• 한국물환경학회지
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• 제25권5호
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• pp.713-719
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• 2009

A natural wetland in the Nakdong River basin which effectively removes non-point source pollutants was investigated for 2 years to understand wetland topography, vegetation types, and water quality characteristics. The water depth of the natural wetland was in the range of 0.5~1.9 m which is suitable for the growth of non-emergent hydrophytes. The wetland has a high length to width ratio (3.3:1) and a relatively large wetland to watershed area ratio (0.057). A broad-crested weir at the outlet increases the retention time of the wetland whose hydrology is mainly dependent on storm events. The concentrations of dissolved oxygen in the growing season and the winter season showed anoxic and oxic conditions, respectively. Diurnal variations of DO and pH in the growing season were also observed due to weather change and submerged plants. COD and TP concentrations were low in the winter season due to low inflow rate and increased retention time. Increased TP concentrations in the spring season were caused by degradation of dead wetland plants. Nitrogen in the wetland was mostly in organic nitrogen form (>75%). During the growing season, ammonium concentration was high but nitrate nitrogen concentration was low, possibly due to anoxic and low pH conditions which are adverse conditions for ammonificaiton and nitrification. The results of this study can be used as preliminary data for design, operation, monitoring and management of a constructed wetland which is designed to treat diffuse pollutants in the Nakdong river watershed.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.332-339
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• 2010

Maturity and spawning of the snailfish, Liparis ochotensis was investigated based on samples collected by gill net in the East Sea of Korea from December 2008 to December 2009. The average total length of L. ochotensis was 63.4 cm and 64.1 cm for females and males, respectively. Gonadosomatic index (GSI) began to increase in July, reaching a maximum in November, then began to decrease in December. Monthly changes in the GSI values of L. ochotensis were similar for females and males. Annual reproductive cycle of this species can be divided into five successive stages in females: early growing stage (May), late growing stage (June to July), mature stage (August to September), ripe and spent stage (September to December), and recovery and resting stage (January to April). Males show four successive stages; growing stage (May to July), mature stage (August to September), ripe and spent stage (September to December), and recovery and resting stage (January to April). Relationship between total length (TL) and fecundity (F) was F=$0.00003TL^{4.002}$ ($R^2$ = 0.703), and F increased with TL. Total length at 50% group maturity was estimated to be 55.8 cm. Our findings suggest that the spawning period takes place from September to December, with the main spawning period occurring from October to December.

• 한국환경농학회지
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• 제35권4호
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• pp.302-305
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• 2016

BACKGROUND: The northeast district of China, especially Liaoning province, Jilin province, and Heilongjiang province, is one of the largest agricultural production regions in China. These regions play a significant role in ensuring food security. Accumulated temperature such as growing degree days (GDD) is an important environmental factor for plant growth and yield. Therefore, in this study, temporal and spatial distribution of GDD for maize was examined as a basis to estimate the growth and yield of maize in these regions. METHODS AND RESULTS: Meteorological date produced by NASA (MERRA-2) was used to estimate GDD of maize at this study sites. The GDD was calculated from sowing (May 1) to harvesting (Sep. 30). The average GDD of this region between 2010 and 2015 was $1323.0^{\circ}C$ day (595.3-1838.9). The spatial distribution of GDD showed a similar pattern during the different years surveyed. Double cropping for maize could be in only Liaoning province, northwestern Jilin province, and western and eastern Heilongjiang province where the GDD was over $1600^{\circ}C$day. However, The GDD in eastern Heilongjiang province was varied by year. CONCLUSION: The GDD of maize in northeast district of China was varied spatially, but similar among recent six years at the same region. This result can be used to predict growth stage and yield of maize at these regions.

