• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.629-639
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• 2018

In this study, the application of the single beam echosounder and multi beam echosounder was analyzed for the Youngsan river, from the Juksanbo to the Juksan bridge, length of 840m, width 230m and area $0.16km^2$. A single beam echosounder and a multi beam echosounder are mounted on an USV (Unmanned Surface Vessel), and each data is acquired. Then, TIN (Triangular Irregular Network) is created and the grid depth of 10m intervals is extracted. The grid depth of the single beam echo sounder and the grid depth of the multi beam echo sounder were overlapped to compare the two data. As a result of analysis using 5,024 data, the mean depth difference was 0.0319m and the standard deviation was 2.4095m. The river bed shape was similar to each other. If the multi-beam echo sounder is regarded as the standard, the volume difference of the stream is $161,882m^3$. With a multi-beam echo sounder installed, the operating distance increased by approximately 55% to 4595.85m, and the operating time increased by approximately 59% to approximately 47%.

• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.2
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• pp.32-40
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• 1989

Dynamic ship positioning(DP) system is used to keep the position and heading of a ship, or a floating platform, above a pre-selected site on the seabed by using thrusters. This paper presents a control system based on filtering technique and optimal control theory. The planar motions of a vessel are assumed to consist of low frequency(LF) component and high frequency(HF) one. The former is mainly due to thrusters, current, wind and second order wave forces, while the latter is mainly due to first order oscillatory component of the wave force. Furthermore position measurement signals include the noise. By means of self-tuning filter and Kalman filter techniques, LF motion estimates and HF ones are seperately achieved from the position measurements of the vessel. The estimated LF motions are used as input to the feedback loops. The total thruster power is minimized using the Linear Quadratic Gaussian control theory. The performance of the vessel with the DP system is investigated by computer simulation.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.102-109
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• 2011

This research was conducted to establish efficient methods to control root-zone temperature of tomato plant when cultivated in perlite bag during the summer season. Tomato plants were grown with four selected treatments; covering irrigation pipe by aluminum insulation material (Insulate), discarding nutrient solution inside the irrigation line before each irrigation (Discard), skipping irrigation for two hours from 13:00 to 15:00 (Skip), or no treatment as a control (Non). Based on the analysis of plant development index, all plants with selected treatments grew more vigorous and vegetative in similar growth patterns. The discard treatment exhibited the best root-zone temperature control among the treatments. The discard treatment also resulted in the best root growth and above-ground growth, followed by skip, Insulate and Non. The total yields were obtained by the order of Insulate, Discard, Non and Skip. However the marketable yield was obtained by the order of Discard, Insulate, Skip and Non. The net incomes treated with Discard and Insulate were 9,687,600 and 9,396,000 Korean won per hectare, respectively, exhibiting higher incomes than that of Non. Therefore, it was concluded that insulation of the irrigation pipe and discarding nutrient solution inside the pipe before each irrigation were the most desirable and economical methods in terms of costs and yields.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.539-547
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• 2002

