3,462 research outputs found
Insolvency in the Corporate Sector and Financial Crisis in Korea
The paper shows that between the late 1980s and 1997, the year when Korea was engulfed in a financial crisis, its corporate-sector profitability was on a decreasing trend, albeit short-term ups and downs. The evidence presented in the paper suggests that Korea’s corporate and financial sectors had been highly vulnerable to a crisis for some years before 1997 and the actual timing of the crisis was triggered by the financial crisis in Thailand in July 1997 and its contagion effect.Asian crisis; Korean economy; corporate sector insolvency.
Direct and Indirect Detection of Neutralino Dark Matter and Collider Signatures in an Model with Two Intermediate Scales
We investigate the detectability of neutralino Dark Matter via direct and
indirect searches as well as collider signatures of an model with two
intermediate scales. We compare the direct Dark Matter detection cross section
and the muon flux due to neutralino annihilation in the Sun that we obtain in
this model with mSUGRA predictions and with the sensitivity of current and
future experiments. In both cases, we find that the detectability improves as
the model deviates more from mSUGRA. In order to study collider signatures, we
choose two benchmark points that represent the main phenomenological features
of the model: a lower value of and reduced third generation sfermion
masses due to extra Yukawa coupling contributions in the Renormalization Group
Equations, and increased first and second generation slepton masses due to new
gaugino loop contributions. We show that measurements at the LHC can
distinguish this model from mSUGRA in both cases, by counting events containing
leptonically decaying bosons, heavy neutral Higgs bosons, or like--sign
lepton pairs.Comment: 21 pages, 16 figure
Local Hall effect in hybrid ferromagnetic/semiconductor devices
We have investigated the magnetoresistance of ferromagnet-semiconductor
devices in an InAs two-dimensional electron gas system in which the magnetic
field has a sinusoidal profile. The magnetoresistance of our device is large.
The longitudinal resistance has an additional contribution which is odd in
applied magnetic field. It becomes even negative at low temperature where the
transport is ballistic. Based on the numerical analysis, we confirmed that our
data can be explained in terms of the local Hall effect due to the profile of
negative and positive field regions. This device may be useful for future
spintronic applications.Comment: 4 pages with 4 fugures. Accepted for publication in Applied Physics
Letter
Serum 25-hydroxyvitamin D levels and risk of colorectal cancer:an age-stratified analysis
Background and aims: the role of circulating 25-hydroxyvitamin D (25(OH)D) in prevention of early-onset colorectal cancer (CRC) in young adults under 50 years is uncertain. We evaluated the age-stratified associations (<50 vs. ≥50 years) :circulating 25(OH)D levels and the risk of CRC in a large sample of Korean adults.Methods: our cohort study included 236,382 participants (mean [standard deviation] age, 38.0 [9.0] years) who underwent a comprehensive health examination, including measurement of serum 25(OH)D levels. Serum 25(OH)D levels were categorized as follows: <10, 10–20, and ≥20 ng/mL. CRC, along with the histologic subtype, site, and invasiveness was ascertained through linkage with the national cancer registry. Cox proportional hazard models were used to estimate hazard ratios (HRs; 95% confidence intervals [CIs]) for incident CRC according to the serum 25(OH)D status, with adjustment for potential confounders.Results: during the 1,393,741 person-years of follow-up (median, 6.5 years; interquartile range, 4.5–7.5 years), 341 participants developed CRC (incidence rate, 19.2 per 105 person-years). Among young individuals aged <50 years, serum 25(OH)D levels were inversely associated with the risk of incident CRC with HRs (95% CIs) of 0.61 (0.43–0.86) and 0.41 (0.27–0.63) for 25(OH)D 10-19 and ≥20 ng/mL, respectively, with respect to the reference (<10 ng/mL) (p for trend <0.001, time-dependent model). Significant associations were evident for adenocarcinoma, colon cancer, and invasive cancers. For those aged ≥50 years, associations were similar, although slightly attenuated compared to younger individuals. Conclusions: serum 25(OH)D levels may have beneficial associations with the risk of developing CRC for both early-onset and late-onset disease. <br/
Higgs Structures of Dyonic Instantons
We study Higgs field configurations of dyonic instantons in spontaneously
broken (4+1)-dimensional Yang-Mills theory. The adjoint scalar field solutions
to the covariant Laplace equation in the ADHM instanton background are
constructed in general noncanonical basis, and they are used to study
explicitly the Higgs field configurations of dyonic instantons when the gauge
fields are taken by Jackiw-Nohl-Rebbi instanton solutions. For these solutions
corresponding to small instanton number we then consider in some detail the
zero locus of the Higgs field, which describes the cross section of supertubes
connecting parallel D4-branes in string theory. Also the information on the
Higgs zeroes is used to discuss the residual gauge freedom concerning the
Jackiw-Nohl-Rebbi solutions.Comment: 1+27 pages, 6 figure
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