• Journal of Nutrition and Health
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• v.27 no.4
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• pp.336-346
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• 1994

balance and to estimate daily energy requirement in 43 Korean female college students maintaining their usual diet and activity level. Energy intake and expenditure were measured in two separate periods about one month apart, each period lasting for 3 days. All the subjects participated in both periods. Energy intake was assessed by two methods ; weighed diet record and duplicate portion analysis of diet minus fecal and urinary excretion. Mean daily energy intake level calculated from diet records was 28.5 kcal/kgB.W(1, 476 kcal/day), and similar to the level of 27.8 kcal/kgB.W(1, 438 kcal/days) obtained from the chemical analysis of duplicate portions. Mean daily energy expenditure, calculated from activity records of each subject, was 34.6 kcal/kgB.W, or 1.39 times BMR, which corresponds to light activity level. Mean daily energy balance of subjects was -5.9 kcal/kgB.W. Mean daily requirement of energy, calculated from the activity records of the subjects, was 34.6 kcal/kgB.W, similar to the level of the Korean RDA for light activity level. The results of this study indicate that 1) the activity level of the study subjects corresponds to the sedentary level ; 2) present Korean RDA for energy for light activity is adequate for the subjects ; and 3) the subjects should increase their energy intake since they are largely in negative energy balance.

• Journal of Nutrition and Health
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• v.27 no.10
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• pp.1070-1077
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• 1994

The purpose of this study was to measure the counseling effects for diabetes mellitus patients. To measure the effects of the nutrition counseling, 40(13 men and 27 women) outpatients with diabetes mellitus were selected and they were randomly assigned to either the counseling group or non counseling group. Twenty-one counseling group patients received nutrition counseling weekly for 6 weeks and 19 patients served as non counseling group(control group) did not received counseling over same study period. The results of this study can be summerized as follows : 1) The food attitude score of the counseling group significantly increased from 61.9$\pm$15.9 prior to counseling to 87.0$\pm$7.8 after counseling (p<0.001). 2) Fasting blood glucose level and postgrandial blood glucose level also showed significant difference between two groups(p<0.01). In the counseling group, the fasting blood glucose level significantly decreased from 163.5$\pm$48.6mg/dl to 142.3$\pm$40.6mg/dl(p<0.01), and the postgrandial blood glucose level significantly decreased from 281.3$\pm$105.1mg/dl(p<0.001). 3) There was a significant difference of glycosylated hemoglobin between the two groups(p<0.005), and the glycosylated hemoglobin level of counseling group significantly decreased from 11.2$\pm$2.9% to 9.7$\pm$3.6%(p<0.005). 4) There was a significant correlation between the food attitude score difference and the glycosylated hemoglobin level difference in counseling group(p<0.05).

• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.85-96
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• 1994

In this study, 24 curved resin blocks were prepared by one of the following four methods: 1) Conventional technique using K-flexo files 2) Step-back technique using K-flexo files 3) Crown-down technique using K-flexo files 4) Canal Master instrumentation using Canal Master Resin blocks were sectioned, photographed, and evaluated the mean centering ratio and the mean area of dentin removed before and after the instrumentation. The results were as follows : I. the mean centering ratio 1. In the level 1 and level 3, there was no significant difference in the mean centering ratio. 2. In the level 2, Step-back technique showed the worst mean centering ratio among the tested groups(p<0.001) and there was no significant difference between the other three groups. 3. In the level 4, Canal Master instrumentation and Step-back technique showed better mean centering ratio than the other two techniques(p<0.001) and there was no significant difference between the two techniques. II. the mean area of dentin removed 1. In the level l and level 3, there was no significant difference in the mean area of dentin removed. 2. In the level 2, Canal Master instrumentation removed less dentin than the other three techniques(P<0.01). 3. In the level 4, Crown-down technique removed less dentin than the other three techniques(P<0.05).

• Journal of Oriental Neuropsychiatry
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• v.30 no.3
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• pp.177-184
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• 2019

Objectives: This purpose of this study was to examine the level of communication and clinical skills of Korean medical students according to the participatory method of role playing during medical education. Methods: A total of 100 fourth grade students from the Korean Medical College of Dongshin University in 2018 and 2019 were divided into two groups: Role players and scenario writers. After performing their role-playing, they were asked to complete questionnaires regarding two categories-communication and clinical skills-, consisting of 10 items. Results: 1. Communication skills were measured at approximately 80% of the expected level, and the level difference was shown in detail. 2. Clinical skills were measured at approximately 75% of the expected level, and the level difference was shown in detail. 3. The level of communication skills and the level of clinical skills according to the participatory method did not differ significantly. Conclusions: Writing scenarios in role playing can be observed as having the same effect on communication and clinical skill levels as acting.

• Geomechanics and Engineering
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• v.18 no.1
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• pp.71-83
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• 2019

This investigation presented conventional triaxial and creep-permeability tests on sandstones considering thermally-induced damage (TID). The TID had no visible effects on rock surface color, effective porosity and permeability below $300^{\circ}C$ TID level. The permeability enlarged approximately two orders of magnitude as TID increased to $1000^{\circ}C$ level. TID of $700^{\circ}C$ level was a threshold where the influence of TID on the normalized mass and volume of the specimen can be divided into two linear phases. Moreover, no prominent variations in the deformation moduli and peak strength and strain appeared as TID< $500^{\circ}C$ level. It is interesting that the peak strength increased by 24.3% at $700^{\circ}C$ level but decreased by 11.5% at $1000^{\circ}C$ level. The time-related deformation and steady-state creep rate had positive correlations with creep loading and the TID level, whereas the instantaneous modulus showed the opposite. The strain rates under creep failure stresses raised 1-4 orders of magnitude than those at low-stress levels. The permeability was not only dependent on the TID level but also dependent on creep deformation. The TID resulted in large deformation and complexity of failure pattern for the sandstone.

