• 천문학회보
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• 제38권1호
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• pp.59.2-59.2
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• 2013

Wilson and Bappu found a tight correlation between the stellar absolute visual magnitude (MV) and the width of the Ca II K emission line for late-type stars in 1957. Here, we revisit the Wilson-Bappu relationship (hereafter, WBR) to claim that WBR can be an excellent indicator of stellar surface gravity of late-type stars as well as a distance indicator. We have measured the width (W) of the Ca II K emission line in high resolution spectra of 125 late-type stars, which were obtained with Bohyunsan Optical Echelle Spectrograph (BOES) and adopted from the UVES archive. Based on our measurement of the emission line width (W), we have obtained a WBR of $M_V=33.76-18.00{\log}W$. In order to extend the WBR to be a surface gravity indicator, the stellar atmospheric parameters such as effective temperature ($T_{eff}$), surface gravity (logg), metallicity ([Fe/H]), and micro-turbulence (${\xi}_{tur}$) have been derived from the self-consistent detailed analysis using the Kurucz stellar atmospheric model and the abundance analysis code, MOOG. Using these stellar parameters and logW, we found that ${\log}g=-5.85\;{\log}W+9.97\;{\log}T_{eff}-23.48$ for late-type stars.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제6권1호
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• pp.33-38
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• 2006

In this paper, we propose a new architecture of Fuzzy Polynomial Neural Networks(FPNN) by means of genetically optimized Fuzzy Polynomial Neuron(FPN) and discuss its comprehensive design methodology involving mechanisms of genetic optimization, especially Genetic Algorithms(GAs). The conventional FPNN developed so far are based on mechanisms of self-organization and evolutionary optimization. The design of the network exploits the extended Group Method of Data Handling(GMDH) with some essential parameters of the network being provided by the designer and kept fixed throughout the overall development process. This restriction may hamper a possibility of producing an optimal architecture of the model. The proposed FPNN gives rise to a structurally optimized network and comes with a substantial level of flexibility in comparison to the one we encounter in conventional FPNNs. It is shown that the proposed advanced genetic algorithms based Fuzzy Polynomial Neural Networks is more useful and effective than the existing models for nonlinear process. We experimented with Medical Imaging System(MIS) dataset to evaluate the performance of the proposed model.

• 천문학회보
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• 제41권1호
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• pp.45.3-46
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• 2016

Solar activity shows a self-similarity as it has many periods of activity cycle in the time series of long-term observation, such as 13.5, 51, 150, 300 days, and 11, 88 years and so on. Since fractal dimension is a quantitative parameter for this kind of an irregular time series, we applied this method to long-term observations including sunspot number, total solar irradiance, and 3.75 GHz solar radio flux to predict the start and maximum times as well as expected maximum sunspot number for the next solar cycle. As a result, we found that the radio flux data tend to have lower fractal dimensions than the sunspot number data, which means that the radio emission from the sun is more regular than the solar activity expressed by sunspot number. Based on the relation between radio flux of 3.75 GHz and sunspot number, we could calculate the expected maximum sunspot number of solar cycle 24 as 156, while the observed value is 146. For the maximum time, estimated mean values from 7 different observations are January 2013 and this is quite different to observed value of February 2014. We speculate this is from extraordinary extended properties of solar cycle 24. As the cycle length of solar cycle 24, 10.1 to 12.8 years are expected, and the mean value is 11.0. This implies that the next solar cycle will be started at December 2019.

• 전자공학회논문지A
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• 제31A권8호
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• pp.91-99
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• 1994

Damage induced by Si ion implantation and its annealing behavior during rapid thermal annealing were investigated by cross-sectional TEM (transmission electron microscopy) and RB ( Rutherford backscattering) spectrum. 150keV and 50keV Si ions were implanted in Si (100) at room temperature with doses of 2${\times}10^{15}cm^{-2}$. And 100keV Si ions were implanted in Si with doses from 1${\times}10^{14}cm^{-2}$. A variety of damage structures were generated by Si ion implantation such as continuous amorphous layer extending to the surface buried amorphous layer and damage clusters. Damage clusters are annealed out at the lower annealing temperature of 550 $^{\circ}C$. However, event at the temperature of 110$0^{\circ}C$ end of range loops remain in the original lower amorphous/crystal interface in the case of continuous and buried amorphous layer formation. Extended defects in the shape of zipper dislocations are also observed at the middle of the recrystallized region in the buried amorphous layer.

• 한국정보시스템학회지:정보시스템연구
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• 제15권4호
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• pp.171-188
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• 2006

Information technology and the Internet have had a dramatic effect on education method and individual life. Universities and companies we making large investments in e-Learning applications but are hard to pressed to evaluate the success of their e-Learning systems. e-Learning can be seen as not only one of Internet based information systems which can provide education services but also one of teaching-teaming methods which can implement self-directed teaming. This paper tests the updated model of information system success proposed by Delone and McLean using a field study of a e-Learning. The five dimensions - information quality, system quality, service quality, user satisfaction, net benefit - of the updated model are parsimonious framework for organizing the e-learning success metrics identified in the literature. Questionaires are collected from 107 students who are enrolling a e-learning class using online survey. The model is tested using SPSS and LISREL. The results show that information quality and service quality are significant predictors of user satisfaction with the e-Learning system but system quality is not. Also user satisfaction is found to be a strong predictor of the learning performance. This strong association between user satisfaction and teaming performance suggests that user satisfaction may serve as a valid surrogate for teaming performance. Empirical testing of the updated DeLone & McLean model should therefore be extended to cover a wider variety of systems.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3703-3706
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• 2010

