Physical Sciences and Mathematics Commons^™

Longitudinal Emittance Blowup In The Large Hadron Collider, P. Baudrenghien, T. Mastoridis

Physics

The Large Hadron Collider (LHC) relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blowup provides the required emittance growth. The method was implemented through the summer of 2010. Band-limited RF phase-noise is injected in the main accelerating cavities during the whole ramp of about 11 min. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are …

Challenges In Estimating The Causal Effect Of An Intervention With Pre-Post Data (Part 1): Definition & Identification Of The Causal Parameter, Ann M. Weber, Mark J. Van Der Laan, Maya L. Petersen

U.C. Berkeley Division of Biostatistics Working Paper Series

There is mixed evidence of the effectiveness of interventions operating on a large scale. Although the lack of consistent results is generally attributed to problems of implementation or governance of the program, the failure to find a statistically significant effect (or the success of finding one) may be due to choices made in the evaluation. To demonstrate the potential limitations and pitfalls of the usual analytic methods used for estimating causal effects, we apply the first half of a roadmap for causal inference to a pre-post evaluation of a community-level, national nutrition program. Selection into the program was non-random and …

Distel: A Distributed El+ Ontology Classifier, Raghava Mutharaju, Pascal Hitzler, Prabhaker Mateti

Computer Science and Engineering Faculty Publications

OWL 2 EL ontologies are used to model and reason over data from diverse domains such as biomedicine, geography and road traffic. Data in these domains is increasing at a rate quicker than the increase in main memory and computation power of a single machine. Recent efforts in OWL reasoning algorithms lead to the decrease in classification time from several hours to a few seconds even for large ontologies like SNOMED CT. This is especially true for ontologies in the description logic EL⁺ (a fragment of the OWL 2 EL profile). Reasoners such as Pellet, Hermit, ELK etc. make …

Comparison Of Sontek Advocean-Hydras And Nortek Adv Vectors For Measuring Suspended Sediment Concentration Via Acoustic Backscatter, G. M. Cartwright, C. T. Friedrichs, R. Pico Vila, P. D. Panetta

Presentations

No abstract provided.

Aggregation, Pretransitional Behavior, And Optical Properties In The Isotropic Phase Of Lyotropic Chromonic Liquid Crystals Studied In High Magnetic Fields, T. Ostapenko, Y. A. Nastishin, Peter J. Collings, S. N. Sprunt, O D. Lavrentovich, J. T. Gleeson

Physics & Astronomy Faculty Works

We report results on the high-field magneto-optical response of four aqueous, lyotropic, chromonic liquid crystal formulations in the isotropic phase. Measurements of the field-induced birefringence at temperatures above the isotropic-nematic coexistence region at high magnetic fields reveal qualitative differences in different materials; these differences can be attributed to the nature of aggregation and are discussed within the context of competing aggregation models. Extending these measurements to very high fields and large optical phase differences reveals the presence of an unexpected optical phenomenon: magnetic field-induced circular birefringence, measured in the Voigt geometry, in a system containing no molecularly chiral species. Possible …

Stringsauto And Mapsss Results For Oaei 2013, Michelle Cheatham, Pascal Hitzler

Computer Science and Engineering Faculty Publications

StringsAuto and MapSSS are two closely related ontology alignment systems. The StringsAuto matcher seeks to explore the limits of a syntactic-only approach to alignment. The MapSSS system then expands on this work by embedding the syntactic matching of StringsAuto within a more complete alignment system that also makes use of semantic and structural information. In this paper we describe the basic operation of the two systems and discuss their performance in the OAEI 2013 evaluation.

