Of Science

Iowa Academy of Science Documents

Program:

--- Introductions - Raymond Anderson, President
--- Recognition of students participating in various statewide activities - Ernie Schiller, Chair, Student Programs Committee
--- Presentation of scholarship winners and 2004 AJAS representatives - Ernie Schiller, Chair, Student Programs Committee
--- Presentation of Excellence in Science Teaching Awards - Jeff Weld, Director, ESTA Program


Ua1b3 Technology Advisory Committee Meeting Minutes, Western Kentucky University Apr 2003

Ua1b3 Technology Advisory Committee Meeting Minutes, Western Kentucky University

WKU Archives Records

Meeting regarding the Technical Advisory Committee composition, survey results and improvements to educational technology.


Integrated Coverage And Connectivity Configuration In Wireless Sensor Networks, Xiaorui Wang, Guoliang Xing, Yuanfang Zhang, Chenyang Lu, Robert Pless, Christopher Gill Apr 2003

Integrated Coverage And Connectivity Configuration In Wireless Sensor Networks, Xiaorui Wang, Guoliang Xing, Yuanfang Zhang, Chenyang Lu, Robert Pless, Christopher Gill

All Computer Science and Engineering Research

An effective approach for energy conservation in wireless sensor networks is scheduling sleep intervals for extraneous nodes, while the remaining nodes stay active to provide continuous service. For the sensor network to operate successfully, the active nodes must maintain both sensing coverage and network connectivity. Furthermore, the network must be able to configure itself to any feasible degrees of coverage and connectivity in order to support different applications and environments with diverse requirements. This paper presents the design and analysis of novel protocols that can dynamically configure a network to achieve guaranteed degrees of coverage and connectivity. This work differs …


Amount And Economic Valuation Of Feral Hog Damage To A Unique Basin Marsh Wetland In Florida, Richard M. Engeman, Henry T. Smith, Robert G. Severson, Mary Ann M. Severson, Stephanie A. Shwiff, Bernice Constantin, Daniel Griffen Apr 2003

Amount And Economic Valuation Of Feral Hog Damage To A Unique Basin Marsh Wetland In Florida, Richard M. Engeman, Henry T. Smith, Robert G. Severson, Mary Ann M. Severson, Stephanie A. Shwiff, Bernice Constantin, Daniel Griffen

United States Department of Agriculture Wildlife Services: Staff Publications

Feral hogs (Sus scrofa) have been introduced into many natural habitats throughout the world, and they have adversely affected the environment in most of those places. Basin marshes are unique, but dwindling ecosystems in Florida that are especially vulnerable to damage by feral hogs. We estimated the amount of hog damage to the last remnant of a basin marsh system in Savannas Preserve State Park (SPSP), and to ecotones within the marsh. We also applied an economic valuation method for the hog damage that was based on the dollar amounts that wetland regulators have allowed permit applicants to …


P-Fastus: Information Extraction System Implemented In A Constraint Programming Language -Sicstus Prolog, Rajen Subba '03 Apr 2003

P-Fastus: Information Extraction System Implemented In A Constraint Programming Language -Sicstus Prolog, Rajen Subba '03

Honors Projects

P-FASTUS is an Information Extraction system developed in SICStus Prolog based on the implementation of FASTUS. It is program that extracts prespecified information such as the name of the companny, location and the position being advertised from" Job PostingIs'' in text files. The system is composed of different levels of processing phases that are implemented using finite-state transducers.


Optically Oriented And Detected Electron Spin Resonance In A Lightly Doped N-Gaas Layer, John S. Colton, T. A. Kennedy, A. S. Bracker, D. Gammon, J. B. Miller Apr 2003

Optically Oriented And Detected Electron Spin Resonance In A Lightly Doped N-Gaas Layer, John S. Colton, T. A. Kennedy, A. S. Bracker, D. Gammon, J. B. Miller

Faculty Publications

Spin resonance of localized electrons bound to donors in a specially designed n-GaAs layer has been performed at 236 MHz and 41 mT, using circular polarized light to polarize the electrons and photoluminescence to detect the electronic polarization. The polarization was diminished under the resonance condition. The electronic g factor obtained by this measurement is - 0.41 ± 0.01. The resonance linewidth of 2 mT corresponds to a spin lifetime of 28 ns. In order to observe the electronic spin resonance, nuclear effects were eliminated by application of rf fields to simultaneously resonate the nuclear spins.


