Physical Sciences and Mathematics Commons^™

Sptizer And Jcmt Observations Of The Active Galactic Nucleus In The Sombrero Galaxy (Ngc 4594), G. J. Bendo, B. A. Buckalew, D. A. Dale, B. T. Draine, R. D. Joseph, R. C. Kennicutt, K. Sheth, J.D. T. Smith, F. Walter, D. Calzetti, John M. Cannon, C. W. Engelbracht, K. D. Gordon, G. Helou, D. Hollenbach, E. J. Murphy, H. Roussel

John Cannon

No abstract provided.

Hot Dust And Pah Emission At Low Metallicity: A Spitzer Survey Of Local Group And Other Nearby Dwarf Galaxies, D. C. Jackson, John M. Cannon, E. D. Skillman, H. Lee, R. D. Gehrz, C. E. Woodward, E. Polomski

John Cannon

No abstract provided.

On Extending The Mass-Metallicity Relation Of Galaxies By 2.5 Decades In Stellar Mass, H. Lee, E. D. Skillman, John M. Cannon, D. C. Jackson, R. D. Gehrz, E. F. Polomski, C. E. Woodward

John Cannon

No abstract provided.

An Initial Look At The Far Infrared-Radio Correlation Within Nearby Star-Forming Galaxies Using The Spitzer Space Telescope, E. J. Murphy, R. Braun, G. Helou, L. Armus, J.D. P. Kenney, K. D. Gordon, G. J. Bendo, D. A. Dale, F. Walter, T. A. Oosterloo, R. C. Kennicutt, D. Calzetti, John M. Cannon, B. T. Draine, C. W. Engelbracht, D. J. Hollenbach, T. H. Jarrett, L. J. Kewley, C. Leitherer, A. Li, M. J. Meyer, M. W. Regan, G. H. Rieke, M. J. Rieke, H. Roussel, K. Sheth, J.D. T. Smith, M. D. Thornley

John Cannon

No abstract provided.

The Nature Of Infrared Emission In The Local Group Dwarf Galazy Ncg 6822 As Revealed By Spitzer, John M. Cannon, F. Walter, L. Armus, G. J. Bendo, D. Calzetti, B. T. Draine, C.W. Engelbracht, G. Helou, R. C. Kennicutt, C. Leitherer, H. Roussel, C. Bot, B. Buckalew, D. A. Dale, W. J.G. Deblok, K. D. Gordon, D. J. Hollenbach, T. H. Jarrett, M. J. Meyer, E. J. Murphy, K. Sheth, M. D. Thornley

John Cannon

No abstract provided.

Chemically Induced Conductance Switching In Carbon Nanotube Circuits, Jaan Männik, Brett R. Goldsmith, Alexander Kane, Phillip G. Collins

Jaan Männik

The chemical reactivity of carbon nanotubes in H2SO4 is investigated using individual, single-walled carbon nanotubes (SWNTs) incorporated into electronic devices. Exploiting the device conductance as a sensitive indicator of chemical reactions, discrete oxidation and reduction events can be clearly observed. During oxidation, a SWNT opens circuits to a nanometer-scale tunnel junction with residual conduction similar to Frenkel-Poole charge emission. When electrochemically reduced, a SWNT returns to its original conductance. This redox cycle can be repeated many times, suggesting a novel chemical method of reversibly switching SWNT conductivity.

DOI: 10.1103/PhysRevLett.97.016601

Search For The Theta(+) Pentaquark In The Reaction Gamma D -> Pk(-)K(+)N, B Mckinnon, K Hicks, Na Baltzell, Ds Carman, Md Mestayer, T Mibe, M Mirazita, S Niccolai, P Rossi, S Stepanyan, Dj Tedeschi, P Ambrozewicz, M Anghinolfi, G Asryan, H Avakian, H Bagdasaryan, N Baillie, Jp Ball, V Batourine, M Battaglieri, I Bedlinskiy, M Bellis, N Benmouna, Bl Berman, As Biselli, S Bouchigny, S Boiarinov, R Bradford, D Branford, Wj Briscoe, Wk Brooks, S Bultmann, Vd Burkert, C Butuceanu, Jr Calarco, Sl Careccia, S Chen, Pl Cole, P Collins, P Coltharp, D Crabb, V Crede, D Dale, R De Masi, R Devita, E De Sanctis, Pv Degtyarenko, A Deur, C Djalali, Ge Dodge, J Donnelly, D Doughty, M Dugger, Op Dzyubak, H Egiyan, Ks Egiyan, L Elouadrhiri, P Eugenio, G Fedotov, G Feldman, H Funsten, M Gabrielyan, L Gan, M Garcon, A Gasparian, G Gavalian, Gp Gilfoyle, Kl Giovanetti, Fx Girod, Jt Goetz, A Gonenc, Rw Gothe, Ka Griffioen, M Guidal, N Guler, L Guo, V Gyurjyan, Rs Hakobyan, Fw Hersman, I Hleiqawi, M Holtrop, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, Jd Kellie, M Khandaker, W Kim, A Klein, Fj Klein, M Kossov, Lh Kramer, V Kubarovsky, J Kuhn, Se Kuhn, Sv Kuleshov, J Lachniet, J Langheinrich, D Lawrence, K Livingston, H Lu, M Maccormick, Ba Mecking, Ca Meyer, K Mikhailov, R Miskimen, V Mokeev, Sa Morrow, M Moteabbed, Gs Mutchler, I Nakagawa, P Nadel-Turonski, R Nasseripour, G Niculescu, I Niculescu, Bb Niczyporuk, Mr Niroula, Ra Niyazov, M Nozar, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, C Paterson, J Pierce, N Pivnyuk, O Pogorelko, S Pozdniakov, Jw Price, Y Prok, D Protopopescu, Ba Raue, G Ricco, M Ripani, Bg Ritchie, F Ronchetti, G Rosner, F Sabatie, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, Yg Sharabian, Es Smith, Lc Smith, Di Sober, A Stavinsky, Ss Stepanyan, Be Stokes, P Stoler, Ii Strakovsky, S Strauch, M Taiuti, A Teymurazyan, U Thoma, A Tkabladze, S Tkachenko, C Tur, M Ungaro, Mf Vineyard, Av Vlassov, Lb Weinstein, Dp Weygand, M Williams, E Wolin, Mh Wood, A Yegneswaran, L Zana, J Zhang, B Zhao, Z Zhao

