• Journal of the Korean Statistical Society
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• v.36 no.1
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• pp.129-148
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• 2007

Frailty estimates from the proportional hazards frailty model often lead us to conjecture the heterogeneity in frailty such that the variance of the frailty varies over different covariate groups (e.g. male group versus female group). For such systematic heterogeneity in frailty, we consider a regression model for the variance components in the proportional hazards frailty model, denoted by the MLFM. However, in many cases, the observed data do not show any statistically significant preference between the homogeneous frailty model and the heterogeneous frailty model. In this paper, we propose a Bayesian model averaging procedure with the reversible jump Markov chain Monte Carlo which selects the appropriate model automatically. The resulting regression coefficient estimate ignores the model uncertainty from the frailty distribution in view of Bayesian model averaging (Hoeting et al., 1999). Finally, the proposed model and the estimation procedure are illustrated through the analysis of the kidney infection data in McGilchrist and Aisbett (1991) and a simulation study is implemented.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.17-28
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• 2017

The modified power method has been studied by many researchers to calculate the higher eigenmodes and accelerate the convergence of the fundamental mode. Its application to multidimensional problems may be unstable due to degenerated or near-degenerated eigenmodes. Complex eigenmode solutions are occasionally encountered in such cases, and the shapes of the corresponding eigenvectors may change during the simulation. These issues must be addressed for the successful implementation of the modified power method. Complex components are examined and an approximation method to eliminate the usage of the complex numbers is provided. A technique to fix the eigenvector shapes is also provided. The performance of the methods for dealing with those aforementioned problems is demonstrated with two dimensional one group and three dimensional one group homogeneous diffusion problems.

• Journal of Korean Elementary Science Education
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• v.29 no.3
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• pp.364-377
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• 2010

The purpose of this study was to analyze the within-group verbal interaction according to leader's personality in Thinking Science activities. For this study, 2 homogeneous small groups by cognitive level selected from one class of sixth grader. Each group was comprised of four students. Leaders of two groups selected from the results of NEO personality assessment and teacher's observation. One who got high scores in extraversion and agreeableness is named a sociable leader, the other who got low scores in extraversion and agreeableness is named a taciturn leader. Verbal interactions during small group activities were audio/video taped and students' interactions were classified into on-task and off-task. On-task included cognitive aspect and affective aspect. Interactions of cognitive aspect were divided into low and high level, also interactions of affective aspect were divided into positive and negative interaction. The results of this study showed that the verbal interactions in the sociable leader group were more activated than those in the taciturn leader group. Also, interaction level of the sociable leader group in cognitive aspect was higher than those of the taciturn leader group. In affective aspect, interaction pattern of the sociable leader group was similar to those of the taciturn leader group. The characteristics of leader's interaction are as follow. The rates of cognitive aspect in the sociable and the taciturn leaders' interactions were much higher than those of affective aspect. This tendency was especially remarkable in the taciturn leader's interactions. However, interaction level of the sociable leader in cognitive aspect was higher than those of the taciturn leader. In affective aspect, positive interaction rate of the sociable leader and the taciturn leader were higher than negative interaction rate.

• Journal of The Korean Society of Clinical Toxicology
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• v.5 no.1
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• pp.8-14
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• 2007

