• 수산해양기술연구
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• 제55권3호
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• pp.198-205
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• 2019

The small yellow croaker (Larimichthys polyactis) is one of the representative high-class fish species in Korea. The catch of small yellow croaker in adjacent water fisheries has been continuously decreasing from 59,226 tons in 2011 to 19,271 tons in 2016. The small yellow croaker is caught by gillnet, stow net and bottom trawl, among which about 55~65% is caught by gillnet. For the sustainable use of small yellow croaker, the fishing power of small yellow croaker drift gillnet is very important. Therefore, the change of fishing power index were analyzed to identify the development of the vessel and gear technology that may have improved the fishing efficiency of the small yellow croaker drift gillnet fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. The mesh size was 75.0 mm in the 1960s, but reduced to 60.6 mm in the 1980s and to 51.0 mm in the 2000s. In the 1960s, it was hauled out by manpower. However, the net hauler were modernized and supply rate was also increased since 1970. Due to the mechanization of the net hauler, the number (length) of used net gradually increased from 1.5 km in the 1960s to 7.5 km in the mid-1980s and to 15 km in 2010. Colour fish finders and positioning system were introduced and utilized from the mid-1980s. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the small yellow croaker drift gillnet fishery increased from 1.0 in 1980 to 0.8 in 1970, to 1.1 in 1990, to 1.6 in 2000 and to 1.9 in 2010. The results are expected to contribute to reasonable fisheries stock management of the small yellow croaker drift gillnet fishery.

• 한국산림과학회지
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• 제94권3호통권160호
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• pp.183-190
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• 2005

본 연구에서는 국내 시 도를 대상으로 산림의 건강성과 관리체계에 대한 산림지속성 지수를 평가하였다. 산림기본계획과 산림비전21에서 제시한 주요시책에 해당하는 69개의 항목과 주요시책에는 해당되지는 않지만 평가를 위해 필요한 15개 지표를 합친 총 84개의 후보지표를 대상으로 지표의 평가 작업을 거쳐 최종적으로 33개의 지표를 선정하였다. 이들 지표들을 대상으로 압력(pressure), 상태(state), 반응(response) 지표로 구분하여 압력과 상태는 산림의 건강성을 나타내는 지표로, 반응은 산림의 관리체계를 나타내는 지표로 구분하였다. 선정된 지표들을 대상으로 델파이조사를 통해 중요도를 부여하였다. 중요도를 이용해서는 서열합 방법에 의해 가중치를 산출하여 각 지표들의 표준화 작업에 의해 얻은 값에 적용하였다. 지수화 작업에서는 가법형에 의거해서 2002년도 각 시 도별 산림 지속성 지수를 산출하여 비교, 분석하였다. 본 연구는 기초 연구로 수행되어 해당 지자체를 언급하지는 않았으나 각 지자체들이 각 지표의 적용과 지수화 방법에 대한 합의가 이루어진다면 지자체의 산림 상태와 관리 정도를 정량적으로 평가하는 중요한 정보가 될 것으로 여겨진다.

• 수산해양기술연구
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• 제51권4호
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• pp.583-591
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• 2015

The coastal stow net (stow net hereafter) in Korea is one of the major fishing methods for yellow croaker (Larimichthys polyactis), ribbon fish (Trichiurus lepturus), and anchovy (Engraulis japonicus). In terms of energy efficiency, the stow net fishery is more competitive than towing fishing gears such as trawl gears. The fishing vessels in stow net fishery have consumed less fossil fuel and also have had less carbon dioxide emission into the atmosphere. however, the stow net fishery is necessary to be regulated due to its increased output of the fleet. Therefore, it is required for fisheries authorities to manage the fishing capacity or fishing power for the assurance of fishery's sustainability. For fisheries management authorities, it is necessary to quantify data related to fishing capacity and fishing power to deploy fishery policy in a sustainable way. In terms of data for decision-making, Data envelopment analysis (DEA) method was conducted to estimate fishing capacity. Fishing power index (FPI) was also applied to calculate relative fishing power to approach the problem in a quantitative way.

