• Journal of Korea Society of Industrial Information Systems
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• v.28 no.1
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• pp.27-34
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• 2023

The optimal assignment problem between agents and tasks is known as one of the representative problems of combinatorial optimization and an NP-hard problem. This paper covers multi agent-multi task assignment problems with uncertain completion probability. The completion probabilities are generally uncertain due to endogenous (agent or task) or exogenous factors in the system. Assignment decisions without considering uncertainty can be ineffective in a real situation that has volatility. To consider uncertain completion probability mathematically, a mathematical formulation with stochastic programming is illustrated. We also present an algorithm by using the sample average approximation method to solve the problem efficiently. The algorithm can obtain an assignment decision and the upper and lower bounds of the assignment problem. Through numerical experiments, we present the optimality gap and the variance of the gap to confirm the performances of the results. This shows the excellence and robustness of the assignment decisions obtained by the algorithm in the problem with uncertainty.

• Women's Health Nursing
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• v.8 no.1
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• pp.116-123
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• 2002

The purpose of this study was to investigate the relationship between knowledge of breast feeding and practice of feeding pattern. A sample of 117 mothers who have the babies between age from 1 month to 12 months were selected from one university hospital and one public heath care center in J city. The data were collected with the questionnaire during the period from the January. 5, 2002 through January. 30, 2002. Analysis was done by using frequency, percentage, t-test, analysis of variance, and scheffe test. The results of this study can be summarized as follows. Comparision of the method of feeding by general characters. Income state, rearing (p=.019), rearing supporters(p=.026), infant age(p=.03) have shown significant difference as the variables affecting Breast practice rate. Breastfeeding rate were 24.8%, mixedfeeding type, 14.5%, milkfeeding type, 60.7%. The mean of knowledge on breastfeeding by feeding patterns were the highest in the group of breastfeeding. There was statistical significance between the group of breast feeding and milkfeeding(p=.000). In the conclusion, this study revealed that knowledge of breastfeeding promoted practice of breastfeeding. Therefore, to promote practice of breastfeeding, it is necessary that nurses provide adequate information about knowledge of breastfeeding.

• Korean Journal of Child Studies
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• v.33 no.2
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• pp.185-201
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• 2012

The purpose of the present study was to investigate the structural relationships between adolescent problem behaviors and related variables. The subjects of this study consisted of 250 to second graders from a middle school in S city in the Gyeongbuk province of South Korea. The sample variance-covariance matrix was analyzed using AMOS 20.0, and a maximum likelihood minimization function. The results were as follows : First, marital conflict in terms of the father's open communication model indicated both a direct and indirect effect upon adolescent problem behaviors. Marital conflict in terms of the father's problematic communication model revealed an indirect effect upon adolescent problem behaviors also indicated that these behaviors were also mediated by the father's problems communication. Second, a open communication style on the part of the father indicated a partially mediating effect on the relationship between marital conflict and adolescent problem behaviors. The problematic communication model on the part of the father revealed a very clear mediating effect on the relationship between marital conflict and adolescent problem behaviors.

• Journal of Korean Physical Therapy Science
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• v.30 no.3
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• pp.41-48
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• 2023

Background: This study examined the effects of the bridge exercise with trunk rotation on the thickness of body trunk muscles, including external oblique, internal oblique, and transverse abdominis in healthy male adults. Design: Randomized controlled trial Methods: Twenty-four men were evenly divided into a trunk rotation bridge exercise group and a basic bridge exercise group by drawing lots. The two groups performed the respective exercise for thirty minutes, three times a week for six weeks. repeated measure analysis of variance (ANOVA) was used after distinguishing between three different time points before the experiment, three weeks after the experiment, and six weeks after the experiment. The significance level was set at 0.05. In case an interaction between time and group existed, the paired t-test was used to examine the within-group difference. The independent-sample t-test was used to check the between-group difference. The significance level was set at 0.05. Results: All the men showed a significant change over time in their external oblique, internal oblique, and transverse abdominis muscles. An interaction between time and group was also found (p<0.05). Conclusion: The bridge exercise with trunk rotation causes a meaningful difference in the thickness of external oblique, internal oblique, and transverse abdominis muscles. Therefore, this study proposes the use of this exercise for lower-back stabilization in future research and clinical settings.

