Physical Sciences and Mathematics Commons^™

Groundwater Study Of The Kellerberrin Townsite, T Cattlin

Resource management technical reports

A groundwater study of the townsite of Kellerberrin. It aimed to accelerate the implementation of effective salinity management options. The study consisted of drilling investation and installation of a piezometer network, a pumping test, groundwater flow modelling and a flood risk analysis.

Groundwater Study Of The Moora Townsite, M Deshon

Resource management technical reports

A groundwater study of the townsite of Moora. It aimed to accelerate the implementation of effective salinity management options. The study consisted of drilling investation and installation of a piezometer network, a pumping test, groundwater flow modelling and a flood risk analysis.

Groundwater Study Of The Dowerin Townsite, Louise Hopgood

Resource management technical reports

A groundwater study was carried out for the townsite of Dowerin with the aim of accelerating the implementation of effective salinity management options.

Mode Locking In A Periodically Forced Integrate-And-Fire-Or-Burst Neuron Model, S. Coombes, R. Owen, Gregory D. Smith

Arts & Sciences Articles

The minimal “integrate-and-fire-or-burst” (IFB) neuron model reproduces the salient features of experimentally observed thalamocortical relay neuron response properties, including the temporal tuning of both tonic spiking (i.e., conventional action potentials) and post-inhibitory rebound bursting mediated by the low-threshold Ca2+ current, IT. In previous work focusing on experimental and IFB model responses to sinusoidal current injection, large regions of stimulus parameter space were observed for which the response was entrained to periodic applied current, resulting in repetitive burst, tonic, or mixed (i.e., burst followed by tonic) responses. Here we present an exact analysis of such mode-locking in the integrate-and-fire-or-burst model under …

Mining Multi-Level Rules With Recurrent Items Using Fp'-Tree, Kok-Leong Ong, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Association rule mining has received broad research in the academic and wide application in the real world. As a result, many variations exist and one such variant is the mining of multi-level rules. The mining of multi-level rules has proved to be useful in discovering important knowledge that conventional algorithms such as Apriori, SETM, DIC etc., miss. However, existing techniques for mining multi-level rules have failed to take into account the recurrence relationship that can occur in a transaction during the translation of an atomic item to a higher level representation. As a result, rules containing recurrent items go unnoticed. …

Jointly Coordinating Ecn And Tcp For Rapid Adaptation To Varying Bandwidth, Archan Misra, Teunis Ott

Research Collection School Of Computing and Information Systems

The introduction of service differentiation in the Internet implies that the residual bandwidth available to best-effort traffic becomes highly variable. We explore the design of a rapidly-reactive congestion control framework, where the ECN-aware best-effort flows aggressively go after any unused capacity. By making routers mark packets in a much more aggressive manner, we are able to achieve fast backoff in the network without resorting to the TCP's current drastic step of halving the congestion window. Simulations indicate that our ECN-mod protocol is better than ECN-NewReno in exploiting rapid variations in the available bandwidth. Moreover, the milder backoff policy of ECN-mod …

Hierarchical Mobility Management For Voip Traffic, Archan Misra, Subir Das, Anthony J. Mcauley

Research Collection School Of Computing and Information Systems

A hierarchical IP-based mobility management mechanism is proposed for VoIP applications. The suggested mechanism uses the DMA (dynamic mobility agent) architecture, based on IDMP (intra-domain mobility management protocol), for managing intra-domain mobility and the dynamic binding mechanism of SIP (session initiation protocol) for managing global mobility. This combination of network and application layer mobility management reduces the global signaling load, provides fast handoff for ongoing conversations, enables efficient global transport and supports IP-layer paging.

The Distribution Of Airborne Coal Dust In Soil Profiles Of Norfolk, Va And Its Implication For Arsenic Loading To These Soils, William Joseph Bounds

OES Theses and Dissertations

Norfolk, Virginia is home to the Northern Hemisphere's largest coal terminal the Lamberts Point Docks. The coal loading process of this terminal creates large amounts of coal dust, which subsequently is distributed throughout the local region by atmospheric transport and deposition. While the coal dust itself poses only minor health hazards, certain trace elements within the coal, particularly arsenic, may pose environmental as well as significant health hazards. Within coal, arsenic occurs primarily in the mineral pyrite. As pyrite in the coal dust is subsequently oxidized via exposure to the atmosphere and/or meteoric water, arsenic may be released to the …

Reifying Communication At The Application Level, Andrew P. Black, Jie Huang, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Middleware, from the earliest RPC systems to recent Object-Oriented Remote Message Sending (RMS) systems such as Java RMI and CORBA, claims transparency as one of its main attributes. Coulouris et al. define transparency as “the concealment from the … application programmer of the separation of components in a distributed system.” They go on to identify eight different kinds of transparency.