Michael Williams

A search for the Θ+ in the reaction γd→pK-K+n was completed using the CLAS detector at Jefferson Lab. A study of the same reaction, published earlier, reported the observation of a narrow Θ+ resonance. The present experiment, with more than 30 times the integrated luminosity of our earlier measurement, does not show any evidence for a narrow pentaquark resonance. The angle-integrated upper limit on Θ+ production in the mass range of 1.52–1.56  GeV/c2 for the γd→pK-Θ+ reaction is 0.3 nb (95% C.L.). This upper limit depends on assumptions made for the mass and angular distribution of Θ+ production. Using Λ(1520) …

Measurement Of Deeply Virtual Compton Scattering With A Polarized-Proton Target, S Chen, H Avakian, Vd Burkert, P Eugenio, G Adams, M Amarian, P Ambrozewicz, M Anghinolfi, G Asryan, H Bagdasaryan, N Baillie, Jp Ball, Na Baltzell, S Barrow, V Batourine, M Battaglieri, K Beard, I Bedlinskiy, M Bektasoglu, M Bellis, N Benmouna, Bl Berman, As Biselli, Be Bonner, S Bouchigny, S Boiarinov, P Bosted, R Bradford, D Branford, Wj Briscoe, Wk Brooks, S Bultmann, C Butuceanu, Jr Calarco, Sl Careccia, Ds Carman, B Carnahan, A Cazes, Pl Cole, P Collins, P Coltharp, D Cords, P Corvisiero, D Crabb, H Crannell, V Crede, Jp Cummings, R De Masi, R Devita, E De Sanctis, Pv Degtyarenko, H Denizli, L Dennis, A Deur, Kv Dharmawardane, Ks Dhuga, C Djalali, Ge Dodge, J Donnelly, D Doughty, M Dugger, S Dytman, Op Dzyubak, H Egiyan, Ks Egiyan, L El Fassi, L Elouadrhiri, R Fatemi, G Fedotov, G Feldman, Rj Feuerbach, Ta Forest, H Funsten, M Garcon, G Gavalian, Gp Gilfoyle, Kl Giovanetti, Fx Girod, Jt Goetz, E Golovatch, A Gonenc, Rw Gothe, Ka Griffioen, M Guidal, M Guillo, N Guler, L Guo, V Gyurjyan, C Hadjidakis, K Hafidi, H Hakobyan, Rs Hakobyan, J Hardie, D Heddle, Fw Hersman, K Hicks, I Hleiqawi, M Holtrop, M Huertas, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, El Isupov, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, C Keith, Jd Kellie, M Khandaker, Ky Kim, K Kim, W Kim, A Klein, Fj Klein, M Klusman, M Kossov, Lh Kramer, V Kubarovsky, J Kuhn, Se Kuhn, Sv Kuleshov, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, J Li, Acs Lima, K Livingston, H Lu, K Lukashin, M Maccormick, N Markov, S Mcaleer, B Mckinnon, Jwc Mcnabb, Ba Mecking, Md Mestayer, Ca Meyer, T Mibe, K Mikhailov, R Minehart, M Mirazita, R Miskimen, V Mokeev, L Morand, Sa Morrow, M Moteabbed, J Mueller, Gs Mutchler, P Nadel-Turonski, J Napolitano, R Nasseripour, N Natasha, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, Mr Niroula, Ra Niyazov, M Nozar, Gv O'Rielly, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, C Paterson, Sa Philips, J Pierce, 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, Yg Sharabian, J Shaw, Nv Shvedunov, Av Skabelin, Es Smith, Lc Smith, Di Sober, A Stavinsky, Ss Stepanyan, S Stepanyan, Be Stokes, P Stoler, Ii Strakovsky, S Strauch, R Suleiman, M Taiuti, Dj Tedeschi, U Thoma, A Tkabladze, S Tkachenko, L Todor, C Tur, M Ungaro, M Vanderhaeghen, Mf Vineyard, Av Vlassov, Dp Watts, Lb Weinstein, Dp Weygand, M Williams, E Wolin, Mh Wood, A Yegneswaran, J Yun, L Zana, J Zhang, B Zhao, Z Zhao

Michael Williams

The longitudinal target-spin asymmetry AUL for the exclusive electroproduction of high-energy photons was measured for the first time in ep-->e;'pgamma. The data have been accumulated at JLab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH3 target. A significant azimuthal angular dependence was observed, resulting from the interference of the deeply virtual Compton scattering and Bethe-Heitler processes. The amplitude of the sinvarphi moment is 0.252+/-0.042stat+/-0.020sys. Theoretical calculations are in good agreement with the magnitude and the kinematic dependence of the target-spin asymmetry, which is sensitive to the generalized parton distributions H and H.

