• 대한수학회지
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• 제40권4호
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• pp.609-627
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• 2003

In this paper we describe the Einstein-Kahler metric for the Cartan-Hartogs of the first type which is the special case of the Hua domains. Firstly, we reduce the Monge-Ampere equation for the metric to an ordinary differential equation in the auxiliary function X = X(z, w) = $\midw\mid^2[det(I-ZZ^{T}]^{\frac{1}{K}}$ (see below). This differential equation can be solved to give an implicit function in Χ. Secondly, we get the estimate of the holomorphic section curvature under the complete Einstein-K$\ddot{a}$hler metric on this domain.

• Journal of Astronomy and Space Sciences
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• 제28권2호
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• pp.123-132
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• 2011

It is generally believed that the occurrence of a magnetic storm depends upon the solar wind conditions, particularly the southward interplanetary magnetic field (IMF) component. To understand the relationship between solar wind parameters and magnetic storms, variations in magnetic field polarity and solar wind parameters during magnetic storms are examined. A total of 156 storms during the period of 1997~2003 are used. According to the interplanetary driver, magnetic storms are divided into three types, which are coronal mass ejection (CME)-driven storms, co-rotating interaction region (CIR)-driven storms, and complicated type storms. Complicated types were not included in this study. For this purpose, the manner in which the direction change of IMF $B_y$ and $B_z$ components (in geocentric solar magnetospheric coordinate system coordinate) during the main phase is related with the development of the storm is examined. The time-integrated solar wind parameters are compared with the time-integrated disturbance storm time (Dst) index during the main phase of each magnetic storm. The time lag with the storm size is also investigated. Some results are worth noting: CME-driven storms, under steady conditions of $B_z$ < 0, represent more than half of the storms in number. That is, it is found that the average number of storms for negative sign of IMF $B_z$ (T1~T4) is high, at 56.4%, 53.0%, and 63.7% in each storm category, respectively. However, for the CIR-driven storms, the percentage of moderate storms is only 29.2%, while the number of intense storms is more than half (60.0%) under the $B_z$ < 0 condition. It is found that the correlation is highest between the time-integrated IMF $B_z$ and the time-integrated Dst index for the CME-driven storms. On the other hand, for the CIR-driven storms, a high correlation is found, with the correlation coefficient being 0.93, between time-integrated Dst index and time-integrated solar wind speed, while a low correlation, 0.51, is found between timeintegrated $B_z$ and time-integrated Dst index. The relationship between storm size and time lag in terms of hours from $B_z$ minimum to Dst minimum values is investigated. For the CME-driven storms, time lag of 26% of moderate storms is one hour, whereas time lag of 33% of moderate storms is two hours for the CIR-driven storms. The average values of solar wind parameters for the CME and CIR-driven storms are also examined. The average values of ${\mid}Dst_{min}{\mid}$ and ${\mid}B_{zmin}{\mid}$ for the CME-driven storms are higher than those of CIR-driven storms, while the average value of temperature is lower.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1482-1487
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• 2003

This paper presents a new family of 4-DoF parallel mechanism with two platforms. The new mechanism is composed of front and rear platforms, and three limbs. Two limbs with 6dof joint (P-P-S-P) are attached to the each platform and are perpendicular to baseplate, while the middle limb with 4-Dof joints (R-R-R-P or R-R-P-P) is attached to the revolute joint that connect front and rear platform. The two-DoF-driving mechanism at the middle limb with two base-fixed prismatic actuators can generate the heaving and roll motions or two translational motions. Therefore, Therefore, the new 4-Dof parallel mechanism (1T-3R) can generate pitch motions at each platforms, roll, and heaving motions, while another type of new 4-Dof parallel mechanism (2T-2R) can generate pitch motions at each platforms, x and z translational motions. For 1T-3R mechanism, kinematic analyses including inverse, forward kinematics, and Jacobian are performed.