Comprehensive Forensic Toxicological Analysis Of Designer Drugs, Madeleine Jean Swortwood

FIU Electronic Theses and Dissertations

New designer drugs are constantly emerging onto the illicit drug market and it is often difficult to validate and maintain comprehensive analytical methods for accurate detection of these compounds. Generally, toxicology laboratories utilize a screening method, such as immunoassay, for the presumptive identification of drugs of abuse. When a positive result occurs, confirmatory methods, such as gas chromatography (GC) or liquid chromatography (LC) coupled with mass spectrometry (MS), are required for more sensitive and specific analyses. In recent years, the need to study the activities of these compounds in screening assays as well as to develop confirmatory techniques to detect …

Multi-Level Surface Enhanced Raman Scattering Using AgoX Thin Film, Ming Lun Tseng, Chia Min Chang, Bo Han Cheng, Pin Chieh Wu, K. S. Chung, M. K. Hsiao, H. W. Huang, D. W. Huang, Hai-Pang Chiang, P.T. Leung, D. P. Tsai

Physics Faculty Publications and Presentations

Ag nanostructures with surface-enhanced Raman scattering (SERS) activities have been fabricated by applying laser-direct writing (LDW) technique on silver oxide (AgOx) thin films. By controlling the laser powers, multi-level Raman imaging of organic molecules adsorbed on the nanostructures has been observed. This phenomenon is further investigated by atomic-force microscopy and electromagnetic calculation. The SERS-active nanostructure is also fabricated on transparent and flexible substrate to demonstrate our promising strategy for the development of novel and low-cost sensing chip.

Cosm News, Georgia Southern University

College of Science and Mathematics News (2012-2019)

• COUR Fall 2013 Travel Awardees Announced

The Science And Psychology Of Survival, Thomas Kroll

Arboretum Lectures

Our brains and bodies are wired to survive-whether you are lost in the mountains, lost in a foreign city, or just feeling lost in a crowd. It's not about how many matches, maps, or knives you have, but how adaptable you are and how persistent you are about wanting to live.

Optimal Multi-Issue Negotiation In Open And Dynamic Environments, Fenghui Ren, Minjie Zhang

Dr Fenghui Ren

Multi-issue negotiations can lead negotiants to the “win-win” (optimal) outcomes which is not applicable in single issue negotiations. Negotiants’ preferences on all negotiated issues in multi-issue negotiations impact the negotiation results a lot. Most of existing multi-issue negotiation strategies are based on the situation that all negotiants have fixed preferences, and very little work has been done on situations when negotiants modify their preferences during the negotiation. However, as the negotiation environment becomes open and dynamic, negotiants may modify their preferences dynamic for higher profits. The motivation of this paper is to propose a novel optimal multi-issue negotiations approach to …

The Prediction Of Partners' Behaviors In Self-Interested Agents, Fenghui Ren, Minjie Zhang

Dr Fenghui Ren

No abstract provided.

Market-Driven Agents With Uncertain And Dynamic Outside Options, Fenghui Ren, Kwang Sim, Minjie Zhang

Dr Fenghui Ren

One of the most crucial criterion in automated negotiation is how to reach a consensus agreement for all negotiators under any negotiation environment. Currently, most negotiation strategies can work under the static environment only. This paper presents a model for designing negotiation agents that makes adjustable rates of concession by reacting to changing market situations with uncertain and dynamic outside options. This work is based on the model of market-driven agents (MDAs). To determine the amount of the concession for each trading cycle, these market-driven agents are guided by four mathematical functions of trading opportunity, trading competition, trading time and …

Prediction Of Partners' Behaviours In Agent Negotiation Under Open And Dynamic Environments, Fenghui Ren, Minjie Zhang

Dr Fenghui Ren

No abstract provided.

A Parallel, Multi-Issue Negotiation Model In Dynamic E-Markets, Fenghui Ren, Minjie Zhang, X. Luo, Danny Sutanto

Dr Fenghui Ren

No abstract provided.

Collaborative Agents For Complex Problems Solving, Minjie Zhang, Q. Bai, Fenghui Ren, John Fulcher

Dr Fenghui Ren

No abstract provided.

Coordinated Learning For Loosely Coupled Agents With Sparse Interactions, Chao Yu, Minjie Zhang, Fenghui Ren

Dr Fenghui Ren

No abstract provided.

