• 한국작물학회지
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• 제53권spc호
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• pp.72-77
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• 2008

This study was carried out to determine the response of the rice yield and grain quality by rice leaf folder (RLF, Cnaphalocrocis medinalis G.) and identify the damages caused by different transplanting dates, nitrogen amounts and chlorophyll amounts (SPAD value) of rice leaf. As the damage degree of RLF was getting severer, the ripened grain rate and 1000-grain weight were decreased and due to the increasing of chalky rice rate the rate of head rice was reduced. Therefore, the yield of head rice was decreased by 36% in heavily damaged rice plant. Among the physicochemical characteristics, protein content of rice grain was increased but amylose content was reduced, consequently, the palatability was deteriorated in heavily damaged rice by RLF. The degree of damage of RLF was getting serious as transplanting date was delayed and as the amount of nitrogen was increased. In the relationship between the SPAD value and the damage degree of RLF, as the SPAD value was increased by nitrogen fertilizing, the damage degree was also increased exponential functionally.

• 한국식품영양학회지
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• 제13권1호
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• pp.21-27
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• 2000

In order to investigate the changes of rice qualities during 4 years storage of paddy in warehouse of normal temperature condition. As storage period go by, head ratio was deduced and broken rice was increased according as a change of temperature during the long term storage. A color of rice was became more dark gray than that of entering time as L value was decreased from 64.07 to 61.62 a 4 years late. As a results of studies on the cooking quality of milled rice, water uptake ratio and expanded volume were increased in proporation to storage period, wherease total solids and iodine blue value were decreased. In the characteristic of texture of cooked rice, viscosity/hardness ratio(-H/H) had a decreasing tendency, while adhesiveness and cohesiveness increased with increased storage time. The qualities of cooked milled rice studied were sensory attributies of odor, taste, stickiness and appearance which were evaluvated by multiple comparsion method. The sensory results showed that all of descriptions were deterirated with a increased storage period. The taste and stickiness were changed from good score to bad score a 2 years later.

• 한국작물학회지
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• 제53권spc호
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• pp.44-46
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• 2008

경북지역에서 생산 유통되는 브랜드 쌀의 품질 분석을 통해 고품질 쌀 생산의 기초 자료로 활용하고자 하였으며, 분석시료로는 경북 시군에서 추천한 2006-2007년도 브랜드 쌀 26종을 사용하였다. 단백질 함량은 6.5%이하가 46.2% (12종), 6.6%-7.0%는 23.1%(6종)로 비교적 낮아 단백질 함량은 양호하였다. 완전립율은 95% 이상이 7.7%(2종), 90-94%는 15.4%(4종)이었으며 89% 이하가 76.9%(20종)로 품질이 다소 낮았으며 분상질립은 다소 높아 완전립율과 분상 질립 개선이 필요하다. DNA 분석에 의한 품종 혼입율 분포는 1-10%가 46.2%(12종), 11-20%는 34.6%(9종)로서 순도 80% 이상이 80.8%로서 매우 양호하였다.

• 한국작물학회지
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• 제49권3호
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• pp.199-206
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• 2004

Typhoon "MAEMI", happened in September 2003, hit the great damage to Gyeongnam province area. Especially, rice plant was lodged or severe leaf damage was caused. This study was conducted to find out the extents of leaf damage among different rice cultivars, and to evaluate rice yield and eating quality due to leaf damage after typhoon. Rice cultivars torn off over half of the flag leaf length (FLL) were one medium-late maturing cultivar (Donginl), medium maturing cultivar (Yeonganbyeo), eight early maturing cultivars (Samcheonbyeo, Jounghwnbyeo, Munjangbyeo, Taebongbyeo, Odaebyeo, Samhaegbyeo, Sobaegbyeo, Sinunbongbyeo), two long-il type cultivars (Samgangbyeo, Namcheonbyeo), and three special use cultivars (Heukseonchalbyeo, Jinbuchalbyeo, Yangjobyeo). Cultivars torn off below 1/10 FLL were eight medium-late maturing cultivars (Chucheongbyeo, Daecheongbyeo, Saechu cheongbyeo, Donganbyeo, Daeyabyeo, Hwamyeongbyeo, 방eongsanbyeo, Dongjinbyeo) and two medium maturing cultivays (Donghaebyeo, Gumobyeo2). The rest cultivars were tore off by 1/10∼1/2 ELL. In yield components, the longer was flag leaf damage, the lower was ripened grain ratio, grain weight and brown/rough rice ratio, which was severly impacted to late than to ordinary season cultivation. However, rice yield did not decrease up to tearing by 1/10 ELL. Head rice ratio decreased from flag leaf tearing over 1/10 ELL in late season cultivation. The longer was flag leaf damage, the lower was eating quality, which could not show significantly different.

