• Journal of Biosystems Engineering
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• 제25권3호
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• pp.227-232
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• 2000

A natural air in-bin grain dryer with a grain circulator was developed for on farm use. Natural air drying test for rough rice was carried out to evaluate drying rate, uniformity of moisture content distribution in grain bed and energy consumption. It took 10 days to dry 8 ton of paddy rice from 21.9%(w.b) of moisture contents to 16.7%(w.b), by prototype dryer and the average drying rate was 0.52%/day. The uniformity of moisture content after drying was superior to a conventional natural air dryer in which grains were not mixed during drying periods. The dryer performance evaluation index was 738.3kJ/(kg.water), which was more effective than that of grain circulation type hot air dryer(3,500∼5,000 kJ/kg.water)

• Applied Biological Chemistry
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• 제14권3호
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• pp.221-227
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• 1971

수원 213, 수원 214, 진흥 및 팔달의 한계수량을 각엽위엽의 한계 수량으로부터 계산하였다. 한계수량의 패턴이 각엽의 백분을 기여도에 따라 IR 667계통은 상위엽 의존형인 반면 진흥과 팔달은 하위엽 의존형으로 구분할 수 있었다. 이러한 패턴은 각기 조기노화 및 내음성과 관련될 것으로 추정되었다. 한계수량과 실수랑을 비교한 결과 초형이 비교적 불량한 진흥과 팔달은 보다 더 한계수량에 미달하였다. 한계수량이 갖는 영양생리 및 육종에 있어서의 의의를 검토하였으며 한계수량 측정방법도 논의하였다.

• 한국작물학회지
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• 제65권4호
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• pp.303-313
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• 2020

본 연구는 단조로운 국내 벼 품종의 입형을 다양화하기 위하여 초장립종 자포니카 품종을 활용해 그 특성을 국내 벼 품종에 도입함으로써 입형이 다양한 새 품종을 개발하려는 기초 육종연구의 일환으로 수행되었다. 입형 다양화를 위하여 세장형 자포니카 벼 품종인 Langi와 입형이 극단적으로 원형에 가까운 자포니카형 조생자도를 교배하여 유전분석 및 QTL 탐색을 위한 mapping 집단을 육성하였고, 이를 이용하여 입형 관련 형질의 상관분석, QTL 분석, validation test 및 탐색된 QTL 효과를 검정한 결과는 다음과 같다. 1. 조생자도와 Langi 조합의 교배립을 생산하여 F₂ 집단을 육성하였고 출수 일수를 고려하여 최종 265 개체를 선발·수확하여 주요 형질에 대한 조사와 QTL 분석에 이용하였다. 2. 육성된 mapping집단의 입형 관련 형질들은 종자 길이에 대해 종자 장폭비(0.89)와 천립중(0.69)이 상대적으로 높은 상관계수를 나타냈고, 종자폭에 대해서는 종자 길이(-0.47)와 장폭비(-0.82)가 음의 상관을 나타냈으며 종자두께(0.43)는 정상관을 보였다. 3. QTL 분석 결과 종자 길이와 관련하여 벼 5번 염색체에서 PVE 값이 20.31%인 qGL5와 7번 염색체에서 PVE 값이 각각 36.07%와 26.11%인 qGW5와 qGW7을 탐색하였다. qGL5는 세장형인 Langi로부터 유래하였으며, 두 QTL(qGW5, qGW7)은 원형인 조생자도로부터 유래하였다. 4. Validation test결과 Langi는 자포니카형 벼(qsw5_N)에서는 매우 드문 qSW5형 대립유전자를 가지고 있으며 이것은 qGL5와 함께 작용하여 집단내에서 종자 길이신장에 관여했을 것으로 추정된다. 5. 탐색 QTL의 효과는 qGL5 (+)와 qGW5:qGW7 조합에서 중원형, 장원형, 세장형 등 입형의 변이가 다양하게 나타났는데 Langi가 자포니카 생태형이란 점과 QTL의 효과가 증명되어 MAS활용이 가능하다는 점 등 입형 다양화를 위한 육종사업에서의 효과 및 활용도가 다양할 것으로 생각된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.865-869
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• 1997

