Physical Sciences and Mathematics Commons^™

Η Photoproduction On The Proton For Photon Energies From 0.75 To 1.95 Gev, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, S. Stepanyan, J. Yun, Et Al., Clas Collaboration

Physics Faculty Publications

Differential cross sections for γp→ηp have been measured with tagged real photons for incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information for protons scattered in the production process. The data provide the first extensive angular distribution measurements for the process above W = 1.75  GeV. Comparison with preliminary results from a constituent quark model support the suggestion that a third S₁₁ resonance with mass ∼1.8  GeV couples to the ηN channel.

Publisher's Note: Η Photoproduction On The Proton For Photon Energies From 0.75 To 1.95 Gev [Phys. Rev. Lett. 89, 222002 (2002)], M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, R. A. Niyazov, S. Stepanyan, L. B. Weinstein, Et Al., Clas Collaboration

Physics Faculty Publications

No abstract provided.

First Measurement Of The Double Spin Asymmetry In →E→P → E ‘Π⁺ In The Resonance Region, G. E. Dodge, K. V. Dharmawardane, T. A. Forest, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, R. A. Niyazov, L. B. Weinstein, J. Yun, Et. Al., Clas Collaboration

Physics Faculty Publications

The double spin asymmetry in the ^→e^→p → e' π⁺n reaction has been measured for the first time in the resonance region for four-momentum transfer Q² = 0.35-1.5 GeV². Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH₃ target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with Q^{2 …}

Synchronization Of The Human Cortical Working Memory Network, Sharlene Newman, Marcel Just, Patricia Carpenter

Marcel Adam Just

No abstract provided.

Handbook On Fence Viewers And Laws On Fences In The Commonwealth Of Massachusetts, Joseph Larson

Joseph S. Larson

This handbook is intended to serve as an informal guide to the laws that pertain to Fence Viewers and fencing in general in the Commonwealth of Massachusetts. We have used two primary sources for the current Massachusetts laws. We first searched the unofficial on-line text of the Massachusetts General Laws provided on the Internet (http://www.state.ma.us/legis/laws/mgl/) by the State Senate. This was followed by an examination of the laws, court decisions and notes as they appear in the most recent volumes and annual supplements of Massachusetts General Laws Annotated (1977). In every instance, the text describing each law consists only of …

Optimal Policies For Investment With Time-Varying Return Distributions, Douglas Steigerwald, Doncho Donchev, Svetlozar Rachev

Douglas G. Steigerwald

We develop a model in which investors must learn the distribution of asset returns over time. The process of learning is made more difficult by the fact that the distributions are not constant through time. We consider risk-neutral investors who have quadratic utility and are selecting between two risky assets. We determine the time at which it is optimal to update the distribution estimate and, hence, alter portfolio weights. Our results deliver an optimal policy for asset allocation, that is, the sequence of time intervals at which it is optimal to switch between assets, based on stochastic optimal control theory. …

Wide Plate Margin Deformation, Southern Central America And Northwestern South America, Casa Gps Observations, James Kellogg

James N Kellogg

Global Positioning System (GPS) data from southern Central America and northwestern South America were collected during 1991, 1994, 1996, and 1998 in Costa Rica, Panama, Ecuador, Colombia and Venezuela. These data reveal wide plate boundary deformation and escape tectonics occurring along an approximately 1400 km length of the North Andes; locking of the subducting Nazca plate and strain accumulation in the Ecuador-Colombia forearc; ongoing collision of the Panama arc and Colombia; and convergence of the Caribbean plate with Panama and South America. Elastic modeling of observed horizontal displacements in the Ecuador forearc is consistent with partial locking (50%) in the …

Sustainable Versus Unsustainable Propositions, John Dernbach

John C. Dernbach

No abstract provided.

Mathematical Models In Biology, Borbala Mazzag

Borbala Mazzag

No abstract provided.

