• 제목/요약/키워드: $C_{f(mean)}$

검색결과 483건 처리시간 0.052초

철도 차량 정비 작업자를 위한 일회용 부직포 작업복의 온열적 성능 평가 (Evaluation of the Thermal Properties of Disposable Coveralls for Railroad Carriage Maintenance Workers)

  • 최정화;이주영;김소영
    • 한국의류학회지
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    • 제28권8호
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    • pp.1175-1185
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    • 2004
  • This study evaluated thermo-physiological and subjective properties of improved disposable coveralls for railroad carriage maintenance through climatic chamber trials and a filed study. Subjects wore five kinds of disposable coveralls (Type A: a disposable coverall on the market, Type B: a coverall with an improved hood and size-adjustable design, Type C: a coverall with a portable hood, Type D: a coverall with small holes for ventilation, Type E: a sleeveless coverall, Type F: a separated type of coverall with half sleeves) The air temperature in the climatic chamber was set in 9$^{\circ}C$ and 30$^{\circ}C$ For each condition, subjects simulated the railroad work for 120min. and rectal temperature, skin temperatures, clothing microclimate and subjective sensations were measured. The results of chamber trials showed rectal temperature and clothing microclimate did not display significant differences by clothing type. In 30$^{\circ}C$ air temperature, mean skin temperature was higher in Type E and Type F than in Type A(p<0.05) but between the improved coveralls(B-F), we could not find any significant difference. In the case of thermal comfort, the most preferred types were Type B and Type C in 9$^{\circ}C$ and Type F in 30$^{\circ}C$. All subjects felt more comfortable in the improved coveralls than in coveralls of the market (Type A). In field study, workers preferred Type B, Type C and Type F to Type A but the most favorite type differed by the specific type of work. Especially, workers were dissatisfied that Type D tore easily due to lots of small holes around the armpits and Type I did not protect workers' shoulder and arms from oil contamination. According to the climatic chamber trials and field study, the most effective coveralls were Type B and Type C for winter and Type F for summer.

Application of probabilistic method to determination of aerodynamic force coefficients on tall buildings

  • Yong Chul Kim;Shuyang Cao
    • Wind and Structures
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    • 제36권4호
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    • pp.249-261
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    • 2023
  • Aerodynamic force coefficients are generally prescribed by an ensemble average of ten and/or twenty 10-minute samples. However, this makes it difficult to identify the exact probability distribution and exceedance probability of the prescribed values. In this study, 12,600 10-minute samples on three tall buildings were measured, and the probability distributions were first identified and the aerodynamic force coefficients corresponding to the specific non-exceedance probabilities (cumulative probabilities) of wind load were then evaluated. It was found that the probability distributions of the mean and fluctuating aerodynamic force coefficients followed a normal distribution. The ratios of aerodynamic force coefficients corresponding to the specific non-exceedance probabilities (Cf,Non) to the ensemble average of 12,600 samples (Cf,Ens), which was defined as an adjusting factor (Cf,Non/Cf,Ens), were less than 2%. The effect of coefficient of variation of wind speed on the adjusting factor is larger than that of the annual non-exceedance probability of wind load. The non-exceedance probabilities of the aerodynamic force coefficient is between PC,nonex = 50% and 60% regardless of force components and aspect ratios. The adjusting factors from the Gumbel distribution were larger than those from the normal distribution.

Nicotine Dihydroiodide의 結晶構造 (The Crystal Structure of Nicotine Dihydroiodide)

