• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2003년도 하계 학술대회 논문집
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• pp.309-316
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• 2003

참깨탈곡의 생력기계화를 위해 일관작업이 가능한 참깨탈곡기를 개발하여 시험한 결과를 요약하면 다음과 같다. 가. 타격식 탈곡요인시험 결과 타격수 14, 17cpm에서 탈곡률은 98.5, 98.7%, 미탈곡률은 1.1, 1.0%, 배출구 손실률은 0.4. 0.3%로 가장 양호하게 나타났다. 나. 타격식 탈곡물의 정선요인시험결과 경사 12$^{\circ}$, 요동수 220cpm일 때 탈곡률과 미정선 손실률이 각각 97.2%와 0.6%로 가장 양호하게 나타났다. 다. 타격식 탈곡부와 정선부를 조합한 시작기의 성능시험결과 공급량 15단/min, 타격수 14cpm, 정선체 요동수 220cpm에서 탈곡률은 98.7%, 탈곡부 손실률은 1.3%, 정선율은 97.0%, 미정선 손실률 0.7%로 나타났다. 라. 시작기는 10a당 작업성능이 0.5시간으로 인력 4.8시간에 비해 9.6배 능률적이고 소요경비가 17,471원으로 인력 32,290원에 비해 45.9% 절감되는 것으로 나타났다

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.489-497
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• 2000

Since Chinese cabbages weigh 3 to 5kgf and are big in size at the time of harvest, handling operations such as harvesting, loading and unloading including transportation require the highest labor demand among all other cultivation processes. Recently, though several cabbage harvesters were developed in Japan and Europe, those harvesters were not suitable for Chinese cabbages cultivated in Korea because of the size and shape. The cabbage harvester is almost meaningless without any proper cabbage piling and pallet unloading mechanism. Most harvesters developed so far adopted a sort of slide and free falling way in collecting cabbages into the pallet. Three or four labors are usually required for cleaning incoming cabbages and loading those in the pallet. Because of the required time for piling cabbages without severe damage and the required space capacity to carry empty and loaded pallets, harvesting speed should be adjusted in accordance with time required for consecutive operations. Up to now, any automatic or semi-automatic collecting device has not been developed in the world to pile cabbages on the layer one by one into the pallet in the ordered way with little damage and to unload pallet from the harvester continuously during the harvest process. To compromise system expenses and function, Semi-automatic cabbage piling and pallet unloading mechanism was devised and it required one labor. The foldable mesh pallet with a size of 1050mm x 1050mm x 1000mm and holding capacity of around 70 cabbages was utilized. The prototype for piling and unloading mechanism was composed of three parts such as feeding device, automatic piling device with retractable bellows, and pallet unloading device. Prior to developing the prototype, the geometric properties and the amount of the damage of the cabbage caused during the piling operation were investigated. Considering the height of the pallet, a series of cabbage carrying plates were mounted to the bracket chain to lift and to carry cabbages to the loading device. Indoor laboratory experiments showed that the cabbage carrying chain conveyor worked successfully. Considering the conveying speed 0.46m/sec of the pull up belt from the cabbages on the ground, the speed of cabbage carrying chain conveyor worked property in the range of 0.26m/sec to 0.36m/sec. The system allowed the operator to modify the position of cabbage slightly. Overall system worked successfully resulting into almost same capacity without severe damage to the cabbage as human did.

• 한국산업보건학회지
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• 제31권2호
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• pp.138-146
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• 2021

Objectives: This study aims to compare and evaluate the reduction efficiency of disinfectants used in the domestic meat processing industry to reduce bioaerosol exposure of meat industry workers and to use this as basic data for establishing work environment management measures. Methods: Thirteen disinfectants sold in South Korea were selected for evaluation and the bacterial reduction effect of the disinfectants was investigated. Bacterial suspension and surface disinfection tests were conducted to compare and analyze the antibacterial strength of the disinfectants. Pork carcasses, cutting boards, benches, and conveyor belts were selected for surface sterilization tests. Results: As a result of the bacterial suspension experiment test, all disinfectants had a bacterial reduction efficiency of more than 86%. Among them, the bacterial reduction efficiency of chlorine disinfectants was 99.93% on average. In the results of the pork carcass surface sterilization test, the rate of reduction of disinfectants made of quaternary ammonium compounds (QACs) was the highest. Tests of plastic cutting boards showed that chlorine disinfectants had the best sterilization effect. Experiments on stainless steel benches showed the best bacterial reduction efficiency for chlorine dioxide and QACs disinfectants. In the conveyor belt made of urethane, QACs disinfectants showed excellent sterilization effects. Conclusions: The study evaluated the disinfection power of disinfectants against bacteria occurring in domestic meat processing plants. All disinfectants were found to be effective in bacterial suspension experiments, and chlorine disinfectants were particularly effective. In surface sterilization experiments, sterilizing agents with QACs as the main ingredient were excellent.

