Showing papers by "Korea University published in 2003"
TL;DR: In this article, a narrow charmonium-like state produced in the exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi has been observed, which has a mass of 3872.0+/-0.6(stat)+/- 0.5(syst) MeV.
Abstract: We report the observation of a narrow charmoniumlike state produced in the exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi. This state, which decays into pi(+)pi(-)J/psi, has a mass of 3872.0+/-0.6(stat)+/-0.5(syst) MeV, a value that is very near the M(D0)+M(D(*0)) mass threshold. The results are based on an analysis of 152M B-Bmacr; events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider. The signal has a statistical significance that is in excess of 10sigma.
1,294 citations
TL;DR: Lee et al. as discussed by the authors examined how ownership structure and conflicts of interest among shareholders under a poor corporate governance system affected firm performance before the crisis and found that firms with low ownership concentration show low firm profitability, controlling for firm and industry characteristics.
938 citations
TL;DR: In this article, a multinomial logistic regression model is proposed to evaluate contagion in financial markets, which captures the coincidence of extreme return shocks across countries within a region and across regions.
Abstract: This article proposes a new approach to evaluate contagion in financial markets. Our measure of contagion captures the coincidence of extreme return shocks across countries within a region and across regions. We characterize the extent of contagion, its economic significance, and its determinants using a multinomial logistic regression model. Applying our approach to daily returns of emerging markets during the 1990s, we find that contagion is predictable and depends on regional interest rates, exchange rate changes, and conditional stock return volatility. Evidence that contagion is stronger for extreme negative returns than for extreme positive returns is mixed.
879 citations
Seoul National University1, Kobe University2, University of Washington3, University of California, Irvine4, Chonnam National University5, University of Tokyo6, Kyoto University7, Tohoku University8, Stony Brook University9, Okayama University10, Boston University11, University of Warsaw12, Korea University13, Niigata University14, Dongshin University15, Massachusetts Institute of Technology16, Tokyo University of Science17
TL;DR: The K2K experiment observed indications of neutrino oscillation after 250 km flight of υμ. as mentioned in this paper The observed number of events in the data corresponding to 4.8 x 1019 protons on target is 56, while 80.1 5.4 + 6.2 is expected.
Abstract: The K2K experiment observed indications of neutrino oscillation after 250 km flight of υμ. The observed number of events in the data corresponding to 4.8 x 1019 protons on target is 56, while 80.1 5.4 +6.2 is expected. Both the decrease of the events and observed spectrum shape distortion are consistent with neutrino oscillation. The probability that the observations are statistical fluctuation of non oscillation is less than 1%. The allowed region of oscillation parameters is consistent with the one obtained from the atmospheric neutrino observation. After the accident of Super-Kamiokande (SK) detector, the reconstruction of SK has finished in 2002 and the K2K experiment resumed in December 2002.
702 citations
TL;DR: In this article, the water insolubility of carboxymethyl chitosans at various pHs varied with the degree of the carboxyethylation and the reaction temperature, and the ratio of water/isopropanol in the reaction solvent.
687 citations
TL;DR: It is recognized that higher digestion efficiencies of the WAS were obtained through thermochemical pretreatment of the sludge, which gave the best results.
671 citations
TL;DR: In this article, the anisotropy parameter of the second harmonic of the azimuthal particle distribution has been measured with the PHENIX detector in Au+Au collisions at roots(NN)=200 GeV for identified and inclusive charged particle production at central rapidities.
Abstract: The anisotropy parameter (v(2)), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in Au+Au collisions at roots(NN)=200 GeV for identified and inclusive charged particle production at central rapidities (eta 2 GeV/c, in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated.
570 citations
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TL;DR: In this article, empirical evidence on how education is related to income distribution in a panel data set covering a broad range of countries for the period between 1960 and 1990 was presented, showing that higher educational attainment and more equal distribution of education play a significant role in making income distribution more equal.
Abstract: This paper presents empirical evidence on how education is related to income distribution in a panel data set covering a broad range of countries for the period between 1960 and 1990. The findings indicate that educational factors - higher educational attainment and more equal distribution of education - play a significant role in making income distribution more equal. The results also confirm the Kuznets inverted-U curve for the relationship between income level and income inequality. We also find that government social expenditure contributes to more equal distribution of income. However, a significant proportion of cross-country variation in income inequality remains unexplained.
534 citations
TL;DR: In this article, a sample of group-affiliated public firms in Korea was used to examine simultaneous causality between ownership structure and performance, and the results show that performance determine ownership structure.
Abstract: In this study, a sample of group-affiliated public firms in Korea was used to examine simultaneous causality between ownership structure and performance. The results show that performance determine...
