Physical Sciences and Mathematics Commons^™

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.

Inequalities For Solutions Of Multipoint Boundary Value Problems, Paul W. Eloe, Johnny Henderson

Mathematics Faculty Publications

The concept of concavity is generalized to functions, y, satisfying nth-order differential inequalities. … An analogous inequality for a related Green’s function is also obtained. These inequalities are useful in applications of certain cone theoretic fixed-point theorems.

Burnett Description For Plane Poiseuille Flow, Alejandro Garcia, F. Uribe

Alejandro Garcia

Two recent works have shown that at small Knudsen number ~K! the pressure and temperature profiles in plane Poiseuille flow exhibit a different qualitative behavior from the profiles obtained by the Navier-Stokes equations. Tij and Santos [J. Stat. Phys. 76, 1399 (1994)] used the Bhatnagar-Gross-Kook model to show that the temperature profile is bimodal and the pressure profile is nonconstant. Malek-Mansour, Baras, and Garcia [Physica A 240, 255 (1997)] qualitatively confirmed these predictions in computer experiments using the direct simulation Monte Carlo method (DSMC). In this paper we compare the DSMC measurements of hydrodynamic variables and non-equilibrium fluxes with numerical …

Constraints On H0 From The Central Velocity Dispersions Of Lens Galaxies, Aaron J. Romanowsky, C. S. Kochanek

Aaron J. Romanowsky

We employ Schwarzschild's method of the orbit modeling to constrain the mass profiles of the central lens galaxies in Q0957+561 and PG 1115+080. We combine the measured, central projected stellar velocity dispersions of these galaxies with the self-similar radial profiles of the rms velocity and of the Gauss-Hermite moment h4 observed in nearby galaxies for 0 lesssim R lesssim 2Reff. For Q0957+561, we find a 16% uncertainty in the galaxy mass and formal 2 σ limits on the Hubble constant of H0=61$\mathstrut{^{+13}_{-15}}$ km s-1 Mpc-1. For PG 1115+080, we find that none of the viable lens models can be ruled …

Exact Neumann Boundary Controllability For Problems Of Transmission Of The Wave Equation, W. Liu, G. H. Williams

Faculty of Informatics - Papers (Archive)

Using the Hilbert Uniqueness Method, we study the problem of exact controllability in Neumann boundary conditions for problems of transmission of the wave equation. We prove that this system is exactly controllable for all initial states in L2(Omega) x (H1(Omaga))'.

Development And Evaluation Of A Standard Weight (WS) Equation For Blue Catfish, Maurice I. Muoneke, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Using a data set composed of 33 populations from six states, we employed the regression-linepercentile technique to develop a standard weight equation for blue catfish Ictalurus furcatus and validated it with an independent data set composed of 43 populations from 10 states. The equation is log₁₀W_s=-6.067+ 3.400 log₁₀TL, where W_s is standard weight in grams and TL is total length in millimeters. The English-unit equivalent (pounds and inches) is log₁₀W_s=-3.950+ 3.400 log₁₀TL. The equation is valid for blue catfish 160 mm (approximately 6 in) TL and longer. …

Body Mass Patterns Predict Invasions And Extinctions In Transforming Landscapes, Craig R. Allen, Elizabeth A. Forys, C. S. Holling

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Scale-specific patterns of resource distribution on landscapes entrain attributes of resident animal communities such that species body-mass distributions are organized into distinct aggregations. Species within each aggregation respond to resources over the same range of scale. This discontinuous pattern has predictive power: invasive species and extinct or declining species in landscapes subject to human transformation tend to be located at the edge of body-mass aggregations (P < 0.01), which may be transition zones between distinct ranges of scale. Location at scale breaks affords species great opportunity, but also potential crisis.

How To Design A Pheasant Management Area, Steven P. Riley

Nebraska Game and Parks Commission: Publications

Content:
Escape, Travel and Displaying Cover
Minimizing Predator Problems with Habitat
General Rules of Thumb
Putting it All Together
Pheasant Habitat Basics
Netting and Roosting Cover
Examples: Based on 40 Acre Blocks

Breeding And Genetics 5: Survival Analysis/Threshold Models, Applications In Survival Analysis, Stephen D. Kachman

Department of Statistics: Faculty Publications

Survival or failure time traits such as herd life and days open are both important economically and pose a number of challenges to an analysis based on linear mixed models. The main features of a survival trait are that it is the time until some event occurs, and some of the observations are censored. Survival models and the associated estimation procedures provide a flexible means of modeling survival traits. In this paper I will discuss the application of survival analysis based on the Weibull distribution. The components that make up a survival model will be presented along with their interpretation. …

