• Journal of Korean society of Dental Hygiene
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• v.14 no.1
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• pp.59-65
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• 2014

Objectives : The purpose of the study is to investigate the awareness and influencing factors of class evaluation in dental hygiene students. This study will establish the measures for educational quality improvement and basic data for effective way of education. Methods : A self-reported questionnaire was filled out by 968 dental hygiene students in Busan, Gyeongnam, and Ulsan from August 26 to September 6, 2013. SPSS 19.0 was used for statistical analysis. Results : Senior students felt the necessity of class evaluation improvement. In class evaluation items by grade, evaluation entity was the most significant factor. The students answered that teaching sincerity was the most important factor in class evaluation. Conclusions : The students thought that class evaluation depended on the entity and sincerity of the class contents.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.199-215
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• 1996

A new Class-D series-loaded resonant inverter topology which can minimize the influences of the stray inductances is presented. In the conventional Class-D inverters, the stray inductances not only result in the overvoltage which gives the switches voltage stresses, but also in the high frequency resonant currents during turn-off transients. The new Class-D inverter is superior to the conventional Class-D inverters with respect to minimization of the problems caused by the stray inductances and is more suitable for high power and high frequency inverter systems such as induction heating. The validity of the new Class-D inverter is verified by simulation and experimental results.

• Journal of the Korean School Mathematics Society
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• v.3 no.1
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• pp.189-200
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• 2000

The purpose of this thesis is that the students understand the sentence stated math problems closely related to the real life and adapted the right solving strategies try to find the solution to a problem. The following research problem were proposed. 1. How repeated thinking lessons develop the understanding of problems and influence the usage of correct problem solving strategies and extensions of problem solving. 2. There are how much differences of achievement for each type of sentence stated problems by using comparative analysis of upper class, intermediate class, and lower class for each level between the experimental and comparative classes. In order to conduct this research the classes were divided into three different level - upper class, intermediate class and lower class. Each level include an experimental class and a comparative class. The two classes (experimental class and comparative class) of the same level were tested on the basis of class division record with the experimental class repeated learning papers for two weeks were used to guide the fixed thinking algorism for each sentence stated math problems. Eight common problems were chosen from a variety of textbooks : number calculation problems, velocity-distance-time problems, the density of a mixture, benefit problems, distribution problems, problems about working, ratio problems, the length of a figure problems. After conducting this research experiment The differences in achievement level between the experimental class and comparative class, were compared and analyzed through achievement tests made from the achievement test papers with seven problems, which were worth seventy points (total score). The conclusions of this thesis are as follows: Firstly, leaning activities through the usage of repeated learning papers for each level class produce an even development of achievement level especially in the case of the upper class learners, they have particular differences (between experimental class and comparative class) compared to the intermediate level and lower classes. Secondly, according to the analysis about achievement development each problems, learners easily accept the strategies of solution through the formula setting up to the problem of velocity -distance-time, and to the density of the mixture they adapted the picture drawing strategies interestingly, However each situation requires a variety of appropriate solution strategies. Teachers will have to employ other interesting solution strategies which relate to real life.

• The korean journal of orthodontics
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• v.9 no.1
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• pp.85-98
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• 1979

This investigation was designed to compare the craniofacial and dental morphology of class III malocclusion with that of normal occlusin in children, and to determine the incidence of various class III craniofacial skeletal patterns. The material selected for this study consisted in standard lateral cephalograms of eighty two Korean children, forty one boys and forty one girls, aged 10 through 12 years, having class III malocclusion, and forty two Korean children, twenty boys and twenty two girls, with normal occlusion in the same age. Using the tracings of the standard lateral cephalograms, various angular and linear measurements were recorded, tabulated and statistically analyzed, and then the class III craniofacial skeletal morphology was divided into various patterns by the degree of SNA and SNB, which respectively were below, within or beyond the normal range of those of normal occlusion. The following characteristics of the craniofacial and dental morphology of class III malocclusion were observed. 1. The cranial base length of class III malocclusion was smaller than that of normal occlusion, and the small saddle angle was a characteristic figure of class III malocclucion. 2. Maxillary length of class III malocclusion was smaller than that of normal occlusion, and point A was retropositioned relative to cranial base but not PNS in class III malocclusion. Maxillary base inclination was not significantly different between the two, but occlusal plane to palatal plane was small in class III malocciusion. 3. The mandibular body length shown no difference between the two, but the mandibular body positioned anteriorly relative to cranial base in class III malocclusion. Ramus height, gonial angle, and mandibular effective length were large in class III malocclusion. Mandibular plane angle and joint angle had no difference between the two, and occlusal plane to mandibular plane angle was large in class III malocclusion. 4. Maxillary incisor inclination was not significantly different between class III malocclusion and normal occlusion, but mandibular incisors positioned and inclined lingually and consequently interincisal angle was large in class III malocclusion. 5. Class III malocclusion was divided into six categories of craniofacial skeletal pattern. The most common class III pattern was found to be one in which the maxilla was within the normal range of prognathism while the mandible extended beyond this range. The pattern in which the maxilla was below the normal range of prognathism while the mandible was within this range was approximately one fifth of the class III sample.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.279-294
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• 1999

