• 한국산림과학회지
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• 제99권6호
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• pp.827-835
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• 2010

기후변화협약 대응을 위한 산림의 임목축적량과 변화량 탐지의 측면에서 국가산림자원조사는 신뢰성있는 산림통계량을 산출하기 위한 기반자료로서의 결정적인 역할을 담당하고 있다. 그러나 많은 정보들이 아직 행정구역단위 통계로만 산출되고 있어 산림 통계량의 공간적 분포와 같은 정보를 제공해주지는 못하고 있다. 따라서 본 연구는 국가산림자원조사 자료를 이용해 임상특성별 임분재적 추정모델을 개발하고, 임상도와 통합하여 임분재적의 공간분포를 추정하는 것을 목표로 하였다. 산림의 임분재적 추정모델 개발을 위해 연구대상지에 포함된 국가산림자원조사 자료를 이용하여 표본점별 임분재적과 흉고단면적합을 산출하고, 표본점의 임황정보(수종, 경급, 영급, 소밀도)를 모델개발에 활용했다. 결과적으로 수종, 영급, 소밀도 기준에 따른 임분재적 모델이 구축되었으며, 본 모델을 임상도에 적용해 임분재적 주제도와 불확실성 주제도를 제작했다. 임분재적 주제도에 의한 연구대상지의 평균 임분재적은 85.7 $m^3$/ha이며, 95% 신뢰구간을 고려했을 때 약 79.7~91.8 $m^3$/ha 구간에 포함되는 것으로 나타났다.

• 한국물환경학회지
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• 제34권1호
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• pp.10-25
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• 2018

This study was conducted to estimate the habitat suitability of 17 benthic macroinvertebrate taxa in the Hwayang stream. Habitat Suitability Index (HSI) of benthic macroinvertebrates from the Hwayang stream was developed based on three physical habitat factors which include current velocity, water depth, and the substrate. The Weibull model was used as a probability density function to analyze the distribution of individual abundance by physical factors. The number of species and the total individual abundance increased along with the increase in current velocity. By means of Canonical Correspondence Analysis (CCA), the relative importance of each factor was determined in the following order: current velocity, water depth, and the mean diameter. The results depicted that, the most influential factor in the growth of benthic macroinvertebrates in the Hwavang system was current velocity. After comparing the analyzed results from the Hwayang stream with the resukts from the Gapyeong stream, the integrated HSI was drawn. The results indicated that current velocity and substrate had similar distributions of HSI in the two streams. This was due to the addition of unmeasured data from previous surveys, or the fact that benthic macroinvertebrates adapted to deeper waters in the Hwayang Stream. Most taxa showed a clear preference for a fast current velocity, deep water depth and coarse substrate except Baetiella, Epeorus, (mayflies), and Hydropsyche (caddisfly).

• 천문학회보
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• 제38권2호
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• pp.64.1-64.1
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• 2013

High energy photons and mechanical energy produced by the process of star formation result in copious FIR molecular and atomic lines, which are important coolants of the system. Photons thermally or mechanically induced could dissociate water in the dense envelope to change relative abundances among the species O, OH, and H2O. Here we analyze OH emission lines toward embedded young stellar objects (YSOs) observed as part of the Herschel open time key program, 'Dust, Ice, and Gas In Time (DIGIT)' in order to study the physical conditions of associated gas and the energy budget loaded on the OH line emission. According to our analysis of the Herschel/PACS spectra, OH emission peaks at the central spaxel in most of sources, but several sources show spatially extended emission structures. In the extended emission sources, the distribution of OH emission is correlated with that of [OI] emission and extended along the outflow directions. Considering the diversity of source properties, ratios between detected OH lines are relatively constant among sources. In addition, each OH line has strong correlation with bolometric luminosity. For detail analyses with rotation diagram and non-LTE LVG model, we present the results from GSS30-IRS1 and Elias29.

• 한국수산과학회지
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• 제44권4호
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• pp.390-396
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• 2011

Southern rough shrimp Trachysalambria curvirostris is exploited mainly by small shrimp beam trawl in coastal regions of Korea. To determine the size selectivity of a shrimp beam trawl for this species, a series of comparative fishing experiments was conducted in the sea adjacent to Geoje Island off the southern cost of Korea in June and November, 2010, using codends with four different mesh sizes(14.2, 17.8, 25.5, and 35.3 mm). The extended Share Each Length's Catch Total(SELECT) analysis method, based on a multinomial distribution, was applied to the fishing data to obtain a master selection curve. The model with the estimated split parameters fit the catch data best. The master selection curve was estimated to be: s(R)=exp(15.183R-7.872)/[1+exp(15.183R-7.872)], where the relative carapace length, R, is the ratio of carapace length to mesh size. The relative carapace length for 50% retention was 0.518, and the selection range was 0.145. The results suggest that codends with a larger mesh size allow more small-sized shrimps to escape.

• Spatial Information Research
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• 제12권3호
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• pp.263-274
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• 2004

본 연구의 목적은 GIS 분석기법에 의해 적조의 발생시기와 생물학적, 해양학적인 인자를 통해 적조의 발생 가능한 시-공간적인 분포를 분석하는 적조정보시스템의 개발이다. 적조의 발생은 1994년까지 남해안에서 산발적으로 일어났다. 그러나 1995년 이후로 남해안과 동해안 전 해역에 걸쳐서 빈번히 광역적인 범위로 적조가 발생하고 있다. 따라서 적조 연구 분야도 최근 중요한 변화가 이루어졌다. 적조 모니터링을 위한 원격탐사, GIS, 퍼지 모델 시스템 등과 같은 다양한 기술 분야가 수행되었다. 본 연구에서는 국내 연안에서 발생한 적조의 발생 범위와 적조 생물, 그리고 해양환경 요소 등을 하나의 지리정보시스템 기반에 의한 적조정보시스템으로 구축하기 위해 각각의 자료를 데이터베이스화하고 적조발생의 공간적 분포를 분석하는데 필요한 자료의 구축 방안을 제시하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1572-1577
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• 2003

