• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.17-24
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• 2010

This study was performed to make a close inquiry into a pseudo 3-dimensional structure of the liquid-propellant spray emerging from nonimpinging-type injector. Spray configuration near the injector exit was captured by a high-speed camera, and then its periodic phenomena (shedding) was observed. Detailed spatial structure of spray was investigated by spray characteristic parameters (velocity, diameter, volume flux, etc.) with the aid of a Dual-mode Phase Doppler Anemometry (DPDA). Experiment was carried out at various locations along the geometric axis of the nozzle orifice and on the plane normal to the spray stream with the injection pressures of 17.2 to 27.6 bar.

• Journal of Korean Elementary Science Education
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• v.32 no.3
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• pp.225-238
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• 2013

The purpose of this study is to find out The Effects of the Learning Motive, Interest and Science Process Skills using the 'Light' Unit on Science-based STEAM. As the subject, 2 classes in the 6th grade of G elementary school located in Busan were selected. Through the pre/post inspection design between experiment and comparison class, the units of science courses in the first semester of 6th grade '1. Light' were applied. The results were as follows: Firstly, it was observed that it would have a meaningful effect to improve the learning motive of students who performed STEAM education. Secondly, it was observed that it would have a meaningful effect to improve the interest of students who performed STEAM education. Especially, the results of 'attention', 'relevance', 'confidence' and 'satisfaction' in the experimental class were higher than those of students in the comparative class. The experimental class gave a positive effect on the 'attention', 'confidence' and 'satisfaction'. According to statistical analysis, this result is meaning. Thirdly, the test on science processing skills showed that there was not statistic meaningful differences between the two groups. But, in the sub-parts, there was statistic meaningful differences between the two groups on the 'integrated inquiry ability'.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.719-723
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• 2006

House dust mite was the most important cause of allergic asthma and rhinitis. More than 70% of Korean children and about 50% of adult with respiratory allergy were sensitive to house dust mite. This experiment was indoor environment in house and house dust mite existence inquiry. From 23rd December 2005 to 28th February 2006, dust samples were collected from the bedclothes by a vacuum cleaner and air sampler And the levels of Der f1 and Der p1 were determined by ELISA((Enzyme-Linked Immunosorbent Assay). The results were as follows : 1 The dust mites allergy contaminations of bedclothes in house were higher than international standards(2000 ng/g). 2. In type of dust mite, the Korean house the almost have the D. farinae other than D. pteronyeeinus of mite. 3. The Der f1 and Der p1 levels per gram of dust from the bedclothes were 2074.99 ng on average, but they did not exist in air. The concentrations of house dust mite were significantly high in the bedclothes. This results suggest that the bedclothes have enough concentrations of dust mites to develop the sensitization. The control of indoor environment should be emphasized to prevent the sensitization by the repeated exposure to dust mite.

• Journal of The Korean Association For Science Education
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• v.11 no.1
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• pp.97-115
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• 1991

The purpose of this study is in making a important way for in-service training of science teacthers. So the study was carried out to analyze the text books of in-service training school in Gyeongnam, Kyungpook, Junpook province and Pusan city and to survey teacher's opinion by questonnaires collected from teachers in Gyeongnam province. The result abtained are as follows : 1. The contents of. tire text books for in-service training course have very critical defference at each province. 2. Most of teachers wanted to get more updating information of the science and more comprehensive knowledge of higher level' of science subject. 3. In order to obtain comprehensive basic concept, develop of inquiry ability, and promote of scientific attitude, the thinking experiment which is selected to experimental subjects of secondary school are need to be selected. 4. The new text-book model for in-service training course should be developed, and the finnancial support will be required to develop such a text.

• Journal of Korean Elementary Science Education
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• v.27 no.2
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• pp.102-116
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• 2008

In their teaching practice, teachers encounter multi-dimensions of pedagogical challenges. The recognition and reflection on these challenges is crucial to advance our science teaching. This study looked into science teachers' dilemmas of their teaching practical work through their written cases. Dilemma cases are teachers' narratives organized around important events of teaching and learning. It can reveal teachers' situated cognition and be used as lens to investigate complex realities of science teaching and learning. 26 pre- and in-service elementary teachers' dilemma cases of science practical work were carefully collected and analysed to interpret what constitute tensions in elementary science practical works. They were largely grouped into three: Curriculum and Institutional Relevance, Students Relevance, Nature of School Experiments Relevance and divided into 7 subheadings: 'Authority of Curriculum(textbook)', 'Disappointment at external support', 'Students' interests and safety', 'Students' unscientific and inert attitude', 'Difficulty of showing expected results', 'Generalization through experiment', 'Knowledge acquisition and authentic inquiry'. Each dilemma was interpreted in terms of the tensions which constitute contradictory beliefs, values, expectation and realities. These dilemmas enabled to expose actual conditions of elementary science practical work and teachers' challenges otherwise can not be seen easily. Science teacher educators also can get some implications to overcome the gap between theory and practice in their teacher education.