Η' Photoproduction On The Proton For Photon Energies From 1.527 To 2.227 Gev, M. Dugger, J. P . Ball, P. Collins, E. Pasyuk, B. G. Ritchie, G. Adams, P. Ambrozewicz, E. Anciant, M. Anghinolfi, B. Asavapibhop, G. Asryan, G. Audit, H. Avakian, H. Bagdasaryan, N. Baillie, N. A. Baltzell, S. Barrow, V. Batourine, M. Battaglieri, K. Beard, I. Bedlinsky, M. Bektasoglu, M. Bellis, N. Benmouna, B.L Berman, N. Bianchi, A. S. Biselli, B. E. Bonner, S. Bouchigny, S. Boiarinov, R. Bradford, D. Branford, W. J. Briscoe, W. K. Brooks, S. Bultmann, V. D. Burkert, C. Butcceanu, J. R. Calarco, S. L. Careccia, D. S. Carman, B. Carnahan, S. Chen, P. L . Cole, A. Coleman, P. Coltharp, D. Cords, P. Corvisiero, D. Crabb, H. Crannell, J. P. Cummings, E. De Sanctis, R. Devita, P. V. Degtyarenko, H. Denizli, L. Dennis, A. Deur, K. V. Dharmawardane, K. S. Dhuga, C. Djalali, G. E. Dodge, J. Donnelly, D. Doughty, P. Dragovitsch, S. Dytman, O. P. Dzyubak, H. Egiyan, K. S. Egiyan, L. Elouadhiri, A. Empl, P. Eugenio, R. Fatemi, G. Fedotov, G. Feldman, R J. Feuerbach, T. A. Forest, H. Funsten, M Garcon, G. Gavalian, G. P. Gilfoyle, K. L. Giovanetti, F.X. Girod, J. T. Goetz, R. W. Goethe, K A. Griffioen, M. Cuidal, M. Guillo, N. Guler, L. Guo, V. Gyurjyan, C. Hadjidkas, Michael Williams

Michael Williams

No abstract provided.

Measurement Of Two- And Three-Nucleon Short-Range Correlation Probabilities In Nuclei, Ks Egiyan, Nb Dashyan, Mm Sargsian, Mi Strikman, Lb Weinstein, G Adams, P Ambrozewicz, M Anghinolfi, B Asavapibhop, G Asryan, H Avakian, H Baghdasaryan, N Baillie, Jp Ball, Na Baltzell, V Batourine, M Battaglieri, I Bedlinskiy, M Bektasoglu, M Bellis, N Benmouna, As Biselli, Be Bonner, S Bouchigny, S Boiarinov, R Bradford, D Branford, Wk Brooks, S Bultmann, Vd Burkert, C Bultuceanu, Jr Calarco, Sl Careccia, Ds Carman, B Carnahan, S Chen, Pl Cole, P Coltharp, P Corvisiero, D Crabb, H Crannell, Jp Cummings, Ed Sanctis, R Devita, Pv Degtyarenko, H Denizli, L Dennis, Kv Dharmawardane, C Djalali, Ge Dodge, J Donnelly, D Doughty, P Dragovitsch, M Dugger, S Dytman, Op Dzyubak, H Egiyan, L Elouadrhiri, A Empl, P Eugenio, R Fatemi, G Fedotov, Rj Feuerbach, Ta Forest, H Funsten, G Gavalian, Ng Gevorgyan, Gp Gilfoyle, Kl Giovanetti, Fx Girod, Jt Goetz, E Golovatch, Rw Gothe, Ka Griffioen, M Guidal, M Guillo, N Guler, L Guo, V Gyurjyan, C Hadjidakis, J Hardie, Fw Hersman, K Hicks, I Hleiqawi, M Holtrop, J Hu, M Huertas, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, Jd Kellie, M Khandaker, Ky Kim, K Kim, W Kim, A Klein, Fj Klein, A Klimenko, M Klusman, Lh Kramer, V Kubarovsky, J Kuhn, Se Kuhn, S Kuleshov, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, T Lee, K Livingston, Lc Maximon, S Mcaleer, B Mckinnon, Jwc Mcnabb, Ba Mecking, Md Mestayer, Ca Meyer, T Mibe, K Mikhailov, R Minehart, M Mirazita, R Miskimen, V Mokeev, Sa Morrow, J Mueller, Gs Mutchler, P Nadel-Turonski, J Napolitano, R Nasseripour, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, Ra Niyazov, Gv O'Rielly, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, C Peterson, J Pierce, N 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, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, Yg Sharabian, J Shaw, Es Smith, Lc Smith, Di Sober, A Stavinsky, S Stepanyan, Be Stokes, P Stoler, S Strauch, R Suleiman, M Taiuti, S Taylor, Dj Tedeschi, R Thompson, A Tkabladze, S Tkachenko, L Todor, C Tur, M Ungaro, Mf Vineyard, Av Vlassov, Dp Weygand, M Williams, E Wolin, Mh Wood, A Yegneswaran, J Yun, L Zana, J Zhang

Michael Williams

The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 1 < xB <. At Q2 > 1.4 GeV2, the ratios exhibit two separate plateaus, at 1.5 < xB < 2 and at xB > 2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A = 3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A = 4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.

Electron Scattering From High-Momentum Neutrons In Deuterium, Av Klimenko, Se Kuhn, C Butuceanu, Ks Egiyan, Ka Griffioen, G Adams, P Ambrozewicz, M Anghinolfi, G Asryan, H Avakian, H Bagdasaryan, N Baillie, Jp Ball, Na Baltzell, S Barrow, V Batourine, M Battaglieri, I Bedlinskiy, M Bektasoglu, M Bellis, N Benmouna, As Biselli, S Bouchigny, S Boiarinov, R Bradford, D Branford, Wk Brooks, S Bultmann, Vd Burkert, Jr Calarco, Sl Careccia, Ds Carman, A Cazes, S Chen, Pl Cole, P Coltharp, D Cords, P Corvisiero, D Crabb, Jp Cummings, Nb Dashyan, R Devita, Ed Sanctis, Pv Degtyarenko, H Denizli, L Dennis, Kv Dharmawardane, C Djalali, Ge Dodge, J Donnelly, D Doughty, M Dugger, S Dytman, Op Dzyubak, H Egiyan, L Elouadrhiri, P Eugenio, R Fatemi, G Fedotov, Rg Fersch, Rj Feuerbach, H Funsten, M Garcon, G Gavalian, Gp Gilfoyle, Kl Giovanetti, Fx Girod, Jt Goetz, A Gonenc, Cio Gordon, Rw Gothe, M Guidal, M Guillo, N Guler, L Guo, V Gyurjyan, C Hadjidakis, Rs Hakobyan, J Hardie, Fw Hersman, K Hicks, I Hleiqawi, M Holtrop, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, Jd Kellie, M Khandaker, W Kim, A Klein, Fj Klein, M Kossov, Lh Kramer, V Kubarovsky, J Kuhn, Sv Kuleshov, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, J Li, K Livingston, S Mcaleer, B Mckinnon, Jwc Mcnabb, Ba Mecking, S Mehrabyan, Jj Melone, Md Mestayer, Ca Meyer, T Mibe, K Mikhailov, R Minehart, M Mirazita, R Miskimen, V Mokeev, L Morand, Sa Morrow, J Mueller, Gs Mutchler, P Nadel-Turonski, J Napolitano, R Nasseripour, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, Ra Niyazov, M Nozar, Gv O'Rielly, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, C Paterson, J Pierce, N Pivnyuk, D Pocanic, O Pogorelko, S Pozdniakov, Bm Preedom, Jw Price, Y Prok, D Protopopescu, Ba Raue, G Riccardi, G Ricco, M Ripani, Bg Ritchie, F Ronchetti, G Rosner, P Rossi, F Sabatie, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, Yg Sharabian, Av Skabelin, Es Smith, Lc Smith, Di Sober, A Stavinsky, Ss Stepanyan, S Stepanyan, Be Stokes, P Stoler, S Strauch, M Taiuti, Dj Tedeschi, U Thoma, A Tkabladze, S Tkachenko, L Todor, C Tur, M Ungaro, Mf Vineyard, Av Vlassov, Lb Weinstein, Dp Weygand, M Williams, E Wolin, Mh Wood, A Yegneswaran, L Zana, J Zhang, B Zhao