High-power pulsed laser ablation under atmospheric pressure is studied utilizing numerical and experimental methods with emphasis on recondensation ratio, and the dynamics of the laser induced vapor flow. In the numerical calculation, the temperature pressure, density and vaporization flux on a solid substrate are first obtained by a heat-transfer computation code based on the enthalpy method, and then the plume dynamics is calculated by using a commercial CFD package. To confirm the computation results, the probe beam deflection technique was utilized for measuring the propagation of a laser induced shock wave. Discontinuities of properties and velocity over the Knudsen layer were investigated. Related with the analysis of the jump condition, the effect of the recondesation ratio on the plume dynamics was examined by comparing the pressure, density, and mass fraction of ablated aluminum vapor. To consider the effect of mass transfer between the ablation plume and air, unlike the most previous investigations, the equation of species conservation is simultaneously solved with the Euler equations. Therefore the numerical model computes not only the propagation of the shock front but also the distribution of the aluminum vapor. To our knowledge, this is the first work that employed a commercial CFD code in the calculation of pulsed ablation phenomena.

• 한국물환경학회지
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• 제33권3호
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• pp.311-325
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• 2017

Habitat suitability index (HSI) of 17 benthic macroinvertebrate taxa, which were lotic insects of generic category except Potamanthidae in mayfly, was developed for three physical habitat factors (current velocity, water depth and substrate) based on an ecological monitoring in a Korean stream (Gapyeong). Weibull model was used as a probability density function to analyze the distribution of individual abundance related with physical factors, which showed it was so available. Number of species and total individual abundance increased along with the increase of current velocity and the mean diameter of substrate, and decreased along with the increase of water depth. Most taxa showed a clear preference for a fast current velocity, shallow water depth and coarse substrate except Ephemera, Potamanthidae (mayfly), and Plectrocnemia (caddisfly) which were rheophobic, potamophilic and lithophobious. Based on the canonical correspondence analysis, the relative importance of each factor was determined as follows: current velocity > substrate > water depth.

• 대한기계학회논문집B
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• 제32권9호
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• pp.683-694
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• 2008

The performance and durability of Polymer Electrolyte Fuel Cells (PEFCs) are strongly influenced by the uniformity of current density, temperature, species distributions inside a cell In order to obtain uniform distributions in them, the optimal design of flowfield must be a key factor. In this paper, the numerical study of land/channel flowfield optimizations is performed, using a multi-dimensional, multi-phase, non-isothermal PEFC model. Numerical simulations reveal more uniform current density and HFR(High Frequency Resistance) distributions and thus better PEFC performance with narrower land/channel width where the less severe oxygen depletion effect near the land region and more uniform contact resistance variation along the in-plane direction are achieved. The present study elucidates detailed effects of land/channel width and assist in identifying optimal flow-field design strategies for the operation of PEFCs.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2765-2770
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• 2011

Organic dye-doped glasses, viz., ruthenium (II) tris(4,7'-diphenyl-1,10'-phenanthroline) $[Ru(dpp)_3]^{2+}$ incorporated into thin silica xerogel films produced by the sol-gel method, were prepared and their $O_2$ quenching properties investigated as a function of the $[Ru(dpp)_3]^{2+}$ concentration (3-400 ${\mu}M$) within the xerogel. The ratio of the luminescence from the $[Ru(dpp)_3]^{2+}$-doped films in the presence of $N_2$ and $O_2$ ($I_{N2}/I_{O2}$) was used to describe the film sensitivity to $O_2$ quenching. ($I_{N2}/I_{O2}$ changed three-fold over the $[Ru(dpp)_3]^{2+}$ concentration range. Time-resolved intensity decay studies showed that there are two discrete $[Ru(dpp)_3]^{2+}$ populations within the xerogels (${\tau}_1$ ~ 300 ns; ${\tau}_2$ ~ 3000 ns) whose relative fraction changes as the $[Ru(dpp)_3]^{2+}$ concentration changes. The increased $O_2$ sensitivity that is observed at the higher $[Ru(dpp)_3]^{2+}$ concentrations is a manifestation of a greater fraction of the 3000 ns $[Ru(dpp)_3]^{2+}$ species (more susceptible to $O_2$ quenching). A model is presented to describe the observed response characteristics resulting from $[Ru(dpp)_3]^{2+}$ distribution within the xerogel.

• 한국수산과학회지
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• 제37권3호
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• pp.249-254
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• 2004

The hydro-acoustic method is widely used for estimating biomass and distribution of fisheries resources along the coast and in the ocean. High costs and time are necessary to construct systems for this method and to initially educate specialists. It has been used in fisheries of advanced nations like Japan and Norway, because it is more efficient than other methods. In order to research the behavior of fish around an artificial reef using an echo sounder, volume backscattering strength (SV) and fish per cubic meter (FPCM) of darkbanded rockfish around the model artificial reef in a water tank were measured. Moreover, behavior of fish was observed in an adjacent artificial reef, which was constructed at Tongyeong marine ranching area. Following that, an acoustics survey was conducted at Mirukdo around the Tongyeong marine ranching area, in order to understand the spatial distribution and strength of fisheries resources. Very high patches of fish were found in a wide area around the artificial reef. It is thought that an approaching fish school around the artificial reef can be measured accurately by using an echo sounder of high resolution. Moreover, use of other monitoring methods like of diving or ROV simultaneous with an echo sounder is required in order to grasp the species and ecology of fish inhabiting the area around the artificial reef.