A Market-Based Multi-Issue Negotiation Model Considering Multiple Preference In Dynamic E-Marketplaces, Fenghui Ren, Minjie Zhang, Chunyan Miao, Zhiqi Shen

Dr Fenghui Ren

Electronic commerce has been a significant commercial phenomenon in recent years and autonomous agents have made the advantages of e-markets more distinct. However, as e-market environments become open and dynamic, existing agent negotiation approaches expose some limitations. Static negotiation strategies and offer evaluation approaches might fail to capture dynamic changes of market situations, as well as changes of negotiators’ expectations on negotiation outcomes. When market situations change, agents may need modify their negotiation strategies, expectations and criteria on offer evaluations as well as counter-offer generations in order to maximize their profits. Furthermore, in multi-issue negotiations, agents may have multiple preferences, …

Exploiting Independent Relationships In Multiagent Systems For Coordinated Learning, Chao Yu, Minjie Zhang, Fenghui Ren

Dr Fenghui Ren

Creating coordinated multiagent policies in an environment with uncertainties is a challenging issue in the research of multiagent learning. In this paper, a coordinated learning approach is proposed to enable agents to learn both individual policies and coordinated behaviors by exploiting independent relationships inherent in many multiagent systems. We illustrate how this approach is employed to solve coordination problems in robot navigation domains. Experimental results of different scales of domains prove the effectiveness of our learning approach. 2012 Springer-Verlag.

Prediction Of Partners' Behaviors In Agent Negotiation Under Open And Dynamic Environments, Fenghui Ren, Minjie Zhang

Dr Fenghui Ren

Prediction of partners' behaviors in negotiation has been an active research direction in recent years in the area of multi-agent and agent system. So by employing the prediction results, agents can modify their own negotiation strategies in order to achieve an agreement much quicker or to look after much higher benefits. Even though some of prediction strategies have been proposed by researchers, most of them are based on machine learning mechanisms which require a training process in advance. However, in most circumstances, the machine learning approaches might not work well for some kinds of agents whose behaviors are excluded in …

A New Spreading Matrix For Block Spread Ofdm, Ibrahim S. Raad, Xiaojing Huang, Raad Raad

Dr Raad Raad

This paper presents a new spreading matrix for block spread OFDM (BSOFDM) to improve the performance of the system by increasing the correlation between the symbols. This is achieved by rotating the modulation scheme used at the transmission, say QPSK, into a higher order modulation scheme, for example 16QAM. By this the correlation between the transmitted symbols is increased. The advantage of this new spreading matrix over more traditional spreading matrices is its flexibility in achieving different higher order modulation schemes during transmission depending on the angle alpha. This is compared to other spreading matrices in frequency selective channel environment.

Neuro-Fuzzy Admission Control In Cellular Networks, Raad Raad, Ibrahim Raad

Dr Raad Raad

In this paper, a methodology is presented for designing an adaptive fuzzy logic controller based on neural networks. The neuro-fuzzy controller is first trained using data from an approximate analytical model of a cellular network then the controller is fine tuned and adapted to the unique cell dwell time and call holding time distributions of a particular cell in the network. Different cell dwell time distributions are considered for training the neuro-fuzzy controller. A neuro-fuzzy method that only relies on a limited amount of measured data for training purposes is also presented.

On The Energy Consumption Of Pure And Slotted Aloha Based Rfid Anti-Collision Protocols, Dheeraj Klair, Kwan-Wu Chin, Raad Raad

Dr Raad Raad

No abstract provided.

Mobile Ad-Hoc Network Key Management With Certificateless Cryptography, Zhenfei Zhang, Willy Susilo, Raad Raad

Dr Raad Raad

In this paper, we present an idea of adopting certificateless public key encryption (CL-PKE) schemes over mobile ad hoc network (MANET), which has not been explored before. In current literature, essentially there exists two main approaches, namely the public key cryptography and identity-based (ID-based) cryptography. Unfortunately, they both have some inherent drawbacks. In the public key cryptography system, a certificate authority (CA) is required to issue certificates between users' public keys and private keys to ensure their authenticity, whilst in an ID-based cryptography system, users' private keys are generated by a key generation center (KGC), which means the KGC knows …

A Spatially Aware Rfid-Enhanced Wireless Sensor Network, Dheeraj Klair, Kwan-Wu Chin, Raad Raad, Darryn Lowe

Dr Raad Raad

Radio frequency identification (RFID) systems are becoming increasingly popular for automatic object identification and supply chain management. Wide acceptance of this technology has led to several new areas of research, one of which is RFID-enhanced wireless sensor networks (WSNs). Such networks have the ability to self-organize, identify tagged objects, perform localization, and carry out searches; all of which are enablers of pervasive computing. This paper therefore presents various challenges to creating such networks, and describes our recent research on energy efficient RFID tag reading protocols.

