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31.
Kwangseok Choe Namkwon Kim Chang-Shou Lin 《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2011,28(6):837
In this paper we investigate the existence of non-topological solutions of the Chern–Simons Higgs model in R2. A long standing problem for this equation is: Given N vortex points and β>8π(N+1), does there exist a non-topological solution in R2 such that the total magnetic flux is equal to β/2? In this paper, we prove the existence of such a solution if . We apply the bubbling analysis and the Leray–Schauder degree theory to solve this problem. 相似文献
32.
33.
Namkung W. Choe J.Y. Uhm H.S. Ayres V. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1988,16(2):149-154
Microwave radiation at the fundamental and harmonic electron cyclotron frequencies generated by a cusptron oscillator is reported. A low-energy, axis-rotating beam of 28-30 kV, 0.8-3.5 A, 4 μs, and 60 pps interacts with a single RF mode, both in a circular cavity and in a six-vane circuit by the negative mass instability. In fundamental and second-harmonic frequency generation with a circular circuit, the independently excited modes are TE11s and TE21s, with radiation power of more than 1.8 kW and an electronic efficiency of approximately 7.5%. Employing a six-vane circuit, microwave radiation of 6.0 GHz (sixth harmonic) and 3.9 GHz (fourth harmonic) is also independently generated with more than 10.4 and 4.0 kW radiation power, respectively. Corresponding electronic efficiencies are approximately 10.0 and 9.5% 相似文献
34.
Choe JC 《The journal of physical chemistry. A》2006,110(15):4979-4984
The unimolecular dissociation of isopropyl chloride cation has been investigated using mass-analyzed ion kinetic energy spectrometry. The C3H6*+ ion was the only product ion in the metastable dissociation. The kinetic energy release distribution for the HCl loss was determined. Ab initio molecular orbital calculations were performed at the MP2/6-311++G(d,p) level together with single point energy calculations at the QCSID(T)/6-311++G(2d,2p) level. The calculations show that the molecular ion rearranges to an ion-dipole complex prior to loss of HCl via a transition state containing a four-membered ring. The rearrangement involves H atom transfer. On the basis of the potential energy surface obtained for the loss of HCl and Cl*, the rate constants were calculated by transition-state statistical theories with considering tunneling effect. From the calculated result, it is proposed that the observed HCl loss would occur via tunneling through the barrier for isomerization to the ion-dipole complex, CH3CHCH2*+...HCl. 相似文献
35.
Chang‐Hyuk Choi Hong‐Tae Kim Jung‐Yoon Choe Seong‐Kyu Kim Gi‐Whan Choi SangHoon Jheon Jong‐Ki Kim 《Journal of synchrotron radiation》2010,17(3):393-399
In vivo microstructures of the affected feet of collagen‐induced arthritic (CIA) mice were examined using a high‐resolution synchrotron radiation (SR) X‐ray refraction technique with a polychromatic beam issued from a bending magnet. The CIA models were obtained from six‐week‐old DBA/1J mice that were immunized with bovine type II collagen and grouped as grades 0–3 according to a clinical scoring for the severity of arthritis. An X‐ray shadow of a specimen was converted into a visual image on the surface of a CdWO4 scintillator that was magnified using a microscopic objective lens before being captured with a digital charge‐coupled‐device camera. Various changes in the joint microstructure, including cartilage destruction, periosteal born formation, articular bone thinning and erosion, marrow invasion by pannus progression, and widening joint space, were clearly identified at each level of arthritis severity with an equivalent pixel size of 2.7 µm. These high‐resolution features of destruction in the CIA models have not previously been available from any other conventional imaging modalities except histological light microscopy. However, thickening of the synovial membrane was not resolved in composite images by the SR refraction imaging method. In conclusion, in vivo SR X‐ray microscopic imaging may have potential as a diagnostic tool in small animals that does not require a histochemical preparation stage in examining microstructural changes in joints affected with arthritis. The findings from the SR images are comparable with standard histopathology findings. 相似文献
36.