Multiflow Tcp, Udp, Ip, And Atm Traffic Generation Module, Eliot I. Sinclair, John W. Lockwood Apr 2003

Multiflow Tcp, Udp, Ip, And Atm Traffic Generation Module, Eliot I. Sinclair, John W. Lockwood

All Computer Science and Engineering Research

Networking devices must be capable of processing traffic flows from multiple sources. In order to verify that such devices operates properly, a network testbench can be used to inject traffic into the device. The specification of the traffic flows can be difficult. At the low level, there are header fields, data checksums, and packet length fields that all must be formatted correctly. Further, there can be multiple flows of traffic that will arrive simultaneously. It is desirable to specify traffic at a high level of abstraction. A software program can then be written to parse the specification and generate the …


Bv Photometry Of Ux Ari In The Period 1987–2002, Vidar Aarum Ulvås, Gregory W. Henry Apr 2003

Bv Photometry Of Ux Ari In The Period 1987–2002, Vidar Aarum Ulvås, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We present 14.3 years of previously unpublished photometric observations of UX Ari. The observations were obtained between 1987.9 and 2002.2 using the T3 0.4-metre Automatic Photoelectric Telescope at Fairborn Observatory and consist of 1228 B band and 1213 V band measurements. The comparison star was 62 Ari. We have analyzed the new data together with previously published photometric observations. The V magnitude shows variations with dominant periods of about 12 and 25 years, where the longest period seems to correspond to an activity cycle. The previously reported anticorrelation between the colour and V magnitude variations is confirmed.


The Online Median Problem, Ramgopal R. Mettu, C. Greg Plaxton Apr 2003

The Online Median Problem, Ramgopal R. Mettu, C. Greg Plaxton

Dartmouth Scholarship

We introduce a natural variant of the (metric uncapacitated) k-median problem that we call the online median problem. Whereas the k-median problem involves optimizing the simultaneous placement of k facilities, the online median problem imposes the following additional constraints: the facilities are placed one at a time, a facility cannot be moved once it is placed, and the total number of facilities to be placed, k, is not known in advance. The objective of an online median algorithm is to minimize the competitive ratio, that is, the worst-case ratio of the cost of an online placement to …


Local Rings Of Bounded Cohen-Macaulay Type, Graham J. Leuschke, Roger Wiegand Apr 2003

Local Rings Of Bounded Cohen-Macaulay Type, Graham J. Leuschke, Roger Wiegand

Mathematics - All Scholarship

Let (R,m,k) be a local Cohen-Macaulay (CM) ring of dimension one. It is known that R has finite CM type if and only if R is reduced and has bounded CM type. Here we study the one-dimensional rings of bounded but infinite CM type. We will classify these rings up to analytic isomorphism (under the additional hypothesis that the ring contains an infinite field). In the first section we deal with the complete case, and in the second we show that bounded CM type ascends to and descends from the completion. In the third section we study ascent and descent …


Hypersurfaces Of Bounded Cohen-Macaulay Type, Graham J. Leuschke, Roger Wiegand Apr 2003

Hypersurfaces Of Bounded Cohen-Macaulay Type, Graham J. Leuschke, Roger Wiegand

Mathematics - All Scholarship

Let R = k[[x0, . . . , xd]]/(f), where k is a field and f is a non-zero non-unit of the formal power series ring k[[x0, . . . , xd]]. We investigate the question of which rings of this form have bounded Cohen–Macaulay type, that is, have a bound on the multiplicities of the indecomposable maximal Cohen–Macaulaymodules. As with finite Cohen–Macaulay type, if the characteristic is different from two, the question reduces to the one-dimensional case: The ring R has bounded Cohen–Macaulay type if and only if R ∼= k …


System-On-Chip Packet Processor For An Experimental Network Services Platform, David Taylor, Alex Chandra, Yuhua Chen, Sarang Dharmapurikar, John Lockwood, Wenjing Tang, Jonathan Turner Apr 2003

System-On-Chip Packet Processor For An Experimental Network Services Platform, David Taylor, Alex Chandra, Yuhua Chen, Sarang Dharmapurikar, John Lockwood, Wenjing Tang, Jonathan Turner

All Computer Science and Engineering Research

As the focus of networking research shifts from raw performance to the delivery of advanced network services, there is a growing need for open-platform systems for extensible networking research. The Applied Research Laboratory at Washington University in Saint Louis has developed a flexible Network Services Platform (NSP) to meet this need. The NSP provides an extensible platform for prototyping next-generation network services and applications. This paper describes the design of a system-on-chip Packet Processor for the NSP which performs all core packet processing functions including segmentation and reassembly, packet classification, route lookup, and queue management. Targeted to a commercial configurable …


Three-Dimensional Quantitative Structure−Property Relationship (3d-Qspr) Models For Prediction Of Thermodynamic Properties Of Polychlorinated Biphenyls (Pcbs): Enthalpies Of Fusion And Their Application To Estimates Of Enthalpies Of Sublimation And Aqueous Solubilities, Swati Puri, James S. Chickos, William J. Welsh Apr 2003

Three-Dimensional Quantitative Structure−Property Relationship (3d-Qspr) Models For Prediction Of Thermodynamic Properties Of Polychlorinated Biphenyls (Pcbs): Enthalpies Of Fusion And Their Application To Estimates Of Enthalpies Of Sublimation And Aqueous Solubilities, Swati Puri, James S. Chickos, William J. Welsh

James Chickos

No abstract provided.


