• Journal of Korean Elementary Science Education
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• v.23 no.1
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• pp.27-36
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• 2004

This paper aims to examine how well university students, who are going to be primary school teachers, understand the International System of Units (SI), focusing on seven basic units such as 'm', '㎏', '㏖', 'A', 'K', 's', 'cd'. This study specifically investigates whether the students know the seven units and understand their uses and how they read and learn them. The subjects were 1030 students from the University of Education in Jinju, Geongsangnamdo. Data was collected through a questionnaire which was designed by this researcher and checked by an authority, and the frequency and percentage of reponses to each question were obtained and analysed. Findings show all the students knew very well that 'm' and '㎏' are included in the seven units, compared to the others which low percentage of the students considered as the elements. In terms of understanding of use, the units of the length 'm', the mass '㎏', and the time 's' are well understood, presumably, because they are often used in ordinary life and school, while the amount of substance '㏖', the electric current 'A', the thermodynamic temperature 'K', and the luminous intensity 'cd' are not as well understood. It is probably because 'A', 'cd', and 'K' are hardly used in everyday life. With respect to reading the units, the subjects read 'm', '㎏', '㏖', and's' much better than the others. As for the source of learning them, most students answered they learned them in schools, which implies school education is very important. From these results it is concluded that school education should be accompanied with use in everyday life for understanding and using the units. SI Base Units understanding was investigated by an academic year. According to this investigation, generally the right answer rate differed 4<2<3<1 by an academic year in order. For the Senior, Sophomore appeared the right answer rate more high. because, they learned before in deepening or elementary course on chemistry and physics related with SI Base Units. On the other hand, for the junior answered low rate by this reason that they couldn't remember about SI Base Units that learned before. For the Freshman appeared low rate by this reason that they were not learned or graduated from the department of liberal art in high school.

• The Mathematical Education
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• v.50 no.2
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• pp.213-231
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• 2011

The purpose of this study is to analyze the 6th graders' understanding of the concepts of variable on various aspects of school algebra. For this purpose, the test of concepts of variable targeting a sixth-grade class was conducted and then two students were selected for in-depth interview. The level of mathematics achievement of the two students was not significantly different but there were differences between them in terms of understanding about the concepts of variable. The results obtained in this study are as follows: First, the students had little basic understanding of the variables and they had many cognitive difficulties with respect to the variables. Second, the students were familiar with only the symbol '${\Box}$' not the other letters nor symbols. Third, students comprehended the variable as generalizers imperfectly. Fourth, the students' skill of operations between letters was below expectations and there was the student who omitted the mathematical sign in letter expressions including the mathematical sign such as x+3. Fifth, the students lacked the ability to reason the patterns inductively and symbolize them using variables. Sixth, in connection with the variables in functional relationships, the students were more familiar with the potential and discrete variation than practical and continuous variation. On the basis of the results, this study gives several implications related to the early algebra education, especially the teaching methods of variables.

• East Asian mathematical journal
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• v.32 no.4
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• pp.565-587
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• 2016

The purpose of this study was to analyze the understanding of the meaning of fraction division and fraction division algorithm of elementary mathematical gifted students through the process of problem posing and solving activities. For this goal, students were asked to pose more than two real-world problems with respect to the fraction division of ${\frac{3}{4}}{\div}{\frac{2}{3}}$, and to explain the validity of the operation ${\frac{3}{4}}{\div}{\frac{2}{3}}={\frac{3}{4}}{\times}{\frac{3}{2}}$ in the process of solving the posed problems. As the results, although the gifted students posed more word problems in the 'inverse of multiplication' and 'inverse of a cartesian product' situations compared to the general students and pre-service elementary teachers in the previous researches, most of them also preferred to understanding the meaning of fractional division in the 'measurement division' situation. Handling the fractional division by converting it into the division of natural numbers through reduction to a common denominator in the 'measurement division', they showed the poor understanding of the meaning of multiplication by the reciprocal of divisor in the fraction division algorithm. So we suggest following: First, instruction on fraction division based on various problem situations is necessary. Second, eliciting fractional division algorithm in partitive division situation is strongly recommended for helping students understand the meaning of the reciprocal of divisor. Third, it is necessary to incorporate real-world problem posing tasks into elementary mathematics classroom for fostering mathematical creativity as well as problem solving ability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.478-485
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• 2003