On The Convergence Of Puck Clustering Systems, S. Kazadi, A. Abdul-Khaliq, R. Goodman

Sanza Kazadi

Asymptotically Constant Solutions Of Functional Difference Systems, William F. Trench

William F. Trench

No abstract provided.

Analysis And Classification Of Nonlinear Dispersive Evolution Equations In The Potential Representation, Andrei Ludu

Andrei Ludu

No abstract provided.

Dimensionality-Reducing Expansion, Boundary Type Quadrature Formulas, And The Boundary Element Method, Tian-Xiao He

Tian-Xiao He

This paper discusses the connection between boundary quadrature formulas constructed by using solutions of partial differential equations and boundary element schemes.

Features For Word Spotting In Historical Manuscripts, Toni M. Rath, R. Manmatha

R. Manmatha

For the transition from traditional to digital libraries, the large number of handwritten manuscripts that exist pose a great challenge. Easy access to such collections requires an index, which is currently created manually at great cost. Because automatic handwriting recognizers fail on historical manuscripts, the word spotting technique has been developed: the words in a collection are matched as images and grouped into clusters which contain all instances of the same word. By annotating ``interesting clusters," an index that links words to the locations where they occur can be built automatically.

Due to the noise in historical documents, selecting the …

What Do We Learn From The Local Geometry Of Glass-Forming Liquids?, Francis W. Starr, S. Sastry, J. F. Douglas, S. C. Glotzer

Francis Starr

No abstract provided.

Word Image Matching Using Dynamic Time Warping, Toni M. Rath, R. Manmatha

R. Manmatha

Libraries and other institutions are interested in providing access to scanned versions of their large collections of handwritten historical manuscripts on the web or on CDROMs. Providing convenient access to a collection requires an index which is manually created at great labour and expense. Since current handwriting recognizers do not perform well on historical documents, a technique called word spotting has been developed. It addresses the need for indexing single-author handwritten historical manuscripts in a new way: word images are matched to form clusters which contain occurrences of the same word throughout a collection. By annotating ``interesting" clusters, an index …

A Formal Approach To Score Normalization For Metasearch, H. Sever, R. Manmatha

R. Manmatha

Meta-search, or the combination of the outputs of different search engines in response to a query, has been shown to improve performance. Since the scores produced by different search engines are not comparable, researchers have often decomposed the metasearch problem into a score normalization step followed by a combination step. Combination has been studied by many researchers. While appropriate normalization can affect performance, most of the normalization schemes suggested are ad hoc in nature.

In this paper, we propose a formal approach to normalizing scores for meta-search by taking the distributions of the scores into account. Recently, it has been …

A Critical Examination Of Tdt’S Cost Function, R. Manmatha, Ao Feng, James Allan

R. Manmatha

Topic Detection and Tracking (TDT) tasks are evaluated using a cost function. The standard TDT cost function assumes a constant probability of relevance P(rel) across all topics. In practice, P(rel) varies widely across topics. We argue using both theoretical and experimental evidence that the cost function should be modified to account for the varying P(rel).

The Single Particle Potential In Mean-Field Theory, Peter Palffy-Muhoray

Peter Palffy-Muhoray

The problem of determining the single particle energy in a mean-field description of interacting particles is considered. It is shown that the single particle energy must satisfy two consistency conditions, and a general procedure for obtaining the single particle energy from the pair energy is proposed. Interacting dipolar systems are examined, current approaches in the literature are discussed, and the usefulness of the proposed method is demonstrated.

Translational And Rotational Diffusion In Stretched Water, P. A. Netz, Francis Starr, M. C. Barbosa, H. E. Stanley

Francis Starr

No abstract provided.

