• Journal of the Korean Statistical Society
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• v.33 no.2
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• pp.191-202
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• 2004

The paper considers nonparametric empirical Bayes estimation of residual survival function at age t using a Dirichlet process prior V(a). Empirical Bayes estimators are proposed for the case where both the function ${\alpha}$(0, $\chi$] and the size a(R$\^$+/) are unknown. It is shown that the proposed empirical Bayes estimators are asymptotically optimal at a rate n$\^$-1/, where n is the number of past data available for the present estimation problem. Therefore, the result of Lahiri and Park (1988) in which a(R$\^$+/) is assumed to be known and a rate n$\^$-1/ is achieved, is extended to a(R$\^$+/) unknown case.

• Korean Journal of Poultry Science
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• v.29 no.4
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• pp.255-258
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• 2002

A study was conducted to investigate the correlation of cecal anaerobic bacterial counts with the cecal length in growing chicks. Half of 160 chicks of five weeks old were housed in cages and the remainings were kept with goats in free-range and allowed to have free access to goat's feed and faeces. All the experimental birds were fed ad libitum on a commercial chick formula diet during the period of 5 to 12 weeks of age. Body weight was larger in birds reared in the cage than in those reared on the field at 8 weeks of age (P<0.05), but vice versa at the end of experiment (P<0.05). The cecal length was longer in field-rearing than in cage-rearing at 6, 9, 10 and 11 weeks of age (P<0.05). The cecal length was correlated with body weight gain in both rearing groups (r=0.816 f3r cage-rearing, r=0.816 for field-rearing). The cecal anaerobic bacterial counts were significantly higher in field- rearing than in cage-rearing at 6, 9, 10 and 11 weeks of age (P<0.05). The cecal length was highly correlated with cecal anaerobic bacterial counts in cage- (r=0.9549) and field-(r=0.9866) rearing. It is concluded that the correlation of increase cecal length with increased cecal anaerobic bacterial counts ted a libelous of goat's faeces in growing chicks.

• Korean Journal of Animal Reproduction
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• v.8 no.1
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• pp.46-55
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• 1984

The purpose of the experiment was to clarify morphologically normal growth pattern of the ductus deference in accordance with the sex maturity of meat-type cockerels. 1. Diameter of lumens in u, pp.r, mid and lower parts of ductus deferens, the most conspicuous enlargement of lumen was observed in the lower part. Heights of epithelial layers of ductus deferens showed abrupt growth at 12 weeks of age with subsequent gradual growth in all the part of u, pp.r, mid and lower, and heights of those at 30 weeks were a, pp.oximately 4 times as large in the u, pp.r and mid parts and 5 times as large in the lower part in contrast to those at 4 weeks of age. Thickness of muscular layer of ductus showed gradual growth in contrast with the diameter of lumen and height of epithelial layer, showing 1.3 times as large in the u, pp.r part, 1.6 times in the mid part and 1.9 times in the lower part at 30 weeks of age in contrast to the thickness at 4 weeks of age. 2. Within 10 weeks after hatching, lining cells of ductus deferens were mainly composed of round cells and columnar cells in simple columnar epithelium. During 10th to 20th week, the lining cells were mainly composed of high columnar cells and round cells in pseudostratified epithelium. From 22nd week, the lining cells were composed of pseudostratified columnar cells. Whereas round cells disa, pp.ared gradually. Enlargement of lumen and pooling of sperms in ductus deferens coincided with the maturation of seminiferous tubules. 3. In simple correlation between the values of testis weight and the values from various measurements in the ductus deferens, there was significant correlation coefficient with each other. 4. In the India ink absorption test, India ink granules were not absorbed on the epithelium of the ductus deferens, but the granules reactive to acid phosphatase a, pp.ared in a line on the free border of each parts of the ductus deferens. The granules reactive to alkaline phosphatase were noted on the luminal border of ductus deferens mainly, but weak reaction showed than acid phophatase were a, pp.ared. The granules reactive to PAS were a, pp.ared mostly near on the free border of hte epithelial cells of ductus deferens. 5. Number of sperm, Indes of sperm vitality and MRT in the different parts of ductus deferens were tended to be somewhat dominant in the mid and lower parts than in u, pp.r part, even though not significant in the statistical analysis. Ratio of sperm abnormality was tended to be relatively high in the u, pp.r part too, and in the sperm of abnormality blunted head was less in number significantly in the mid and lower part than in the u, pp.r part.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1103-1109
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• 2002