Purpose: Organophosphorus insecticides tend to be regarded as a homogeneous single entity. We aimed to determine whether organophosphate poisoning differs by subgroups in clinical features and severity. Methods: We retrospectively reviewed medical records of all patients with acute organophophorus poisoning from January 1998 to December 2006. We investigated clinical features, Glasgow coma scale (GCS), laboratory findings, QTc intervals, management, and outcomes. Results: A total of 109 patients were included. The dimethoxy group experienced significantly longer times than the diethoxy group for ventilation duration (0.6 day vs. 0.2 day, p=0.006), ICU duration (2.0 day vs. 0.8 day, p=0.037), and total admission duration (2.8 day vs. 0.9 day, p=0.008), except in cases of dichlorvos poisoning. Also, the GCS of the dimethoxy group (except with dichlorvos) was significantly lower than for the diethoxy group (dimethoxy, $11.2{\pm}5.2$ vs. diethoxy, $13.8{\pm}2.4$, p= 0.021). QTc intervals for the dimethoxy group (except with dichlorvos) tended to be somewhat greater than for the diethoxy group (dimethoxy, $452.9{\pm}16.1\;msec$ vs. diethoxy, $429.6{\pm}40.9\;msec$). There were 65 patients with dichlorvos ingestion, and 2 of these patients (3%) died. Conclusion: When compared to the diethoxy group, the dimethoxy group of organophosphates (with the exception of dichlorvos) were associated with poorer prognostic value for indicators such as GCS, QTc interval, requirement for intubation, ICU duration, and total admission duration. Within the dimethoxy group, patients with dichlorvos poisoning had relatively better prognoses than for the other dimethoxy group organophosphates studied.

• Korean journal of food and cookery science
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• v.6 no.4 s.13
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• pp.59-68
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• 1990

Juices prepared from carrots, apples, and mandarin oranges were fermented with Leuconostoc mesenteroides or along with Saccharomyces cerevisiae. The pH of the fermented juices was not found significantly different between the mixed and single-cultured groups. The juices containing 0.5% NaCl had lower pH than the groups without 0.5% NaCl. The final pH of the single-cultured gruops was the highest among the sample groups. However, reducing sugar content of the mixed-cultured groups was lower than that of the single-cultured groups. The viable cells of the mixed-cutured groups were remarkably increased until 3 days of storage, and after 6 days they were gradually decreased. The results of the sensory evaluation demonstrated acidic, salty and alcoholic flavors were significantly different among the groups. The single-cultured group without salt was significantly more acidic than the non-pasteurized control group. The mixed-cultured group with salt was significantly more alcoholic than the group without salt and control groups. The non-pasteurized control group was significantly more homogeneous than the mixed-cultured groups and single-cultured group with salt. Preference ranking test showed that flavor and overall acceptability of the fermented juices was significantly different among the groups. Flavor of the single-cultured group without salt was found significantly better than those of the groups with salt. With the respect of overall acceptability, the single-cultured group without salt was significantly more acceptable than the non-pasteurized control group and the mixed-cultured group with salt.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.12
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• pp.371-380
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• 2017

This paper aims to explore a comparative instructional effects among meaning-based communicative language teaching, input-enhanced FnF instruction and output-enhanced FnF instruction in order to optimize the teaching methods of target grammar and vocabulary. The experiment selected three homogeneous groups of 30 students in each group for the comparison: One comparative group with communicative language teaching, one input-enhanced FnF group and another output-enhanced FnF group. The result indicates that the input-enhanced group outperformed the comparative group in the grammar test with statistical significance and the output-enhanced group overweighted the comparative group in the vocabulary test. However, no significant statistical difference was found between the input-enhanced group and the output-enhanced group. The conclusion from the result could bear the following pedagogical implication: The general English education must use the eclectic method of adopting communicative language teaching with FnF of input-enhanced target grammar and output-enhanced target vocabulary to supplement the students with the basic vocabulary and grammar.

• Journal of The Korean Association For Science Education
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• v.20 no.1
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• pp.174-182
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• 2000

In this study, the effects of grouping by communication apprehension level in cooperative learning strategy applied to general science class and the difference between high and low communication apprehension levels were investigated. Three classes (N=112) were randomly assigned to two cooperative and one traditional learning groups. Students in two cooperative learning classes were grouped into homogeneous and heterogeneous groups with respect to their communication apprehension levels based on the test score of students' communication apprehension. After the instructions concerning the matter for 11 class hours, achievement, self-esteem, motivation to learn science. and student's perception to lack about communication ability and expectation about receiving help in cooperative learning processes were examined. Two-way ANOVA results revealed that there were no main and interactive effects in the scores of the achievement test. However, significant main effect of the treatment was found in the scores of the relevance and the satisfaction among four motivation sub-categories. In post-hoc comparison, the scores of the heterogeneous group were found to be significantly higher than those of the control group. For expectation about receiving help in cooperative learning processes, the scores of the heterogeneous group were significantly higher than those of the homogeneous group. Students in high communication apprehension level had significantly lower self-esteem and more perception to lack about communication ability than students in low level.

