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1998

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Articles 271 - 300 of 2574

Full-Text Articles in Physical Sciences and Mathematics

Finding Cyclic Redundancy Check Polynomials For Multilevel Systems, James A. Davis, Miranda Mowbray, Simon Crouch Oct 1998

Finding Cyclic Redundancy Check Polynomials For Multilevel Systems, James A. Davis, Miranda Mowbray, Simon Crouch

Department of Math & Statistics Faculty Publications

This letter describes a technique for finding cyclic redundancy check polynomials for systems for transmission over symmetric channels which encode information in multiple voltage levels, so that the resulting redundancy check gives good error protection and is efficient to implement. The codes which we construct have a Hamming distance of 3 or 4. We discuss a way to reduce burst error in parallel transmissions and some tricks for efficient implementation of the shift register for these polynomials. We illustrate our techniques by discussing a particular example where the number of levels is 9, but they are applicable in general.

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Magnetic Control Of Convection In Nonconducting Diamagnetic Fluids, J. Huang, D. D. Gray, Boyd F. Edwards Oct 1998

Magnetic Control Of Convection In Nonconducting Diamagnetic Fluids, J. Huang, D. D. Gray, Boyd F. Edwards

All Physics Faculty Publications

Inhomogeneous magnetic fields exert a body force on electrically nonconducting, diamagnetic fluids. This force can be used to compensate for gravity and to control convection. The field effect on convection is represented by a dimensionless vector parameter Rm=(μ0αχ0d3ΔT/ρ0νDT)(H⋅∇H)r=0ext, which measures the relative strength of the induced magnetic buoyancy force due to the applied field gradient. The vertical component of this parameter competes with the gravitational buoyancy effect and a critical relationship between this component and the Rayleigh number is identified for the onset of convection. …

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Analysis Of The Interpolation Error Between Multiresolution Images, Bryan S. Morse Oct 1998

Analysis Of The Interpolation Error Between Multiresolution Images, Bryan S. Morse

Faculty Publications

Many rendering or image-analysis systems require calculation of versions of an image at lesser resolutions than the original. Because the filtering required to perform such calculations accurately cannot typically be done in real time, many systems use interpolation between images at precalculated resolutions. This discrete sampling of the scale component of multiresolution image spaces is analogous to spatial sampling in discrete images. This paper quantifies and bounds the error that can be introduced during such interpolation as a function of the scale-space sampling rate used. A method is presented that uses the diffusion equation to relate spatial derivatives to scale …

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The Development And Characterisation Of A Red-Sensitised Photopolymer Holographic Recording Material, Clodagh Feely Oct 1998

The Development And Characterisation Of A Red-Sensitised Photopolymer Holographic Recording Material, Clodagh Feely

Doctoral

The development and characterisation of a photopolymerisable photopolymer holographic recording material, for red sensitisation is described. The material comprises dye (methylene blue), an electron donor (triethanolamine) and monomer (acrylamide and methylene-bis-acrylamide). A binder is also included (poly(vinylalcohol) to allow recording in dry layer format. One of the main advantages of the material is its ability to self-develop, which makes it highly suitable for a range of applications which includes the fabrication of Holographic Optical Elements (HOEs). The optimisation of the material formula for red-sensitisation using holographic techniques is described. Diffraction efficiencies of over 70% were obtained in 25 seconds with …

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กิจกรรมสิ่งแวดล้อม Oct 1998

กิจกรรมสิ่งแวดล้อม

Thai Environment

No abstract provided.

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สรุปข่าวสิ่งแวดล้อม : กรกฎาคม-กันยายน 2541 Oct 1998

สรุปข่าวสิ่งแวดล้อม : กรกฎาคม-กันยายน 2541

Thai Environment

No abstract provided.

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สัมภาษณ์ : รศ. วราพรรณ ด่านอุตร : แนวทางการจัดการสารเคมีอย่างปลอดภัยในห้องปฏิบัติการ, กองบรรณาธการ Oct 1998

สัมภาษณ์ : รศ. วราพรรณ ด่านอุตร : แนวทางการจัดการสารเคมีอย่างปลอดภัยในห้องปฏิบัติการ, กองบรรณาธการ

Thai Environment

No abstract provided.

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ปรอทในก๊าซธรรมชาติ, มารยาท วีรกรม Oct 1998

ปรอทในก๊าซธรรมชาติ, มารยาท วีรกรม

Thai Environment

No abstract provided.

