• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.35.3-36
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• 2009

To investigate properties of the stellar contents of the resolved asymptotic giant branch stars in the nearby dwarf galaxies, we obtained wide-field JHKs images of the dwarf irregular galaxies NGC 6822, IC 1613 and the dwarf elliptical galaxy NGC 205, using the WIRCam near-infrared imager of the CFHT. The obtained (J-Ks, Ks) and (H-Ks, Ks) color-magnitude diagrams for the resolved stars in the galaxies contain populations of foreground stars, super giant stars, red giant stars and the asymptotic giant branch (AGB) stars. Using corollary photometric data in the visible bands, AGB stars were selected in the color-magnitude diagrams with a wide wavelength baseline in color indices. In color-color diagrams of the resolved AGB stars, we identified C stars from M giant stars for each galaxies, i.e., 726 C stars in NGC 6822, 126 C stars in IC 1613 and 593 C stars in NGC 205. The number ratios of C stars to M-giants were estimated to be $0.59\pm0.03$ in NGC 6822, $0.30\pm0.03$ in IC 1613 and $0.14\pm0.01$ in NGC 205. From analyses of the correlations of the spatial distribution of the C/M ratios with the HI properties and dynamical structures of the target galaxies, we discuss environmental effects of the star formation in the galaxies. We also discuss the epochs of the AGB star formation in the galaxies by comparing theoretical isochrones with the color distributions and luminosity functions of the AGB stars.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1591-1598
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• 2011

The objective of this paper is to study how to apply the functional models in the design reviews and the validation of the subsequent design specifications and standards in the urban rail transit standardization program. The functional models can be obtained based on the requirements. Specifically, the requirements are first represented by the use case and sequence diagrams and then the results are transformed into the functional models using the Systems Modeling Language (SysML) diagrams and the FFBD (Functional Flow Block Diagram) and others. Based on the results of the study, it can be checked whether the original requirements have been reflected properly in the designs. Also, it can be seen that how the possible changes in the requirements affect the functions and thus how the designs should be changed accordingly.

• Journal of Mechanical Science and Technology
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• 제15권2호
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• pp.210-216
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• 2001

This paper presents an analytical study that can predict the path-dependent forming limit of anisotropic sheet materials that experience various combinations of strain paths. To predict the forming limit diagrams(FLD), the proposed analytical procedure is performed within the framework of the Marciniak and Kuczynski(M-K) approach by using the Barlat and Lians non-quadratic anisotropic yield criterion and introducing the effect of the existence of a strain gradient over a stretching punch. The predicted path-dependent forming limit of an anisotropic sheet has been compared with the published experimental results. It has been found that the predicted path-dependent forming limits are in good agreement with the experimental data.

• 한국철도학회논문집
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• 제8권5호
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• pp.434-438
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• 2005

In this paper, as the first step to assess and enhance the reliability of Korea High Speed Train, an electric traction system is selected and reliability analysis is carried out. The electric traction system is classified into subsystems and functional block diagrams and reliability block diagrams are drawn. Expressions for evaluating the reliability are derived and Mean Kilometer Between Service Failure is calculated using the trial track test results. The calculation results show reliability growth of the proposed system.

• 천문학회보
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• 제35권2호
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• pp.80.1-80.1
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• 2010

From the Akari observational data, we have cross-identified a major portion of AGB stars listed in the catalog of AGB stars presented by Suh & Kwon (2009). We have used the Akari-IRC (Infrared Camera) PSC (Point Source Catalogue; about 850,000 sources at 9 and $18\;{\mu}m$) and Akari-FIS (Far-infrared Surveyer) BSC (Bright Source Catalogue; about 440,000 sources at 65, 90, 140 and $160\;{\mu}m$) as well as the IRAS and NIR observational data to make various meaningful two-color diagrams for AGB stars. We compare them with the theoretical models with various dust shell model parameters and chemical compositions.

• 한국시스템다이내믹스연구
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• 제11권1호
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• pp.85-102
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• 2010

This paper explores the ways in which the functions of local educational authority in Korea can be analyzed by systems thinking, and puts forward some policy leverage strategies to enhance predictability of education policy effects and also to prevent unanticipated side effects arising from it. In dong so, we sketch causal diagrams to depict functional changes of local educational authority, based on before and after comparison, and attempt to derive policy intervention points to minimize unforseen reactions from the stake-holders concerned. These diagrams make it possible for educational policy-makers to capture the feedback, stocks and flows, time delays, and non-linearities they identify, although they have some limitations. This paper concludes that newly-designed functions and structures for local educational authority may be accepted by the stake-holders including teachers and unions, only if complex systems surrounding functional changes regarding local educational authority can be clearly understood and relevant policy measures can be effectively taken before the functional changes happen.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.861-864
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• 2008

This study was performanced to investigate the fractural and fatigue behavior of ultra-strength steel fiber reinforcement concrete. The tension softening diagram can describe the post-cracking behavior of concrete in tension. In this paper, Three points bending tests with a notch have been carried out to investigate tensile properties of the steel fiber reinforced concrete(SFRC) according to variation of the height. Poly-linear approximation method combined with FEM analysis is applied to the steel fiber reinforced concrete to determine the tension softening diagrams and also to certify the validity of the method. The simulated load-CMOD curves using the determined softening diagrams though the poly-linear approximation method completely agree with the measured ones.

• 천문학회보
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• 제36권1호
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• pp.84.1-84.1
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• 2011

We observed several young stellar objects (YSOs) using the Photodetector Array Camera and Spectrometer (PACS) aboard the Herschel Space Observatory. CO, OH, $H_2O$, [O I], and [C II] lines were detected. CO rotational diagrams show two distinct gas components of ~400 K and ~1000 K with a break around 1500 K of the CO excitation energy, indicative of two different heating mechanisms: PDR and outflow shocks. OH and $H_2O$ line fluxes can be fitted with temperatures different from what are derived from the CO rotational diagrams. In order to understand the physical environment of line formation, the sources were modeled with the 3-D radiative transfer code, LIME. We present the results of observations, simple analysis, and modeling of Herschel-PACS spectra of the YSOs.

• 천문학회보
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• 제26권2호
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• pp.44-44
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• 2001

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 가을 학술발표논문집 Vol.34 No.2 (A)
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• pp.46-47
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• 2007