497 citations
TL;DR: In this paper, the authors measured the transverse momentum spectra of neutral pions in the range 1 < p_T < 10 GeV/c and showed that the pi^0 multiplicity in central reactions is significantly below the yields measured at the same squarert(s_NN) in peripheral Au+Au and p+p reactions scaled by the number of nucleon-nucleon collisions.
Abstract: Transverse momentum spectra of neutral pions in the range 1 < p_T < 10 GeV/c have been measured at mid-rapidity by the PHENIX experiment at RHIC in Au+Au collisions at sqrt(s_NN) = 200 GeV. The pi^0 multiplicity in central reactions is significantly below the yields measured at the same sqrt(s_NN) in peripheral Au+Au and p+p reactions scaled by the number of nucleon-nucleon collisions. For the most central bin, the suppression factor is ~2.5 at p_T = 2 GeV/c and increases to ~4-5 at p_T ~= 4 GeV/c. At larger p_T, the suppression remains constant within errors. The deficit is already apparent in semi-peripheral reactions and increases smoothly with centrality.
485 citations
TL;DR: In this article, several lagrange multiplier (LM) tests for the panel data regression model with spatial error correlation are presented. But the authors do not consider the presence of random regional effects.
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TL;DR: In this article, the causal relationship between economic growth and FDI and GDI in 80 countries over the period 1971-95, by using a panel VAR model, was investigated.
Abstract: The paper attempts to show causal relationships between economic growth and FDI and GDI in 80 countries over the period 1971-95, by using a panel VAR model. The results show that FDI Granger-causes economic growth, and vice versa; however, the effects are rather more apparent from growth to FDI than from FDI to growth. Also, GDI does not Granger-cause economic growth, but economic growth robustly Granger-causes GDI. These findings suggest that strong positive associations between economic growth and FDI inflows or GDI rates do not necessarily mean that high FDI inflows or GDI rates lead to rapid economic growth.
01 Mar 2003-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The PHENIX detector as mentioned in this paper is designed to perform a broad study of A-A, p-A and p-p collisions to investigate nuclear matter under extreme conditions, and is used to study systematic variations with species and energy as well as to measure the spin structure of the nucleon.
Abstract: The PHENIX detector is designed to perform a broad study of A-A, p-A, and p-p collisions to investigate nuclear matter under extreme conditions A wide variety of probes, sensitive to all timescales, are used to study systematic variations with species and energy as well as to measure the spin structure of the nucleon Designing for the needs of the heavy-ion and polarized-proton programs has produced a detector with unparalleled capabilities PHENIX measures electron and muon pairs, photons, and hadrons with excellent energy and momentum resolution The detector consists of a large number of subsystems that are discussed in other papers in this volume The overall design parameters of the detector are presented (C) 2002 Elsevier Science BV All rights reserved
TL;DR: It is shown that genes of the autonomous pathway, previously thought only to act independently of the environment as regulators of the floral repressor FLC, are centrally involved in mediating the effects of ambient temperature.
Abstract: Onset of flowering is controlled by environmental signals such as light and temperature. Molecular-genetic studies in Arabidopsis thaliana have focused on daily light duration, or photoperiod, and transient exposure to winter-like temperatures, or vernalization1. Yet ambient growth temperature, which is strongly affected by current changes in global climate2, has been largely ignored. Here, we show that genes of the autonomous pathway, previously thought only to act independently of the environment as regulators of the floral repressor FLC (ref. 1), are centrally involved in mediating the effects of ambient temperature. In contrast to wild-type plants and those mutant in other pathways, autonomous-pathway mutants flower at the same time regardless of ambient temperature. In contrast, the exaggerated temperature response of cryptochrome-2 mutants is caused by temperature-dependent redundancy with the phytochrome A photoreceptor. As with vernalization and photoperiod, ambient temperature ultimately affects expression of the floral pathway integrator FT.
TL;DR: In this article, the authors examined differences in Internet usage, Internet innovativeness, perceived risks of Internet buying, and Internet buying behaviors between Korea and America, and identified a model for factors influencing Internet buying behavior, explained by Internet usage and perceived risks on a cross-cultural basis.
Abstract: This research attempted to examine differences in Internet usage, Internet innovativeness, perceived risks of Internet buying, and Internet buying behaviors between Korea and America, and to identify a model for factors influencing Internet buying behavior, explained by Internet usage, perceived risks, and innovativeness on a cross‐cultural basis. Results showed that there were significant differences in Internet usage and the perceived risks of Internet shopping, but no significant differences in Internet buying intentions or online buying experience between Korean and American consumers. Nonetheless, analyzing a regression model of factors influencing Internet buying behavior, and cultural differences in effects of Internet usage and perceived risks on Internet buying behavior were found. While there were main effects of Internet usage and perceived risk on Internet buying behavior, these effects were weaker or even opposite to those related to Korean samples. The implications of the study are discussed and further research was suggested.
