• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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• pp.24.2-24.2
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• 2008

We have examined the relative contributions of representative space weather proxies (geomagnetic aa index) to global warming (Global temperature anomaly) and compared them with that of green house effect characterized CO2 content from 1868 to 2005. For this we used Hadcrut3 temperature anomaly (Ta) data, aa index taken at two anti-podal subauroral stations (Canberra Australia and hartland England), and the CO2 data come from historical ice core records. From the comparison between Ta and aa index, we found several interesting results: (1) the linear correlation coefficient between two parameters increases until 1990 and then decreases rapidly, and (2) the scattered plots between two parameters shows different patterns before and after 1990. A partial correlation of Ta and two quantities (aa, CO2) also shows that the geomagnetic effect (aa index) is dominant until about 1990 and the CO2 effect becomes much more important after then. These results imply that the green house effect become very important since at least 1990. For a further analysis, we simply assume that Ta (total) = Ta (aa) + Ta (CO2) and made a linear regression between Ta and aa index from 1868 to 1990. A linear model is then made from the linear regression between energy consumption (a proxy of CO2 effect) and Ta (total) - Ta (aa) since 1990. This linear model makes it possible to predict the temperature anomaly in 2030, about 1 degree higher than the present temperature, which is much larger than in the previous century.

• 천문학회보
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• 제41권2호
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• pp.51.2-51.2
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• 2016

Hayabusa, the Japanese asteroid sample returning mission, acquired more than 1400 scientific images of its target asteroid (25143) Itokawa using the Asteroid Multi-band Imaging Camera (AMICA). It took images at a wide coverage of the phase angle a (Sun-Itokawa-Hayabusa) from $a{\sim}0^{\circ}$ to ${\sim}35^{\circ}$, providing a unique opportunity for studying the opposition effect (a sharp surge in brightness of asteroidal surface). Here we present a study of the opposition effect on Itokawa using the AMICA multi-band data. We found that (1) the opposition strength near the opposition is independent of the incident/emission angles of the light, also (2) it weakly depends on the wavelength showing the strongest surge around 0.7 um, and (3) the reflectance increases linearly at a>$1.5^{\circ}$ while nonlinearly at a<$1.5^{\circ}$ as approaching the opposition point. In particular, we noticed that the increasing rate has a correlation with the reflectance in the nonlinear domain whereas no detectable correlation with the reflectance in the linear domain. From these results, we conjecture that the coherent backscattering opposition effect is a dominant mechanism for the nonlinear opposition surge at a<$1.5^{\circ}$ while shadow hiding opposition effect is responsible for the linear opposition surge at a>$1.5^{\circ}$.

• 대한조선학회논문집
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• 제48권6호
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• pp.581-591
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• 2011

This paper describes the air compressibility effect in the CFD simulation of water impact load prediction. In order to consider the air compressibility effect, two sets of governing equations are employed, namely the incompressible Navier-stokes equations and compressible Navier-Stokes equations that describe general compressible gas flow. In order to describe violent motion of free surface, volume-of-fluid method is utilized. The role of air compressibility is presented by the comparative study of water impact load obtained from two different air models, i.e. the compressible and incompressible air. For both cases, water is considered as incompressible media. Compressible air model shows oscillatory behavior of pressure on the solid surface that may attribute to the air-cushion effect. Incompressible air model showed no such oscillatory behavior in the pressure history. This study also showed that the CFD simulation can capture the formation of air pockets enclosed by water and solid surface, which may be the location where the air compressibility effect is dominant.

• Structural Engineering and Mechanics
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• 제76권6호
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• pp.709-724
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• 2020

The typical inerter system, the tuned viscous mass damper (TVMD), has been proven to be efficient. It is characterized by an energy-dissipation-enhancement effect, whereby the dashpot deformation of TVMD can be amplified for enhanced energy dissipation efficiency. However, existing studies related to TVMD have mainly been performed on elastic structures, so the working mechanism remains unclear for nonlinear structures. To deal with this, an energy-spectrum analysis framework is developed systematically for classic bilinear hysteretic structures with TVMD. Considering the soil effect, typical bedrock records are propagated through the soil deposit, for which the designed input energy spectra are proposed by considering the TVMD parameters and structural nonlinear properties. Furthermore, the energy-dissipation-enhancement effect of TVMD is quantitatively evaluated for bilinear hysteretic structures. The results show that the established designed input energy spectra can be employed to evaluate the total energy-dissipation burden for a nonlinear TVMD structure. Particularly, the stiffness of TVMD is the dominant factor in adjusting the total input energy. Compared with the case of elastic structures, the energy-dissipation-enhancement effect of TVMD for nonlinear structures is weakened so that the expected energy-dissipation effect of TVMD is replaced by the accumulated energy dissipation of the primary structure.