  • 구정회;김훈섭
    • 대한화학회지
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    • 제9권3호
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    • pp.134-141
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    • 1965
  • 니코틴 二沃化水素酸鹽의 結晶은 直角非等軸結晶係(料方晶係)에 屬하며 空間群은 $p2_12_12_1$이다. 單位格子의 크기는 a=7.61, b=11.01 및 e=17.27${\AA}$이며 單位格子안에 들어있는 化學單位의 水는 4이다. 이 結晶의 構造를 X-線廻折法에 依하여 解析하였으며 R 値 ${\sum}{\mid}{\mid}F_{\circ}{\mid}-{\mid}F_c{\mid}{\mid}{\div}{\sum}{\mid}F_{\circ}{\mid}$$F_{orl}$$_{kol}$에 關하여 各各 0.16및 0.14의 값을 이룰 때까지 精密化 하였다. 原子間距離의 精密化를 試圖하지는 않았지만 피리딘 고리 안의 C-C 및 C-N의平均距離는 各各 1.40 및 $1.35{\AA}$의 값을 가진다. 피리딘 고리 內의 各原子는 實驗誤差內에서 同一平面上에 있으며 피롤리딘 고리에서는 $C_6,\;C_7,\;C_8$$N_2$原子는 大略 同一平面上에 있으나 $C_9$는 이 平面으로 부터 約0.22${\AA}$ 떨어져있다. 피리딘 고리의 平面과 $C_6,\;C_7,\;C_8$$N_2$가 이루는 平面의 各法線은 約 $94^{\circ}$를 이루고 있다. 이코틴 二沃化水素酸鹽의 한 分子內의 두個의 요오드 原子中 한개는 피리딘 고리의 窒素原子와 $3.55{\AA}$의 距離로 連結되여 있으며 다른 한개는 피콜리딘 고리의 窒素原子 와 $3.58{\AA}$의 距離로 連結되여 있다. 結晶內에서 各 分子는 Van der Waals force로 서로 接燭되여 있다.

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Use of the Yeast 1.5-Hybrid System to Detect DNA-Protein-Protein Interaction

  • Kim, Sook-Kyung;Han, Jin-Hee
    • Journal of Microbiology
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    • 제38권2호
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    • pp.113-116
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    • 2000
  • Escherichia coli F plasmid partition apparatus is composed of two trans-acting proteins (SopA and SopB) and one cis-acting DNA sequence (sopC). The SopB-sopC complex has been suggested to serve a centromere-like function through its interaction with chromosomally encoded proteins which remain to be identified. In this paper, we are introducing a new yeast 1.5-hybrid system which assembles the two-hybrid and one-hybrid system as a mean to find and additional component of the F plasmid partition system, interacting with DNA (sopC)-bound SopB protein. The results indicates that this system is a promising one, capable of selecting an interacting component.

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충돌형 F-O-O-F 인젝터의 이중분무 중첩영역에서의 분무특성에 관한 연구 (Spray Characteristics in the cross region of twin spray between impinging F-O-O-F type injectors)

  • 권기철;이은상;강신재;노병준
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.758-763
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    • 2001
  • This paper presents twin spray characteristics of two impinging F-O-O-F type injectors in which fuel and oxidizer impinge on each other to atomize under the various conditions. The droplet size and velocity in the impinging spray flow field were measured using a PDPA. The droplet size and velocity were investigated at mixture ratios of 1.5, 2.0, 2.47 and 3.0 for four injectors in which two single F-O-O-F injectors were arranged at intervals of 20.8, 31.2, 41.6 and 62.4mm respectively. In general, the arithmetic mean diameter, SMD and standard deviation of droplet size in the interaction area (X=0 and Y=0mm) were smaller. The axial velocity in the interaction area was slightly higher. Considering the behavior of impinged droplets using the We number calculated by using the axial velocity instead of the relative velocity in line C in Fig. 1(b) for four injectors, it is consumed that the We number over 500 had the possibility to disintegrate, and the We number below 500 had it to cohere after impingement of twin spray. The results of this study can be used for the design of a nozzle for liquid propellant rockets.

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한국산 적포도주의 관능적 특성에 관한 연구 (III) (A Study on the Sensory Characteristics of Korean Red Wine)

