• 해양환경안전학회지
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• 제26권2호
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• pp.175-185
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• 2020

본 연구는 부산시 기장군 연안의 춘계 해조 군집 특성을 파악하고자 수행하였다. 연구는 2017년 5월부터 6월까지 스쿠버 다이빙(scuba diving)을 이용하여 정량 및 정성 조사를 실시하였다. 연구 결과 녹조류 13종(10.7 %), 갈조류 18종(14.9 %), 홍조류 90종(74.4 %) 등 총 121종의 해조류가 출현하였고, 조간대에서 총 56종, 조하대에서 총 110종으로 조하대 출현종이 2배가량 많았으며, 해역별로는 문동 88종, 공수 76종, 대변 75종 순으로 높았다. 연구 해역의 평균 생물량은 1,501.5 g·m^-2로 확인되었으며, 조간대 1,133.5 g·m^-2, 조하대 1,869.4 g·m^-2로 조하대가 더 높았고, 해역별로는 문동 2,234.0 g·m^-2, 공수 1,228.1 g·m^-2, 대변 1,044.4 g·m^-2 순으로 높았다. 높은 생물량을 나타낸 종은 조간대에서 Ulva australis, Sargassum thunbergii, Corallina pilulifera, 조하대에서 Sargassum macrocarpum, Undaria pinnatifida, Phycodrys fimbriata로 확인되었다. 해조류 기능형군별 피도 비율에 따라 군집 상태를 분석한 결과 연구 해역 전체는 'Low', 집단별로는 'Low' ~ 'Moderate' 상태를 나타내었고, 이는 기회종(opportunistic species)이 기장 해역 전체에 걸쳐 폭넓게 분포하고 있는 것을 나타내기 때문에 교란이나 환경오염 등의 문제가 고려된다. 특히 기장 해역은 해조류 양식이 주를 이루고 있어 양식장 조성과 국가어항개발 및 연안 정비 등의 연안개발로 인한 인위적인 영향이 해조 군집에 지속적인 영향을 미칠 것으로 생각되며, 해역 전반에 걸친 해조 군집의 장기 모니터링과 우수한 해조 군집에 대한 관리 방안이 필요할 것으로 판단된다.

• 한국지반환경공학회 논문집
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• 제13권9호
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• pp.31-44
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• 2012

김해 딴섬 지역 지하수는 갈수기와 홍수기의 계절에 따른 지구화학 특성의 변화를 보인다. 농번기인 4월의 이온의 공간적 분포를 보면 $Fe^{2+}$, Fe(total), $Mn^{2+}$, $Ca^{2+}$, $Mg^{2+}$, $SiO_2$, ${HCO_3}^-$ 및 ${NO_3}^-$는 딴섬의 중앙부에서 높고 $Na^+$ 및 $K^+$는 딴섬 중앙부가 낮은값을 보이는데 높은 ${HCO_3}^-$ 및 ${NO_3}^-$는 딸기 재배용 비료에 의한 오염을 지시한다. 4월에 비하여 8월의 이온 농도의 지역별 편차가 적고 비료 등에 의한 인위적인 영향이 적어 강우에 의한 계절적 요인이 나타난다. 지하수의 수질 유형을 보면, 딴섬 중앙부는 함양 특성을 부분적으로 보이며 외곽부는 하천수와 상호 혼합되는 특성을 보여준다. Fe 및 Mn 이온 종에 대한 포화지수 계산결과, Fe의 광물종인 적철석, 침철석은 모두 과포화상태에 있어서 침전 가능한 상태이며, 능철석과 $Fe(OH)_3$, 일부는 불포화 상태로써 용존 이온상태로 존재할 가능성이 있다. Mn의 광물종인 능망간석은 불포화상태 및 과포화상태가 공존하며, 수망간석, 연망간석 및 수산화망 간석은 불포화상태로써 용존 이온 상태로 존재할 가능성이 크다.

• 농업과학연구
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• 제22권1호
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• pp.110-126
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• 1995

Korean economy has been developed successfully in the course of implementing the five year economic development plans since 1962. The gap of incomes and quality of life between rural and urban area has been widened and it made rural farm laborers drain to urban areas. Therefore the prevailing situation of labor shortage and wage hike in rural area has made farm management deteriorate in recent years. Under the internal and international unfavorable economic conditions, marginal farm land of 66.5 thousand ha has been idled as of end of 1993. The total area outside agricultural development zone with bad farming conditions including irrigation and drainage, and land consolidation for mechanization were estimated at 360.4thousand ha equivalent to 17.5% of the total farm land area in Korea. Considering the topographical conditions of marginal lands, the effective use of marginal lands should be studied from the view point of public interest rather than from the view point of individual economic conditions. Considering the present agricultural economic settings, such as price decrease, unfavourable benefits of farm products, labour shrotage, free trade of farm products and poor physical condition of marginal lands, the institutional and realistical measures for the effective utilization of idle and marginal land should be studied as soon as possible. Detail land use pattern should be surveyed in the areas outside agricultural development zone and have to be classified as orchard farms, grass land, fish culture farms, lawn and ornamental tree farm, sight seeing and leisure farms for urban peoples, special crops production farms and common farms to be developed for farm mechanization. According to the surveyed results, the expected utilization patterns of the idle and marginal lands could be considerd as village common use, farm land base development, leisure farm development, mutual complementary utilization between urban and rural areas, G't purchase and management, credit supply and new extension services, improvement of cropping patterns and sight seeing and leisure farm patterns. For the successful and reasonable management of the marginal lands, the actions such as institutional improvement, prohibition of idle marginal land, enforcement of activities of farm management committee members and land banking system of RDC including development and utilization systems should be included.

