Browsing FAS Scholarly Articles by Title

Now showing items 2663-2682 of 18292

    • Compressible Quantum Phases from Conformal Field Theories in 2+1 Dimensions 

      Sachdev, Subir (American Physical Society, 2012)
      Conformal field theories (CFTs) with a globally conserved U(1) charge Q can be deformed into compressible phases by modifying their Hamiltonian, H, by a chemical potential H→H-μQ. We study 2+1 dimensional CFTs upon which ...

    • Compression in visual working memory: Using statistical regularities to form more efficient memory representations. 

      Brady, Timothy F.; Konkle, Talia; Alvarez, George (American Psychological Association (APA), 2009)
      The information that individuals can hold in working memory is quite limited, but researchers have typically studied this capacity using simple objects or letter strings with no associations between them. However, in the ...

    • Compressive Sensing Based Channel Feedback Protocols for Spatially-Correlated Massive Antenna Arrays 

      Kuo, Ping-Heng; Kung, H. T.; Ting, Pang-an (Institute of Electrical and Electronics Engineers, 2012)
      Incorporating wireless transceivers with numerous antennas (such as Massive-MIMO) is a prospective way to increase the link capacity or enhance the energy efficiency of future communication systems. However, the benefits ...

    • Compressive Sensing Medium Access Control for Wireless LANs 

      Lin, Tsung-Han; Kung, H. T. (Institute of Electrical and Electronics Engineers, 2012)
      We propose a medium access control (MAC) protocol for wireless local area networks (LANs) that leverages the theory of compressive sensing. The proposed compressive sensing MAC (CS-MAC) exploits the sparse property that, ...

    • Compressive Sensing with Directly Recoverable Optimal Basis and Applications in Spectrum Sensing 

      Gwon, Youngjune Lee; Kung, H. T.; Vlah, Dario (2011)
      We describe a method of integrating Karhunen-Loeve Transform (KLT) into compressive sensing, which can as a result leverage KLT’s optimality in revealing the sparsity of a signal. We present two complementary results: (1) ...

    • Compressive Sensing with Optimal Sparsifying Basis and Applications in Spectrum Sensing 

      Gwon, Youngjune Lee; Kung, H. T.; Vlah, Dario (Institute of Electrical and Electronics Engineers, 2012)
      We describe a method of integrating Karhunen-Loève Transform (KLT) into compressive sensing, which can as a result improve the compression ratio without affecting the accuracy of decoding. We present two complementary ...

    • Compton scattering from Li6 at 86 MeV 

      Myers, L. S.; Ahmed, M. W.; Feldman, Gary J.; Kafkarkou, A.; Kendellen, D. P.; Mazumdar, I.; Mueller, J. M.; Sikora, M. H.; Weller, H. R.; Zimmerman, W. R. (American Physical Society (APS), 2014)
      Cross sections for 6Li(γ,γ) 6Li have been measured at the High Intensity Gamma-Ray Source (HI~γS) and the sensitivity of these cross sections to the nucleon isoscalar polarizabilities was studied. Data were collected using ...

    • Compton scattering from the deuteron below pion-production threshold 

      Myers, L. S.; Annand, J. R. M.; Brudvik, J.; Feldman, Gary J.; Fissum, K. G.; Grießhammer, H. W.; Hansen, K.; Henshaw, S. S.; Isaksson, L.; Jebali, R.; Kovash, M. A.; Lundin, M.; Middleton, D. G.; Nathan, A. M.; Schröder, B.; Stave, S. C. (American Physical Society (APS), 2015)
      Differential cross sections for elastic scattering of photons from the deuteron have recently been measured at the Tagged-Photon Facility at the MAX IV Laboratory in Lund, Sweden. These first new measurements in more than ...