We considered titling this paper “Transparency Considered Harmful”, but that title is misleading because it implies that all kinds of transparency are bad. This is not our view. Rather, we believe that the choice of which transparencies should be offered …

Modeling And Simulation Of Steady State And Transient Behaviors For Emergent Socs, Joann M. Paul, Arne Suppe, Donald E. Thomas

Research Collection School Of Computing and Information Systems

We introduce a formal basis for viewing computer systems as mixed steady state and non-steady state (transient) behaviors to motivate novel design strategies resulting from simultaneous consideration of function, scheduling and architecture. We relate three design styles: Hierarchical decomposition, static mapping and directed platform that have traditionally been separate. By considering them together, we reason that once a steady state system is mapped to an architecture, the unused processing and communication power may be viewed as a platform for a transient system, ultimately resulting in more effective design approaches that ease the static mapping problem while still allowing for effective …

On Clustering And Retrieval Of Video Shots, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

Clustering of video data is an important issue in video abstraction, browsing and retrieval. In this paper, we propose a two-level hierarchical clustering approach by aggregating shots with similar motion and color features. Motion features are computed directly from 20 tensor histograms, while color features are represented by 30 color histograms. Cluster validity analysis is further applied to automatically determine the number of clusters at each level. Video retrieval can then be done directly based on the result of clustering. The proposed approach is found to be useful particularly for sports games, where motion and color are important visual cues …

Integrating Color And Spatial Features For Content-Based Video Retrieval, Tong Lin, Chong-Wah Ngo, Hong-Jiang Zhang, Qing-Yun Shi

Research Collection School Of Computing and Information Systems

In this paper, we present a novel and efficient scheme for extracting, indexing and retrieving color images. Our motivation was to reduce the space overhead of partition-based approaches taking advantage of the fact that only a relatively low number of distinct values of a particular visual feature is present in most images. To extract color feature and build indices into our image database we take into consideration factors such as human color perception and perceptual range, and the image is partitioned into a set of regions by using a simple classifying scheme. The compact color feature vector and the spatial …

Riparian Restoration, Elizabeth M. Norris, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

Island Arcs, Accretionary Terranes And Midcontinent Structure New Understandings Of The Geologic Architecture Of The U.S. Midcontinent, Marvin P. Carlson

Conservation and Survey Division

A data base collected over the last 100 years, containing both surface and subsurface information, has allowed us to begin to understand the physical framework of Nebraska. We have learned that even in the stable Midcontinent region of North America, there has been an active geologic history. This framework has been deciphered by our programs of surface geologic mapping and by the study of rock samples from both water wells and those deeper test wells for oil and gas. Determining the major structural features across the state (figure 1) has allowed us to better understand both the occurrences of its …

Spectroscopy And Orbital Periods Of Four Cataclysmic Variable Stars, John R. Thorstensen, Cynthia J. Taylor

Dartmouth Scholarship

We present spectroscopy and orbital periods P_orb of four relatively little-studied cataclysmic variable stars. The stars and their periods are: AF Cam, P_orb = 0.324(1) d (the daily cycle count is slightly ambiguous); V2069 Cyg (= RX J2123.7+4217), 0.311683(2) d; PG 0935+075, 0.1868(3) d; and KUV 03580+0614, 0.1495(6) d. V2069 Cyg and KUV 03580+0614 both show He iiλ4686 emission comparable in strength to Hβ. V2069 Cyg appears to be a luminous nova-like variable, and the strong He ii suggests it may be an intermediate polar. The period of KUV 03580+0614 is similar to members …

An Object-Oriented Resource Pool Model In Support Of Discrete Event Simulations, Srinivas Gullapalli

Electrical & Computer Engineering Theses & Dissertations

The proper distribution of resources is a key factor in simulation. Resources provide the supporting facilities, equipment, and personnel for carrying out activities. The number of resources has a direct impact on the overall effectiveness of the simulation as it does in real life. If the number is insufficient, it generally takes more time for the process to complete. On the other hand, if the number is too high, the cost incurred on the resources will be unnecessarily large. Therefore, the count should be a compromise between the two extremes.