This study investigated the effect of 2-bromo-$\alpha$-ergocryptine (anti prolactin agent) on plasma levels of prolactin, oestradiol-17$\beta$ and progesterone in domestic hen during the active period of lay. Fifty healthy female White Leghorn birds were administered with anti prolactin agent (2-bromo-$\alpha$-ergocryptine, Sigma-USA., methane sulphonate salt, $C_{32}H_{40}BrN_5O_5.CH_4SO_3$) subcutaneously @100$\mu$g/kg body weight at weekly intervals from 17th to 36th week of age. Another group of fifty birds as controls were given placebo in place of bromocriptine. The level of prolactin remained lower in treated birds than in the control birds from 19 to 36 weeks of age. Level of prolactin even in the control group was found to decrease during the peak production period. Oestradiol-$17{\beta}$ and progesterone concentration in treated birds were significantly (p<0.01) higher than the controls during the treatment. Egg production, is positively correlated with oestradiol-$17{\beta}$ (r=0.02; r=0.67) and progesterone (r=0.49; r=0.90) in control and treated groups respectively where as prolactin level is positively correlated with egg production in the control birds (r=0.07). Prolactin levels were negatively correlated with egg production (r=-0.55) in treated birds; and oestradiol-$17{\beta}$ (r =-0.71; r=-0.53) and progesterone (r=-0.22; r=-0.27) respectively in control and treated groups. The total number of pause days during the treatment period decreased significantly (p<0.01) in the treated group compared to the control group. The reduction in pause days in treated group resulted in 1.76% increase in egg production over that in control group. The increase in egg laying days and the total egg production were found to be significant (p<0.01). These results indicate that a lower level of prolactin in circulatory blood enhances egg production in the domestic hen.

• International journal of advanced smart convergence
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• v.9 no.2
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• pp.28-37
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• 2020

We conducted a comprehensive review on the previous research on r-Learning. By reviewing 843 previous studies about r-Learning published from 2004 to 2015, this study investigated 1) the trend of research on r-Learning over time, 2) the characteristics of targeted students in r-Learning, 3) the educational activities implemented for r-Learning, and 4) the types of educational robots used for r-Learning. The study found that the research on r-Learning has rapidly and steadily increased and the types of educational activities and educational robots has been diversified. Relying on the findings of this review, this study suggests 1) ensuring growth in both the quality and the quantity of research on r-Learning, 2) broadening the target student population of r-Learning beyond the age-limited boundaries, 3) enhancing educational activities of r-Learning, and 4) recognizing the necessity for systematic and clear concepts of types of educational robots.

• Journal of Oral Medicine and Pain
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• v.26 no.4
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• pp.377-393
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• 2001

In order to study the closure stage of cranial sutures and its correlations with age, the ectocranial closure stage of coronal suture, sagittal suture, and lambdoidal suture of 67 skulls was measured. Among the skulls kept at the department of anatomy, college of medicine, Yonsei University, the ones with ages identified were used for this study. These measurements of suture closure were conducted by 4 examiners independently. The sutures were further divided by Frederic's method into 16 suture parts. The closure stages were classified by five stages of Broca-Ribbe. The following results were obtained: 1. The inter-observer reliability among 4 examiners showed high intraclass correlation coefficient of over 0.75(mean : 0.856) in all suture parts. Therefore, the determination of closure stage wasn't influenced by the subjective view of each examiner. 2. In all suture parts, the closure stage increased proportionally with age.(p<0.01) In terms of each suture part, the S2 part of sagittal suture showed the highest correlation(68.1%) while the L1-R part of lambdoidal suture showed the lowest correlation(51.3%). In addition, in terms of suture types, the correlation with age decreased in the order of sagittal suture(60.0%), coronal suture(57.7%), and lambdoidal suture (55.7%). In general, the average value of suture closure stages had 57.8% correlation with age(p<0.01). 3. The most frequent suture closure stage according to age group was '0' for ages below 30, '0' and '1' for ages within the 30's, '1' and '2' for ages within the 40's, and '2' for ages within the 50's. With older age groups, the frequency of '3' and '4' increased, and the suture closure stage increased proportionally with age. 4. The mean age by closure stage of each suture were within the 40's for the closure stage of '1', within the 50's for the closure stage of '2', and from 50's through 60's for the closure stage of '3'. The standard deviation was over 10 for all closure stages. In addition, at the same suture closure stage, the mean age according to the coronal suture was higher than the ages according to the sagittal suture or lambdoidal suture. Especially, C1-R, C1-L, C2-R, and C2-L parts showed the highest age when at the same suture closure stage. 5. The values appropriate for age estimations using suture closure stages of 16 suture parts were calculated, and a calculator for age estimation ($R^2=0.6944$, p<0.01) by ectocranial suture closure stage for Koreans is presented. From the above results, the method of using the closure stage of sutures of the skull to estimate age can be useful in individual identification of forensic science. Further extensive and accurate research using larger samples would be worthy of study.