Reconstructing Subsets Of Reals, A. J. Radcliffe, A. D. Scott

Department of Mathematics: Faculty Publications

We consider the problem of reconstructing a set of real numbers up to translation from the multiset of its subsets of fixed size, given up to translation. This is impossible in general: for instance almost all subsets of Z contain infinitely many translates of every finite subset of Z. We therefore restrict our attention to subsets of R which are locally finite; those which contain only finitely many translates of any given finite set of size at least 2. We prove that every locally finite subset of R is reconstructible from the multiset of its 3-subsets, given up to …

Salinity Action Plan : Wetland Vegetation Monitoring, 1998/1999, R. Gurner, G. Ogden, R. H. Froend

Research outputs pre 2011

This report represents the vegetation component of a project designed to provide on-going monitoring of wetland salinity and biological resources in wetlands of the agricultural zone of south-west Western Australia. Maintenance of wetland biological diversity in the agricultural zone is one of the major objectives of the Salinity Action Plan. Due to their low position in the landscape, wetlands are the habitat most affected by salinisation...

Locating Napls In Ground Water Using Partitioning Fluorescent Dyes, A. Ghanem, J. Smith, M. Elzey, T. S. Soerens, M. A. Miah, G. Thoma

Journal of the Arkansas Academy of Science

A major challenge in ground water remediation is locating nonaqueous phase liquids (NAPLs). Partitioning tracers can be used to identify NAPL sources between injection and extraction wells. NAPLs are only slightly soluble in water, pose a long-term source of groundwater contamination, and can be difficult to remove. The complexity of recovery processes requires the development of new technologies that guarantee cost effective methods for locating and quantifying NAPLs. Traditional methods like soil coring have been inefficient since they underestimate the quantity of NAPLs and are expensive. Partitioning tracer tests are some of the most recent methods developed for locating these …

The Association Of Fluid Intake With Total Natural-Cause Mortality, Coronary Heart Disease And Fatal Stroke, Jacqueline Chung Lun Chan

Loma Linda University Electronic Theses, Dissertations & Projects

Hypohydration may be more widespread than realized since it does not always arouse a sense of thirst. When thirst is felt, it is often ignored, or satisfied before euhydration is achieved. There is growing evidence indicating that hypohydration contributes to acute and chronic illnesses, and to rheological factors associated with coronary heart disease (CHD) and stroke. Therefore the relationship of fluid intake with risk of total natural-cause mortality, CHD and stroke death was examined using data on 34,192 white, non-Hispanic participants in the Adventist Health Study.

Among the 27,342 reporting no CHD, stroke or diabetes at baseline, during six years …

Managing Mountain Bike Impacts In The South West Of Western Australia : Combining Biophysical Impact Studies With Rider Preferences For Better Trail Design, Ute Goeft

Theses : Honours

This thesis examines the environmental impacts of mountain bikes on trails in the southwest of Western Australia and the preferences, perceptions, trail use and demographics of mountain bike riders in that region. This information is important for resource managers and trail developers to ensure that the trails that are provided and planned for mountain bike use in the region are environmentally appropriate and acceptable to users. The environmental impacts were examined through biophysical studies, which investigated soil loss, soil compaction and vegetation damage on and adjacent to mountain bike trails over a period of six months. A mountain bike racing …

An Algorithm For Optimal Winner Determination In Combinatorial Auctions, Tuomas Sandholm

All Computer Science and Engineering Research

Combinatorial auctions, i.e. auctions where bidders can bid on combinations of items, tend to lead to more efficient allocations than traditional auctions in multi-item auctions where the agents' valuations of the items are not additive. However, determining the winners so as to maximize revenue is NP-complete. First, existing approaches for tackling this problem are reviewed: exhaustive enumeration, dynamic programming, approximation algorithms, and restricting the alloable combinations. Then we present our search algorithm for optimal winner determination. Experiments are shown on several bid distributions. The algorithm allows combinatorial auctions to scale up to significantly larger numbers of items and bids than …

Revenue Equivalence Of Leveled Commitment Contracts, Tuomas Sandholm, Yunhong Zhou

All Computer Science and Engineering Research

In automated negotiation systems consisting of self-interested agents, contracts have traditionally been binding. Leveled commitment contracts - i.e. contracts where each party can decommit by paying a predetermined penalty - were recently shown to improve expected social welfare even if agents decommit insincerely in Nash equilibrium. Such contracts differ based on whether agents have to declare their decommitting decisions sequentially or simultaneously, and whether or not agents have to pay the penalties if both decommit. For a given contract, these protocols lead to different decommitting thresholds and probabilities. However, this paper shows that, surprisingly, each protocol leads to the same …