In this thesis, an attempt is made to generalize the …

The Crest, Fall 2001, Virginia Institute Of Marine Science

Reports

Table of Contents:

• VIMS Named World Reference Laboratory for Shellfish Diseases
• VIMS Scientists Receive 2001 Best Paper Award
• Domestic Interest Grows in Cobia Culture VIMS Foundation Established
• VIMS Environmental Scientists Spearheading BDE Research in USA
• VIMS Capital Campaign for Kauffman Aquaculture Center Meets its Goal
• Dr. William Reay Named New Manager of Chesapeake Bay National Estuarine Research Reserve
• Summer Course Connects Scientists with Science Teachers
• Beset near 68 degrees south, 69 degrees west
• New researcher studies tiny organisms that play a big role
• VIMS Welcomes New Students
• VIMS to initiate coastal observing program
• VIMS student Receives Dr. Nancy Foster Scholarship …

Weed Plan For Western Australia, State Weed Plan Steering Group, Department Of Agriculture And Food, Western Australia

Bulletins 4000 -

One of the most significant environmental challenges facing Western Australia is the minimisation of the impact of weeds. In the relatively short history of this State since European settlement, some 1155 exotic plant species have established as weeds in our diverse and generally fragile ecosystems. While development for agriculture, mining, transport and housing must by its nature result in some change to the State’s flora, the introduction of weedy plant species has caused serious impacts which cause great concern.

Weeds now pose a serious threat to many of the State’s ecosystems, and impose high annual costs on agricultural industries. Weeds …

Thermodynamic Model For The Prediction Of Ionic Surfactant Influenced Oil Droplet Contact Angles, Samuel Morton, D. Keffer, R. Counce, D. Depaoli, M. Hu

Samuel A Morton

No abstract provided.

Formalization Of Computer Supported Cooperative Work Applications, Carl Chang, Jia Zhang, Tsang Ming Jiang

Jia Zhang

No abstract provided.

Applicability Of General Scenarios To The Architecture Tradeoff Analysis Method, Len Bass, Mark H. Klein, Gabriel A. Moreno

Gabriel A. Moreno

Spectral Energy Distribution Signatures Of Jovian Planets Around White Dwarf Stars., R. Ignace

Richard Ignace

The problem of detecting Jovian-sized planets orbiting white dwarf stars is considered. Significant IR excesses result from warm Jupiters orbiting a white dwarf of T_eff = 10,000 K at a distance of ~10³ white dwarf radii (corresponding to ~10² Jupiter radii or a few tenths of an AU) with an orbital period of ~100 days. Such a planet will have a 10 µm flux density at its Wien peak that is comparable to the emission of the white dwarf at that wavelength. Although the white dwarf is much hotter than the planet, the planet will have peak …

Domain State Susceptibility In Fecl2/Copt-Heterostructures, Christian Binek

Christian Binek Publications

Magnetic heterostructures with perpendicular anisotropy consisting of antiferromagnetic (111)-oriented FeCl2 single crystals and thin ferromagnetic CoPt-multilayers are investigated by ac-susceptometry after cooling in various axial magnetic fields to below the Néel temperature. The freezing process drives the system into a metastable antiferromagnetic domain state which gives rise to a huge excess contribution to the complex parallel susceptibility on heating in zero magnetic field. Its glow curve-like temperature dependence is modeled within the framework of a simple analytical approach. It involves the susceptibility of thermally activated clusters originating from antiferromagnetic stacking faults as well as the contribution of pairs of antiparallel …

Relationships Between Synoptic-Scale Transport And Interannual Variability Of Inorganic Cations In Surface Snow At Summit, Greenland: 1992-1996, J F. Slater, Jack E. Dibb, Barry D. Keim, D W. Kahl