• The Korean Journal of Ecology
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• 제28권2호
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• pp.69-77
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• 2005

1998년 3월부터 2003년 9월까지 남해도 및 인접도서를 포함하는 남해군의 삼림식생에 대해 Z.-M.방법에 의한 식물사회학적 조사를 실시하였다. 그 결과 본 조사지역의 삼림식생은 신갈 나무군락(전형하위군락, 철쭉꽃하위군락), 졸참나무군락(전형하위군락, 당단풍하위군락), 굴참나무군락(전형하위군락, 굴피나무하위군락), 상수리나무군락, 서어나무군락, 소사나무군락, 때죽나무군락, 느티나무군락, 히어리군락, 소나무군락(전형하위군락, 진달래하위군락, 서어나무하위군락), 곰솔군락(전형하위군락, 사스레피나무하위군락), 산철쭉군락, 편백식재림, 사방오리식재림, 리기다소나무식재림, 아까시나무식재림, 삼나무식재림 등 총 12군락, 11하위군락, 5식재림으로 구분되었다. 본 조사지역 삼림의 토양분석결과 삼림토양의 pH는$4.2\sim5.4$의 범위를 나타내었으며, 함수량은 유기물함량과 유의성이 높은 가운데 산철쭉군락이 가장 높고, 소나무군락이 가장 낮게 나타났다. 유기물함량은 신갈나무군락, 소사나무군락, 졸참나무군락에서 비교적 높게$(15.8\sim19.1%)$ 나타났고, 상수리나무군락, 히어리군락, 곰솔군락에서는 낮게$(3.3\sim5.4%)$ 나타났다. 식재림은 대부분 낮았으며. 리기다소나무식재림(2.8%)과 삼나무식재림(5.6%)이 가장 낮았다. 치환성 양이온($K^+$, $Ca^{2+}$ and $Mg^{2+}$)사이에는 높은 상관관계가 있는 것으로 나타났다.

• Restorative Dentistry and Endodontics
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• 제28권5호
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• pp.402-408
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• 2003

This study was done to present a criterion in selection of the most proper light sources and materials by measuring metamerism index(MI) of the light curing composite resins with spectrocolorimeter. Metamerism is defined when two objects appear to be the same color in one illuminant but different in another. This is due to the fact that they have different spectral curves that fail to match under the second illuminant. In this study, A1 & A3 shade of five light curing composite resins (Esthet-X, Filteck Z250, Filteck A110. Charisma. Vitalescence) were chosen based on Vita shade. Five samples were made for shade of each product with Teflon mold (diameter: 15mm, thickness: 2mm). Metamerism index of each samples on a Barium sulfate plate($L^{*}=96.54,{\;}a^{*}=0.19,{\;}b^{*}=0.01$) prepared for sample fixation were measured with spectrocolorimeter(Miniscan XE plus. Model 4000s. Hunter Lab. USA) by applying standard light source D^{65}, C. Fcw, TL84 and A. Standardization was done with reference standard(X=80.8, Y=85.7, Z=90.8) and light trap. The results were as follows. 1. Different resins with same Vita shade showed recognizable color difference (${\delta}E^{*}>2$). 2. All composites had MI below accepted value 0.5 between standard illuminant(D$_{65}$, C, & A) and below 1.5 under fluorescent condition (Fcw & TL84). 3. MI value between $D^{65}$ and A showed higher value than MI value between other source of light(p<0.01). 4. All resins except Z250 showed MI value that A3 is higher than A1 between $D^{65}$ and A(p<0.05).except Z250 showed MI value that A3 is higher than A1 between $D^{65}$ and A(p<0.05).

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.976-983
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• 2003

Seven Escherichia coli cells defective with aerobic growth were isolated by the insertion of ${\lambda}placMu53$, a hybrid bacteriophage of ${\lambda}$ and Mu, which created a transcriptional fusion to lacZY. These insertion mutant cells were tested on an XG ($5-bromo-4-chloro-3-indolyl-{\beta}-D-galactopyranoside$) medium for anaerobic expression of lacZ by fusion to a promoter. The chromosomal DNA from these strains were digested by EcoRI, and the EcoRI fragments that contained the fused gene and lacZ sequence were identified by Southern hybridization, using lacZ containing plasmid as a probe. The EcoRI fragment from each strain was cloned and sequenced. The sequence data were compared with the GenBank database. The mutated gene of three strains, CYT4, CYT5, and OS11, was found to be identical, and it was nrdAB that encoded ribonucleoside diphosphate reductase. The gene nrdAB was at min 50.5 on the Escherichia coli linkage map and 2,348,084 on the physical map, and is involved in hemAe-related reduction-oxidation reaction. OS6 and OS14 mutant strains had insertion at min 8.3 and the mutated gene was hemB. The hemB encodes 5-aminolevulinate dehydratase or porphobilinogen synthase. The OS3 mutant had insertion in cydB at min 16.6. The cydAB encodes cytochrome d oxidase. In the case of OS1, the fusion was made with sucA, the E1 component of ${\alpha}-ketoglutarate$ dehydrogenase.

