• 동력기계공학회지
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• 제9권2호
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• pp.57-64
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• 2005

This paper is the study on dry sliding wear behavior of carbon fiber reinforced epoxy matrix composites against lay-up orientation. Tests were investigated on the effect of the lay-up orientation, fiber sliding direction, load and sliding velocity when circumstance keep continuously at $21^{\circ}C$, 60%RH. Pin-on-disk dry sliding wear tests for each experimental condition were carried out with a carbon fiber reinforced plastic pin on stainless steel disk in order to search the friction and wear characteristics. The wear rates and friction coefficients against the stainless steel counterpart were experimentally determined and the wear mechanisms were microscopically observed. The effect on friction and wear behavior are observed differently, according to various conditions. When sliding took place against counterpart, the highest wear resistance and the lowest friction coefficient were observed in the $[0]_{24s}$ lay-up orientation at anti-parallel direction.

• Journal of Applied Biological Chemistry
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• 제56권1호
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• pp.5-9
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• 2013

The nutritional composition of transgenic rice (Agb0101) with bar and modified cry1Ac1 genes grown with herbicides was compared with that of its non-transgenic counterpart. The analyzed components (proximates, amino acids, fatty acids, minerals, vitamins, trypsin inhibitors, and phytic acid) in the herbicide-treated Agb0101 brown rice were substantially equivalent to those of its non-transgenic counterpart.

• 보건행정학회지
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• 제29권4호
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• pp.469-481
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• 2019

Background: As South Korea is becoming an aged society very rapidly, the increase in osteoarthritis prevalence raises various public health issues in this country. This study aimed to explore the socio-demographic factors associated with osteoarthritis in the current Korean elderlies. Methods: Using the National Survey of Korean Elderly data (2014, 2017), we analyzed 20,326 elderlies (males, 8,248; females, 12,078) and conducted multivariate logistic regression analyses by sex. The dependent variable is whether a participant was diagnosed with osteoarthritis or not. Independent variables of interest is socio-demographic factors such as age, marital status, household type, residential area, household income, religion, the longest job, the number of close relatives, the number of close friends, and survey year. Control variables are various health behavioral factors and disease-related factors. Results: Prevalence of osteoarthritis was 19.2% in male elderlies and 47.0% in female elderlies. According to the results of the multivariate logistic regression adjusted for all studied control variables, the odds ratio (OR) for having osteoarthritis of under-elementary school graduates (their counterpart was college graduate group) was 1.81 (95% confidence interval [CI], 1.29-2.52) in males and 1.67 (95% CI, 1.12-2.47) in females. The OR of those having a job in agriculture & forestry fishery as their longest job (their counterpart was those who had never participated in labor force during their lifetime) was 5.07 (95% CI, 1.46-17.58) in males and 1.49 (95% CI, 1.27-1.74) in females. In males, the second-low quartile group in household yearly income (their counterpart was the highest quartile group) had the OR of 1.22 (95% CI, 0.98-1.53). In females, the OR of those having a religion of Buddhism (their counterpart was those having no religion) was 1.20 (95% CI, 1.07-1.35) and the OR of those who had no relatives (their counterpart was those having more than 3 close relatives) was 1.31 (95% CI, 1.10-1.56). Conclusion: This study found that in Korean elderlies, education, the longest job, household income, religion, and the number of close relatives are associated with their suffering from osteoarthritis. Further study and designing appropriate interventions are needed to alleviate current and future individual and socioeconomic burdens of osteoarthritis in an aged society like South Korea.