• Journal of Korean Elementary Science Education
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• v.24 no.4
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• pp.435-442
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• 2005

For this study we conducted a survey far elementary students from 3rd to 6th grade. We performed a frequence test using statistic program and the cross-tabs between gender and grade. We then conducted a thorough interview with the students, after constructing several meaningful questions reflecting the results of survey. As a result of this study, it was critical to arrange interesting inquiry activities in order to foster student's preference for science and attract them to get involved in the science class. We found that teachers were needed to be more flexible to make a group during the classes and teachers would succeed to reflect student's characteristics. In addition, it is necessary for the teachers to refrain from excessive advising or immoderate interrupting student's experiment activity. We conclude that only when the improvements in the curriculum for science education should be made, teachers would allow students to recognize its significances by themselves, and let them follow the inquiring process during the laboratory class for themselves.

• Journal of Korean Elementary Science Education
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• v.38 no.2
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• pp.203-215
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• 2019

The purpose of this study is to clarify the roles of laboratory work in school. Twenty-one literatures were identified about roles of laboratory work in school by applying criteria such as published in CI level journals or used as a reference over 100 times during 1960-2017. Twenty-one literatures were reviewed according to periods such as 1960-1989, 1990-2003, and 2004-2017, and identified the roles of laboratory work in school that commonly presented in more than two literature. Seven roles of laboratory work in school identified were as follows (a) learning scientific knowledge, (b) enhancing attitude toward science, (c) learning scientific inquiry methods, (d) acquiring skills to use specific laboratory instruments, (e) enhancing scientific attitude, (f) understanding the nature of science(NOS), and (g) providing opportunity to experience natural or scientific phenomena. The results of this study can be used to provide school teachers and students a clear meaning of the roles of laboratory work in school.

• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.73-81
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• 2007

The purpose of this study was to find out chemistry teachers' perceptions on the aims and characteristics of the chemistry I course from the 7th national curriculum by means of investigating how frequently particular learning contents were selected and what the teachers' teaching styles were in order to find out how effectively teachers were working with the 7th national curriculum in teaching. For this study, data was collected by means of questionnaires, which was answered by 44 chemistry teachers in 40 different high schools. Results from this study are as follows: As for the perception on the aim and characteristics of chemistry I course, many chemistry teachers have already perceived that the aim of the course was to promote democratic citizens with the knowledge of chemistry. And the most appropriate way of teaching chemistry I course was inquiry-centered teaching such as experiment-practice and inquiry-discussion. However, these perceptions were not reflected when they actually taught students in the classroom. Instead, most of the class was concepts learning and there were a lot of differences in selecting learning contents among chemistry teachers. Furthermore, although chemistry I course was considered a good subject to make students have interest and curiosity in chemistry, it was not appropriate to make students understand the concepts of chemistry. Therefore, learning contents in chemistry I course need to improve. In conclusion, as the goal of 7th national curriculum of chemistry I course was to emphasize inquiry teaching, inquiry based teaching should be practiced in the class. Moreover, sufficient teacher training should be accompanied and alternative additional teaching contents should be developed. Finally teachers' experiences should be reflected in the national curriculum when it is revised.

• Journal of Science Education
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• v.34 no.1
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• pp.23-32
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• 2010

The purpose of this study was to analyze the trend of domestic studies related to science teaching-learning methods. We reviewed articles published according to year, method, subjects and topic. The methods reported commonly in science education books were extracted. Experiment, cooperative learning, and discussion were methods which had been researched widely. Experimental study of them was utilized most. And next content analysis, survey, and case study were utilized much. The most object of experimental study was middle school students. These reviewed papers showed effects which were related to science achievement, attitude, inquiry ability and self-efficacy. As a result of this study we should research to apply and develop science teaching-learning methods variously. We ought to enlarge research direction to analyze context which applies science teaching-learning methods to educational field by qualitative study. We should try to study effects of teaching-learning methods longitudinally and latitudinally.

• Journal of Korean Philosophical Society
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• v.142
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• pp.27-50
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• 2017

When we lose our memories or when our self-identity becomes blurred, we may feel as if our mind has split into multiple minds. If someone makes another 'me' by copying my body and mind, how should two conscious 'I's change their credences? In this article, we present a new thought experiment that can be called the 'Two Adams Problem'. This thought experiment represents a piece of philosophical inquiry that speculates on the nature of self-consciousness information that 'I am awake now'. On Sunday evening, as soon as Adam falls asleep, the philosopher Roro makes another Adam by copying Adam's original body and mind. They sleep separately in another room. Within a minute, Roro throws a fair coin. If the coin lands heads up Roro wakes just one of the Adams up on Monday. If the coin lands tails up Roro wakes both Adams up. On Monday, at least one of the Adams will wake up. To what degree ought they believe that the outcome of the coin toss is heads? We will argue that the correct answer to this question is 1/2.