• Journal of the Korean Chemical Society
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• v.64 no.5
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• pp.267-276
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• 2020

This study analyzed the level of chemistry teachers' cognition related to two types of acid-base models taught in secondary schools. For the purpose, a questionnaire was developed to identify teachers' cognitions based on previous studies that analyzed the 'Ignorance' of each model. The questionnaire consisted of two items, one related to acid and base reactions and one related to acid and base dissociation, which suggested inconsistencies between the two models. The subjects were 15 chemistry teachers, and as a result, teachers' cognitions were analyzed at four levels. The four levels are: if they don't know the two models, if they only understand one model, if they understand the two models, and perceived the 'Ignorance' of one model, and if they understand the two models and perceived the 'Ignorance' of the two models. The largest proportion of teachers understood the two models and perceived the 'Ignorance' of one model. However, the proportion of understanding the two models and perceiving the 'Ignorance' of the two models was very small. Through this, we argued that efforts to increase the level of chemistry teachers' cognition of the model and 'Ignorance' were necessary.

• Journal of Power Electronics
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• v.18 no.2
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• pp.627-639
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• 2018

The fact that the reliability of IGBTs has become a more and more significant aspect of power converters has resulted in an increase in the research on the open circuit (OC) fault location of IGBTs. When an OC fault occurs, a zero-current phenomena exists and frequently appears, which can be found in a lot of the existing literature. In fact, fault variables have a very high correlation with the zero-current interval. In some cases, zero-current interval actually decides the most significant fault feature. However, very few of the previous studies really explain or prove the zero-current phenomena of the fault current. In this paper, the zero-current phenomena is explained and verified through mathematical derivation, based on two-level and three-level NPC static var generators (SVGs). Mathematical models of single OC fault are deduced and it is concluded that a zero-current interval with a certain length follows the OC faults for both two-level and NPC three-level SVGs. Both inductive and capacitive reactive power situations are considered. The unbalanced load situation is discussed. In addition, simulation and experimental results are presented to verify the correctness of the theoretical analysis.

• Proceedings of the Korean Association for Survey Research Conference
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• 2002.11a
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• pp.255-274
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• 2002

We classify rotation sampling designs into two classes. The first class replaces sample units within the same rotation group while the second class replaces sample units between different rotation groups. The first class is specified by the three-way balanced design which is a multi-level version of previous balanced designs. We introduce an extended generalized composite estimator (EGCE) and derive its variance and mean squared error for each of the two classes of design, cooperating two types of correlations and three types of biases. Unbiased estimators are derived for difference between interview time biases, between recall time biases, and between rotation group biases. Using the variance and mean squared error, since any rotation design belongs to one of the two classes and the EGCE is a most general estimator for rotation design, we evaluate the efficiency of EGCE to simple weighted estimator and the effects of levels, design gaps, and rotation patterns on variance and mean squared error.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.1
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• pp.41-48
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• 2020

Currently, the industry uses MODBUS communication method using RS485 as a communication method used when constructing distributed equipment and networks. However, this method has a rather good transmission and reception distance, but has a disadvantage of being a half-duplex communication method. Therefore, there is a great need for a full-duplex communication method that can simultaneously transmit and receive two-wire communications. Therefore, in this paper, we propose a new communication hardware equipment that can implement full-duplex communication method by communication signal level to overcome the disadvantage of communication speed. The proposed communication hardware is a structure that can transmit and receive at the same time on the same communication line in two equipments communicating in a two-wire system. The characteristic of this communication hardware is that the transmitter generates two-level signal for data transmission, but the receiver generates three-level electric signal according to the status of the transmission data generated by the receiver. The data transmission signal information of the receiver is present at the same time. Therefore, the receiving side can analyze the received signal based on the information on the current transmission signal and can analyze the signal only in the two communicating devices, so it can be seen that the communication security is very excellent.

• Journal of the Korean Home Economics Association
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• v.30 no.2
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• pp.159-169
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• 1992

This study attempted to analyze the psychological anxiety of middle-aged men who expect to retire in order to bring up the problems of present retirement system, and suggest more desirable solutions connected with social welfare. The subjects of this study consisted of "non retirement group", aged 40-44(N=70) and "retirement group", aged 50-54(N=60) who were full-time employees in the small and medium enterprizes. The psychological anxiety levels of the two groups were assessed by the Spielberger's State-Trait Anxiety Inventory(STAI) composed of 40 items. The major findings are as follows. There were significant differences in both trait and state anxiety between the two groups. The retirement group reported the higher level of both trait and state anxiety than the non retirement. And there was significant difference in "increased anxiety level by retirement"(state anxiety-trait anxiety) between the two groups. The retirement group reported the higher level of increased anxiety than the non retirement group. The state anxiety of the retirement group was significantly different by the retirement-related factors such as health state, the presence or absence of leisure activity and plan for later life, etc. The opinion of the two groups on the present retirement system was generally negative. The two groups prefered the voluntary retirement to involuntary retirement and considered that the retirement time must be prolonged to the age of 60 or 65.