Physical Sciences and Mathematics Commons^™

Integrated Coverage And Connectivity Configuration For Energy Conservation In Sensor Networks, Guoliang Xing, Xiaorui Wang, Yuanfang Zhang, Chenyang Lu, Robert Pless, Christopher Gill

All Computer Science and Engineering Research

An effective approach for energy conservation in wireless sensor networks is scheduling sleep intervals for extraneous nodes, while the remaining nodes stay active to provide continuous service. For the sensor network to operate successfully, the active nodes must maintain both sensing coverage and network connectivity. Fur-thermore, the network must be able to configure itself to any feasible degrees of coverage and connectivity in order to support different applications and environments with diverse requirements. This paper presents the design and analysis of novel protocols that can dynamically configure a network to achieve guaranteed degrees of coverage and connectivity. This work differs …

Query Processing Using Negative Tuples In Stream Query Engines, T. Ghanem, M. Hammad, M. Mokbel, Walid G. Aref, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.

Energy-Efficient Routing And Data Aggregation In Sensor Networks: An Experimental Study, Ossama Younis, Sonia Fahmy

Department of Computer Science Technical Reports

No abstract provided.

Fisheries Research Contract Report No. 10 - Mother-Of-Pearl Shell (Pinctada Maxima): Stock Evaluation For Management And Future Harvesting In Western Australia, Anthony M. Hart, Kim J. Friedman

Fisheries Research Contract Reports

The West Australian Pearling industry is one of Australia's most valuable aquaculture industries, currently generating around $120 - $160 million annually. The majority of pearl shell used to culture pearls come from the pearling beds in the inshore waters near Broome. The fishery for pearl oysters preferentially targets smaller (120mm - 165mm DVM) shell (hereafter defined as 'culture' shell), that are more suitable for culturing of pearls, leaving larger MOP oysters (175mm+) on the pearling grounds. These larger pearl oysters, the majority of which are female (protandric hermaphrodites), form a major component of the broodstock for the

fishery. Although MOP …

Evaluating The Use Of In Vitro Bioassays For The Ecotoxicological Assessment Of Irish Estuarine Sediments, Sharon Ni Shuilleabhain

Doctoral

Sediments, as a repository for persistent anthropogenic contaminants, have the potential to cause deleterious effects in the aquatic environment. Particular attention to the quality of sediment is, therefore, warranted in the ecotoxicological risk assessment of aquatic systems. An assessment methodology combining chemical, ecotoxicological and ecological evaluations in a hierarchial test strategy, where toxicological significant and complexity increases with the tiers, is recommended for a thorough appraisal of sediment toxicity. The aim of the present study was to assess the potential of in vitro bioassays to be employed as screening tools got Tier 1 ecotoxicity evaluation of Irish estuarine sediments. Chemical …

Comparison Of Auto-Adjusting And Fixed Level Continuous Positive Airway Pressure Therapy In Patients With Mild To Moderate Obstructive Sleep Apnoea Hypopnoea Syndrome, Geraldine Nolan

Masters

Obstructive Sleep Apnoea Hypopnoea syndrome (OSAHS) is a potentially serious medical disorder associated with increased morbidity and mortality. It is estimated to affect 4% of males and 2% of females between the ages of forty and sixty. Nasal continuous positive airway pressure (CPAP) is the first choice treatment for this condition and it is extremely effective at controlling OSAHS. However, not all patients can tolerate this therapy, in particular those within the mild to moderate category, and there are also many others who are unable to comply with the minimum usage requirements of at least four hours every night. A …

Two-Loop Bethe Logarithms For Higher Excited S Levels, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

Processes mediated by two virtual low-energy photons contribute quite significantly to the energy of hydrogenic S states. The corresponding level shift is of the order of ( α / π )² ( Z α )⁶ m_ec² and may be ascribed to a two-loop generalization of the Bethe logarithm. For 1 S and 2 S states, the correction has recently been evaluated by Pachucki and Jentschura [Phys. Rev. Lett. 91, 113005 (2003)]. Here, we generalize the approach to higher excited S states, which in contrast to the 1 S and 2 S states can decay to …

Nucleation Rates Of Water And Heavy Water Using Equations Of State, Abdalla Obeidat, Jin-Song Li, Gerald Wilemski

Physics Faculty Research & Creative Works

The original formula of Gibbs for the reversible work of critical nucleus formation is evaluated in three approximate ways for ordinary and heavy water. The least approximate way employs an equation of state to evaluate the pressure difference between the new and old phases. This form of the theory yields a temperature dependence for the nucleation rate close to that observed experimentally. This is a substantial improvement over the most commonly used (and most approximate) form of classical theory.©2004 American Institute of Physics.