• Structural Engineering and Mechanics
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• 제7권2호
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• pp.181-202
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• 1999

Dynamic response of axisymmetric arbitrary laminated composite cylindrical shell of finite length, using three-dimensional elasticity equations are studied. The shell is simply supported at both ends. The highly coupled partial differential equations are reduced to ordinary differential equations (ODE) with variable coefficients by means of trigonometric function expansion in axial direction. For cylindrical shell under dynamic load, the resulting differential equations are solved by Galerkin finite element method, In this solution, the continuity conditions between any two layer is satisfied. It is found that the difference between elasticity solution (ES) and higher order shear deformation theory (HSD) become higher for a symmetric laminations than their unsymmetric counterpart. That is due to the effect of bending-streching coupling. It is also found that due to the discontinuity of inplane stresses at the interface of the laminate, the slope of transverse normal and shear stresses aren't continuous across the interface. For free vibration analysis, through dividing each layer into thin laminas, the variable coefficients in ODE become constants and the resulting equations can be solved exactly. It is shown that the natural frequency of symmetric angle-ply are generally higher than their antisymmetric counterpart. Also the results are in good agreement with similar results found in literatures.

• 대한치과교정학회지
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• 제34권1호
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• pp.93-107
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• 2004

Enlow의 구조적 대응체 분석법은 다수의 평균에 의한 정상치와 비교하는 분석법과는 달리 개개인에서 두 개안면의 구성양상이 발달되어온 해부학적, 발육학적 특징의 복합체를 설명하는 방법이다. 본 연구에서는 악교정 수술을 시행한 골격성 III급 부정교합 환자 80명(남자 40명, 여자 40명)을 대상으로 구조적 대응체 분석법을 이용하여 수술 전후를 비교하고, 정상교합자와 비교하여 다음과 같은 결과를 얻었다. 1. 수술에 의해서 주로 하악지 전후방 길이(B3)가 감소되어 상하악의 전후방적 부조화가 해소되었다. 2. 수술에 의해서 하악지의 배열(R3, R4)이 후방으로 재배열되었으며 교합평면(R5)은 후하방으로 회전되었다. 3. 수술후와 정상교합자의 비교결과 수술후에 골격성 III급 양상은 해소되었으나 두개저수준(R1, R2)에서는 차이를 보이고 있다. 4. 수술방법에 따른 비교결과 양악수술은 상악골의 길이(A4), 하악지의 배열(R3, R4), 교합평면의 각도(R5)에서 하악수술과 차이를 보였으나 두 그룹간의 차이는 크지 않았다. 한국인 골격성 III급 부정교합자의 특징을 살펴본 지난 연구에서 골격적 원인은 두개저의 후상방회전, 상악골의 후방위치, 하악지의 전방경사, 하악골체부의 길이증가였는데 본 연구 결과 실제 수술에서 개선되는 요소는 주로 하악지의 전후방 길이 감소, 상악골의 전진이기 때문에 상대적인 개선으로 골격성 III급 양상이 해소되었다고 볼 수 있다. 이러한 결과는 실제적인 수술부위가 상악골과 하악골의 일부에 국한되기 때문이다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2011년도 한국우주과학회보 제20권1호
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• pp.19.2-19.2
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• 2011

In 1861 Nam Byeong-Gil published a book called as "Seonggyeong" which contains a star catalogue (NBGC) with the positions, magnitudes, and star maps for 1449 stars. The NBGC lists only the traditional Chinese stars selected from "the sequel to the Qing Dynasty Star Catalogue and Star Map." To identify each star from the NBGC with modern counterpart, we correct the positions of the Hipparcos stars brighter than 6.5 mag for proper motion, then precess the coordinates to the epoch of the NBGC. For each star in the NBGC, we find the nearest counterpart in the Hipparcos Catalogue (HC). If a much brighter star is at a slightly larger angular distance, we select that star as the secure counterpart. As a result, 95.5% of the stars in the NBGC were identified. We find a very good overall agreement of our results with a previous analysis by Ahn et al. (1996, Journal of the Korean History of Science Society, vol. I). For securely identified stars, we analyse its accuracy on the basis of comparison with data from the HC. The correlation of the errors between right ascensions and declinations is significantly deviated from spherical distribution. The magnitudes recorded in the NBGC correlate well with modern values. The accuracy of position decreases slowly with magnitude. Right ascensions and declinations have error distributions with ${\sigma}$ = 2.0' for the former while the latter with ${\sigma}$ = 1.6', but with much more errors >5' than expected for a Gaussian distribution.