Biomolecules specific to explosives can be exploited as chemical sensors. Peptides specific to immobilized dinitrotoluene (DNT) were identified using a phage display library. A derivative of DNT that contained an extended amine group, 4-(2,4-dinitrophenyl)butan-1-amine, was synthesized and immobilized using a self-assembled monolayer surface on gold. Filamentous M13 phages displaying random sequences of 12-mer peptides specific to the immobilized DNT-derivate were isolated from the M13 phage library by biopanning. A common peptide sequence was identified from the isolated phages and the synthesized peptides showed selective binding to DNT. When the peptide was immobilized on a quartz crystal microbalance (QCM) chip, it showed a binding signal to DNT, while toluene barely showed significant binding to the QCM chip. These results demonstrate that peptides screened by biopanning against immobilized DNT can be useful for quick and accurate detection of DNT.

• 천문학회지
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• 제28권2호
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• pp.255-264
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• 1995

The HII region S140 and the associated molecular cloud L1204 have been observed with 10 molecular transitions, CO (1-0), $^{13}CO$ (1-0), $C^{18}O$ (1-0), CS (2-1), $HCO^+$ (1-0), HCN (1-0), SO (${2_2}-{1_1}$), $SO_2(2_{20}-3_{13})$, OCS (8-7), and $HNCO\;(4_{04}-3_{03})$ with ${\sim}50"$ angular resolutions. More than 7,000 spectra were obtained in total. The morphology of this region shows a massive fragment (the S140 core) and the extended envelope to the northeast. Several gas condensations have been identified in the envelope, having masses of ${\sim}10^{3}M_{\odot}$ and gas number densities of ${\lesssim}10^{4}cm^{-3}$ to $3{\times}10^{5}cm^{-3}$ in their cores. The column densities of the observed molecular species toward the S140 core appear to be the typical warm clouds' abundances. It seems to be that the S140 core and L1204 have been swept up by an expanding shell called the Cepheus bubble. The large value of $L_{IR}$(embedded\;stars)/$M_{cloud}\;{\sim}\;5\;L_{\odot}$/$M_{\odot}$ of the S140 core may suggest that the star formation has been stimulated by the HII region, but the shock velocity and the pressure of the region seem to give a hint of the spontaneous star formation by the self gravity.

• Applied Science and Convergence Technology
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• 제23권2호
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• pp.72-82
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• 2014

Lithium-ion batteries (LIBs) have become popular electrochemical devices. Due to the unique advantages of LIBs in terms of high operating voltage, high energy density, low self-discharge, and absence of memory effects, their application range, which was primarily restricted to portable electronic devices, is now being extended to high-power applications, such as electric vehicles (EVs) and hybrid electrical vehicles (HEVs). Among various anode materials, $Li_4Ti_5O_{12}$ (LTO) is believed to be a promising anode material for high-power LIBs due to its advantages of high working potential and outstanding cyclic stability. However, the rate performance of LTO is limited by its intrinsically low electronic conductivity and poor $Li^+$ ion diffusion coefficient. This review highlights the recent progress in improving the rate performance of LTO through doping, compositing, and nanostructuring strategies.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 추계학술발표논문집 (상)
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• pp.205-208
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• 2002

본 논문에서는 기존의 그리드 컴퓨팅을 위한 미들웨어인 Globus의 정보 서비스 시스템인 MDS의 확장된 정보시스템 설계를 기술한다. 제안된 시스템은 자원 접근 및 발견을 위해 P2P 기반의 결함 포용을 갖는 강건하고 적응형 정보 서비스를 제공한다. MDS 는 가상 조직(Virtual Organization, VO) 으로 이루어진 네트워크 상에 자원의 위치 및 상태 정보를 제공하는 디렉토리 서비스이다. 그러나 현재 MDS 시스템은 결함의 기점(Single-point failure) 및 중복으로 등록된 자원에 대한 추가적인 트래픽을 발생시킨다. P2P 기반 정보 서비스 시스템은 기존의 클라이언트/서버 기반의 정보 서비스에 비해 정보의 가용성이 높고 수동적인 정보 서비스 수행 객체인 VO의 자치성을 보장함으로써 그리드 컴퓨팅 자원에 대한 유효한 실시간 접근을 제공한다. 또한 그리드 컴퓨팅의 확장으로 그리드 컴퓨팅에 참여하는 자원의 수가 증가함에 따라 정보 서비스 시스템의 확장성 및 정보 서비스의 개체인 VO간의 자기 조직화(self-organization)를 지원한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2627-2629
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• 2003

In this paper, we propose a new architecture of Genetic Algorithms(GAs)-based Self-Organizing Polynomial Neural Networks(SOPNN). The conventional SOPNN is based on the extended Group Method of Data Handling(GMDH) method and utilized the polynomial order (viz. linear, quadratic, and modified quadratic) as well as the number of node inputs fixed (selected in advance by designer) at Polynomial Neurons (or nodes) located in each layer through a growth process of the network. Moreover it does not guarantee that the SOPNN generated through learning has the optimal network architecture. But the proposed GA-based SOPNN enable the architecture to be a structurally more optimized networks, and to be much more flexible and preferable neural network than the conventional SOPNN. An aggregate performance index with a weighting factor is proposed in order to achieve a sound balance between approximation and generalization (predictive) abilities of the model. To evaluate the performance of the GA-based SOPNN, the model is experimented with using nonlinear system data.