Physical Sciences and Mathematics Commons^™

B. The Signing Of The Constitution Of The Pacific Polymer Federation, Otto Vogl

Otto Vogl

The Constitution of the Pacific Polymer Federation was signed on October 19, 1987 in Tokyo, Japan at the Inter-national House in Roppongi, Tokyo by the Chairman of the ACS Division of Polymer Chemistry, S, R. Eby, and the Chair-man of the Foreign Affairs Committee, O. Vogl; by the President of the Society of Polymer Science Japan, M. Takayanagi; Chairman and Vice President for International Affairs, A. Abe. For the Polymer Division of the Royal Aus-tralian Institute of Chemistry, Chairman D.J.T. Hill and Chair-man of the International Committee, J.H. O'Donnell signed the Constitution.

C. Pacific Polymer Federation Presidents, Otto Vogl

Otto Vogl

Names and photographs of the presidents of the Pacific Polymer Federation.

“Strong Feedbacks Between Hydrology And Sliding Of A Small Alpine Glacier.”, Kelly R. Macgregor, R.S. Anderson, S.P. Anderson, E.D. Waddington, S. O’Neel, C.A. Riihimaki, M.G. Loso

Kelly R. MacGregor

No abstract provided.

Swarming Patterns In A Two-Dimensional Kinematic Model For Biological Groups, Chad M. Topaz, Andrea L. Bertozzi

Chad M. Topaz

We construct a continuum model for the motion of biological organisms experiencing social interactions and study its pattern-forming behavior. The model takes the form of a conservation law in two spatial dimensions. The social interactions are modeled in the velocity term, which is nonlocal in the population density and includes a parameter that controls the interaction length scale. The dynamics of the resulting partial integrodifferential equation may be uniquely decomposed into incompressible motion and potential motion. For the purely incompressible case, the model resembles one for fluid dynamical vortex patches. There exist solutions which have constant population density and compact …

Multifrequency Control Of Faraday Wave Patterns, Chad M. Topaz, Jeff Porter, Mary Silber

Chad M. Topaz

We show how pattern formation in Faraday waves may be manipulated by varying the harmonic content of the periodic forcing function. Our approach relies on the crucial influence of resonant triad interactions coupling pairs of critical standing wave modes with damped, spatiotemporally resonant modes. Under the assumption of weak damping and forcing, we perform a symmetry-based analysis that reveals the damped modes most relevant for pattern selection, and how the strength of the corresponding triad interactions depends on the forcing frequencies, amplitudes, and phases. In many cases, the further assumption of Hamiltonian structure in the inviscid limit determines whether the …

Pattern Control Via Multi-Frequency Parametric Forcing, Jeff Porter, Chad M. Topaz, Mary Silber

Chad M. Topaz

We use symmetry considerations to investigate control of a class of resonant three-wave interactions relevant to pattern formation in weakly damped, parametrically forced systems near onset. We classify and tabulate the most important damped, resonant modes and determine how the corresponding resonant triad interactions depend on the forcing parameters. The relative phase of the forcing terms may be used to enhance or suppress the nonlinear interactions. We compare our symmetry-based predictions with numerical and experimental results for Faraday waves. Our results suggest how to design multifrequency forcing functions that favor chosen patterns in the lab.

The Nature Of Radio Continuum Emission In The Dwarf Starburst Galaxy Ngc 625, John M. Cannon, E. D. Skillman

John Cannon

No abstract provided.

Hi Observations Of The Local Group Dwarf Wlm, D. Jackson, E. D. Skillman, John M. Cannon, S. Cote

John Cannon

No abstract provided.