Michael Williams

We report results from an experiment measuring the semiinclusive reaction 2H(e,e'ps) in which the proton ps is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CEBAF large acceptance spectrometer. A …

Search For Theta(+)(1540) Pentaquark In High-Statistics Measurement Of Gamma P ->(K)Over-Bar(0)K(+)N At Clas, M Battaglieri, R De Vita, V Kubarovsky, L Guo, Gs Mutchler, P Stoler, Dp Weygand, P Ambrozewicz, M Anghinolfi, G Asryan, H Avakian, H Bagdasaryan, N Baillie, Jp Ball, Na Baltzell, V Batourine, I Bedlinskiy, M Bellis, N Benmouna, Bl Berman, As Biselli, S Bouchigny, S Boiarinov, R Bradford, D Branford, Wj Briscoe, Wk Brooks, S Bultmann, Vd Burkert, C Butuceanu, Jr Calarco, Sl Careccia, Ds Carman, S Chen, E Clinton, Pl Cole, P Coltharp, D Crabb, H Crannell, Jp Cummings, D Dale, E De Sanctis, Pv Degtyarenko, A Deur, Kv Dharmawardane, C Djalali, Ge Dodge, J Donnelly, D Doughty, M Dugger, Op Dzyubak, H Egiyan, Ks Egiyan, L Elouadrhiri, P Eugenio, G Fedotov, H Funsten, My Gabrielyan, L Gan, M Garcon, A Gasparian, G Gavalian, Gp Gilfoyle, Kl Giovanetti, Fx Girod, O Glamazdin, J Goett, Jt Goetz, E Golovach, A Gonenc, Cio Gordon, Rw Gothe, Ka Griffioen, M Guidal, N Guler, V Gyurjyan, C Hadjidakis, Rs Hakobyan, J Hardie, Fw Hersman, K Hicks, I Hleiqawi, M Holtrop, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, Jd Kellie, M Khandaker, W Kim, A Klein, Fj Klein, Av Klimenko, M Kossov, Lh Kramer, J Kuhn, Se Kuhn, Sv Kuleshov, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, T Lee, J Li, K Livingston, B Mckinnon, Ba Mecking, Jj Melone, Md Mestayer, Ca Meyer, T Mibe, K Mikhailov, R Minehart, M Mirazita, R Miskimen, V Mochalov, V Mokeev, L Morand, Sa Morrow, P Nadel-Turonski, I Nakagawa, R Nasseripour, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, Ra Niyazov, M Nozar, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, C Paterson, J Pierce, N Pivnyuk, D Pocanic, O Pogorelko, S Pozdniakov, Jw Price, Y Prok, D Protopopescu, Ba Raue, G Riccardi, G Ricco, M Ripani, Bg Ritchie, F Ronchetti, G Rosner, P Rossi, F Sabatie, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, Yg Sharabian, Es Smith, Lc Smith, Di Sober, A Stavinsky, Ss Stepanyan, S Stepanyan, Be Stokes, Ii Strakovsky, S Strauch, M Taiuti, Dj Tedeschi, A Teymurazyan, U Thoma, A Tkabladze, S Tkachenko, L Todor, C Tur, M Ungaro, Mf Vineyard, Av Vlassov, Lb Weinstein, M Williams, E Wolin, Mh Wood, A Yegneswaran, L Zana, J Zhang, B Zhao

Michael Williams

The exclusive reaction gamma p ->(K) over bar (0)K(+)n was studied in the photon energy range between 1.6 and 3.8 GeV searching for evidence of the exotic baryon Theta(+)(1540)-> nK(+). The decay to nK(+) requires the assignment of strangeness S=+1 to any observed resonance. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility corresponding to an integrated luminosity of 70 pb(-1). No evidence for the Theta(+) pentaquark was found. Upper limits were set on the production cross section as function of center-of-mass angle and nK(+) mass. The 95% C.L. upper limit on the total …

