• 대한수학회보
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• 제40권2호
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• pp.327-340
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• 2003

We are devoted to dealing with the conformal theory of a Rizza manifold with a generalized Finsler metric $G_{ij}$ (x,y) and a new conformal invariant non-linear connection $M^{i}$ $_{j}$ (x,y) constructed from the generalized Cern's non-linear connection $N^{i}$ $_{j}$ (x,y) and almost complex structure $f^{i}$ $_{j}$ (x). First, we find a conformal invariant connection ( $M_{j}$ $^{i}$ $_{k}$ , $M^{i}$ $_{j}$ , $C_{j}$ $^{i}$ $_{k}$ ) and conformal invariant tensors. Next, the nearly Kaehlerian (G, M)-structures under conformal change in a Rizza manifold are investigate.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1350-1358
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• 2008

Recently the study related to life cycle cost analysis of railway structure consisted of a complex is proceeded covering several range, which is considering the methodology of efficiency and rationalization for maintenance and analysing long-time behavior of the structure of looking at standpoint from asset management and safety. But LCCA(life cycle cost analysis) of railway structure was almost impossible as there were not anything datum for maintenance plan, such as maintenance periods related to each of components(painting and corrosion of steel, and cracking of elements, etc)and maintenance proportion, despite of its 100-year history. According, for collecting data related to railway truss bridge, bridge record cards and testing safety papers, and researching question, etc are surveyed and classified for LCC Analysis. Especially, LCC assessment on the side of assets-maintenance considering about initial cost, maintenance cost, and indirect cost is constructed. Maintenance period and complementary measure rate are very important in maintenance. To decide maintenance period, Baysian updating method is applied.

• ETRI Journal
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• 제26권4호
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• pp.315-320
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• 2004

This paper proposes a 10-${\mu}m$ thick oxide layer structure that can be used as a substrate for RF circuits. The structure has been fabricated using an anodic reaction and complex oxidation, which is a combined process of low-temperature thermal oxidation (500 $^{\circ}C$ for 1 hr at $H_2O/O_2$) and a rapid thermal oxidation (RTO) process (1050 ${\circ}C$, for 1 min). The electrical characteristics of the oxidized porous silicon layer (OPSL) were almost the same as those of standard thermal silicon dioxide. The leakage current density through the OPSL of 10 ${\mu}m$ was about 10 to 50 $nA/cm^2$ in the range of 0 to 50 V. The average value of the breakdown field was about 3.9 MV/cm. From the X-ray photo-electron spectroscopy (XPS) analysis, surface and internal oxide films of OPSL prepared by a complex process were confirmed to be completely oxidized. The role of the RTO process was also important for the densification of the porous silicon layer (PSL) oxidized at a lower temperature. The measured working frequency of the coplanar waveguide (CPW) type short stub on an OPSL prepared by the complex oxidation process was 27.5 GHz, and the return loss was 4.2 dB, similar to that of the CPW-type short stub on an OPSL prepared at a temperature of 1050 $^{\circ}C$ (1 hr at $H_2O/O_2$). Also, the measured working frequency of the CPW-type open stub on an OPSL prepared by the complex oxidation process was 30.5 GHz, and the return was 15 dB at midband, similar to that of the CPW-type open stub on an OPSL prepared at a temperature of $1050^{\circ}C$ (1 hr at $H_2O/O_2$).

• 대한수학회보
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• 제45권2호
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• pp.321-338
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• 2008

Let $\bar{M}$ be a smoothly bounded pseudoconvex complex manifold with a family of almost complex structures $\{L^{\tau}\}_{{\tau}{\in}I}$, $0{\in}I$, which extend smoothly up to bM, the boundary of M, and assume that there is ${\lambda}{\in}C^{\infty}$(bM) which is strictly subharmonic with respect to the structure $L^0|_{bM}$ in any direction where the Levi-form vanishes on bM. We obtain explicit estimates for the $\bar{\partial}$-Neumann problem in Sobolev spaces both in space and parameter variables. Also we get a similar result when $\bar{M}$ is strongly pseudoconvex.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.851-857
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• 2014

Carotenoids, natural antenna pigments in photosynthesis share a symmetric backbone of conjugated polyenes. Contrary to the symmetric and almost planar geometries of carotenoids, excited state structure and dynamics of carotenoids are exceedingly complex. In this paper, recent infrared and visible transient absorption measurements and excitation dependent dynamics of 8'-apo-${\beta}$-caroten-8'-al and 7',7'-dicyano-7'-apo-${\beta}$-carotene will be reviewed. The recent visible transient absorption measurements of 8'-apo-${\beta}$-caroten-8'-al in polar and nonpolar solvents will also be introduced to emphasize the complex excited-state dynamics and unsolved problems in the $S_2$ and $S_1$ excited states.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.358-365
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• 2000

