Non-Classical Response from Quench-Cooled Solid Helium Confined in Porous Gold (2009)
Kim, D. Y., Kwon, S., Choi, H., Kim, H. C., Kim, E.
We have investigated the non-classical response of solid 4He confined in porous gold set to torsional oscillation. When solid helium is grown rapidly, nearly 7% of the solid helium appears to be...
Broadband electromagnetic response and ultrafast dynamics of few-layer epitaxial graphene (2009)
Choi, H., Borondics, F., Siegel, D. A., Zhou, S. Y., Martin, M. C., Lanzara, A., ...
We report the first study of the broadband optical conductivity and ultrafast carrier dynamics of epitaxial graphene in the few-layer limit. Equilibrium spectra of nominally buffer, monolayer, and...
Ko, S, Hong, M, Park, B, Gupta, R, Choi, H, Bhattacharya, S
Biodegradable poly (lactic acid) (PLA)/poly (butyleneadipate-co- butyleneterephthalate) (PBAT)/multi-walled carbon nanotube (MWNT) polymer blend nanocomposites were prepared by using a...
Anomalous Attenuation of Transverse Sound in 3He (2008)
Davis, J. P., Pollanen, J., Choi, H., Sauls, J. A., Halperin, W. P., Vorontsov, A. B.
We present the first measurements of the attenuation of transverse sound in superfluid 3He-B. We use fixed path length interferometry combined with the magneto-acoustic Faraday effect to vary the...
Impurity Effects of Aerogel in Superfluid $^{3}$He (2008)
Halperin, W. P., Choi, H., Davis, J. P., Pollanen, J.
The discovery of superfluid $^{3}$He in high porosity silica aerogels, and subsequent experimental and theoretical work, have led to a better general understanding of quasiparticle scattering from...
Superfluid Phase Stability of $^3$He in Axially Anisotropic Aerogel (2008)
Pollanen, J., Davis, J. P., Reddy, B., Shirer, K. R., Choi, H., Halperin, W. P.
Measurements of superfluid $^3$He in 98% aerogel demonstrate the existence of a metastable \emph{A}-like phase and a stable \emph{B}-like phase. It has been suggested that the relative stability of...
Low temperature thermal resistance for a new design of silver sinter heat exchanger (2008)
Pollanen, J., Choi, H., Davis, J. P., Rolfs, B. T., Halperin, W. P.
We have developed a novel procedure for constructing high surface area silver sinter heat exchangers. Our recipe incorporates nylon fibers having a diameter of ~ 50 microns and thin wires of bulk...
High frequency sound in superfluid 3He-B (2008)
Davis, J. P., Choi, H., Pollanen, J., Halperin, W. P.
We present measurements of the absolute phase velocity of transverse and longitudinal sound in superfluid 3He-B at low temperature, extending from the imaginary squashing mode to near pair-breaking....
Tsutomu, A, Parton, B, Saksiri, B, Trager, B, Briggs, C, Camp, C, ...
Davis, J. P., Pollanen, J., Reddy, B., Shirer, K. R., Choi, H., Halperin, W. P.
It has been suggested that anisotropic quasiparticle scattering will stabilize anisotropic phases of superfluid $^3$He contained within highly porous silica aerogel. For example, global anisotropy...
SIMULATION OF KNOCK WITH DIFFERENT PISTON SHAPES IN A HEAVY-DUTY LPG ENGINE (2008)
CHOI, H., LIM, J., MIN, K., LEE, D.
In this study, a three-dimensional transient simulation with a knock model was performed to predict knock occurrence and autoignition site in a heavy-duty LPG engine. A FAE (Flame Area Evolutoin)...
Discovery of an Excited Pair State in Superfluid 3He (2008)
Davis, J. P., Pollanen, J., Choi, H., Sauls, J. A., Halperin, W. P.
Order parameter collective modes are the fingerprint of a condensed phase. The spectroscopy of these modes in superfluid $^3$He and unconventional superconductors can provide key information on the...
Globally Anisotropic High Porosity Silica Aerogels (2007)
Pollanen, J., Shirer, K., Blinstein, S., Davis, J. P., Choi, H., Lippman, T. M., ...
We discuss two methods by which high porosity silica aerogels can be engineered to exhibit global anisotropy. First, anisotropy can be introduced with axial strain. In addition, intrinsic anisotropy...
Dept.ofMechanicalEngrg.,CollegeofEngrg.,SeoulNationalUniversity Seoul 151-742, Korea (2007)
J. Y. Yoo, H. Choi, S. K. Cho, S. K. Cho
The authors wish to express their deepest gratitude for the financial
Strong Coupling Corrections to the Ginzburg-Landau Theory of Superfluid ^{3}He (2007)
Choi, H., Davis, J. P., Pollanen, J., Haard, T. M., Halperin, W. P.
In the Ginzburg-Landau theory of superfluid $^{3}$He, the free energy is expressed as an expansion of invariants of a complex order parameter. Strong coupling effects, which increase with increasing...