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TL;DR: In this paper, the critical values of the extended Kolmogorov-Smirnov tests of First and Second Order Stochastic Dominance in the general K-prospect case are estimated.
Abstract: We propose a procedure for estimating the critical values of the extended Kolmogorov- Smirnov tests of First and Second Order Stochastic Dominance in the general K-prospect case. We allow for the observations to be serially dependent and, for the first time, we can accommodate general dependence amongst the prospects which are to be ranked. Also, the prospects may be the residuals from certain conditional models, opening the way for conditional ranking. We also propose a test of Prospect Stochastic Dominance. Our method is subsampling; we show that the resulting tests are consistent and powerful against some N|1/2 local alternatives even when computed with a data-based subsample size. We also propose some heuristic methods for selecting subsample size and demonstrate in simulations that they perform reasonably. We show that our test is asymptotically similar on the entire boundary of the null hypothesis, and is unbiased. In comparison, any method based on resampling or simulating from the least favorable distribution does not have these properties and consequently will have less power against some alternatives.
TL;DR: The yield ratio does not show the suppression observed in central Au+Au collisions at RHIC, but there is a small enhancement in the yield of high momentum particles.
Abstract: Transverse momentum spectra of charged hadrons with p(T)<8 GeV/c and neutral pions with p(T)<10 GeV/c have been measured at midrapidity by the PHENIX experiment at BNL RHIC in d+Au collisions at sqrt[s(NN)]=200 GeV. The measured yields are compared to those in p+p collisions at the same sqrt[s(NN)] scaled up by the number of underlying nucleon-nucleon collisions in d+Au. The yield ratio does not show the suppression observed in central Au+Au collisions at RHIC. Instead, there is a small enhancement in the yield of high momentum particles.
TL;DR: The qualitative and quantitative differences in the cellular wound healing response after PRK for high and low myopia and LASIK for high myopia are likely determinants of the clinical differences in refractive outcome and some of the complications, such as regression and haze, seen after these procedures.
TL;DR: In this article, the causal relationship between economic growth and FDI and GDI in 80 countries over the period 1971-95, by using a panel VAR model, was investigated.
Abstract: The paper attempts to show causal relationships between economic growth and FDI and GDI in 80 countries over the period 1971–95, by using a panel VAR model. The results show that FDI Granger–causes economic growth, and vice versa; however, the effects are rather more apparent from growth to FDI than from FDI to growth. Also, GDI does not Granger–cause economic growth, but economic growth robustly Granger–causes GDI. These findings suggest that strong positive associations between economic growth and FDI inflows or GDI rates do not necessarily mean that high FDI inflows or GDI rates lead to rapid economic growth.
TL;DR: In this article, the first observation of the B-->D over barD(sJ)(2317) and B->D>D-s*gamma decays based on 123.8x10(6) B (B) was reported.
Abstract: We report the first observation of the B-->(D) over barD(sJ)(2317) and B-->(D) over barD(sJ)(2457) decays based on 123.8x10(6) B (B) over bar events collected with the Belle detector at KEKB. We observe the D-sJ(2317) decay to D(s)pi(0) and the D-sJ(2457) decay to the D(s)(*)pi(0) and D(s)gamma final states. We also set 90% C.L. upper limits for the decays D-sJ(2317)-->D-s*gamma, D-sJ(2457)-->D-s*gamma, D-sJ(2457)-->D(s)pi(0), and D-sJ(2457)-->D(s)pi(+)pi(-).
TL;DR: The cytokine-serotonin interaction that leads to the challenge between quinolinate and kynurenate in the brain explains the neurodegeneration hypothesis of depression.
TL;DR: In this article, the effect of edible coatings in combination with antibrowning agents on minimally processed apple slices was studied during storage at 3°C for 2 weeks, and the results showed that WPC (5.5g/100mL) containing ascorbic acid plus CaCl 2 (1g/ 100mL) was the most effective preservation treatment in terms of sensory quality after 2 week.
Abstract: Effect of edible coatings in combination with antibrowning agents on minimally processed apple slices was studied during storage at 3°C for 2 week. To control initial respiration rate of apple slices, edible coatings were applied to cut apples as semipermeable barriers against air. Initial respiration rate showed a decrease by 5% and 20% in carrageenan (0.5 g/100 mL)-coated and whey protein concentrate (5 g/100 mL)-coated apples, respectively, at 25°C. Edible coatings in combination with antibrowning agents effectively prolonged the shelf-life of minimally processed apple slices by 2 week when stored in packed trays at 3°C. Addition of various antibrowning agents to these coating solutions was advantageous in maintaining color during storage. Addition of CaCl 2 (1 g/100 mL) significantly inhibited the loss of firmness. These edible coatings in combination with antibrowning agents also showed positive sensory analysis results and beneficial reduction of microbial levels. WPC (5 g/100 mL) containing ascorbic acid (1 g/100 mL) plus CaCl 2 (1 g/100 mL) was the most effective preservation treatment in terms of sensory quality after 2 week.