• 생물환경조절학회지
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• 제12권1호
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• pp.38-44
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• 2003

플라스틱 하우스 내에서 토성과 재배조건을 달리하여 라이시메터를 이용한 용적법으로 고추의 증발산량을 구하고자 하였다. 멀칭과 사질 또는 점질양토는 무멀칭과 모래에 비하여 고추의 증산량이 높았으며, 고추의 생장과 수량을 증가시켰다. 그히고 총 관수량의 약53%∼72%가 고추의 증산에 소모되었고, 증발산량의 약 91%∼94%가 증산에 이용되었으며 증발량은 시기에 따라 크게 변하지 않았으나 생장 초기에 증산량보다 높은 편이었다. 고추의 전 생장기간 동안 증발산량은 기상조건과 생장량에 따라 다르지만, 점질양토에서 337.7∼774.3 mm, 사질양토에서 910.6 mm, 모래에서 253.1 m의 증산량을 보였다.

• 한국전자통신학회논문지
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• 제16권4호
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• pp.743-748
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• 2021

전 세계적인 인구증가와 기후변화로 인해 식량부족 문제가 대두되는 가운데 우리나라에서는 농·축산업 인구 감소 등 지속가능성 위기를 해결하기 위해 농업과 ICT를 융합한 첨단 스마트팜 기술이 활발히 연구되고 있다. 기존 스마트팜은 개별 가격경쟁력이 낮은 작물 위주로 재배하고 있다. 식품 소비구조가 고급화, 다양화되고 있으며 농산물 소비패턴의 변화에 따라 스마트팜 시스템 또한 고부가가치 특용작물 재배를 위한 최적화가 필요하다. 이를 위해 새싹인삼(새싹삼) 재배에 특화된 컨테이너형 스마트팜 환경설비를 구축하고 ICT 융합통합관리시스템을 설계하고 구현하였다. 이를 통해 ICT와 농업, 최신 기술과 농사의 융합으로 첨단농업생산구현 및 미래융합 신산업 선도가 가능하다.

• 한국산림과학회지
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• 제97권6호
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• pp.680-689
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• 2008

본 연구에서는 층층나무, 물푸레나무, 박달나무, 개벚나무, 고로쇠나무를 대상으로 차광처리를 통해 4가지 수준(상대 차광률; 전광처리구, 전광대비 65~72%, 29~40%, 7~12%)으로 광도 조건을 달리하여 광합성 특성을 조사하였다. 그 결과, 층층나무, 물푸레나무 및 박달나무는 차광처리에 의하여 광합성 능력과 엽록소 형광이 저하하여, 내음성 수준이 낮음을 시사하였다. 개벚나무는 조사 시기별 차이는 있었으나, 강피음 처리구를 제외한 나머지 세 처리구에서 좋은 광합성 능력을 나타내, 보통 수준의 내음성을 보였다. 한편 고로쇠나무는 전광대비 29~40% 처리구에서 가장 높은 광합성 능력과 엽록소 형광을 나타내, 내음성 수준이 공시수종 중에 가장 높음을 시사하였다.

• 한국환경생태학회지
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• 제19권2호
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• pp.188-192
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• 2005

이 연구는 큰 나무 아래 어린 나무를 심어 (수하식재) 새로운 숲을 가꾸는 방법 (임분갱신법)을 찾고자 낙엽송 간벌지에 음나무, 물푸레나무 및 층층나무 묘목을 1998년 봄에 수하식 재 한 것과 이웃에 위치 한 동일한 묘령의 임간포지에서 생육하는 개체들과의 엽록소항량과 광합성율을 2000년 7월에 측정$\cdot$비교하였다. 이는 식물종에 따른 광량에 대한 적응력 차이 (내음성)를 생리학적으로 확인하고자 시도하였다. 낮은 광도에 적응하기 위하여 음나무 잎은 다른 수종들에 비하여 보다 많은 엽록소함량과 광합성능을 증가시 키는 반응을 보였다고 판단된다. 이러한 결과로 보아 내음성은 음나무, 물푸레나무, 층층나무의 순으로 낮아지는 것이라 판단된다.