Measurement Of The Deuteron Structure Function F-2 In The Resonance Region And Evaluation Of Its Moments, M Osipenko, G Ricco, S Simula, M Battaglieri, M Ripani, G Adams, P Ambrozewicz, M Anghinolfi, B Asavapibhop, G Asryan, G Audit, H Avakian, H Bagdasaryan, N Baillie, Jp Ball, Na Baltzell, S Barrow, V Batourine, K Beard, I Bedlinskiy, M Bektasoglu, M Bellis, N Benmouna, As Biselli, Be Bonner, S Bouchigny, S Boiarinov, R Bradford, D Branford, Wk Brooks, S Bultmann, Vd Burkert, C Butuceanu, Jr Calarco, Sl Careccia, Ds Carman, A Cazes, S Chen, Pl Cole, A Coleman, P Coltharp, D Cords, P Corvisiero, D Crabb, Jp Cummings, E De Sanctis, R Devita, Pv Degtyarenko, H Denizli, L Dennis, A Deur, Kv Dharmawardane, C Djalali, Ge Dodge, J Donnelly, D Doughty, P Dragovitsch, M Dugger, S Dytman, Op Dzyubak, H Egiyan, Ks Egiyan, L Elouadrhiri, A Empl, P Eugenio, R Fatemi, G Fedotov, Rj Feuerbach, Ta Forest, H Funsten, M Garcon, G Gavalian, Gp Gilfoyle, Kl Giovanetti, Fx Girod, Jt Goetz, E Golovatch, Cio Gordon, Rw Gothe, Ka 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, M Huertas, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, Jd Kellie, M Khandaker, Ky Kim, K Kim, W Kim, A Klein, Fj Klein, Av Klimenko, M Klusman, M Kossov, Lh Kramer, V Kubarovsky, J Kuhn, Se Kuhn, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, T Lee, J Li, Acs Lima, K Livingston, K Lukashin, Jj Manak, C Marchand, S Mcaleer, B Mckinnon, Jwc Mcnabb, Ba Mecking, S Mehrabyan, Jj Melone, Md Mestayer, Ca Meyer, K Mikhailov, R Minehart, M Mirazita, R Miskimen, V Mokeev, L Morand, Sa Morrow, J Mueller, Gs Mutchler, P Nadel-Turonski, J Napolitano, R Nasseripour, G Nefedov, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, Ra Niyazov, M Nozar, Gv O'Rielly, Ai Ostrovidov, K Park, E Pasyuk, Sa Philips, J Pierce, N Pivnyuk, D Pocanic, O Pogorelko, E Polli, S Pozdniakov, Bm Preedom, Jw Price, Y Prok, D Protopopescu, Lm Qin, Ba Raue, G Riccardi, Bg Ritchie, F Ronchetti, G Rosner, P Rossi, D Rowntree, Pd Rubin, F Sabatie, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, Yg Sharabian, J Shaw, Av Skabelin, Es Smith, Lc Smith, Di Sober, A Stavinsky, Ss Stepanyan, S Stepanyan, Be Stokes, P Stoler, S Strauch, R Suleiman, M Taiuti, S Taylor, Dj Tedeschi, U Thoma, R Thompson, A Tkabladze, L Todor, C Tur, M Ungaro, Mf Vineyard, Av Vlassov, Lb Weinstein, Dp Weygand, M Williams, E Wolin, Mh Wood, A Yegneswaran, J Yun, L Zana, J Zhang

Michael Williams

Inclusive electron scattering off the deuteron has been measured to extract the deuteron structure function F2 with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. The measurement covers the entire resonance region from the quasi-elastic peak up to the invariant mass of the final-state hadronic system W~2.7 GeV with four-momentum transfers Q2 from 0.4 to 6 (GeV/c)^2. These data are complementary to previous measurements of the proton structure function F2 and cover a similar two-dimensional region of Q2 and Bjorken variable x. Determination of the deuteron F2 over a large x interval including the quasi-elastic …

Measurement Of The N ->Delta (+)(1232) Transition At High-Momentum Transfer By Pi(0) Electroproduction, M Ungaro, P Stoler, I Aznauryan, Vd Burkert, K Joo, Lc Smith, G Adams, M Amarian, P Ambrozewicz, M Anghinolfi, G Asryan, G Audit, H Avakian, H Bagdasaryan, Jp Ball, Na Baltzell, S Barrow, V Batourine, M Battaglieri, I Bedliski, M Bektasoglu, M Bellis, N Benmouna, Bl Berman, As Biselli, Be Bonner, S Bouchigny, S Boiarinov, R Bradford, D Branford, Wj Briscoe, Wk Brooks, S Bultmann, C Butuceanu, Jr Calarco, Sl Careccia, Ds Carman, A Cazes, S Chen, Pl Cole, P Coltharp, D Cords, P Corvisiero, D Crabb, Jp Cummings, E Sanctis, R Devita, Pv Degtyarenko, H Denizli, L Dennis, A Deur, Kv Dharmawardane, C Djalali, Ge Dodge, J Donnelly, D Doughty, M Dugger, S Dytman, Op Dzyubak, H Egiyan, Ks Egiyan, L Elouadrhiri, P Eugenio, R Fatemi, G Fedotov, G Feldman, Rj Feuerbach, H Funsten, M Garcon, G Gavalian, Gp Gilfoyle, Kl Giovanetti, Fx Girod, J Goetz, Cio Gordon, Rw Gothe, Ka Griffioen, M Guidal, M Guillo, N Guler, L Guo, V Gyurjyan, C Hadjidakis, Rs Hakobyan, J Hardie, D Heddle, Fw Hersman, I Hleiqawi, M Holtrop, K Hicks, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, Mm Ito, D Jenkins, Hs Jo, Hg Juengst, Jd Kellie, M Khandaker, W Kim, A Klein, Fj Klein, Av Klimenko, M Kossov, Lh Kramer, V Kubarovsky, J Kuhn, Se Kuhn, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, T Lee, J Li, K Livingston, C Marchand, N Markov, S Mcaleer, B Mckinnon, Jwc Mcnabb, Ba Mecking, S Mehrabyan, Jj Melone, Md Mestayer, Ca Meyer, K Mikhailov, R Minehart, M Mirazita, R Miskimen, V Mokeev, L Morand, Sa Morrow, J Mueller, Gs Mutchler, J Napolitano, R Nasseripour, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, M Niroula, Ra Niyazov, M Nozar, Gv O'Rielly, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, Sa Philips, N 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, Pd Rubin, F Sabatie, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, Yg Sharabian, Av Skabelin, Es Smith, Di Sober, A Stavinsky, Ss Stepanyan, S Stepanyan, Be Stokes, Ii Strakovsky, S Strauch, M Taiuti, Dj Tedeschi, U Thoma, A Tkabladze, L Todor, S Tkachenko, C Tur, Mf Vineyard, Av Vlassov, Lb Weinstein, Dp Weygand, M Williams, E Wolin, Mh Wood, A Yegneswaran, L Zana, B Zhang, J Zhang, B Zhao