• 원예과학기술지
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• 제33권6호
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• pp.883-890
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• 2015

토양 전염균인 Fusarium oxysporum f. sp. lilii(Fol)은 식물에 심각한 위협을 주는 균으로 특히 백합의 구근과 꽃에 심각한 영향을 준다. 따라서 저항성 품종의 육성이 중요시되고 있는데, 저항성 품종이 육성되기 위해서는 신속, 간편한 검정법 체계와 유전적 다양성이 요구되는 상황이다. 본 실험에서는 기내배양시스템을 이용하여 백합의 Fol에 대한 저항성 정도를 효율적으로 검정하는 방법을 확립하고자 하였다. 병원균의 배양조건, 병원균의 식물체 접종 농도, 대상 절편체 종류, 접종 후 적정 발병 기간 등과 같은 조건을 단독, 혹은 조합하여 실험 한 결과 다음의 기내검정조건을 확립하였다. Fol균을 6일 동안 PDA 배지에서 배양한 후 포자 현탁액을 $1.0{\times}10^4$ $spores{\cdot}mL^{-1}$농도로 조절하여 기내배양 중인 식물체의 잎을 $1.5{\times}2.0cm^2$의 크기로 절단하여 $25^{\circ}C$, 암조건에서 22시간 침지시켜 접종하였다. 접종이 끝난 잎절편체는 0.6% 한천배지에 치상하여 온도 $25^{\circ}C$, 습도 50%, 16시간 광조건(광도 $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$)을 유지하면서 병의 발달을 관찰하였다. 발병 정도를 지수화하여 통계처리를 하였다. 기내검정을 통하여 저항성 및 민감성으로 선발한 백합종들을 토양검정법으로 실험한 결과 동일한 저항성 정도를 얻을 수 있었으며, 이는 본 연구에서 확립한 Fol에 대한 구근부패병 기내검정법이 효율적으로 품종 선발에 이용될 수 있음을 보여준다고 하겠다.

• 환경영향평가
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• 제17권6호
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• pp.357-366
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• 2008

It is certain that urbanization has transformed the ecological consequences severely, but urban ecosystem is not fully understood yet. Urban growth is not like a static form and it spreads spatially and temporally. Therefore in studying urban ecosystem, it is important to relate the spatial pattern of urbanization to ecological processes. Using gradient analysis, we attempted to quantify the urbanization's spatial impacts in Daejeon-city and Cheonan-city, Chungcheong-province, Korea. Because of Multifunctional Administrative City Planning (MACP), a lot of development projects are planned in Chungcheong-province, Korea. It's important to study about original cities' patterns and impacts. These results can be adopted to future city planning. So several measures such as fragmentation, vegetation index, surface temperature, population density, and income rate were computed along a 75km long and 3km wide transect. The results showed that Daejeon-city has a wider urban center, lower vegetation indexes, and higher surface temperature than Cheonan-city. Therefore in the perspective of urban environments and sustainable urbanism, it seems that Cheonan-city is better than Daejeon-city. The changes along the transect have important ecological implications, and quantifying the urbanization gradient is an important step in understanding urban ecology.

• Advances in materials Research
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• 제9권1호
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• pp.63-98
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• 2020

The novelty of this paper is the use of a simple higher order shear and normal deformation theory for bending and free vibration analysis of functionally graded material (FGM) beams on two-parameter elastic foundation. To this aim, a new shear strain shape function is considered. Moreover, the proposed theory considers a novel displacement field which includes undetermined integral terms and contains fewer unknowns with taking into account the effects of both transverse shear and thickness stretching. Different patterns of porosity distributions (including even and uneven distribution patterns, and the logarithmic-uneven pattern) are considered. In addition, the effect of different micromechanical models on the bending and free vibration response of these beams is studied. Various micromechanical models are used to evaluate the mechanical characteristics of the FG beams for which properties vary continuously across the thickness according to a simple power law. Hamilton's principle is used to derive the governing equations of motion. Navier type analytical solutions are obtained for the bending and vibration problems. Numerical results are obtained to investigate the effects of power-law index, length-to-thickness ratio, foundation parameter, the volume fraction of porosity and micromechanical models on the displacements, stresses, and frequencies.

