• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권1호
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• pp.347-370
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• 2019

In the computer-aided detection (CAD) system of pulmonary nodules, a high false positive rate is common because the density and the computed tomography (CT) values of the vessel and the nodule in the CT images are similar, which affects the detection accuracy of pulmonary nodules. In this paper, a method of automatic detection of pulmonary nodules based on multi-scale enhancement filters and 3D shape features is proposed. The method uses an iterative threshold and a region growing algorithm to segment lung parenchyma. Two types of multi-scale enhancement filters are constructed to enhance the images of nodules and blood vessels in 3D lung images, and most of the blood vessel images in the nodular images are removed to obtain a suspected nodule image. An 18 neighborhood region growing algorithm is then used to extract the lung nodules. A new pulmonary nodules feature descriptor is proposed, and the features of the suspected nodules are extracted. A support vector machine (SVM) classifier is used to classify the pulmonary nodules. The experimental results show that our method can effectively detect pulmonary nodules and reduce false positive rates, and the feature descriptor proposed in this paper is valid which can be used to distinguish between nodules and blood vessels.

• 분석과학
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• 제35권4호
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• pp.181-188
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• 2022

This paper describes a comparative analysis of yeast cell viability at exponential and stationary growth phases using multiple conventional techniques and statistical tools. Overall, cellular responses to various viability assays were asynchronous. Results of optical density measurement and direct cell counting were asynchronous both at exponential and stationary phases. Proliferative capacity measurement using SP-SDS indicated that cells at the end of the stationary phase were proliferative as much as exponentially growing cells. Metabolic activity assays using two different dyes concluded that the inside of cells at stationary phase is slightly less reducing compared to that of exponentially growing cells, implying that the metabolic activity imperceptibly declined as cells were aged. These results will be helpful to understand the details of yeast cell viability at exponential and stationary growth phases.

• 한국축산시설환경학회지
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• 제15권1호
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• pp.37-50
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• 2009

본 연구결과는 출하돈의 도체품질 향상과 품질인증 프로그램 구축을 위한 자료로 활용하기 위하여 2년 동안 53개 농장에서 출하된 248,787두에 대한 도체평가 결과를 모돈수에 의한 경영규모, 육성비육돈 단계의 사육밀도, 수송시간, 출하시점, 비육돈 후기사료 급여비율 및 비육돈사 형태에 따라 도체등급과 PSE 발생율, 도체 근간지방 점수, 근내지방 점수, 피하지방 점수 및 육탄력성 점수에 미치는 영향을 분석한 결과이며 요약하면 다음과 같다. 1. 양돈장 경영규모는 도체등급에 영향을 미치며, 경영규모가 커질수록 좋은 등급을 나타내었으나, PSE 출현율은 경영규모에 따른 차이가 인정되지 않았다. 도체 근간지방 점수, 근내지방 점수, 피하지방 점수 및 육탄력성 점수는 양돈장 경영규모에 따라 일정한 차이를 나타내지 않았다. 2. 육성비육돈사 사육밀도는 도체등급에 영향을 미치며, 중간 밀도에서 좋은 등급을 나타내었으나, PSE 발생율은 낮은 밀도에서 오히려 높게 나타났다. 도체 근간지방 점수와 근내지방 점수 및 육탄력성 점수는 중간 밀도에서 우수하게 나타났으나 피하지방 점수는 사육밀도에 의한 차이가 없었다. 3. 출하돈의 수송시간에 의한 도체등급 차이는 인정되지 않았으며, PSE 발생율 역시 수송시간에 의한 차이는 없었다. 그러나 수송시간은 도체 육질점수에 영향을 미치며, 1시간을 초과한 수송이 근간지방 점수와 근내지방 점수, 피하지방 점수 및 육탄력성 점수 모두 우수한 것으로 나타났다. 4. 출하시점은 출하후 계류를 통한 도축전 휴식과 관련되는데, 출하시점은 도체등급과 PSE 발생율에 영향을 미치지 않는 것으로 나타났다. 도체 근간지방 점수, 근내지방 점수 및 육탄력성 점수는 오전 10시 이전 출하가 우수한 것으로 나타났으나, 피하지방 점수는 차이가 없었다. 5. 비육돈 후기사료 급여비율 차이에 의한 도체등급 차이는 인정되지 않았으나, PSE 발생율은 후기사료 21% 이상 급여가 높은 것으로 나타났다. 도체 근간지방 점수와 근내지방 점수는 후기사료를 21% 이상 급여한 경우가 우수하게 나타났으며, 피하지방 점수는 후기사료를 20% 이내 급여가 우수하였으나, 육탄력성 점수는 비육후기사료 급여비율에 의한 차이는 인정되지 않았다. 6. 비육돈사 형태에 따른 도체등급의 차이는 무창돈사가 우수하게 나타났으나, PSE 발생율 또한 무창돈사가 높았다. 도체 근간지방 점수와 근내지방 점수는 비육돈사 형태에 의한 차이는 없었으나, 피하지방 점수와 육탄력성 점수는 개방돈사가 우수한 것으로 나타났다. 이상의 결과를 종합해 보면, 양돈장 관리시스템 및 도축전 취급이 출하돈의 도체등급과 육질점수에 영향을 미치는 구체적인 내용들을 확인할 수 있었다. 따라서 양돈장 관리시스템과 관련된 각종 환경요인과 관리요인 및 도축전 취급과 관련된 인자들에 대한 세심한 관리를 통하여 스트레스 최소화와 동물복지 향상으로 도체품질 개선과 소비자를 위한 품질인증 시스템을 구축하여야 할 것으로 사료된다.