    • Compulsory Premarital Screening for the Human Immunodeficiency Virus: Technical and Public Health Considerations 

      Cleary, Paul D.; Barry, Michael John; Mayer, Kenneth Hugh; Brandt, Allan M.; Gostin, Larry; Fineberg, Harvey V. (American Medical Association, 1987)
      The effectiveness of a mandatory premarital screening program was examined as a means of curtailing the spread of the human immunodeficiency virus (HIV) infection in the United States. The epidemiology of the HIV, the ...

    • Computation and Visualization of Casimir Forces in Arbitrary Geometries: Nonmonotonic Lateral-Wall Forces and the Failure of Proximity-Force Approximations 

      Rodriguez, Alejandro; Ibanescu, Mihai; Iannuzzi, Davide; Capasso, Federico; Joannopoulos, J. D.; Johnson, Steven G. (American Physical Society, 2007)
      We present a method of computing Casimir forces for arbitrary geometries, with any desired accuracy, that can directly exploit the efficiency of standard numerical-electromagnetism techniques. Using the simplest possible ...

    • Computation of p-Adic Heights and Log Convergence 

      Mazur, Barry C.; Stein, William; Tate, John Torrence (Universität Bielefeld, Fakultät für Mathematik, 2006)
      This paper is about computational and theoretical questions regarding p-adic height pairings on elliptic curves over a global field K. The main stumbling block to computing them efficiently is in calculating, for each of ...

    • Computation of Semantic Number from Morphological Information 

      Berent, Iris; Pinker, Steven; Tzelgov, Joseph; Bibi, Uri; Goldfarb, Liat (2005)
      The distinction between singular and plural enters into linguistic phenomena such as morphology, lexical semantics, and agreement and also must interface with perceptual and conceptual systems that assess numerosity in the ...

    • Computational Caches 

      Waterland, Amos; Angelino, Elaine Lee; Cubuk, Ekin Dogus; Kaxiras, Efthimios; Adams, Ryan Prescott; Appavoo, Jonathan; Seltzer, Margo I. (ACM Press, 2013)
      Caching is a well-known technique for speeding up computation. We cache data from file systems and databases; we cache dynamically generated code blocks; we cache page translations in TLBs. We propose to cache the act of ...

    • Computational Challenges in E-Commerce 

      Feigenbaum, Joan; Parkes, David C.; Pennock, David M. (Association for Computing Machinery, 2009)
      Economic and social sciences will drive Internet protocols and services into the future.

    • Computational Color Constancy with Spatial Correlations 

      Chakrabarti, Ayan; Hirakawa, Keigo; Zickler, Todd (2010)
      The color of a scene recorded by a trichromatic sensor varies with the spectral distribution of the illuminant. For recognition and many other applications, we seek to process these measurements to obtain a color representation ...

    • Computational Complexity 

      Vadhan, Salil P. (Springer, 2011)

    • Computational complexity in electronic structure 

      Whitfield, James; Love, Peter; Aspuru-Guzik, Alan (Royal Society of Chemistry, 2013)
      In quantum chemistry, the price paid by all known efficient model chemistries is either the truncation of the Hilbert space or uncontrolled approximations. Theoretical computer science suggests that these restrictions are ...

    • The Computational Complexity of Cartographic Label Placement 

      Marks, Joe; Shieber, Stuart Merrill (1991)
      We examine the computational complexity of cartographic label placement, a problem derived from the cartographer's task of placing text labels adjacent to map features in such a way as to minimize overlaps with other labels ...

    • Computational complexity of ecological and evolutionary spatial dynamics 

      Ibsen-Jensen, Rasmus; Chatterjee, Krishnendu; Nowak, Martin (National Academy of Sciences, 2015)
      There are deep, yet largely unexplored, connections between computer science and biology. Both disciplines examine how information proliferates in time and space. Central results in computer science describe the complexity ...

    • The Computational Complexity of Nash Equilibria in Concisely Represented Games 

      Schoenebeck, Grant R.; Vadhan, Salil P. (Association for Computing Machinery (ACM), 2012)
      Games may be represented in many different ways, and different representations of games affect the complexity of problems associated with games, such as finding a Nash equilibrium. The traditional method of representing a ...