Collaborative Research: Multiscale Analysis Of Geological Structures That Influence Crustal Seismic Anisotropy, Senthil Vel, Scott E. Johnson

University of Maine Office of Research Administration: Grant Reports

This project is a study of crustal material anisotropy with a focus on macroscale structural geometries and how they will modify the seismic response of rock fabrics. Seismic anisotropy is the cumulative interplay between propagating seismic waves and anisotropic earth material that manifests itself through the directional dependence of seismic wave speeds. Unraveling this effect in deformed crustal terranes is complex due to several factors, such as 3D geological geometry and heterogeneity, microscale fabric, bending of seismic raypaths due to velocity gradients, field experiments that may not offer full azimuthal coverage, and the observation of anisotropy as second-order waveform or …

The Role Of Cross-Shock Potential On Pickup Ion Shock Acceleration In The Framework Of Focused Transport Theory, Pingbing Zuo, Ming Zhang, Hamid K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

The focused transport theory is appropriate to describe the injection and acceleration of low-energy particles at shocks as an extension of diffusive shock acceleration (DSA). In this investigation, we aim to characterize the role of cross-shock potential (CSP) originated in the charge separation across the shock ramp on pickup ion (PUI) acceleration at various types of shocks with a focused transport model. The simulation results of energy spectrum and spatial density distribution for the cases with and without CSP added in the model are compared.With sufficient acceleration time, the focused transport acceleration finally falls into the DSA regime with the …

Discovery Of A New Tev Gamma-Ray Source: Ver J0521+211, P. T. Reynolds, Veritas

Physical Sciences Publications

We report the detection of a new TeV gamma-ray source, VER J0521+211, based on observations made with the VERITAS imaging atmospheric Cherenkov Telescope Array. These observations were motivated by the discovery of a cluster of >30 GeV photons in the first year of Fermi Large Area Telescope observations. VER J0521+211 is relatively bright at TeV energies, with a mean photon flux of (1.93 ± 0.13stat ± 0.78sys) × 10–11 cm–2 s–1 above 0.2 TeV during the period of the VERITAS observations. The source is strongly variable on a daily timescale across all wavebands, from optical to TeV, with a peak …

Photo-Orientation Of Liquid Crystals Due To Light-Induced Desorption And Adsorption Of Dye Molecules On An Aligning Surface, E. Ouskova, Yurii Reznikov, S. V. Shiyanovskii, L. Su, John L. West, O. V. Kuksenok, O. Francescangeli, F. Simoni

John L West

We show that adsorption of dye molecules control the light-induced alignment of dye-doped nematic liquid crystal (LC) on a nonphotosensitive polymer surface. The dependencies of light-induced twist structures on exposure, thermal baking, thickness, and aging before irradiation of the LC cells allowed us to propose the following mechanism for the alignment. Before irradiation, the “dark”-adsorbed layer on the tested surface is formed from dye molecules predominantly aligned along the initial direction of the director. Irradiation of the cell with linearly polarized light produces an additional layer with different orientational ordering of dye molecules. The final easy axis is determined by …

Organic Thin-Film Transistor-Driven Polymer-Dispersed Liquid Crystal Displays On Flexible Polymeric Substrates, C. D. Sheraw, L. Zhou, J. R. Huang, D. J. Gundlach, T. N. Jackson, M. G. Kane, I. G. Hill, M. S. Hammond, J. Campi, B. K. Greening, J. Franci, John L. West

John L West

We have fabricated organic thin-film transistor (OTFT)-driven active matrix liquid crystal displays on flexible polymeric substrates. These small displays have 16×16 pixel polymer-dispersed liquid crystal arrays addressed by pentacene active layer OTFTs. The displays were fabricated using a low-temperature process (<110 °C) on flexible polyethylene naphthalate film and are operated as reflective active matrix displays.