• 천문학논총
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• 제7권1호
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• pp.107-148
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• 1992

This paper presents a cosmological perturbation analysis in a Newtonian framework, using the Newtonian multi component version of the relativistic covariant equations. This work considers the fully nonlinear evolution of the perturbations, and is generalized to multicomponent systems and imperfect fluids. Known nonlinear solutions are presented in a general framework. Quasi-nonlinear analysis, considering both the compressible and rotational modes, is presented, including cases already known in the literature. The Fourier space representation of the conservation equations is also derived in a general context, with various decompositions of the velocity field. Commonly accepted cosmogonical frameworks are critically examined in the context of nonlinear evolution. This work may be regarded as the Newtonian counterpart of a recently presented general relativistic covariant formulation.

• Asian Journal of Atmospheric Environment
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• 제8권3호
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• pp.154-161
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• 2014

The present study was undertaken to evaluate the chemical characteristics of Asian dust (hereafter called "AD") particles with the aid of the most advanced micro-PIXE (Particle-induced X-ray emission) analytical technique. To this end, size-selected particles were sampled on a rural peninsula of Korea (Byunsan, 35.37N; 126.27E) during AD and non-AD periods in 2004. The coarse particle (> $2{\mu}m$) number density during an AD event were 170 times higher than those of the non-AD counterpart. The average net-count of silica in individual particles collected on AD event was roughly 11 times higher than that of non-AD counterpart. The X-ray net-counts of trace elements (Zn, Co, Mn, and V) were also considerably high in AD relative to the non-AD day. Particle classification based on the inter ratio analysis of elemental net-count suggests that a large portion of the coarse particles collected during AD event underwent chemical transformation to a certain degree. The visual interpretation of micro-PIXE elemental maps and elemental localization data in and/or on individual AD particles clarified the internal mixture of AD particles with sea-salt and artificial metallic particles.

• 한국주거학회논문집
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• 제27권6호
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• pp.95-104
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• 2016

The purpose of this research is to compare housing wealth effects of home-owning single income couples (SIC) and dual income couples (DIC) on their non-durable consumption and to assess the effects by location, age groups, housing structure type, debt-to-asset ratio and employment status. Using the Korean Labor and Income Panel Study (KLIPS) of 2014, this empirical study identified 1,198 SIC households and 1,044 DIC households, and employed multiple regression analysis. The main results reveal that the difference of financial portfolios between SIC and DIC households was little but housing wealth effects were stronger among SIC households than DIC counterpart. It's evident that housing wealth effects were conspicuous for SIC and DIC households who were headed by wage earners aged over 40s, and resided in apartment outside the Seoul Metropolitan Area. However, household debt became a determinant in contradicting housing wealth effects of SIC and DIC households. While the household financial dimension was in proportion to income, DIC households didn't gain much financial security due to increasing expenditure. Further, this research imply that liquidity constraints explicitly posed a more serious threat to SIC households whose dependence on housing asset is larger than their counterpart.

• Architectural research
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• 제11권2호
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• pp.9-18
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• 2009

This research started from the premise that East Asia - China, Korea and Japan - played a remarkable role in the development of modern architecture. In this study, attention is paid to the lack of a synthetic research about the influence of East Asia on European modernism as a counterpart to its influence on American modernism. Thus, the intention of this paper is to construct an integrated discourse on the East Asian contribution to European modern architecture. By analyzing recently published/presented articles on the related subjects, this study suggests how European modernists encountered the East, what attracted them to the East, and how they applied East Asian aesthetics in their designs. While a number of architects adopted East Asian formal elements directly, at times superficially, others extracted the underlying principles. As a whole, this analysis offers insights at several levels. First, it provides a balance to the view of the East Asian influence on modern architecture by providing an investigation into its influence on European modernism as a counterpart to its influence on American modernism. Second, the multi-faceted nature of modern architecture is further illuminated in this study. Third, an important example of "positive-Orientalism" is provided, which contrasts with the rather negative image implied by E. Said's 'Orientalism'. In conclusion, this paper provides a critical assessment of the fundamental motive of European modernists' adoption of East Asian aesthetics.