• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.399-406
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• 2023

In this study, we propose a ripe tomato bunch localization method based on convolutional neural networks, to be applied in robotic harvesting systems. Tomato images were obtained from a smart greenhouse at the Rural Development Administration (RDA). The sample images for training were extracted based on tomato maturity and resized to 128 × 128 pixels for use in the classification model. The model was constructed based on four-layer convolutional neural networks, and the classes were determined based on stage of maturity, using a Softmax classifier. The localization of the ripe tomato bunch region was indicated on a class activation map. The class activation map could show the approximate location of the tomato bunch but tends to present a local part or a large part of the ripe tomato bunch region, which could lead to poor performance. Therefore, we suggest a recursive method to improve the performance of the model. The classification results indicated that the accuracy, precision, recall, and F1-score were 0.98, 0.87, 0.98, and 0.92, respectively. The localization performance was 0.52, estimated by the Intersection over Union (IoU), and through input recursion, the IoU was improved by 13%. Based on the results, the proposed localization of the ripe tomato bunch area can be incorporated in robotic harvesting systems to establish the optimal harvesting paths.

• Mycobiology
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• v.31 no.1
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• pp.54-56
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• 2003

Perforated vinyl mulching technique was performed on Pleurotus sajor-caju beds to assess fruitbody formation. Individual fruitbody of P. sajor-caju was transformed into bunch type on vinyl mulching bed. It was effective to grow the mushroom without waterlogging and abortion of small pins on the beds as well as hygienical bed management. A bunch showed 79 fruitbodies and 225 g of weight. Available site for fruiting was reduced up to 20% in comparison of 100% for conventional bed. The color of fruitbody turned on brownish white from treated vinyl mulching bed.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.101-101
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• 2022

Schisandra chinensis is a fruit which is called Omija in South Korea. The Korean word Omija means "five flavors" (sweet, spicy, sour, bitter, and salty). The aim of his study was to investigate the correlation between growth characteristics and lignans (gomisin A, gomisin N, schisandrin) contents of Schisandra chinensis. The method for determining lignans was validated by measuring the linearity, limit of detection (LOD), limit of quantification (LOQ), precision and accuracy using UPLC-UV. Growth characteristics of S. chinensis such as number of fruits per fruit bunch, length of fruit bunch, width of fruit bunch, fresh weight of fruit bunch, length of fruit, width of fruit, fresh weight of fruit, fresh weight of 30 fruits, and sugar contents of fruit were measured. From the results of correlation analysis, it was found that the contents of lignans showed a significantly negative correlation with fresh weight and sugar contents of fruit. These results will be used to study for quality control of S. chinensis fruit.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.360-369
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• 2016

In this study, sequential leaching and wet torrefaction were performed to improve the fuel characteristics of empty fruit bunch (EFB). Leaching was carried out at $25{\sim}90^{\circ}C$ for 5~30 min. The highest ash removal efficiency of 55.99% was achieved when leaching was performed at $90^{\circ}C$ for 10 min. The ash removal efficiency was dependent more on leaching temperature than time. Wet torrefaction was carried out at $180{\sim}200^{\circ}C$ for 5~40 min, following the leaching. Most of the inorganic compounds were removed at removal efficiencies of 41.05~63.58% during sequential leaching and wet torrefaction, while silica remained in the biomass. Chloride, calcium, magnesium, and phosphorus showed more than 80% removal efficiencies. The calorific value of EFB increased to 7.96% (4730 kcal/kg) in comparison to the raw material (4390 kcal/kg) when wet torrefaction was performed at $200^{\circ}C$ for 40 min following leaching.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.138-141
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• 2004

본 논문은 EBGM(Elastic Bunch Graph Matching)기법을 이용한 얼굴인식에 대해 다룬다. 대용량 영상 정보에 대해 차원 축소를 이용한 얼굴인식 기법인 주성분기법이나 선형판별기법에서는 얼굴 영상 전체의 정보를 이용하는 반면 본 논문에서는 얼굴의 눈, 코, 입 등과 같은 얼굴 특징점에 대해 주파수와 방향각이 다른 여러 개의 가버 커널과 영상 이미지의 컨볼루션(Convolution)의 계수의 집합(Jets)을 이용한 특징 데이터를 이용한다. 하나의 얼굴 영상에 대해서는 모든 영상이 같은 크기의 특징 데이터로 표현되는 Face Graph가 생성되며, 얼굴인식 과정에서는 추출된 제트의 집합에 대해서 상호 유사도(Similarity)의 크기를 비교하여 얼굴인식을 수행한다. 본 논문에서는 기존의 EBGM방법의 Face Graph 생성 과정을 보다 간략화 한 방법을 이용하여 얼굴인식 과정에서 계산량을 줄여 속도를 개선하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.155.1-155.1
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• 2014