Comparison Of Features From Sar And Gmti Imagery Of Ground Targets, David Beckman, Samuel J. Frame Apr 2003

Comparison Of Features From Sar And Gmti Imagery Of Ground Targets, David Beckman, Samuel J. Frame

Statistics

We describe an algorithm for class-independent automated target recognition (ATR) and association using range-Doppler images of moving targets and SAR images of stationary targets. This algorithm can be used both for target identification (by comparison against a pre-existing database of measurements of all potential targets) and target association (not requiring a pre-existing database). The algorithm computes a one-dimensional signature for each received range-Doppler image; these signatures are stored in a database for comparison against other detections. The signatures used in our algorithm are range profiles, generated from the clutter-suppressed, filtered image by incoherently integrating the image energy across a number …


Lake Whatcom Monitoring Project 2001/2002 Report, Robin A. Matthews, Michael Hilles, Joan Vandersypen, Robert J. Mitchell, Geoffrey B. Matthews Apr 2003

Lake Whatcom Monitoring Project 2001/2002 Report, Robin A. Matthews, Michael Hilles, Joan Vandersypen, Robert J. Mitchell, Geoffrey B. Matthews

Lake Whatcom Annual Reports

This report is part of an on-going series of annual reports and special project reports that document the Lake Whatcom monitoring program. This work is conducted by the Institute for Watershed Studies and other departments at Western Washington University.

The major objective of this program is to provide long-term baseline water quality monitoring in Lake Whatcom and selected tributaries. Each section contains brief explanations about the water quality data, along with discussions of patterns observed in Lake Whatcom.


Protecting Sensitive Credential Content During Trust Negotiation, Ryan D. Jarvis Apr 2003

Protecting Sensitive Credential Content During Trust Negotiation, Ryan D. Jarvis

Theses and Dissertations

Keeping sensitive information private in a public world is a common concern to users of digital credentials. A digital credential may contain sensitive attributes certifying characteristics about its owner. X.509v3, the most widely used certificate standard, includes support for certificate extensions that make it possible to bind multiple attributes to a public key contained in the certificate. This feature, although convenient, potentially exploits the certificate holder's private information contained in the certificate. There are currently no privacy considerations in place to protect the disclosure of attributes in a certificate. This thesis focuses on protecting sensitive credential content during trust negotiation …


An Extended Burst Tail From Sgr 1900+14 With A Thermal X-Ray Spectrum, Geoffrey T. Lenters, Peter M. Woods, Johnathan E. Goupell, Chryssa Kouveliotou Apr 2003

An Extended Burst Tail From Sgr 1900+14 With A Thermal X-Ray Spectrum, Geoffrey T. Lenters, Peter M. Woods, Johnathan E. Goupell, Chryssa Kouveliotou

University Faculty Publications and Creative Works

The soft gamma repeater SGR 1900+14 entered a new phase of activity in 2001 April initiated by the intermediate flare recorded on April 18. Ten days following this flare, we discovered an abrupt increase in the source flux between consecutive Rossi X-Ray Timing Explorer (RXTE) orbits. This X-ray flux excess decayed over the next several minutes and was subsequently linked to a high fluence burst from SGR 1900+14 recorded by other spacecraft (Ulysses and Wind/Konus) while the SGR was Earth-occulted for RXTE. We present here spectral and temporal analysis of both the burst of April 28 and the long X-ray …


2003 - The Eighth Annual Symposium Of Student Scholars Apr 2003

2003 - The Eighth Annual Symposium Of Student Scholars

Symposium of Student Scholars Program Books

The full program book from the Eighth Annual Symposium of Student Scholars, held on April 18, 2003. Includes abstracts from the presentations and posters.


The Scalar Sector And The Eta -> 3 Pi Problem, Joseph Schechter, Abdou Abdel-Rehim, Deirdre Black, Amir H. Fariborz Apr 2003

The Scalar Sector And The Eta -> 3 Pi Problem, Joseph Schechter, Abdou Abdel-Rehim, Deirdre Black, Amir H. Fariborz

Physics - All Scholarship

First, recent work on light scalar mesons, which is of possible interest in connection with the strong coupling region of QCD is briefly discussed. Then a very short highlighting of a paper concerned with an application to the eta -> 3 pi problem is presented.