• Journal of The Korean Association For Science Education
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• v.20 no.1
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• pp.43-51
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• 2000

In this study, the effects of extraversion/introversion grouping and the differences between extroverts and introverts in cooperative learning strategy applied to general science class were investigated. Ninety-three 10th-graders were grouped into homogeneous and heterogeneous cooperative groups with respect to extraversion and introversion, and were taught about matter for 10 class periods. Prior to the instructions, three tests regarding the extraversion/introversion, logical thinking, and learning motivation were administered. After the instructions, their achievements, process skills, self-esteem, communication apprehension, and learning motivation were examined. Two-way ANCOVA results revealed that there were no main and interactive effects in the scores of the achievement and the process skills tests. However, significant interactive effect was found in the self-esteem. While the difference in the self-esteem of the introverts and the extroverts was small in the homogeneous group, the self-esteem of the extroverts was higher than that of the introverts in the heterogeneous group. The communication apprehension of the introverts was significantly lower than that of the extroverts. Students' perceptions to their group activities and group members were also studied.

• Women's Health Nursing
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• v.12 no.2
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• pp.97-105
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• 2006

Purpose: The purpose of this study is to verify the effects of the Qigong training program on the anxiety and labor pains of primipara. Method: The research subjects were a total of 60 primipara who consulted a doctor regularly concerning their antenatal care. Among them, 30 people were the experimental group, and the other 30 people were the control group, and were selected as homogeneous with the experimental group. The degree of anxiety and labor pains were measured by State-Trait Anxiety Inventory(STAI) and Graphic Rating Scale(GRS). SPSS WIN 11.0 was used for data analysis. Obstetric and general characteristics between experimental and control groups, and a homogeneity test of state and trait anxiety were done by both $X^2$ test and t-test. The hypothesis testing was analyzed by ANCOVA with a covariate of pretest value. Result: The first hypothesis, 'Primipara who join the Qigong training program have lower anxiety than those who do not join' was supported (F=28.8, p<.000). The second hypothesis, 'Primipara who join the Qigong training program have lower labor pain than those who do not join' was unsupported. Conclusion: It was verified that the Qigong training program was effective in alleviating anxiety; however it did not have any effect on relieving labor pain, so more in-depth research is needed later on.

• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.301-309
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• 2006

The main purpose of this study is to derive a regression equation that predicts the individual differences in activity energy expenditure (AEE) using accelerometer during different types of activity. Two subject groups were recruited separately in time: One is a homogeneous group of 94 healthy young adults with age ranged from $20\sim35$ yrs. The other subject group has a broad spectrum of physical characteristics in terms of age and fat ratio. 226 adolescents and adults of age ranged from $12\sim57$ yrs and fat ratio from $4.1\sim39.7%$ were in the second group. The wireless 3-axis accelerometers were developed and carefully fixed at the waist belt level. Simultaneously the total calorie expenditure was measured by gas analyzer. Each subject performed walking and running at speeds of 1.5, 3.0, 4.5, 6.0, 6.5, 7.5, and 8.5 km/hr. A generalized sensor-independent regression equation for AEE was derived. The regression equation was developed fur walking and running. The regression coefficients were predicted as functions of physical factors-age, gender, height, and weight with multivariable regression analysis. The generalized calorie estimation equation predicts AEE with correlation coefficient of 0.96 and the average accuracy of the accumulated calorie was $89.6{\pm}7.9%$.