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1998

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Articles 631 - 660 of 2339

Full-Text Articles in Physical Sciences and Mathematics

Field Level Conflict Management In Outdoor Recreation, Arden Anderson Jun 1998

Field Level Conflict Management In Outdoor Recreation, Arden Anderson

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

16 pages.

Contains references.


The User Fee Approach To Hunting And Fishing Finance: The “Teaming With Wildlife” Proposal, R. Max Peterson Jun 1998

The User Fee Approach To Hunting And Fishing Finance: The “Teaming With Wildlife” Proposal, R. Max Peterson

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

18 pages (includes color illustrations).

Contains footnotes.


The Limitations Of A Market-Based Outdoor Recreation Policy: Reasons For Caution, Scott Silver Jun 1998

The Limitations Of A Market-Based Outdoor Recreation Policy: Reasons For Caution, Scott Silver

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

13 pages (includes illustrations).

Contains references.


Precise Measurements Help Gauge Pacific Northwest's Earthquake Potential, M. Meghan Miller, Herb Dragert, Elliot Endo, Jeffrey T. Freymueller, Chris Goldfinger, Harvey M. Kelsey, Eugene D. Humphreys, Daniel J. Johnson, Robert Mccaffrey, John S. Oldow, Anthony Qamar, Charles M. Rubin Jun 1998

Precise Measurements Help Gauge Pacific Northwest's Earthquake Potential, M. Meghan Miller, Herb Dragert, Elliot Endo, Jeffrey T. Freymueller, Chris Goldfinger, Harvey M. Kelsey, Eugene D. Humphreys, Daniel J. Johnson, Robert Mccaffrey, John S. Oldow, Anthony Qamar, Charles M. Rubin

Geological Sciences Faculty Scholarship

Except for the recent rumblings of a few moderate earthquakes and the eruption of Mt. St. Helen's, all has been relatively quiet on the Pacific Northwestern front. The Cascades region in the Pacific Northwest, a sporadically active earthquake and volcanic zone, still has great seismic potential [Atwater, 1987], as comparisons with other subduction zones around the world have shown [Heaton and Kanamori, 1984]. Recent tsunami propagation models [Satake, 1996] and tree ring studies suggest that the last great Cascadia earthquake occurred in the winter of 1700 A.D. and had a magnitude of −8.9. The …


Agenda: Outdoor Recreation: Promise And Peril In The New West, University Of Colorado Boulder. Natural Resources Law Center, Colorado. Bureau Of Land Management Jun 1998

Agenda: Outdoor Recreation: Promise And Peril In The New West, University Of Colorado Boulder. Natural Resources Law Center, Colorado. Bureau Of Land Management

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

Co-sponsored by the Natural Resources Law Center and the Colorado Bureau of Land Management.

The conference will explore several components of the “promise and peril” of the ongoing outdoor recreation explosion. The conference will begin on the morning of June 8 with a series of introductory presentations designed to place the outdoor recreation movement in a useful historical and socioeconomic context. This material will be followed in the afternoon session by a discussion of environmental impacts of outdoor recreation, recognizing that the diversity and magnitude of impacts is as broad as the industry itself. This discussion will be followed on …


Outdoor Recreation And Natural Lands: The Gradual Unfolding Of Policy, Richard L. Knight Jun 1998

Outdoor Recreation And Natural Lands: The Gradual Unfolding Of Policy, Richard L. Knight

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

10 pages.

Contains 2 pages of references.


Environmental Impacts: The Dark Side Of Outdoor Recreation?, Scott G. Miller Jun 1998

Environmental Impacts: The Dark Side Of Outdoor Recreation?, Scott G. Miller

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

14 pages.

Contains 4 pages of references.


Recreation As An Ally For Environmental Protection, Gary Sprung Jun 1998

Recreation As An Ally For Environmental Protection, Gary Sprung

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

10 pages.

Contains references.


The Dilemma Of County And Municipal Open Space Programs: The Case Of Jefferson County, Colorado, Ron Holliday Jun 1998

The Dilemma Of County And Municipal Open Space Programs: The Case Of Jefferson County, Colorado, Ron Holliday

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

7 pages.


Legal Issues In Outdoor Recreation: Trends In Litigation, Ted Zukoski Jun 1998

Legal Issues In Outdoor Recreation: Trends In Litigation, Ted Zukoski

Outdoor Recreation: Promise and Peril in the New West (Summer Conference, June 8-10)

17 pages.