Michael Williams

We report a new measurement of the exclusive electroproduction reaction gamma* p -> pi0 p to explore the evolution from soft non-perturbative physics to hard processes via the Q2 dependence of the magnetic (M1+), electric (E1+) and scalar (S1+) multipoles in the N to Delta transition. 9000 differential cross section data points cover W from threshold to 1.4 eV/c2, 4pi center-of-mass solid angle, and Q2 from 3 to 6 GeV2/c2, the highest yet achieved. It is found that the magnetic form factor G*M decreases with Q2 more steeply than the proton magnetic form factor, the ratio E1+/M1+ is small and …

Search For Theta(++) Pentaquarks In The Exclusive Reaction Gamma P -> K(+)K(-)P, V Kubarovsky, M Battaglieri, R De Vita, J Goett, L Guo, Gs Mutchler, P Stoler, Dp Weygand, P Ambrozewicz, M Anghinolfi, G Asryan, H Avakian, H Bagdasaryan, N Baillie, Jp Ball, Na Baltzell, V Batourine, I Bedlinskiy, M Bellis, N Benmouna, Bl Berman, As Biselli, S Bouchigny, S Boiarinov, R Bradford, D Branford, Wj Briscoe, Wk Brooks, S Bueltmann, Vd Burkert, C Butuceanu, Jr Calarco, Sl Careccia, Ds Carman, S Chen, E Clinton, Pl Cole, P Collins, P Coltharp, D Crabb, H Crannell, V Crede, Jp Cummings, R De Masi, D Dale, E De Sanctis, Pv Degtyarenko, A Deur, Kv Dharmawardane, C Djalali, Ge Dodge, J Donnelly, D Doughty, M Dugger, Op Dzyubak, H Egiyan, Ks Egiyan, L Elouadrhiri, P Eugenio, G Fedotov, H Funsten, My Gabrielyan, L Gan, M Garcon, A Gasparian, G Gavalian, Gp Gilfoyle, Kl Giovanetti, Fx Girod, O Glamazdin, Jt Goetz, E Golovach, A Gonenc, Cio Gordon, Rw Gothe, Ka Griffioen, M Guidal, N Guler, V Gyurjyan, C Hadjidakis, K Hafidi, Rs Hakobyan, J Hardie, Fw Hersman, K Hicks, I Hleiqawi, M Holtrop, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, El Isupov, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, Jd Kellie, M Khandaker, W Kim, A Klein, Fj Klein, Av Klimenko, M Kossov, Lh Kramer, J Kuhn, Se Kuhn, Sv Kuleshov, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, T Lee, J Li, K Livingston, H Lu, M Maccormick, N Markov, B Mckinnon, Ba Mecking, Jj Melone, Md Mestayer, Ca Meyer, T Mibe, K Mikhailov, R Minehart, M Mirazita, R Miskimen, V Mochalov, V Mokeev, L Morand, Sa Morrow, M Moteabbed, P Nadel-Turonski, I Nakagawa, R Nasseripour, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, Mr Niroula, Ra Niyazov, M Nozar, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, C Paterson, J Pierce, N Pivnyuk, D Pocanic, O Pogorelko, S Pozdniakov, Jw Price, Y Prok, D Protopopescu, Ba Raue, G Riccardi, G Ricco, M Ripani, Bg Ritchie, F Ronchetti, G Rosner, P Rossi, F Sabatie, C Salgado, Jp Santoro, V Sapunenko, Ra Schumacher, Vs Serov, Yg Sharabian, Nv Shvedunov, Es Smith, Lc Smith, Di Sober, A Stavinsky, Ss Stepanyan, S Stepanyan, Be Stokes, Ii Strakovsky, S Strauch, M Taiuti, Dj Tedeschi, A Teymurazyan, U Thoma, A Tkabladze, S Tkachenko, L Todor, C Tur, M Ungaro, Mf Vineyard, Av Vlassov, Lb Weinstein, M Williams, E Wolin, Mh Wood, A Yegneswaran, L Zana, J Zhang, B Zhao

Michael Williams

The exclusive reaction gamma p ->(K) over bar (0)K(+)n was studied in the photon energy range between 1.6 and 3.8 GeV searching for evidence of the exotic baryon Theta(+)(1540)-> nK(+). The decay to nK(+) requires the assignment of strangeness S=+1 to any observed resonance. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility corresponding to an integrated luminosity of 70 pb(-1). No evidence for the Theta(+) pentaquark was found. Upper limits were set on the production cross section as function of center-of-mass angle and nK(+) mass. The 95% C.L. upper limit on the total …