• 한국식품과학회지
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• 제48권5호
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• pp.521-524
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• 2016

쌀밥의 조직감 측정시 가장 보편적으로 사용되는 텍스처 프로파일 분석(TPA)에 있어서, 모방적기기인 texture analyser를 사용하여 측정조건, 즉 압착율과 탐침이동속도를 달리하면서 4종류의 즉석쌀밥 시료들에 대한 경도, 점착성, 응집성, 씹힘성 및 탄성을 측정하였다. 4종류의 즉석쌀밥 시료들은 압착율과 탐침이동속도가 달라짐에 따라, 각각의 조직감 특성에 있어서 시료들 사이에 유의적인 차이를 보이거나 보이지 않는 변화를 보였다. 또한, 다섯가지 조직감 특성을 모두 고려하여 군집분석을 수행했을 경우에도 측정조건에 따라서 4종류 시료들이 서로 다르게 그룹화되는 것을 볼 수 있었다. 더불어, 쌀밥의 조직감 평가시 사용되는 '점착성/경도'값도 측정조건에 따라 4종류 시료들이 서로 다른 값을 보여주었다. 이들 결과를 토대로, 쌀밥의 조직감 측정시 쌀밥의 관능적 조직감 특성을 객관적으로 언급할 목적으로 기기적 측정을 수행한다면, 여러 분석을 통해 관능검사 결과와 가장 부합하는 측정 조건을 선택하는 것이 필요하며, 특정한 기기적 측정조건을 설정할 경우 실험목적에 따라 여러 특성을 고려하여 적합한 측정조건을 설정하는 것이 매우 중요하다 하겠다.

• 한국작물학회지
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• 제53권4호
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• pp.347-352
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• 2008

전북 유통브랜드 쌀과 국내 및 수입쌀과의 품질특성을 비교한 결과를 요약하면 다음과 같다. 1. 전북유통브랜드 쌀의 품종은 일미가 대부분을 차지하였고 그 외 신동진, 일본계 품종, 여러 품종이 섞인 일반계 품종이었다. 2. 전북우수브랜드와 전북 외 우수브랜드 쌀의 시기별 품질변화에서 완전미율과 맛에 영향을 주는 수분함량, 식미값 등은 큰 차이가 없었으나 평균 완전미율은 전북 우수브랜드 쌀 95.3%, 전북 외 우수브랜드 쌀 94.2% 전북일반브랜드 쌀 89.1%였으며 전북우수브랜드 쌀과 전북 외 우수 브랜드 쌀은 동등한 품질을 나타내었다. 3. 국내쌀과 수입쌀의 외관특성 비교에서 국내쌀의 장폭 비는 1.87로 미국산 수입쌀이나 태국산 수입쌀의 2.24, 3.33 보다 작았으며 수입(중국)쌀 장폭비는 1.84로 국내쌀과 같은 단립종의 특성을 나타내었다. 4. 국내쌀의 단백질함량은 6.2%로 미국산 수입쌀 6.1%와 비슷한 함량을 나타내었고 완전미 함량도 90%이상이었다. 5. 전분호화 특성을 알아 본 결과 최고점도는 중국산 찐 쌀이 가장 낮았고 치반점도, 최종점도 등은 태국산 수입쌀이 가장 높았다. 6. 국내쌀과 수입쌀을 비교한 취반특성은 취반미의 식미를 결정짓는 요인 중의 하나인 부착성(Ad)/경도(H)의 비가 국내쌀과 미국산 수입쌀이 높았으며 태국산 수입쌀이 가장 낮았다. 7. 국내쌀과 밥쌀용으로 국내에 유통된 수입쌀 비교에서 외형적 형태는 미국산 수입쌀과 차이가 났지만 품질은 동등하였고 중국산 수입쌀과 찐쌀의 품질과는 차이를 나타내었다.

