• 대한화학회지
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• 제56권2호
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• pp.195-200
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• 2012

In this study we present a new approach for computing the partial atomic charge derived from the wavefunctions of molecules. This charge, which we call the "y_charge", was calculated by taking into account the energy level and orbital populations in each molecular orbital (MO). The charge calculations were performed in the software, which was developed by us, developed using the C# programming language. Partial atomic charges cannot be calculated directly from quantum mechanics. According to a partitioning function, the electron density of constituent molecular atoms depends on the electrostatic attraction field of the nucleus. Taking into account the Boltzmann population of each MO as a function of its energy and temperature we obtain a formula of partial charges.

• Archives of Plastic Surgery
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• 제35권6호
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• pp.675-679
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• 2008

Purpose: In the orbital floor fracture, sensory impairment due to the damage of the infraorbital nerve is one of the most common symptom and complication. In this report, we have the assumption that tailoring of $medpor^{(R)}$ for decompression may have correlations to the damage and regeneration of the nerve. Methods: Among patients who had open reduction for pure orbital floor fracture in our hospital from March 2005 to March 2008, we selected 80 cases. In 40 cases, we inserted tailored $medpor^{(R)}$, and in other 40 cases, non-tailored $medpor^{(R)}$ was inserted. Patient's reports were obtained and analyzed, and the pin-prick test and the 2-point discrimination test on the infraorbital nerve regions were done for testing the sensory impairments. Results: The results show that the patients who adopted sculpture of $medpor^{(R)}$ showed higher tendency of recovery of sensory impairments in the patient's subjective report, static touch sensation, static two point discrimination using. And in postoperative 3 months, there are statistically significant recovery of sensory symptoms, signs and the result of sensory tests. Conclusion: From these results, tailored $medpor^{(R)}$ in reconstruction of orbital wall fracture may improve recovery of sensory impairments for decreasing of compression of infraorbital nerve.

• 천문학회보
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• 제35권1호
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• pp.52.1-52.1
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• 2010

The relationship between orbital periods of cataclysmic variables (CV) and mass-loss rates of their donor stars is an important subject of theoretical researches. The observed donor's radii are oversized in comparison with those of isolated unperturbed stars of the same mass, which is thought to be a consequence of the mass-loss. Using the empirical mass-radius relation of CVs and the Hayashi theory for changes in effective temperature, orbital period, and luminosity of the donor with the stellar radius, we find the mass-loss rate of CVs as a function of the orbital period P. The derived mass-loss rate is more or less constant at 10-9.6-10-10M$\odot$ yr-1 with P above 90 minutes and declines very rapidly with P below 90 minutes, reaching 10-10.3-10-11.7M$\odot$ yr-1 when P is close to the minimum period. The turnaround behavior of the mass-loss rate shape with P near the minimal period is much less pronounced than suggested by earlier numerical models, making observational detection of the turnaround highly unlikely. When applied to our new results, SDSS 1035, 1507, 1501 and 1433 systems, previously known as post-bounce CVs, are more likely to be systems that have yet to reach the minimal period.

• 대한수학회지
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• 제37권5호
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• pp.657-664
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• 2000

A new concept of stability that includes Lyapunov and orbital stabilities and leads to concepts in between them is discussed in terms of a given topology of the function space. The criteria for such new concepts to hold are investigted employing suitably Lyapunov-like functions and the comparison principle.

• Progress in Superconductivity
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• 제11권2호
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• pp.135-140
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• 2010

We propose a variational wave function for the ground state of the magnetic heavy fermion (HF) systems, in which both the Kondo and the RKKY interactions are variationally incorporated and the local f-orbital state exists as a linear combination of a full local moment state and a fully compensated state (mixed wave state). We describe the mechanism for the mixed wave ground state based on the large-N treatment of the Kondo lattice Hamiltonian added with RKKY interaction. With the mixed wave ground state we can explain several puzzling experiments in magnetic HF compounds such as a small value of local moment, coexistence of the antiferromagnetic (AFM) and the paramagnetic (PM) phases, local quantum criticality, etc.

• 한국염색가공학회지
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• 제21권5호
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• pp.35-40
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• 2009

Computational calculations of molecular orbital and electrochemical redox/oxidation potentials are of very importance to determine the compound properties. The energy levels of molecular orbital were calculated by the density function theory (DFT) with exchange correction functional of local density approximation (LSA) based on the Perdew-Wang (PWC) setting and cyclic voltammetry.

• Bulletin of the Korean Chemical Society
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• 제16권10호
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• pp.915-923
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• 1995

The parameters for an empirical net atomic charge calculation method, Modified Partial Equalization of Orbital Electronegativity (MPEOE), were determined for the atoms in organosilicon compounds and zeolites. For the organosilicon family, the empirical parameters were determined by introducing both experimental and ab initio observables as constraints, these are the experimental and ab initio dipole moments, and the ab initio electrostatic potential of the organosilicon molecules. The Mulliken population was also introduced though it is not a quantum mechanical observable. For the parameter optimization of the atoms in the aluminosilicates, the dipole moments and the electrostatic potentials which calculated from the 6-31G** ab initio wave function were used as constraints. The empirically calculated atomic charges of the organosilicons could reproduce both the experimental and the ab inito dipole moments well. The empirical atomic charges of the aluminosilicates could reproduce the ab initio electrostatic potentials well also.

