• 농업과학연구
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• 제46권4호
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• pp.781-790
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• 2019

Changes in the physical and chemical properties of soil materials during the nursing process have a great influence on the quality of containerized seedlings and on growth and survival after planting. In this study, the effect of biomaterials and their mixed ratios on the growth of Zelkova serrata seedlings in a containerized seedling production system was investigated. Mushroom sawdust, pine bark, and carbonized rice husk were used as biomaterials. The mixed ratios were 10% and 20% volume ratio of the growing medium volume, including the untreated controls. There was no significant difference in the height growth of the Zelkova serrata seedlings according to the biomaterials. The root collar diameter was the highest with the 20% carbonized rice husk and the lowest with the mushroom sawdust. The difference between the highest quality index and the lowest quality index was 30% in the order of the carbonized rice husk, pine bark, control, and mushroom sawdust, but there was no statistical significance. In this study, if the growing medium mixed with biomaterials does not reduce the seedling growth compared with the control, it is considered that the biomaterial can replace a part of the growing media. Therefore, the results show that some of the growing media can be replaced with carbonized rice husk or pine bark when producing Zelkova serrata seedlings.

• Journal of Plant Biotechnology
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• 제43권2호
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• pp.240-247
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• 2016

In this study, routinely used transformation method, which includes transferring explants onto co-cultivation medium after inoculating them with bacterial solution for a while, was compared with 3 different inoculation methods. In every 3 methods, hypocotyl explants excised from 7-day-old sterile flax seedlings having cotyledon leaves and no root system dried under air flow in sterile cabin for 35 min were inoculated with different volumes of bacterial solution at different inoculation periods. GV2260 line of Agrobacterium tumefaciens having 'pBIN 19' plasmid containing npt II (neomycin phosphotransferase II) gene and GUS reporter gene was used in transformation studies. After inoculation, hypocotyl segments of seedlings (0.5 cm in length) - were excised and left to co-cultivation for 2 days. Then, explants were transferred to regeneration medium supplemented with different antibiotics. The presence of npt-II and GUS genes in transformants was confirmed by PCR and GUS analysis. The highest results in all characters examined in all cultivars were obtained from the 2 inoculation method in which hypocotyls excised from seedlings inoculated with $500{\mu}l$ of bacterial solution after drying in sterile cabin for 35 min were used.

• Ecology and Resilient Infrastructure
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• 제3권2호
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• pp.92-99
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• 2016

본 연구는 최근 많은 관심을 받고 있는 그린인프라 및 저영향개발 (GI & LID) 기술에 대한 물순환 및 물환경 효율성 측정을 위한 실내 외 검증, 인증 시스템을 개발하였다. 기술의 검증 및 인증을 위한 실외시험시설은 건축형, 도로형, 주차장형, 빗물정원형, 생태공원형 등 크게 5구역으로 나누어 기술종류에 따라 시험이 가능하도록 시스템을 개발하였다. 또한, 실내실험으로는 수리/수문분야, 토질/지반분야, 환경분야 등 다양한 시험이 가능하도록 시험장비의 개발 및 구축을 하였다. 본 연구에서 개발한 GI & LID 검 인증시스템 구축을 위한 실내 및 실외 시험시설의 개발은 GI & LID 기술의 적용을 위한 객관적이고 신뢰성 있는 데이터 제공에 대한 기반을 마련함과 동시에 관련 사업의 활성화에 기여할 것으로 판단된다.

• Geomechanics and Engineering
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• 제23권1호
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• pp.85-92
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• 2020

This study adopted soil test and laboratory physical model experiments to simulate the tailings impoundment accumulation process according to the principle of similarity. Relying on the practical engineering, it analyzed the tailings deposition characteristics on dry beach surface during the damming process, as well as the variation rules of dam saturation line. Results suggested that, the tailings particles gradually became finer along the dry beach surface to inside the impoundment. The particle size suddenly changed at the junction between the deposited beach and the water surface, which displayed an obvious coarsening phenomenon. Besides, the deposited beach exhibited the vertical feature of coarse upward and fine downward on the whole. Additionally, in the physical model, the saturation line elevated with the increase in dam height, and its amplitude was relatively obvious within the range of 1.0-4.5 m away from the initial dam. Under flood condition, the saturation line height was higher than that under normal condition on the whole, with the maximum height difference of 4 cm. This study could provide an important theoretical basis for further studies on dam failure experiments and the evolution rules of leaked tailings flow.

