• Journal of Biosystems Engineering
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• 제18권4호
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• pp.358-370
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• 1993

In Korea, fruit grading has been mainly done manually, and manual grading depends on human sense. Thus it is subjected to human error and is not always as consistent as would be desired. Therefore, a study on the development of fruit grader was initiated to improve the consistency of fruit grading. The sensitivity for fruit weight of the conventional spring type weight grader has a tendency to decrease by physical characteristics of spring which is used as a weight sensing unit. This study was carried out to develop weight measuring device for establishing the base of weight sensing unit of electronic weight grader. This device consists of a weight sensor using load cell, data acquisition system, and a microcomputer containing program to calculate fruit weight. The weight measuring device using load cell was developed to increase sensitivity of fruit weight. The result of this study showed that the weight sensing unit of electronic weight grader contributed to the improvement of performance of weight measuring device.

• Journal of Biosystems Engineering
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• 제17권4호
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• pp.363-369
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• 1992

The aim of this study was to examine the blurring effects on performance of the experimental fruit grader in grading Fuji apples by size and coloration of the whole surface of individual apples. The grader consisted of a black/white image prcessing system, one camera, and utilized the algorithm developed for high speed sorting in the previous study. The results are summarized as follows : 1. With the algorithm developed in the previous study, it took 0.27~0.33 second in analyzing the size and coloration of an apple, and relative errors were within 3% for size and 1.3% for coloration. 2. The effect of blurring increased linearly with the conveying speed of apple and showed more significant effect on detection of coloration than on determining of size. 3. Considering the blurring effect, capacity of the experimental fruit grader was estimated to 7,500 apples per hour.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1292-1301
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• 1993

This study was intended to examine feasibility of sizing and color grading of Fuji apple with black/white image processing system , to develop a device with which the whole surface of an apple could be captured by one camera , to develop an algorithm for a high speed sorting , and to examine the effects of blurring on the performance of the experimental fruit grader.

• 현장농수산연구지
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• 제8권1호
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• pp.21-29
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• 2006

우리사과의 재배노력 절감으로 대외경쟁력 향상을 위한 기초 자료로 활용코자 몇가지 실험을 수행한 결과는 다음과 같다. 사과 수확시 및 선별시 과경에 의한 과피의 상처발생은 선별시 보다 수확시에 많이 발생하였고 대과에서 상처발생이 심하였다. 사과 수확시 과경을 절단하면서 수확하면 과경을 절단하지 않고 수확하는 것보다 수확량이 반이하로 줄어서 수확노력이 배 이상 소요된다. 사과 선별기의 접시와 집적판 사이의 간격이 0cm인 경우에 소과에서 과피에 상처가 적게 발생하였다. 사과의 과경을 절단하여 저장하는 것이 과경을 무절단하여 저장하는 것 보다 과중이 크게 감소되어 저장시에는 사과의 과경을 절단하지 않도록 하여야 할 것으로 생각되며 사과의 과경절단 유무에 따른 사과의 경도는 차이가 없었다. 경와부 밖으로 돌출된 사과과경의 길이는 사과의 크기와 차이가 없는 경향 이었다. 따라서 사과의 과경을 절단하지 않음으로서 과경절단에 소요되는 노력절감 및 과경절단 비용을 소득화 하고 원활한 대일 수출, 품질유지 등에 기여하였으면 한다.

• Journal of Biosystems Engineering
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• 제20권1호
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• pp.95-103
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• 1995

A series of study has been conducted to develop a multi-purpose fruit grader using a black ＆ white image processing system equipped with a 550 nm interference filter. A device and high performance algorithms were developed for sizing and color grading of Fuji apple in the previous study. In this study an emphasis was put on finding correlations between weights of several kinds of fruits and their area fractions(AF), and on compensating the blurring effect upon sizing and color grading by conveying speed of fruit. Also, the effect of orientation and direction of fruit on conveyor during image forming was analyzed to identify any difficulty (or utilizing an automatic fruit feeder. The results are summarized as follows. 1. The correlation coefficients(r) between the weights of fruits and their image sizes were 0.984~0.996 for apples, 0.983~0.990 for peachs, 0.995 for tomato, 0.986 for sweet persimmon and 0.970~0.993 for pears. 2. It was possible to grade fruits by color with the area weighted mean gray values(AWMGV) based on the mean gray valves of direct image and the compensated values of reflected image of a fruit, and also possible to sort fruits by size with AF. Accuracies in sizing and color grading ranged over 81.0% ~95.0% and 82.0% ~89.7% respectively as compared with results from sizing by electronic weight scale and grading by expert. 3. The blurring effect on the sizing and color grading depending on conveying speed was identified and regression equations were derived. 4. It was found that errors in sizing and coloring grading due to the change in direction and orientation of Fuji apple on the conveyor were not significant as far as the stem end of apple keeping upward.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.513-520
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• 2000