Bunch compressor (BC)는 4세대 방사광가속기가 요구하는 매우 짧은 길이의 전자빔을 만들기 위해서 제작된다. 4개의 이극전자석을 이용하여 에너지에 따른 서로 다른 경로차이를 발생시켜 전자빔을 압축할 수 있다. 중간에 위치한 2개의 이극전자석은 전자빔의 길이를 최적화하기 위하여 전자빔에 수직방향으로 가변된다. 전자빔의 궤도와 진공용기 중심을 동일하게 가져가기 위해 이극전자석 진공용기 사이에는 밸로즈를 사용하였다. BC 진공용기의 요구 압력은 Pave < $5{\times}10^{-7}mbar$이며, 4개의 이온펌프(60 L/s)를 이용하여 진공 배기한다. BC 진공용기 전체 길이는 대략 16 m이며, 전자빔과 진공용기 내부 표면 거칠기와의 상호작용에 의한 Wakefield 효과를 줄이기 위해 거칠기는 Ra <250 nm 이하로 제작하였다. 본 논문에서는 현재까지 진행된 BC 진공용기 시제품 제작 현황에 대하여 보고하고자 한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.6
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• pp.759-764
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• 2005

In this paper we describe a face recognition using EBGM(Elastic Bunch Graph Matching) method. Usally, the PCA and LDA based face recognition method with the low-dimensional subspace representation use holistic image of faces, but this study uses local features such as a set of convolution coefficients for Gabor kernels of different orientations and frequencies at fiducial points including the eyes, nose and mouth. At pre-recognition step, all images are represented with same size face graphs and they are used to recognize a face comparing with each similarity for all images. The proposed algorithm has less computation time due to simplified face graph than conventional EBGM method and the fuzzy matching method for calculating the similarity of face graphs renders more face recognition results.

• Nuclear Engineering and Technology
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• v.56 no.10
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• pp.4237-4246
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• 2024

Using strong electromagnetic fields generated by lasers to interact with electrons for precise diagnosis and manipulation of electron beams represents a recent focal point in accelerator technology. This approach surpasses the limitations of conventional RF technology, such as low electric field gradients and timing jitters, effectively enhancing the accuracy of ultrafast electron beam diagnostics and manipulations. As demands for precision continue to rise, the precise diagnosis of crucial parameters of ultrafast electron beams remains challenging. This study delves into the electromagnetic behavior of THz-driven devices and proposes an all-optical method utilizing single-cycle THz radiation to compress and characterize a 3 MeV electron beam. Particle tracking simulations demonstrate an astonishing compression effect, reducing the bunch length from 54.0 fs to 4.3 fs, and achieving sub-femtosecond bunch length measurement resolution. Moreover, when combined with an orthogonal THz streak camera, this method shows even greater potential in multi-bunch scenarios.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.46-55
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• 2016

The microcrystalline cellulose (MCC) was prepared from oil palm biomass, empty fruit bunch (EFB) for increasing the usability of EFB. The morphological, physical and chemical properties of MCC made from EFB were evaluated by comparing with those of the commercial MCC obtained from AVICEL. The EFB-MCC had the wider distribution in particle size and there were many small particles around $10{\mu}m$. There were no significant differences in the cellulose crytallinity and the chemical composition between EFB-MCC and AVICEL-MCC. The properties of tablet samples made by the common direct compression process were evaluated depending on the types of MCC and the compression pressure during tablet making process. The tablet made of EFB MCC showed the higher compressed structure, which resulted in the less disintegration by the water soaking treatment than those made of Avicel-MCC. The results of this study showed that the EFB-MCC could be utilized as one of the commercial MCC.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1084-1091
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• 2012

Xylooligosaccharides are functional foods mainly produced during the hydrolysis of xylan by physical, chemical, or enzymatic methods. In this study, production of xylobiose was investigated using oil palm empty fruit bunch fiber (OPEFB) as a source material, by chemical and enzymatic methods. Xylanase-specific xylan hydrolysis followed by xylobiose production was observed. Among different xylanases, xylanase from FXY-1 released maximum xylobiose from pretreated OPEFB fiber, and this fungal strain was identified as Aspergillus terreus and subsequently deposited under the accession Number MTCC- 8661. The imperative role of lignin on xylooligosaccharides enzymatic synthesis was exemplified with the notice of xylobiose production only with delignified material. A maximum 262 mg of xylobiose was produced from 1.0 g of pretreated OPEFB fiber using FXY-1 xylanase (6,200 U/ml) at pH 6.0 and $45^{\circ}C$. At optimized environment, the yield of xylobiose was improved to 78.67 g/100 g (based on xylan in the pretreated OPEFB fiber).