• Title/Summary/Keyword: global

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Dynamics of alpine treelines: positive feedbacks and global, regional and local controls

  • Kim, Jong-Wook;Lee, Jeom-Sook
    • Journal of Ecology and Environment
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    • 제38권1호
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    • pp.1-14
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    • 2015
  • Whilst it is clear that increasing temperatures from global environmental change will impact the positions of alpine treelines, it is likely that a range of regional and local scaled factors will mediate the overall impact of global scale climate drivers. We summarized 12 categories of abiotic and biotic factors as 4 groups determining treeline positions. First, there are global factors related to climate-induced growth limitation and carbon limitation. Second, there are seven regional and local factors related to treeline dynamics including frost stress, topography, water stress, snow, wind, fire and non-fire disturbance. Third, species-specific factors can control treeline dynamics through their influence on reproduction and life history traits. Fourth, there are positive feedbacks in structuring the dynamics of treelines. Globally, the commonly accepted growth limitation hypothesis is that growth at a treeline is limited by temperature. Meanwhile, positive feedbacks between canopy cover and tree establishment are likely to control the spatial pattern and temporal dynamics of many treelines. The presence of non-linear dynamics at treelines has implications for the use of treelines as barometers of climate change because the lagged responses and abrupt shifts inherent in non-equilibrium systems may combine to mask the overall climate trend.

자기-지각의 발달적 변화 (Developmental Change of the Self-Perception)

  • 이영환
    • 대한가정학회지
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    • 제35권5호
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    • pp.61-72
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    • 1997
  • The purpose of this study was to examine the developmental changes about self-perception from childhood to adult period. The subjects were 365 of 5th graders in elementary school, the 2nd graders in junior and senior high school, sophomore in college, and adults. The instruments used for this study were Harter's Self-Perception Profile for the children, adolescences, college students, and adults. The results were as follows. 1. From elementary school to junior high school, the score of scholastic, athletic, physical appearance, behavioral conduct, and global self-worth were decreased. At the developmental perspective, the junior high school students were highly anxious for self-perception. 2. Physical appearance were the best predictor of the global self-worth for all developmental stages. 3. Physical appearance, behavioral conduct predicted more about the global self-worth than any other factors for elementary and junior high school students. And for junior high school students, social acceptance and friendship also predicted about the global self-worth. Scholastic competence showed higher correlation with global self-worth for the senior high school and college students than elementary and junior high school students. 4. For college students, males had higer scores than females on ability-oriented but also relationship-oriented subscales. But the adults showed no differences in nurturance, household management, job competence depending on sex.

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Removal of BP-3 Endocrine Disrupting Chemical (EDC) using cellulose acetate and ZnOnano particles mixed matrix membranes

  • Rajesha, B.J.;Chandan, H.R.;Sunil, K.;Padaki, Mahesh;Balakrishna, Geetha R.
    • Membrane and Water Treatment
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    • 제7권6호
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    • pp.507-520
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    • 2016
  • The effect of ZnO on cellulose acetate in the removal of benzophenone-3 (BP-3) was investigated. The benzophenone-3 (BP-3) which is an endocrine disrupting chemical (EDC) was completely removed (100%) from the drinking water using Cellulose Acetate (CA) and zinc oxide (ZnO) composite membranes. The membranes were prepared by DIPS method and the filtration experiments were conducted by dead end filtration unit. The macrostructure of the membrane were studied by ATR-IR and XRD Spectra's. Atomic force microscopy (AFM) and Scanning electron microscopy (SEM) were used to study the micro properties of the membranes. The laboratory experiments such as water uptake study and pure water flux performed to confirm the increasing hydrophilicity. The enhancing hydrophilicity was confirmed with respect to higher the concentration of nanoparticles. Evaluation of BP-3 removal was carried in different experimental conditions, such as, different Trans membrane pressure and different concentration of feed. The membrane with low pressure showed better performance by rejecting 100% of BP-3. However, 1 ppm, 3 ppm and 6 ppm of feed solution was used and among them 3 ppm of feed solution gives 100% rejection. The ZnO nanoparticales enhances the performance of CA membrane by showing maximum rejection.