• 생태와환경
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• 제52권4호
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• pp.348-357
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• 2019

여름철 집중 강우량 감소에 따른 저서성 대형무척추동물 군집 변화를 알아보기 위하여 섬진강 본류 25지점을 대상으로 2014년과 2015년 각각 5월과 9월 총 4회 조사를 실시하였다. 서식환경에 중요하게 작용하는 요인인 강우량, 기온, 수질, 수심, 유속, 하상구성을 수집하고 측정하였다. 섬진강의 5월 누적강우량(CP)은 2014년 2,322.1 mm, 2015년 2,371.0 mm로 큰 차이를 보이지 않았으나, 9월 CP는 2014년 7,678.2 mm, 2015년 3,726.1 mm로 반절 이상 감소하였다. 여름철 집중강우로 인한 유실효과로, 개체밀도와 종 수는 5월이 9월보다 높았다. 5월은 깔따구류와 세갈래하루살이, 9월은 네점하루살이, 두점하루살이, 세갈래하루살이가 우점을 차지하였다. 생물지수와 환경요인과의 상관성 분석 결과, 하상구성 및 유속과 상관성이 있는 것으로 나타났다. 저서성 대형무척추동물 우점종과 환경요인과의 집괴분석한 결과 5월과 9월의 CP와 MT에 따라 4 그룹으로 나뉘었다. 주성분 분석 결과 집괴분석으로 나뉘어진 그룹의 특성을 잘 반영하였으며, 특히 네점하루살이와 두점하루살이는 강우량의 변동을 잘 반영하였다.

• 한국통신학회논문지
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• 제37C권11호
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• pp.1064-1076
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• 2012

본 연구는 국제표준화에서의 성공 결정요인을 도출하고 요인간의 관계를 파악하기 위하여 문헌연구를 통하여 결정요인을 파악하고 설문조사에 기반을 둔 구조방정식 분석을 통하여 요인간의 관계를 추정하였다. 탐색적 요인 분석과 확인적 요인분석을 통하여 6개의 요인, 즉 '정부의 지원(직접)', '정부의 지원(간접)', '표준기구 활용', '표준화 전략', '시장지배력 확보', 그리고 '국제표준채택'이 추출 및 설정되었다. 분석결과 첫째, 정부의 직간접적 지원은 국제표준 채택에 직접적인 효과를 나타내지 않지만 시장지배력 확보와 같은 중간 매개요인을 통하여 국제표준 채택에 간접적으로 영향을 나타내고 있다. 둘째, 시장지배력 확보는 국제표준 채택에 가장 중요한 효과를 끼치므로 정부는 대상 표준의 연관 시장지배력을 확보하도록 선도적 시장진출, 고품질의 표준개발을 통한 시장의 만족도 증가, 잠김효과(lock-in effect)의 확대, 그리고 유사수직통합 시스템 구축을 통한 시장지배력 확보에 대한 적극적 전략을 구사해야 한다. 셋째, 공식표준화기구에서의 국제표준 채택을 위해서는 정부의 직접지원이 가장 중요하며, 사실상표준화기구에서의 국제표준 채택은 표준화기구 자체의 전략적 활용이 중요하다.