• 한국축산시설환경학회지
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• 제14권1호
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• pp.47-52
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• 2008

1. 조사농장의 산란율은 하이라인, 이사브라운 모두 $85{\sim}93%$ 수준 이였으며, 농가자체 파란율은 하이라인 $1.5{\sim}2.2%$, 이사브라운 $1{\sim}1.4%$이었다. 2. 계란 이송단계별 파란발생비율은 집란벨트 4.7%> 엘리베이터 2.5%> 선란기 1.7%> 컨베이어 0.9% 순 이었다. 3. 집란벨트에서 엘리베이터로 이송 중 계란이송가이드를 설치할 경우 약 1%의 파란경감 효과가 있는 것으로 나타났다. 4. 하이라인 브라운은 주령이 높아지면서 파란율은 높아지고, 파각력은 낮아지는 것으로 나타났으며, 회귀계수 분석 유의성은 $R^2=0.7$로 파각력의 변화가 파란율에 영향을 미치는 것으로 분석되었다. 5. 이사브라운에서는 환우 전에 비하여 환우 후 파각력이 높아진 것으로 나타났다. 6. 난각 두께와 파각력, 그리고 접촉 후 파각변위와 파각력과의 관계에서 이들 함수의 변수간에 회귀관계는 유의성이 나타나지 않았다.

• Journal of Biosystems Engineering
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• 제31권6호
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• pp.514-523
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• 2006

Production of green pepper has been increased due to customer's preference and a projected ten-year boom in the industry in Korea. This study was carried out to develop an automatic grading and sorting system for green pepper using machine vision. The system consisted of a feeding mechanism, segregation section, an image inspection chamber, image processing section, system control section, grading section, and discharging section. Green peppers were separated and transported using a bowl feeder with a vibrator and a belt conveyor, respectively. Images were taken using color CCD cameras and a color frame grabber. An on-line grading algorithm was developed using Visual C/C++. The green peppers could be graded into four classes by activating air nozzles located at the discharging section. Length and curvature of each green pepper were measured while removing a stem of it. The first derivative of thickness profile was used to remove a stem area of segmented image of the pepper. While pepper is moving at 0.45 m/s, the accuracy of grading sorting for large, medium and small pepper are 86.0%, 81.3% and 90.6% respectively. Sorting performance was 121 kg/hour, and about five times better than manual sorting. The developed system was also economically feasible to grade and sort green peppers showing the cost about 40% lower than that of manual operations.

• 연구논문집
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• 통권23호
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• pp.127-140
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• 1993

The drive pulley, which is employed for loading and unloading raw materials in a steel mill, is usually manufactured by use of various welding processes. In this study the weldment in the pulley, in which TIG and $CO_2$ welding processes are used, has been analyzed from view point of fracture mechanics. Fracture toughness tests have been performed according to ASTM E813. A servo-hydraulic testing machine (10kN) has been employed. Also the crack propagation tests (Mode I) have been performed with compact tension specimen in compliance with ASTM E647. To predict the critical crack size in the weldment, finite element stress analysis for the drive pulley under real operating conditions have been performed. In addition, the residual stresses at the weldment and in heat-affected zone have been obtained by hole drilling method. The planar critical crack size have been predicted for the drive pulley by considering the stress analysis results and the residual stresses due to welding process. For the drive pulley considered in this study, it has been concluded that the most important factor in determining the critical crack size is the welding residual stress in the transverse direction. Also the effect of stress concentration at the root of the weldment have been noticeable. For the planar crack, the fatigue crack growth life from an initial crack size of 2mm to the critical crack size obtained as in the above have been predicted. The predicted lives were between 55, 900 and 72, 000 cycles depending on the shape of the elliptical crack. The predicted lives were in fairly good agreement for the drive pulley considered in this study.