The level-based task learning had an effect on enhancing the math achievement of enrichment and ordinary classes. Besides, the analysis of mathematical attitude change showed that the level-based task learning took effect in the experimental class in every domain, including self-confidence, flexibility, will power, reaction and value, while it made little difference to the comparative class. The findings were as follows in detail. 1. The Outcome of the Achievement Test 1) The Enrichment Class In the first two tests, there were little differences in the enrichment class, But the disparity between the experimental and comparative classes became larger as this study advanced with 4.3 for the third test, 6.4 for the fourth and 6.1 for the fifth. 2) The Ordinary Class In the first to fifth achievement tests, the ordinary class made less difference than the enrichment class did. But there appeared some effect as this study progressed, since the mean grade disparity between the experimental and comparative classes was 2.1 for the first test, 3.5 for the second, 3.9 for the third, 4.4 for the fourth and 6.3 for the fifth. 3) The Supplementary Class The supplementary class showed no big difference in the first two tests. But, like the ordinary class, there was some effect with the lapse of the third 2.9 for the test, 3.2 for the fourth and 4.1 for the fifth. 2. The Change of Mathematical Attitude 1) The Experimental Class The task learning by level had a great deal of effect on the experimental class, as the pre-and post-comparative analyses showed that this class's grades were 5.1 for self-confidence, 10.8 for flexibility, 11.3 for will power, 9.7 for curiosity, 10.9 for reaction and 2.8 for value. 2) The Comparative Class The relative comparison between the comparative class and experimental class revealed that there was a hole effect on the comparative class. 3. The Outcome of Questionnaire Survey 1) They showed a positive reaction, as 40.1% of them answered the level-based task loaming served to raise their achievement, and 48.0% told so-so, and 11.9% replied they weren't helped by it. 2) The results after the experiment were;37.8% of the students say they under- stood practically everything while 12.6% of them say they under stood almost half. 3) The will to learn after the experiment shows dramatic changes between the two classes, The students in the enrichment class showed better will to learn than the students in the ordinary and supplementary classes did.

• Journal of Korean Academy of Nursing
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• v.20 no.1
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• pp.16-37
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• 1990

A cost analysis for hospitalized patients was carried out based upon Patient Classification System(PCS) in order to determine an appropriate nursing fee. The data were collected from 21 nursing units of three teaching hospitals from April 1 to June 30, 1989. first, all of the 22,056 inpatients were classified into mildly ill(Class Ⅰ), moderately ill(Class Ⅱ), acutely ill(Class Ⅲ), and critically ill(Class Ⅳ) by the PCS which had been carefully developed to be suitable for the Korean nursing units. Second. PCS cost accounting was applied to the above data. The distribution of inpatients, nursing costs, and nursing productivity were as follows : 1) Patient distribution ranged from 45% to class Ⅰ, 36% to class Ⅱ, 15% to class Ⅲ, and 4% to class Ⅳ, the proportion of class Ⅳ in ‘H’ Hospital was greater than that of the other two hospitals. 2) The proportion of Class Ⅲ and Ⅳ in the medical nursing units was greater than that of surgical nursing units. 3) The number of inpatients was greatest on Tuesdays, and least on Sundays. 4) The average nursing cost per hour was W 3,164 for ‘S’ hospital, W 3,511 for ‘H’ hospital and W 4,824 for ‘K’ hospital. The average nursing cost per patient per day was W 14,126 for ‘S’ Hospital, W 15,842 for ‘H’ hospital and W 21,525 for ‘K’ hospital. 5) The average nursing cost calculated by the PCS was W 13,232 for class Ⅰ, W 18,478 for class Ⅱ, W 23,000 for class Ⅲ, and W 25,469 for class Ⅳ. 6) The average nursing cost for the medical and surgical nursing units was W 13,180 and W 13,303 respetively for class Ⅰ, W 18,248 and W 18,707 for class Ⅱ, W 22,303 and W 23,696 for class Ⅲ, and W 24,331 and W 26,606 for class Ⅳ. 7) The nursing costs were composed of 85% for wages and fringe benefits, 3% for material supplies and 12% for overhead. The proportion of wages and fringe benefits among the three Hospitals ranged from 75%, 92% and 98% for the ‘S’, ‘H’, ‘K’ hospitals respectively These findings explain why the average nursing cost of ‘K’ hospital was higher than the others. 8) According to a multi- regression analysis, wages and fringe benefits, material supplies, and overhead had an equal influence on determining the nursing cost while the nursing hours had less influence. 9) The productivity of the medical nursing units were higher than the surgical nursing units, productivity of the D(TS) - nursing units was the lowest while the K(Med) - nursing unit was the highest in 'S' hospital. In ‘H’ hospital, productivity was related to the number of inpatients rather than to the characteristics of the nursing units. The ‘K’ hospital showed the same trend as ‘S’ hospital, that the productivity of the medical nursing unit was higher than the surgical nursing unit. The productivity of ‘S’ hospital was evaluated the highest followed by ‘H’ hospital and ‘K’ hospital. Future research on nursing costs should be extended to the other special nursing areas such as pediatric and psychiatric nursing units, and to ICU or operating rooms. Further, the PCS tool should be carefully evaluated for its appropriateness to all levels of institutions(primary, secondary, tertiary). This study took account only of the quantity of nursing services when developing the PCS tool for evaluating the productivity of nursing units. Future research should also consider the quality of nursing services including the appropriateness of nursing activities.