The Synthesis And Characterization Of A Porphyrin Oligomer As A Potential Antenna For Light Harvesting Solar Cells, Tristan Timothy Jenkins Jun 1998

The Synthesis And Characterization Of A Porphyrin Oligomer As A Potential Antenna For Light Harvesting Solar Cells, Tristan Timothy Jenkins

Dissertations and Theses

Mankind's attempts to harvest the sun have resulted in photocells with about 15% overall energy conversion efficiency. The best of these cells consist of a light-sensitive dye attached to a semiconductor. Absorbed light energy is transferred to the semiconductor via the delivery of an excited electron from the dye. Dye electrons are replenished with a redox solution, coupling the dye to the counter electrode.

This research was the beginning of an exploration into some potential improvements in the cell. First of all, the redox solution is a corrosive liquid, and leaks present a problem. A porphyrin oligomer with a TCPP …


Photoadaptation Rate Of Synechococcus Wh7803 Cultures At Two Iron Concentrations, Jon Daniel Moulton Jun 1998

Photoadaptation Rate Of Synechococcus Wh7803 Cultures At Two Iron Concentrations, Jon Daniel Moulton

Dissertations and Theses

The marine cyanobacterium Synechococcus WH7803 adapts to changes in light intensity by changing its photosynthetic physiology. This work is a study o f the rate o f photoadaptation of Synechococcus WH7803 in laboratory cultures. Cultures were shifted from constant 8 µEm-2s-1 light to constant 80 µEm-2s-1 light, from constant 80 µEm-2s-1 light to 8 µEm-2s-1 light and from different light regimes to a single fluctuating light regime. The response of high iron cultures grown in modified aquil culture medium at 5*10-6M Fe was compared with the …


Renormalized Effective Hamiltonian Approach To Qcd, David G. Robertson Jun 1998

Renormalized Effective Hamiltonian Approach To Qcd, David G. Robertson

Physics Faculty Scholarship

Continuing our previous QCD Hamiltonian studies in the gluonic and quark sectors, we describe a new renormalization procedure which generates an effective Hamiltonian. The formulation, which is in the Coulomb gauge, provides an improved framework for investigating hadron structure.


Epidemic Leptospirosis Associated With Pulmonary Hemorrhage—Nicaragua, 1995, Rosalie T. Trevejo, José G. Rigau-Pérez, David A. Ashford, Emily M. Mcclure, Carlos Jarquín-González, Juan J. Amador, José O. De Los Reyes, Alcides Gonzalez, Sherif R. Zaki, Wun-Ju Shieh, Robert G. Mclean, Roger S. Nasci, Robbin S. Weyant, Carole A. Bolin, Sandra L. Bragg, Bradley A. Perkins, Richard A. Spiegel Jun 1998

Epidemic Leptospirosis Associated With Pulmonary Hemorrhage—Nicaragua, 1995, Rosalie T. Trevejo, José G. Rigau-Pérez, David A. Ashford, Emily M. Mcclure, Carlos Jarquín-González, Juan J. Amador, José O. De Los Reyes, Alcides Gonzalez, Sherif R. Zaki, Wun-Ju Shieh, Robert G. Mclean, Roger S. Nasci, Robbin S. Weyant, Carole A. Bolin, Sandra L. Bragg, Bradley A. Perkins, Richard A. Spiegel

United States Department of Agriculture Wildlife Services: Staff Publications

In October 1995, epidemic “hemorrhagic fever,” without jaundice or renal manifestations, was reported in rural Nicaragua following heavy flooding; 2259 residents were evaluated for nonmalarial febrile illnesses (cumulative incidence, 6.1%) and 15 (0.7%) died with pulmonary hemorrhage. A case-control study found that case-patients were more likely than controls to have ever walked in creeks (matched odds ratio [MOR], 15.0; 95% confidence interval [CI], 1.7–132.3), have household rodents (MOR, 10.4; 95% CI, 1.1–97.1), or own dogs with titers ≥ 400 to Leptospira species (MOR, 23.4; 95% CI, 3.6–`). Twenty-six of 51 case-patients had serologic or postmortem evidence of acute leptospirosis. Leptospira …


Boosting A Simple Weak Learner For Classifying Handwritten Digits, Matthew P. Carter Jun 1998