• 한국정보통신학회논문지
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• 제21권11호
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• pp.2037-2042
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• 2017

스마트 공장은 미리 입력된 프로그램에 의해 생산시설이 수동적으로 움직이는 공장 자동화 작업 방식과는 달리, 생산 설비 스스로 작업 방식을 결정하여야 한다. 생산 설비 스스로 작업 방식을 결정이라 함은, 이를테면 제조 현장에서 설비의 노후, 문제 발생 예측, 제품의 불량 검출 등과 같은 이상 징후가 발생할 시 이를 조기에 발견한 후 스스로 문제를 해결하는 것을 의미한다. 본 논문에서는 제조 현장의 제조 공정 이상 징후 감지를 위해 대기행렬을 이용한 제조 공정 모델링을 제시하고 해당 모델링에서 이상 징후를 기계학습 기술 중 하나인 SVM을 이용하여 이를 감지하도록 한다. 해당 대기행렬을 M/D/1을 사용하였으며, ${\mu}$, ${\lambda}$, ${\rho}$를 기반으로 컨베이어 벨트 제조 시스템을 모델링하였다. SVM을 이용하여 ${\rho}$의 변화량을 통해 이상 징후를 감지했다.

• 대한조선학회논문집
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• 제48권5호
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• pp.381-389
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• 2011

In this study, we are focusing our attention on lift characteristics of the low aspect wings for Wing-In Ground effect crafts (WIG). Experimental measurements at an open-type wind tunnel are carried out and results are comparatively presented. In order to simulate the realistic ground condition in where the WIG craft is flying, moving ground is implemented by a conveyor belt rotating with the same velocity of the inflow. We consider two different wings (NACA0012 and DHMTU section) which have four different aspect ratios (0.5, 1.0, 1.5 and 2.0). Forces acting on the wings are measured and lift characteristics are elaborately investigated for various different conditions. In addition, end-plate effects are estimated. Results are validated by comparing with theoretic solutions of the symmetric airfoil. Present results show that ground effects are differently generated in moving or fixed ground conditions, and hence left characteristics are affected by the ground condition. Consequently, accurate aerodynamic forces acting on the WIG craft are guaranteed in a realistic moving ground condition.

• 한국지반신소재학회논문집
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• 제14권1호
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• pp.33-41
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• 2015

본 연구에서는 관중혼합처리공법 개발을 위해 혼합토의 공학적 특성 평가에 관한 실내실험(유동성, 단위중량, 일축압축강도 및 블리딩 시험)을 수행하였다. 실험 결과 흐름 및 블리딩 특성은 함수비에 비례하여 증가하는 것으로 나타났다. 단위중량과 일축압축강도는 함수비 증가에 따라 감소하는 것으로 나타났다. 각 주행 장비별 접지압과 혼합토의 지지력을 비교한 결과 벨트 컨베이어, 백호우, 도저 등의 장비가 즉시 진입 가능한 것으로 검토되었다. 결과적으로 고화재를 사용한 관중혼합처리공법에서 적용 가능한 함수비 영역은 80~200%로 평가되었다. 또한, 본 연구 결과로부터 설계 차트를 개발하여 제시하였다.

• 한국콘텐츠학회논문지
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• 제11권3호
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• pp.18-25
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• 2011

현재 주화의 제조 공정에서는 주화의 표면 품질 진단을 사람이 눈으로 직접 확인하여 수행하고 있다. 본 논문은 컨베이어 벨트에 놓이어 이동하는 주화로부터 획득한 영상을 이용하여 주화 표면의 결함을 검출하는 영상처리 방법을 제시한다. 결함 검출 방법은 영상에서 주화 영역을 분할하고, 분할된 동전을 비교할 모델에 정렬하며, 정렬된 영상을 최적의 고유 영상 공간으로 투영, 투영 오차와 학습된 가변 임계값과 비교하여 결함 부위를 검출한다. 본 논문에서는 이러한 일련의 영상처리 과정 중에서 주화 표면 진단과 관련하여 특화된 새로운 방법을 제시한다. 주화의 정렬을 위하여 분할된 주화의 히스토그램을 사용한다. 이 방법은 2차원 영상의 정렬을 일차원 히스토그램의 정렬로 변환하는 것이다. 다음으로 정렬된 영상을 고유 영상공간에 투영시켜 주화 방향에 따른 휘도 변화를 보정한다. 이 방법은 소수의 고유 영상 벡터들로 구성된 고유 영상 공간을 여러 개 생성하고, 최적의 고유 영상 공간에 정렬된 영상을 투영하여 실시간 구현이 가능하게 한다.