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ความสำคัญของคุณภาพน้ำต่อทรัพยากรสัตว์น้ำจืด ในอ่างเก็บน้ำลำตะคอง จังหวัดนครราชสีมา, เดชาพล รุกขมธุร์ Oct 1998

ความสำคัญของคุณภาพน้ำต่อทรัพยากรสัตว์น้ำจืด ในอ่างเก็บน้ำลำตะคอง จังหวัดนครราชสีมา, เดชาพล รุกขมธุร์

Thai Environment

No abstract provided.

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ผลกระทบของพายุไต้ฝุนนลินดาในอ่าวไทยและบริเวณชายฝั่ง, กัลยา สุนทรวงศ์สกุล, ทวีศักดิ์ ปิยะกาญจน์ Oct 1998

ผลกระทบของพายุไต้ฝุนนลินดาในอ่าวไทยและบริเวณชายฝั่ง, กัลยา สุนทรวงศ์สกุล, ทวีศักดิ์ ปิยะกาญจน์

Thai Environment

No abstract provided.

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โครงการติดตามคุณ่ภาพน้ำบริเวณอ่าวสัตหีบ (Sattahlp Water Quality Monitoring Program), สมมาตร์ เนียมนิล Oct 1998

โครงการติดตามคุณ่ภาพน้ำบริเวณอ่าวสัตหีบ (Sattahlp Water Quality Monitoring Program), สมมาตร์ เนียมนิล

Thai Environment

No abstract provided.

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มาตรการป้องกันเพื่อลดก๊าซเรือนกระจก, นฐปัทม์ จิตพิทักษ์ Oct 1998

มาตรการป้องกันเพื่อลดก๊าซเรือนกระจก, นฐปัทม์ จิตพิทักษ์

Thai Environment

No abstract provided.

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แนะนำโครงการของสถาบันวิจัยสภาวะแวดล้อม : โครงการจัดลำดับความสำคัญของปัญหาสิ่งแวดล้อม จากอุตสาหกรรมที่ควรพัฒนางานวิจัยเพื่อการแก้ไข, จันทรา ทองคำเภา Oct 1998

แนะนำโครงการของสถาบันวิจัยสภาวะแวดล้อม : โครงการจัดลำดับความสำคัญของปัญหาสิ่งแวดล้อม จากอุตสาหกรรมที่ควรพัฒนางานวิจัยเพื่อการแก้ไข, จันทรา ทองคำเภา

Thai Environment

No abstract provided.

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อนาคตของป่าไม้ไทยกับการพัฒนาอย่างยั่งยืน, ชัยรัตน์ วงศ์กิจรุ่งเรือง Oct 1998

อนาคตของป่าไม้ไทยกับการพัฒนาอย่างยั่งยืน, ชัยรัตน์ วงศ์กิจรุ่งเรือง

Thai Environment

No abstract provided.

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A Strategic Analysis Of The Rocky Flats Cleanup, Patrick Mccann Oct 1998

A Strategic Analysis Of The Rocky Flats Cleanup, Patrick Mccann

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Rocky Flats Environmental Technology Site is located in Golden, Colorado. It is situated on 384 acres in a 6,550-acre natural preserve. Rocky Flats ended its original mission in 1989, after raids on the site by both the FBI and the EPA for illegal dumping and other environmental violations. Since then the site has been scheduled for cleanup. This thesis will provide background information on the site and on the company hired to perform the cleanup. It also provides an evaluation of some key policies regarding the cleanup procedures. Since the end of the cold war, the production of nuclear …

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Stachybotrys: Is Nevada At Risk?, Terrylynn C. Foley Oct 1998

Stachybotrys: Is Nevada At Risk?, Terrylynn C. Foley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Stachybotrys chartarum (atra) is a toxigenic fungus that is known to adversely impact the health of animals. Until recently, there have only been a few documented clinical reports linking Stachybotrys chartarum to human health effects. Scientists are increasingly convinced that Stachybotrys and its metabolites are responsible for several adverse health effects experienced by people all over the world, although conclusive proof has yet to be established. All the physical requirements needed for indoor Stachybotrys sporulation and growth is provided through water leaks (plumbing, roof or ceiling), flood events, nutrient sources (cellulose and nitrogen), pH, and temperature(23° - 28°C). Stachybotrys has …

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Design And Implementation Of A Maritime Conflict Prediction System, Wee-Keong Ng, Ee Peng Lim, Wen Jing Hsu, Yy Cao Oct 1998