A Proposal For A High-Performance Active Hardware Architecture, Tilman Wolf

All Computer Science and Engineering Research

Current research in Active Networking is focused on developing software architectures and defining funtionality of Execution Environments. While active network systems show superior functionality compared to traditional networks, they only operate at substantially lower link speeds. To increase the acceptance of Active Network in environments where link speeds of several Gb/s are common, we propose a hardware architecture that performs high-speed packet handling while providing the same flexibility as a common software system. The design exploits the independence between data streams for parallel processing. To measure the impact of different design decisions on the performance of the system, we also …

The Design And Performance Of A Pluggable Protocols Framework For Object Request Broker Middleware, Fred Kuhns, Carlos O'Ryan, Douglas C. Schmidt, Jeff Parsons

All Computer Science and Engineering Research

To be an effective platform for performance-sensitive real-time and embedded applications, off-the-shelf OO middleware like CORBA, DCOM, and Java RMI must preserve communication-layer quality of service (QoS) properties to applications end-to-end. However, conventional OO middleware interoperability protocols, such as CORBA's GIOP/IIOP or DCOM's MS-RPC, are not well suited for applications that cannot tolerate the message footprint size, latency, and jitter associated with general-purpose messaging and transport protocols. It is essential, therefore, to develop standard plugable protocols frameworks that allow custom messaging and transport protocols to be configured flexibly and used transparently by applications. This paper provides three contributions to research …

Anmac: A Novel Architectural Framework For Network Management And Control Using Active Networks, Samphel Norden

All Computer Science and Engineering Research

In this paper, we propose a new framework called Active Network Management and Control (ANMAC) for the management and control of high speed networks. The software architecture in ANMAC allows routers to execute dynamically loadable kernel plug-in modules which perform diagnostic functions for network management. ANMAC uses mobile probe packets to perform efficient resource reservation (using our novel reservation scheme), facilitate feedback-based congestion control, and to provide "distributed debugging" of complex anomalous network behavior. ANMAC also provides security measures against IP spoofing, and other security attacks. The network manager has the flexibility to install custom scripts in routers for tracking …

Emediator: A Next Generation Electronic Commerce Server, Tuomas Sandholm

All Computer Science and Engineering Research

This paper presents eMediator, a next generation electronic commerce server that demonstrates some ways in which AI, algorithmic support, and game theoretic incentive engineering can jointly improve the efficiency of ecommerce. First, its configurable auction house includes a variety of generalized combinatorial auctions, price setting mechanism, novel bid types, mobile agents, and user support for choosing an auction type. Second, its leveled commitment contract optimizer determines the optimal contract price and decommitting penalties for a variety of leveled commitment contracting protocols, taking into account that rational agents will decommit insincerely in taking into account that rational agents will decommit insincerely …

Algorithms For Optimizing Leveled Commitment Contracts, Thomas Sandholm, Sandeep Sikka, Samphel Norden

All Computer Science and Engineering Research

In automated negotiation systems consisting of self-interested agents, contracts have traditionally been binding. Leveled commitment contracts - i.e. contracts where each party can decommit by paying a predetermined penalty - were recently shown to improve Pareto efficiency even if agents rationally decommit in Nash equilibrium using inflated thresholds on how good their outside offers must be before they decommit. This paper operationalizes the four leveled commitment contracting protocols by presenting algorithms for using them. Algorithms are presented for computing the Nash equilibrium decomitting thresholds and decommitting probabilities given the contract price and the penalties. Existence and uniqueness of the equilibrium …

Optimal Flow Aggregation, Subhash Suri, Tuomas Sandholm, Priyank Warkhede

All Computer Science and Engineering Research

Current IP routers are stateless: they forward individual packets based on the destination address contained in the packet header, but maintain no information about the application or flow to which a packet belongs. This stateless service model works well for best effort datagram delivery, but is grossly inadequate for applications that require quality of service guarantees, such as audio, video, or IP telephony. Maintaining state for each flow is expensive because the number of concurrent flows at a router can be in the hundreds of thousands. Thus, stateful solutions such as Intserv (integrated services) have not been adopted for their …

Multiway Range Trees: Scalable Ip Lookup With Fast Updates, Subhash Suri, George Varghese, Piryank Ramesh Warkhede