본 연구는 풋콩 탈협기 개발을 위한 기초연구로서 풋콩 탈협기의 급치를 교환할 수 있고, 급동의 주속도와 송풍팬의 회전속도 및 공기 흡입구의 개구면적을 조절할 수 있는 실험장치를 제작하고, 급치의 종류가 풋콩의 탈협 및 손상에 미치는 영향을 분석하였다. 또한 송풍팬의 회전속도와 흡입 공기구의 개구비 변화 따른 선별 성능을 분석하였다. 그 결과를 요약하면 다음과 같다. 1 급치의 종류에 따른 풋콩의 미 탈협율은 철선 급치가 최대 1.6%, 최소 0.0%,평균 0.7%로서 가장 낮게 나타났고, 그 다음이 경도 60의 고무제 급치로서 최대 2.0%, 최소 0.0% 평균 1.1%, 경도 80의 고무제 급치는 최대 2.5%, 최소 0.0% 평균 1.7% 순으로 높아졌다. 또한 풋콩의 미탈협율은 급동 원주속도가 18m/s에서 55m/s로 증가할수록 감소하였다. 이는 급동의 원주 속도가 증가함에 따라 급치의 선단이 풋콩 꼬투리에 가하는 타격력이 증가하기 때문인 것으로 생각된다. 2. 급치의 종류에 따른 풋콩의 손상율은 경도 80의 고무제 급치는 최대 5.2%, 최소 1.3%, 평균 2.8%로서 가장 낮게 나타났고, 그 다음이 경도 60의 고무제 급치로서 최대 5.7%, 최소 2.4% 평균 3.8%, 철선 급치는 최대 6.3%, 최소 2.6% 평균 4.2% 순으로 높아졌다. 또한 풋콩의 손상율은 급동 원주속도가 증가할수록 풋콩 꼬투리의 손상율은 증가하였다. 이 또한 급등의 원주 속도가 증가함에 따라 급치의 선단이 풋콩 꼬투리에 가하는 타격력이 증가하기 때문인 것으로 생각된다. 3. 공기흡입구의 개구면적을 증가시킬수록 선별율은 높게 나타났으나 개구비가 60%이상에서는 선별율이 크게 차이가 나지 않았으며, 송풍팬의 원주속도를 높일수록 선별율은 높게 나타났다.도 콤바인이 직선구간 및 선회구간을 주행하며 수확작업이 가능함을 알 수 있었다. 그러나 곡선구간에서는 최대오차가 65.5 cm로 매우 크게 나타나, 콤바인을 무인 자율주행으로 수확하기에는 어려움이 있는 것으로 나타났다. 실제 포장은 이론적인 완전한 직선보다는 작은 굴곡이 있는 곡선의 형태가 이루어져 있으므로 주행 오차를 감소하기 위해서는 기계시각을 이용하면 보다 정밀한 조향을 이룰 수 있을 것으로 예상된다. 포장에서 DGPS 신호, 자이로 센서 등을 이용한 콤바인의 무인주행 장치는 무인 수확작업을 위한 가능성을 보여주었고, 일부의 센서의 기능을 개선하면 만족한 성능을 나타낼 수 있을 것으로 판단된다.dislocations form local defect arrangements at the grooves permitting the substantial reduction in defect density over the remainder of the interfacial area.한 최대의 감자 재배지역을 형성하였다. 제주도는 산지지형과 따뜻한 기온으로 2기작이 가능하고, 감자가공 공장설립과 교통발달에 따른 육지 시장과의 접근이 용이해졌기 때문에 남한에서 2번째로 큰 감자재배지역이 되었다.(요약 및 결론에서 발췌)그람양성균에서 효과적이었으며, 농도별 항균력시험 결과 농도가 증가할수록 비례하여 저해율도 증가함을 알 수 있었다. 첨가농도를 달리하여 미생물의 생육도를 측정한 결과, fraction II磎꼭\ulcorner경우 그람양성균에 대해 500 ppm 이상에서 뚜렷한 증식억제효과를 나타내었다.서 뚜렷한 증식억제효과를 나타내었다.min/+}$계 수컷 이형접합체 형질전환 마우스에 AIN-76A 정제사료만을 투여한 대조군은 1.40$\pm$

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.905-923
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• 2018

In order to generate high-resolution products using UAV images, it is necessary to analyze the sharpness of the themselves measured through image analysis. When images that have unclear sharpness of UAV are used in the production, they can have a great influence on operations such as acquisition and mapping of accurate three-dimensional information using UAV. GRD (Ground Resolved Distance) has been used as an indicator of image clarity. GRD is defined as the minimum distance between two identifiable objects in an image and is used as a concept against the GSD (Ground Sampling Distance), which is a spatial sample interval. In this study, GRD is extracted by analyzing the edge target without visual analysis. In particular, GRD to GSD ratio (GRD/GSD), or GRD expressed in pixels, is used as an index for evaluation the relative image sharpness. In this paper, GRD is calculated by analyzing edge targets at various altitudes in various shooting environments using a rotary wing. Using GRD/GSD, it was possible to identify images whose sharpness was significantly lowered, and the appropriateness of the image as an image clarity index was confirmed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.527-534
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• 2017

The purpose of this study is to develop unmanned equipment that can automatically move to the desired point and measure water quality at the correct depth. For this purpose, we constructed a water sampling lift and water sampling container, an unmanned vessel equipped with a VRS-GPS, an acoustic echo sounder, and a water quality sensor. Also, we developed an automatic navigation algorithm and program, an automatic water sampling program, and a water quality map generation program. As a result of the experiment in the detention pond, the unmanned vessel sailed along the planned route with an accuracy of about 93% within the error range of 3m. In addition, the water quality sensor installed in the lift was able to acquire the water quality of the target area in real time and transmit it to the server via wireless Internet, and it was possible to monitor the water quality of each site in real time. Through field experiments, the water sampling lift was able to control the desired length with an accuracy of about 94%. The stretch length accuracy experiment of the water sampling lift was impossible to measure directly in the water, so it was replaced land-based experiment. We also found some unstable problems due to the weight of the water sampling lift and the weight of the air compressor to operate the water container. Except these two problems, we accomplished purpose of this study. An automated water quality measurement method using an unmanned vessel can be used to measure the quality of water in a difficult to access area and to secure the safety of the worker.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.54-59
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• 2002

