• 한국사회복지학회:학술대회논문집
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• 2007.04a
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• pp.699-701
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• 2007

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.05a
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• pp.83-83
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• 1999

• KOREAN POULTRY JOURNAL
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• v.12 no.5 s.127
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• pp.55-58
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• 1980

• The Mathematical Education
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• v.28 no.1
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• pp.57-61
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• 1989

• 한국도로학회:학술대회논문집
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• 2000.11a
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• pp.89-93
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• 2000

• International Journal of Aeronautical and Space Sciences
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• v.13 no.4
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• pp.421-427
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• 2012

Solar Sail propulsion has been validated in space (IKAROS, 2010) and soon several more solar-sail propelled spacecraft will be flown. Using sunlight for spacecraft propulsion is not a new idea. First proposed by Frederick Tsander and Konstantin Tsiolkovsky in the 1920's, NASA's Echo 1 balloon, launched in 1960, was the first spacecraft for which the effects of solar photon pressure were measured. Solar sails reflect sunlight to achieve thrust, thus eliminating the need for costly and often very-heavy fuel. Such "propellantless" propulsion will enable whole new classes of space science and exploration missions previously not considered possible due to the propulsive-intense maneuvers and operations required.

• Animal Systematics, Evolution and Diversity
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• v.36 no.1
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• pp.17-24
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• 2020

Doryctinae is a large and heterogeneous group with more than 1,000 described. It is idiobiont ectoparasitoids on the larvae of wood-boring and xylophagous beetles. Some species attack larvae of wood boring lepidoptera. In the present study, fifteen species belonging to eight genera of the subfamily Doryctinae are recorded for the first time from Korea: Doryctes Haliday (2 species), Eodendrus Belokobylskij (1 species), Heterospilus Haliday (4 species), Monolexis Förster (1 species), Neurocrassus Snoflak (2 species), Rhoptrocentrus Marshall (1 species), Sonanus Belokobylskij et Konishi (1 species), Spathius Nees (3 speices). The genera Eodendrus Belokobylskij, Monolexis Förster, Rhoptrocentrus Marshall, Sonanus Belokobylskij et Konishi and fifteen species are reported for the first times from Korea. Diagnosis and host information are provided.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.89-98
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• 1999

In this paper we estimate the reliability of parallel system with two components. We assume that the strengths of these components follow bivariate exponential(BVE) models proposed by Marshall-Olkin(1967) Block-Basu(1974) Freund(1961) and Proschan-Sullo(1974) These two components are subjected to a normally distributed random stress which is independent of the strength of the components. If the strengths ($\textit{X}_1$, $\textit{X}_2$) are subjected to a stress($\textit{Y}$) then the system reliability ($\textit{R}$) is given by $\textit{R}=\textit{P}[\textit{Y} We present some numerical results and compare the bias and the mean square error of the maximum likelihood estimator and proposed estimators for a moderate sized samples when $(\textit{X}_1, \textit{X}_2)$ follow BVE of Marshall-Olkin.

• Journal of the Mineralogical Society of Korea
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• v.12 no.2
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• pp.77-90
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• 1999

Characteristics and variations of chemical compositions in Co-rich crusts occurred in the EEZ of the Republic of Marshall Islands were reviewed. Correlation coefficient analysis, hierarchical cluster analysis, and Q-mode factor analysis for 62 samples were done in this study. All data were selected and gathered from the open file report of the cooperative cruise done by United States Geological Survey with Scripps Institute of Oceanography, University of Hawaii or Korea Ocean Research Development Institute. The average of crust thickness. Co content, and Ni content of 62 samples from the 21 seamounts were 30mm, 0.58 wt% and 0.40%, respectively. The mineral phases and associated elements assigned by correlation coefficients, cluster analysis and Q-mode factor analysis are following four. 1) CFA: P, Ca, CO2, Y, Sr: 2) Mn-oxide mineral: As, Mn, Co, Na: 3) Al-silicate mineral: Pd,Si, Al, Cu, Fe: 4) PGE-bearing mineral: Rh, Pt, Ir.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.627-634
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• 1997

This is the Study on Application and Manufacture Technique of Cold-Mix, Cold-Laid type Asphalt Concrete using of Polymer modified asphalt the could be constructed easily and economically on damaged road repaireless for seasons. The modified materials for this study are SBS(Styrene-Butadiene-Styrene). SBR (Styrene-Butadiene-Rubber) and PUR(Polyurethane). The Marshall stability and the value of flow and resistance in water stability degree according to the alternation types and weight percent of modified materials were compared and evaluated on this study. The results of the study show that PUR modified asphalt have improvement of over 150% Marshall stability in AI MS-14 standard and they are evaluated to have the easiness of storage and better working efficiency compared with other types of modified asphalt compound.