• Journal of Korea Technology Innovation Society
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• v.2 no.3
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• pp.1-18
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• 1999

The purpose of this research is to analyze the influence of the factors on the performance of na-tional R&D support program. A LISREL model was employed to analyze the relationship between the factors and the performance which was measured in the technological and commercial aspect. The result of the study reveals the R&D management business administration the age and the size of the company industry domain are the factors whose relationship with the performance are sta-tistically significant.

• Journal of Animal Science and Technology
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• v.44 no.2
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• pp.171-180
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• 2002

Data were collected from 1996 through 2000 on Korean Native Goats by the National Livestock Research Institute of Korea were used to estimate genetic parameters for birth, 3 month, and 6 month body weights. Estimates were obtained with MTDFREML. Model included animal and maternal genetic and residual effects. The model included sex, birth year-season, and feeding type as fixed factors. Average body weights and standard deviation were 1.78${\pm}$0.32 at birth of age, 7.99${\pm}$2.66 at 3 month of age, and 12.08${\pm}$3.20 kg at 6 month of age, respectively. Average body measurements were 36.46cm for withers height, 38.06cm for body length, and 45.56cm for heart girth at 3 month of age, and were 40.27cm for withers height, 42.01cm for body length, and 51.07cm for heart girth at 6 month of age, respectively. Estimates of heritability were 0.66 for birth weight, 0.34 for 3 month body weight, and 0.27 for 6 month body weight, respectively. Maternal effects would be important for birth and 3 month body weights and may not be needed in a model for 6 month body weight.

• Journal of Korean Academy of Nursing
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• v.14 no.1
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• pp.69-82
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• 1984

The general fearfulness of hospitalized school-age children and the emotional anxiety of their mothers were investigated and compared to those of normal children and their mothers, in order to provide theoretical basis for establishing comprehensive nursing care of hospitalized children including their mothers. The present study was carried out from Sept. 5th to Oct. 3rd, 1983. A total of 81 hospital I zed children and their mothers were investigated and 95 normal elementary school children and their mothers as control group were surveyed The general fearfulness of children and the emotional anniety of their mothers were measured through questionaire by using Geer's FSS-Ⅱscale and Spielberger's STAI scale, respectively. The results were analyzed by computer using S.P.S.S. program and summarized as follows: 1. The emotional anxiety of the mothers of hospitalized children was greater than that of normal children's mothers. (P=0.000). 2. The general fearfulness of hospitalized children was greater than that of normal children (p=0.000) 3. The general fearfulness of hospitalized children varied with children's age and sex, mother's age and mother's experience of hospitalization. a) The general fearfulness of the hospitalized children at the age of 7∼9 was greater than that of the age 10∼12. (P=0.020) b) Girl's scored greater fearfulness than boys. (p=0.037) c) The younger mother's age resulted in the higher children fearfulness. (P= 0.0059). d) When the mothers did not have experience of hospitalization, the children's fearfulness was high. (P=0.014) 4. The anxiety-state of hospitalized children's mother was proportionally reacted to their anxiety-trait. (r=0.694, p=0.000) 5. The relationship between mother's emotional anxiety and their hospitalized children's general fearfulness failed to show statistical significance. (r= 0.1184, P＞0.05). These results indicated that the general fearfulness of hospitalized children was affected by environmental factors beside mother's emotional anxiety. An extensive study on the factors influencing the general fearfulness of hospitalized children is needed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.4
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• pp.257-264
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• 2005

We studied age and growth of the sea urchin, Pseudocentrotus depressus, to obtain some informations regarding its sustainable production and appropriate resources reinforcement. The samples were collected at two locations (Ongpo and Bubhwan) in Jeju, Korea. Annual rings were formed from October to January, and this period was well matched with the time just prior to or during their reproduction. Two population regression lines generated by using Walford's plotting with mean radius of each age group showed significant differences in their growth rate between the two sampling locations (p<0.0l). When the regression equations were calculated using either madreporite's radius (R) and test diameter (L) or body weight (W) and test diameter (L), the results were L=23.830+ 11.735R and $W=0.0004L^3$, and no statistically significant differences were detected between the two populations (p>0.2). Based on the data of madreporite's radius and test diameters, two estimated growth equations were $L_t(mm)=72.988(1-e^{-0.412(t-0.596)}\;and\;L_t(mm)=70.195(1-e{-0.365(t-0.51l)}$ in Ongpo and Bubhwan population, respectively. Three distinct annulus groups were recognizable within the distribution of the radii of the annual rings measured from age I to age 5. The mean radii calculated from the same annulus group were all identical even though they were from different age groups.