• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.167-177
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• 2010

Recent competitive and technological changes during the past decade have accelerated the need for better capital recovery methods. Competition and technology have together shortened the expected lives of property which could not have been forecasted several years ago. Since the usage of technological growth models has been prevalent in various technological forecasting environments, the various forms of growth models have become numerous. Of six such models studied, some models do significantly better than others, especially at low penetration levels in predicting future levels of growth. A set of criteria for choosing an appropriate model for technological growth models was developed. Two major characteristics of an S-shaped curve were elected which differentiate the various models; they are the skewness of the curve and underlying assumptions regarding the variance of error structure of the model.

• Structural Engineering and Mechanics
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• v.69 no.4
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• pp.361-369
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• 2019

The determination of Paris' law parameters based on crack growth experiments is an important procedure of fatigue life assessment. However, it is a challenging task because it involves various sources of uncertainty. This paper proposes a novel probabilistic method, termed the S-N Paris law (SNPL) method, to quantify the uncertainties underlying the Paris' law parameters, by finding the best estimates of their statistical parameters from the S-N curve data using a Bayesian approach. Through a series of steps, the SNPL method determines the statistical parameters (e.g., mean and standard deviation) of the Paris' law parameters that will maximize the likelihood of observing the given S-N data. Because the SNPL method is based on a Bayesian approach, the prior statistical parameters can be updated when additional S-N test data are available. Thus, information on the Paris' law parameters can be obtained with greater reliability. The proposed method is tested by applying it to S-N curves of 40H steel and 20G steel, and the corresponding analysis results are in good agreement with the experimental observations.

• Nuclear Engineering and Technology
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• v.38 no.3
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• pp.277-284
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• 2006

In order to ensure the structural integrity of nuclear welded structures during design life, the fatigue life has to be evaluated by fatigue analysis procedures presented in technical codes such as ASME B&PV Code Section III. However, existing fatigue analysis procedures do not explicitly consider the presence of welded joints. A new fatigue analysis procedure based on a structural stress/fracture mechanics approach has been recently developed in order to reduce conservatism by erasing uncertainty in the analysis procedure. A recent review of fatigue crack growth data under various mean loading conditions using the structural stress/fracture mechanics approach, does not consider the mean loading effect, revealed some significant discrepancies in fatigue crack growth curves according to the mean loading conditions. In this paper, we propose the use of the stress intensity factor range ${\Delta}K$ characterized with loading ratio R effects in terms of the structural stress. We demonstrate the effectiveness in characterizing fatigue crack growth and S-N behavior using the well-known data. It was identified that the S-N data under high mean loading could be consolidated in a master S-N curve for welded joints.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.519-522
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• 2002

Body weight-age data from 60 bulls and 60 steer of Hanwoo in the Korean Native Cattle Improvement Center was used to determine the growth curve parameters with Gompertz equation. Estimated growth curve functions were as follows; Bul l : $W_t$ = 906.1.exp{－3.956.exp(－0.0034t)} Steer : $W_t$ = 823.1.exp{－3.301.exp(－0.0027t} Mature weight estimated with Gompertz equation of bull is higher than earlier studies. And the major factor raising differences from the other is feeding level. Relative body weights of steer to bull were rapidly decreased to 79.2% until 19.5 months of age, and then increased slowly. The ratio was 90.8% at mature state. Body weight was under-estimated for bull at birth, but over-estimated for steer, and the body weight variations of bull were larger than the steer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.96-98
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• 2013

Through reviewing the characteristics of digital TVs, which have emerged in CES since 2005, in the view of technology growth and substitution curves, this paper is to provide a prediction on the next generation's multi-media on smart environment. As a result, digital TV has been developed on the flow of its technology growth curve from the early version in 2005 to smart digital TV in 2013, which emphasizes the key word "connected", and it has already come to the market puberty. Also, as it has the characteristics such as supporting multi functional and multi media environments and introducing curved or flexible display, the digital TV in CES 2013 has reached in introductory stage on the technology substitution curve.

