• Nuclear Engineering and Technology
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• 제50권1호
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• pp.182-189
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• 2018

A neutron generation system was developed to induce fissile fission in a lead slowing down spectrometer (LSDS) system. The source neutron is one of the key factors for LSDS system work. The LSDS was developed to quantify the isotopic contents of fissile materials in spent nuclear fuel and recycled fuel. The source neutron is produced at a multilayered target by the (e,${\gamma}$)(${\gamma}$,n) reaction and slowed down at the lead medium. Activation analysis of the target materials is necessary to estimate the lifetime, durability, and safety of the target system. The CINDER90 code was used for the activation analysis, and it can involve three-dimensional geometry, position dependent neutron flux, and multigroup cross-section libraries. Several sensitivity calculations for a metal target with different geometries, materials, and coolants were done to achieve a high neutron generation rate and a low activation characteristic. Based on the results of the activation analysis, tantalum was chosen as a target material due to its better activation characteristics, and helium gas was suggested as a coolant. In addition, activation in a lead medium was performed. After a distance of 55 cm from the lead surface to the neutron incidence, the neutron intensity dramatically decreased; this result indicates very low activation.

• 한국의류산업학회지
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• 제14권3호
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• pp.423-429
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• 2012

This study investigated purchasing practice and size satisfaction to offer basic data to establish a marketing strategy and produce down-aging clothes for females in their 40s-50s. For the data analysis, crosstabs, factor analysis, and one-way ANOVA were used. The results were as follows; first, middle-aged women were observed to purchase down-aging clothes "to look younger" and not purchase clothes "due to the lack of right sizes." For women who answered to 'not purchase clothes', they also acknowledged that they intended to purchase down-aging clothes in the future if the right size is available. Second, people in their early 40s significantly considered perceptual qualities such as fashion and brand names while people in their late 50s placed the most importance in practicality and wearability. For body shapes, people with overweight body types were found to significantly consider physical performance, practicality, and wearability. Third, the examination of purchase satisfaction levels by age groups showed that younger age groups had high satisfaction level for wear functionality related items that included size and activity however, the late 50s group had the lowest satisfaction level. Middle-aged women purchased clothes to look younger however, they simultaneously wear clothes that are plain and conservative or respectable and graceful. Therefore, the development of products reflect the analysis of designs that can help create a more youthful appearance and women's preferred styles are needed in addition to the establishment of a differentiated sizing system for middle-aged female consumers in the incorporation of the characteristics of middle-aged women's body parts.

• 지질공학
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• 제29권3호
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• pp.201-209
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• 2019

국내 사면 및 터널에서 주로 적용되고 있는 다단 압력을 이용한 그라우팅 방법들은 천공 후 지중에서 지표 방향으로 스텝주입을 하는 상향식 다단압력 그라우팅 방법이며 다수의 연구결과와 축척된 시공실적을 토대로 현재 여러 현장에서 적용되고 있다. 국내에서 하향식 다단압력 그라우팅 방법의 연구결과는 미미한 실정이다. 본 논문에서는 토조시험과 현장시험을 통해 기존 상향식 다단압력 그라우팅 방법과 지표부에서부터 주입을 실시하는 하향식 다단압력 그라우팅 방법의 주입효과를 비교 분석하였다. 토조 시험 결과 하향식 다단압력 그라우팅 방법의 경우 상향식 다단압력 그라우팅 방법에 비해 구근체의 부피는 약 24% 증가하는 것으로 나타났다. 현장시험 결과 하향식 다단 압력 그라우팅 방법이 상향식 다단 압력 그라우팅 방법에 비해 주입 범위가 넓고 면적당 주입 밀집도가 높은 것으로 확인되었다.

• 한국작물학회지
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• 제35권1호
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• pp.34-43
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• 1990