Proton Source Size Measurements In The Ea -> E(')Ppx Reaction, Av Stavinsky, Kr Mikhailov, R Lednicky, Av Vlassov, G Adams, P Ambrozewich, E Anciant, M Anghinolfi, B Asavapibhop, G Asryan, G Audit, T Auger, H Avakian, H Bagdasaryan, Jp Ball, S Barrow, V Batourine, M Battaglieri, K Beard, M Bektasoglu, M Bellis, N Benmouna, N Bianchi, As Biselli, S Boiarinov, Be Bonner, S Bouchigny, R Bradford, D Branford, Wk Brooks, Vd Burkert, C Butuceanu, Jr Calarco, Ds Carman, C Cetina, S Chen, Pl Cole, D Cords, A Coleman, P Corvisiero, D Crabb, Jp Cummings, N Dashyan, Ed Sanctis, Rd Vita, Pv Degtyarenko, H Denizli, L Dennis, A Deur, Kv Dharmawardane, C Djalali, Ge Dodge, D Doughty, P Dragovitsch, M Dugger, S Dytman, Op Dzyubak, H Egiyan, Ks Egiyan, L Elouadrhiri, A Empl, P Eugenio, R Fatemi, Rg Fersch, Rj Feuerbach, Ta Forest, H Funsten, M Garcon, G Gavalian, S Gilad, Gp Gilfoyle, Kl Giovanetti, P Girard, Cio Gordon, Rw Gothe, K Griffioen, M Guidal, M Guillo, N Guler, L Guo, V Gyurjyan, C Hadjidakis, Rs Hakobyan, J Hardie, D Heddle, Fw Hersman, K Hicks, I Hleiqawi, M Holtrop, J Hu, Ce Hyde-Wright, Dg Ireland, Mm Ito, D Jenkins, K Joo, Hg Juengst, Jh Kelley, Jd Kellie, M Khandaker, Dh Kim, Ky Kim, K Kim, Ms Kim, W Kim, A Klein, Fj Klein, Av Klimenko, M Klusman, Mv Kossov, Lh Kramer, V Kubarovski, Se Kuhn, J Kuhn, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, Ga Leksin, T Lee, J Li, K Livingston, K Lukashin, Jj Manak, C Marchand, S Mcaleer, Jwc Mcnabb, Ba Mecking, S Mehrabyan, Jj Melone, Md Mestayer, Ca Meyer, M Mirazita, R Miskimen, V Mokeev, L Morand, Sa Morrow, V Muccifora, J Mueller, Gs Mutchler, J Napolitano, R Nasseripour, So Nelson, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, Ra Niyazov, M Nozar, Gv O'Rielly, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, G Peterson, Sa Philips, Na Pivnyuk, D Pocanic, O Pogorelko, E Polli, S Pozdniakov, Bm Preedom, Jw Price, Y Prok, D Protopopescu, Lm Qin, Ba Raue, G Riccardi, G Ricco, M Ripani, Bg Ritchie, F Ronchetti, G Rosner, P Rossi, D Rowntree, Pd Rubin, F Sabatie, K Sabourov, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, Yg Sharabian, J Shaw, S Simionatto, Av Skabelin, Es Smith, Lc Smith, Di Sober, M Spraker, S Stepanyan, Ss Stepanyan, Be Stokes, P Stoler, Ii Strakovsky, M Taiuti, S Taylor, Dj Tedeschi, U Thoma, R Thompson, A Tkabladze, L Todor, C Tur, M Ungaro, Mf Vineyard, Ls Vorobeyev, K Wang, Lb Weinstein, H Weller, Dp Weygand, Cs Whisnant, M Williams, E Wolin, Mh Wood, A Yegneswaran, J Yun, L Zana

Michael Williams

Two-proton correlations at small relative momentum q were studied in the eA(3He,4He,C,Fe)-->e(')ppX reaction at E(0)=4.46 GeV using the CLAS detector at Jefferson Lab. The enhancement of the correlation function at small q was found to be in accordance with theoretical expectations. Sizes of the emission region were extracted, and proved to be dependent on A and on the proton momentum. The size of the two-proton emission region for He was measured in eA reactions for the first time.

