• Journal of The Korean Astronomical Society
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• v.15 no.2
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• pp.49-58
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• 1982

The UBVRIHKL magnitudes on Johnson system and space motions of M dwarf stars have been collected. This sample of M stars have been distinguished on a purely kinematical basis; the one with e<0.15, young disk population, with 0.150.3 halo population. On the color-color diagrams and the color excess-orbital eccentricity diagrams, there is no distinction between the old disk stars and the young disk stars. However (I-H) color could be used to distinguish halo stars from young and old disk stars and the color excesses, ${\Delta}(U-B),\;{\Delta}(B-V),\;{\Delta}(V-R),\;{\Delta}(H-K),\;{\Delta}(K-L),\;and\;{\Delta}(B-R)$ can be used as abundance indicators only for the halo stars. But these color excesses which are measures of blue excesses, are positive for the halo stars with smaller eccentricities and become negative for those with larger eccentricities.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.5
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• pp.67-73
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• 2012

Failure mechanisms for a solid propellant were discussed, and the stip-yield and the inherent flaw models were applied to them. Then, failure assessment diagram methods were investigated by means of modified two models. Fracture toughness tests using CCT(center-cracked tension) specimens made of a solid propellant were conducted to generate the failure assessment diagrams. The failure assessment diagram of the inherent flaw model was normalized in order to compare with that of the modified strip-yield model. From the comparison of two failure assessment diagrams, it was found that the failure assessment diagram of the modified inherent flaw model more conservatively assesses the failure than that of the modified strip-yield model.

• Journal of the Korean Society of Systems Engineering
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• v.13 no.2
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• pp.42-48
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• 2017

OCD (Operational Concept Document) is very important in system development. To develop OCD we should answer questions about, what template to use, what is the overall process to develop OCD, what kinds of diagrams we should use and how can we validate the OCD. To answer about the template we compared tow industrial guide on operational concept development and tailored it. For development process, we proposed a comprehensive process which satisfies the requirements of the project context. For use of proper diagram, we analyzed many kinds of diagrams used in representing behavior of system and choose some diagrams which best fit for our purpose. Finally we established validation criteria for operational scenario and requirement texts in operational concept documents.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.54.2-54.2
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• 2010

The most massive galactic globular cluster, $\omega$ Cen has been observed using recently mounted WFC3/UVIS cameras of Hubble Space Telescope at both near-UV and optical bands. We present the photometry of stars in the central region of $\omega$ Cen in F225W, F275W and F336W bands. The near-UV color-magnitude diagrams and color-color diagrams of stars in $\omega$ Cen show multiple red giant branches and main sequences as already discovered in both ground-based and HST/ACS observations in the optical bands. We modelled the stellar populations of $\omega$ Cen using Yonsei Isochrone, where $\alpha$-particles and helium enhancement processes have been included properly. We compare the best-fit stellar populations obtained from the current near-UV observations to the suggested stellar population models based on optical band data. We also discuss the methodological issues arising when dealing with the near-UV observations; red-leak in near-UV filters and the huge interstellar extinction in near-UV bands compared to the optical bands and its non-linear effect in color-magnitude diagrams.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.532-538
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• 2012

Failure mechanisms for a highly filled elastomer were discussed, and the stip-yield and the inherent flaw models were applied to them. Then, failure assessment diagram methods were investigated by means of modified two models. Fracture toughness tests using CCT(center-cracked tension) specimens made of a highly filled elastomer were conducted to generate the failure assessment diagrams. The failure assessment diagram of the inherent flaw model was normalized in order to compare with that of the modified strip-yield model. From the comparison of two failure assessment diagrams, it was found that the failure assessment diagram of the modified inherent flaw model more conservatively assesses the failure than that of the modified strip-yield model.

• Korean Journal of Human Ecology
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• v.20 no.1
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• pp.205-223
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• 2011

This study examines diagrams of space organization and classroom activity zoning through Korean Childcare Accreditation Criteria, and compares space diagrams with childcare facilities in Daejeon, and looks at similarities and differences between them. Space diagram from accreditation criteria show the classroom, adjoining toilets, napping areas, and community areas for playing, reading, cooking, teaching and holding materials. Classroom zone diagrams show 8 activity zones for entering, washing and toilet, making art, playing, reading, studying science, resting, playing role and wooden block. Six case studies in Daejeon, Korea were surveyed and classified into big, medium and small size facilities by the number of children. The space organization of case studies are similar to the diagrams, except that outdoor playground and indoor playrooms were not large enough at the small and medium size facilities. Classroom activity zoning was very similar to the conceptions, excluding the playarea from classroom, integrating the rest areas for reading, subdividing art into music and art, science, and into math and science, roleplay into roleplay and wooden block. In conclusion childcare centers in Daejeon are designed to the concept diagram of the accreditation criteria, with some flexibility, exclusion, integration, and subdivision of space and activity zones. It has been requested as to make each criteria fit to the facility sizes-big, medium and small.