For a vector bundle V of rank n over a curve X and for each integer r in the range 1 ≤ r ≤ n ? 1, the Segre invariant s r is defined by generalizing the minimal self-intersection number of the sections on a ruled surface. In this paper we generalize Lange and Narasimhan’s results on rank 2 bundles which related the invariant s 1 to the secant varieties of the curve inside certain extension spaces. For any n and r, we find a way to get information on the invariant s r from the secant varieties of certain subvariety of a scroll over X. Using this geometric picture, we obtain a new proof of the Hirschowitz bound on s r . 相似文献
37.
Hyejin Ku 《Applied Mathematical Finance》2013,20(2):131-141
This paper concerns questions related to the regulation of liquidity risk, and proposes a definition of an acceptable portfolio. Because the concern is with risk management, the paper considers processes under the physical (rather than the martingale) measure. Basically, a portfolio is ‘acceptable’ provided there is a trading strategy (satisfying some limitations on market liquidity) which, at some fixed date in the future, produces a cash‐only position, (possibly) having positive future cash flows, which is required to satisfy a ‘convex risk measure constraint’. 相似文献
38.
Recently Choe et al. have introduced the notion of dual Berezin transforms and used it to obtain new characterizations of the Carleson measures for the weighted Bergman spaces over the unit ball in C n . Continuing our investigation on the Hardy spaces, we obtain new characterizations of the Carleson measures for the Hardy spaces by means of the dual Poisson–Szegö transforms introduced by Koosis. Compared with the results for the weighted Bergman spaces, our results for the Hardy spaces not only show an similarity, but also reveal a new characterization. 相似文献
39.
Kab-Jin Kim Jae-Chul Lee Kyung-Ho Shin Hyun-Woo Lee Sug-Bong Choe 《Current Applied Physics》2013,13(1):228-236
Magnetic domain-wall (DW), interface between different magnetic domains, has received great attention due to its opportunities toward memory and logic devices as well as its abundant physical properties as a driven interface. Since recent advances of fabrication techniques allow us to scale down the devices, we are facing lower dimensional properties that should be elucidated undoubtedly. Here, we review recent progresses on DW dynamics in ferromagnetic nanowires and our recent experimental observation on the dimensionality transition of the DW dynamics driven by magnetic field and/or current. Our results show that the DW dynamics shows a transition from two to one dimensional behavior as the wire width decreases. In addition, we also demonstrate that the magnetic-field- and electric-current-driven DW dynamics in metallic ferromagnetic nanowires belong to the same universal class. 相似文献
40.
Seung-Man Yu Seung-Hong Choi Sae-Sark Kim Eun-Hoe Goo Youn-Sang Ji Bo-Young Choe 《Current Applied Physics》2013,13(5):857-863
The optimal volume of contrast medium must be injected into the patient who emits the maximum signal intensity in an ROI. This study was investigated four different type MRI and one CT contrast agent in vitro and sought to establish relations between concentration, MRI relaxivity, CT Hounsfield unites selected kVp and different MRI T1 sequences. Using a CT contrast medium and four different MRI T1 contrast media, we developed five different phantom series. The MRI contrast media phantom was imaged on 1.5T and 3T MRI systems and measured the R1 and R2 value. A CT scanner was used to obtain images of the Iopromide 370 phantom with the quality of radiation to obtain images. The Pearson's correlation coefficient analyses were conducted between MRI CM phantom series with Iopromide 370 phantom. The non-parametric statistical analyses were performed for the values of kVp. The ΔHU of the test solution of the CT contrast media was produced in the same amount as the exponentially increased concentration of the MRI contrast media according to the increase in the dilution concentration, and was influenced by the quality of the X-ray. Through the results of this experiment that considered the two aforementioned factors, an image with a high diagnosis value can be acquired from the information on the concentration of the MRI T1 contrast media. 相似文献