• 한국토양비료학회지
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• 제48권5호
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• pp.372-378
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• 2015

Growing crops under different soil textures may affect crop growth and yield because of soil N availability, soil N leaching, and plant N uptake. The objective of this study was to evaluate effects of three different soils (sandy loam, loam, and clay loam) on cucumber (Cucumis sativus L.) yield, nitrogen (N) use efficiency (NUE), and water use efficiency (WUE) by subsurface drip fertigation in the greenhouse. Three different soil textures are sandy loam, loam, and clay loam with 3 replications. The dimension of each lysimeter was $1.0m(W){\times}1.5m(L){\times}1.0m(H)$. Cucumber was transplanted on April $8^{th}$ and Aug $16^{th}$ in 2011. The subsurface drip line and tensiometer was installed at 30 and 20 cm soil depth, respectively. An irrigation with $100mg\;NL^{-1}$ concentration was automatically applied when the tensiometer reading was 10 kPa. Volumetric soil water content for cucumber cultivation was the highest in 30 cm soil depth regardless of soil texture and was lowered when soil depth was deeper. The volumetric soil water contents at soil depths of 10, 30, 50, and 70 cm were the highest at clay loam, followed by loam, and sandy loam. The growth of cucumber at the $50^{th}$ day after transplanting was the lowest at sandy loam. Cucumber fruit yields were similar for all three soil textures. The highest amount of water use at sandy loam was observed. Nitrogen and water use efficiencies for cucumber were higher for clay loam, followed by loam and sandy loam, while the amount of N leaching was the greatest under sandy loam, followed by loam, and clay loam. Overall, growing cucumber on either loam or clay loam is better than sandy loam if subsurface drip fertigation is used in the greenhouse.

• Journal of the Korean Wood Science and Technology
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• 제51권6호
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• pp.542-554
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• 2023

This study is a continuation of our previous work, which focused on the resistance of jabon wood to termites after impregnation with wood vinegar (WV) and animal-based adhesive (kak). This paper presents the physicomechanical properties of fast-growing jabon wood impregnated with kak at two concentrations (8% and 10%) in wood vinegar or water as a solvent with and without 4% borax. The physical properties of the impregnation solution, that is, viscosity, density, pH, and solid content, were evaluated according to SNI 06-4567-1998. Some physical parameters, such as weight percent gain (WPG), density, water uptake, anti-swelling efficiency (ASE), crystallinity, and mechanical properties, i.e., modulus of elasticity (MOE), modulus of rupture (MOR), and compression strength parallel to the grain (CS), of the impregnated wood were determined. Based on these results, wood impregnated using a mixture of kak in WV presented better physical (increased WPG, density, dimensional stability, and crystallinity) and mechanical (increased MOE/MOR and compression strength) properties than wood impregnated with a water solvent or untreated wood. The wood impregnated using WV and water solvent improved the physical and mechanical properties. The density of the wood increased by 44%-58% and 32%-47%, ASE radial-tangential increased by 38%-45%; 15%-28% after 24 h of water immersion, crystallinity increased by 59%-74%; 36%, MOE increased by 46%-57%; 28%-31%, MOR increased by 29%-34%; 14%-27%, and compression strength increased by 40%-76%; 38%-72% values to untreated wood.

• 한국환경과학회지
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• 제33권7호
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• pp.477-487
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• 2024

This study aimed to identify the growth environment of Cudrania tricuspidata by analyzing the site environment, soil characteristics, and vegetation structure of the species habitats and to provide basic data for identifying suitable cultivation sites for mass production. The study was conducted on 17 sites in five cities/counties of Gyeongnam and Jeonnam province. It was found that C. tricuspidata habitats were mainly distributed on gentle slopes in the southeast and southwest, with an average altitude of approximately 290 m. The soil of the C. tricuspidata habitats was sandy loam with a high proportion of sand, averaging 73.9%, 4.6%, and 21.5% sand, silt, and clay, respectively. The soil had a pH value of 5.41 (5.20-5.79), organic matter content of 8.2% (3.6-12.6%), total nitrogen content of 0.36% (0.19-0.54%), available phosphorus content of 3.50 ppm (0.95-7.61 ppm), and cation exchange capacity of 15.9 cmol⁺/kg (10.0-20.7 cmol⁺/kg) on average. The vegetation structure analysis showed that C. tricuspidata appeared in the tree layers of regions A (Jinju) and E (Yeosu), but the importance of C. tricuspidata was found to be high in the subtree and shrub layers in all regions. The ecological niche breadth was widest (0.874) in region B (Hadong) and narrowest (0.480) in region E (Yeosu).