• 한국작물학회지
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• 제53권spc호
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• pp.58-64
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• 2008

Cyanidin-3-glucoside(C3G) 고함유 흑자색미 계통을 육성하기 위해 흑진주, 수원425호, 상해향혈나, 용금1호, C3GHi 품종 및 계통들 간에 완전이면교배에서 얻은 20개 조합 $F_1$의 현미 천립중과 C3G함량에 대한 diallel analysis 및 조합 능력 분석 결과는 다음과 같다. 1. 교배모본의 현미 천립중은 16.6 g(흑진주) - 30.4 g(상해향혈나)이고, 현미 100 g당 C3G 함량은 C3GHi가 흑진주의 5배 정도 높은 1043.5 mg으로 나타났다. 2. 완전이면교배 결과 현미 천립중과 C3G 함량은 비대립 유전자 효과는 나타나지 않았고, 유전자의 상가적 및 우성적 유전효과만 인정되었다. 3. 현미 천립중과 C3G 함량의 유전 양식은 두 형질 모두 상가적 및 우성효과에 의한 부분우성을 보였으며, 평균 우성정도는 각각 0.80 및 0.69였고, 교배모본에서 정의대립 유전자 비율이 높았으며, 우성친의 빈도가 높고, 후대에서는 감소하는 방향으로 작용하였다. 4. 두형질의 상가적 유전효과에 의한 협의의 유전력은 각 각 0.66, 0.70이고, 광의의 유전력은 각각 0.98, 0.98로 높게 나타났다. 5. 현미 천립중에 대한 일반조합능력 효과는 상해향혈나가 가장 높았고, 흑진주가 가장 낮았으며, 흑진주/수원425 호, 수원425호/C3GHi 조합의 특정조합능력 효과가 가장 높았다. 6. C3G함량에 대한 일반조합능력 효과는 C3GHi가 가장 높았고, 상해향혈나가 가장 낮았으며, 흑진주/C3GHi 조합에서 특정조합능력 효과가 가장 낮게 나타났다.

• 한국조경학회지
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• 제20권1호
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• pp.80-94
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• 1992

To inspect the changing of the forest soil and plants community structrure by air plooutand & acid rain during from September to November in 1990, the smapling sites were selected in the Piwon, Namsan and Kwangnung forest. In sites, plots were set up in Q. aliena forest at Piwon, Quercus mongolica and Pinus densiflora forest at Namsan and Q. mongolica and Pinus densiflora forest at Kwangnung. To obtain the individual number of trees, number of species, importance values and species diversity, using the Curtis & McIntosh methods. The results are following that; 1) In Pinus densiflora community, it was almost dominated by Q. spp. in the canopy layer and P. densiflora and Carpinus laxiflora through the subtree to shrub layer at Kwangnung. It wassaid that C. laxiflora is the climax species in moddle temperature zone. On the contrary, in Namsan forest, there is no appearance thesamplings of P. densiflora & C. laxiflora, but Styrax japonica and Stephanandra incisa that are acid-tolerance species are dominant ones. On the other hand, in Q. spp. community, Q. spp. and C. laxiflora are dominant ones. On the other hand, in Q. spp. community, Q. spp. and C. laxiflora are dominant species through all layer, and in addition C. cordata somewhat appear at Kwangnung. But at Namsan and Piwon forest, Q. mongolica & Q. aliena that were dominant species in canopy layer disappeared in the subtreeand shrub layer, and C. laxiflora and Corunus cordata absolutely disappeared. It were similarly dominated by Robinia pseudo-acacia, Styrax japonica, Sorbus alnifolia, Acer pseudo-sieboldianum, Rhododendrn mucronulatum and so on at Namsn and Piwon forest. In the light of these facts, it found out that disclimax was similar between Namsan and Piwon forest. 2) Species diversity and maximum species diversity were decreased in Kwangnumg, Namsan, Piwon in order. It was xpected that vegetational community was affected by environmental pollutant. 3) As the vegetational community structure analyses, using DCA technique among the ordination, ecological successional series are stopped to Q. spp. from P. densiflora at Namsan and Piwon, but that of Kwangnung is on the way that P. densiflora, Q. alena, C. laxiflora. It was obvi ously different from Namsan and Piwon. 4) In Q. spp. & P. densiflora community, the number of woody plants inNamsan & Piwon is much less than that of Kwangnung through all Layer. Especially, Piwon shown very severe difference. Through all community, the number of individuals of Piwon and Namsan are less than that of Kwangnung. Specially, that of the shrub layer is obvious. 5) In the growth rate of trees, it found out that all sites showed the growth decline phenomena. Especially, since in 1975, there have been the micro disclimax phenomena in Q. community of Kwangnung. 6) In the Q. community, soil acidity of Namsan & Piwon measured 4.57, 4.40 respectively. It was very strong acidity and far lower than that of Kwangnung. Also the content amount of Mg++ in Namsan & Piwon forest were still lower than Kwangnung.