• Journal of Astronomy and Space Sciences
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• 제22권4호
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• pp.353-362
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• 2005

2004년 3월 25일부터 4일 동안 보현산천문대의 1.8m 망원경과 BOES(Bohyunsan Optical Echelle Spectrograph)를 사용하여 AG Vir의 고분산 분광관측을 수행하고, 전위상에 걸쳐 총 59개의 스펙트럼을 얻었다. 쌍성계의 시선속도를 얻기 위하여, 교차상관함수(CCF; Cross-Correlation Function) 와 선폭증가함수(BF; Broadening Function)를 관측된 스펙트럼의 분석에 사용하였다. 이때, 교차상관함수 분석을 통하여 주성의 시선속도만을 얻을수 있었던 반면, 선폭증가함수 분석을 통하여 두 성분별의 시선속도를 모두 구할 수 있었다. 우리는 분광 궤도요소($K_1=90.5km/s$와 $K_2=258.8km/s$)와 Bell, Rainger, & Hilditch(1990)의 측광학적 해로부터 AG Vir의 절대 물리량을 다음과 같이 산출하였다. 즉, $M_1:1.99M_\bigodot,\;M_2:0.62M_\bigodot,\; R_1=2.21R_\bigodot,\;R_2=1.36R_\bigodot,\;L_1=13.17L_\bigodot$, 그리고 $L_2=3.47L_\bigodot$. 우리가 구한 각 성분별의 질량과 반경은 Bell, Rainger, & Hilditch(1990)의 값보다 더 크고, 광도 또한 더 밝다. 발표된 모든 시선속도곡선을 재분석한 결과, AG Vir의 시스템 속도는 약 ${\pm}8km/s$의 비교적 큰 편차를 나타낸다. 그러나 이 변화가 Qian(2001)이 제안한 제3 천체의 광시간 효과에 의해 일어난다고 단정 지을 수 있는 근거를 찾을 수는 없었다.

• Fisheries and Aquatic Sciences
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• 제22권6호
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• pp.12.1-12.8
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• 2019

Background: Wild fish populations stock is continuously diminishing in the Indo-Ganges river basin, and the population status of most fishes is unidentified. The identification of the population status and the conservation of commercially important and endemic wild fish populations in this region are crucial for the management. The aim of this paper was to identify the population status of Cirrhinus reba, a promising aquaculture but vulnerable species in the Indo-Ganges river basin in Bangladesh. Methods: C. reba samples were collected from four isolated populations of the Brahmaputra (n = 30), the Padma (33), the Karatoya (31), and the Jamuna Rivers (30) in Bangladesh, and the population status was evaluated using morphometric and landmark comparisons. Data were analyzed with the Kruskal-Wallis test, univariate analysis, discriminant function analysis, and the formation of a dendrogram. Results: Three meristic characters (Pectoral fin rays, caudal fin rays, scale in lateral lines), four morphometric characters (head length, pre-orbital length, post-orbital length, maximum body depth), and truss measurement (4-7) were significantly different among the stocks. The step-wise discriminant function analysis retained 15 variables from morphometric and landmark measurements that significantly differentiated the populations based on the constructed DFI and DFII. Discriminate function analysis also showed that 91.2% of the original groups were classified into their correct samples. The cluster analysis of Euclidean distances placed the Jamuna population in one cluster and the Brahmaputra, the Padma, and the Karatoya populations in the second one. Conclusion : Morphological differences among the stock were probably due to different ancestral origin. This is the first report about population status of C. reba in their natural habitat of the Indian subcontinent. Further genetic studies and the evaluation of environmental impact on C. reba populations in Bangladesh are suggested to support our findings.

• 한국항공우주학회지
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• 제45권10호
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• pp.881-891
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• 2017

본 논문에서는 인공위성의 궤도예측을 위해 사용되는 미국 합동우주관제센터(JSpOC, Joint Space Operation Center)의 TLE(Two Line Element) 정보에 대한 SGP4(Simplified General Perturbations 4) 모델의 장기 궤도예측 오차를 줄이기 위해 과거의 TLE 정보들을 이용한 보상기법을 적용하여 새로운 TLE 정보를 생성하는 방법에 대해 기술하고 있다. 이를 위해 과거 특정 시점에서의 TLE 정보를 바탕으로 현재까지 궤도전파를 한 데이터와 동일기간 동안 미국 합동우주관제센터에서 공개된 모든 TLE를 이용해서 궤도전파를 수행한 데이터를 비교하여 계산한 궤도잔차를 이용하였다. 이러한 궤도잔차 성분은 SGP4 궤도전파 모델에 의한 궤도오차 증가 경향을 보여주고 있기 때문에 궤도오차 보정을 위해 해당 궤도잔차 성분들을 적절한 함수로 표현하였다. 이후, 현재 시점에서 공개된 TLE 정보를 이용한 SGP4 궤도전파 데이터에 해당 잔차함수를 적용함으로써 장기 궤도전파에 따른 SGP4 모델의 궤도오차를 줄일 수 있었으며, 이를 바탕으로 새로운 TLE 정보를 생성하였다. 본 논문에서 일주일의 궤도전파에 대한 시뮬레이션을 통해 기존의 TLE를 이용한 궤도전파 오차가 4km 정도인 반면 새로운 TLE 생성기법에 의한 궤도전파 오차가 약 2km 수준으로 줄어드는 것을 확인할 수 있었다.