• 한국결정성장학회지
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• 제8권1호
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• pp.29-35
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• 1998

고품질의 6H-SiC 단결정을 성장하기 위하여 기판, 원료 및 성장에 사용되는 도가니에 대한 고순도 처리공정을 통하여 고순도화하여 결정성장을 시행하였다. 특히, 원료에 대해서는 순화처리전후의 XRD 분석을 행하여 고순도화된 원료의 상태를 확인하였다. 성장된 6H-SiC 단결정의 크기는 직경이 33mm, 길이는 11mm이었고, 기판으로의 사용 및 내부결함에 대한 관찰을 위하여 결정을 절단 및 연마하여 직경 33mm, 두께 0.5mm인 wafer를 제작하였으며, 광학현미경 및 Raman 분석을 이용하여 순화공정을 통해 제작된 wafer의 내부결함밀도 및 결정성을 측정하였다. 분석결과, micropipe 및 planar defect의 밀도는 각각 100개/$\textrm{cm}^2$, 30개/$\textrm{cm}^2$으로 순화처리를 통한 내부결함의 감소로 인해 고품질의 6H-SiC 단결정의 성장이 가능하였다

• 한국식품위생안전성학회지
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• 제26권3호
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• pp.254-259
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• 2011

본 연구에서는 동맥경화의 원인으로 알려진 사람 low density lipoprotein (LDL)에 대한 garlic oil의 산화억제 효과에 대하여 실험하였다. Garlic oil을 HPLC로 분석한 결과 diallyl disulfide, diallyltrisulfide, diallyltetrasulfide and diallyl pentasulfide 등의 유황화합물이 많이 들어 있었다. 사람 LDL을 $Cu^{2+}$ 및 macrophages 유도 oxidized LDL로 산화시킬 때 garlic oil을 20~60${\mu}g$/mL 범위에서 첨가하며 실험하였을 때 용량 의존형으로 억제되었고, garlic oil을 60 ${\mu}g$/mL 첨가하였을 때 LDL의 산화가 거의 억제되었으며, 산화 LDL의 전기영동에 의한 이동거리도 60 ${\mu}g$/mL 농도에서 거의 억제되었다. 그리고 garlic oil은 동맥의 내피세포에서도 용량 의존형으로 억제효과를 나타내었다. 또한 garlic oil은 tocopherol, ascorbic acid 보다 약간 높은 억제효과를 나타내었다. 이상의 결과에 따르면 garlic oil은 macrophage 및 내피세포에서 LDL의 항산화 효과가 있어 LDL의 산화 억제효과가 있는 것으로 나타났다.

• 농촌계획
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• 제12권2호
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• pp.57-64
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• 2006

The experiment was carried out to determine the distribution of total coliform the translocation of heavy metals and the salt accumulation in soils following the supply of ground water, the domestic wastewater and the ultraviolet treatment of domestic wastewater during the spinach and the chinese cabbage cultivation. There were not much changes in the Total-N, Total-P and cations in soils following the ultraviolet treatment of the domestic wastewater. However, the density of total coliform was dramatically reduced from 894MPN/100mL to 5MPN/100mL. The diagnosis of composition of soil after the harvest of chinese cabbages and spinach has shown that the concentration of Na$^+$ was 3-4 times higher in plot using domestic wastewater than in plot using ground water. When domestic wastewater and ground water were used in growing spinach md chinese cabbage at 50% each, the application of chemical fertilizers reduced about 25% to 50% compared to the criteria set down by the Rural Development Administration and there was not significant difference in terms of harvest. Using non-ultraviolet treatment of domestic wastewater directly on spinach and chinese cabbage has resulted in excessive density of total coliform at 25,000MPN/100mL. Even when ultraviolet treatment, the density was still high at 2,000MPN/100mL. The high density of total coliform even following ultraviolet treatment of domestic wastewater is considered to be caused by photo-reactivation of micro-organism. When reusing domestic wastewater, the application of sterilization such as ultraviolet, ultrasonic and electron-beam for public health and hygiene reasons may provide safe supply of agricultural water.