Indexing For A Digital Library Of George Washington’S Manuscripts: A Study Of Word Matching Techniques, T. M. Rath, S. Kane, A. Lehman, E. Partridge, R. Manmatha

R. Manmatha

In a multimedia world, one would like electronic access to all kinds of information. But a lot of important information still only exists on paper and it is a challenge to efficiently access or navigate this information even if it is scanned in. The previously proposed \word spotting" idea is an approach for accessing and navigating a collection of handwritten documents available as images using an index automatically generated by matching words as pictures. The most difficult task in solving this problem is the matching of word images. The quality of the aged documents and the variations in handwriting make …

Bismuth Triflate Catalyzed Allylation Of Acetals: A Simple And Mild Method For Synthesis Of Homoallyl Ethers, Ram S. Mohan, Laura C. Wieland, Herbert M. Zerth

Ram S. Mohan

Applications Of Bismuth(Iii) Compounds In Organic Synthesis, Ram S. Mohan, Nicholas M. Leonard, Laura C. Wieland

Ram S. Mohan

No abstract provided.

Targets, Timetables And Effective Implementing Mechanisms: Necessary Building Blocks For Sustainable Development, John C. Dernbach

John C. Dernbach

No abstract provided.

An Experimental Study Of Grain Scale Melt Segregation Mechanisms In Two Common Crustal Rock Types, Caleb W. Holyoke Iii, Tracy Rushmer

Caleb Holyoke

No abstract provided.

Forecasting Volatility In European Stock Markets With Non-Linear Garch Models, Giancarlo Forte, Matteo Manera

Matteo Manera

This paper investigates the forecasting performance of three popular variants of the nonlinear GARCH models, namely VS-GARCH, GJR-GARCH and Q-GARCH, with the symmetric GARCH(1,1) model as a benchmark. The application involves ten European stock price indexes. Forecasts produced by each non-linear GARCH model and each index are evaluated using a common set of classical criteria, as well as forecast combination techniques with constant and non-constant weights. With respect to the standard GARCH specification, the non-linear models generally lead to better forecasts in terms of both smaller forecast errors and lower biases. In-sample forecast combination regressions are better than those from …

Sustainable Development: Now More Than Ever, John C. Dernbach

John C. Dernbach

This Article explains how and why sustainable development emerged as a conceptual framework, the basic concepts or principles on which this framework is based, why sustainability is primarily a matter for domestic national governance, and why the United States needs to play a leading role in fostering sustainable development. Because "sustainable" modifies "development," it is first important to understand what development means. Since the end of World War II, development has included at least four related elements: peace and security, economic development, social development, and supportive national governance. Each element is reflected in major multilateral treaties that provide a common …

Synthesis And Physico-Chemical Investigations On 16 And 18 Membered [N4] Macrocycles Modified With Appropriate Carbonyl Functions - A Closer Mimic To A Synthetic Cyclic Tetrapeptide; Isolation Of Stable Encapsulated Derivatives With Zn(Ii),Cd(Ii) And Hg(Ii) Ions, Z. A. Siddiqi, V. J. Mathew, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

Reaction of 1, 2-diamine or 1,3-diamine with succinic/ phthalic anhydride in 1:1 molar ratio at RT in dioxane results in 16-membered or 18 membered macrocycle which posseses tetraamide/ tetrapeptide functions in the molecular unit which however, exhibit ample reactivity towards metallic substrates affording stable compounds with [MLX2 ] (M=Zn,Cd or Hg; X = CI, SCN or CI04 ) stoichiometry as evidenced from the physico-chemical investigations which confirm that the macrocyclic moieties (L| - L6 ) have the appropriate cavity sizes to encapsulate Zn(II), Cd (II) or Hg(II) ions via coordination through nitrogens of the amide/ peptide functions in tetradentate fashion …

Candidate Set Strategies For Ant Colony Optimisation, Marcus Randall, James Montgomery

Marcus Randall

Ant Colony Optimisation based solvers systematically scan the set of possible solution elements before choosing a particular one. Hence, the computational time required for each step of the algorithm can be large. One way to overcome this is to limit the number of element choices to a sensible subset, or candidate set. This paper describes some novel generic candidate set strategies and tests these on the travelling salesman and car sequencing problems. The results show that the use of candidate sets helps to find competitive solutions to the test problems in a relatively short amount of time.