TL;DR: A physician who performs RF ablation of hepatic malignancies should be aware of the broad spectrum of major complications so that these strategies can be used.
Abstract: Although radio-frequency (RF) ablation has been accepted as a promising and safe technique for treatment of unresectable hepatic tumors, investigation of its complications has been limited. According to the multicenter (1,139 patients in 11 institutions) survey data of the Korean Study Group of Radiofrequency Ablation, a spectrum of complications occurred after RF ablation of hepatic tumors. The prevalence of major complications was 2.43%. The most common complications were hepatic abscess (0.66%), peritoneal hemorrhage (0.46%), biloma (0.20%), ground pad burn (0.20%), pneumothorax (0.20%), and vasovagal reflex (0.13%). Other complications were biliary stricture, diaphragmatic injury, gastric ulcer, hemothorax, hepatic failure, hepatic infarction, renal infarction, sepsis, and transient ischemic attack. One procedure-related death (0.09%) occurred (due to peritoneal hemorrhage). Three important strategies for decreasing the rate of complications are prevention, early detection, and proper management. A ph...
TL;DR: Research measures phosphorus release and predicts future releases from bottom sediments of two tributary areas (Chungpyung Lake (CPL) and Jamsil submerged dam (JSD) area in the Han river) and shows that phosphorus release rates ranged from 60 to 80 mg/m2 week in JSD area and ranged from 25 to 40mg/m3 week in CPL sediments.
Journal Article•
TL;DR: The results show that neural activity in the prefrontal cortex changes dynamically during new task learning so that working memory is robustly represented and that worked memory can be mediated by sequential activation of different neural populations.
TL;DR: This is the first report that T-DNA insertional mutagenesis can be used for functional analysis of rice genes and two additional chlorina mutants that have a Tos17 insertion in the OsCHLH gene are identified.
Abstract: We have previously generated a large pool of T-DNA insertional lines in rice. In this study, we screened those T-DNA pools for rice mutants that had defective chlorophylls. Among the 1,995 lines examined in the T2 generation, 189 showed a chlorophyll-deficient phenotype that segregated as a single recessive locus. Among the mutants, 10 lines were beta-glucuronidase (GUS)-positive in the leaves. Line 9-07117 has a T-DNA insertion into the gene that is highly homologous to XANTHA-F in barley and CHLH in Arabidopsis: This OsCHLH gene encodes the largest subunit of the rice Mg-chelatase, a key enzyme in the chlorophyll branch of the tetrapyrrole biosynthetic pathway. In the T2 and T3 generations, the chlorina mutant phenotypes are co-segregated with the T-DNA. We have identified two additional chlorina mutants that have a Tos17 insertion in the OsCHLH gene. Those phenotypes were co-segregated with Tos17 in the progeny. GUS assays and RNA blot analysis showed that expression of the OsCHLH gene is light inducible, while TEM analysis revealed that the thylakoid membrane of the mutant chloroplasts is underdeveloped. The chlorophyll content was very low in the OschlH mutants. This is the first report that T-DNA insertional mutagenesis can be used for functional analysis of rice genes.
TL;DR: The invariant differential cross section for inclusive neutral-pion production in p+p collisions at roots=200 GeV has been measured at midrapidity (eta < 0.35) over the range 1
Abstract: The invariant differential cross section for inclusive neutral-pion production in p+p collisions at roots=200 GeV has been measured at midrapidity (eta<0.35) over the range 1
TL;DR: Results suggest that AEGRC might exert anti-diabetic effect by suppressing carbohydrate absorption from intestine, and thereby reducing the postprandial increase of blood glucose.
TL;DR: In this article, a peptide molecule, N-methylacetamide (NMA), when it is solvated by a few water molecules was investigated by carrying out ab initio calculations for a number of NMA-water complexes.
Abstract: Hydration effects on the molecular structure and amide I mode frequency of a prototype peptide molecule, N-methylacetamide (NMA), when it is solvated by a few water molecules, were investigated by carrying out ab initio calculations for a number of NMA–water complexes The harmonic frequency shift of the amide I mode in NMA–nD2O (n=1–5) complex was found to originate from the combination of the molecular cubic anharmonicity and displacement of the amide I coordinate when the NMA is hydrated Using a multivariate least-square fitting method, the effective transition charges of six NMA sites were determined A brief discussion on how this empirical model can be used to quantitatively describe solvatochromic frequency shift of the NMA amide I mode in solution is presented