Differential Cross Sections For Gamma Plus P -> K++ Y For Lambda And Sigma(0) Hyperons, R Bradford, Ra Schumacher, Jwc Mcnabb, L Todor, G Adams, P Ambrozewicz, E Anciant, M Anghinolfi, B Asavapibhop, G Asryan, G Audit, H Avakian, H Bagdasaryan, N Baillie, Jp Ball, Na Baltzell, S Barrow, V Batourine, M Battaglieri, K Beard, I Bedlinskiy, M Bektasoglu, M Bellis, N Benmouna, Bl Berman, N Bianchi, As Biselli, Be Bonner, S Bouchigny, S Boiarinov, D Branford, Wj Briscoe, Wk Brooks, S Bultmann, Vd Burkert, C Butuceanu, Jr Calarco, Sl Careccia, Ds Carman, B Carnahan, S Chen, Pl Cole, A Coleman, P Coltharp, P Corvisiero, D Crabb, H Crannell, Jp Cummings, R Devita, Ed Sanctis, Pv Degtyarenko, H Denizli, L Dennis, A Deur, Kv Dharmawardane, Ks Dhuga, C Djalali, Ge Dodge, J Donnelly, D Doughty, P Dragovitsch, M Dugger, S Dytman, Op Dzyubak, H Egiyan, Ks Egiyan, L Elouadrhiri, A Empl, P Eugenio, R Fatemi, G Fedotov, G Feldman, Rj Feuerbach, Ta Forest, H Funsten, M Garcon, G Gavalian, Gp Gilfoyle, Kl Giovanetti, Fx Girod, Jt Goetz, E Golovatch, A Gonenc, Rw Gothe, Ka 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, M Huertas, Ce Hyde-Wright, Y Ilieva, Dg Ireland, Bs Ishkhanov, Mm Ito, D Jenkins, Hs Jo, K Joo, Hg Juengst, Jd Kellie, M Khandaker, Ky Kim, K Kim, W Kim, A Klein, Fj Klein, Av Klimenko, M Klusman, M Kossov, Lh Kramer, V Kubarovsky, J Kuhn, Se Kuhn, Sv Kuleshov, J Lachniet, Jm Laget, J Langheinrich, D Lawrence, Acs Lima, K Livingston, K Lukashin, Jj Manak, C Marchand, S Mcaleer, B Mckinnon, Ba Mecking, Md Mestayer, Ca Meyer, T Mibe, K Mikhailov, R Minehart, M Mirazita, R Miskimen, V Mokeev, Sa Morrow, V Muccifora, J Mueller, Gs Mutchler, P Nadel-Turonski, J Napolitano, R Nasseripour, S Niccolai, G Niculescu, I Niculescu, Bb Niczyporuk, Ra Niyazov, M Nozar, Gv O'Rielly, M Osipenko, Ai Ostrovidov, K Park, E Pasyuk, C Paterson, Sa Philips, J Pierce, N Pivnyuk, D Pocanic, O Pogorelko, E Polli, I Popa, S Pozdniakov, Bm Preedom, Jw Price, Y Prok, D Protopopescu, Lm Qin, Bp Quinn, 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, Vs Serov, A Shafi, Yg Sharabian, J Shaw, S Simionatto, Av Skabelin, Es Smith, Lc Smith, Di Sober, M Spraker, A Stavinsky, Ss Stepanyan, S Stepanyan, Be Stokes, P Stoler, Ii Strakovsky, S Strauch, R Suleiman, M Taiuti, S Taylor, Dj Tedeschi, U Thoma, R Thompson, A Tkabladze, S Tkachenko, C Tur, M Ungaro, Mf Vineyard, Av Vlassov, K Wang, Lb Weinstein, H Weller, Dp Weygand, M Williams, E Wolin, Mh Wood, A Yegneswaran, J Yun, L Zana, J Zhang, B Zhao

Michael Williams

High-statistics cross sections for the reactions γ+p→K++Λ and γ+p→K++Σ0 have been measured using CLAS at Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85

Interaction-Induced Dipole Moment Of The Ar–H2 Dimer: Dependence On The H2 Bond Length, Robert J. Hinde

Robert Hinde

We present ab initio calculations of the interaction-induced dipole moment of the Ar–H₂ van der Waals dimer. The primary focus of our calculations is on the H₂ bond length dependence of the dipole moment, which determines the intensities of both the collision-induced H₂ = 1 ← 0 fundamental band in gaseous Ar–H₂ mixtures and the dopant-induced H₂ = 1 ← 0 absorption feature in Ar-doped solid H₂ matrices. Our calculations employ large atom-centered basis sets, diffuse bond functions positioned between the two monomers, and a coupled cluster treatment of valence electron correlation; core-valence correlation …

Population Size Bias In Descendant-Weighted Diffusion Quantum Monte Carlo Simulations, G. Lee Warren, Robert Hinde

Robert Hinde

We consider the influence of population size on the accuracy of diffusion quantum Monte Carlo simulations that employ descendant weighting or forward walking techniques to compute expectation values of observables that do not commute with the Hamiltonian. We show that for a simple model system, the d-dimensional isotropic harmonic oscillator, the population size must increase rapidly with d in order to ensure that the simulations produce accurate results. When the population size is too small, expectation values computed using descendant-weighted diffusion quantum Monte Carlo simulations exhibit significant systematic biases.

A Continuous-Time Model Of Topic Co-Occurrence Trends, Wei Li, Xuerui Wang, Andrew Mccallum

Andrew McCallum

Recent work in statistical topic models has investigated richer structures to capture either temporal or inter-topic correlations. This paper introduces a topic model that combines the advantages of two recently proposed models: (1) The Pachinko Allocation model (PAM), which captures arbitrary topic correlations with a directed acyclic graph (DAG), and (2) the Topics over Time model (TOT), which captures time-localized shifts in topic prevalence with a continuous distribution over timestamps. Our model can thus capture not only temporal patterns in individual topics, but also the temporal patterns in their co-occurrences. We present results on a research paper corpus, showing interesting …

Pachinko Allocation: Dag-Structured Mixture Models Of Topic Correlations, Wei Li, Andrew Mccallum

Andrew McCallum

Latent Dirichlet allocation (LDA) and other related topic models are increasingly popular tools for summarization and manifold discovery in discrete data. However, LDA does not capture correlations between topics. In this paper, we introduce the pachinko allocation model (PAM), which captures arbitrary, nested, and possibly sparse correlations between topics using a directed acyclic graph (DAG). The leaves of the DAG represent individual words in the vocabulary, while each interior node represents a correlation among its children, which may be words or other interior nodes (topics). PAM provides a flexible alternative to recent work by Blei and Lafferty (2006), which captures …

Combining Generative And Discriminative Methods For Pixel Classification With Multi-Conditional Learning, B. Michael Kelm, Chris Pal, Andrew Mccallum