Complete Measurement Of Three-Body Photodisintegration Of He-3 For Photon Energies Between 0.35 And 1.55 Gev, S Niccolai, G Audit, Bl Berman, Jm Laget, S Strauch, G Adams, A Afanasev, P Ambrozewicz, M Anghinolfi, Jrm Annand, C Armstrong, B Asavapibhop, H Avakian, H Bagdasaryan, Jp Ball, S Barrow, M Battaglieri, K Beard, M Bektasoglu, M Bellis, N Benmouna, N Bianchi, As Biselli, S Boiarinov, Be Bonner, S Bouchigny, R Bradford, D Branford, Wj Briscoe, Wk Brooks, Vd Burkert, C Butuceanu, Jr Calarco, Ds Carman, B Carnahan, S Chen, Pl Cole, A Coleman, D Cords, P Corvisiero, D Crabb, H Crannell, Jp Cummings, E De Sanctis, R Devita, Pv Degtyarenko, H Denizli, L Dennis, Kv Dharmawardane, Ks Dhuga, C Djalali, Ge Dodge, D Doughty, P Dragovitsch, M Dugger, S Dytman, Op Dzyubak, H Egiyan, Ks Egiyan, L Elouadrhiri, A Empl, R Ent, P Eugenio, R Fatemi, G Fedotov, G Feldman, Rj Feuerbach, J Ficenec, Ta Forest, H Funsten, G Gavalian, Gp Gilfoyle, Kl Giovanetti, E Golovatch, Cio Gordon, Rw Gothe, K Griffioen, M Guidal, M Guillo, N Guler, L Guo, V Gyurjyan, C Hadjidakis, Rs Hakobyan, J Hardie, D Heddle, P Heimberg, Fw Hersman, K Hicks, K Hleiqawi, M Holtrop, J Hu, M Huertas, Ce Hyde-Wright, Yy Ilieva, D Ireland, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, J Kellie, M Khandaker, Ky Kim, K Kim, W Kim, A Klein, Fj Klein, Av Klimenko, M Klusman, M Kossov, Lh Kramer, Y Kuang, Se Kuhn, J Kuhn, J Lachniet, J Langheinrich, D Lawrence, J Li, Acs Lima, K Livingston, K Lukashin, Jj Manak, C Marchand, S Mcaleer, Jwc Mcnabb, Ba Mecking, Jj Melone, Md Mestayer, Ca Meyer, K Mikhailov, R Minehart, M Mirazita, R Miskimen, L Morand, Sa Morrow, V Muccifora, J Mueller, Ly Murphy, Gs Mutchler, J Napolitano, R Naseripour, G Niculescu, I Niculescu, Bb Niczyporuk, Ra Niyazov, M Nozar, Jt O'Brien, Gv O'Rielly, M Osipenko, A Ostrovidov, K Park, E Pasyuk, Sa Philips, N Pivnyuk, D Pocanic, O Pogorelko, E Polli, I Popa, S Pozdniakov, Bm Preedom, Jw Price, Y Prok, D Protopopescu, Lm Qin, Ba Raue, G Riccardi, G Ricco, M Ripani, Bg Ritchie, F Ronchetti, G Rosner, P Rossi, D Rowntree, Pd Rubin, F Sabatie, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, A Shafi, Yg Sharabian, J Shaw, Av Skabelin, Es Smith, Lc Smith, Di Sober, A Stavinsky, S Stepanyan, P Stoler, Ii Strakovsky, R Suleiman, M Taiuti, S Taylor, Dj Tedeschi, U Thoma, R Thompson, R Tkabladze, L Todor, C Tur, M Ungaro, Mf Vineyard, Av Vlassov, K Wang, Lb Weinstein, Dp Weygand, Cs Whisnant, M Williams, E Wolin, Mh Wood, A Yegneswaran, J Yun, L Zana

Michael Williams

The three-body photodisintegration of 3He has been measured with the CLAS detector at Jefferson Lab, using tagged photons of energies between 0.35 GeV and 1.55 GeV. The large acceptance of the spectrometer allowed us for the first time to cover a wide momentum and angular range for the two outgoing protons. Three kinematic regions dominated by either two- or three-body contributions have been distinguished and analyzed. The measured cross sections have been compared with results of a theoretical model, which, in certain kinematic ranges, have been found to be in reasonable agreement with the data.

Confidence Estimation For Information Extraction, Aron Culotta, Andrew Mccallum

Andrew McCallum

Information extraction techniques automatically create structured databases from unstructured data sources, such as the Web or newswire documents. Despite the successes of these systems, accuracy will always be imperfect. For many reasons, it is highly desirable to accurately estimate the confidence the system has in the correctness of each extracted field. The information extraction system we evaluate is based on a linear-chain conditional random field (CRF), a probabilistic model which has performed well on information extraction tasks because of its ability to capture arbitrary, overlapping features of the input in a Markov model. We implement several techniques to estimate the …

Sign Detection In Natural Images With Conditional Random Fields, Jerod Weinman, Allen Hanson, Andrew Mccallum

Andrew McCallum

Traditional generative Markov random fields for segmenting images model the image data and corresponding labels jointly, which requires extensive independence assumptions for tractability. We present the conditional random field for an application in sign detection, using typical scale and orientation selective texture filters and a nonlinear texture operator based on the grating cell. The resulting model captures dependencies between neighboring image region labels in a data-dependent way that escapes the difficult problem of modeling image formation, instead focusing effort and computation on the labeling task. We compare the results of training the model with pseudo-likelihood against an approximation of the …

