• Journal of Mechanical Science and Technology
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• 제19권5호
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• pp.1080-1086
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• 2005

The preliminary design optimization of multi-stage spur gear reduction units has been a subject of considerable interest, since many high-performance power transmission applications (e.g., automotive and aerospace) require high-performance gear reduction units. There are multiple objectives in the optimal design of multi-stage spur gear reduction unit, such as minimizing the volume and maximizing the surface fatigue life. It is reasonable to formulate the design of spur gear reduction unit as a multi-objective optimization problem, and find an appropriate approach to solve it. In this paper an interactive physical programming approach is developed to place physical programming into an interactive framework in a natural way. Class functions, which are used to represent the designer's preferences on design objectives, are fixed during the interactive physical programming procedure. After a Pareto solution is generated, a preference offset is added into the class function of each objective based on whether the designer would like to improve this objective or sacrifice the objective so as to improve other objectives. The preference offsets are adjusted during the interactive physical programming procedure, and an optimal solution that satisfies the designer's preferences is supposed to be obtained by the end of the procedure. An optimization problem of three-stage spur gear reduction unit is given to illustrate the effectiveness of the proposed approach.

• 아동학회지
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• 제2권
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• pp.67-82
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• 1981

The present study was intended to investigate ecological characteristics of poverty areas in Seoul from the perspectives of children's development. More specifically, the objectives of the study are to examine environmental ecology of the poverty areas and it's potential psycho-social development of children. Three poverty areas and 150 children currently living in the are as were sampled ; 70 children from middle class families and 88 from lower class respectively. Focal ecological aspects surveyed family environment, outdoor play ground and facilities, and village housing structures. Psycho-social dimension's development dealt with in the study included children's perceptions of parental child rearing practices and role taking, and children's future perception and perspectives. Data were collected through interviews and observations using structured formats. Following results were obtained from the data : 1. Children from the poverty families showed a higher tendency to have working mothers than those from middle class. 2. The rate of having single room is higher for children from middle class by two times than from lower class. 3. Children from lower class tended to have less favorable perceptions of attitudes tote and their own families than those from middle class. 4. The likelihood of showing discrepancy in vocational choice for children between parents and children is higher for children from lower class and those from middle class. 5. Children from lower class tended to allot more time in playing with peers than those from middle class. 6. The size of outdoor play ground are inadequately poor both for middle and lower class children. The inadequateness is particularly severe for the lower class children, showing that the size and facilities of playing ground available for the child from lower class is less than half compared with those of the children from middle class.

• 대한한방소아과학회지
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• 제29권4호
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• pp.23-28
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• 2015

Objectives The purpose of this study is to examine the development of PBL Module and the possibility of the evaluation on the Korean medical Pediatrics class. Methods In this study, we examined the 32 case reports (four teams for three years) which were made by the Korean medicine school $4^{th}$ year students, who attended the discussion class. The student read the given materials and identified the purpose of the subjects and selected the learning issues, investigated them. After then they discussed the subjects and made the reports. Results The learning issues by students were similar, the students worked to study them with research papers, books, internet materials and personal subjects. After class, the students showed the change of their thoughts and they could accept the other one. Conclusions This study suggests it is possible that the development of PBL Module and the evaluation on the Korean medical Pediatrics Class.

• 한국가정과교육학회지
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• 제9권2호
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• pp.87-100
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• 1997

The purpose of this study were to investigate and no investigate and to compare perceptions of home economics teachers and educators regarding home economics student teaching pratice, thereby to provide fundamental information for improving home economics student teaching pratice. The specific objectives of this study were at follows. 1. To determine and compare the perceptions of home economics teachers and teacher educators regarding the importance and achievement of (1) the objectives of student teaching, (2) the experiences of student teaching, (3) procedures for selecting cooperating teachers, (4) roles and responsibilities of cooperating teachers, and (5) roles and responsibilities of university supervisors. 2. To identify problems and revisions about home economics student teaching pratice suggested by home economics teachers and teacher educators. The subjects in this study included 90 home economics teachers in 500 girls’middle schools and 13 teacher educators in 21 universities with home economics education department in Korea. For this study, the Habedi’s instruments were used through testing validity and reliability. The data of this study were analyzed by using mean, standard deviation, t-test, and content analysis. The results of this study were as follow；1. The areas with the difference of perceptions of the importance between the two groups were objectives of student teaching, experiences of student teaching, procedures for selecting cooperating teachers, and roles and responsibilities of cooperating teachers. 2. Regarding problems about home economics students teaching practice, home economics teachers indicated difficulty in performing adequate student teaching because of reduction in class hours, and lack of student teachers’positive attitude in performing student teaching, while teacher educators indicated having reluctancy of cooperating school to admit student teachers, and difference in experiences of student teachers because of disparity among cooperating schools. As solutions about the problems of home economics student teaching practice, home economics teachers suggested that student teaching course should be limited to the students qualified for teaching and that class observation and teaching practice in real class should be emphasized, while teacher educators suggested that student teaching should be performed adequately by providing institutions to control student teaching practice teacher should be made efficient by examining the scales of cooperating schools.

