• Journal of Wetlands Research
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• v.19 no.4
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• pp.533-541
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• 2017

Agricultural landscape has many ecosystem service functions. However, the development of the horticulture complex has no consideration for environmental conservation. Therefore, we analyzed the priorities of ecosystem service functions required for the composition. The study was conducted in three stages. As a result of the first survey, 17 functions were selected to be improved. In the second survey, 12 functions were selected excluding 5 functions. Finally, 1. Measures for water purification, 2. Groundwater recharge plan, 3. Surface water storage space, 4. Flood control measures, 5. Vegetation diversity space, 6. Carbon emission reduction plan, 7. Aquatic insect habitat space, 8. Amphibian reptiles 9. Landscape and Waste Management, 10. Bird Species Space, 11. Heat Island Mitigation Plan, 12. Experience / Ecological Education Plan. We proposed the structure, capacity, flow rate, arrangement and form of the water treatment facility to improve water quality by improving the function. We proposed a reservoir space of 7-10% for groundwater recharge. The development of reservoir and storage facilities suitable for the Korean situation is suggested for the surface water storage and flood control measures. And proposed to secure a green space for the climate cycle. Proposed habitat and nutrient discharge management for biodiversity. We propose green area development and wetland development to improve the landscape, and put into the facilities for experiential education. The results of the research can be utilized for the development and improvement of the horticultural complex.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.1
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• pp.1-10
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• 2010

A regional climate model (RCM) can be a powerful tool to enhance spatial resolution of climate and weather information (IPCC, 2001). In this study we conducted dynamical downscaling using Weather Research and Forecasting Model (WRF) as a RCM in order to obtain high resolution regional agroclimate indices over the Korean Peninsula. For the purpose of obtaining detailed high resolution agroclimate indices, we first reproduced regional weather for the period of March to June, 2002-2008 with dynamic downscaling method under given lateral boundary conditions from NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis data. Normally, numerical model results have shown biases against observational results due to the uncertainties in the modelis initial conditions, physical parameterizations and our physical understanding on nature. Hence in this study, by employing a statistical method, the systematic bias in the modelis results was estimated and corrected for better reproduction of climate on high resolution. As a result of the correction, the systematic bias of the model was properly corrected and the overall spatial patterns in the simulation were well reproduced, resulting in more fine-resolution climatic structures. Based on these results, the fine-resolution agro-climate indices were estimated and presented. Compared with the indices derived from observation, the simulated indices reproduced the major and detailed spatial distributions. Our research shows a possibility to simulate regional climate on high resolution and agro-climate indices by using a proper downscaling method with a dynamical weather forecast model and a statistical correction method to minimize the model bias.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.928-932
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• 2006

지금까지의 수자원계획평가는 유역별 권역별로 이루어져 왔다. 다시 말해 지역적인 수자원계획평가는 제대로 이루어지지 않았다고 할 수 있다. 한 지역의 수자원계획평가를 하기 위해서는 그 지역의 물이용 순환시스템을 분석해야 하며, 이를 통해 유역의 기본 자료를 제공할 수 있을 뿐만 아니라 순환구조 및 현황 문제점 파악, 시스템 개선 등을 수행할 수 있다. 하지만 국내에서는 아직까지 종합적으로 물순환 및 물이용에 대해 제시된 연구결과는 거의 없으며, 각 순환요소에 대한 개별적인 연구가 수행된 경우가 있다. 도시용수의 순환시스템의 경우 전체적인 순환시스템에 대한 연구보다는 주거형태에 따른 회귀율의 산정과 같은 특정 분야에 대한 연구결과가 제시된 경우가 있으며, 농업용수에 대해서도 회귀율의 추정과 같은 연구가 제시되어 있는 정도로 관련 연구의 수행이 매우 미흡한 실정이다. 본 연구에서는 서산 지역의 물이용 순환시스템을 조사하여 분석함으로써 기 수립된 서산 지역의 장래 계획들의 타당성을 검증하고, 이에 대한 대책 및 문제점을 제시하고자 하며 장래에 일어날 수 있는 수량 및 수질 변화에 대한 상황들을 시나리오로 개발하여 분석함으로써 장래에 대한 수량, 수질을 연계한 수자원계획을 수립하고자 한다. 또한, 서산 지역의 대표적인 수원인 보령댐의 댐운영 및 가뭄 모니터링에 이용할 수 있도록 보령댐에 대한 가뭄지수(물공급능력지수, 표준물공급능력지수)를 분석하여 제시하고자 한다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.109-119
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• 2018