All Computer Science and Engineering Research

Internet routers forward packets based on the destination address of a packet. A packet's address is matched against the destination prefixes stored in the router's forwarding table, and the packet is sent to the output interface determined by the longest matching prefix. While some existing schemes work well for IPv4 addresses, we believe that none of the current schemes scales well to IPv6, especially when fast updates are required. As the Internet evolves into a global communication medium, requiring multiple addresses per user, the switch to longer addresses (e.g. IPv6) seems inevitable despite temporary measures such as network addres translation …

Pattern Matching Techniques And Their Applications To Computational Molecular Biology - A Review, Eric C. Rouchka

All Computer Science and Engineering Research

Pattern matching techniques have been useful in solving many problems associated with computer science, including data compression (Chrochemore and Lecroq, 1996), data encryption (RSA Laboratories, 1993), and computer vision (Grimson and Huttenlocher, 1990). In recent years, developments in molecular biology have led to large scale sequencing of genomic DNA. Since this data is being produced in such rapid fasion, tools to analyze DNA segments are desired. The goal here is to discuss various techniques and tools for solving various pattern matching questions in computational biology, including optimal sequence alignment, multiple sequence alignment, and buidling models to describe sequence families using …

Design Issues For High Performance Active Routers, Tilman Wolf, Jonathan Turner

All Computer Science and Engineering Research

Active networking is a general approach to incorporating general-purpose computational capabilities within the communications infrastructure of data networks. This paper proposes a design of a scalable, high performance active router. This is used as a vehicle for studying the key design issues that must be resolved to allow active networking to become a mainstream technology.

Commbench - A Telecommunications Benchmark For Network Processors, Tilman Wolf, Mark Franklin

All Computer Science and Engineering Research

This paper presents a benchmark, CommBench, for use in evaluating and designing telecommunications network processors. The benchmark applications focus on small, computationally intense program kernels typical of the network processor environment. The benchmark is composed of eight programs, four of them oriented towards packet header processing and four oriented towards data stream procesing. The benchmark is defined and various characteristics of the benchmark are presented. These include instruction frequencies, computational complexity, and cache performance. These measured characteristics are compared to the SPEC benchmark which has traditionally been used in evaluating workstation processors. Three examples are presented indicating how CommBench can …

Tracking Mobile Units For Dependable Message Delivery, Amy L. Murphy, Gruia-Catalin Roman, George Varghese

All Computer Science and Engineering Research

As computing components get smaller and people become accustomed to having computational power at their disposal at any time, mobile computing is developing as an important research area. One of the fundamental problems in mobility is maintaining connectivity through message passing as the user moves through the network. An approach to this is to have a single home node constantly track the current location of the mobile unit and forward messages to this location. One problem with this approach is that during the update to the home agent after movement, messages are often dropped, especially in the case of frequent …

Transition From Research To Operations: Arktos - A Knowledge-Based Sea Ice Classification System, Cheryl Bertoia, Denise Gineris, Kim Partington, Leen-Kiat Soh, Costas Tsatsoulis

CSE Conference and Workshop Papers

ARKTOS is a fully automated intelligent system that classifies sea ice and that is now being used by the U.S. National Ice Center (NIC) for daily operations related to the NIC’s task of mapping the ice covered oceans. In this paper we describe the process of taking a research project and transitioning it to an operational environment. We discuss the theoretical methodologies implemented in ARKTOS, and how ARKTOS was developed, tested, and finally moved to operations.

A Dual Encryption Protocol For Scalable Secure Multicasting, Lakshminath R. Dondeti, Sarit Mukherjee, Ashok K. Samal

CSE Conference and Workshop Papers

In this paper we propose a dual encryption protocol for scalable secure multicasting. Multicasting is a scalable solution for group communication. It howevel; poses several unique security problems. We use hierarchical subgrouping to achieve scalability. Third party hosts or members of the multicast group are designated as subgroup managers. They are responsible for secret key distribution and group membership management at the subgroup level. Unlike existing secure multicast protocols, our protocol need not trust the subgroup managers with the distribution of data encryption keys. The dual encryption protocol proposed in this paper distributes encrypted data encryption keys via subgroup managers. …

Routing Algorithms For All-Optical Networks With Power Considerations: The Unicast Case, Maher Ali, Byrav Ramamurthy, Jitender S. Deogun

CSE Conference and Workshop Papers

In this paper, we investigate the problem of routing connections in all-optical networks while allowing for degradation of routed signals by different optical components. To overcome the complexity of the problem, we divide it into two parts. First, we solve the pure RWA problem using fixed routes for every connection. Second, power assignment is accomplished by either using the smallest-gain first (SGF) heuristic or using a genetic algorithm. Numerical examples on a wide variety of networks show that (a) the number of connections established without considering the signal attenuation was most of the time greater than that achievable considering attenuation …