Table Extraction For Answer Retrieval, Xing Wei, Bruce Croft, Andrew Mccallum

Andrew McCallum

The ability to find tables and extract information from them is a necessary component of question answering and other information retrieval tasks. Documents often contain tables in order to communicate densely packed, multidimensional information. Tables do this by employing layout patterns to efficiently indicate fields and records in two-dimensional form. Their rich combination of formatting and content present difficulties for traditional retrieval techniques. This paper describes techniques for extracting tables from text and retrieving answers from the extracted information. We compare machine learning (especially conditional random fields) and heuristic methods for table extraction. Our approach creates a cell document, which …

Interactive Information Extraction With Constrained Conditional Random Fields, Trausti Kristjansson, Aron Culotta, Paul Viola, Andrew Mccallum

Andrew McCallum

Information Extraction methods can be used to automatically "fill-in" database forms from unstructured data such as Web documents or email. State-of-the-art methods have achieved low error rates but invariably make a number of errors. The goal of an Interactive Information Extraction system is to assist the user in filling in database fields while giving the user confidence in the integrity of the data. The user is presented with an interactive interface that allows both the rapid verification of automatic field assignments and the correction of errors. In cases where there are multiple errors, our system takes into account user corrections, …

Uniqueness Theorems In Bioluminescence Tomography, Ge Wang, Yi Li, Ming Jiang

Yi Li

Motivated by bioluminescent imaging needs for studies on gene therapy and other applications in the mouse models, a bioluminescence tomography (BLT) system is being developed in the University of Iowa. While the forward imaging model is described by the well-known diffusion equation, the inverse problem is to recover an internal bioluminescent source distribution subject to Cauchy data. Our primary goal in this paper is to establish the solution uniqueness for BLT under practical constraints despite the ill-posedness of the inverse problem in the general case. After a review on the inverse source literature, we demonstrate that in the general case …

Piecewise Training With Parameter Independence Diagrams: Comparing Globally- And Locally-Trained Linear-Chain Crfs, Andrew Mccallum, Charles Sutton

Andrew McCallum

We present a diagrammatic formalism and practial methods for introducing additional independence assumptions into parameter estimation, enabling efficient training of undirected graphical models in locally-normalized pieces. On two real-world data sets we demonstrate our locally-trained linear-chain CRFs outperforming traditional CRFs--training in less than one-fifth the time, and providing a statistically-significant gain in accuracy.

An Exploration Of Entity Models, Collective Classification And Relation Description, Hema Raghavan, James Allan, Andrew Mccallum

Andrew McCallum

Traditional information retrieval typically represents data using a bag of words; data mining typically uses a highly structured database ontology. This paper explores the a middle ground we term entity models, in which questions about structured data may be posed and answered, but the complexities and task-specific restrictions of ontologies are avoided. An entity model is a language model or word distribution associated with an entity, such as a person, place or organization. Using these per-entity language models, entities may be clustered, links may be detected or described with a short summary, entities may be collectively classified, and question answering …

Collective Segmentation And Labeling Of Distant Entities In Information Extraction, Charles Sutton, Andrew Mccallum

Andrew McCallum

In information extraction, we often wish to identify all mentions of an entity, such as a person or organization. Traditionally, a group of words is labeled as an entity based only on local information. But information from throughout a document can be useful; for example, if the same word is used multiple times, it is likely to have the same label each time. We present a CRF that explicitly represents dependencies between the labels of pairs of similar words in a document. On a standard information extraction data set, we show that learning these dependencies leads to a 13.7% reduction …

Classification Models For New Event Detection, Girdhar Kumaran, James Allan, Andrew Mccallum

Andrew McCallum

New event detection (NED) involves monitoring news streams to detect the stories that report on new events. In this paper we explore the application of machine learning classification techniques for this task. We introduce the concept of triangulation with illustrative examples. We develop new features that build on this concept, and the named entities present in a document. The classifiers we developed showed significant and consistent improvement over the baseline vector space model system, on all the collections we tested on. Analysis of the performance of our classifiers suggests the utility of named entities, and the applicability of machine learning …

Accurate Information Extraction From Research Papers Using Conditional Random Fields, Fuchun Peng, Andrew Mccallum

Andrew McCallum

With the increasing use of research paper search engines, such as CiteSeer, for both literature search and hiring decisions, the accuracy of such systems is of paramount importance. This paper employs Conditional Random Fields (CRFs) for the task of extracting various common fields from the headers and citation of research papers. The basic theory of CRFs is becoming well-understood, but best-practices for applying them to real-world data require additional exploration. This paper makes an empirical exploration of several factors, including variations on Gaussian, exponential and hyperbolic-L1 priors for improved regularization, and several classes of features and Markov order. On a …

A Note On Semi-Supervised Learning Using Markov Random Fields, Wei Li, Andrew Mccallum

Andrew McCallum

This paper describes conditional-probability training of Markov random fields using combinations of labeled and unlabeled data. We capture the similarities between instances learning the appropriate distance metric from the data. The likelihood model and several training procedures are presented.