• Kyungpook Mathematical Journal
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• v.49 no.2
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• pp.203-209
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• 2009

In this paper we study some spectral properties of the class (y) operators and we will investigate on the relation between this class and other usual classes of operators.

• Journal of the Korean Society of Earth Science Education
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• v.8 no.3
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• pp.346-354
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• 2015

The purpose of this study was to be a help with designing science curriculum and developing science programs for the science gifted students by comparing their preferences about science class forms and class environments between science gifted students and normal students. For this study, 2 classes of science gifted students and 5 classes of normal students in 4th, 5th grade joined in this survey and their preferences about science class forms and class environments were checked using questionnaire. As a result, the following findings were obtained. First, in the area of class form, from comparing their preferences about teaching content domain, science gifted students showed meaningful higher preferences in all factors such as clarification, structuralization, thinking of high level and diversification. In comparing their preferences about teaching process domain, science gifted students also showed meaningful higher preferences in all factors such as diversification and self directed learning. Second, in the area of class environment, from comparing their preferences about classroom domain, science gifted students showed meaningful higher preferences in all factors such as teacher's support and rule and organization. In comparing their preferences about mentality domain, science gifted students also showed meaningful higher preferences in all factors such as influence of friends and parents. Third, in science gifted students, from comparing their preferences by gender about science class forms and class environments, female students showed meaningful higher preferences in factors of clarification. And in other factors females showed similar preference tendency with male students. In normal students' comparing, female students showed meaningful higher preferences in factors of teacher's support. And male students showed meaningful higher preferences in factors of high level thinking and influence of friend and influence of parents.

• The korean journal of orthodontics
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• v.42 no.4
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• pp.190-200
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• 2012

Objective: The displacement of the hyoid bone (HB) is a critical biomechanical component of the swallowing function. The aim of this study was to evaluate the swallowing-induced vertical and horizontal displacements of the HB in subjects with 2 different magnitudes of skeletal Class III malocclusion, by means of real-time, balanced turbo-field-echo (B-TFE) cine-magnetic resonance imaging. Methods: The study population comprised 19 patients with mild skeletal Class III malocclusion, 16 with severe skeletal Class III malocclusion, and 20 with a skeletal Class I relationship. Before the commencement of the study, all subjects underwent cephalometric analysis to identify the nature of skeletal malformations. B-TFE images were obtained for the 4 consecutive stages of deglutition as each patient swallowed 10 mL of water, and the vertical and horizontal displacements of the HB were measured at each stage. Results: At all stages of swallowing, the vertical position of the HB in the severe Class III malocclusion group was significantly lower than those in the mild Class III and Class I malocclusion groups. Similarly, the horizontal displacement of the HB was found to be significantly associated with the severity of malocclusion, i.e., the degree of Class III malocclusion, while the amount of anterior displacement of the HB decreased with an increase in the severity of the Class III deformity. Conclusions: Our findings indicate the existence of a relationship between the magnitude of Class III malocclusion and HB displacement during swallowing.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.216-224
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• 2013

The within-class variance of Otsu's method is moderate but improper in expressing class statistical distributions. Otsu's method uses a variance to represent the distribution of each class. The variance utilizes a distance square from the mean to a data. This process is not proper in denoting a real class statistical distribution because of the distance square. In this paper, to express more exact class statistical distributions, the within-class standard deviation as a criterion for threshold selection is proposed and then the optimal threshold is determined by minimizing it. In order to have validity, it is shown through the experimental results that the proposed method was more superior to the counterparts.