• Journal of Biosystems Engineering
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• 제30권2호
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• pp.69-74
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• 2005

This study was carried out to investigate experimentally the effect of the ground condition and tire inflation pressure on rolling characteristics of towed wheel, including the deformation, sinkage, effective rolling radius and motion resistance of tire. The experiment was performed at soil bin for the three levels of off-road conditions(ground-I, ground-II and ground-III) and a on-road condition(ground-IV), and for the four levels of tire inflation pressure which were 80 kPa, 160 kPa, 240 kPa and 320 kPa. The results of this study are summarized as follows: 1. As the tire inflation pressure of towed wheel increased, the tire deformation decreased exponentially, but the tire sinkage increased exponentially. This trend was getting bigger as ground condition was getting softer. 2. The increase of tire inflation pressure increased the effective rolling radius of towed wheel, and this kind of trend occurred greatly as ground condition was soft. As a result, the effective rolling radius for the off-road condition was always larger than that for on-road condition. 3. For the on-road condition, as the tire inflation pressure of towed wheel increased, the motion resistance decreased, but for the off-road condition, augmentation of tire inflation pressure increased the motion resistance. Also, the effect of inflation pressure on motion resistance appeared great as ground condition was soft. Therefore, in order to improve the tire performance by the control of inflation pressure, it is desirable to reduce the tire inflation pressure for off-road condition and to increase the tire inflation pressure for on-road condition.

• Journal of Biosystems Engineering
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• 제30권2호
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• pp.81-88
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• 2005

Manual transplanting Chinese cabbage needs 184 hours per ha in Korea. Mechanization of Chinese cabbage transplanting operation has been highly required because it needs highly intensive labor during peak season. This study was conducted to developed walking-type Chinese cabbage transplanter. In order to find out design factor of the transplanter, a kinematic analysis software, RecurDyn, was used. The prototype was tested in the circular soil bin and its operating motion was captured and analyzed using high speed camera system. Prototype was one row type which utilized original parts of engine, transmission and etc. from walking-type rice transplanter in order to save the manufacturing cost. Success ratio of pick-up device of hole-pin type and latch type were $96.0\%$ and $99.2\%$, respectively. which was highly affected by feeding accuracy of feeding device of seedling. Transplanting device of the prototype produced a elliptic loci which were coincident with those produced by the computer simulation. Prototype proved good performance in transplanting with mulching and without mulching operation, either. Working performance of prototype was 22 hours per ha and operation cost of the prototype was 961,757 won per ha. So, it would reduce $88\%$ of the labor and $29\%$ of operation cost.

• 농약과학회지
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• 제7권2호
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• pp.123-130
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• 2003

국내 과채류에 등록된 농약의 독성 및 토양잔류시험성적 등을 이용하여 포장에서 사용되는 농약에 대하여 환경영향 평가가 가능한 환경영향지수 모델을 만들고자 수행하였다 환경영향과 관련된 주요 평가 항목은 농작업자, 소비자, 생태계 및 환경영향항목으로 구성하였으며, 환경영향 평가는 rating 방식을 채택하여 환경영향지수 공식을 만들어서 사용하였다. 작물별 환경영향 지수는 참외에 등록된 농약이 농작업자, 소비자 및 환경에 대한 영향 지수가 다른 작물에 비하여 약간 높았고, 생태계에서는 고추에 등록된 농약이 가장 높았다. 또한 농약종류별 환경영향 지수를 비교한 결과는 살충제>상균제>제초제>생장조정제 순으로 높았으며, 전반적으로 과채류에 등록된 농약의 환경영향지수는 점차적으로 감소하는 추세였다.