Today, although there have been high technical developments of a compressor in the respect of its capacity, it has been so hard to develop in the respect of vibration and noise because mechanical structure of it has originally numerous vibration and noise. However, if we can grasp the point of systematic phenomena of vibration and noise through the understanding of dynamic characteristics in mechanical equipment, it may be possible to consider countermeasures. In this study about a reciprocal compressor, the part of its machinery is modeled as rigid body, and the part of its spring is modeled as flexible body, and then they are analyzed by DADS. Each rigid body and spring are connected with joint torque of a motor is applied to shaft, and pressure is applied to a piston so that a compressor can be revolved. Based on this modeling, influence of a compressor's vibration is analyzed through changes of offset, connecting rod and crank radius In the case of weight balance, it I produced after re-design, and then changes of vibration of a compressor's inside are checked through experiments. These analysis data may help set measures of reducing vibration of a reciprocal compressor.

• Journal of Hydrogen and New Energy
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• v.27 no.3
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• pp.311-317
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• 2016

This paper presents the flow characteristics of a ball valve used for a gas pipeline. Understanding of the internal flow of a ball valve is an important to analyze the physical phenomena of the valve. Present experimental study was performed by IEC 60534-2-3, the international standard for an industrial control valve testing procedure. Pressure measured at upstream and downstream of the valve, flow-rate and gas temperature passing the inside of the gas pipeline were measured with respect to valve opening rates. Throughout the experimental measurement of the ball valve, empirical equation of the pressure drop between the ball valve according to the mass flow rates is successively obtained using a polynomial curve fitting method. In addition, flow coefficient for determining the valve capacity is also analyzed with respect to valve opening rates using the curve fitting method.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.E
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• pp.1-18
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• 1996

In this review, the significance of terrestrial ecosystems in the global sulfur budget has been reviewed based on the currently available databases covering the topic. In the section 1, we describe our current understanding of natural sulfur cycle in relation to most well-known natural reservoir, oceanic environment. The sections 2 and 3 provide the fundamental pictures of the rerrestrial sulfur cycle with respect to the relative importance of its individe the fundamental pictures of the terrestrial sulfur cycle with respect to the section 3, previously reported flux values for several major sulfur gases are presented for each reservoir and are intercompared to derive representative fluxes for the respective environment. In the section 4, source mechanisms for volatile sulfur species are dealt for both microscale and macroscale processes leading to their productions. In the section 5, environmental factors controlling the exchange of biogenic sulfur gases across the air-surface have been discussed. In the section 6, environmental fate of sulfur gases released into the atmosphere has been described. Finally in tie section 7, as concluding remarksm we discuss directions and suggestions to overcome various limitations encountered from previous measurement investigations of natural sulfur cycle in diverse natural ecological systems.

• Women's Health Nursing
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• v.21 no.2
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• pp.139-149
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• 2015

Purpose: This study was to define and analyze the expectations of middle-aged woman to their spouse. Methods: A sample of 39 middle-aged women was recruited from the workplace, religious organization and acquaintances. The survey was conducted with participants using self-reported questionnaire. The data were analyzed using Q methodology. Results: There were four different types of expectations of middle-aged women. First type was "Collaborative and self-development type," meaning that women developed self and were collaborated with their family or spouses. The second type was "Maintain their own life" meaning that women recognized and maintained their expertise without interference from their spouses. The third one was "Respect for the inner value" meaning that women gave continued respect and understanding their inner value. The last one was "Realistic acceptance" meaning that women kept the current situation without implementing new self-development type. Conclusion: There is a subjective structure within the types of expectations of middle-aged women for a life of happiness to the spouse.

