• 한국작물학회지
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• 제58권1호
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• pp.67-70
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• 2013

This research study was to develop methods for inhibiting the germination of cotton seeds. Germination rates after heating treatment at $80^{\circ}C$ with 10, 20, 30, 40 min. were 9.3, 9.3, 5.3 and 1.3 percentage, respectively. Heat treatment over $85^{\circ}C$ with 10 min. caused no germination of cotton seeds. Germination was significantly reduced with gamma rays treatment more than 10,000 gy, while the treatment within 2,000-8,000 gy induced less effects. Microwave processing for 30 seconds and 60 seconds inhibit the germination of cotton seed under 8 and 0%, respectively. As a physical treatment, rollmill milling with 1.5, 2, 2.5 mm gap inhibited any germination of cotton seeds. The optimum gap of roll-mill for processing physical cracking was below 51% of the thickness of seed.

• 대한산업공학회지
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• 제18권1호
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• pp.25-36
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• 1992

A possible adverse effect on the likelihood of front-seat occupant fatalities from unbelted rear-seat occupants in frontal crashes is investigated using Fatal Accident Reporting System data. Passenger cars which sustained frontal damage and which did not roll over are included in this analysis. Of the frontally damaged cars, only cars containing a driver and a right-front passenger are selected. Then, from these cars, the following three cases are considered: a) left-rear occupant present, b) right-rear occupant present, and c) no one else in the car. Cars belonging to a) or b) contain only three occupants, and those belonging to the last case contain only two occupants. In addition, all occupants are unbelted. To estimate the influence of rear-seat occupants on front-seat occupant fatalities, relative risks of driver and right-front passenger fatalities are compared pairwise across these three cases. The adverse influence of unbelted rear-seat occupants on the likelihood of unbelted front-seat occupant fatalities in frontal crashes is estimated to be 7.9% ${\pm}$ 45%(the error limits indicate one standard error). In other words, front-seat occupant fatalities are increased 7.9% in frontal crashes due to the loadings from unbelted rear-seat occupants. This suggests that the usage of safety belts by rear-seat occupants not only may extend their own lives but also helps in reducing the fatalities of front-seat occupants seated in front of them.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제45차 학술발표회
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• pp.63-63
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• 2011

통상적으로 코팅가공시 수지의 흐름성을 개선하기 위해서 코팅수지(점도 : 50,000~60,000 Cps)의 점도를 10,000 Cps 이하로 낮추어서 작업을 진행한다. 이때 MEK(Methyl Ethyl Ketone), TOL(Toluene), DMF(Dimethyl Formamide) 등과 같은 유기용제를 사용하여 점도를 조절한다. 본 연구는 기존에 표면처리 코팅용 수지 배합시 유기용제를 사용하는 대신 물을 사용하여 점도 조절이 가능한 표면처리 코팅용 hydrophilic PU 수지를 연구하였다. Prepolymer 법으로 합성한 수지가 One-shot법으로 합성한 수지보다 water dilution 안정성이 우수하며, 친수성 polyol과 소수성 polyol의 비율이 6/4정도가 될 때 water dilution된 수지의 안전성, 투습도 등의 물성이 가장 이상적으로 발현 되는 것을 확인 할수 있었고, 50part의 물과 희석 후 5일 이후에도 상분리가 되지 않음을 확인 할 수 있었다. 개발된 수지의 적용성을 평가한 결과, J-knife를 이용하여 knife over roll 방식으로 $200{\mu}m$의 gap으로 80/120/$140^{\circ}C{\times}10m/min.$의 다단건조 공정으로 진행했을 때 최적의 물성을 얻을 수 있었다.