미질에 관련된 주요 형질들의 지역변이정도를 비교하기 위하여 우리나라에서 재배되고 있는 6품종이 벼를 '87-'88년의 2년간에 걸쳐 품종별로 8-20개 지역에서 수집하여 이들 각각의 도정률, 쌀의 외관, 아밀로스함량 및 알칼리 붕괴도, 관능검사에 의한 식미평가, 레오메타를 이용한 밥알의 조직감 그리고 아밀로그라프에 의한 쌀가루의 호화 및 점도특성을 조사하였다. 1. 조사한 미질관련형질 중 정현비율, 현백비율, 백미천립중 및 쌀의 아밀로스합량은 지역변이가 작았으나 완전백미비율, 쌀의 알칼리붕괴도, 쌀가루의 gel consistency, 심복백미비율, 심복백정도와 수명도의 지역변이는 상대적으로 컸으며 특히 심복백미비율의 변이정도는 공시한 6품종에서 모두 컸다. 2. 품종별로 '87년과 '88년 계속해서 심복백미비율이 상대적으로 낮은 쌀을 생산한 지역은 추청벼의 경우 충주, 음성, 안성 및 영덕이었고 동진벼는 안성, 상풍벼는 상주(화서)와 안성, 삼강벼는 춘천, 연천 및 상주(화서), 그리고 용문벼는 상주(화서)와 연천이었다. 3. 관능검사법으로 조사한 식미형질들은 품종, 연도 및 조사항목에 따라서 지역변이정도가 다양하게 변하였으나 레오메타로 조사한 밥알의 조직감 중 식미지수 및 점착성의 지역변이는 매우 컸고 응집성 및 탄력성은 낮은 변이계수를 보였다. 4. 품종별로 식미지수가 2년 연속 평균치보다 높았던 쌀을 생산한 지역은 추청벼는 해당지역이 없고, 동진벼는 안성, 상풍벼는 이천과 영덕, 삼강벼는 여주, 그리고 용문벼는 안성이었고, 점성/경도 비율이 높았던 곳은 추청벼가 김포, 동진벼는 안성, 삼강벼는 이천과 이리, 그리고 용문벼는 춘천이었다. 5. 쌀가루의 아밀로그람특성 중에서는 set back, break down 및 최고점도의 지역변이가 컸다. Set back이 특별히 낮고 break down이 평균치보다 훨씬 높은 쌀을 생산한 지역을 보면 추청벼는 서산과 안성, 동진벼는 안성, 서산 및 화순, 삼강벼는 안성, 서산, 화순 및 계화도 그리고 용문벼는 안성과 충주였다.

• 한국식품조리과학회지
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• 제16권2호
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• pp.151-159
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• 2000

The effects of bromelain and $\alpha$-chymotrypsin treatments on the functional properties(foaming capacity, foaming stability, emulsifying capacity, and emulsifying stability) of soy protein isolate(SPI) and the addition of various sweeteners(sucrose, sorbitol, xylitol) on the quality attributes(viscosity, overrun ratio, melt-down property, and sensory characteristic) of soy ice cream were studied. SPI was more effectively hydrolyzed with $\alpha$-chymotrypsin than bromelain, resulting in a better foaming and emulsifying capacity. Adding xylitol could significantly improve the viscosity, overrun and melt-down property of soy ice creams while the effect was the lowest in the sucrose addition. Bromelain treatment caused a lower apparent viscosity of SPI suspension compared with $\alpha$-chymotrypsin treatment and untreated. The overrun ratios of the soy ice cream prepared with bromelain and $\alpha$-chymotrypsin treated SPI were 18.9∼25.9% and 24.9∼40.3%, respectively as a result of freezing with agitation for 20 min in an ice cream maker. Comparatively, untreated SPI could bring only 15.8∼21.4% overrun ratios after operating for 15 min. The bromelain treatment caused high melt-down tendency of the product while soy ice cream with untreated SPI showed an opposite trend. In sensory characteristics, no significant differences in the strength of beany flavor were noted among the samples. Sweetness, bitter taste, icy feel, and mouthfeel of the product were greatly affected by the enzyme-treatment of SPI. Soy ice cream added with xylitol after $\alpha$-chymotrypsin treatment was the most acceptable among all samples.

• 한국환경과학회지
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• 제22권3호
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• pp.309-318
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• 2013

This study was conducted for determining the influence of artificial structures on benthic macroinvertebrate communities in stream. Sampling was taken at upper(pool), down(riffle) and control(riffle) from two check dams, two weirs, one agricultural reservoir, and one multipurpose dam in northern part of Gyeongsangbuk-do. The benthic macroinvertebrate communities of these structures were surveyed during 2009 to 2011. The simple habitat of benthic macroinvertebrates occurred at the upper sites due to pooling effects from artificial structures. Specifically, Check dam1, Jusanji, Imha dam showed very low biological attribute values compared to the down and control sites, which have greater difference in substrate characteristics. However, in the upper sites of Check dam2, Weir1 and Weir2, the difference of values of biological attributes was relatively smaller. Also, proportion of functional feeding groups and functional habit groups were relatively simpler at upper stream and the degree of community differences was greater between upper and down, control sites. Spearman's correlation between biological attributes and substrate characteristics, water quality parameters had significant correlations; particularly, the substrate characteristics were more significantly related. In conclusion, the pool caused by artificial structures had negative effects on benthic macroinvertebrate communities thus leading to simplified stream habitats at upper stream ecosystems.

