• 한국해양공학회지
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• 제14권3호
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• pp.78-83
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• 2000

In this study, CT specimens were prepared from AST SA516 Gr. 70 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at 25$^{\circ}C $, -60$^{\circ}C $, -80$^{\circ}C $ and -100$^{\circ}C $ and in the range of stress ratio of 0.05, 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ${\delta} K_{th}$ in the early stage of fatigue crack growth (Region I) and stress intensity factor range $\delta $K in the stable of fatigue crack growth (Region II) were increased in proportion to descending temperature. It was assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN -$\delta $K in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It was assumed that the fatigue crack growth rate da/dN is rapid in proportion to descending temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.

• Journal of Advanced Marine Engineering and Technology
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• 제10권1호
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• pp.65-73
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• 1986

Surface fatigue crack propagation tests by plane bending fatigue were conducted on the welding specimens of an aluminium alloy, A5083-0, having an edge through thickness notch to study the fatigue crack growth characteristics. Moreover, the experiments were performed in order to clarify the fatigue crack initiation and growth. The properties of fatigue crack growth were quantitatively inspected in welded metal, heat-affected zone and base metal of the welding specimens. The main results obtained are summarized as follows: 1. It is found that the hardness distributions of A5083-0 aluminium alloy weldments are quite different with those of steel material weldments, so that the hardness distribution becomes lower in the following order: base metal, heat-affected zone and weld metal. 2. It is observed that the grain size of this specimen weldment appears to be almost equal to the base metal, when TIC welding method is adopted. 3. In a surface fatigue crack initiation and growth, the fatigue crack does not begin by opening-closing mechanism until hardening is saturated at the crack tip. 4. The fatigue crack growth characteristics of A5083-0 alluminium alloy weldments can be concluded.$${\frac{da}{dn}}=C({\Delta}K)^n=3.8{\times}10^{-9}{({\frac}{1}{2}{\Delta}S_t{\sqrt{{\pi}a}})}^{2.4}$$

• 임상간호연구
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• 제29권1호
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• pp.85-94
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• 2023

Purpose: The purpose of this study was to investigate the influencing factors of post-traumatic growth in patients with gastrointestinal cancer. Methods: A cross-sectional study was conducted, enrolling 120 patients with gastrointestinal cancer. Their general characteristics, disease-related characteristics, perceived illness intrusiveness, levels of optimism, social support, and post-traumatic growth were assessed through self-administered questionnaires. The collected data were analyzed using descriptive statistics, independent t-test, oneway ANOVA, Pearson's correlation, and multiple regression analysis. Results: The mean score of post-traumatic growth was 52.74 points(total score of 92 points). Among the subscales of post-traumatic growth, levels of the preciousness of life were the highest, and relating with others was the lowest. The post-traumatic growth was found to be significantly correlated with optimism (r=.48, p<.001), social support (r=.47, p<.001), and depression (r=-.37 p<.001). Factors associated with post-traumatic growth were optimism (β=.36, p<.001), social support (β=.31, p<.001), and depression (β=-.27, p<.001). Conclusion: Given that prevalence of gastrointestinal cancer is increasing in Korea, identifying general, psychological, and social factors affecting post-traumatic growth among this population will be helpful in clinical practice. Integrated strategies to increase optimism and social support and lower depression should be considered to improve the post-traumatic growth of patients with gastrointestinal cancer.

• Journal of Biosystems Engineering
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• 제34권3호
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• pp.161-166
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• 2009

This study was conducted to investigate the growth characteristics of cherry tomatoes in greenhouse using far infrared heating system. The far infrared greenhouse heating systems were installed in two ways on the greenhouse side wall and at the greenhouse ceiling. The heating characteristics of far infrared heating system were analyzed by investigating the heating load, internal temperature, energy consumption, growth characteristics and quality evaluation. The results were compared with heated air heating system using kerosene. The results showed that tomatoes grown in the greenhouse with the far infrared heating system had relatively better plant height, leaf length, leaf width, stem diameter than ones from the greenhouse with hot air heating system and both heating methods had no significant difference on Cherry tomato sugar contents. At the same time, the far infrared heating system reduced heating cost from 34.5 to 41.4% on comparing with hot air heating system.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.796-802
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• 2009

The effects of docking on growth traits, fattening performance, carcass characteristics and blood biochemical parameters were investigated using 24 fat-tailed Sanjabi single-born male lambs raised from a large commercial sheep herd. The lambs were randomly divided into two groups. One group (n = 12) were docked at two days of age with rubber-rings using an elastrator. The second group (n = 12) were left intact. After weaning (90 days), all lambs were moved to rustic rangelands for 40 days. Then all the lambs were fed concentrates ad libitum for 60 days during the fattening period. Growth traits, body weight and average daily gain (kg) were recorded at the end of the weaning and fattening periods. Blood biochemical parameters including urea, total protein, glucose, triglycerides, cholesterol, low-density lipoproteins (LDL) and high-density lipoproteins (HDL) were measured during the fattening period. Finally, at the end of the fattening period, eight lambs (4 intact and 4 docked lambs) were slaughtered in order to determine carcass characteristics. Fat-tail docking had no effect (p>0.05) on lamb growth from birth to weaning. Body weight and average daily gain of docked lambs were significantly higher (p<0.05) than for intact lambs at the end of the fattening period. There was no difference in carcass measurements between the two groups, except for chest depth and leg weight which were higher (p<0.05) in docked lambs. During the fattening period, cholesterol and LDL of docked lambs were less than in intact lambs (p<0.05). The current results indicated that docking with rubber rings causes an improvement in growth traits during the fattening period and leads to desirable carcass characteristics compared to intact lambs; interestingly, this procedure had a significant effect on the lowering of blood cholesterol and LDL of docked lambs.