• 한국어류학회지
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• 제17권1호
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• pp.73-83
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• 2005

2003년 7월부터 2004년 5월까지 의암호의 어류상 및 어류군집의 동태를 연구한 결과는 다음과 같다. 조사된 어류는 총 13과 41종 4,706개체이었다. 한국 고유종은 각시붕어 (R. uyekiid)을 포함하여 줄납자루 (A. yamatsutae), 중고기 (S. nigripinis morii), 긴몰개 (S. gracilis majimae), 몰개 (S. japonicus coreanus), 돌마자 (M.yaluensis), 참종개 (I. koreensis), 새코미꾸리 (K. rotundicaudata), 미유기 (Silurus microdorsalis), 퉁가리 (L. andersoni), 동사리 (O. platycephala) 등 11종 (26.8%)이었다. 우점종은 누치 (H. labeo) 16.2%, 피라미 (Z. platypus) 13.8%, 줄납자루 (A. yamatsutae) 11.8%, 긴몰개 (S.gracilis majimae) 10.4%, 돌고기 (P. herzi) 5.8%, 빙어 (H.olidus) 4.3% 등이었다. 채집된 어종들의 생체량을 살펴보면 총 92,057.6 g이 채집되었고 누치 (H. labeo)가 35,868.8 g (39.0%)으로 가장 많았으며 다음은 잉어 (C.carpio) 22,471 g (24.4%), 큰입우럭(M. salmoides) 5,446.7 g (5.9%), 파랑볼우럭 (L. macrochirus) 5,163.0 g (5.6%), 떡붕어 (C. cuvieri) 3,328.0 g (3.6%), 피라미 (Z. platypus) 2,537.4 g (2.8%) 등의 순으로 나타났다. 의암호에서 확인된 도입종은 뱀장어 (A. japonica), 빙어 (H. olidus), 꾹저구 (C. urotaenius), 갈문망둑 (R.giurinus), 이스라엘잉어 (C. carpio (Israeli type)), 떡붕어 (C. cuvieri), 무지개송어 (S. gairdneri irideus), 파랑볼우럭 (L. macrochirus), 큰입우럭 (M. salmoides) 등 9종이었다. 이 중 이스라엘잉어 (C. carpio (Israeli type)), 떡붕어 (C. cuvieri), 무지개송어 (S. gairdneri irideus), 파랑볼우럭(L. macrochirus), 큰입우럭(M. salmoides)은 국외종이며, 뱀장어 (A. japonica), 빙어 (H. olidus), 꾹저구 (C. urotaenius), 갈문망둑 (R. giurinus)은 국내 다른 수계로부터 도입된 종이다.

• 한국세라믹학회지
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• 제40권5호
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• pp.415-422
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• 2003

BaZr $O_3$를 기본으로 첨가제(Ce, Yb)를 넣어 B자리인 Zr을 부분적으로 치환하였고 Ce의 첨가량을 달리하여 4가지의 조성을 갖는 시편을 제조하였다. 제조된 시편을 임피던스 분석 장치를 이용하여 건조공기 분위기와 수증기 분위기에서 전기적 특성을 측정하였다. $600^{\circ}C$ 이하의 낮은 온도 영역에서, 수증기 분위기에서의 전기전도도가 건조공기 분위기에서의 전기전도도 보다 모든 조성에서 높은 값을 나타냈고 Ce의 첨가량이 증가할수록 높은 전도도 값을 보였다. BaZ $r_{0.8}$C $e_{0.15}$Y $b_{0.05}$ $O_3$$_{-{\delta}}$조성을 갖는 시편이 80$0^{\circ}C$에서 가장 높은 1.72$\times$$10^{-3}$ S$cm^{-1}$ / 전기전도도 값을 나타냈다. 낮은 온도영역에서는 수소이온 전도에 의해 건조공기 분위기 보다 수증기 분위기에서 높은 전지전도도를 나타냈지만 온도가 올라갈수록 수소이온 전도도가 줄어들면서 $700^{\circ}C$ 근처에서는 거의 비슷한 값을 보였다.