• 한국재료학회지
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• 제32권10호
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• pp.414-418
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• 2022

Magnesium alloy is the lightest practical metal. It has excellent specific strength and recyclability as well as abundant reserves, and is expected to be a next-generation structural metal material following aluminum alloy. This paper investigated the possibility of thin plate fabrication by applying a overheating treatment to the melt drag method, and investigating the surface shape of the thin plate, grain size, grain size distribution, and Vickers hardness. When the overheating treatment was applied to magnesium alloy, the grains were refined, so it is expected that further refinement of grains can be realized if the overheating treatment is applied to the melt drag method. By applying overheating treatment, it was possible to fabricate a thin plate of magnesium alloy using the melt drag method, and a microstructure with a minimum grain size of around 12 ㎛ was obtained. As the overheating treatment temperature increased, void defects increased on the roll surface of the thin plate, and holding time had no effect on the surface shape of the thin plate. The fabricated thin plate showed uniform grain size distribution. When the holding times were 0 and 30 min, the grain size was refined, and the effect of the holding time became smaller as the overheating treatment temperature increased. As the overheating temperature becomes higher, the grain size becomes finer, and the finer the grain size is, the higher the Vickers hardness.

• 한국해양공학회지
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• 제36권5호
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• pp.295-302
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• 2022

The initial response to a marine accident can play a key role to minimize the accident. Therefore, various decision support systems have been developed using sensors, simulations, and active response equipment. In this study, we developed an algorithm to predict damage locations using ship motion data with bidirectional long short-term memory (BiLSTM), a type of recurrent neural network. To reflect the low frequency ship motion characteristics, 200 time-series data collected for 100 s were considered as input values. Heave, roll, and pitch were used as features for the prediction model. The F1-score of the BiLSTM model was 0.92; this was an improvement over the F1-score of 0.90 of a prior model. Furthermore, 53 of 75 locations of damage had an F1-score above 0.90. The model predicted the damage location with high accuracy, allowing for a quick initial response even if the ship did not have flood sensors. The model can be used as input data with high accuracy for a real-time progressive flooding simulator on board.

• 무역학회지
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• 제47권5호
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• pp.59-74
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• 2022

The exemption clause of recurring shipments refers to the insurer's exemption in Short-term Export Credit Insurance for the additional shipment which was shipped on board while any foregoing shipment was unpaid beyond its due date over 30 days. The recurring shipments are constituted with two factors: the due date of the foregoing shipment and the shipment date of the additional export. The exemption clause of recurring shipments has been eased by extending the grace period for payment up to 60 days from 30 days for the transactions between exporters and importers having the history of payments which were made customarily in delay. This research argues that the current grace period is for the buyers who customarily delay their payments, and that the insurer introduce a grace period for shipment in favor of exporters for the additional shipment which was delayed in on-boarding due to reasons beyond the control of exporters. In consideration of the waiting time and the on-boarding time at ports for container freight, shipments are frequently delayed, which entails those shipments to be indemnified by the exemption clause of recurring shipments. Roll-overs and Blank Sailings also cause the container freight to be delayed in on-boarding. This research is expected to contribute to further development of Short-term Export Credit Insurance in K-SURE.

• Journal of Biosystems Engineering
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• 제39권1호
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• pp.21-33
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• 2014

Background: Significant technological development and changes happened in the tractor industries. Contrariwise, the test procedures of the major standard development organizations (SDO's) remained unchanged or with a little modification over the years, demanding new tractor test standards or improvement of existing ones for tractor performance, safety, and comfort. Purpose: This study focuses on reviewing the research trends regarding performance, safety and comfort evaluation of agricultural tractors. Based on this review, few recommendations were proposed to revise or improve the current test standards. Review: Tractor power take-off power test using the DC electric dynamometer reduced human error in the testing process and increased the accuracy of the test results. GPS signals were used to determine acceleration and converted into torque. High capacity double extended octagonal ring dynamometer has been designed to measure drawbar forces. Numerical optimization methodology has been used to design three-point hitch. Numerous technologies, driving strategies, and transmission characteristics are being considered for reducing emissions of gaseous and particulate pollutants. Engine emission control technology standards need to be revised to meet the exhaust regulations for agricultural tractors. Finite Element Analysis (FEA) program has been used to design Roll-Over Protective Structures (ROPS). Program and methodology has been presented for testing tractor brake systems. Whole-body vibration emission levels have been found to be very dependent upon the nature of field operation performed, and the test track techniques required development/adaptation to improve their suitability during standardized assessment. Emphasizes should be given to improve visibility and thermal environment inside the cab for tractor operator. Tractors need to be evaluated under electromagnetic compatibility test conditions due to large growing of electronic devices. Research trends reviewed in this paper can be considered for possible revision or improvement of tractor performance, safety, and comfort test standards.

