• 대한화학회지
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• 제50권5호
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• pp.385-393
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• 2006

연구에서는 고등학교 화학 수업에서 개방적 가설검증 학습모형을 적용한 과학 탐구학습을 실시하고, 학생들의 인지 수준에 따른 과학 탐구능력, 과학 수업에 대한 태도에 미치는 효과와 수업에 대한 인식을 알아보았다. 서울에 소재한 남자 고등학교 2학년 4개 학급의 학생들(92명)을 대상으로 개방적 가설검증 학습모형을 적용한 과학 탐구학습을 실시한 처치집단과 실험과정이 모두 제시된 실험 수업을 실시한 통제집단으로 배치한 후, 화학의 ‘금속과 그 이용' 단원에 대해서 수업을 실시하였다. 연구 결과에 의하면, 개방적 가설검증 학습모형을 적용한 과학 탐구학습은 과학 탐구능력 향상에 관해서 실험설계, 자료 변환 및 해석, 가설검증의 영역에서 유의미한 효과가 있었으며 문제 파악 및 정의, 가설설정의 영역에서는 효과가 없었다. 한편, 개방적 과학 탐구학습에서 학생들의 역할 및 수행할 과제의 증가로 인해 과학 수업에 대한 태도는 처치집단에 부정적인 효과가 나타났다.

• Journal of Chest Surgery
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• 제22권5호
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• pp.713-723
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• 1989

In order to assess the correlation of the myocardial damage and the duration of cardiopulmonary bypass, measurement of creatine kinase [CK], lactate dehydrogenase [LDH], asparatate aminotransferase [AST], and MB band of CK [CK-MB] were carried out on the first, third, fifth, seventh, and ninth day in 44 patients following open heart surgery [POD 1,3,5,7,9]. And the patients were divided into three groups according to the duration of aortic cross clamp time [ACT]: Group I [ACT< 60 minutes. n=19], Group II [60 minutes < ACT< 90 minutes, n=7] and Group III[90 minutes > ACT, n=18]. 1. The leakage of CK in total patients increased to the highest level at POD 1, with rapid decrease and recovery at POD 7. The leakage of CK in Group III were greater than in Group I from POD 1 to POD 3 [P < 0.01]. The recovery time of CK level was shorter in Group I [POD 3] than in Group II and III [POD 7]. 2. The serum levels of LDH in total patients increased to the highest level at POD 1, with slow recovery until POD 9. The levels of LDH in Group III were higher than in Group I until POD 9 [P < 0.005]. The levels of LDH in Group I and II recovered but not in Group III. 3. The serum levels of AST in total patients increased to the highest level at POD 1, with rapid decrease and recovery at POD 7. The levels of AST in Group III were greater than in Group I from POD 1 to POD 5 [P < 0.05]. The recovery time of AST level was shorter in Group I and II [POD 5] than in Group III [POD 7]. 4. The positive cases for CK-MB in 36 patients were 22 [61.1 %] as a whole, 5[41.6%] in Group I, 4[57.1 %] in Group II, 13[76.4 %] in Group III at POD 1, and a case in each group at POD 3, and only a case in Group Ill at POD 5. It is concluded that the myocardial injury was closely related with the duration of cardiopulmonary bypass in open heart surgery.

• 천문학회지
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• 제35권2호
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• pp.87-95
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• 2002

We have conducted VI CCD photometry of the open cluster NGC 6819 in order to understand the effects of dynamical evolution in old open clusters. Our photometry covers 18' $\times$ 18' on the sky, centered on the cluster, which seems to cover the whole cluster field. Our photometry reaches down to V $\approx$ 20.5, which allows us to analyze the luminosity function and spatial distribution of stars brighter than Mv $\approx$ 8.5. There is a clear evidence for mass segregation in NGC 6819, i.e., the giants and upper main-sequence stars are concentrated in the inner regions, whereas the lower main-sequence stars distribute almost uniformly throughout the cluster. The luminosity function of the main-sequence stars of NGC 6819 is almost flat. The flat luminosity function indicates that a large number of low mass stars has escaped from the cluster unless its initial mass function is much different from the Salpeter type (${\phi}(m){\propto} m^{-(1+x)},x = 1.35$).