For the general case of loading conditions and boundary conditions, it is very difficult to obtain closed form solutions for buckling loads and natural frequencies of thin-walled structures because its behaviour is very complex due to the coupling effect of bending and torsional behaviour. In consequence, most of previous finite element formulations are introduce approximate displacement fields to use shape functions as Hermitian polynomials, and so on. The Purpose of this study is to presents a consistent derivation of exact dynamic stiffness matrices of thin-walled straight beams, to be used ill tile free vibration analysis, in which almost types of boundary conditions are exist An exact dynamic element stiffness matrix is established from governing equations for a uniform beam element of nonsymmetric thin-walled cross section. This numerical technique is accomplished via a generalized linear eigenvalue problem by introducing 14 displacement parameters and a system of linear algebraic equations with complex matrices. The natural frequency is evaluated for the thin-walled straight beam structure, and the results are compared with analytic solutions in order to verify the accuracy of this study.

• Bulletin of the Korean Chemical Society
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• 제21권5호
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• pp.510-514
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• 2000

Molecular hydrogen dimer, ($H_2)_2$ is a weakly bound van der Waals complex. The configuration of two hydrogen molecules and the potential well structure of the dimer have been the subjects of various studies among chemists and astrophysicists. In this study, we used DFT, MCG2, and MCG3 methods to determine the structure and energy of the molecular hydrogen dimer. We compared the results with previously reported ab initio method results. The ab initio results were also recalculated for comparison. All optimized geometries obtained from the MP2 and DFT methods are T-shaped. The H-H bond lengths for the dimer are almost the same as those of monomer. The center-to-center distance depeds on the levels of theory and the size of the basis sets. The bond lengths of the $H_2$ molecule from the MCG2 and MCG3 methods are shown to be in excellent agreement with the experimental value. The geometry of optimized dimer is T-shaped, and the well depths for the dimerization potential are very small, being 23 $cm-^1$ and 27 $cm-^1$ at the MCG2 and MCG3 levels, respectively. In general the MP2 level of theory predicts stronger van der Waals than the DFT, and agrees better with the MCG2 and MCG3 theories.

• ETRI Journal
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• 제37권1호
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• pp.43-53
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• 2015

In this paper, a selective coefficient updating (SCU) approach at each branch of the per-tone equalization (PTEQ) structure has been applied for insufficient cyclic prefix (CP) length. Because of the high number of adaptive filters and their complex adaption process in the PTEQ structure, SCU has been proposed. Using this method leads to a reduction in the computational complexity, while the performance remains almost unchanged. Moreover, the use of set-membership filtering with variable step size is proposed for a sufficient CP case to increase convergence speed and decrease the average number of calculations. Simulation results show that despite the aforementioned algorithms having similar performance in comparison with conventional algorithms, they are able to reduce the number of calculations necessary. In addition, compensation of both the channel effect and the transmitter/receiver in-phase/quadrature-phase imbalances are achievable by these algorithms.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2004년도 학술발표논문집
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• pp.79-84
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• 2004

We use principal component analysis (PCA) to identify exons of a gene and further analyze their internal structures. The PCA is conducted on the short-time Fourier transform (STFT) based on the 64 codon sequences and the 4 nucleotide sequences. By comparing to independent component analysis (ICA), we can differentiate between the exon and intron regions, and how they are correlated in terms of the square magnitudes of STFTs. The experiment is done on the gene F56F11.4 in the chromosome III of C. elegans. For this data, the nucleotide based PCA identifies the exon and intron regions clearly. The codon based PCA reveals a weak internal structure in some exon regions, but not the others. The result of ICA shows that the nucleotides thymine (T) and guanine (G) have almost all the information of the exon and intron regions for this data. We hypothesize the existence of complex exon structures that deserve more detailed analysis.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.132-137
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• 1993

The electronic structure of two dimensional layered compound, FeOCl, is studied with the band model and the cluster model approximation employing Extended-Huckel (EH) method. We examine the effects of intercalation (e.g., localization of transferred electron, conductivity increase). FeOCl has the electronic structure typical for layered compounds as expected. For FeOCl-$Li_{1/2}$ system, the charge transfer from Li to the FeOCl lattice occurs, and electrons are built up almost exclusively on Fe atoms. The partially filled band of FeOCl-$Li_{1/2}$ complex is responsible for the increase in conductivity.