Boosting A Simple Weak Learner For Classifying Handwritten Digits, Matthew P. Carter

Dartmouth College Undergraduate Theses

A weak PAC learner is one which takes labeled training examples and produces a classifier which can label test examples more accurately than random guessing. A strong learner (also known as a PAC learner), on the other hand, is one which takes labeled training examples and produces a classifier which can label test examples arbitrarily accurately. Schapire has constructively proved that a strong PAC learner can be derived from a weak PAC learner. A performance boosting algorithm takes a set of training examples and a weak PAC learning algorithm and generates a strong PAC learner. Our research attempts to solve …


Multiscouting: Guiding Distributed Manipulation With Multiple Mobile Sensors, Michael G. Ross Jun 1998

Multiscouting: Guiding Distributed Manipulation With Multiple Mobile Sensors, Michael G. Ross

Dartmouth College Undergraduate Theses

This thesis investigates the use of multiple mobile sensors to guide the motion of a distributed manipulation system. In our system, multiple robots cooperatively place a large object at a goal in a dynamic, unstructured, unmapped environment. We take the system developed in [Rus, Kabir, Kotay, Soutter 1996], which employs a single mobile sensor for navigational tasks, and extend it to allow the use of multiple mobile sensors. This allows the system to perform successful manipulations in a larger class of spaces than was possible in the single scout model. We focus on the development of a negotiation protocol that …


Distributed Route Planning Using Partial Map Building, Christine J. Alvarado Jun 1998

Distributed Route Planning Using Partial Map Building, Christine J. Alvarado

Dartmouth College Undergraduate Theses

Our goal is to manipulate and guide an object across an unknown environment toward a goal in a known location in space. Our tools include a system of manipulation robots, which are "blind" and one mobile scout robot who relies on a series of sonar sensors for information about the environment. Previous solutions to this problem have taken a simultaneous guiding and manipulating approach, moving the whole system under the scout's guidance. My approach, however, presents a separate scouting algorithm that can return a series of coordinates through which the manipulation system can safely pass to reach the goal in …


B→Sγ Constraints On The Minimal Supergravity Model With Large Tanβ, Howard Baer, Michal Brhlik, Diego Castano, Xerxes Tata Jun 1998

B→Sγ Constraints On The Minimal Supergravity Model With Large Tanβ, Howard Baer, Michal Brhlik, Diego Castano, Xerxes Tata

Chemistry and Physics Faculty Articles

In the minimal supergravity model (MSUGRA), as the parameter tanβ increases, the charged Higgs boson and light bottom squark masses decrease, which can potentially increase contributions from tH±, ̃gbj and Zibj loops in the decay →bsγ. We update a previous QCD improved →bsγ decay calculation to include in addition the effects of gluino and neutralino loops. We find that, in the MSUGRA model, loops involving charginos also increase, and dominate over tW, tH±, ̃g̃q and Zĩq contributions for tanβ≳5−10. We find for large values of tanβ∼35 that most of the parameter space of the MSUGRA model for μ<0 is ruled out due to too large a value of branching ratio B(→bsγ). For μ>0 and …


Abundance And Seasonal Distribution Of The Marbled Murrelet In Puget Sound And Hood Canal In Fall And Winter, Richard Anthony Jensen Merizon Jun 1998

Abundance And Seasonal Distribution Of The Marbled Murrelet In Puget Sound And Hood Canal In Fall And Winter, Richard Anthony Jensen Merizon

Dissertations and Theses

The greater Puget Sound area is home to a diversity of seabirds, however with encroaching human recreational and economic use of these areas these birds are facing unique threats. It is vitally important that we understand where these seabirds occur in order to minimize the risks associated with human influences. Intensive and extensive transects were used to collect data on seasonal distribution and abundance of seabirds, specifically marbled murrelets (Brachyramphus marmoratus), in Puget Sound and Hood Canal. Surveys were conducted from the water during the fall and winter in 1995 and 1996 and summer of 1997. Marbled murrelets were abundant …


High Resolution Seismic Reflection Interpretations Of The Hood Canal-Discovery Bay Fault Zone, Puget Sound, Washington, Brian J. Haug Jun 1998

High Resolution Seismic Reflection Interpretations Of The Hood Canal-Discovery Bay Fault Zone, Puget Sound, Washington, Brian J. Haug