• Journal of Biosystems Engineering
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• 제1권1호
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• pp.15-15
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• 1976

In analyzing the operational characteristics of a rice whitening machine, the internal radial pressure of the machine was measured using strain gage equipment. Changes in cylinder and feed screw configurations, screen type, cylinder speed and counter-pressure levels were examined to determine their impact on the quality and quantity of milled rice and the performance of the machine. The results are summarized as follows: 1. The internal radial pressure in the whitening chamber varied with the surface condition of the grain being processed. During the first or second pass through the machine, pressure was relatively low, reached a maximum after two to three passes with combinations I and II, three to six with combination III and then began to fall. 2. The pitch of the feed screw and the size of the feed gate opening which determine the rate of entry of grain into the whitening chamber, appeared to be the most important factor aff-::cting the degree of radial pressure, quality and quantity of milled rice and the efficiency of the machine. Using a feed screw with a wide pitch (4.8cm), radial pressure was relatively high and head rice recovery ratio \vere quite low. In this case capacity and machine effic?iency were much higher than obtained when using a feed screw with a narrow pitch (2.3cm). Very significant responses in radial pressure, head rice recovery rates and machine capacity were observed with changes in cylinder speed and counter-pressure levels when using the wide pitch feed screw. 3. The characteristics of the screen which surrounds the whitening chamber had an important effect on whitening efficiency. The existence of small protuberances on the original screen resulted in significant increases in both machine capacity and efficiency but without a significant decrease in head rice recovery or development of excessive radial pressure. Further work is required to determine the effects of screen surface conditions and the shape of the cylinderical steel roller on the rate of bran removal, machine efficiency and recovery rates. The size of the slotted perforations 0:1 the screen affects total milled rice recovery. The opening size on the original screen was fabricated to accommodate the round shape of Japonica rice varieties but was not suitable for the more slender Indica type. Milling Indica varieties with this screen resulted in a reduction in total milled rice recovery. 4. An increase in cylinder speed from 380 to 820 rpm produced a positive effect on head rice recovery for all machine combinations at every level of counter-pressure used in the tests. Head rice recovery was considerably lower at 380rpm using a wide screw pitch when compared to the results obtained at speeds from 600 to 820 r.p.m. The effects of cylinder speed On radial pressure, capacity and machine efficiency showed contrasting results, depending on the width of the feed screw pitch. With a narrow feed screw pitch (2.3cm), a direct proportional relationship was observed bet?ween cylinder speed and both radial pressure and machine efficiency. In contrast, using a 4.8 centimeter pitch feed roller produced a series of inverse relationships between the above variables. Based on the results of this study it is recommended when milling Indica type long grain rice varieties that the cylinder speed of the original machine be increased from 500-600 rmp up to a minimum of 800 rpm to obtain a greater abrasive effect between the grain and the screen. The pitch of the feed screw should be also reduced to decr?ease the level of internal radial pressure and to obtain higher machine efficiency and increased quality of milled rice with increased cylinder speeds. Further study on the interaction between cylinder speed and feed screw pitch is recommended. 5. An increase in the counter pressure level produced a negative effect On the head rice recovery with an increase in radial pressure, capacity, and machine efficiency over all combinations and at every level of cylinder speed. 6. Head rice recovery rates were conditioned primarily by the pressure inside the whitening chamber. According to the empirical cha racteristics curve developed in this study, the relationships of head rice recovery ($Y_h$) and machine capacity ($Y_c$/TEX>) to internal radial pressure ($X_p$) followed an inverse quadratic function and a linear function respectively: $$Y_h^\Delta=\frac{1}{{1.4383-0.2951X_p^\ast+0.1425X_p^{\ast\ast}}^2} , (R^2=0.98)$$$$Y_c^\Delta=-305.83+374.37X_p^{\ast\ast}, (R^2=0.88)$$The correlation between capacity and power consumption per unit of brown rice expressed in the following exponential function: $$Y_c^\Delta=1.63Y_c^{-0.7786^\{\ast\ast}, (R^2=0.94)$$These relationships indicate that when radial pressure increases above a certain range (1. 6 to 2.0 kg/$cm^2$ based On the results of the experiment) head ricerecovery decrea?ses in a quadratic relation with a inear increase in capacity but without any decrease in power consump tion per unit of brown rice. On the other hand, if radial pressure is below the range shown above, power consumption increases dramatically with a lin?ear decrease in capacity but without significant increases in head rice recovery. During the operation of a given whitening machine, the optimum radial pressure range or the correct capacity range should be selected by controlling the feed rate and/or counter-pressure keeping in mind the condition of the grain, particulary the hardness. It was observed that the total number of passes is related to radial pessure level, feed rate and counter-pressure level. The higher theradial pressure the fewer num?ber of pass required but with decreased head rice recovery. In particular, when using high feed rates, the total number of passes should be increased to more than three by reducing the counter-pressure level to avoid decreaseases in head rice recovery (less than 65 percent head rice recovery on the basis of brown rice) at every cylinder speed. 7. A rapid rise in grain temperature seemed to have a close relationship with the pressure generated inside the whitening chamber and, subsequently with head rice reco?very rates. The higher the rate of increase, the lower were the resulting head rice recoveries.

