• 한국농공학회지
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• 제15권3호
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• pp.3089-3095
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• 1973

The power transmission to the traction devices may be very important for the tractor performance and therefore this system has been studied very much in the past. On the other hand, the PTO(Power-take-off) has been considered as an accessary on the tractor with a few work for its power transmission. Because of increased use of PTO operation in various kind of farming operations in recent years, the function of PTO may become such important as the traction facilities. In this study, the power transmission characteristics of PTO drive was analyzed theoretically and some experimental work was done to study on it. The results of the study are as follows: 1) The most stable condition of PTO work was obtained when the intersection angle of the two curves for driving and driven torques was about ${\pi}/2$. 2) To obtain the most stable operation it is better to use both the speed control and the full control together. 3) Six steps differential gear may not be enough to use the PTO power smoothly. It is thought that the three steps differential gear on the shaft of PTO may be necessary additionally for a smooth operation. 4) When the traction facilities and the PTO are used at the same time, the torque of crank shaft becomes Tt + Tp, and the high efficiency and good stability of word will be obtained with the small variation of driving speed. 5) When the tractor was operated with 75% of the rated horse power and 70% of maximum speed, the best thermal efficiency could be obtained. 6) The most dangerous sound for human occured at the rated speed of PTO and tus it may be necessary to control the dangerous noise.

• 한국융합학회논문지
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• 제9권10호
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• pp.61-67
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• 2018

본 연구는 실시간 가스 안전 모니터링 앱의 개발 작업을 3년 동안 실시한 후 도출된 결과물들을 담고 있다. 가스 작업장의 사고 위험을 축소하기 위해서는 위험물질, 위험 설비 등의 위치와 안전 절차, 작업장의 온습도 등을 작업자들이 인지할 수 있도록 정보를 제공하는 것이 필수적이다. 따라서 본 연구는 메인 시스템이 이러한 정보들을 지속적으로 업데이트 하는 현장에서 작업자들이 이를 효율적으로 수신할 수 있는 모니터링 앱의 개발을 목적으로 진행되었다. 그동안의 연구에서 이루어진 사항들과 메인 시스템의 웹 화면을 기본으로 하여 도출된 앱 시나리오에 대한 정량적, 정성적 조사 및 분석결과, 사용용이성, 가독성, 직관성 면에서의 수정과 개선이 이루어졌다. 특히 사용용이성의 하위 영역인 낮은 depth에서 많은 개선을 하였다. 최종적으로 도출된 앱 시나리오에 대해 사용자 요구 부합도 조사를 한 결과 기능성, 편리성 가독성 면에서 평균 98.5점의 평가를 받았다.

• 한국전자거래학회지
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• 제22권2호
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• pp.1-18
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• 2017

오늘날 감정 표현이 서툰 영유아가 처한 극도의 스트레스 상태를 자동적으로 파악하는 것은 영유아의 안전을 위협하며 지속적으로 발생하는 위험 상황의 실시간적인 인지를 위해 반드시 필요한 기술이다. 따라서 본 논문에서는 생체신호를 활용하여 영유아의 스트레스 상태를 분류하기 위한 기계학습 기반의 모델과 생체신호 수집용 스마트 밴드 및 모니터링용 모바일 어플리케이션을 제안한다. 구체적으로 본 연구에서는 영유아의 감정을 나타내는 주요한 요인이 되는 음성 및 심박 데이터의 조합을 활용하여 기존에 널리 알려진 데이터 마이닝 기법을 통해 영유아의 스트레스 상태 패턴을 학습하고 예측한다. 본 연구를 통해 생체신호를 활용하여 영유아의 스트레스 상태 식별을 자동화할 수 있는 가능성을 확인하였으며 나아가서 궁극적으로 영유아의 위험 상황 예방에 활용될 수 있을 것으로 기대된다.

• 한국가스학회지
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• 제19권4호
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• pp.15-21
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• 2015

최근 발생한 크고 작은 화재 폭발 누출 사고들을 살펴보면, 하청업체의 근로자들이 원청업체 사업장에서 유해 위험한 정비 보수작업 중에 재해를 당하는 사고가 증가하고 있다. 따라서 본 연구에서는 공정안전보고서 제출대상 사업장을 대상으로, 설문조사를 통해 도급업체의 안전관리 실태를 파악하고, 도급업체의 안전관리 향상을 위해 공정안전관리를 활용한 원청업체와 하청업체간의 책임과 합리적 역할분담, 안전 보건정보 제공, 정비 보수작업 시 근로자 보호 방안을 제안하였다. 본 연구결과는 유해 위험작업 시 하청업체의 안전관리 강화와 개선에 도움을 주고, 원청업체와 하청업체간의 상생 협력관계를 구축하여 산업재해를 감소시키는데 활용될 수 있을 것으로 기대된다.