Dissertations and Theses

The north-northeast trending Hood Canal is an elongate 75 km long, 2-5 km wide, maximum 190 m deep glacial trough that represents the western limit of Washington's Puget Sound estuary complex and eastern boundary of the Olympic Peninsula. Airgun seismic reflection data were collected in Hood Canal April 4-5, 1994 onboard the University of Washington's R. V. Thomas G. Thompson for the purpose of defining the enigmatic and relatively unstudied Hood Canal-Discovery Bay fault zone (HDF). This fault zone parallels western Hood Canal, is obscured by marine waters and thick late Quaternary glacio-marine sediments, and is defined locally by gravity …


Physical Properties Of The Binary Star 12 Persei, David J. Barlow, Colin D. Scarfe, Francis C. Fekel Jun 1998

Physical Properties Of The Binary Star 12 Persei, David J. Barlow, Colin D. Scarfe, Francis C. Fekel

Information Systems and Engineering Management Research Publications

We have obtained new radial velocities of the double-lined spectroscopic binary star 12 Persei, whose period is 331 days, and which has been resolved in recent years by speckle interferometry. We derive a solution for the orbital elements from the speckle and radial velocity data simultaneously, and find from that solution masses of 1.306 ± 0.035 and 1.172 ± 0.030 M☉ for the components, and an orbital parallax of 0farcs04224 ± 0farcs00056. We also determine spectroscopically the difference in magnitude between the components and, hence, their absolute magnitudes. We estimate their spectral types and individual colors by fitting standard-star colors …


Table Of Contents Volume Nine, Number Three, Summer 1998, Risk Editorial Board Jun 1998

Table Of Contents Volume Nine, Number Three, Summer 1998, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)


Review Of: Allan Mazur, A Hazardous Inquiry: The Rashomon Effect At Love Canal, Thomas G. Field Jr. Jun 1998

Review Of: Allan Mazur, A Hazardous Inquiry: The Rashomon Effect At Love Canal, Thomas G. Field Jr.

RISK: Health, Safety & Environment (1990-2002)

Review of: Allan Mazur, A Hazardous Inquiry: The Rashomon Effect at Love Canal (Harvard University Press 1998). Abbreviations,, appendices: Chron- ology and The Basics of Toxicology, bibliography, chronology, figures, index, photos, references. LC 97-44639; ISBN 0-674-74833-6 [255+xiv pp. $26.00 Cloth, 79 Garden Street; Cambridge MA 02138.]


Review Of: Charles R. Bennett, Risks In The Environment: How To Assess Them, Penny Dean Jun 1998

Review Of: Charles R. Bennett, Risks In The Environment: How To Assess Them, Penny Dean

RISK: Health, Safety & Environment (1990-2002)

Review of: Charles R. Bennett, Risks in the Environment: How to Assess Them (Burloak Publications 1996). Appendices, references for the appendices, prologue. ISBN 0-9680438-0-1 [305 pp. Paper $23.95. 277 Belvenia Rd., Burlington, Ontario.]


The Discovery Of Trapped Energetic Electrons In The Outer Cusp, R. B. Sheldon, Harlan E. Spence, J. D. Sullivan, T. A, Fritz, Jiasheng Chen Jun 1998

The Discovery Of Trapped Energetic Electrons In The Outer Cusp, R. B. Sheldon, Harlan E. Spence, J. D. Sullivan, T. A, Fritz, Jiasheng Chen

Physics & Astronomy

We report on the POLAR/CEPPAD discovery of a trapped, 60°<θ<120° pitch angle electron population in the outer cusp (7−9+ Re), whose energetic electron component extends from below 30 keV to ∼2 MeV. Because the time variability in the outer cusp precludes mapping with POLAR, we have carried out test particle simulations using the Tsyganenko 1996 model (T96) to demonstrate the trapping of these energy electrons in the outer cusp region and the resonant frequencies of its trapped motion. We discuss the boundaries and regions of the cusp trap and show that it is analogous to the dipole trap. We show that the phase space densities observed there are equal or greater than the phase space densities observed in the radiation belts at constant magnetic moment, thus allowing the possibility of diffusive filling of the radiation belts from the cusp


Long Base-Line Measurements Of Short Period Mesospheric Gravity Waves During The Seek Campaign, Michael J. Taylor, S. H. Seo, T. Nakamura, T. Tsuda, H. Fukunishi, Y. Takahashi Jun 1998