덤프의 이동경로 모니터링을 통한 생산성 분석 (Productivity Analysis on Real-time Path Monitoring of Dumps)

  • 이학준;권영민;윤차웅;서종원
    • 대한토목학회논문집
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    • 제36권3호
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    • pp.565-571
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    • 2016
  • 본 연구에서는 GIS 기반의 오픈 Global Map을 이용하여 공사현장과 토취장의 위치를 확인하고, 덤프와 그레이더 등의 건설장비에 GPS(Global Positioning System)를 부착하여 장비의 실시간 위치, 속도, 고도, 방향등의 Data를 이용하여 실시간 모니터링을 진행하고, Data를 이용하여 생산성 분석을 진행하여 최적 장비 대수를 도출하고 시공단계에서 실시한 설계단가와 모니터링을 통한 장비 생산량으로 도출된 총 경비와 비교한 결과 총 경비 30%정도 적게 나오는 것을 알 수 있었다.

전구 모델의 물리과정에 따른 태풍 모의 민감도 (Sensitivity of Typhoon Simulation to Physics Parameterizations in the Global Model)

  • 김기병;이은희;설경희
    • 대기
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    • 제27권1호
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    • pp.17-28
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    • 2017
  • The sensitivity of the typhoon track and intensity simulation to physics schemes of the global model are examined for the typhoon Bolaven and Tembin cases by using the Global/Regional Integrated Model System-Global Model Program (GRIMs-GMP) with the physics package version 2.0 of the Korea Institute of Atmospheric Prediction Systems. Microphysics, Cloudiness, and Planetary boundary Layer (PBL) parameterizations are changed and the impact of each scheme change to typhoon simulation is compared with the control simulation and observation. It is found that change of microphysics scheme from WRF Single-Moment 5-class (WSM5) to 1-class (WSM1) affects to the typhoon simulation significantly, showing the intensified typhoon activity and increased precipitation amount, while the effect of the prognostic cloudiness and PBL enhanced mixing scheme is not noticeable. It appears that WSM1 simulates relatively unstable and drier atmospheric structure than WSM5, which is induced by the latent heat change and the associated radiative effect due to not considering ice cloud. And WSM1 results the enhanced typhoon intensity and heavy rainfall simulation. It suggests that the microphysics is important to improve the capability for typhoon simulation of a global model and to increase the predictability of medium range forecast.

혈부축어탕(血府逐瘀湯)이 흰쥐의 전뇌허혈에 미치는 영향 (Neuroprotective Effects of Hyulbuchookau-tang(血府逐瘀湯) on Global Cerebral Ischemia of the Rats)

  • 조은희;김영균;권정남
    • 대한한의학회지
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    • 제28권2호통권70호
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    • pp.44-53
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    • 2007
  • Objectives : This study examined the neuroprotective effect of Hyulbuchookau-tang (血府逐瘀湯, HBCAT) against neural damage following global cerebral infarction. Methods : Sprague-Dawley rats were induced with global cerebral infarction by occlusion of the bilateral common carotid artery with hypotension (CCAO). The rats were divided into 3 groups. We treated extract of HBCAT to one group after operation (sample group), one group wasn't induced with ischemic damage after operation (sham group), and one group was induced with ischemic damage after operation (control group) but not treated. We observed neurological scores and cresyl violet-stained hippocampus CAl area, TUNEL-positive neurons, and Bax-positive neurons in brain regions. Results : HBCAT treatment after CCAO increased pyramidal neurons in CAl hippocampus induced by CCAO. HBCAT treatment after CCAO reduced Bax-positive neurons in CAl hippocampus of brain regions induced by CCAO. HBCAT treatment after CCAO wasn't effective for HSP70-positive neurons in CAl hippocampus induced by CCAO. Conclusions : These results suggest that HBCAT has a neuroprotective effect against global cerebral ischemia.