• 한국자원식물학회지
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• 제33권6호
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• pp.651-658
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• 2020

The aim of this study was to investigate the comparative growth characteristics and ginenoside contents of wild-simulated ginseng on different years (7 and 13-year-old) by monitoring soil properties of cultivation regions. Plant and soil samples were collected from 6 different cultivation regions. Soil organic matter (OM), total nitrogen (TN) and cation exchangeable capacity (CEC) were significantly higher in 13-year-old wild-simulated ginseng cultivation regions compared to 7-year-old wild-simulated ginseng cultivation regions. Growth characteristics of wild-simulated ginseng had shown significantly higher in 13-year-old wild-simulated ginseng compared to 7-year-old wild-simulated ginseng. Ginsenoside G-Rb1, Rb2, Rc, Rd, Re, Rf, Rg1 were significantly higher in 13-year-old wild-simulated ginseng than 7-year-old wild-simulated ginseng. According to the results of correlation analysis, soil OM, TN and CEC of the cultivated regions were positively correlated with the growth of wild-simulated ginseng. In addition, the root length of wild-simulated ginseng showed positive correlation with ginsenoside content. Hence, this study was able to investigate the correlation between growth and ginsenoside content of wild-simulated ginseng based on soil characteristics of the cultivation regions.

• 대한기계학회논문집
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• 제17권9호
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• pp.2145-2152
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• 1993

The objective of this paper is to examine the detection limit, growth characteristics and notch curvature radius in short crack problem. Measurement techniques such as ultrasonic method and back-face strain compliance method were adopted. The fatigue crack growth rate of the short crack is slower than that of a long crack for a notched specimen. The characteristic of crack growth and crack closure is same as the case of a delay of crack growth caused by constant amplitude load for an ideal crack or single peak overload for a fatigue crack. The short crack is detected effectively by ultrasonic method. A short surface crack occurs in the middle of specimen thickness and is transient to a through crack depth is larger than the notch curvature radius.

• 대한기계학회논문집A
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• 제25권5호
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• pp.797-804
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• 2001

To obtain representative fatigue crack growth characteristic curve in residual stress field, fatigue crack growth test was carried out at various stress ratio and fatigue crack growth characteristic curve was represented using crack closure concept. Obtained results are as follows;K(sub)op/K(sub)max was independent of K(sub)max when R was lower than 0.5 and crack closure phenomenon was not observed when R is higher than 0.5. therefore neglecting crack closure behaviour, actual fatigue crack growth rate can be underestimated. Thus, considering crack closure phenomenon, fatigue crack growth characteristics curve of A 106 Gr B Steel weldment can be effectively estimated.

• Journal of Welding and Joining
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• 제16권4호
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• pp.47-54
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• 1998

Various equipments in plants are welded with two different materials and it is required to investigate the effects of fatigue crack propagation on the neighborhood of a welded portion. The characteristics of fatigue crack growth in the base metal of carbon and stainless steel, in the carbon and stainless steel sides located in the neighborhood of welded portion (carbon/stainless steel), respectively and welded portion, are investigated. The results show that the crack growth in the welded portion (carbon/stainless steel) is an average value of the crack growths in the carbon and stainless steel respectively located in the neighborhood of the welded portion. It is found that the crack growth in the welded portion is not significantly different from those in the carbon and stainless steel sides. Hence it can be concluded that the structure welded with two different materials wold not impede the integrity based on the fatigue crack growth.

• 복식문화연구
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• 제15권1호
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• pp.37-57
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• 2007

The purpose of this study was to analyze the body measurements of boys and girls at puberty and to provide the fundamental data for pubescent apparel manufacturers to produce clothing that reflect their physical characteristics. A total of 549 boys and 529 girls aged between 10 and 14 were measured in the capital area from March 4 to April 3, 2004. Data were collected from 35 anthropometric items and 12 photographic items per a person. SPSS Ver. 12 program was used in data analysis including means, standard deviation, t-test and Duncan test. The main results of this study were as follows. They showed the significant difference of their growth in accordance with the increase of their ages. There were also the difference between boys and girls. As for height and length items, boys showed a slow growth at the age of $10{\sim}11\;and\;12{\sim}13$. Those at the age of $11{\sim}12\;and\;13{\sim}14$ showed rapid growth. That is, an active growth was followed by a slow growth and that phenomenon repeatedly occurred. On the other hand, girls showed remarkable growth at the age $10{\sim}11$ and the growth rate gradually slowed down afterward. Regarding circumference items, boys at the age of $11{\sim}12\;and\;13{\sim}14$ showed remarkable growth. This results showed that boys at the age of $11{\sim}12$ had vertical growth and horizontal growth at the same time and for those at the age of $13{\sim}14$, growth was more conspicuous in horizontal direction. Meanwhile, for girls, the growth rate was high at the age of $11{\sim}12$, somewhat later than the age of the growth of height and length. As for breadth-related items and depth-related items, for both sexes two items grew steadily throughout the ages, breadth-related items showed a higher growth rate than that of depth-related items. This study analyzed the body measurements of pubescent boys and girls and the results showed that, for boys, an active physical growth took place at the age of 13 according to previous studies, but the findings of this study suggested that the phenomenon now occurred at the age of $11{\sim}12$, which proved that physical growth took place earlier than before. Also, an active growth was followed by a slow growth. Girls at puberty showed remarkable growth of height at the age of $10{\sim}11$ that is consistent with previous studies and then showed horizontal growth at the age of around 12, having a voluminous body shape.