• 한국토양비료학회지
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• 제47권1호
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• pp.28-35
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• 2014

Due to recent interest of the consumers on safe farm products and the government's political support for eco-friendly agriculture, organic fruit production has been growing continuously. This research was conducted in order to study the effect of cover plants on soil microbial community on cover plants and establish an organic fruit cultivation method through choosing optimal cover plant. As a result of investigating soil microbial population density, the bacterial density in soil showed an increasing trend in June compared to April, and there was a decreasing trend in bacterial density of the soil in August compared to June. The density of actinomycetes in soil increased around 1.6 times in June compared to April when the soil was covered with hairy vetch. The increase of filamentous fungus in crimson clover group was 6.1 times higher in June compared to April and in hairy vetch group, the increase was 4.9 times higher in June compared to April. As a result of analyzing DNA extracted from the soil categorized by different types of cover plants using DGGE method, soil collected from April had higher number of bands detected from different locations according to different types of cover plants. Diversity of the bands from the soil collected from August showed higher range of reduction. As a result of analyzing soil microbial community by different period and the types of cover plants using Pyrosequencing method, microbes were detected in the order of Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, and Firmicutes. Distribution rate of Firmicutes increased in the soil collected in August compared to June and this was shown in all types of cover plants by twice the amount.

• 정보처리학회논문지C
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• 제13C권6호
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• pp.741-748
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• 2006

센서 기술의 발전으로 무선 센서 네트워크는 빠르게 발전하고 있으며, 다양한 분야의 적용이 예상되고 있다. 무선 센서 네트워크에서 가장 중요한 요소 중의 하나는 네트워크를 에너지 효율적으로 운용하는 것이다. 이러한 목적을 위해 에너지 효율적인 라우팅 프로토콜에 대한 많은 연구가 진행되고 있다. 본 논문에서는 LEACH-C에서 제안한 클러스터 헤드 선정 알고리즘에 노드들의 밀도를 같이 고려한 향상된 클러스터 헤드 선정 알고리즘을 제안하고 시뮬레이션 하였다. 제안된 알고리즘은 LEACH-C와 실행 속도는 거의 유사하면서 11% 이상의 성능 향상 결과를 제공하였다. 본 논문의 시뮬레이션 결과는 클러스터 헤드 선정 시에 헤드와 다른 노드들 간의 거리 뿐 아니라 밀도를 고려하는 것이 센서네트워크의 에너지 이용에 보다 효율적임을 보여주었다.

• 천문학회보
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• 제35권2호
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• pp.49.1-49.1
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• 2010

The study of pores, small penumbraless sunspots, can give us a chance to understand how strong magnetic fields interact with convective motions in the photosphere. For a better understanding of this interaction, we investigate the temporal variation of several tiny pores smaller than 2". These pores were observed by the Solar Optical Telescope (SOT) onboard Hinode on 2006 December 29. We have analyzed the high resolution spectropolarimetric (SP) data and the G-band filtergrams taken during the observation. Magnetic flux density and Doppler velocities of the pores are estimated by applying the center of gravity (COG) method to the SP data. The horizontal motions in and around the pores are tracked by adopting the Nonlinear Affine Velocity Estimator (NAVE) method to the G-band filter images. As results, we found the followings. (1) Darkness of pores is positively correlated with magnetic flux density. (2) Downflows always exist inside and around the pores. (3) The speed of downflows inside the pores is negatively correlated with their darkness. (4) The pores are surrounded by strong downflows. (5) Brightness changes of the pores are correlated with the divergence of mass flow (correlation coefficient > 0.9). (6) The pores in the growing phase are associated with the converging flow pattern and the pores in the decay phase with the diverging flow pattern. Our results support the idea that a pore grows as magnetic flux density increases due to the convergence of ambient mass flow and it decays with the decrease of the flux density due to the diverging mass flow.

• Journal of Nutrition and Health
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• 제25권7호
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• pp.569-577
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• 1992

To study the effects of the age and the dietary protein content on Ca metabolism male rats of 1 month 6 month 12 month of age were fed experimental diets containing 5%, 15% or 50% casein for 4 weeks. Food and ca intake were higher in old rats and in high protein groups. The weight ash and Ca contents of femur and tibia were higher in old rats. The higher dietary protein level resulted in higher skeletal weigh ash and Ca contents. But high protein diet(50% casein) lead to reduced bone mineral density(ash/dry bone weight) and Ca density(Ca/dry bone weight) in 1 month old rats. Low protein diet(5% casein) on the other hand reduced the bone growth even though the bone density was higher in this group. The ill effect of low protein diet was not evident in 12 month old rats. Glomerular filteration rate(GFR) and urinary Ca excretionincreased with age and with dietary protein level especially in 12 month old rats. Serum immunoreactive parathyroid hormone(iPTH) level tended to be higher in aged rats but was not affected by dietary protein level except 1 month old rats where 50% protein group showed significantly higher value. This study showed that the dietary protein level seemed to have different effect on Ca metabo-lism in rats of different age., The low bone density in the high protein group of growing rats may be due to the higher iPTH level and increased urinary Ca. The dietary protein level however had no effects on the bone composition in aged rats even though the higher urinary Ca excretion. In conclusion this study suggests that high protein intake from young may lead to less peak bone mass and to increase the bone loss in later years, which would increase the risk for osteporosis.