Lee, H, Park, B, Choi, H, Gupta, R, Bhattacharya, S
Ethylene-vinyl acetate copolymer ( EVA) with 40 wt.% vinyl acetate content ( EVA40)/organoclay nanocomposites were prepared using a melt intercalation method with several different clay...
Collective Modes and f-wave Pairing Interactions in Superfluid 3He (2006)
Davis, J. P., Choi, H., Pollanen, J., Halperin, W. P.
Precision measurements of a collective mode in superfluid 3He B are sensitive to quasiparticle and f wave pairing interactions. Measurements were performed at various pressures using interference of...
Anisotropic Aerogels for Studying Superfluid $^3$He (2006)
Pollanen, J., Blinstein, S., Choi, H., Davis, J. P., Lippman, T. M., Lurio, L. B., ...
It may be possible to stabilize new superfluid phases of $^{3}$He with anisotropic silica aerogels. We discuss two methods that introduce anisotropy in the aerogel on length scales relevant to...
Magnetoresistance of UPt3 (2006)
Lippman, T. M., Davis, J. P., Choi, H., Pollanen, J., Halperin, W. P.
We have performed measurements of the temperature dependence of the magnetoresistance up to 9 T in bulk single crystals of UPt3 with the magnetic field along the b axis, the easy magnetization axis....
Imaginary Squashing Mode Spectroscopy of Helium Three B (2006)
Davis, J. P., Choi, H., Pollanen, J., Halperin, W. P.
We have made precision measurements of the frequency of a collective mode of the superfluid 3He-B order parameter, the J=2- imaginary squashing mode. Measurements were performed at multiple pressures...
Specific Heat of Disordered $^{3}$He (2006)
Choi, H., Davis, J. P., Pollanen, J., Mulders, N., Halperin, W. P.
Porous aerogel is a source of elastic scattering in superfluid 3He and modifies the properties of the superfluid, suppressing the transition temperature and order parameter. The specific heat jumps...
Analysis of Strong-Coupling Parameters for Superfluid 3He (2006)
Choi, H., Davis, J. P., Pollanen, J., Haard, T. M., Halperin, W. P.
Superfluid $^{3}$He experiments show strong deviation from the weak-coupling limit of the Ginzburg-Landau theory, and this discrepancy grows with increasing pressure. Strong-coupling contributions to...
Acoustic Spectroscopy of Superfluid 3He in Aerogel (2006)
Davis, J. P., Choi, H., Pollanen, J., Halperin, W. P.
We have designed an experiment to study the role of global anisotropic quasiparticle scattering on the dirty aerogel superfluid 3He system. We observe significant regions of two stable phases at...
Compressed Silica Aerogels for the Study of Superfluid 3He (2006)
Pollanen, J., Choi, H., Davis, J. P., Blinstein, S., Lippman, T. M., Lurio, L. B., ...
We have performed Small Angle X-ray Scattering (SAXS) on uniaxially strained aerogels and measured the strain-induced structural anisotropy. We use a model to connect our SAXS results to anisotropy...
Surface Specific Heat of $^{3}$He and Andreev Bound States (2006)
Choi, H., Davis, J. P., Pollanen, J., Halperin, W. P.
High resolution measurements of the specific heat of liquid $^{3}$He in the presence of a silver surface have been performed at temperatures near the superfluid transition in the pressure range of 1...
A Preliminary Examination of the Evocative Effects of the Establishing Operation (2006)
O'Reilly, M, Sigafoos, J, Edrisinha, C, Lancioni, G, Cannella, H, Choi, H, ...
Rapid and sensitive fluorescent peptide quantification using epicocconone (2006)
Karuso, P. H, Crawford, A. S, Chen, D. E, Meheigh, R. J, Geppo, B. S, Scott, G. B, ...
Peptide quantification is a pre-requisite in many areas of proteomics and peptidomics. For example, methods to separate peptides based on chromatography or electrophoresis, require accurate loading...
Real-time monitoring of tryptic digests using the fluorophore epicocconone (2006)
Choi, H, Crawford, A. S, Chen, D. E, Meheigh, R. J, Wildsmith, J, Ray, K. M, ...
Mass Spectrometry is a powerful tool for protein identification following proteolytic digestion using a protease such as trypsin. One problem inherent to the use of proteases is ensuring that...
PHYSICAL PHANTOM OF TYPICAL KOREAN MALE FOR RADIATION PROTECTION PURPOSE (2006)
Kim, J. I., Choi, H., Lee, B. I., Lim, Y. K., Kim, C. S., Lee, J. K., ...
Dose distribution within a human body can be measured using physical anthropomorphic phantoms. In an effort to establish reference Korean physical model, the first Korean physical phantom of average...
PHYSICAL PHANTOM OF TYPICAL KOREAN MALE FOR RADIATION PROTECTION PURPOSE (2006)
Kim, J. I., Choi, H., Lee, B. I., Lim, Y. K., Kim, C. S., Lee, J. K., ...
Dose distribution within a human body can be measured using physical anthropomorphic phantoms. In an effort to establish reference Korean physical model, the first Korean physical phantom of average...
Physical phantom of typical Korean male for radiation protection purpose (2006)
Kim, J. I., Choi, H., Lee, B. I., Lim, Y. K., Kim, C. S., Lee, J. K., ...