• Archives of design research
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• v.19 no.5 s.67
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• pp.75-84
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• 2006

The aims of this study are to examine the conceptual contents of space diagram, and to find its elements and practical applications by analyzing the UN Studio. The Findings of this study are as follows: firstly, the conceptual contents represented in space diagram are classified into four elements - motif, flow, relationship, and distribution. Secondly, space diagram is used in program development, schematic design, and preliminary design of design process phases. Thirdly, the elements based on the case diagrams include five elements: context analysis, object analysis, time-behavior analysis, modeling analysis, and space analysis. Fourthly, in practical use, diagrams with motif concept is usually used in modeling analysis, and diagram with flow concept is commonly used in the analysis of time-behavior and object. Diagrams with relationship concept is mostly used in space analysis, secondly in analysis of context and modeling. Further, diagrams with distribution concept is usually used in space analysis. If one uses these findings for design projects in practical business or education, it would be helpful in design conception and development as well as of design information structuralization.

• Korean Institute of Interior Design Journal
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• v.17 no.6
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• pp.71-81
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• 2008

The purposes of this research are to correctly understand the relationship between a visual communication structure and a semantic communication structure when integrating and changing various architectural visual information. This study will classify various diagrams, which have been actively applied to the works of Rem Koolhaas and MVRDV when designing architecture, and based on the classification, it will analyze how the expression viewpoints inherent in the diagrams are changed and applied to processing and changing architectural visual information. The transformal usage of the visual information of architectural diagrams is classified into an analysis-centered processing method and a concept-centered processing method, and the characteristics of their usage are analyzed. The former shows an observer-centered expression viewpoint which effectively delivers an architect's analyzed architectural information or intent to a customer or an observer. It also allows an easy perception of the analyzed data, and uses qualitative expression viewpoints. The method combines systematic expression viewpoints, which value a relationship with visual information, and various architectural visual information; uses the combined expression viewpoints as one diagram for delivering various information simultaneously and for changing visual information. The latter shows author-centered subjective expression viewpoints, which are different from reproduction-centered fixed expression viewpoints. This method uses arbitrary expression viewpoints that overly extort, change or manipulate visual information. It shows simultaneous expression viewpoints that integrate various architectural visual information via omniscient expression viewpoints, such as reversing or projecting the points of viewing subjects, which human beings cannot perceive.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.72.2-72.2
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• 2013

We present a UBVI and $H{\alpha}$ photometric study of the young open cluster NGC 1893 in the outer Galaxy as part of "Sejong Open cluster Survey (SOS)" project. Using the properties of early-type stars in the photometric diagrams 65 early-type members were selected. More than 120 $H{\alpha}$ emission stars and candidates were found by $H{\alpha}$ photometry. Together with the published young stellar object catalogue and X-ray source list for this cluster, a total of 837 pre-main sequence (PMS) stars were identified in our photometric data. We obtained the mean reddening of < E(B-V) > = $0.56{\pm}0.08$ mag from the (U-B, B-V) diagram and confirmed the normal reddening law ($R_V=3.1$) toward NGC 1893 based on color excess ratios from optical to mid-infrared wavelengths. The zero-age main sequence fitting to the reddening-corrected color-magnitude diagrams gives a distance modulus of $V_0-M_V=12.8{\pm}0.1$. The age of the cluster inferred from stellar evolution models is about 1-2 Myr. We also found the Salpeter/Kroupa type initial mass function for this cluster. Finally, the mass accretion rate of 80 PMS stars with UV excess emission was estimated for the stars with masses from $0.6M_{\odot}$ to $5M_{\odot}$.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.95-105
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• 2004

The fundamental diagram is a important element in a variety of transportation studies. While various shapes of the fundamental diagram have been proposed and numerous debates on the best-fit fundamental diagram have been made, the reason why the fundamental diagram has many different shapes has not been well explained. This study introduces time sap as a key parameter to understand drivers' behavioral differences at different locations and traffic conditions, then relate to the shape of the fundamental diagram. From the freeway event detector data, it is shown that time gap follows a certain probabilistic distribution and its mean value varies along locations. It also turns out that drivers take different time gaps for different travel speeds. Three different types of time gap-speed diagrams are identified and matched to Greenberg, reversed-lambda, and inverted-V types of fundamental diagrams, respectively. This study explains the characteristics of fundamental diagrams using time gap as a microscopic variable and describes drivers' behavioral characteristics according to traffic and geometric conditions.