In recent years, there has been increasing demand of ultra-fine grain graded cemented tungsten carbide material with high hardness and toughness which is used as high speed cutting tool for development in semiconductor, electronics and die/mold industry, which bring into limelight high-precision, high-efficient machining of sculptured surfaces. This paper deals with the performance of variation in the ultra-fine grain graded cemented tungsten carbide material such as grain size, hardness and density varied according to the volume of added elements, Co or TaC, and he changing of mixing, sintering process. Also, the performance of developing material with uniformed grain size of 0.5${\mu}{\textrm}{m}$ is compared with other domestics' & foreign companies' with analyzing and cutting performance testing.

• 한국작물학회지
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• 제65권4호
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• pp.294-302
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• 2020

등숙기간 동안의 온도에 따라서 동일한 출수 후 일수가 경과하더라도 출수 후 적산온도가 달라져 종실의 등숙단계가 달라지기 때문에 수발아에 영향을 줄 수 있는 종실의 특성이 달라지게 된다. 그렇기 때문에 수발아 검정을 위한 처리 시점은 출수 후 일수가 아닌 출수 후 특정 적산온도에 조건을 맞춰 시험을 진행해야 한다. 한편 수발아 발생은 등숙기간 동안의 온도에 따라서 크게 달라진다. 이에 따라서 발생하는 전분립의 구조, 전분함량 및 ABA함량의 변이 등은 수발아 발생에 영향을 줄 것으로 생각되며, 특히 고온등숙 시 수발아 발생율의 증가와 종실 전분립의 구조, 유리당 함량 등 종실 이화학적 특성 변이와의 관계에 대한 추가적인 검토가 필요할 것으로 생각된다. 또한 고온등숙시 수발아 발생율이 증가하기 때문에 등숙기 고온에 노출되지 않도록 이앙시기를 조절하여 수발아 발생위험을 감소시켜야 한다.

• 소성∙가공
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• 제11권5호
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• pp.439-446
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• 2002

This study presents a new computational model to analyze the grain deformation in a polycrystalline aggregate in a discrete manner and based directly in the underlying physical micro-mechanisms. When scaling down a metal forming process, the dimensions of the workpiece decrease but the microstructure of the workpiece remains the similar. Since the dimensions of the workpiece are very small, the microstructure especially the grain size will play an important role in micro forming, which is called size effects. As a result, specific characteristics have to be considered for the numerical analysis. The grains and grain boundary elements are introduced to model individual grains and grain boundary facets, respectively, to consider the size effects in the micro forming. The constitutive description of the grain elements accounts for the rigid-plastic and the grain boundary elements for visco-elastic relationships. The capability of the proposed approach is demonstrated through application of grain element and grain boundary element in the micro forming.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.279-279
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• 2022

Rice is 34% of the world's population used as a staple food. But the world population is increasing. Food security is not well protected. Improving cultivar development can address food security. Quantitative trait locus (QTL) mapping is a statistical analysis using both phenotypic and genotypic dates. The purpose of QTL mapping is to determine a gene. Increasing grain size is a way to increase yield in rice. Grain size-related genes were mapped using CNDH population obtained by cross-breeding Cheongcheong (Indica) and Nagdong (Japonica) through anther culture. Grain harvested from experimental field of Kyungpook National University in Gunwi in 2021. Genes related to grain length were detected between RM5964-RM12285, RM20924-RM20967 in chromosome 1, 7. LOD score is 5.88 and 5.6. Genes related to grain width was detected between RM289-RM18130 in chromosome 5. LOD score is 4.57. Genes related to grain length/width ratio were detected between RM5459-RM3482, RM5699-RM1211 and RM3838-RM3381 in chromosome 1, 2, 5. LOD score is 3.75, 3.14 and 3.41. 4 genes was detected in chromosome 1 and 2 genes was detected in chromosome 2 and 7 genes was detected in chromosome 5. 2 genes related to grain shape and quality were detected. 4 genes related to grain length were detected. 4 genes related to grain size were detected. 1 gene related to grain size and weight was detected. 2 genes related to grain length and weight were detected. By finding the gene related to grain size, it provides food to people threatened by food security and solves the food shortage.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.297-297
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• 2022