• Journal of Mechanical Science and Technology
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• 제16권11호
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• pp.1485-1496
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• 2002

In order to investigate the fire-induced smoke movement in a three-dimensional room with an open door, numerical and experimental study was performed. The center, wall, and corner fire plumes for various sized fires were studied experimentally in a rectangular pool fire using methanol as a fuel. The numerical results from a self-developed SMEP (Smoke Movement Estimating Program) field model were compared with experimental results obtained in this and from literature. Comparisons of SMEP and experimental results have shown reasonable agreement. As the fire strength became larger for the center fires, the air mass flow rate in the door, average hot layer temperature, flame angle and mean flame height were observed to increase but the doorway-neutral-planeheight and the steady-state time were observed to decrease. Also as the wall effect became larger in room fires, the hot layer temperature, mean flame height, doorway-neutral-planeheight and steady-state time were observed to increase. In the egress point of view considering the smoke filling time and the early spread of plume in the room space, the results of the center fire appeared to be more dangerous as compared with the wall and the corner fire. Thus it is necessary to consider the wall effect as an important factor in designing efficient fire protection systems.

• 한국항해항만학회지
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• 제36권4호
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• pp.279-284
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• 2012

This study aims to identify the degree of safety when mariners take their actions in several different situations. We have carried out many experiments to observe mariners' behavior and then measured the safety level based on their actions to avoid dangerous situations of ships collision. One of the most important actions that mariners have to take, either as their daily routine or when they are in a collision situation and then want to avoid that situation is the lookout. In this paper, behaviors on the lookout have been defined as a standard sequence of three steps which are "time of first detection", "time of recognition as risky vessel" and "time of starting avoiding action", and the suitability and applicability of the definition have been shown. And also we propose the risk assessment on ships collision and the recommendation for reducing ships collision at sea. Some analyzing results and the application of the results are reported. By combining these knowledge and some systematic studies, we propose the risk assessment on ships collision and the recommendation for reducing ships collision at sea.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.505-510
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• 2011

The railroad freight transport has great merits that can transport mass and specific items(dangerous goods), but it takes a long time because of low accessibility to the logistics facility and the complex process of loading freight in middle station. This paper analyzed volumes and characters of each railroad freight item, and was carried out the effect of applying E&S system to Gyeongbu line containers to find the method of reducing transport time and effective container transportation. As a result of Cost-Effectiveness analysis, the block train(B/T) is reducing transport time more about 1~2 hours. The road congestion cost is saving about 2.2 billion won. And due to skipping work of organizing train, personnel and equipment expenses savings expected about 9 billion won. It is expected that the E&S system enhances the container transport service and has an effect positive influence on making a efficient method of transport. But It is necessary to estimate pre-feasibility of applying E&S system that the standard of estimating cost and benefit is required further examination.

• 대한인간공학회지
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• 제13권1호
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• pp.27-35
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• 1994

Automation and mechanization of work make people put the machine into operation and control the state of operation. In the process of those works they are apt to have accidents caused by their carelessness. To reduce such accidents, we can practice "TOUCH '||'&'||' CALL", which is to indicate and ascertain the dangerous parts at every process before performing tasks. The objectives of this study are to examine the effects of S-R compatibility and to show quantitatively the efficiency of TOUCH '||'&'||' CALL. The results show that: 1. Reaction time in case of indicating with fingers and shouting is slightly longer (0.138sec. .approx. 0.279sec. ) than that of responding only visually. However, the error rate decreases by 1/3.3 .approx. 1/4.2 times. Frome this, it is considered to verify quantitative estimation on multiple feedback of TOUCH '||'&'||' CALL. 2. In the stimulus-response relation aspect, numeric numeric stimulus-numeric response shows lower error rate (0.033% .approx. 0.133%) than any other stimulus-response relation, ahd shorter reaction time is proven ( 0.556sec. .approx. 0.835sec. ). These data suggest that having the order of stimulus-response arranged in accordance with the experimental knowledges and conceptional compatibility can bring down the error rate considerably.

• 한국자동차공학회논문집
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• 제20권3호
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• pp.113-118
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• 2012

Collision detection plays a key role in collision mitigation system. The malfunction of the collision mitigation system can result in another dangerous situation or unexpected feeling to driver and passenger. To prevent this situation, the collision time, offset, and collision decision should be determined from the appropriate collision detection algorithm. This study focuses on a method to determine the time to collision (TTC) and frontal offset (FO) between the ego vehicle and the target object. The path prediction method using the ego vehicle information is proposed to improve the accuracy of TTC and FO. The path prediction method utilizes the ego vehicle motion data for better prediction performance. The proposed algorithm is developed based on laser scanner. The performance of the proposed detection algorithm is validated in simulations and experiments.

• 한국식품위생안전성학회지
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• 제11권3호
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• pp.177-187
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• 1996

Time-temperature relationship and microbiological quality were assessed and critical control points were identified through hazard analysis during the phases of production in two different packaged meals (Dosirak) manufacturing establishments (A, B:Kim Pab). Microbiological tests on foods, equipments and utensils were done according to standard procedures and included total plate count, coliforms and fecal coliforms. The results of the study are summarized as follows : time-temperature control management was needed because time-temperature abuse more than 8 hours at dangerous temperature zone (5-6$0^{\circ}C$) was observed from pre-preperation to distribution phase; Poor sanitary practices of employees were observed in hand washing and using disposable gloves; Microbiological analysis results of equirpments and utensils showed possible cross-contamination risks when foods were contacted with them; Kim Pab needed thorough quality control because it included various mixed ingredients of cooked and uncooked and had many apportunities of cross-contamination either by equipments or hands through whole production processes.