The purpose of this study is to evaluate the structural safety of the front-end loader for the 90 kW class of agricultural tractors in impact test conditions. Deformation and stress on the loader under the impact test conditions are analyzed using the commercial finite element analysis software ANSYS. In previous research dealing with the initial design of the loader, the maximum stress occurred in the mount and exceeded the yield strength of the material. In this paper, an improved design of the mount of the loader was proposed to reduce the stress concentration in the initial design. The safety of the improved design was verified by performing rigid-body dynamics analysis, transient structural analysis, and static structural analysis under three impact test conditions: a drop and catch test, a corner pull test, a corner push test. It was found that the local stress concentration in the mount that appeared in the initial design was greatly reduced in the improved design, and that the maximum stresses occurred in the three impact test conditions are smaller than the yield strength. It is expected that the design improvement of the mount proposed in this study and the method of analysis may be effectively used to enhance structural safety in the development of new model front loaders in the future.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.939-965
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• 2014

Farm succession in the next generation has profound implications for the future structure of the agricultural industry and the procurement of agricultural human resources. Therefore, this study sought to suggest the policy directions for farm succession through investigating the foreign policies and comparing it with Korean policies. The followings were derived from the comparison analysis. First, support is required in establishing master plans for farm succession from operators to successors. Second, it is needed to develop and disseminate effective model for farm succession. Third, an assistance policy for farm households without successors should be initiated. Fourth, the fragmentation of farmland ownership should be counteracted.

• Journal of Biosystems Engineering
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• v.22 no.1
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• pp.21-29
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• 1997

왕겨 재를 분쇄하여 콘크리트 混和용 재료로 이용하려는 연구의 일환으煙로서, 파이로트 規模의 多目的 왕겨 燒却爐를 設計, 裂作하고 그 性能을 分析하였다. 왕겨 燃燒時의 熱에너지는 回收하여 원예施設의 煖房이나 콘크리트의 高溫 養生水로써 이용하고자 熱交煥裝置를 제작하여 왕겨 燒각爐시스템에 장착하였고, 排煙가스내의 이산화탄소가 시설원예 作物의 光合成에 이용될 수 있는지 排煙가스의 造成을 조사하였다. 분쇄된 왕겨 재의 큰크리트 混和材로서의 적합성은, 燃燒 灰分의 성분 중 $SiO_2$ 의 結晶化 상태를 分析함으로써 判斷하였다. 연구결과를 要約하면 다음과 같다. 1. 왕겨 灰分의$SiO_2$ 結晶化는 燃燒온도 $750^circ C$ 이하에서는 거의 발생하지 않는 것으로 분석되었다. 2. 燒却爐의 작동은 매우 만족스러웠으며 最適 작동조건은 왕겨供給率 15kg/h. 制御온도 $600^{\circ}C$로 分析되었다. 最適 작동조건에서, 왕겨燃燒率은 97%, 熱交換機 效率은 59.5%, 전체 시스템의 熱效率은 57.7%로서 양호하였으며, 灰分의 $SiO_2$ 結晶化도 거의 발생하지 않아 生成된 왕겨 灰分은 훌륭한 큰크리트 混和在로 판단 되었다. 3. 燒却爐내 溫度分布는 대체로 均一하였으며, 排煙가스내의 大氣오염물질 중, 질소酸化物과 황酸化物 함량은 許容기준치보다 매우 낮았으나 일산화탄소 함량은 許容기준값 부근으로 나타나 排煙가스를 직접 원예시설 내에 공급하기 위해서는 약간의 연소실 구조 개선이 필요하다고 판단되었다.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.248-254
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• 2015

