Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

1999

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1891 - 1920 of 2348

Full-Text Articles in Physical Sciences and Mathematics

The Nature And Structure Of Impediments To Edi Adoption And Integration: A Survey Of Small- And Medium-Sized Enterprises, Deepak Khazanchi Jan 1999

The Nature And Structure Of Impediments To Edi Adoption And Integration: A Survey Of Small- And Medium-Sized Enterprises, Deepak Khazanchi

Information Systems and Quantitative Analysis Faculty Publications

Electronic data interchange (EDI) is a key enabling component of business-to-business electronic commerce. As firms adopt and integrate advanced information technologies such as EDI, it is important to understand the nature of challenges faced by them. This becomes especially important given the fact that nearly 99.7% of all businesses in the US can be classified as small- to medium-sized enterprises (SMEs). As costs and risks associated with implementing new information technologies decrease, these firms will surely need to focus their attention on managing impediments associated with new technology implementation and learn from the failures or successes of their peer. Consequently, …


Petrology And Geochemistry Of Late-Stage Intrusions Of The A-Type, Mid-Proterozoic Pikes Peak Batholith (Central Colorado, Usa): Implications For Petrogenetic Models, Diane R. Smith, J. Noblett, R. A. Wobus, D. Unruh, J Douglass, R. Beane, C. Davis, S. Goldman, G. Kay, B. Gustavson, B. Saltoun, J. Stewart Jan 1999

Petrology And Geochemistry Of Late-Stage Intrusions Of The A-Type, Mid-Proterozoic Pikes Peak Batholith (Central Colorado, Usa): Implications For Petrogenetic Models, Diane R. Smith, J. Noblett, R. A. Wobus, D. Unruh, J Douglass, R. Beane, C. Davis, S. Goldman, G. Kay, B. Gustavson, B. Saltoun, J. Stewart

Earth and Environmental Geosciences Faculty Research

The ~1.08 Ga anorogenic, A-type Pikes Peak batholith (Front Range, central Colorado) is dominated by coarse-grained, biotite ± amphibole syenogranites and minor monzogranites, collectively referred to as Pikes Peak granite (PPG). The batholith is also host to numerous small, late-stage plutons that have been subdivided into two groups (e.g. Wobus, 1976. Studies in Colorado Field Geology, Colorado School of Mines Professional Contributions, Colorado): (1) a sodic series (SiO2 = ~44–78 wt%; K/Na = 0.32–1.36) composed of gabbro, diabase, syenite/quartz syenite and fayalite and sodic amphibole granite; and (2) a potassic series (SiO2 = ~70–77 wt%; K/Na = 0.95–2.05), …


On The Decomposition Of Order-Separable Posets Of Countable Width Into Chains, Gary Gruenhage, Joe Mashburn Jan 1999

On The Decomposition Of Order-Separable Posets Of Countable Width Into Chains, Gary Gruenhage, Joe Mashburn

Mathematics Faculty Publications

partially ordered set X has countable width if and only if every collection of pairwise incomparable elements of X is countable. It is order-separable if and only if there is a countable subset D of X such that whenever p, q ∈ X and p < q, there is r ∈ D such that p ≤ r ≤ q. Can every order-separable poset of countable width be written as the union of a countable number of chains? We show that the answer to this question is "no" if there is a 2-entangled subset of IR, and "yes" under the Open Coloring Axiom.


Triple Positive Solutions For Multipoint Conjugate Boundary Value Problems, John M. Davis, Paul W. Eloe, Johnny Henderson Jan 1999

Triple Positive Solutions For Multipoint Conjugate Boundary Value Problems, John M. Davis, Paul W. Eloe, Johnny Henderson

Mathematics Faculty Publications

For the nth order nonlinear differential equation y (n)(t)=f(y(t)), t [0,1], satisfying the multipoint conjugate boundary conditions, y (j)(ai) = 0,1 i k, 0 j n i - 1, 0 =a 1 a 2 a k = 1, and i=1 k n i =n, where f: [0, ) is continuous, growth condtions are imposed on f which yield the existence of at least three solutions that belong to a cone.