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벤처·중소 ICT 기업의 디지털 생태계에서의 글로벌 경쟁력 요인 연구 (A Study of the Competitive Factors of ICT Venture and SMEs in the Global Digital Ecosystem)

  • 이계수;윤현덕
    • 한국IT서비스학회지
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    • 제15권1호
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    • pp.1-18
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    • 2016
  • Recently, in the bio-field success stories of ventures through a biosimilar technology is being excavated. but the growth of ICT industry has been stagnant since reaching a boom in the dissemination of early high-speed internet in 2000s. The purpose of this study is to explore the factors of change of business model and business strategy of ICT ventures and SMEs with the evolution of the digital ecosystem, and to drive the factors to be competitive on the global value chain. The researcher selected an entreprenuership, market-innovation orientation, technology-innovation orientation, and Administration-innovation orientation as internal factors influencing the global competence and healthiness of the ecosystem as external factors. The researcher applied samples of 94 ICT Venture and SMEs to a research model, and adopted 5 hypotheses. The researcher believes that only a few hypotheses were adopted because it takes time for overall innovation orientation of ICT Venture and SMEs to result in the real global competence as the their innovation orientation is still on the level of domestic market. And the researcher also thinks that only healthiness of the ecosystem affected management performances because the companies' performances of the last 3 years were so weak that the correlation between innovation orientation of each company and the performances were not big enough.

배선 밀집도를 완화하기 위한 개선된 광역배치 기법 (Improved Global Placement Technique to Relieve Routing Congestion)

  • 오은경;허성우
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제14권4호
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    • pp.431-435
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    • 2008
  • 기존의 CDP(Congestion Driven Placement) 기법[1]은 배선 밀집도에 크게 기여하는 넷에 속한 모든 셀들을 옮길 때 가능한 방향을 모두 고려하기 때문에 CPU 시간을 많이 소모한다. 본 논문에선 배선 밀집도를 완화하기 위한 빠른 배치 기법, 즉 ICDGP(Improved Congestion Driven Global Placement)라 불리는 개선된 기법을 제안한다. ICDGP는 밀집된 지역에 있는 넷에 속한 셀들의 이동 목표 지점을 정하기 위해 force-directed 기법을 사용하며, 각 셀은 이동 목표 지점으로만 옮기는 것을 고려한다. ICDGP는 또한 셀을 하나씩 옮기는 것보다 다수의 셀을 동시에 같이 옳기는 것이 낫다고 판단되면 같이 옮긴다. 실험 결과에 의하면 CDP보다 ICDGP가 배선 밀집도 면에서 좋은 배치를 생성한다. 특히 CPU 시간은 평균 36% 개선되었다.

INTENSIVE OBSERVATION OF SAND AND DUST STORMS USING GROUND-BASED FOURIER TRANSFORM INFRARED SPECTROSCOPY IN ANMYEON, KOREA

  • Lee, Byung-Il;Kim, Yoon-Jae;Sohn, Eun-Ha;Kim, Mee-Ja;Lee, Kwang-Mog;Park, Joong-Hyun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.142-145
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    • 2007
  • In order to analyze hyper-spectral properties of Sand and Dust Storm (SDS), dust observation experiment has been performed at the Korea Global Atmosphere Watch Center (KGAW) in Anmyeon form early March to middle of May, 2007. We measured down-welling radiances by using ground-based Fourier Transform Infrared Spectroscopy (FT-IR) at the time of overpass of AIRS. And radiative transfer model simulation has been carried out to estimate the effects of size distribution, components, and altitude of SDS over the high resolution infrared spectrum in the range of 500-1500 $cm^{-1}$ with a line-by-line radiative transfer model and compared them with FT-IR and AIRS/Aqua observing data.

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Local and Global Information Exchange for Enhancing Object Detection and Tracking

  • Lee, Jin-Seok;Cho, Shung-Han;Oh, Seong-Jun;Hong, Sang-Jin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권5호
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    • pp.1400-1420
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    • 2012
  • Object detection and tracking using visual sensors is a critical component of surveillance systems, which presents many challenges. This paper addresses the enhancement of object detection and tracking via the combination of multiple visual sensors. The enhancement method we introduce compensates for missed object detection based on the partial detection of objects by multiple visual sensors. When one detects an object or more visual sensors, the detected object's local positions transformed into a global object position. Local and global information exchange allows a missed local object's position to recover. However, the exchange of the information may degrade the detection and tracking performance by incorrectly recovering the local object position, which propagated by false object detection. Furthermore, local object positions corresponding to an identical object can transformed into nonequivalent global object positions because of detection uncertainty such as shadows or other artifacts. We improved the performance by preventing the propagation of false object detection. In addition, we present an evaluation method for the final global object position. The proposed method analyzed and evaluated using case studies.