An integrated grader which measures soluble solid content, color and weight of fresh apples was developed by NAMRI. The prototype grader consists of the near infrared spectroscopy and machine vision system. Image processing system and an algorithm to evaluate color were developed to speed up the color evaluation of apples. To avoid the light glare and specular reflection, an half-spherical illumination chamber was designed and fabricated to detect the color images of spherical-shaped apples more precisely. A color revision model based on neural network was developed. Near-infrared(NIR) spectroscopy system using NIR reflectance method developed by Lee et al(1998) of NAMRI was used to evaluate soluble solid content. In order to observe the performance of the grader, tests were conducted on conditions that there are 3 classes in weight sorting, 4 classes in combination of color and soluble solid content, and thus 12 classes in combined sorting. The average accuracy in weight, color and soluble solid content is more than about 90 % with the capacity of 3 fruits per second.

• 한국컴퓨터정보학회논문지
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• 제13권6호
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• pp.155-162
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• 2008

과일의 품질은 여러가지 파라미터에 의해 측정되며, 크기를 측정하기 위한 선과시스템은 회전 드럼식 방식이 사용되며 크기 등급을 선별할 때 과실의 손상이 발생된다. 또한, 당도측정을 위해 사용되는 광검출기는 고가의 선별장비 비용을 초래한다. 제안한 시스템에서는 과일의 특징을 추출하기 위해 3대의 카메라를 이용하였으며, 과일 선별을 위해부피와숙성도정보를사용하므로당도 자체는 측정할 수없지만색상과파손의정보를검출할수있으므로 고해상도의 디지털영상이 필요치 않아 저렴한 비용으로 선과시스템을 개발하였다. 제안한 시스템의 성능평가를 위해 인간의 시각판단과 비교하여 샘플을 분류한 결과 약 96.7%의 정확도를 나타내었다.

• Journal of Biosystems Engineering
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• 제24권3호
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• pp.267-274
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• 1999

An internet and network based software and related interface have been developed, which can remotely control and manage an on-site operating system. Developed software modules were composed of two parts: monitoring/management modules and control/diagnosis modules were developed for the network status, warehouse, production and selling status. Modules of control with diagnosis were developed for the on-site operating system and interface. Each module was integrated and the whole modules have been tested with an automatic mushroom grading/sorting system which was built in a laboratory. Developed software modules worked successfully without any uncommon situations such as system down caused by the software or data transfer error. Each software module was developed independently in order to apply easily to other existing on-site systems such as rice processing centers, fruit and vegetable sorting, packaging and distribution centers scattered over the country.

• Journal of Biosystems Engineering
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• 제17권4호
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• pp.354-362
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• 1992

This study was intended to examine feasibility of sizing and color grading of Fuji apple with black/white image processing system, to develop a device with which the whole surface of an apple could be captured by one camera, and to develop an algorithm for a high speed sorting. The results are summarized as follows : 1. The black/white image processing system used in this study showed a maximum error of 1.3% in area measurement with a reference figure while the focusing point of camera and location of the reference figure were changed within a certain range. 2. As the result of evaluating four automatic image segmentation algorithms with apple images, Histogram Clustering Method was the best in terms of computation time and accuracy. 3. The fast algorithm for analyzing size and coloration of apple was developed. 4. The whole surface of an apple could be captured in an image frame with two mirrors installed on the both sides of the sample. The total area of the image representing the whole surface showed a correlation of 0.995 with the weight of apple. 5. The gray level when a particular band pass filter was mounted on the camera showed high correlation with 'L' and 'a' values of Hunt color scale and could represent the coloration of apple.