Earth Sciences

To fully utilize the long-term chemical records retrieved from central Greenland ice cores, specific relationships between atmospheric circulation and the variability of chemical species in the records need to be better understood. This research examines associations between the variability of surface snow inorganic cation chemistry at Summit, Greenland (collected during 1992–1996 summer field seasons) and changes in air mass transport pathways and source regions, as well as variations in aerosol source strength. Transport patterns and source regions are determined through 10-day isentropic backward air mass trajectories during a 1 month (late May to late June) common season over the 5 …

Chemical Bonding, Elasticity, And Valence Force Field Models: A Case Study For Α-Pt2si And Ptsi, Gus L. W. Hart, J. E. Klepeis, O. Beckstein, O. Pankratov

Faculty Publications

We have carried out a detailed study of the chemical bonding for two room-temperature stable platinum silicide phases, tetragonal α-Pt2Si. These elements of the bonding are further analyzed by constructing valence force field models using the results from recent first principles calculations of the six (nine) independent, nonzero elastic constants of α-Pt2Si (PtSi). The resulting volume-, radial-, and angular-dependent force constants provide insight into the relative strength of various bonding elements as well as the trends observed in the elastic constants themselves. The valence force field analysis yields quantitative information about the nature of the chemical bonding that is not …

Poynting's Theorem And Luminal Total Energy Transport In Passive Dielectric Media, Scott Glasgow, Michael Ware, Justin Peatross

Faculty Publications

Without approximation the energy density in Poynting's theorem for the generally dispersive and passive dielectric medium is demonstrated to be a system total dynamical energy density. Thus the density in Poynting's theorem is a conserved form that by virtue of its positive definiteness prescribes important qualitative and quantitative features of the medium-field dynamics by rendering the system dynamically closed. This fully three-dimensional result, applicable to anisotropic and inhomogeneous media, is model independent, relying solely on the complex-analytic consequences of causality and passivity. As direct applications of this result, we show 1 that a causal medium responds to a virtual, instantaneous …

The Role Of Predation In Wildlife Population Dynamics, Eric M. Gese, Frederick F. Knowlton

United States Department of Agriculture Wildlife Services: Staff Publications

The role predation plays in the dynamics of prey populations is controversial. Our understandings of predator-prey relationships is complicated by a multitude of factors in the environment and a general lack of knowledge of most ecological systems. Various other factors, besides predation, may regulate or limit prey populations, and various factors influence the degree to which predation affects prey populations. Furthermore, some factors may create time lags, or even cause generational effects, that go unnoticed. Herein, we review the role of predation in wildlife population dynamics, some of the factors influencing predator-prey interactions, and attempt to indicate where the professional …

Measurement Of DΣ/Dm And Forward-Backward Charge Asymmetry For High-Mass Drell-Yan E+E- Pairs From Pp̅ Collisions At √S = 1.8 Tev, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report on a measurement of the mass dependence of the forward-backward charge asymmetry, A_FB, and production cross section dσ /dM for e⁺e^- pairs with mass M_ee> 40 GeV/c². The data sample consists of 108 pb^-1 of pp̅ collisions at √s= 1.8 TeV taken by the Collider Detector at Fermilab during 1992–1995. The measured asymmetry and dσ/dM are compared with the predictions of the standard model and a model with an extra Z′ gauge boson.

Threshold Effects On Angular Distributions For Multiphoton Detachment By Intense Elliptically Polarized Light, Bogdan Borca, M.V. Frolov, N. L. Manakov, Anthony F. Starace

Anthony F. Starace Publications

Unusual threshold effects are found theoretically in the frequency and intensity dependence of angular distributions produced by an elliptically polarized laser as well as in the elliptic dichroism parameter, which measures the asymmetry of the angular distribution.

Fabrication Of Chromium Oxide Nanoparticles By Laser-Induced Deposition From Solution, Z.C. Zhong, R.H. Cheng, Jocelyn Bosley, Peter A. Dowben, David J. Sellmyer

David Sellmyer Publications

We have successfully deposited well-dispersed nanoscale chromium oxide particles by laser-induced solution deposition (LISD) from solution with CrCl₂ and organic solvents. The particles have narrow distributions about three sizes: 230, 350 and 400 nm and are uniform in composition and contain little contamination. We show that LISD is a new technique for producing nanoparticle chromium oxides with uniform composition, controllable size and high yield.