• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.70.4-70.4
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• 2015

Although the theory of stellar structure and evolution is considered one of the most successful developments in astrophysics, there still remains a significant mismatch between theoretical stellar models and the observed main sequence of the best studied nearby open clusters. To ease the tension, empirical corrections to the color-temperature transformations are used as a simple, but practical way of overcoming the difficulty than directly examining stellar atmosphere models that have large theoretical complexities and uncertainties. I will describe our continuing effort to calibrate stellar isochrones using cool main-sequence stars in Praesepe, complementing our previous work based on the Hyades and the Pleiades, and provide an extensive test of our models using photometry of cool and metal-rich main-sequence stars in NGC 6791. Finally, I will discuss the implication of our results on the mass loss in NGC 6791.

• Journal of Astronomy and Space Sciences
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• v.24 no.1
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• pp.1-30
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• 2007

We present the Pre-Main Sequence (PMS) evolutionary tracks of stars with $0.065{\sim}5.0M_{\odot}$. The models were evolved from the PMS stellar birthline to the onset of hydrogen burning in the core. The convective turnover timescales which enables an observational test of theoretical model, particulary in the stellar dynamic activity, are also calculated. All models have Sun-like metal abundance, typically considered as the stars in the Galactic disk and the star formation region of Population I star. The convection phenomenon is treated by the usual mixing length approximation. All evolutionary tracks are available upon request.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.84-87
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• 1997

In this study, for the coding of stereoscopic video sequence, two approaches are presented based on simulcast mathod and sidefield image format. The field sequential method for stereoscopic visualization have been specified. Also, camera parameter and shooting conditions for each test sequence are studied. Coding method based on sidefield format structure revealed better performance over simulcast in PSNR.

• Proceedings of the KIEE Conference
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• summer
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• pp.619-621
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• 2004

This paper presents the rapid and accurate algorithm for fault discrimination in transmission lines. When faults occur in transmission lines, fault discrimination is very important. If high impedance faults occur in transmission lines, it cannot be detected by overcurrent relays. The method using current and voltage cannot discriminate high impedance fault. Because of this reason this paper uses voltage and zero sequence current, and the proposed algorithm uses fuzzy logic method. This algorithm uses voltage and zero sequence current per period in case of faults. Single line ground fault and three-phase fault can be detective using voltage. Two-line ground fault and line to line fault and high impedance can be detected using zero sequence current. To prove the performance of the algorithm, it test algorithm with signal obtained from ATPDraw simulation.

• Journal of applied mathematics & informatics
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• v.12 no.1_2
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• pp.155-164
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• 2003

A method is proposed to predict the distances between given residue pairs (between C$\sub$${\alpha}$/ atoms) of a protein using a sequence to structure mapping by indefinite quadratic approximation. The prediction technique requires a data fitting in three dimensional space with coordinates of the residues of known structured proteins and leads to a numerical ref resentation of 20 amino acids by minimizing a large least norm iteratively. These approximations are used in distance prediction for given residue pairs. Some computational experience on a test set of small proteins from Brookhaven Protein Data Bank are given.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.63-71
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• 2006

In this paper, we consider a planning problem arising from printed circuit board manufacturing industries. Given a set of several types of PCBs, component feeders and surface mounting machines in series in a PCB assembly line, the problem is to define the feeder allocation and job sequence with the objective of minimizing the total operation time of the line. We formulate the problem as a mathematical model. And, the problem is proven to be NP-hard, so a genetic algorithm is developed. Finally, we give test results to evaluate the performance of the genetic algorithm.

• Annual Conference on Human and Language Technology
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• 2016.10a
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• pp.56-61
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• 2016

본 논문에서는 Sequence-to-sequence 모델을 생성요약의 방법으로 한국어 문서요약에 적용하였으며, copy mechanism과 input feeding을 적용한 RNN search 모델을 사용하여 시스템의 성능을 높였다. 인터넷 신문기사를 수집하여 구축한 한국어 문서요약 데이터 셋(train set 30291 문서, development set 3786 문서, test set 3705문서)으로 실험한 결과, input feeding과 copy mechanism을 포함한 모델이 형태소 기준으로 ROUGE-1 35.92, ROUGE-2 15.37, ROUGE-L 29.45로 가장 높은 성능을 보였다.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.177-178
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• 2015

This paper presents a neutral point deviation compensating control algorithm applied to a 3-level NPC converter. The neutral point deviation is analyzed with a focus on the current flowing out of or into the neutral point of the dc link. Based on the zero sequence components of the reference voltages, this paper analyzes the neutral point deviation and balancing control for 3-level NPC converter. An analytical method is proposed to calculate the injected zero sequence voltage for NP balancing based on average neutral current. This paper also proposes a control scheme compensating for the neutral point deviation under generalized unbalanced grid operating conditions. The positive and negative sequence components of the pole voltages and ac input currents are employed to accurately explain the behavior of 3-level NPC converter. Simulation and experimental results for a test set up of 30kW are shown to verify the validity of the proposed algorithm.

• Communications for Statistical Applications and Methods
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• v.3 no.2
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• pp.175-185
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• 1996

For the Change-point problem in a sequence of binomial variables we consider the maximum likelihood estimator (MLE) of unknown change-point. Its asymptotic distribution is quite limited in the case of binomial variables with different numver of trials at each time point. Hinkley and Hinkley (1970) gives an asymptotic distribution of the MLE for a sequence of Bernoulli random variables. To find the asymptotic distribution a numerical method such as bootstrap can be used. Another concern of our interest in the inference on the change-point and we derive confidence sets based on the liklihood ratio test(LRT). We find approximate confidence sets from the bootstrap distribution and compare the two results through an example.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.2024-2027
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• 2005

This study was aimed to prove the safety of rubber-tired AGT light rail vehicle, which was designed to have the redundant equipment for safety, so the experiment of this paper was operated in condition of malfunction which we made such as bake sequence test and momentary interruption test. The result can bes handled by Labview 7.0 and showed as the graph.