• Journal of Biosystems Engineering
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• 제1권1호
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• pp.17-48
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• 1976

In analyzing the operational characteristics of a rice whitening machine, the internal radial pressure of the machine was measured using strain gage equipment. Changes in cylinder and feed screw configurations, screen type, cylinder speed and counter-pressure levels were examined to determine their impact on the quality and quantity of milled rice and the performance of the machine. The results are summarized as follows: 1. The internal radial pressure in the whitening chamber varied with the surface condition of the grain being processed. During the first or second pass through the machine, pressure was relatively low, reached a maximum after two to three passes with combinations I and II, three to six with combination III and then began to fall. 2. The pitch of the feed screw and the size of the feed gate opening which determine the rate of entry of grain into the whitening chamber, appeared to be the most important factor aff-::cting the degree of radial pressure, quality and quantity of milled rice and the efficiency of the machine. Using a feed screw with a wide pitch (4.8cm), radial pressure was relatively high and head rice recovery ratio \vere quite low. In this case capacity and machine effic\ulcorneriency were much higher than obtained when using a feed screw with a narrow pitch (2.3cm). Very significant responses in radial pressure, head rice recovery rates and machine capacity were observed with changes in cylinder speed and counter-pressure levels when using the wide pitch feed screw. 3. The characteristics of the screen which surrounds the whitening chamber had an important effect on whitening efficiency. The existence of small protuberances on the original screen resulted in significant increases in both machine capacity and efficiency but without a significant decrease in head rice recovery or development of excessive radial pressure. Further work is required to determine the effects of screen surface conditions and the shape of the cylinderical steel roller on the rate of bran removal, machine efficiency and recovery rates. The size of the slotted perforations 0:1 the screen affects total milled rice recovery. The opening size on the original screen was fabricated to accommodate the round shape of Japonica rice varieties but was not suitable for the more slender Indica type. Milling Indica varieties with this screen resulted in a reduction in total milled rice recovery. 4. An increase in cylinder speed from 380 to 820 rpm produced a positive effect on head rice recovery for all machine combinations at every level of counter-pressure used in the tests. Head rice recovery was considerably lower at 380rpm using a wide screw pitch when compared to the results obtained at speeds from 600 to 820 r.p.m. The effects of cylinder speed On radial pressure, capacity and machine efficiency showed contrasting results, depending on the width of the feed screw pitch. With a narrow feed screw pitch (2.3cm), a direct proportional relationship was observed bet\ulcornerween cylinder speed and both radial pressure and machine efficiency. In contrast, using a 4.8 centimeter pitch feed roller produced a series of inverse relationships between the above variables. Based on the results of this study it is recommended when milling Indica type long grain rice varieties that the cylinder speed of the original machine be increased from 500-600 rmp up to a minimum of 800 rpm to obtain a greater abrasive effect between the grain and the screen. The pitch of the feed screw should be also reduced to decr\ulcornerease the level of internal radial pressure and to obtain higher machine efficiency and increased quality of milled rice with increased cylinder speeds. Further study on the interaction between cylinder speed and feed screw pitch is recommended. 5. An increase in the counter pressure level produced a negative effect On the head rice recovery with an increase in radial pressure, capacity, and machine efficiency over all combinations and at every level of cylinder speed. 6. Head rice recovery rates were conditioned primarily by the pressure inside the whitening chamber. According to the empirical cha racteristics curve developed in this study, the relationships of head rice recovery ($Y_h$) and machine capacity ($Y_c$/TEX>) to internal radial pressure ($X_p$) followed an inverse quadratic function and a linear function respectively: $$Y_h^\Delta=\frac{1}{{1.4383-0.2951X_p^\ast+0.1425X_p^{\ast\ast}}^2} , (R^2=0.98)$$ $$Y_c^\Delta=-305.83+374.37X_p^{\ast\ast}, (R^2=0.88)$$ The correlation between capacity and power consumption per unit of brown rice expressed in the following exponential function: $$Y_c^\Delta=1.63Y_c^{-0.7786^\{\ast\ast}, (R^2=0.94)$$ These relationships indicate that when radial pressure increases above a certain range (1. 6 to 2.0 kg/$cm^2$ based On the results of the experiment) head ricerecovery decrea\ulcornerses in a quadratic relation with a inear increase in capacity but without any decrease in power consump tion per unit of brown rice. On the other hand, if radial pressure is below the range shown above, power consumption increases dramatically with a lin\ulcornerear decrease in capacity but without significant increases in head rice recovery. During the operation of a given whitening machine, the optimum radial pressure range or the correct capacity range should be selected by controlling the feed rate and/or counter-pressure keeping in mind the condition of the grain, particulary the hardness. It was observed that the total number of passes is related to radial pessure level, feed rate and counter-pressure level. The higher theradial pressure the fewer num\ulcornerber of pass required but with decreased head rice recovery. In particular, when using high feed rates, the total number of passes should be increased to more than three by reducing the counter-pressure level to avoid decreaseases in head rice recovery (less than 65 percent head rice recovery on the basis of brown rice) at every cylinder speed. 7. A rapid rise in grain temperature seemed to have a close relationship with the pressure generated inside the whitening chamber and, subsequently with head rice reco\ulcornervery rates. The higher the rate of increase, the lower were the resulting head rice recoveries.