• Journal of Haehwa Medicine
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• v.7 no.2
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• pp.609-620
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• 1999

Over the period between January 1997 and December 1998, herbal medicine was more than three times administered to the patients coming to Na dong gyu's Oriental Medical Clinic on account of the symptom of growth deficiency. According to radiological opinions about the patients providing cooperation for measuring their height and weight as well as their bone age every three months, it was found that the growth plates were not closed. A research was conducted for 200 children randomly selected of patients in prepuberty (they grew by less than 5cm a year before treatment at a age of 12years for female children and 14years for male children). As a result, the following conclusion was drawn: 1. The randomly selected subjects were made up of 116 male and 84 female children in terms of gender. The age direstribution was most 10 to 12 years in 86 children(34.00%), followed by 8-10 years(27.50%) and 12 to 14 years(19.50%). 2. Considering the distribution of sick children's parental height, the fathers of 141 children(70.50%) measured less than 170cm high, the subaverage height, while the mothers of 172 children(86%) measured less than 160cm high, the subaverage height. It was shown that sick childen's height was genetically influenced by their parents. 3. Children patients's weight at a time of birth was most 3.1-3.5kg for 85 children(44%) and less than 2.5kg which came under the range of growth dificiency for 19 children(9.5%). 4. The highest proportian of the children patients with growth dificiency(56.33%) had the symptom of digestive disorders, of which 77 children patients(18.78%) had anorexia, 16.59% of children patients had the high level of respiratory disorders. Both the digestive disorder and the respiratory disorder put together, they had the high rate of 72.92%. Therefore, this indicates that both the digestive disorder and the respiratory disorder have a great effect on children's growth dificiency. 10.74% of chilren patients were shown to have allergic disorders, which indicates that they also exert an effect on growth deficiency. Specifically, 7.07% of the children patients had the high level of obesity, which shows that an excessive uptake of nutrition may rather induce children to have growth dificiency though an appropriate amount of nutritional uptake is necessary. 5. Comparing their bone age and their chronological age, 58 children patients(29.00%) showed that they were the same at the highest percent. 79 children patients(39.50%) showed that thier bone age was lower than their chronological age. And 63 children patients(31.50%) showed that their bone age was higher than their chronological age. 6. As regards the prescription administered to children patients for treating their growth dificiency, Growth tang A related to the kidney, the congenital factor, of the causes for growth dificiency in traditional Oriental Medicine was administered to 108 children patients(54%), whereas the Growth tang B related to the spleen, the acquired factor, was administered to 92 children patients(46%). 7. 116 male children patients with growth dificiency had the average value of growth for one year before treatment, 4.39cm, while 84 female children patients had the average value of growth for one year before treatment, 4.24cm. A total of 200 children had the average value of growth for one year before treatment, 4.33cm. The annual average value of growth in growth curve surveyed by the Korea Pediatrics Society was 5.79cm. Compared to this value, the one year average value of growth for 108 male and female children patients taking Growth tang A was shown be 8.44cm, which indicates a greater growth by 4.12cm(95.37%) in comparison with the average value of growth before treatment, 4.32cm, and a greater growth by 2.65cm(45.77%) compared to 5.79cm, the average value of growth in growth curve surveyed by the Korea Pediatrics Society. Also, the average value of growth before treatment for 92 male and female children patients taking Growth tang B was shown to be 8.47cm, which indicates a greater increase by 4.15cm(96.06%) compared to 4.32cm, the average value of growth before treatment and a greater increase by 2.67cm(46.29%) in comparison with 5.79cm, the average value of growth in growth curve surveyed by the Korea Pediatrics Society. Considering the average value of growth for male and female children patients taking Growth tang A and B, it was shown to be 8.46cm, which indicates a greater increase by 4.14cm(95.81%) compared to 4.32cm, the average value of growth before treatment, and a greater increase by 2.67cm(46.11%) compared to 5.79cm, the average value of growth in growth curve surveyed by the Korea Pediatrics Society.