• 조명전기설비학회논문지
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• 제22권12호
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• pp.29-35
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• 2008

본 논문에서는 부하전류의 급격한 변화에도 안정적인 출력진압을 얻기 위하여 강압쵸퍼의 전압제어 기를 개선하는 방법으로 부하전류 전향보상기를 제시하였다. 제시된 부하전류 전향보상기의 특성을 확인하기 위해 메이슨(Mason)의 이득공식을 이용하여 기존의 전압제어기가 포함된 전체 시스템의 전달함수와 부하전류 전향보상기가 추가된 전체 시스템의 전달함수를 각각 근궤적선도와 보드선도 상에서 비교하였다. 그 결과 시스템의 극점이 개선되고, 공진주파수에서의 첨두값의 크기 및 절점주파수의 위상여유가 양호한 것을 확인하였다. 따라서, 제시된 제어기법이 강압쵸퍼의 정상상태 및 동특성을 향상시키고 출력에 나타나는 외란에 의한 영향을 감소시킨 것을 확인할 수 있었다.

• 한국작물학회지
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• 제39권1호
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• pp.98-102
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• 1994

율무전분의 호화특성을 조사하여 품질개량 육종의 기초자료를 제공하고자 국내보존 및 일본도입 36품종을 공시재료로 하여 전분, 아밀로스 함량 및 호응집성(Gel consistency)과 아밀로그램 특성을 분석하여 얻어진 결과를 요약하면 다음과 같다. 1. 공시된 율무품종의 전분함량차이는 50.9~78%로서 평균 60.5%를 함유하였다. 2. 율무전분의 아밀로스 함량은 0~7.2%의 범위였고 gel의 길이는 평균 94mm로써 전형적인 찰전분의 특성을 나타내었다. 3. 호응집성이 강산종, 추전종, 중리재래 등은 medium에 가깝고 대부분 품종이 soft에 속하였다. 4. 공시율무의 amylograph의 호화온도, 최고점도, 최저점도 및 break down은 각각 69.0~75$^{\circ}C$, 210~520 BU, 205~425 B 및 5~135 BU의 범위로 품종간 차이가 있었다. 5. 품종간 차이가 현저했던 아밀로그램 특성은 break down type이었고 일반적으로 율무 품종은 set back이 낮았다.

• Earthquakes and Structures
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• 제12권5호
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• pp.529-541
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• 2017

According to the definition, progressive collapse could occur due to the initial partial failure of the structural members which by spreading to the adjacent members, could result in partial or overall collapse of the structure. Up to now, most researchers have investigated the progressive collapse due to explosion, fire or impact loads. But new research has shown that the seismic load could also be a factor for initiation of the progressive collapse. In this research, the progressive collapse capacity for the 5 and 15-story steel special moment resisting frames using push-down nonlinear static analysis, and nonlinear dynamic analysis under the gravity loads specified in the GSA Guidelines, were studied. After identifying the critical members, in order to investigate the seismic progressive collapse, the 5-story steel special moment resisting frame was analyzed by the nonlinear time history analysis under the effect of earthquakes with different characteristics. In order to account for the initial damage, one of the critical columns was weakened at the initiation of the earthquake or its Peak Ground Acceleration (PGA). The results of progressive collapse analyses showed that the potential of progressive collapse is considerably dependent upon location of the removed column and the number of stories, also the results of seismic progressive collapse showed that the dynamic response of column removal under the seismic load is completely dependent on earthquake characteristics like Arias intensity, PGA and earthquake frequency contents.

• 복식문화연구
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• 제13권2호
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• pp.255-268
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• 2005

The purpose of this study was to identify the physical characteristics of early adolescent girls by age. A total of 529 girls aged between 10 and 14 were measured and data were collected from 42 anthropometric and 41 photographic measurements per a person. SAS 8.1 was used in data analysis including means, standard deviations, t-test, Duncan test and frequency analysis. The results of this study are as follows. Most items related to height and length increased significantly at the age of $10\sim11$ and the growth slowed down at the age of $13\sim14$. As for items related to circumference, the growth rate was high at the age of $11\sim12$, and gradually slowed down afterward. Out of circumference items, hip circumference showed the highest growth rate. As for items related to thickness and width, thickness-related items grew quickly at the age of $10\sim12$, and among which bust thickness showed the highest growth rate. As for drop, the difference between hip circumference and waist circumference was most remarkable, but the difference between hip circumference and bust circumference was not large. The largest number of subjects had their menarche during the age of $11\sim12$ and, after menarche, their horizontal growth became active.