• 전기학회논문지
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• 제63권9호
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• pp.1317-1320
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• 2014

In case of using three-phase induction motor in three-phase power system, if he deficiency happens in phase among three-phase, the motor will drive in an open phase state. As to the motor, the continuing operation is possible then, but the phenomenon that the power supply stops happening by the result of the overload electricity order on the healthy phase of two phases with a damage and activating the circuit breaker. Consequently, in order to overcome this problem in treatise accordingly. I propose an uninterruptible power supply which is able to prevent that the over current on the health phase through the restoration that in case happening open phase on the power line when driving the motor. Also, it is possible to supply power consecutively without interruption of electric power and we proved the performance and reliability through an experiment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1028-1033
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• 2004

The open deck steel bridge is the most common type in railway bridges. Steel I-shaped girders are connected with sleepers directly without ballast and moving train loads are transmitted directly to the girder, so this bridge has weak characteristics on impact. Therefore, considerable accelerations can cause unsatisfactory dynamic behavior of the open deck steel bridge. Especially, Impact created at rail joints can increase the dynamic response of the bridge and this phenomenon would be injurious to passenger comfort. In the present study, dynamic behavior of the open deck steel bridge which has a rail joint is estimated through experimental studies and bridge-train interaction analysis considering surface irregularities by rail joints.

• 정보관리연구
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• 제39권1호
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• pp.221-237
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• 2008

CrossRef는 DOI 식별자 및 학술메타정보를 수집할 수 있는 다양한 쿼리(OpenAPI)를 제공하고 있으며, 이를 활용해 출판사 및 정보서비스 기관에서 다양한 서비스를 개발하도록 독려하고 있다. 본 연구에서는 CrossRef에서 제공하는 쿼리를 면밀히 분석하였으며, 다양한 방법으로 DOI를 자동수집 하는 API를 개발하였다. 또한 자체적으로 학술메타데이터를 보유한 기관이 개발된 API를 활용할 수 있는 방법을 제시하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권3호
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• pp.466-477
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• 2015

In this study, a numerical prediction method on manoeuvrability of Wind Turbine Installation Vessel (WTIV) is presented. Planar Motion Mechanism (PMM) captive test for the bare hull of WTIV is carried out in the model basin and compared with the numerical results using RANS simulation based on Open-source Field Operation And Manipulation (OpenFOAM) calculation to validate the developed method. The manoeuvrability of WTIV with skeg and/or without skeg is investigated using the numerical approach along with the captive model test. In the numerical calculations, the dynamic stability index which indicates the course keeping ability is evaluated and compared for three different hull configurations i.e. bare hull and other two hulls with center skeg and twin skeg. This paper proves that the numerical approach using RANS simulation can be readily applied to estimate the manoeuvrability of WTIV at the initial design stage.

• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1561-1571
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• 2010

We define and characterize a fuzzy pairwise strong pre-irresolute continuous mapping and a fuzzy pairwise strong pre-irresolute open mapping on a fuzzy bitopological space.

• 천문학회지
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• 제41권6호
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• pp.147-155
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• 2008

We present UBV I photometry of the old open cluster NGC 1193. Color-magnitude diagrams (CMDs) of this cluster show a well defined main sequence and a sparse red giant branch. For the inner region of r < 50", three blue straggler candidates are newly found in addition to the objects Kaluzny (1988) already found. The color-color diagrams show that the reddening value toward NGC 1193 is E(B - V ) = $0.19{\pm}0.04$. From the ultraviolet excess measurement, we derived the metallicity to be [Fe/H]= $-0.45{\pm}0.12$. A distance modulus of ${(m\;-\;M)}_0$ = $13.3{\pm}0.15$ is obtained from zero age main sequence fitting with the empirically calibrated Hyades isochrone of Pinsonneault et al. (2004). CMD comparison with the Padova isochrones by Bertelli et al. (1994) gives an age of log t = $9.7{\pm}0.1$.

• 천문학회지
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• 제43권5호
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• pp.141-152
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• 2010

UBV I CCD photometry is obtained for the open clusters NGC 4609 and Hogg 15 in Crux. For NGC 4609, CCD data are presented for the first time. From new photometry we derive the reddening, distance modulus and age of each cluster - NGC 4609 : E(B-V ) = $0.37{\pm}0.03$, $V_0-M_V=10.60{\pm}0.08$, log $\tau$= 7.7 $\pm$ 0.1; Hogg 15 : E(B - V ) = 1.13 $\pm$ 0.11, $V_0-M_V$ = 12.50 $\pm$ 0.15, log $\tau$ $\lesssim$ 6.6. The young age of Hogg 15 strongly implies that WR 47 is a member of the cluster. We also determine the mass function of these clusters and obtain a slope $\Gamma$ = -1.2 ($\pm$0.3) for NGC 4609 which is normal and a somewhat shallow slope (${\Gamma}=-0.95{\pm}0.5$) for Hogg 15.