Multivariate Stochastic Volatility Models: Bayesian Estimation And Model Comparison, Jun Yu, Renate Meyer

Research Collection School Of Economics

In this paper we show that fully likelihood-based estimation and comparison of multivariate stochastic volatility (SV) models can be easily performed via a freely available Bayesian software called WinBUGS. Moreover, we introduce to the literature several new specifications which are natural extensions to certain existing models, one of which allows for time varying correlation coefficients. Ideas are illustrated by fitting, to a bivariate time series data of weekly exchange rates, nine multivariate SV models, including the specifications with Granger causality in volatility, time varying correlations, heavy-tailed error distributions, additive factor structure, and multiplicative factor structure. Empirical results suggest that the …

On Semantic Caching And Query Scheduling For Mobile Nearest-Neighbor Search, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Location-based services have received increasing attention in recent years. In this paper, we address the performance issues of mobile nearest-neighbor search, in which the mobile user issues a query to retrieve stationary service objects nearest to him/her. An index based on Voronoi Diagram is used in the server to support such a search, while a semantic cache is proposed to enhance the access efficiency of the service. Cache replacement policies tailored for the proposed semantic cache are examined. Moreover, several query scheduling policies are proposed to address the inter-cell roaming issues in multi-cell environments. Simulations are conducted to evaluate the …

Complex Multiplication Of Exactly Solvable Calabi-Yau Varieties, Monika Lynker, Rolf Schimmrigk, Steven Stewart

Faculty Articles

We propose a conceptual framework that leads to an abstract characterization for the exact solvability of Calabi–Yau varieties in terms of abelian varieties with complex multiplication. The abelian manifolds are derived from the cohomology of the Calabi–Yau manifold, and the conformal field theoretic quantities of the underlying string emerge from the number theoretic structure induced on the varieties by the complex multiplication symmetry. The geometric structure that provides a conceptual interpretation of the relation between geometry and conformal field theory is discrete, and turns out to be given by the torsion points on the abelian varieties.

A Survey Of Wpa And 802.11i Rsn Authentication Protocols, Kwang-Hyun Baek, Sean W. Smith, David Kotz

Computer Science Technical Reports

In the new standards for WLAN security, many choices exist for the authentication process. In this paper, we list eight desired properties of WLAN authentication protocols, survey eight recent authentication protocols, and analyze the protocols according to the desired properties.

Accommodating Instance Heterogeneities In Database Integration, Ee Peng Lim, Roger Hsiang-Li Chiang

Research Collection School Of Computing and Information Systems

A complete data integration solution can be viewed as an iterative process that consists of three phases, namely analysis, derivation and evolution. The entire process is similar to a software development process with the target application being the derivation rules for the integrated databases. In many cases, data integration requires several iterations of refining the local-to-global database mapping rules before a stable set of rules can be obtained. In particular, the mapping rules, as well as the data model and query model for the integrated databases have to cope with poor data quality in local databases, ongoing local database updates …

Spatial Queries In Wireless Broadcast Systems, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Owing to the advent of wireless networking and personal digital devices, information systems in the era of mobile computing are expected to be able to handle a tremendous amount of traffic and service requests from the users. Wireless data broadcast, thanks to its high scalability, is particularly suitable for meeting such a challenge. Indexing techniques have been developed for wireless data broadcast systems in order to conserve the scarce power resources in mobile clients. However, most of the previous studies do not take into account the impact of location information of users. In this paper, we address the issues of …

The D-Tree: An Index Structure For Planar Point Queries Location-Based Wireless Services, Jianliang Xu, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Location-based services (LBSs), considered as a killer application in the wireless data market, provide information based on locations specified in the queries. In this paper, we examine the indexing issue for querying location-dependent data in wireless LBSs; in particular, we focus on an important class of queries, planar point queries. To address the issues of responsiveness, energy consumption, and bandwidth contention in wireless communications, an index has to minimize the search time and maintain a small storage overhead. It is shown that the traditional point-location algorithms and spatial index structures fail to achieve either objective or both. This paper proposes …

Corrective Maintenance Optimization In An Air Force, Hoong Chuin Lau, K. Y. Neo, W. C. Wan

Research Collection School Of Computing and Information Systems

Successful military mission planning and execution depend critically on equipment serviceability and resupply. Due to the stochastic nature of demands, the forecast of optimal spares and resources needed to guarantee the level of serviceability is a complex problem, especially in a multi-echelon setting. In this paper, we propose a decision-support concept and software tool known as Corrective Maintenance Optimizer (CMO) that helps to optimize system availability, through proper allocation of spare parts, both strategically and operationally.