• 한국정보전자통신기술학회논문지
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• 제14권2호
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• pp.168-174
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• 2021

세계 농업 생산성 보고서에 따르면 현재 농업의 연평균 성장률은 1.63% 수준으로 2050년까지 증가하는 세계 인구 약 100억 명을 지원하기 위한 성장률 1.73% 보다 낮은 수준이며 이는 세계 농업의 생산성은 2050년까지 세계 인구의 식량, 사료, 바이오에너지 수요를 지속적으로 충족시킬 수 있을 만큼 증가하지 않고 있으며 미래의 식량난을 예고하고 있다. 본 연구는 농작물의 생산비용 감소, 생산량 증대, 품질 향상 등을 목적으로 국내 농가의 근권 환경 데이터 수집 후 데이터 분석을 통해 지역별 관수 제어 모델을 만들고 해당 지역에서 농사를 시작하는 농부들에게 조언을 줄 수 있는 모델을 제시하는 것을 목적으로 진행되었다. 본 연구에서 제시하는 관수제어 모델링은 시간의 흐름 및 기후에 따른 근권 환경 변화로 인한 배지무게·급액량·배액량의 변화를 그래프 모형으로 나타내는 것을 의미한다. 관수제어 모델링을 위해 근권 환경부 측정 장치를 통해 충정남도 논산, 부여, 예산 지역의 3~6월 근권환경 데이터 및 배지무게·급액량·배액량의 변화에 대한 데이터를 수집했으며 수집된 데이터를 통해 관수제어 모델도출을 위한 매개변수 설정하고 매개변수를 통해 시간의 흐름에 따른 무게·급액량·배액량의 변화를 확인 할 수 있는 관수제어 모델을 도출했다.

• Journal of Biosystems Engineering
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• 제10권1호
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• pp.1-12
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• 1985

The two agricultural zones, mid-and-northen region and southern region, were established according to the possibility of double cropping in the paddy field. For each agricultural zone typically mechanized farming systems with a power tiller for cultivating rice, barley and soybean were established. A computer program, which determines the optimum size of power tiller for the given farm size, the ratio of paddy area to total area and the ratio of double cropping area to the paddy area, was developed. The computer program was executed for the farm sizes, 1 to 3 ha, and the ratios of paddy area to the total area, 60~80%, and the ratio of double cropping area to the total paddy area, 70%. The following conclusions were drawn from analyzing the computer outputs. 1. In the mid-and-northern region, a smaller power tiller (5 or 6 PS) appeared to be more economical for the farm size up to 3 ha. From the viewpoint of fuel consumption a 6 PS power tiller appeared to be more favorable. 2. In the southern region, a smaller tiller (5 or 6 PS) appeared to be more economical for the farm size up to 1.5 ha. But, a larger power tiller (8 or 10 PS) appeared to become more economical as the farm size and the barley planted area increased. 3. For the southern region where rotary tilling is heavily required due to double cropping, it is recommended to develop a power tiller which weighs light like the conventional 5 or 6 PS small power tiller but has lager power.

• 농업과학연구
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• 제43권4호
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• pp.537-546
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• 2016

The development of models for agriculture systems, especially for crop production, has supported the prediction of crop yields under various environmental change scenarios and the selection of better crop species or cultivar. Crop models could be used as tools for supporting reasonable nutrient management approaches for agricultural land. This paper outlines the simplified structure of main crop models (crop growth model, crop-soil model, and crop-soil-environment model) frequently used in agricultural systems and shows diverse application of their simulated results. Crop growth models such as LINTUL, SUCROS, could provide simulated data for daily growth, potential production, and photosynthesis assimilate partitioning to various organs with different physiological stages, and for evaluating crop nutrient demand. Crop-Soil models (DSSAT, APSIM, WOFOST, QUEFTS) simulate growth, development, and yields of crops; soil processes describing nutrient uptake from root zone; and soil nutrient supply capability, e.g., mineralization/decomposition of soil organic matter. The crop model built for the DSSAT family software has limitations in spatial variability due to its simulation mechanism based on a single homogeneous field unit. To introduce well-performing crop models, the potential applications for crop-soil-environment models such as DSSAT, APSIM, or even a newly designed model, should first be compared. The parameterization of various crops under different cultivation conditions like those of intensive farming systems common in Korea, shortened crop growth period, should be considered as well as various resource inputs.