Chinese Segmentation And New Word Detection Using Conditional Random Fields, Fuchun Peng, Fangfang Feng, Andrew Mccallum

Andrew McCallum

Chinese word segmentation is a difficult, important and widely-studied sequence modeling problem. This paper demonstrates the ability of linear-chain conditional random fields (CRFs) to perform robust and accurate Chinese word segmentation by providing a principled framework that easily supports the integration of domain knowledge in the form of multiple lexicons of characters and words. We also present a probabilistic new word detection method, which further improves performance. Our system is evaluated on four datasets used in a recent comprehensive Chinese word segmentation competition. State-of-the-art performance is obtained.

A Counterexample In Sturm-Liouville Completeness Theory, Paul Binding, Branko Ćurgus

Mathematics Faculty Publications

We give an example of an indefinite weight Sturm-Lionville problem whose eigenfunctions form a Riesz basis under Dirichlet boundary conditions but not under anti-periodic boundary conditions.

A Contraction Of The Lucas Polygon, Branko Ćurgus

Mathematics Faculty Publications

The celebrated Gauss-Lucas theorem states that all the roots of the derivative of a complex non-constant polynomial p lie in the convex hull of the roots of p, called the Lucas polygon of p. We improve the Gauss-Lucas theorem by proving that all the nontrivial roots of p^' lie in a smaller convex polygon which is obtained by a strict contraction of the Lucas polygon of p.

An Inverse Problem For The Transport Equation In The Presence Of A Riemannian Metric, Stephen R. Mcdowall

Mathematics Faculty Publications

The stationary linear transport equation models the scattering and absorption of a low-density beam of neutrons as it passes through a body. In Euclidean space, to a first approximation, particles travel in straight lines. Here we study the analogous transport equation for particles in an ambient field described by a Riemannian metric where, again to first approximation, particles follow geodesics of the metric. We consider the problem of determining the scattering and absorption coefficients from knowledge of the albedo operator on the boundary of the domain. Under certain restrictions, the albedo operator is shown to determine the geodesic ray transform …

Optical Design Of Two-Reflector Systems, The Monge-Kantorovich Mass Transfer Problem And Fermat’S Principle, Tilmann Glimm, Vladimir Oliker

Mathematics Faculty Publications

It is shown that the problem of designing a two-reflector system transforming a plane wave front with given intensity into an output plane front with prescribed output intensity can be formulated and solved as the Monge-Kantorovich mass transfer problem.

Numbers In The Sky(Viewing Sculpture), Branko Ćurgus

Mathematics Faculty Publications

The following is my personal exploration of Noguchi’s sculpture inspired by what I do most of the time: math, or playing with numbers. His sculpture is very geometric; it lends itself to mathematical explorations, and I decided to look for a mathematical message in it.

I think Skyviewing Sculpture is really beautiful, and I have also encountered a lot of beautiful things in math, so the natural thing was to look for a connection: the beautiful sculpture giving rise to beautiful math. This is a short report of what I found. There is much more to be discovered, and these …

A Quasi-Linear Manifolds And Quasi-Linear Mapping Between Them, Aki̇f Abbasov

Turkish Journal of Mathematics

In this article a special class of Banach manifolds (called QL-manifolds) and mapping between them (QL-mappings) are introduced and some examples are given.

On Graded Primary Ideals, Mashhoor Refai, Khaldoun Al-Zoubi

Turkish Journal of Mathematics

Let G be a group and R be a G-graded commutative ring, i.e., R = \oplus_{g \in G} R_g and R_gR_h \subseteq R_{gh} for all g, h \in G. In this paper, we study the graded primary ideals and graded primary G-decomposition of a graded ideal.

Determination Of A Fractional-Linear Pencil Of Sturm-Liouville Operators By Two Of Its Spectra, R. T. Pashayev

Turkish Journal of Mathematics

In this paper we consider the Sturm-Liouville equations on a finite interval which is fractional-linear in the spectral parameter. The inverse spectral problem consisting of the recovering of the operator from the two spectra is investigated and a uniqueness theorem for solution of the inverse problem is proved.