Job Scheduling With Unfixed Availability Constraints, Hoong Chuin Lau, C. Zhang

Research Collection School Of Computing and Information Systems

Standard scheduling theory assumes that all machines are continuously available throughout the planning horizon. In many manufacturing and service management situations however, machines need to be maintained periodically to prevent malfunctions. During the maintenance period, a machine is not available for processing jobs. Hence, a more realistic scheduling model should take into account machine maintenance activities. In this paper, we study the problem of job scheduling with unfixed availability constraints on a single machine. We first propose a preliminary classification for the scheduling problem with unfixed availability constraints based on maintenance constraints, job characteristics and objective function. We divide our …

Logistics Network Design With Differentiated Delivery Lead Time: A Chemical Industry Case Study, Michelle Lee Fong Cheong, Rohit Bhatnagar, Stephen C. Graves

Research Collection School Of Computing and Information Systems

Most logistics network design models assume exogenous customer demand that is independent of the service time or level. This paper examines the benefits of segmenting demand according to lead-time sensitivity of customers. To capture lead-time sensitivity in the network design model, we use a facility grouping method to ensure that the different demand classes are satisfied on time. In addition, we perform a series of computational experiments to develop a set of managerial insights for the network design decision making process.

Two-Echelon Repairable Item Inventory System With Limited Repair Capacity Under Nonstationary Demands, Hoong Chuin Lau, Huawei Song

Research Collection School Of Computing and Information Systems

We study a repairable item inventory system under limited repair capacity and nonstationary Poisson demands, motivated by corrective maintenance of military equipment. Our goal is to minimize the cost of both spare and repair resource allocation. We propose an efficient analytical model that combines optimization modeling and queuing theory.

Finding Constrained Frequent Episodes Using Minimal Occurrences, Xi Ma, Hwee Hwa Pang, Kian-Lee Tan

Research Collection School Of Computing and Information Systems

Recurrent combinations of events within an event sequence, known as episodes, often reveal useful information. Most of the proposed episode mining algorithms adopt an apriori-like approach that generates candidates and then calculates their support levels. Obviously, such an approach is computationally expensive. Moreover, those algorithms are capable of handling only a limited range of constraints. In this paper, we introduce two mining algorithms - episode prefix tree (EPT) and position pairs set (PPS) - based on a prefix-growth approach to overcome the above limitations. Both algorithms push constraints systematically into the mining process. Performance study shows that the proposed algorithms …

A Periodic-Review Inventory Model With Application To The Continuous-Review Obsolescence Problem, Yuyue Song, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In this paper we consider a stochastic-demand periodic-review inventory model with sudden obsolescence. We characterize the structure of the optimal policy and propose a dynamic programming algorithm for computing its parameters. We then utilize this algorithm to approximate the solution to the continuous-review sudden obsolescence problem with general obsolescence distribution. We prove convergence of our approximation scheme, and demonstrate it numerically against known closed-form solutions of special cases.

Anonymous Secure Routing In Mobile Ad-Hoc Networks, Bo Zhu, Zhiguo Wan, Mohan S. Kankanhalli, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

Although there are a large number of papers on secure routing in mobile ad-hoc networks, only a few consider the anonymity issue. In this paper, we define more strict requirements on the anonymity and security properties of the routing protocol, and notice that previous research works only provide Weak Location Privacy and Route Anonymity, and are vulnerable to specific attacks. Therefore, we propose the Anonymous Secure Routing (ASR) protocol that can provide additional properties on anonymity, i.e. Identity Anonymity and Strong Location Privacy, and at the same time ensure the security of discovered routes against various passive and active attacks. …

How Cellular Movement Determines The Collective Force Generated By The Dictyostelium Discoideum Slug, J. C. Dallon, H. G. Othmer

Faculty Publications

How the collective motion of cells in a biological tissue originates in the behavior of a collection of individuals, each of which responds to the chemical and mechanical signals it receives from neighbors, is still poorly understood. Here we study this question for a particular system, the slug stage of the cellular slime mold Dictyostelium discoideum. We investigate how cells in the interior of a migrating slug can effectively transmit stress to the substrate and thereby contribute to the overall motive force. Theoretical analysis suggests necessary conditions on the behavior of individual cells, and computational results shed light on experimental …

Bayesian Hierarchical Distributed Lag Models For Summer Ozone Exposure And Cardio-Respiratory Mortality, Yi Huang, Francesca Dominici, Michelle L. Bell

Johns Hopkins University, Dept. of Biostatistics Working Papers

In this paper, we develop Bayesian hierarchical distributed lag models for estimating associations between daily variations in summer ozone levels and daily variations in cardiovascular and respiratory (CVDRESP) mortality counts for 19 U.S. large cities included in the National Morbidity Mortality Air Pollution Study (NMMAPS) for the period 1987 - 1994.