• 한국광물학회지
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• 제16권4호
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• pp.307-320
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• 2003

Fe­석류석인 경우, 사면체 배위를 하는 Fe의 이온반경이 Si보다 크기 때문에 고준위 방사성 폐기물에 다량 함유되어 있는 악티나이드 원소들을 고정화시킬 수 있는 매트릭스로 고려되고 있다. 따라서 본 연구에서는 $Ca_{2,5}$C $e_{0.5}$Z $r_2$F $e_3$ $O_{12}$ 및 $Ca_2$CeZrFeF $e_3$ $O_{12}$인 조성을 가진 석류석을 합성하여 이들의 상평형 관계 및 특성을 연구하였다. 혼합된 시료는 200∼400 kg/$\textrm{cm}^2$의 압력으로 성형한 후, 1100∼140$0^{\circ}C$ 범위에서 온도 및 분위기를 변화시키면서 소결하였으며 합성된 시료는 XRD, SEM/EDS를 사용하여 상분석과 정량분석을 실시하였다. 실험결과, 이들 조성을 가진 석류석들은 130$0^{\circ}C$로 가열하였을 때, 최적 합성상을 얻을 수 있었지만 소량의 페롭스카이트 등 부수상이 공존하였다. $Ca_{2,5}$C $e_{0.5}$Z $r_2$F $e_3$ $O_{12}$ 및 $Ca_2$CeZrFeF $e_3$ $O_{12}$인 조성으로부터 합성된 Fe­석류석의 조성이 각각 $Ca_{2.5­3.2}$C $e_{0.3­0.7}$Z $r_{1.8­2.8}$F $e_{1.9­3.2}$ $O_{12}$ 및 $Ca_{2.2­2.5}$C $e_{0.8­1.0}$Z $r_{1.3­1.6}$F $e_{0.4­.07}$ F $e_{3­3.2}$ $O_{12}$였다. 특히 화학양론적 조성과 비교시, 합성된 석류석의 8배위 자리를 점하고 있는 Ca이 초과된 양상을 보였고, Ce의 함량은 초과 또는 결핍된 양상을 보였다. 이는 8배위 자리에서의 Ca과 Ce의 이온반경의 상대적인 차이 및 전하보상적 차원에서 비롯된 것으로 해석된다.에서 비롯된 것으로 해석된다.

• 한국재료학회지
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• 제13권8호
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• pp.543-549
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• 2003

In order to investigate the thermoelectric properties of $Zn_{k}$ $In_2$$O_{ 3＋k}$ homologous compounds, the samples of $Zn_{k}$ /$In_2$$O_{3＋k}$ / (k = integer between 1 and 9) were prepared by calcining the mixed powders of ZnO and $In_2$$O_3$fellowed by sintering at 1823 K for 2 hours in air, and their electrical conductivities and Seebeck coefficients were measured as a function of temperature in the range of 500 K to 1150 K. X-ray diffraction analysis of the sintered samples clarified that single-phase specimens were obtained for $Zn_{k} /$In_2$$O_{3＋k}$ with k = 3, 4, 5, 7, 8, 9. Electrical conductivity of the $Zn_{k}$ $In_2$$O_{3＋k}$ / decreased with increasing temperature, and decreased with increasing k for k $\geq$ 3. The Seebeck coefficient was negative at all the temperatures for all compositions, confirming that $Zn_{k}$ $In_2$$O_{3＋k}$ / is an n-type semiconductor. Absolute values of the Seebeck coefficient increased linearly with increasing temperature and increased with increasing k for k $\geq$ 3. The temperature dependence of the Seebeck coefficient indicated that Z $n_{k}$I $n_2$ $O_{3＋k}$ could be treated as an extrinsic degenerate semiconductor. Figure-of-merits of Z $n_{k}$I $n_2$ $O_{3＋k}$ were evaluated from the measured electrical conductivity and Seebeck coefficient, and the reported thermal conductivity. Z $n_{7}$ I $n_2$ $O_{10}$ has the largest figure-of-merit over all the temperatures, and its highest value was $1.5{\times}$10$^{-4}$ $K^{-1}$ at 1145 K.5 K.