Vitamin Effect On The Aerobic Biodegradation Of Phenanthrene, Antracene, Fluoranthene, And Pyrene In A Contaminated Soil From An Industrial Site, Ilkay Cam Jan 1999

Vitamin Effect On The Aerobic Biodegradation Of Phenanthrene, Antracene, Fluoranthene, And Pyrene In A Contaminated Soil From An Industrial Site, Ilkay Cam

Theses

Bioremediation of organic wastes is often a cost-effective technology for the in situ treatment of contaminated soils. In this study, the possibility of increasing the rate and extent of biodegradation for phenathrene, anthracene, fluoranthene, and pyrene in an industrial PAH contaminated soil via vitamin mixture supplementation was explored.

Soil contained with PAHs was obtainecl from the Bayway refinery site formerly owned by Exxon (Linden, NJ). Experiments were conducted in which the contaminated soil was amended with a mixtures of four vitamins (niacin, biotin, folic acid, and panthothenic acid). Peat moss, a common soil amendment, was also added in some experiments. …


Brownfield Redevelopment Strategies For Gary, In,, Kirstin Toth, Donald T. Iannone Jan 1999

Brownfield Redevelopment Strategies For Gary, In,, Kirstin Toth, Donald T. Iannone

All Maxine Goodman Levin School of Urban Affairs Publications

The Great Lakes Environmental Finance Center conducted a technical assistance workshop for Gary, Indiana officials on June 29, 1999. This workshop represented an important step in the city’s efforts to address its brownfields cleanup and redevelopment needs. The city has begun its participation in a regionally-awarded brownfields pilot grant from the U.S. Environmental Protection Agency (EPA). The workshop agenda focused discussion on overcoming the barriers to brownfields redevelopment and the financing basics of brownfields redevelopment. These topics were discussed in the context of the redevelopment of the Airport Development Zone and a major area of Gary’s waterfront.


Importance Of Convection And Damping On Rates Of Convergence For The Lax-Wendroff Method, Joseph Kolibal Jan 1999

Importance Of Convection And Damping On Rates Of Convergence For The Lax-Wendroff Method, Joseph Kolibal

Faculty Publications

It is well known that in solving steady state problems using hyperbolic time-stepping methods the intent is to drive the transients to zero as quickly as possible. In this paper the convergence to steady state of the Lax-Wendroff method applied to solving the equations of gas dynamics is analyzed for the Laval nozzle problem by comparing the relative rates of damping and convection using a linearized eigenmode analysis. This analysis is developed for the simpler isenthalpic system and then extended to the full Euler equations. Finally, this allows a comparison between these systems. For both models, useful analytical information can …


On 2-Reptiles In The Plane, Sze-Man Ngai, Víctor F. Sirvent, J. J. P. Veerman, Yang Wang Jan 1999

On 2-Reptiles In The Plane, Sze-Man Ngai, Víctor F. Sirvent, J. J. P. Veerman, Yang Wang

Mathematics and Statistics Faculty Publications and Presentations

We classify all rational 2-reptiles in the plane. We also establish properties concerning rational reptiles in the plane in general.


Geometrical Models For Grain Dynamics, Giovani L. Vasconcelos, J. J. P. Veerman Jan 1999

Geometrical Models For Grain Dynamics, Giovani L. Vasconcelos, J. J. P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

We study models for the gravity-driven, dissipative motion of a single grain on an inclined rough surface. Imposing some conditions on the momentum loss due to the collisions between the particle and the surface, we arrive at a class of models in which the grain dynamics is described by one-dimensional maps. The dynamics of these maps is studied in detail. We prove the existence of various dynamical phases and show that the presence of these phases is independent of the restitution law (within the class considered).