Long Base-Line Measurements Of Short Period Mesospheric Gravity Waves During The Seek Campaign, Michael J. Taylor, S. H. Seo, T. Nakamura, T. Tsuda, H. Fukunishi, Y. Takahashi

All Physics Faculty Publications

Simultaneous observations of short‐period (<1 hour) mesospheric gravity waves were made over an extended base‐line (∼660 km) from two sites in Japan (at Shigaraki and Yamagawa) during the SEEK (Sporadic‐E Experiment over Kyushu) campaign, 9–23 August, 1996. Coincident image data obtained on four nights provided a rare opportunity to investigate the horizontal spatial extent and propagation characteristics of the waves in detail. Surprisingly, out of a total of 12 events observed from Shigaraki and 10 from Yamagawa at most only three exhibited similar propagation characteristics at each site. The majority of the wave displays (∼70–75%) had quite dissimilar characteristics suggesting a preponderance for localized wave motions of limited lifetimes and geographical extent. A marked preference for wave progression towards the N‐NE indicates that the gravity waves imaged in the near infrared OH and OI (557.7 nm) nightglow emissions were probably not directly associated with the observed E‐region irregularities.


The John Muir Newsletter, Summer 1998, The John Muir Center For Regional Studies Jun 1998

The John Muir Newsletter, Summer 1998, The John Muir Center For Regional Studies

Muir Center Newsletters (1981-2015)

John Muir On Mount Ritter: A New Wilderness Aesthetic by Philip G. Terrie (Editor's note: Philip G. Terrie is Professor of English and f American Studies at Bowling Green State University, and author •f Forever Wild: Environmental Aesthetics and the Adirondack wporest Preserve (1985). This article first appeared in The Pacific Historian (1987), and is reproduced here by permission.) hile John Muir has been the subject of considerable scholarly scrutiny in recent years, we have yet to arrive at a complete understanding of his response to nature.1 One on is that we are often too eager to portray him as …


Phase Formation And Magnetic Properties Of Co-Rare Earth Magnetic Films, Yi Liu, Richard A. Thomas, S.S. Malhotra, Z.S. Shan, Sy_Hwang Liou, David J. Sellmyer Jun 1998

Phase Formation And Magnetic Properties Of Co-Rare Earth Magnetic Films, Yi Liu, Richard A. Thomas, S.S. Malhotra, Z.S. Shan, Sy_Hwang Liou, David J. Sellmyer

Sy-Hwang Liou Publications

Co–Sm and Co–Pr films were deposited by dc magnetron sputtering. Transmission electron microscopy and magnetic measurement were used to study the microstructure and magnetic property relationship. The nanostructure of the as-deposited Co 19 at. % Sm films consists of two phases: the amorphous phase and the crystallite phase. Upon annealing at 600 °C, the Co5Sm phase with the Cu5Ca structure, having grain size of about 20 nm, is obtained along with high coercivity (45 kOe). The as-deposited Co 22 at. % Sm films also have nanostructure similar to the Co 19 at. % films except the …


An Implementation Of External-Memory Depth-First Search, Christopher S. Leon Jun 1998

An Implementation Of External-Memory Depth-First Search, Christopher S. Leon

Dartmouth College Undergraduate Theses

In many different areas of computing, problems can arise which are too large to fit in main memory. For these problems, the I/O cost of moving data between main memory and secondary storage (for example, disks) becomes a significant bottleneck affecting the performance of the program. Since most algorithms do not take into account the size of main memory, new algorithms have been developed to optimize the number of I/O's performed. This paper details the implementation of one such algorithm, for external-memory depth-first search. Depth-first search is a basic tool for solving many problems in graph theory, and since graph …


The Effects Of Singular Value Decomposition On Collaborative Filtering, Michael H. Pryor Jun 1998

The Effects Of Singular Value Decomposition On Collaborative Filtering, Michael H. Pryor

Dartmouth College Undergraduate Theses

As the information on the web increases exponentially, so do the efforts to automatically filter out useless content and to search for interesting content. Through both explicit and implicit actions, users define where their interests lie. Recent efforts have tried to group similar users together in order to better use this data to provide the best overall filtering capabilities to everyone. This thesis discusses ways in which linear algebra, specifically the singular value decomposition, can be used to augment these filtering capabilities to provide better user feedback. The goal is to modify the way users are compared with one another, …