• The Journal of Pediatrics of Korean Medicine
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• v.12 no.1
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• pp.145-162
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• 1998

The purpose of this study was to determine the effects of oriental medical care on growth deficiency children. These cases were collected to investigate the effects of oriental medical care on growth deficiency children. So the cases were divided into 5 groups. The growth velocity was compared to a normal growth curve, and the results are as follows: 1. Oriental medical care was efficient when the epiphysial plates were not closed. 2. In female middle school beyond 1st grade students and in male middle school 3rd grade students who had almost closed epiphysial plates, the oriental medical care was not efficient and did not promote growth velocity. endothelium were used for the experiment using organ bath. 3. In the cases where the parent were very short, the effects of the oriental medical care to promote growth velocity was not efficient. 4. when we treated children of normal height, their growth velocity was over the normal growth curve. 5. In preschool aged children, oriental medical care was very efficient to promote children's growth. 6. The principle oriental medical care was to make balanced their body and digestive organs by using herb medicines that have the capability to promote the growth of the bones, and build strong muscles.

• Journal of Ocean Engineering and Technology
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• v.3 no.2
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• pp.617-617
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• 1989

This paper deals with a fatigue life prediction of a surface crack based on the experimentally obtained relationship between surface crack length ratio $a/a_{f}$ and cycle ratio $N/N_{f}$ using micro computer. Firstly $a/a_{f}$-$N/N_{f}$ curves obtained from experimental tests, were assumed as three curves UC(the upper limit curve), LC(the lower limit curve) and MC(the middle curve), and these were utilized to predict the fatigue life. Comparing the calculated values which represent the characteristics of crack growth behaviors from the three assumed curves with the experimental ones, it has been found that in the stable crack growth region, they coincide reasonably well each other. And the differences between the fatigue lives obtained from the assumed curves and the experimental fatigue life did not exceed 20%. Using the characteristics of $a/a_{f}$-$N/N_{f}$ curves, it is possible to predict the da/dN-Kmax curves and the S-$N_{f}$ curves.

• Journal of Ocean Engineering and Technology
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• v.3 no.2
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• pp.108-117
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• 1989

This paper deals with a fatigue life prediction of a surface crack based on the experimentally obtained relationship between surface crack length ratio $a/a_{f}$ and cycle ratio $N/N_{f}$ using micro computer. Firstly $a/a_{f}$-$N/N_{f}$ curves obtained from experimental tests, were assumed as three curves UC(the upper limit curve), LC(the lower limit curve) and MC(the middle curve), and these were utilized to predict the fatigue life. Comparing the calculated values which represent the characteristics of crack growth behaviors from the three assumed curves with the experimental ones, it has been found that in the stable crack growth region, they coincide reasonably well each other. And the differences between the fatigue lives obtained from the assumed curves and the experimental fatigue life did not exceed 20%. Using the characteristics of $a/a_{f}$-$N/N_{f}$ curves, it is possible to predict the da/dN-Kmax curves and the S-$N_{f}$ curves.

• Quantitative Bio-Science
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• v.37 no.2
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• pp.125-132
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• 2018

In this study, noble strains of lactic acid bacteria were isolated and identified by genetic analysis of 16s rRNA. Also, pH-dependent growth curve, cholesterol assimilation ability and sugar production efficiency were measured. Lactic acid bacteria were identified to inhabit in the milks from various animals. Results of sequence analysis showed that there were differences in 16S rRNA sequence among strains and part of gene deletion was also recognized. Growth rates were varied, too, depending on the pH of the medium. Lactobacillus rhamnosus LOCK908 isolated from cow milk showed the highest growth rate and high cholesterol assimilation ability. Results of sugar fermentation tests were relatively consistent with the sequencing results. So, we propose newly isolated Lactobacillus rhamnosus LOCK908 as useful candidate for a starter of fermented beverage and probiotics. Results of this study will contribute to the isolation and identification of noble Lactic acid bacteria and to the public health.