Design And Implementation Of A Maritime Conflict Prediction System, Wee-Keong Ng, Ee Peng Lim, Wen Jing Hsu, Yy Cao

Research Collection School Of Computing and Information Systems

Maritime conflicts have serious impacts on Singapore and the surrounding region both economically and environmentally. This is particularly severe for conflicts such as collisions between large vessels or tankers carrying oil and chemicals. Thus, it is in the interests of the Maritime and Port Authority of Singapore (MPA) to avoid collisions or near-collisions among such vessels navigating through Singapore waters. Existing systems used by MPA predict potential maritime conflicts arising within a short and fixed time horizon. The system produces inconsequential warnings that are often ignored. In this paper, we describe an advanced computerbased system designed to assist in the …

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Isophote-Based Interpolation, Bryan S. Morse, Duane Schwartzwald Oct 1998

Isophote-Based Interpolation, Bryan S. Morse, Duane Schwartzwald

Faculty Publications

Standard methods for image interpolation are based on smoothly fitting the image intensity surface. Recent edge-directed interpolation methods add limited geometric information (edge maps) to build more accurate and visually appealing interpolations at key contours in the image. This paper presents a method for geometry-based interpolation that smoothly fits the isophote (intensity level curve) contours at all points in the image rather than just at selected contours. By using level set methods for curve evolution, no explicit extraction or representation of these contours is required (unlike earlier edge-directed methods). The method uses existing interpolation techniques as an initial approximation and …

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Storm And Base Flow Water Quality For Bear, Calf And Tomahawk Creeks, Kenneth F. Steele, David N. Mott Oct 1998

Storm And Base Flow Water Quality For Bear, Calf And Tomahawk Creeks, Kenneth F. Steele, David N. Mott

Technical Reports

Appendices for MSC 255

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Storm And Base Flow Water Quality For Bear, Calf, And Tomahawk Creeks, Kenneth F. Steele, David N. Mott Oct 1998

Storm And Base Flow Water Quality For Bear, Calf, And Tomahawk Creeks, Kenneth F. Steele, David N. Mott

Technical Reports

Because of the conversion of 92,780 acres of forest to pasture land in the Buffalo River watershed over a 27 year period, there is concern about the affect of agricultural activities on the water quality of the river. Three tributaries (Bear, Calf and Tomahawk creeks) located about mid-length of the Buffalo River were chosen to investigate the affect of agricultural activity on water quality because these streams provide the greatest amounts of fecal bacteria, nitrate+nitrite and phosphorus to the river, despite comprising only 13% of the watershed.

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Wiyn Open Cluster Study. I. Deep Photometry Of Ngc188, Ted Von Hippel, Ata Sarajedini Oct 1998

Wiyn Open Cluster Study. I. Deep Photometry Of Ngc188, Ted Von Hippel, Ata Sarajedini

Publications

We have employed precise and carefully calibrated V - and I - band photometry of NGC 188 at WIYN Observatory to explore the cluster luminosity function (LF) and study the cluster white dwarfs. Our photometry is offset by V = 0.052 (fainter) from that of Sandage and Eggen & Sandage. All published photometry for the past three decades has been based on these two calibrations, which are in error by 0.05 ± 0.01. We employ the Pinsonneault et al. fiducial open cluster main sequence to derive a distance modulus of 11.43 ± 0.08 and E(B - V )=0.09, with …

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Cohomology Of Polynomials Under An Irrational Rotation, Lawrence W. Baggett, Herbert A. Medina, Kathy D. Merrill Oct 1998

Cohomology Of Polynomials Under An Irrational Rotation, Lawrence W. Baggett, Herbert A. Medina, Kathy D. Merrill

Mathematics, Statistics and Data Science Faculty Works

A new description of cohomology of functions under an irrational rotation is given in terms of symmetry properties of the functions on subintervals of [0, 1]. This description yields a method for passing information about the cohomology classes for a given irrational to the cohomology classes for an equivalent irrational.