• 한국산림과학회지
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• 제11권1호
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• pp.25-32
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• 1970

강원도산(江原道産) 적송림(赤松林)중 우량임분(優良林分)을 대상으로 해서 지위지수곡선(地位指數曲線)을 작성(作成)해 보았고 이에 대한 비평을 가했다. 시료관계(試料關係)로 기준연령(基準年令)을 25년(年)으로 잡았다. 작성방법(作成方法)으로서는 삼군분할법(三群分割法)을 적용했다. 다음에는 입목밀도(立木密度)를 검토(檢討)했는데 11개(個) plot의 입목도(立木度)는 기왕(旣往)의 수확표(收穫表)의 그것에 비해서 훌륭한 상태(狀態)에 있었다. 미국의 라이넥캐의 표준밀도에 비교한 이곳 적송임분(赤松林分)의 흉고직경(胸高直徑)대 단위면적(單位面積)당의 입목임수관계(立木林藪關係)를 제공했다. 이것을 보면 강원도적송림(江原道赤松林)의 밀도(密度)는 대단히 우량(優良)한 것으로 결론(結論)된다. 점밀도(點密度)로서 재적추정(材積推定)을 한다는 것은 신뢰성(信賴性)이 낮은 것이라는 토의(討議)를 가했고 조림학적(造林學的)인 또는 생태학적(生態學的)인 주요성으로 점밀도(點密度)의 개념을 선명했고 3가지 가설집단에 대해서 그 내용(內容)의 일단(一端)을 분석(分析)했다.

• 한국지반신소재학회논문집
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• 제16권2호
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• pp.67-77
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• 2017

본 연구에서는 콘 장비를 강관말뚝 중공에 설치함에 따른 말뚝의 거동을 분석하기 위해 축소 모형실험을 진행하였다. 콘 장비를 항타하여 설치 할 경우 먼저 강관 내부에 유입되는 관내토의 높이를 수치상으로 확인 할 수 있으며, 이를 통해 플러깅을 예측하여 플러깅에 따른 말뚝의 거동을 분석 할 수 있다. 또한 물리적인 항타 에너지로 지반의 강성과 강도를 증가 시켜 지지력을 상승 시킬 것으로 기대된다. 강사 장치를 이용하여 상대밀도 90%의 지반을 조성하고 거칠기가 다른 두 강관말뚝을 항타높이를 200mm와 500mm로 나누어 근입깊이 600mm까지 설치한다. 그리고 콘 장비의 유무에 따라 총 8가지 케이스를 나누어 말뚝의 지지력을 분석하였다. 말뚝의 항타높이, 말뚝의 거칠기, 콘 장비의 유무에 따른 세 가지 변수 중 항타높이가 약 70%로 지지력에 미치는 영향이 가장 컸으며 다음으로 콘 장비의 유무가 약 40%, 말뚝의 거칠기가 약 21%로 나타났다.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.37-47
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• 1984

Using the soil bin systems, this study was carried out to analyze the effects of the angular and tilling speed of the rotary shaft with the edge curves which were $30^{\circ}$ and $40^{\circ}$, and the edged blade which were single and double, on the torque requirement of rotary tillage. In the analyses, we developed the mathematical models for the torque requirments of rotary tillage, and analyzed the optimum conditions of each variable for the minimum tillage torque requriements. The results of the study were summarized as follows. 1. The required tilling torque by one rotary blade has the minimum value when the tilling speed of the rotary blade was low, and the revolution of the rotary blade was fast, in general. 2. The torque requirements of single edged blade was decreased to about 81% in comparing with that of double edged blade of which the edge curved angle was $40^{\circ}$ and the tilling speed was 29.40 cm/sec. But, for the mean values, the maximum torque requirements were decreased to 45%, and the mean torque requirements were decreased to 35%. 3. For the edge curved angle, the torque requirements of ${\theta}=40^{\circ}$ were 48% more than that of ${\theta}=30^{\circ}$ in the maximum tilling torque in case that the rotary blade were double edged blade. but, there was not a difference when the rotary blades were single edged blade. The mean tilling torques of ${\theta}=40^{\circ}$ were 6% more when the rotary blade was double edged blade, and were 11% less at single edged blade, than that of ${\theta}=30^{\circ}$. 4. In order to reduce the torque requirements for tilling, the optimum revolutions of the rotary shaft were analyzed as that 204-240 rpm for the double edged blade and 280-320 rpm for the single edged blade.