  • 이장은;홍희도;최희돈;신용섭;원유동;김성수;고경희
    • 한국식품과학회지
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    • 제35권5호
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    • pp.841-848
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    • 2003
  • 국내산 포도품종을 이용하여 G(거봉100%), M(머루100%), C(캠벨100%), GM(거봉70%+캠벨30%), GC(거봉70%+캠벨30%) 포도주를 제조하여 프랑스산 적포도주 (Cabernet Sauvignon, 1998)와 함께 색도, 향기성분, 맛, 종합평가에 관한 선호도를 순위법(ranking test)으로 측정하고, 분석적 관능평가 방법으로 평가하였다. C(캠벨)는 4.76으로 색도면에서 가장 높은 선호도를 보였으며, 다음으로는 GM(거봉+머루)이 3.94, F(프랑스)가 4.67, M(머루)이 3.70, GC(거봉+캠벨)가 2.65, G(거봉)가 1.47로 높은 선호도 순서를 보였다(p<0.001). 향기성분의 평가에서는 M이 3.94, C가 3.76, GM이 4.12, F가 3.76으로 이들은 유의적으로 가장 높은 선호도를 보였으며, 3.12를 얻은 GC와, 2.29를 얻은 C는 이들보다 낮은 선호도를 보였다(p<0.01). 맛의 평가에서는 4.75를 얻은 F와, 4.25를 얻은 C에 이어, GM이 3.37, GC가 3.50, G가 2.75, M이 2.37로 높은 선호도 순서를 보였다(p<0.001). 색도, 향기성분, 맛을 바탕으로 한 전체적인 종합 평가에서는 F가 4.81, C가 4.06, GM이 3.87로 각각 높은 선호도를 보였으며 다음으로는 3.64를 얻은 GC, 2.37을 얻은 G, 2.44를 얻은 M의 순이었다(p<0.001). 전체적인 종합평가에 가장 높은 영향을 준 인자는 맛 항목으로 69.2%를 설명할 수 있었다. 다음은 색도와 향기성분 순이었으며, 이들 세 항목으로 포도주의전체적 종합평가를 74.4% 설명할 수 있었다. 회귀분석 결과 purple과 red color는 색의 선호도를 각각 28.9%, 8.5% 설명할 수 있었으며, grape flavor는 향기성분에 관한 선호도를 14.4% 설명할 수 있었고 sweet, acid, bitter, salty taste들은 맛의 선호도를 17.3% 설명할 수 있었다. 상관관계 결과 purple과 red 항목은 각각 grape taste, floral taste와 그리고 grape, oak, flavor들과도 양의 상관관계를 보였고, grape flavor는 floral flavor, grape taste, floral taste들과 양의 상관관계를 나타냈으며(p<0.001), $SO_2$향과는 음의 상관관계를 보였다(p<0.001). Sweet taste는 grape, floral flavor와 양의 상관 관계를 보였으며(p<0.001), bitter, astringency taste와는 음의 상관관계를 나타내어(p<0.01), sweet taste가 강할수록 바람직한 향기성분과 맛의 강도가 강하게 평가되었으며, 또한 이들 항목의 점수가 높을수록 선호도도 높이 평가되어 sweet taste, grape, floral flavor와 bitter, astringency taste의 조화는 적포도주의 관능적인 면에서 중요한 요소들임을 알 수 있었다.

Genetic Mapping of Resistant Genes in Brassica pekinensis Against Plasmodiophora brassicae Race 6

  • Lee, Gung-Pyo;Baek, Nam-Kwon;Park, Kuen-Woo
    • The Plant Pathology Journal
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    • 제18권5호
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    • pp.266-270
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    • 2002
  • Inbred lines of Chinese cabbage KU-101 (resistant line against Plasmodiophora brassicae race race 6) and CS-113 (susceptible line) were crossed and their progeny lines F$_1$, BC$_1$F$_1$, F$_2$, and F$_3$ were produced for the construction of the genetic linkage map of R brassicae race 6-resistant Brassica campestris ssp. pekinensis genome. Restriction fragment length polymorphism (RFLP) was applied to compare between parents and their f$_2$ progenies with a total of 192 probes and 5 restriction enzymes. The constructed RFLP map covered 1,104 cM with a mean distance between genetic marker of 8.0 cM, and produced 10 linkage groups having 121 genetic loci. The loci of P. brassicae race 6 (CR6)-resistant Brassica genome were determined by interval mapping of quan-titative trait loci (QTL), which resulted from bioassay using the same race of the fungi in P3 population. Resistant loci were estimated in numbers 1 (Gl) and 3 (G3) linkage groups. In the regression test, Gl had a value of4.8 logarithm of odd (LOD) score, while C3 had values of 4.2-7.2. Given these results, the location of the CR6-resistant loci within the Brassica genome map can now be addressed.