Wheat is the staple food crop in the word, but wheat products have a low bioavailability of iron and zinc. So in the developing world, where wheat is a staple food, it suffers from micronutrients deficiency. This study was conducted to generate wheat varieties with enhanced grain Zn and Fe contents. Sixty wheat resource were cultivated over 2 years (2019-2021) in the field of NICS, Jeonju, Republic of Korea, to identify agronomic traits. Wheat grains were ground using grinder and analyzed whole wheat flour protein contents and Fe and Zn contents using ICP-OES. The average contents of Zn and Fe grain were 4.6 mg/100g (2.4~8.8 mg/100g) and 4.5 mg/100g (2.4~7.9 mg/100g), respectively. The contents of Fe and Zn in the wheat grain had a positive correlation with the protein content of whole wheat flour, but there was no correlation with heading date (4.22~5.27) and the thousand kernel weight (21.3~57.5 g). Although there was year variation, six resources with high contents of Fe (>5.2 mg/100 g) and Zn (>5.3 mg/100 g) grain in 2 years were selected. These results provide information for selecting breeding materials for biofortified wheat, and further studies on germplasms genetic variations and bioavailability are needed.

• Metals and materials international
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• 제24권6호
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• pp.1412-1421
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• 2018

Cold-expanded austenitic high nitrogen steel (HNS) was subjected to investigate the effects of grain size on the stress-controlled high cycle fatigue (HCF) as well as the strain-controlled low cycle fatigue (LCF) properties. The austenitic HNSs with two different grain sizes (160 and $292{\mu}m$) were fabricated by the different hot forging strain. The fine-grained (FG) specimen exhibited longer LCF life and higher HCF limit than those of the coarse-grained (CG) specimen. Fatigue crack growth testing showed that crack propagation rate in the FG specimen was the same as that in the CG specimen, implying that crack propagation rate did not affect the discrepancy of LCF life and HCF limit between two cold-expanded HNSs. Therefore, it was estimated that superior LCF and HCF properties in the FG specimen resulted from the retardation of the fatigue crack initiation as compared with the CG specimen. Transmission electron microscopy showed that the effective grain size including twin boundaries are much finer in the FG specimen than that in the CG specimen, which can give favorable contributions to strengthening.

• Journal of Biosystems Engineering
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• 제41권4호
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• pp.408-417
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• 2016

Purpose: Yield monitoring systems are an essential component of precision agriculture. They indicate the spatial variability of crop yield in fields, and have become an important factor in modern harvesters. The objective of this paper was to review research trends related to yield monitoring sensors for grain crops. Methods: The literature was reviewed for research on the major sensing components of grain yield monitoring systems. These major components included grain flow sensors, moisture content sensors, and cutting width sensors. Sensors were classified by sensing principle and type, and their performance was also reviewed. Results: The main targeted harvesting grain crops were rice, wheat, corn, barley, and grain sorghum. Grain flow sensors were classified into mass flow and volume flow methods. Mass flow sensors were mounted primarily at the clean grain elevator head or under the grain tank, and volume flow sensors were mounted at the head or in the middle of the elevator. Mass flow methods used weighing, force impact, and radiometric approaches, some of which resulted in measurement error levels lower than 5% ($R^2=0.99$). Volume flow methods included paddle wheel type and optical type, and in the best cases produced error levels lower than 3%. Grain moisture content sensing was in many cases achieved using capacitive modules. In some cases, errors were lower than 1%. Cutting width was measured by ultrasonic distance sensors mounted at both sides of the header dividers, and the errors were in some cases lower than 5%. Conclusions: The design and fabrication of an integrated yield monitoring system for a target crop would be affected by the selection of a sensing approach, as well as the layout and mounting of the sensors. For accurate estimation of yield, signal processing and correction measures should be also implemented.