Geometrical Model For A Particle On A Rough Inclined Surface, Giovani L. Vasconcelos, J. J. P. Veerman Jan 1999

Geometrical Model For A Particle On A Rough Inclined Surface, Giovani L. Vasconcelos, J. J. P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

A simple geometrical model is presented for the gravity-driven motion of a single particle on a rough inclined surface. Adopting a simple restitution law for the collisions between the particle and the surface, we arrive at a model in which the dynamics is described by a one-dimensional map. This map is studied in detail and it is shown to exhibit several dynamical regimes (steady state, chaotic behavior, and accelerated motion) as the model parameters vary. A phase diagram showing the corresponding domain of existence for these regimes is presented. The model is also found to be in good qualitative agreement …


Adaptive Resource Management Via Modular Feedback Control, Ashvin Goel, David Steere, Calton Pu, Jonathan Walpole Jan 1999

Adaptive Resource Management Via Modular Feedback Control, Ashvin Goel, David Steere, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

A key feature of tomorrow’s operating systems and runtime environments is their ability to adapt. Current state of the art uses an ad-hoc approach to building adaptive software, resulting in systems that can be complex, unpredictable and brittle. We advocate a modular and methodical approach for building adaptive system software based on feedback control. The use of feedback allows a system to automatically adapt to dynamically varying environments and loads, and allows the system designer to utilize the substantial body of knowledge in other engineering disciplines for building adaptive systems. We have developed a toolkit called SWiFT that embodies this …


Feedback Based Dynamic Proportion Allocation For Disk I/O, Dan Revel, Dylan Mcnamee, Calton Pu, David Steere, Jonathan Walpole Jan 1999

Feedback Based Dynamic Proportion Allocation For Disk I/O, Dan Revel, Dylan Mcnamee, Calton Pu, David Steere, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we propose to use feedback control to automatically allocate disk bandwidth in order to match the rate of disk I/O to the real-rate needs of applications. We describe a model for adaptive resource management based on measuring the relative progress of stages in a producer-consumer pipeline. We show how to use prefetching to transform a passive disk into an active data producer whose progress can be controlled via feedback. Our progress-based framework allows the integrated control of multiple resources. The resulting system automatically adapts to varying application rates as well as to varying device latencies.


Evaluation Of Stream Depletion Considering Finite Stream Width, Shallow Penetration, And Properties Of Streambed Sediments, Vitaly A. Zlotnik, Huihua Huang, James J. Butler Jr. Jan 1999

Evaluation Of Stream Depletion Considering Finite Stream Width, Shallow Penetration, And Properties Of Streambed Sediments, Vitaly A. Zlotnik, Huihua Huang, James J. Butler Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

Commonly used methods for estimation of pumping-induced stream depletion are based on a series of idealistic assumptions about the stream-aquifer interface. In many cases, however, these assumptions are not consistent with field conditions. In order to obtain stream-depletion estimates that are based on assumptions more appropriate for conditions often faced in the field, a new analytical model is proposed. This model, which incorporates the effects of finite stream width, shallow stream penetration, and a low permeability streambed, is based on the Dupuit assumptions and a steady-state representation of flow across the streambed. A general solution for stream depletion is developed …


Lethal Sandslides From Eolian Dunes, David B. Loope, Joseph A. Mason, Lowell Dingus Jan 1999

Lethal Sandslides From Eolian Dunes, David B. Loope, Joseph A. Mason, Lowell Dingus

Department of Earth and Atmospheric Sciences: Faculty Publications

Fossil vertebrates entombed within the Upper Cretaceous Djadokhta Formation of southern Mongolia bear testimony to a heretofore unknown geologic phenomenon: mass wasting of eolian dunes during heavy rainstorms. Evaporation of shallow-penetrating rainwater led to progressive calcite accumulation in a thin layer of sand about 0.5 m below the surface of dune lee slopes. During rare heavy rainstorms, a perched water table developed at the top of calcitic zones. Positive pore water pressure led to translational slides and fast-moving sediment gravity flows that overwhelmed animals on the lee slopes of large dunes and in interdune areas.