• 대한원격탐사학회지
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• 제37권4호
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• pp.665-685
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• 2021

This study focused on the a 20-year evaluation of the dynamism of critical thermal anomalies in Busan metropolitan area prompted by unusual infrastructural development and demographic growth rate. Archived Landsat thermal data derived-LST was the major input for UTFVI and hot spot analysis (Getis-Ord Gi^*). Results revealed that the surface urban heat island-affected area has gradually expanded overtime from 23.32% to 32.36%; while the critical positive thermal anomalies (level-3 hotspots) have also spatially increased from 19.88% in 2000 to 23.56% in 2020, recording a net LST difference of > 5℃ between the maximum level-3 hotspot and minimum level-3 coldspot each year. It is been observed that thermal conditions of Busan have gradually deteriorated with time, which is potentially inherent in the rate of urban expansion. Thus, this work serves as an eye-opener to powers that be, to think and act constructively towards a sustainable thermal conform for city dwellers.

• Journal of Microbiology and Biotechnology
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• 제33권6호
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• pp.760-770
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• 2023

Continuous cropping obstacles have become a serious factor restricting sustainable development in modern agriculture, while companion planting is one of the most common and effective methods for solving this problem. Here, we monitored the effects of companion planting on soil fertility and the microbial community distribution pattern in pepper monoculture and companion plantings. Soil microbial communities were analyzed using high-throughput sequencing technology. Companion plants included garlic (T1), oat (T2), cabbage (T3), celery (T4), and white clover (T5). The results showed that compared with the monoculture system, companion planting significantly increased the activities of soil urease (except for T5) and sucrase, but decreased catalase activity. In addition, T2 significantly improved microbial diversity (Shannon index) while T1 resulted in a decrease of bacterial OTUs and an increase of fungal OTUs. Companion planting also significantly changed soil microbial community structures and compositions. Correlation analysis showed that soil enzyme activities were closely correlated with bacterial and fungal community structures. Moreover, the companion system weakened the complexity of microbial networks. These findings indicated that companion plants can provide nutrition to microbes and weaken the competition among them, which offers a theoretical basis and data for further research into methods for reducing continuous cropping obstacles in agriculture.

• 공학교육연구
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• 제26권6호
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• pp.62-70
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• 2023

The purpose of this study is to derive implications for improving related policies and evaluation criteria in the future by analyzing trends of evaluation criteria for industry-university cooperation in Korea. For this purpose, five surveys on industry-university cooperation by government departments, major general university evaluations, and evaluation indicators of specialized industry-university evaluations by the Ministry of Education were analyzed. As a result, most of the evaluation criteria for domestic industry-university cooperation have been composed of quantitative indicators and have a limited character as quantitative performance management for government projects. Although the Ministry of Education's evaluation criteria for industry-university cooperation projects has gradually changed to a segmented index considering universities, industries, and regions, it needs to be supplemented for sustainability of industry-university cooperation. In order to promote sustainable industry-university cooperation in the future, it was suggested that first, it is necessary to supplementation of qualitative Indicators considering each university's characteristics, second, the composition of indicators related to reflect on demand in the process of the cooperation, and third, to build a virtuous cycle system for future operation of evaluation criteria.

• Coupled systems mechanics
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• 제13권1호
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• pp.43-60
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• 2024

This work presents an analytical approach to investigate wave propagation in bi-directional functionally graded cantilever porous beam. The formulations are based on Touratier's higher-order shear deformation beam theory. The physical properties of the porous functionally graded material beam are graded through the width and thickness using a power law distribution. Two porosities models approximating the even and uneven porosity distributions are considered. The governing equations of the wave propagation in the porous functionally graded beam are derived by employing the Hamilton's principle. Closed-form solutions for various parameters and porosity types are obtained, and the numerical results are compared with those available in the literature.The numerical results show the power law index, number of wave, geometrical parameters and porosity distribution models affect the dynamic of the FG beam significantly.