Andrew McCallum

It is possible to broadly characterize two approaches to probabilistic modeling in terms of generative and discriminative methods. Provided with sufficient training data the discriminative approach is expected to yield superior accuracy as compared to the analogous generative model since no modeling power is expended on the marginal distribution of the features. Conversely, if the model is accurate the generative approach can perform better with less data. In general it is less vulnerable to overfitting and allows one to more easily specify meaningful priors on the model parameters. We investigate multi-conditional learning--a method combining the merits of both approaches. Through …

Tractable Learning And Inference With High-Order Representations, Aron Culotta, Andrew Mccallum

Andrew McCallum

Representing high-order interactions in data often results in large models with an intractable number of hidden variables. In these models, inference and learning must operate without instantiating the entire set of variables. This paper presents a Metropolis-Hastings sampling approach to address this issue, and proposes new methods to discriminatively estimate the proposal and target distribution of the sampler using a ranking function over configurations. We demonstrate our approach on the task of paper and author deduplication, showing that our method enables complex, advantageous representations of the data while maintaining tractable learning and inference procedures.

Group And Topic Discovery From Relations And Their Attributes, Xuerui Wang, Natasha Mohanty, Andrew Mccallum

Andrew McCallum

We present a probabilistic generative model of entity relationships and their attributes that simultaneously discovers groups among the entities and topics among the corresponding textual attributes. Block-models of relationship data have been studied in social network analysis for some time. Here we simultaneously cluster in several modalities at once, incorporating the attributes (here, words) associated with certain relationships. Significantly, joint inference allows the discovery of topics to be guided by the emerging groups, and vice-versa. We present experimental results on two large data sets: sixteen years of bills put before the U.S. Senate, comprising their corresponding text and voting records, …

Learning Field Compatibilities To Extract Database Records From Unstructured Text, Michael Wick, Aron Culotta, Andrew Mccallum

Andrew McCallum

Named-entity recognition systems extract entities in text by type, such as people, organizations, and locations from unstructured text. Rather than extract these fields in isolation, in this paper we present a record extraction system that clusters fields together into records (i.e. database tuples). We construct a probabilistic model of the compatibility of field values, then employ graph partitioning algorithms to partition fields into cohesive records. We also investigate compatibility functions over sets of fields, rather than simply pairs of fields, to examine how higher representational power can impact performance. We apply our techniques to the task of extracting contact records …

Cc Prediction With Graphical Models, Chris Pal, Andrew Mccallum

Andrew McCallum

We address the problem of suggesting who to add as an additional recipient (i.e. cc, or carbon copy) for an email under composition. We address the problem using graphical models for words in the body and subject line of the email as well as the recipients given so far on the email. The problem of cc prediction is closely related to the problem of expert finding in an organization. We show that graphical models present a variety of solutions to these problems. We present results using naively structured models and introduce a powerful new modeling tool: plated factor graphs.

Multi-Conditional Learning For Joint Probability Models With Latent Variables, Chris Pal, Xuerui Wang, Michael Kelm, Andrew Mccallum

Andrew McCallum

We introduce Multi-Conditional Learning, a framework for optimizing graphical models based not on joint likelihood, or on conditional likelihood, but based on a product of several marginal conditional likelihoods each relying on common sets of parameters from an underlying joint model and predicting different subsets of variables conditioned on other subsets. When applied to undirected models with latent variables, such as the Harmonium, this approach can result in powerful, structured latent variable representations that combine some of the advantages of conditional random fields with the unsupervised clustering ability of popular topic models, such as latent Dirichlet allocation and its successors. …

On Discriminative And Semi-Supervised Dimensionality Reduction, Chris Pal, Michael Kelm, Xuerui Wang, Greg Druck, Andrew Mccallum

Andrew McCallum

We are interested in using the goal of making predictions to influence dimensionality reduction procedures. A number of new methods are emerging aimed at combining attributes of generative and discriminative approaches to data modeling. New approaches to semi-supervised learning have also been emerging. We present and apply some new methods to non-linear and richly structured problems comparing and contrasting models designed for computer vision with those designed for text processing and discuss essential properties that need to be preserved when reducing dimensionality.

Integrating Probabilistic Extraction Models And Data Mining To Discover Relations And Patterns In Text, Aron Culotta, Andrew Mccallum, Jonathon Betz

Andrew McCallum

In order for relation extraction systems to obtain human-level performance, they must be able to incorporate relational patterns inherent in the data (for example, that one's sister is likely one's mother's daughter, or that children are likely to attend the same college as their parents). Hand-coding such knowledge can be time-consuming and inadequate. Additionally, there may exist many interesting, unknown relational patterns that both improve extraction performance and provide insight into text. We describe a probabilistic extraction model that provides mutual benefits to both ``top-down'' relational pattern discovery and ``bottom-up'' relation extraction.

Joint Group And Topic Discovery From Relations And Text, Andrew Mccallum, Xuerui Wang, Natasha Mohanty

Andrew McCallum

We present a probabilistic generative model of entity relationships and textual attributes; the model simultaneously discovers groups among the entities and topics among the corresponding text. Block models of relationship data have been studied in social network analysis for some time, however here we cluster in multiple modalities at once. Significantly, joint inference allows the discovery of groups to be guided by the emerging topics, and vice-versa. We present experimental results on two large data sets: sixteen years of bills put before the U.S. Senate, comprising their corresponding text and voting records, and 43 years of similar data from the …

Multi-Conditional Learning: Generative/Discriminative Training For Clustering And Classification, Andrew Mccallum, Chris Pal, Greg Druck, Xuerui Wang

Andrew McCallum

This paper presents multi-conditional learning MCL), a training criterion based on a product of multiple conditional likelihoods. When combining the traditional conditional probability of "label given input" with a generative probability of "input given label" the later acts as a surprisingly effective regularizer. When applied to models with latent variables, MCL combines the structure-discovery capabilities of generative topic models, such as latent Dirichlet allocation and the exponential family harmonium, with the accuracy and robustness of discriminative classifiers, such as logistic regression and conditional random fields. We present results on several standard text data sets showing significant reductions in classification error …