• Journal of Korean society of Dental Hygiene
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• v.20 no.1
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• pp.107-116
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• 2020

Objectives: This study applied the co-orientation model to investigate the degree to which dental hygienists and dentists recognize the efficiency of dental hygienists' non-surgical periodontal therapy work; the basic data can be provided as a systematic arrangement that can be applied and extended to dental clinics to raise mutual understanding. Methods: Independent sample t-tests, one-way ANOVA, and paired t-tests were conducted with a total of 888 subjects (530 dental hygienists and 358 dentists) using SPSS Statistics 22.0. Results: The analysis showed that, dental hygienists had higher recognition of the efficiency of their work (p<0.001) than dentists, with respect to all items(p>0.05). With respect to subjective agreement, dental hygienists estimated lower recognition among dentists than other dental hygienists and dentists estimated higher recognition among dentists than dental hygienists. With respect to accuracy, dentists' estimation was lower than the actual recognition among dental hygienists and dental hygienists' estimation was higher than the actual recognition among dentists in all cases except the efficiency of dental hygienists' patient education work and constant learning. Conclusions: There was wide gap between dental hygienists and dentists in recognition of the efficiency of dental hygienists' non-surgical periodontal therapy work. Actions must be taken to raise mutual understanding between dental hygienists and dentists regarding dental hygienists' non-surgical periodontal therapy work, to spread this recognition throughout the dental industry, and to implement systematic support at dental clinics.

• Women's Health Nursing
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• v.19 no.4
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• pp.242-253
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• 2013

Purpose: The purpose of this study was to develop a scale to assess immigrant women's needs for pregnancy and postpartum adaptation and to test the reliability and validity of the scale. Methods: To construct scale items, critical issues and difficulties associated with pregnancy and postpartum adaptation of immigrant women were identified and categorized through a literature review. Fifty-two scale items were constructed, and data for validity and reliability testing was collected with a questionnaire survey from 367 immigrant women. Data were analyzed with descriptive statistics, factor analysis, and reliability coefficients. Results: The final measurement scale to assess immigrant women's pregnancy and postpartum adaptation consisted of 48 items and 7 factors (adaptation to daily activity during pregnancy, cross-cultural understanding and personal respect, understanding of the process of pregnancy and delivery, baby rearing and family support, physical and emotional adaptation after childbirth, nutrition during pregnancy, and sexual life adaptation). The seven factors accounted for 64.26% of the variance, and Cronbach's ${\alpha}$ was .96. Conclusion: The scale developed by this study is a reliable and valid instrument and can be used to assess needs of pregnancy and postpartum adaptation and can be utilized in providing nursing interventions for immigrant women.

• Journal of Fashion Business
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• v.3 no.2
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• pp.37-47
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• 1999

In the 17th century, Europe had changed from medieval feudalistic ages into an absolute monarchy taking Catholicism and absolute monarchism together. On the other hand, Holland achieved prosperity in economy, culture, and arts through gradual enlightment of the people by winning independence from Spain, and religious reformation. The culture dress and its ornaments at the time was led by the governing class such as royal families and its aristocracy in Europe, while Holland, united republic country at the time, brought civil costume nationwide wholly by civil class and its effect to other neighboring countries in Europe. In addition, the origin of modern dress and its ornaments dates back to that time. Moreover, civil-looking dutch paintings found its sources in routine daily life and became realistic. With this respect, in this research, we put our purpose of the research in making a better and more understanding of the modern costume and its ornaments and exploring the spirit of human beings by analyzing dutch civil costumes shown in these artistic works. It is very important that this research is rather renovational comparing with prior ones focused on those of ruling classes. As a result of the research, the distinguished parts of the civil costumes appeares as following beauties. First, functional beauty was respected such as natural waist line, peplum, gather of the skirt and sleeve, apron, head towel were some of the examples to those in their costumes and its ornaments. Second, with respect to humanity under rough natural surroundings and long struggle with outside tribes, humanity of costume was brought by optimistic and even free mind to them. The three quater sleeve showed wrist and deep-cut decollete in their dress and ornaments. Third, with respect to simplicity, religious effect on the leading civil class demanding self-abstinence, frugality, and thrift in their way of life resulted in black-tone simple costumes with white collar in their costumes and its ornaments.