1. 일시수확형 고추의 기계수확 요인을 구명하기 위하여 4종류의 탈과장치를 제작하여 공시고추로 탈과시험을 실시한 결과 탈과장치는 방사대칭식(브러쉬형), 고추이송(공급)속도는 0.1m/s, 탈과장치 간격은 3cm, 탈과장치 회전수는 180rpm에서 정상탈과율 77.3%, 손상률 7.6% 미탈과율 3.0%로 가장 양호한 성적이 나타났다. 2. 방사대칭식(브러쉬형) 탈과장치를 이용하여 무지용 상향착과형 고추, 지주용 하향착과형 고추, 지주용 상향착과형 고추를 공시하여 고추별 탈과시험을 실시한 결과, 고추이송(공급)속도 0.1m/s, 원통사이간격 3cm, 탈과장치 회전수 180rpm에서 가장 양호한 성적이 나왔으며, 지주용 하향착과형 고추가 정상탈과률 82.7%, 손상률 7.4%, 미탈과율 2.7%로 무지주용 상향착과형 고추(52.3%, 14.3%, 12.5%)와 지주용 상향착과형 고추(77.3%, 7.6%. 3.0%)에 비해 기계수확에 적합한 것으로 나타났다. 3. 이상의 고추 기계수확 요인시험의 결과, 탈과장치는 방사대칭식(브러쉬형) 고추종류로는 하향착과형 고추가 기계수확에 바람직한 것으로 나타났으며, 수확 후 회수가 가능한 줄기부착고추를 포함한다면 고추기계수확률은 80% 이상, 꼭지가 떨어진 것이 대부분인 손상고추도 수확 후 즉시 기계건조하여 가공용으로 사용한다고 가정한다면 기계 수확률은 90% 이상 가능하지만, 이것의 수용 여부는 좀 더 폭넓은 의견수렴 및 조사가 필요하다고 사료된다. 4. 고추수확 기계화를 위해서는 실내요인 시험 결과를 토대로 포장에서 수확메커니즘 구명과 더불어 고추 과실이 크고 무지주용 하향착과형 일시수확형 고추 품종의 개발이 병행되어야 한다고 판단된다. 5) 마늘 선별작업 -마늘선별기는 작업성능이 높고 5등급으로 균일 선별되었으며 손상도 없었으나, 기계가 크고 무거워 이동이 곤란하고 가격이 비싸므로 선별등급을 3∼4단계로 줄이고 소형 농가보급형으로 개량제작이 요구됨. 나. 마늘재배 일관기계화에 의한 노동투하시간과 비용 -종자준비부터 통마늘선별까지의 일관기계화로 투입된 주요작업의 노력은 75∼76%가 절감되고, 재배규모 3ha기준시 비용은 44-53%절감되었음. the annealing texture. Observations by TEM and EBSD revealed the formation of very fine grains of ∼1.0$\mu\textrm{m}$ after CCSS.he dislocations form local defect arrangements at the grooves permitting the substantial reduction in defect density over the remainder of the interfacial area.한 최대의 감자 재배지역을 형성하였다. 제주도는 산지지형과 따뜻한 기온으로 2기작이 가능하고, 감자가공 공장설립과 교통발달에 따른 육지 시장과의 접근이 용이해졌기 때문에 남한에서 2번째로 큰 감자재배지역이 되었다.(요약 및 결론에서 발췌)그람양성균에서 효과적이었으며, 농도별 항균력시험 결과 농도가 증가할수록 비례하여 저해율도 증가함을 알 수 있었다. 첨가농도를 달리하여 미생물의 생육도를 측정한 결과, fraction II磎꼭\ulcorner경우 그람양성균에 대해 500 ppm 이상에서 뚜렷한 증식억제효과를 나타내었다.서 뚜렷한 증식억제효과를 나타내었다.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.451-458
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• 2012

In this paper, the design study of a new convertible six d.o.f underwater robot which can be a ROV or AUV according to underwater work purpose is presented. A structure design about the ROV and the AUV and its design on the control system is presented. In case of the AUV, an analysis on thruster forces in accordance with operating speed has been performed. A sensor fusion board which can proceed various sensor signals to identify correct positions and speeds has been developed and a total control system including EKF(Extended Kalman Filter) has been designed and developed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1330-1341
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• 1993

The kinematic synthesis deals with the systematic design of mechanisms for a given performance. The area of synthesis may be grouped into two categories to determine the type and to size the dimensions of a mechanism for a specified task. In this paper, using a database of mechanisms a designer can determine the type of mechanism conveniently and design equations are automatically generated for a given input performance. The solving method of design equations utilizes an optimization routine to obtain roots effectively. The linkages of 4, 6, and 8bars with revolute joints are considered in this study but may be extended to linkages of more bars.

• 전자공학회논문지 IE
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• v.46 no.4
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• pp.25-30
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• 2009

The cooling water circulation pipes had been used to drop the temperature of refractory outside shell of blast furnace by cooling plate or stave type. They were attacked by surrounding CO gas and it was the cause that they were corroded and the water inflow in the refractory due to leakage of water. So, the life of refractory material was shorten and changed for the worse the conditions of blast furnace. The automatic sensing device for water leakage of cooling pipe was developed to check the position of trouble by use the micro-process system when cooling water leak and then CO gas will be inflowed into the cooling pipe at the leakage position. The inflowed CO gas will be detected in the micro-process system and delivered the detected position of cooling plate or stave to main control room through the wireless-radio relay station. This system can be possible to detect the position of cooling plate or stave the water leakage part immediately and then deliver the signal to main control room by use the micro-process system and wireless-radio relay station. This system will develop the working condition from manual system to unmanned auto alarm system.