Correlations of Genic Heterozygosity and Variances with Heterosis in a Pig Population Revealed by Microsatellite DNA Marker

  • Zhang, J.H.;Xiong, Y.Z.;Deng, C.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권5호
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    • pp.620-625
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    • 2005
  • Correlation of microsatellite heterozygosity with performance or heterosis was reported in wild animal populations and domestic animal populations, but the correlation with heterosis in a crossbreeding F$_1$ pig population remained uncertain. To explore this, we had random selected and mated Yorkshire${\times}$Meishan (F, n = 82) and their reciprocal (G, n = 47) to F$_1$, and used the two straightbreds as control groups (Yorkshire = 34, Meishan = 55), and observed the heterosis of birth weight (BWT), average daily gain (ADG) and feed and meat ratio (FMR). Two Kinds of measurement-individual heterozygosity (IH) and individual mean d$^2$ (lg value, ID) were used as index of heterozygosity and variance from 39 microsatellite marker loci to perform univariate regression analysis against heterosis. We detected significant correlation of IH with BWT in all of F$_1$ (F+G) and in F. We observed significant correlation of ID with ADG in all of F$_1$ (F+G), and with FMR in all of F$_1$ (F+G) and in F. There was significant maternal effect on heterosis, which was indicated by significant difference of means and distribution of heterosis between F and G. This difference was consistent with distributions of IH and ID, and with difference of means in F and G. From this study, it would be suggested that the two kinds of genetic index could be used to explore the genetic basis of heterosis in crossbreeding populations but could not determine which is better.

한국 남해안 조간대에 서식하는 우럭, Mya japonica의 자원생태학적 특성 (Population Ecological Characteristics of the Soft-shelled Clam, Mya japonica in the Intertidal Zone of South Sea in Korea)

  • 이선길;장창익
    • 수산해양기술연구
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    • 제36권3호
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    • pp.234-243
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    • 2000
  • This paper is to study population ecological characteristics, including growth parameters, survival rate, instantaneous coefficients of natural and fishing mortalities, and age at first capture of the soft-shelled clam, Mya japonioa in the intertidal zone of South Sea in Korea. For describing growth of the clam a von Bertalanffy growth model was adopted, The von Bertalanffy growth curve had an additive error structure and the growth parameters estimated from a non-linear regression were SH/sub ∞/=79.83mm, K=0.26, and t/sub 0/= -0.01. Survival rate (S) of the soft-shelled clam was 0.26 (SD=0.02). The instantaneous coefficients of natural mortality (M) was estimated to be 0.78/year and fishing mortality (F) 0.57/year for the soft-shelled clam. The age at first capture (t/sub c/) was estimated as 2.69 year. The mean densities of the soft-shelled clam by bottom type were 3.40 inds./m²(SE=0.18) in the sand, 63.4 inds./m²(SE= 0.53) in the muddy sand, and 0 inds./m2 (SE=0) in the gravelly sand. The mean densities of the soft-shelled clam by 3 different areas were 4.88 inds./m²(SE=0.09), 2.61 inds./m²(SE=0.13), 7.20 inds./m²(SE=0.18), respectively and the biomass of the clam were estimated as 131mt, 121mt, 665mt, respectively. An yield-per-recruit analysis showed that the current yield-per-recruit of about 8.30g with F=0.57/year and the age at first capture (t/sub c/) 2.69 year, was lower than the maximum possible yield-per-recruit of 9.60g. Fixing to at the current level and increased fishing intensity (F) could produce an increase in the predicted yield-per-recruit from 8.30g to about 9.40. However, estimated yield-per-recruit increased to 1.30g by decreasing to from the current age (2.69 year) to age two with F fixed at the current level. Yield-per-recruit was estimated under harvest strategies based on F/sub max/ and F/sub 0.1/.

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어류의 행동에 관한 연구 - 1 . 붕어의 유영력 - (Study on the Behavior of the Fish - 1 . The Swimming Force of Crusian Carp , Carassius Carassius -)

  • 손태준
    • 수산해양기술연구
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    • 제20권1호
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    • pp.1-5
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    • 1984
  • 고기가 자망에 이망될 숙건하에 그물면에 작용하는 붕어(Carassius carassius)의 유영력을 시험수조에서 strain gauge를 써서 즉정한 결과는 다음과 같다. 1. 순간최대유영력 및 지속최대유영력과의 체중과의 관계는 F 하(M) =1.45W, F 하(s) =0.29W 이다. 2. 순관최대유영력 및 지속최대유영력과의 체중과의 관계는 F 하(M) =0.11L 상(2.63), F 하(S) =0.15L 상(1.77)이다. 3. 붕어의 유체저항계수는 C 하(s) ≒0.287이다.

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