Dose distribution within a human body can be measured using physical anthropomorphic phantoms. In an effort to establish reference Korean physical model, the first Korean physical phantom of average...
Bonvalot, S, Casali, P, Choi, H, Debiec-Richter, M, Dei Tos, A P, ...
BACKGROUND: The management of gastrointestinal stromal tumors (GIST) has evolved very rapidly in the last 4 years. The objectives of this international consensus meeting were to describe the optimal...
Bonvalot, S, Casali, P, Choi, H, Debiec-Richter, M, Dei Tos, AP, ...
BACKGROUND: The management of gastrointestinal stromal tumors (GIST) has evolved very rapidly in the last 4 years. The objectives of this international consensus meeting were to describe the optimal...
Wright, I.C., Graham, I.J., Chang, S.W., Choi, H., Lee, S.R.
An extensive ferromanganese nodule field adjacent to the Campbell Plateau in the Southwest Pacific Ocean forms beneath the Deep Western Boundary Current (DWBC) and Antarctic Circumpolar Current...
Bonvalot, S., Casali, P., Choi, H., Debiec-Richter, M., Dei Tos, A. P., ...
Background: The management of gastrointestinal stromal tumors (GIST) has evolved very rapidly in the last 4 years. The objectives of this international consensus meeting were to describe the optimal...
Specific Heat of Disordered Superfluid $^{3}$He (2004)
Choi, H., Yawata, K., Haard, T. M., Davis, J. P., Gervais, G., Mulders, N., ...
The specific heat of superfluid $^{3}$He, disordered by a silica aerogel, is found to have a sharp discontinuity marking the thermodynamic transition to superfluidity at a temperature reduced from...
Thesis (Ph. D.).
Two photon spectroscopy of samarium(III) in the elpasolite CS2NaYC16:Sm3+ (1999)
Thorne, JRG, Karunathilake, A, Choi, H, Denning, RG, Luxbacher, T
Distributed Optimisation: A case study of utilising teaching space in a college (1996)
B. Richards, S. Das, H. Choi, A. El-kholy, V. Liatsos, C. Harrison
This paper presents an approach to distributed optimisation applied to the problem of teaching space utilisation in a college. We describe the basic ingredients of the problem and analyse various...
Negative pion photoproduction from^{15}N in the region of the Delta resonance (1995)
Bergstrom, J.C., Choi, H., Chung, H.T., Gresko, T., Hallin, E.L., Hesselink, W.H.A., ...
SAKAMOTO, M., YASUMOTO, M., OHSUMI, H., CHOI, H., SHIBATA, Y., KANO, T.
We have studied the effects of midazolam and flumazenil on the carotid sinus baroreflex, by examining mean arterial pressure (MAP) and heart rate (HR) responses to partial or complete bilateral...
Construction of Minimal n-2-n Encoders for Any n (1993)
D. S. Phatak, H. Choi, I. Koren
The encoding problem [1] is an important canonical problem. It has widely been used as a benchmark. Here, we have analytically derived minimal--sized nets necessary and sufficient to solve encoding...
INTERACTION OF POLARISED 7 Li WITH 54Fe AT 70 MeV (1990)
Karban, O., Kuburas, G., Blyth, C., Choi, H., Davis, N., Hall, S., ...
The 7Li + 54Fe system was chosen to test the tidal symmetry model in the Fraunhofer scattering region and to investigate the sensitivity of analysing powers in the reaction channel to the...
INTERACTION OF POLARISED 7 Li WITH 54Fe AT 70 MeV (1990)
Karban, O., Kuburas, G., Blyth, C., Choi, H., Davis, N., Hall, S., ...
The 7Li + 54Fe system was chosen to test the tidal symmetry model in the Fraunhofer scattering region and to investigate the sensitivity of analysing powers in the reaction channel to the...
INTERACTION OF POLARISED 7 Li WITH 54Fe AT 70 MeV (1990)
Karban, O., Kuburas, G., Blyth, C., Choi, H., Davis, N., Hall, S., ...
The 7Li + 54Fe system was chosen to test the tidal symmetry model in the Fraunhofer scattering region and to investigate the sensitivity of analysing powers in the reaction channel to the...
Renal Failure Due to Leukaemic Infiltration in Chronic Lymphocytic Leukaemia (1990)
Saggi, S., Calandri, C., Muhlfelder, T., Choi, H., Kahn, T., Kaji, D.
Choi, H, American Mathematical Society
Incluye bibliografía
Controlling for time-dependent confounding using marginal structural models
Zoe Fewell, M. A. Hernan, F. Wolfe, K. Tilling, H. Choi
Longitudinal studies in which exposures, confounders and outcomes are measured repeatedly over time have the potential to allow causal inferences about the effects of exposure on outcome. There is...
Local likelihood density estimation on random fields
Lee, Y. K., Choi, H., Park, B. U., Yu, K. S.
Local likelihood methods hold considerable promise in density estimation. They offer unmatched flexibility and adaptivity as the resulting density estimators inherit both of the best properties of...