• Journal of Ginseng Research
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• v.35 no.1
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• pp.31-38
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• 2011

In order to distinguish the cultivation area of Panax ginseng, principal component analysis (PCA) using quantitative and qualitative data acquired from HPLC was carried out. A new HPLC method coupled with evaporative light scattering detection (HPLC-ELSD) was developed for the simultaneous quantification of ten major ginsenosides, namely $Rh_1$, $Rg_2$, $Rg_3$, $Rg_1$, Rf, Re, Rd, $Rb_2$, Rc, and $Rb_1$ in the root of P. ginseng C. A. Meyer. Simultaneous separations of these ten ginsenosides were achieved on a carbohydrate analytical column. The mobile phase consisted of acetonitrile-water-isopropanol, and acetonitrile-water-isopropanol using a gradient elution. Distinct differences in qualitative and quantitative characteristics for ginsenosides were found between the ginseng roots produced in two different Korean cultivation areas, Ganghwa and Punggi. The ginsenoside profiles obtained via HPLC analysis were subjected to PCA. PCA score plots using two principal components (PCs) showed good separation for the ginseng roots cultivated in Ganghwa and Punggi. PC1 influenced the separation, capturing 43.6% of the variance, while PC2 affected differentiation, explaining 18.0% of the variance. The highest contribution components were ginsenoside $Rg_3$ for PC1 and ginsenoside Rf for PC2. Particularly, the PCA score plot for the small ginseng roots of six-year old, each of which was light than 147 g fresh weight, showed more distinct discrimination. PC1 influenced the separation between different sample sets, capturing 51.8% of the variance, while PC2 affected differentiation, also explaining 28.0% of the variance. The highest contribution component was ginsenoside Rf for PC1 and ginsenoside $Rg_2$ for PC2. In conclusion, the HPLC-ELSD method using a carbohydrate column allowed for the simultaneous quantification of ten major ginsenosides, and PCA analysis of the ginsenoside peaks shown on the HPLC chromatogram would be a very acceptable strategy for discrimination of the cultivation area of ginseng roots.

• Journal of Korean Public Health Nursing
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• v.15 no.2
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• pp.225-238
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• 2001

The purpose of this study is to examine public health nurses for their morale, test the effect of each factor on the morale, determine the variables affecting the morale, and thereby, provide for some basic data useful to the development of personnel affair administration for nurses. The survey on the nurses for public health centers was conducted for 10 days from April 23 to May 2, 2001; 96 nurses from Pusan, 101 from Kyonggi-do and 108 from Kangwon-do. The results of the study are as follows; 1. For the demographic variables, those aged between 31 and 39 accounted for the majority $(50.2\%)$ of the sample. $90.8\%$ was married, and $67.9\%$ of the sample graduated from junior colleges. $29.6\%$ of them had worked for 10-14 years and $62.5\%$ was of the seventh rank. $62.3\%$ of the nurses was recruited, and $59.4\%$ had chosen the public job for its guaranteed status. Half the nurses were working for the county population of which was more than 260 thousands, and $53\%$ of the nurses was serving the public health centers with 11-15 members. $47.3\%$ of them perceived that their living standard is middle or lower. 2. The degree of the moral was found as mean score. 2.65, which is interpreted as low. It has 11 factors. The rank of mean score of the factors is job satisfaction (3.36), sense of belonging (3.36), sense of recognition (3.30), stress due to supervision (3.13), degree of participation (3.05) and self-achievement (3.04), while those scoring lower points were assurance of status (2.58), pay level (2.53), working conditions (2.35) and promotion opportunity (2.31). 3. The degree of moral depending on the demographic variables was significantly affected by such variables as age. academic background, career, rank, employment method, motive for the job, size of the population served and living standards. 4. The result of the Stepwise multiple regression analysis for the morale factors, it was found that self-achievement accounted for $61\%$ of the total variance of the degree of morale, followed by stable status $(18\%)$, working conditions $(8\%)$, job requirements $(4\%)$ and promotion opportunities $(2\%)$; these five factors explained about $94.6\%$ of total variance of the degree of nurses' morale. On the other hand. age $(8\%)$ and academic background $(2\%)$ accounted for $10\%$ of the total variance of the degree of morale. 5. The factors affecting nurses' job life was economic need $(26.7\%)$, personnel management $(17.5\%)$, sense of recognition $(13.2\%)$, human relationship $(11.0\%)$, stable status and personal development in rank. On the other hand, the factors influencing on their possible resignation were children's bringing-up $(27.8\%)$, poor personnel management and promotion $(13.3\%)$, workload $(11.1\%)$ and little personal development $(8.9\%)$, Since such morale factors as promotion opportunity, working condition. pay level and stable status scored lower, it is required to reconsider those factors to improve nurses' morale.