• 한국철도학회논문집
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• 제10권5호
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• pp.540-545
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• 2007

틸팅 열차는 곡선 구간에서 차체가 안쪽으로 기울어져 고속으로 회전해도 탈선하지 않는 열차를 말한다. 여러해 동안 한국철도기술연구원에서는 이 열차를 개발해왔다. 이 논문에서는 그동안 개발되어온 틸팅 열차의 동역학해석을 수행하였다. 이를 통해서 국제기준에 맞는 안정성과 주행성능을 지니고 있는지 확인하고 향후 속도 개선의 기본 자료를 생성하였다.

• 지능정보연구
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• 제17권4호
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• pp.143-155
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• 2011

본 논문에서는 RFID 기반의 전자 팔찌를 이용한 전자 출석부 및 어린이 보호팔찌 시스템을 제안한다. 제안된 시스템에서는 임베디드시스템 기반의 RFID 기술을 응용한 전자 출석부가 필요하며, 위치 추적과 동시에 범인의 전자 팔찌와 반응할 수 있는 GPS 시스템이 있어야 한다. 또한 이동 통신 모듈을 이용한 RFID 전자 팔찌와 임베디드시스템 기반의 RFID 출입 통제 시스템이 필요하며 상황정보를 전송 받을 수 있는 스마트폰 등의 모바일 시스템이 있어야 한다. 이렇게 동시에 연동될 수 있는 장비와 시스템들을 융합하여 사용한다면 아이들이 안전하게 유치원이나 학교를 다닐 수 있을 것이다. 본 논문의 구성은 RFID 리더기와 임베디드시스템 기반의 전자 출석부(고정용 리더기) 및 출입 통제 시스템, RFID 태그와 리더기, GPS 및 이동 통신 모듈(CELL 방식)를 활용한 추적 시스템을 가진 전자 팔찌로 이루어져 있다.

• Ecology and Resilient Infrastructure
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• 제3권4호
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• pp.231-237
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• 2016

본 연구에서는 여재와 식생을 결합한 수질정화기술에 적용된 여재의 흡착특성을 파악하고, 장기 여과실험에 따른 제거효율의 추이를 관찰하였다. 연구대상 여재는 Adphos이며 인산염 인 ($PO_4{^{3-}-P}$) 흡착특성 분석결과 Adphos는 Langmuir 흡착모델에 적합한 것으로 분석되었고 이 모델에 적용 시 인산염 최대흡착량 ($q_m$)은 1.162 mg/g 으로 산출되었다. 정화기술의 효율을 검증하기 위하여 Adphos의 두께를 400 mm로 충진한 실험실 규모 반응기를 제작하였다. 식생부는 노랑꽃창포 (Iris pseudacours L.)를 식재하였고 식물의 활착을 위한 기반재는 야자섬유 롤 (coir roll)을 사용하였다. 일일 8시간씩 71일간 여과실험을 지속한 결과 융복합형 반응기의 평균 제거효율은 SS, T-N, T-P 각각 94%, 41%, 64%로 나타났다. 실험 결과에 따라 정화기술의 성능이 우수한 것으로 사료되며, 부도기술의 장기 적용을 위한 유지관리방안 마련이 요구된다.