There has been no previous study on technology development of large capacity drainage pump for rescue sinking ship in the country. The agricultural drainage pump was widely used for rescue sinking ship but this pump has several problems such as efficiency, low displacement and malfunction in winter. Therefore, this paper proposes to solve the problems for swiftly rescue sinking ship and develops the drainage pump system that has $20m^3/min$ mass flow rate specification at suction head 8 m. The centrifugal pump type the most commonly used in the field of naval architecture and ocean engineering was selected and designed based on the requirement specification. The blade design of impeller was derived from the Stepanoff coefficient and requirement specification and used computational fluid dynamics to review the target mass flow rate according to the impeller RPM at design operating conditions. We also performed structure analysis of the impeller to find structurally vulnerable points for the pump in service and completed the theoretical design of drainage pump system.

• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.274-282
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• 2019

In recent years, big data analysis has been expanded to include automatic control through reinforcement learning as well as prediction through modeling. Research on the utilization of image data is actively carried out in various industrial fields such as chemical, manufacturing, agriculture, and bio-industry. In this paper, we applied NASNet, which is an AutoML reinforced learning algorithm, to DeepU-Net neural network that modified U-Net to improve image semantic segmentation performance. We used BRATS2015 MRI data for performance verification. Simulation results show that DeepU-Net has more performance than the U-Net neural network. In order to improve the image segmentation performance, remove dropouts that are typically applied to neural networks, when the number of kernels and filters obtained through reinforcement learning in DeepU-Net was selected as a hyperparameter of neural network. The results show that the training accuracy is 0.5% and the verification accuracy is 0.3% better than DeepU-Net. The results of this study can be applied to various fields such as MRI brain imaging diagnosis, thermal imaging camera abnormality diagnosis, Nondestructive inspection diagnosis, chemical leakage monitoring, and monitoring forest fire through CCTV.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.81-97
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• 1987

Two nozzles with different size (Figure 2) were particularly designed to supply air through the swirl core into the central part of the liquid stream in the same parallel direction to produce a well-mixed air and water in the whirl chamber as spray liquid in bubble formation. Atomization was attempted to improve by using both the preliminary break-up process with less viscosity and less surface tension in the whirl chamber and the effects of increased frequency of the band of drops with the raised ambient air density in front of the nozzle orifice. The volumetric ratio between spray liquid and air on four levels was used to investigate the effects of air as a component of the mixture on atomization. The results of the experiment were summarized as follows; Droplet size became progressively finer as the operating pressure was increased in the range of $0.70kg/cm^2$ to $6.33kg/cm^2$, which was similar to the previous works. The new atomizing mechanism so-called 'air-center nozzle' gave a narrower range in droplet size distribution with smaller volumetric median diameter (VMD) than that of the existing spray system at a given pressure, which showed the possibility of improvement of atomization in a certain limit. The volumetric median diameter produced by the new atomizing mechanism was decreased from the central region toward the exterior edges across the spray pattern.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5051-5059
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• 2015

Structural behaviour of the front loader for an agricultural tractor was analyzed for three impact test conditions: drop and catch, corner pull, and corner push. Rigid-body dynamic, transient structural, and static structural analyses were conducted using a commercial finite element software. Analysis of the drop and catch test dealt with the case that the bucket located at the maximum elevation was dropped and catched through three steps. Analysis of the corner pull test dealt with the case that the bucket constrained to the ground by a chain at its corner was raised suddenly. Analysis of the corner push test dealt with the case that the corner of the bucket collided with an obstacle. Results of analyses of the three test conditions showed that maximum stress occurs at the geometrically discontinuous location in the mount and is caused from local stress concentration. Results of the present research can be utilized as a guideline to achieve more reliable and safe structural design of the front loaders.