• Journal of Korean Academy of Nursing
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• v.20 no.3
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• pp.399-413
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• 1990

This descriptive study was under taken to explore relationships among the quality of life, health locus of control and perceived state of health persons with cancer to contribute theoretical understanding about these phenomenon of interest to the quality of nursing care. The subjects of this were 200 persons with cancer (100- in patients and 100- out patients), both male and female, between 30 and 59 years of age. Data were obtained using a convenience sample technique from two university hospitals in seoul from August, 1989, to June, 1990. The instruments used for this study were the Quality of life scale developed by Ro, You - Ja and the Health Locus of Control scale developed by Wallston & Wallston. Data were analyzed using a SAS program for ANOVA, t-test, Schefffe test, Pearson Correlation Coefficients and Stepwise multiple regression. The results were as follows : 1. The scores on the quality of life scale ranged from 95 to 191 with as mean of 147.85(range 47 to 235). The Mean scores(range 1-5) on the different dimensions were family relationships 3.50, relationships with neighbours 3.48, self - esteem 3.17, physical state and function 2.99, economic life 2.93 and emotional life 2.91. 2. Significantly higher scores on the quality of life and demographic characteristics were as follows : the quality of life for women(t＝2.80, p＝ .006), for those without complications(t＝2.54, p＝ .013), and for those who perceived their illness as mild(F＝4.85, p＝ .009). Higher scores on quality of life were correlated with the following : 1) emotional state and the age group 50-59(F＝3.43, p＝ .34). 2) economic life and higher income(F＝6.72, p＝ .002), those without complications(t＝2.68, p＝ .00), and those who perceived their illness as mild(F＝3.11, p＝ .05). 3) self-esteem and marriage(F＝3.64, p＝.028), those without complications(t＝2.18, p＝.03), and those who perceived their illness as mild(F＝7.72, p＝.000). 4) physical state and funciton and the age group 30-39(F＝4.65, p＝.010), those without complications (t＝2.00, p＝.05), and those who perceived their illness as mild(F＝3.38, p＝.04). 5) family relationship and those who live with their spouse(t＝2.82, p＝.005). 3. There was a significant positive correlation between the subjects perceptions of their current state of health and the quality of life score(r＝.4364, p＝.0001). 4. There was no relationship between Locus of control and quality of life in this sample. 5. Stepwise multiple regression analysis showed that: 1) the perception of current health status was the main predictor and accounted for 20.11% of the total variance. 2) sex and educational level accounted for an additional 21.71% of the total variance. 6. The quality of life and the perception of their current health status of these patients with cancer were generally lower than those of healthy adults as noted in previous studies. In conclusion, the quality of life for these cancer patients was generally low especially in regard to their emotional state. The current perceived state of health, sex, complications and perceived degree of illness were important variables relatiog to quality of life.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.374-380
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• 2007

Chemical and sensory profiles of 5 Korean commercial rice wines (yakju) were developed using descriptive, physicochemical, and volatile analyses. Color, 6 aroma, and 5 taste attributes of these rice wines were evaluated by a panel of 13 judges. Sample wines were analyzed for titratable acidity, ethanol content, pH, Hunter colorimeter value, organic acids, and free sugars. Volatile analysis of the samples revealed the presence of 2 acids, 7 alcohols, 19 esters, and 5 miscellaneous compounds. Based on principal component analysis of the descriptive data, rice wines were primarily separated along the first principal component, which accounted for 57% of the total variance between the rice wines with high intensities of 'color' and 'sweet aroma' versus 'ginseng' aroma.

• Journal of the Korean Statistical Society
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• v.21 no.2
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• pp.93-110
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• 1992

A model selection approach is used to find out whether the mean and the variance of a unique sample are different from the pre-specified values. Normal distribution is selected as an approximating model. Kullback-Leibler discrepancy comes out as a natural measure of discrepancy between the operating model and the approximating model. Several estimates of selection criterion are computed including AIC, TIC, and a coupleof bootstrap estimator of the selection criterion are considered according to the way of resampling. It is shown that a closed form expression is available for the parametric bootstrap estimated cirterion. A Monte Carlo study is provided to give a formal comparison when the operating family itself is normally distributed.

• Communications for Statistical Applications and Methods
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• v.13 no.3
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• pp.669-683
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• 2006

Model-based methods are generally used for small area estimation. Recently Shin and Lee (2003) suggested a method which used spatial correlations between areas for data set including some auxiliary variables. However in case of absence of auxiliary variables, Direct estimator is used. Even though direct estimator is unbiased, the large variance of the estimator restricts the use for small area estimation. In this paper, we suggest new estimators which take into account spatial correlation when auxiliary variables are not available. We compared Direct estimator and the newly suggested estimators using MSE, MAE and MB.