A Thesis On A 3d Input Device For Sketching Characters, Mark A. Schroering Apr 2003

A Thesis On A 3d Input Device For Sketching Characters, Mark A. Schroering

All Computer Science and Engineering Research

The goal of this project is to develop a 3D input device using a stiff piece of paper and a camera. The camera tracks the piece of paper in 3D space. The user orients the paper in 3D space and then draws on the paper using a pen-like device. The camera tracks the movement of the pen on the piece of paper. The location of the pen in 3D space can then be calculated from the orientation of the paper. A drawing application that uses this 3D input device was also developed. The application allows a user to make characters …


Simulating The Doppler-Free Fluorescence Spectrum For The Potassium D1 Transitions, Paul G. Johnson, Marc R. Hammond, Vincent B. Wickwar Apr 2003

Simulating The Doppler-Free Fluorescence Spectrum For The Potassium D1 Transitions, Paul G. Johnson, Marc R. Hammond, Vincent B. Wickwar

Posters

Radiation theory (absorption, spontaneous emission, and stimulated emission) is applied to Potassium (39K and 41K) to examine details of the D1 lines, Figure 1, in the near IR at 770 nm. When examining the resonance fluorescence from two counter-propagation laser beams in a K cell, Figure 2, three prominent “Doppler-free” features—dips at the D1a and D1b resonances and spikes at their crossover frequencies—stand out superposed on the fluorescence background. They are examined with a detailed simulation, Figures 3 and 4, and compared to observations, Figure 5. Parametric studies of the Doppler-free features, Figures 6–8, indicate how to maximize their prominence, …


Prediction Of Saturation Effects On Potassium Lidar Returns, Joel R. Drake, Vincent B. Wickwar Apr 2003

Prediction Of Saturation Effects On Potassium Lidar Returns, Joel R. Drake, Vincent B. Wickwar

Posters

The Atmospheric Lidar Observatory, on the Utah State University campus, will add a potassium lidar to its existing Rayleigh scatter system in the near future. The current system accurately measures temperatures from 40 km to 85 km in altitude.

Beginning at 80 km, a potassium layer forms due to the disintegration of meteors as they enter earth’s atmosphere. ALO plans to probe this layer using an alexandrite laser scanning a wavelength region near 770 nm, where potassium absorbs light. When the light is re-emitted, it can be measured in the same manner as scattered light in a Rayleigh lidar.

Usually, …


Age-Specific Reproduction By Female Laughing Gulls (Larus Atricilla), Richard A. Dolbeer, Glen E. Bernhardt Apr 2003

Age-Specific Reproduction By Female Laughing Gulls (Larus Atricilla), Richard A. Dolbeer, Glen E. Bernhardt

United States Department of Agriculture Wildlife Services: Staff Publications

The age at which female gulls first reproduce is poorly documented. We examined plumage and reproductive organs of Laughing Gulls (Larus atricilla) collected from May–August 2000–2001 at John F. Kennedy International Airport, New York, to determine age-specific reproductive effort. Each gull was classified as one year old (hatched in previous year), two years old, or ≥3 years old on the basis of color patterns of the hood and tail feathers and fifth primary flight feather. For females, each ovary was examined to determine if postovulatory follicles were present. In 2000 and 2001, the first gulls with postovulatory follicles were recorded …


Newtonian Cosmology, Ronald Lovett Apr 2003

Newtonian Cosmology, Ronald Lovett

Topics in Quantum Mechanics

No abstract provided.


Preparation Of 2s,3s-N-Isobutyl-N-(2-Hydroxy-3-Amino-4-Phenylbutyl)-P-Nitrobenzenesulfonylamide Hydrochloride And Other Derivatives Of 2-Hydroxy-1,3-Diamines, Aslam A. Malik, Hasan Palandoken, Joy A. Stringer, Roland P. Carlson, John Leach, Thomas G. Archibald, Robert G. Miotke Apr 2003

Preparation Of 2s,3s-N-Isobutyl-N-(2-Hydroxy-3-Amino-4-Phenylbutyl)-P-Nitrobenzenesulfonylamide Hydrochloride And Other Derivatives Of 2-Hydroxy-1,3-Diamines, Aslam A. Malik, Hasan Palandoken, Joy A. Stringer, Roland P. Carlson, John Leach, Thomas G. Archibald, Robert G. Miotke

Chemistry and Biochemistry

The present invention provides a new process for the preparation of 2S,3S-N-isobutyl-N-(2-hydroxy-3-amino-4phenylbutyl)- p-nitrobenzenesulfonylamide hydrochloride, wherein this compound is prepared directly from the chloromethylalcohol. Importantly, the process of the present invention results in higher yields of 2S,3S-N-isobutyl-N-(2hydroxy -3 -amino -4-phenylbutyl) -pnitrobenzenesulfonylamide hydrochloride without sacrificing its purity. The processes of the present inventin can be used to prepare not only the 2S,3S-derivative, but also the 2R,3S-, 2S,2R- and the 2R,3R-derivatives.