Tractor Test 1763: White 6710 Also Agco Allis 8775 (Cummins Engine) Also Agco Rt95, Nebraska Tractor Test Lab Jan 1999

Tractor Test 1763: White 6710 Also Agco Allis 8775 (Cummins Engine) Also Agco Rt95, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


ป่าปะการังโลกกำลังถูกคุกคาม, เพชรมาลัย ธรรมทา Jan 1999

ป่าปะการังโลกกำลังถูกคุกคาม, เพชรมาลัย ธรรมทา

Thai Environment

No abstract provided.


แนะนำโครงการของสถาบันวิจัยสภาวะแวดล้อม : โครงการศึกษาข้อมูลและศักยภาพการพัฒนาแหล่งน้ำ เพื่อการอุตสาหกรรมในเขตกรุงมหานครและปริมณฑล, ธนพรรรณ สุนทระ Jan 1999

แนะนำโครงการของสถาบันวิจัยสภาวะแวดล้อม : โครงการศึกษาข้อมูลและศักยภาพการพัฒนาแหล่งน้ำ เพื่อการอุตสาหกรรมในเขตกรุงมหานครและปริมณฑล, ธนพรรรณ สุนทระ

Thai Environment

No abstract provided.


Redevelopment Strategies For The Usx/Cement Plant Site In Duluth, Minnesota,, Kirstin Toth, Donald T. Iannone Jan 1999

Redevelopment Strategies For The Usx/Cement Plant Site In Duluth, Minnesota,, Kirstin Toth, Donald T. Iannone

All Maxine Goodman Levin School of Urban Affairs Publications

In May 1999, the Great Lakes Environmental Finance Center (GLEFC) conducted a strategy-building workshop in Duluth, Minnesota. The purpose of the workshop was to assist the City of Duluth in its efforts to develop actions leading to the successful redevelopment of the USX/Cement Plant site. Particular emphasis was placed on financing strategies pertinent to properties with a history of environmental contamination, often characterized as brownfields. Due to its long history as an industrial site, the 65-acre Cement Plant had its share of perceived environmental contamination, as well as real contaminants detected during previous site assessments and a current Phase I …


Reviewing Software As A Means Of Enhancing Instruction, Marcus D. Childress, Guang-Lea Lee, Gregory P. Sherman Jan 1999

Reviewing Software As A Means Of Enhancing Instruction, Marcus D. Childress, Guang-Lea Lee, Gregory P. Sherman

Teaching & Learning Faculty Publications

A software review procedure developed by the authors is described. The procedure centers around a form that extends the functionality of traditional software evaluation forms by enhancing the use of the computer software in the early childhood classroom. The form encourages teachers to discover ways a piece of software can be integrated across disciplines and used as an anchor for instruction. Users of the review form are also encouraged to examine ways the software motivates the user to remain engaged in its use. The majority of the review form emphasizes the important role of the teacher in identifying outcomes or …


Algebraic Implementation Of Gauss' Law, Andrzej Herdegen Jan 1999

Algebraic Implementation Of Gauss' Law, Andrzej Herdegen

Turkish Journal of Physics

A C^*-algebraic model may be constructed for the description of asymptotic fields in quantum electrodynamics. In this model charged fields carry the asymptotic Coulomb field of associated charged particles.


Differentiating Type Of Muscle Movement Via Ar Modeling And Neural Network Classification, Beki̇r Karlik Jan 1999

Differentiating Type Of Muscle Movement Via Ar Modeling And Neural Network Classification, Beki̇r Karlik

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this study is to classify electromyogram (EMG) signals for controlling multifunction proshetic devices. An artificial neural network (ANN) implementation was used for this purpose. Autoregressive (AR) parameters of $a_1, a_2, a_3, a_4$ and their signal power obtained from different arm muscle motions were applied to the input of ANN, which is a multilayer perceptron. At the output layer, for 5000 iterations, six movements were distinguished at a high accuracy of 97.6%.