• 한국작물학회지
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• 제53권3호
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• pp.244-250
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• 2008

도정하지 않은 정조의 81 시료로부터 스펙트럼을 수집하고, 백미 완전미도정수율 예측 희귀모델을 개발하기 위해 검량식을 작성한 결과 스펙트럼을 8 nm 간격으로 지정하고, 1차미분 방법으로 검량식을 작성한 완전미율의 결정계수는 MPLS에서 0.8353, PLS 방법에서 0.8416, PCR에서 0.5277를 나타냈다. 스펙트럼을 20 nm 간격으로 지정하고 1차미분 방법으로 검량식을 작성하였다. 완전미율의 결정계수는 MPLS에서 0.8144, PLS 방법에서 0.8354, PCR에서 0.6809를 나타냈다. 스펙트럼을 8 nm 간격으로 지정하고 2차미분 방법으로 검량식을 작성하였다.완 전미율의 결정계수는 MPLS 방법에서 0.7994, PLS에서 0.8017, PCR에서 0.4473을 나타냈다. 스펙트럼을 20 nm 간격으로 지정하고 2차미분 방법으로 검량식을 작성하였다. 완전미율의 결정계수는MPLS 방법에서 0.8004, PLS에서 0.8493, PCR에서 0.6609을 나타냈다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.261-261
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• 2017

This study was carried out to provide basic data for spreading rice direct seeding by inducing stabilization of seedlings, yield and quality according to sowing times in rice direct seeding cultivation. In 2016, 'Sukwang' was seeded 3 times by 10 days interval on May. 10, 20, 30 and 6kg/10ha of seeding rate respectively in Iksan. In summary, the number of rice seedling establishment was higher than the optimum seedling establishment level at all sowing periods and the seeding rate was better as the sowing period was delayed. Weed development by sowing was the highest at early sowing, May 10, and decreased at late sowing. Heading dates were delayed by 3days for sowing on May 10, 7days for sowing on May 20, and 11 days on sowing on May 30. Rice yield increased with the delay sowing time and compared to the transplanting. It was 84% in sowing on May 10, 94% in sowing on May 20, and 99% in sowing on May 30. In addition, head rice ratio and head rice yield increased according to delayed of seedling.