• 한국환경복원기술학회지
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• 제11권2호
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• pp.75-86
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• 2008

The wetlands have functions those were retention of diverse biota, purification of water quality, control of climate and flood, eco-tourism and supply of agricultural water, and that was the ecosystem of high biodiversity as the zone of transition between inland and water. Therefore, this study showed the conservation and management plan by analyzing in the abiotic and biotic environment of forest swamp, Gyeongsangbuk-do. The results were as follows. Examining the management plan of the abiotic environment, there will need to establish the hydrological plan in continuous expediting the supply of water to maintain a humid soil of swamp, and to try to find the organic farming, use of low toxic agrichemicals and so on to prevent occurring a non-point source pollutants. To prevent changing the flowing of ground water and inflow of earth and sand in modifying the land character, there will be needed to restrict the construction of farmland and slope around swamp. To manage the biotic environment, there needed to offer the habitat by removing the regular interval and individual of a dead tree, and to improve the growth environment of vegetation. Because the naturalized plants disturb the natural vegetation, they will be removed. The afforested trees like Robinia pseudoacacia and Amorpha truticosa will be renewed to prevent the heterogeneity of landscape ecology, and the active conservation plan on wetland species will be established. As this study was carried out to study on the partial swamp, Gyeongsanbuk-do, the ecological environments distributing a swamp in Korea show a some problem. In the future, the study will accomplish to study the accurately and objectively ecological environment and management of a swamp by analyzing the extensive sites.

• 한국수산과학회지
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• 제46권6호
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• pp.886-891
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• 2013

We analyzed surface sediments to explain the substrate characteristics of sea cucumber Stichopus japonicus habitat. The analyses included grain-size determination, water content (WC), loss on ignition (IL), chemical oxygen demand (COD), and acid volatile sulfide (AVS) content. We obtained data on sea cucumber density, weight, and length at each station in a marine farming area in the middle of Korea's Taean coast on the West (Yellow) Sea in May, 2012. The apparent density of S. japonicus was high in coarse and bimodal sediments, whereas it was low in fine and unimodal sediments. The mass of S. japonicus was greater in fine than in coarse sediments, showing a different trend from sea cucumber density. The values for WC, IL, COD, and AVS in surface sediments were higher in areas with high densities of S. japonicus than in areas with low sea cucumber densities. In particular, the concentration of AVS was much higher than the value proposed in Japanese criteria for areas with high S. japonicus density.

• 대한기계학회논문집B
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• 제26권11호
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• pp.1622-1629
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• 2002

To enhance isothermal characteristics of glass-farming surface, a rectangular parallelepiped heat pipes was fabricated, tested, and analyzed. The working fluid was sodium and the wall material was stainless steel 304. The dimension of the heat pipe was 210 (L) $\times$ 140(W) $\times$ 92(H)mm. A lattice structure covered with screen mesh was inserted to promote return of working fluid. The bottom side of heat pipe was heated electrically and the top side was cooled by liquid circulation. The temperature distribution at the bottom surface was of major concern and was monitored to determine isothermal characteristics. A frozen start-up of rectangular parallelepiped liquid metal heat pipe was tested. The operating mode of the sodium heat pipe was affected by the temperature of cooling zone, input heat flux, and the operating temperature of heat pipe. The heat pipe operated in a normal fashion as long as the heat flux was over 5.78W/cm$^2$, and the inside wall temperature of condenser part was above 95$^{\circ}C$ The maximum temperature difference at the bottom surface was observed to be 32$^{\circ}C$ when the operating temperature of the heat pipe was operating normally around 50$0^{\circ}C$. The result showed that a sodium heat pipe was very effective in reducing significantly the temperature difference in the glass-forming surface.

• Ocean and Polar Research
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• 제25권3호
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• pp.331-345
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• 2003

The fishing ground surrounding Wangdol-cho is not only overexploited by the littering of dilapidated fishing net and equipment, but also by fishermen's overfishing, surpassing optimum fisheries resources. In addition, increasing fishing efforts (number of fishing vessel and fishing net, etc) contribute to the deterioration of fishing ground, and it is urgently required that schemes to tackle the problems should be taken. To effectively address the problems as such, this paper aims to propose sustainable utilization and management scheme of fishing ground through classification of fishing ground surrounding Wangdol-cho as one area which is less than 50m deep, measuring $13.66km^2$ and the other, permission fishing area of Gill Net fishery, measuring $347.23km^2$. The analysis shows that, for the water area less than 50m deep, implementation from a short-term perspective includes autonomous management fishery by gill net and trap fishery. For the permission fishing area of Gill Net fishery, implementation includes limit on fishing period, real name system of fishing equipment and limit on fishing equipment. Implementation from a medium and long-term perspective includes limit on scuba diving, designation of underwater sightseeing zone, sea farming, facilities of surveillance, adoption of approval system for the permission fishing area of Gill Net fishery and introduction of report system for fishing.