• Journal of Acupuncture Research
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• 제26권2호
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• pp.207-212
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• 2009

Objectives : The purpose of this report is to report the effect of acupotomy for patients with congestive heart failure. Methods: We treated 1 patient who has dyspnea due to congestive heart failure with acupotomy. To check the effect and satisfaction of acupotomy we used New York Heart Association class(NYHA class), Modified Borg Scalw Dyspnea Index(Borg Index), Baseline Dyspnea Index(BDI), Five-point Likert scale. Results : After 1 month of treatment, the patient felt much better in breathing, and had better score in NYHA class, Borg Index, BDI. Conclusions : This report demonstrates that acupotomy therapy has useful effect on congestive heart failure, but the more cases and researches are needed.

• 대한전기학회논문지
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• 제43권6호
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• pp.982-990
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• 1994

In this paper, we consider feedback-kinearizing control of brushless dc motors which have been increasingly used in high-performance servo applications, We completely characterize the whole class of the feedback controllers that enable the brushless dc motors to behave like linear systems but without torque ripple. The whole class of the feedback-linearizing controllers is characterized in the explicit form which contains a function to be chosen freely. The previously known controllers correspond to either the particular ones in our whole class of the feedback-Linearzing controllers or their truncated Fourier expansions. This free function can be used to achieve other control objectives as well as linear dynamic characteristics. Furthermore, our feedback-linearizing controllers can be easily determined from the measurement data of back EMF.

• 한국과학교육학회지
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• 제5권1호
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• pp.19-34
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• 1985

Teaching inquiry process is one of the most important objectives in science education. To promote students scientific process skills, a science teacher should encourage the students do something by themselves. One method for that purpose which has been used in many schools would be group experiment. The researcher has been experienced a lot of difficulties in controlling or guiding every group to finish the assigned experiment within the given class hour. Therefore, the researcher decided to select several leaders from students and trained them in advance of the given class hour. This leaders are expected to guide the remaining students in the class. As the result of this study, the classroom with and without student leaders showed very significant difference(P>0.001) in their achievement of scientific process skills. The experimental group also showed more positive attitude toward science. The researcher concluded that the use of student leaders is very effective in promoting scientific process skills. This method is also regarded very effective in a large class sized like Korean Schools.

• 대한가정학회지
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• 제32권2호
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• pp.255-263
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• 1994

The objectives of this study were : 1) to find research trends on lifestyles 2) to analyze the lifestyle patterns of middle class residents in Seoul and 3) to develop a standarized instrument to measure lifestyles. Questionnaires were administered to 1615 homemakers in Seoul, The statistics with the SPSS software package was used for factor analysis. The major findings were as follows: the lifestyles of middle class residents in Seoul were categorized into six patterns : Fashion oriented Interior Design Oriented Economy Concerned Simplicity in Eating Hobby Oriented and Health Concerned. A standarized instrument using validity and reliability testes for lifestyles was developed.

• 한국치위생학회지
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• 제21권6호
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• pp.813-820
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• 2021

Objectives: This study was conducted to verify the effectiveness of the VR-applied head and neck anatomy class and to be used as basic data for the development of a teaching method using VR in the basic dental hygiene field. Methods: A convenience sample was extracted from 128 students and graduates who completed the head and neck anatomy class at the department of dental hygiene at a university in Gwangju. From June 1 to July 31, 2021, an online survey was conducted on class attitude and satisfaction, and statistical analysis was performed using frequency analysis and independent sample t-test. Results: Class attitude (3.79), interest (3.64), attention (3.88), learning motivation (3.80), and achievement motivation (3.84) were all high in the head and neck anatomy VR application group (p<0.01). Satisfaction (3.99), relevance of class content (4.06) and class achievement (3.96) were high in the head and neck anatomy VR application group (p<0.01). The suitability of class attitude (3.65) and class content (sub-item of class satisfaction) (4.13) was high in the group with the 4th industrial revolution education experience (p<0.05). Conclusions: The effect of VR application in the head and neck anatomy class was confirmed to increase students' class attitude and satisfaction. In the basic dental hygiene curriculum, it will be necessary to develop and utilize teaching methods related to the 4th industrial revolution and VR application classes.

• Restorative Dentistry and Endodontics
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• 제38권2호
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• pp.79-84
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• 2013

Objectives: This study aimed to investigate the effect of clinical clerkship-associated achievements, such as performance of procedures at the student clinic, observation, and attitude towards a clerkship, on the objective structured clinical examination (OSCE) scores of dental students graduating in restorative dentistry. Materials and Methods: The OSCEs consisted of two stations designed to assess students' clinical skills regarding cavity preparation for a class II gold inlay and a class IV composite restoration. The clerkship achievements, consisting of the number of student clinical procedures performed, observation-related OSCE, and scores of their attitudes towards a conservative dentistry clerkship, were assessed. Correlation and multiple regression analyses were conducted. Results: The correlation coefficient between the OSCE scores for cavity preparation for a class II gold restoration and clerkship attitude scores was 0.241 (p < 0.05). Regarding a class IV composite restoration, OSCE scores showed statistically significant correlations with the observation (r = 0.344, p < 0.01) and attitude (r = 0.303, p < 0.01) scores. In a multiple regression analysis, attitudes towards a clerkship (p = 0.033) was associated with the cavity preparation for a class II gold inlay OSCE scores, while the number of procedure observations (p = 0.002) was associated with the class IV composite restoration OSCE scores. Conclusions: The number of clinical procedures performed by students, which is an important requirement for graduation, showed no correlation with either of the OSCEs scores.