Monitoring The 1996 Drought Using The Standardized Precipitation Index, Michael J. Hayes, Mark D. Svoboda, Donald A. Wilhite, Olga V. Vanyarkho Jan 1999

Monitoring The 1996 Drought Using The Standardized Precipitation Index, Michael J. Hayes, Mark D. Svoboda, Donald A. Wilhite, Olga V. Vanyarkho

National Drought Mitigation Center: Faculty Publications

Droughts are difficult to detect and monitor. Drought indices, most commonly the Palmer Drought Severity Index (PDSI), have been used with limited success as operational drought monitoring tools and triggers for policy responses. Recently, a new index, the Standardized Precipitation Index (SPI), was developed to improve drought detection and monitoring capabilities. The SPI has several characteristics that are an improvement over previous indices, including its simplicity and temporal flexibility, that allow its application for water resources on all timescales. In this article, the 1996 drought in the southern plains and southwestern United States is examined using the SPI. A series …


Design And Optimization Of Chromophores For Liquid Crystal And Photorefractive Applications, Kenneth D. Singer, V. Ostoverkhov, Rolfe G. Petschek Jan 1999

Design And Optimization Of Chromophores For Liquid Crystal And Photorefractive Applications, Kenneth D. Singer, V. Ostoverkhov, Rolfe G. Petschek

Faculty Scholarship

Organic chromophores have been exploited for a wide range of discrete optical and electronic functions as well as a growing number of combined opto-electronic functions. We are pursuing development of organic and polymer materials for a range of applications that require properties including liquid crystallinity, second order optical nonlinearity, photorefractivity and, more recently, special nonlinear optical behavior involving molecular chirality.


An Intelligent Editor For Natural Language Processing Of Unrestricted Text, Demetrios George Glinos Jan 1999

An Intelligent Editor For Natural Language Processing Of Unrestricted Text, Demetrios George Glinos

Retrospective Theses and Dissertations

The understanding of natural language by computational methods has been a continuing and elusive problem in artificial intelligence. In recent years there has been a resurgence in natural language processing research. Much of this work has been on empirical or corpus-based methods which use a data-driven approach to train systems on large amounts of real language data. Using corpus-based methods, the performance of part-of-speech (POS) taggers, which assign to the individual words of a sentence their appropriate part of speech category (e.g., noun, verb, preposition), now rivals human performance levels, achieving accuracies exceeding 95%. Such taggers have proved useful as …


An Iron-Based Ecosystem Model Of The Central Equatorial Pacific, Carrie L. Leonard, Charles R. Mcclain, Ragu Murtugudde, Eileen E. Hofmann, Lawrence W. Harding Jr. Jan 1999

An Iron-Based Ecosystem Model Of The Central Equatorial Pacific, Carrie L. Leonard, Charles R. Mcclain, Ragu Murtugudde, Eileen E. Hofmann, Lawrence W. Harding Jr.

CCPO Publications

The central and eastern equatorial Pacific region is characterized by lower than expected phytoplankton biomass and primary production given the relatively high ambient nitrate concentrations. These unusual conditions have spawned several field programs and laboratory experiments to determine why this high nitrate-low chlorophyll pattern persists in this region. To synthesize the results from these field programs, as well as providing additional evidence in support of the iron hypothesis, we developed a one-dimensional, nine-component ecosystem model of 0 degrees N 140 degrees W. The model components include two phytoplankton size fractions, two zooplankton size fractions, two detrital size fractions, dissolved iron, …


Analyzing Mean Transport Equations Of Turbulence And Linear Disturbances In Decaying Flows, W. D. Thacker, T. B. Gatski, C. E. Grosch Jan 1999