At the first stage, we define a semi-parametric distributed lag Poisson regression model to estimate city-specific relative rates of CVDRESP associated with short-term exposure to summer ozone. At the second stage, we specify a class of distributions for the true city-specific relative rates to estimate an overall effect by …

Evaluation Of Extent And Bioavailability Of Chromium Contamination Near An Abandoned Strip Mine, C. Appel, J. Stuckey, A. Cosley, R. Donald, C. Griffith, S. Lager, M. Perry, T. Ray, P. Smith

Earth and Soil Sciences

Chromium is a potentially toxic element to plants and animals commonly associated with serpentine and anthropogenic sources. An abandoned Cr strip-mine at US National Guard Camp SLO, CA containing serpentinitic parent material was tested for total and bioavailable Cr in the soil and overlying vegetation via US EPA Methods 3050a (Total Cr) and 1311 (Total Characteristic Leaching Procedure, TCLP) (US EPA, 1995), respectively. The analysis of total and bioavailable Cr was used to assess the risk of nearby surface and groundwater contamination and to evaluate the site’s need for remediation. In addition, trends in soil Cr levels with respect to …

The White Dwarf Luminosity Function: The Shape Of Things To Come, Ted Von Hippel, M. Kilie, J. Munn, K. Williams, J. Libert, D. E. Winget, T. S. Metcalfe, Et Al.

Publications

We describe a new survey for cool white dwarfs that supplements Sloan Digital Sky Survey photometry with USNO proper motions and followup spectroscopy. To date we have discovered and spectroscopically confirmed 80 new moderate temperature and cool white dwarfs. We have also found a handful of high-velocity white dwarfs and we expect a sizable fraction of these to be thick disk or possibly halo objects. Our survey is designed to find 104 new white dwarfs, although only 60 will be among the faintest white dwarfs (MV 16), where most of the age-sensitivity resides. We discuss an extension of our survey …

Problems With The Dartmouth Wireless Snmp Data Collection, Tristan Henderson, David Kotz

Computer Science Technical Reports

The original Dartmouth wireless network study used SNMP to query the college's Cisco 802.11b access points. The perl scripts that performed the SNMP queries suffered from some problems, in that they queried inappropriate SNMP values, or misunderstood the meaning of other values. This data was also used in a subsequent analysis. The same scripts were used to collect data for a subsequent study of another wireless network. This document outlines these problems and indicates which of the data collected by the original scripts may be invalid.

Nanoscale Hydrophobic Interaction And Nanobubble Nucleation, T. Koishi, S. Yoo, K. Yasuoka, Xiao Cheng Zeng, T. Narumi, R. Susukita, A. Kawai, H. Furusawa, A. Suenaga, N. Okimoto, N. Futatsugi, T. Ebisuzaki

Xiao Cheng Zeng Publications

We report large-scale atomistic simulation of midrange nanoscale hydrophobic interaction, manifested by the nucleation of nanobubble between nanometer-sized hydrophobes at constrained equilibrium. When the length scale of the hydrophobes is greater than 2 nm, the nanobubble formation shows hysteresis behavior resembling the first-order transition. Calculation of the potential of mean force versus interhydrophobe distance provides a quantitative measure of the strength of the nanoscale hydrophobic interaction.

The Next Edition Of Iho-S-57 (4.0): A Primer, Lee Alexander

Center for Coastal and Ocean Mapping

The International Hydrographic Organization (IHO) is an intergovernmental consultative and technical organization that was established in 1921 to support the safety of navigation and the protection of the marine environment. IHO Special Publication 57 (IHO S-57) is the IHO Transfer Standard for Digital Hydrographic Data. It is the standard to be used for the exchange of digital hydrographic data between hydrographic offices (HOs), and for the distribution of hydrographic data to manufacturers, mariners and other data users (e.g., GIS). It was developed so that the transfer all forms of hydrographic data would take place in a consistent and uniform manner. …

2004 Scholars And Artists Bibliography, Michael Schwartz Library, Cleveland State University, Friends Of The Michael Schwartz Library

Scholars and Artists Bibliographies

This bibliography was created for the annual Friends of the Michael Schwartz Library Scholars and Artists Reception, recognizing scholarly and creative achievements of Cleveland State University faculty, staff and emeriti