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Complexity Reduction In State-Based Modeling, Martin Zwick Oct 1998

Complexity Reduction In State-Based Modeling, Martin Zwick

Systems Science Faculty Publications and Presentations

For a system described by a relation among qualitative variables (or quantitative variables "binned" into symbolic states), expressed either set-theoretically or as a multivariate joint probability distribution, complexity reduction (compression of representation) is normally achieved by modeling the system with projections of the overall relation. To illustrate, if ABCD is a four variable relation, then models ABC:BCD or AB:BC:CD:DA, specified by two triadic or four dyadic relations, respectively, represent simplifications of the ABCD relation. Simplifications which are lossless are always preferred over the original full relation, while simplifications which lose constraint are still preferred if the reduction of complexity more …

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Revegetation Strategies For Groundwater Control In The Eastern Wheatbelt, C E. Mcconnell Oct 1998

Revegetation Strategies For Groundwater Control In The Eastern Wheatbelt, C E. Mcconnell

Resource management technical reports

No abstract provided.

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Common Conservation Works Used In Western Australia, M G. Keen Oct 1998

Common Conservation Works Used In Western Australia, M G. Keen

Resource management technical reports

This booklet is presented to assist proponents and planners of conservation works by describing the common types used in Western Australia. For each common type, design criteria are listed along with the variables affecting increased risks associated with degradation or structural failure. This information will be useful in choosing appropriate conservation works to alleviate specific degradation in a safe manner.

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Auger Resonance Decay Process In Ar 2p Shell Excitation And Ionization, Y. Lu, Wayne C. Stolte, J.A. R. Samson Oct 1998

Auger Resonance Decay Process In Ar 2p Shell Excitation And Ionization, Y. Lu, Wayne C. Stolte, J.A. R. Samson

Chemistry and Biochemistry Faculty Research

The production and subsequent autoionization of the Ar+ (1D2)6d1 satellite state that is formed either by shake-up or recapture during the Auger decay of a 2p vacancy in Ar has been studied by photoelectron spectroscopy in the energy region from 243 to 256 eV. The creation of near zero energy electrons below and immediately above the Ar 2p ionization threshold is discussed. Some ambiguous points in previous studies are clarified.

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Validation Of Waimss Incident Duration Estimation Model, Wei Wu, Pushkin Kachroo, Kaan Ozbay Oct 1998

Validation Of Waimss Incident Duration Estimation Model, Wei Wu, Pushkin Kachroo, Kaan Ozbay

Electrical & Computer Engineering Faculty Research

This paper presents an effort to validate the traffic incident duration estimation model of WAIMSS (wide area incident management support system). Duration estimation model of WAIMSS predicts the incident duration based on an estimation tree which was calibrated using incident data collected in Northern Virginia. Due to the limited sample size, a full scale test of the distribution, mean and variance of incident duration was performed only for the root node of the estimation tree, white only mean tests were executed at all other nodes whenever a data subset was available. Further studies were also conducted on the model error …

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Wide-Area Incident Management System On The Internet, Kaan Ozbay, Pushkin Kachroo Oct 1998

Wide-Area Incident Management System On The Internet, Kaan Ozbay, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

The incident management process consists of four sequential steps-incident detection, response, clearance and recovery. Each of these components comprises of a number of operations and coordinated decision-making between the agencies involved. The provision of computer based support tools for the personnel involved will help develop appropriate strategies and increase efficiency and expediency. Existing systems are developed on various traditional computing platforms. However, with the advent of World Wide Web and Internet based programming tools such as Java, it is now possible to develop platform independent decision support tools for the incident management agencies. Any agency will be able to use …

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Vegetation Analysis: A Graphical Analysis Of Plant Succession In Desert Communities Affected By Fire, Jeff Lantow Oct 1998

Vegetation Analysis: A Graphical Analysis Of Plant Succession In Desert Communities Affected By Fire, Jeff Lantow

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mojave Desert is affected by fire every year. With each fire comes the removal of old growth and, in its place, new growth – consisting primarily of those species which thrive in disturbed areas. The focus of my research is to look at plant communities that have been disturbed by fire, and examine the successional pathway of these disturbed environments. The seven environments I analyzed were burned within the last twenty years and are found in the Coleogyne ramosissima ecotone throughout the Spring Mountain range near Las Vegas, Nevada. The data was collected with randomly chosen circle plots in …

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Water Conservation In The Las Vegas Valley, Judith M. Keir Oct 1998

Water Conservation In The Las Vegas Valley, Judith M. Keir

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis deals primarily with residential use of water in the Las Vegas Valley, an arid climate located in the Mojave Desert, and whether the education of people living here has any bearing on whether or not they conserve water. Many of the residents of the Las Vegas Valley have moved from other areas of the country, and perhaps are not aware of the fact that there is a limited supply of water available to the Valley. I believe that people are not necessarily wasteful, and that they would want to conserve water, if they were aware that conservation and …

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