Analyzing Mean Transport Equations Of Turbulence And Linear Disturbances In Decaying Flows, W. D. Thacker, T. B. Gatski, C. E. Grosch

CCPO Publications

The decay of laminar disturbances and turbulence in mean shear-free flows is studied. In laminar flows, such disturbances are linear superpositions of modes governed by the Orr-Sommerfeld equation. In turbulent flows, disturbances are described through transport equations for representative mean quantities. The link between a description based on a deterministic evolution equation and a probability-based mean transport equation is established. Because an uncertainty in initial conditions exists in the laminar as well as the turbulent regime, a probability distribution must be defined even in the laminar case. Using this probability distribution, it is shown that the exponential decay of the …


Modification Of No, Po, And No/Po During Flow Across The Bering And Chukchi Shelves: Implications For Use As Arctic Water Mass Tracers, Lee W. Cooper, Glenn F. Cota, Lawrence R. Pomeroy, Jacqueline M. Grebmeier, Terry E. Whitledge Jan 1999

Modification Of No, Po, And No/Po During Flow Across The Bering And Chukchi Shelves: Implications For Use As Arctic Water Mass Tracers, Lee W. Cooper, Glenn F. Cota, Lawrence R. Pomeroy, Jacqueline M. Grebmeier, Terry E. Whitledge

CCPO Publications

The NO and PO tracers (9[NO3-] + 02 and 135[PO4-] + 02, respectively,) and their derivative NO/PO have found increasing use in Arctic water mass analyses for identifying the specific basin or shelf areas from which surface waters originate, based upon assumed differences in Pacific- and Atlantic-derived content and basin-to-basin differences within the Arctic. Following shipboard sampling in June-September 1993 and May-June 1994, both north and south of Bering Strait, we have found evidence that Pacific-derived waters flowing north to Bering Strait do not necessarily have any unique NO, PO, or NO/PO identity that would permit …


A Two-Dimensional Analytic Tidal Model For A Narrow Estuary Of Arbitrary Lateral Depth Variation: The Intratidal Motion, Chunyan Li, Arnoldo Valle-Levinson Jan 1999

A Two-Dimensional Analytic Tidal Model For A Narrow Estuary Of Arbitrary Lateral Depth Variation: The Intratidal Motion, Chunyan Li, Arnoldo Valle-Levinson

CCPO Publications

An innovative method is introduced to solve a two-dimensional, depth-averaged analytic model for narrow estuaries or tidal channels with arbitrary lateral depth variations. The solution is valid if the lateral variation of the amplitude of tidal elevation (\Delta a\) is small, i.e., \Delta a\ much less than a, where a is the amplitude of the tidal elevation. This assumption is supported by a 60-day observation of elevation in the James River Estuary using pressure sensors at both sides of a cross section of the estuary. The error introduced by the solution is of the order of \Delta a\/a, which has …


Warm Water Formation And Escape In The Upper Tropical Atlantic Ocean - 2. A Numerical Model Study, Sang-Ki Lee, G. T. Csanady Jan 1999

Warm Water Formation And Escape In The Upper Tropical Atlantic Ocean - 2. A Numerical Model Study, Sang-Ki Lee, G. T. Csanady

CCPO Publications

We seek the simplest mass and heat balance scenario within the upper tropical Atlantic Ocean using a 2.5-layer numerical model, with the help of a newly suggested entrainment formula. The model ocean is driven by the seasonal wind and heat flux associated with the movement of the Intertropical Convergence Zone (ITCZ). The entrainment rate is scaled by the product of wind stress and shear at the bottom of the mixed layer. On an annual average, the northward transport of the tropical warm water is about 11 Sv, with roughly 10 Sv associated with entrainment of upper thermocline water. Out of …


Contents Jan 1999

Contents

Journal of Mathematics and Science: Collaborative Explorations

No abstract provided.