• Asian Pacific Journal of Cancer Prevention
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• 제13권6호
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• pp.2597-2604
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• 2012

Methylenetetrahydrofolate reductase (MTHFR) is an essential enzyme involved in folate metabolism; a single nucleotide polymorphism (SNP) C677T has been reported to be linked with altered incidences of several diseases. We here conducted a meta-analysis of 15 published epidemiological studies with a total of 7306 cases and 8062 controls to evaluate its association with prostate cancer risk with overall and subgroup analyses. No statistical relationship was found overall with any genetic model (TT vs. CC: OR = 0.80, 95%CI = [0.62, 1.04], P = 0.094; CT vs. CC: OR = 0.97, 95%CI = [0.84; 1.12], P = 0.667; Dominant: OR = 0.94, 95%CI = [0.82; 1.07], P = 0.343; Recessive: OR = 0.81, 95%CI = [0.64; 1.04], P = 0.104), but after the exclusion of several studies, we could observe the homozygote TT to confer less susceptibility to prostate cancer in carriers; moreover, different effects of the polymorphism on prostate cancer risk was detected from subgroup analysis stratified by participants' residential region: significant reduced prostate cancer risk was found to be associated with the polymorphism from Asian studies (TT vs. CC: OR = 0.47, 95%CI = [0.33; 0.67], P < 0.001; CT vs. CC: OR = 0.73, 95%CI = [0.60; 0.90], P = 0.002; Dominant: OR = 0.67, 95%CI = [0.56; 0.82], P < 0.001; Recessive: OR = 0.55, 95%CI = [0.40; 0.76], P < 0.001) while studies from Europe indicated a slight increased risk under dominant model with marginal significance (OR = 1.14, 95%CI = [0.99; 1.30], P = 0.064). Moreover, the protective effect of the polymorphism against prostate cancer was also shown by studies performed in yellow Asians (TT vs. CC: OR = 0.48, 95%CI = [0.31; 0.75], P = 0.001; CT vs. CC: OR = 0.68, 95%CI = [0.51; 0.90], P = 0.006; Dominant: OR = 0.63, 95%CI = [0.48; 0.82], P < 0.001; Recessive: OR = 0.57, 95%CI = [0.39; 0.84], P = 0.004). We propose that these phenomena should be viewed with the consideration of folate metabolism profile and different gene background as well as living habits of different populations, and more relevant studies should be conducted to confirm our hypothesis and provide a comprehensive and clear picture concerning this topic.

• 한국언론정보학보
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• 제82권
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• pp.73-103
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• 2017

이 연구는 메이커 운동과 관련된 단행본, 정책 보고서, 기사 및 칼럼 등을 비판적 담론 분석의 관점에서 살펴보며 메이커 문화를 둘러싼 담론적 지형과 사회적 실천을 분석한다. 정부 주도의 메이커 운동은 제작 문화를 경제 위기를 극복할 수 있는 '창조 경제'의 원동력으로 의미화하고, 디지털 제조업의 창업을 정책적으로 진흥하고 있다. 서울시의 경우, 정부 주도의 경제주의적 메이커 운동을 비판하면서, 기술을 통해 사회 문제를 해결하고자 하는 '디지털 사회 혁신'으로 메이커 운동을 제도화한다. 문화 예술계에서는 메이커를 장인 노동이나 손노동과 같은 '창조적 장인'으로 간주한다. 또한 지배적인 기술 구조에 대한 대항으로서 '비판적 제작 활동'을 구축하고자 하는 저항의 움직임도 있다. 하지만 지배적 담론이 현실적인 차원에 미치는 권력 효과와, 대항적 담론 투쟁으로 인한 지배 구조의 균열을 섣불리 확신할 수 없다. 현재 진행 중인 메이커 운동은 지배적인 권력 구조와 접합되어 제작 문화를 사회적 경제적 가치로 이끌어 내고자 하는 담론 전략과, 이에 대한 문화적 기술 정치적 가능성을 중시하는 대안적인, 혹은 대항적인 의미화 실천이 경합하는 갈등과 투쟁의 장이다.