• Journal of Korean Elementary Science Education
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• v.35 no.2
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• pp.229-242
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• 2016

The purpose of this study was to analyze the elementary teachers' conceptions on the inquiry activity about 'make a fossil model' focusing the 6th, 7th, 2007 revised, and 2009 revised elementary science textbook. This study is intended to find causes of teachers' conceptions and to derive educational implications. We have analyzed questionnaires which were collected from 77 elementary school teachers. It was carried out about comparisons actual fossil with fossil model in each step of the inquiry activity, the lesson goal, the thought for changes of the inquiry activity, the improvement of the inquiry and conception related fossil. Teachers have a general understanding about the contents of the inquiry activity but some of them have partially incorrect understanding. And they emphasize the understanding of the concept on lesson goal. It is necessary to improve inquiry activity reflecting teachers' thinking about the merit and weaknesses. There was not statistically difference in understanding of fossil related concepts according to teachers' career, teaching or training experience. Through this research, there is a need to improve a textbook, a guide book, a teachers' training. So, teachers who have professionalism about science textbook be able to teach students.

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.477-488
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• 2005

Fossil photographs in science and earth science textbooks on the 7th curriculum including those of elementary, middle and high school, are analyzed to estimate the adequacy and scientific significance focusing on the locality and scale. The results show that most of the textbooks have included various types of fossil photographs: 32 in elementary textbooks, 50 in middle school and 109 in high school. However, the presentation of scientific information on each photographs is insufficient. Only $68\%$ of the elementary textbooks designates locality and only $6\%$ includes scales. Among middle and high school textbooks, 40 and $16\%$ of photographs describe locality, and 14 and $18\%$ of photographs exhibit scale, respectively. More scientific and appropriate presentation of fossil photographs, such as locality and scale, is needed to enhance educational effect.

• Environmental and Resource Economics Review
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• v.20 no.2
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• pp.335-356
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• 2011

In this paper, we attempted to suggest a way to evaluate appropriateness and efficiency for the energy consumption structure. For this, based on Markowitz (1952)' mean-variance portfolio model, we constructed an optimal fossil fuel mix. In constructing the optimal mix, we first defined returns on fossil fuels (oil, coal and natural gas) as TOE (Ton of Oil Equivalent) per $1. Then, by using the dynamic latent common factor model, we decomposed the growth rates of the returns on each fossil fuel into two parts : the common part and the idiosyncratic part. Finally, based on the results from the dynamic latent common factor model, we constructed the optimal fossil fuel mix implied by the mean-variance portfolio model. Our results indicate that for the fossil fuel mix to be on the efficient frontier, it is crucial to reduce oil consumption as low as possible. Moreover, our results imply that it is more efficient to increase natural gas consumption rather than coal consumption in reducing oil consumption. These results are in line with the strategies for the future energy consumption structure pursued by Korea and indicate that reduction in oil use can improve overall efficiency in energy consumption.

• Journal of the Korean earth science society
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• v.36 no.2
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• pp.181-189
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• 2015

A large number of fossil conchostraca used in this study were collected from the Amisan Formation distributed in the western part of Chungnam, Korea. These fossils were densely discovered in several horizons of the Amisan Formation, and might have flourished in the fresh water environment of subtropical climate. The fossil conchostraca from the Amisan Formation were classified into four species belonging to three genera as follows: Euestheria kawasakii, E. shimamurai, Sphaerestheria koreanica, and Cyclestherioides rampoensis. Out of four species, the last species was previously described from the Amisan Formation, and the other three species were newly found. Based on the fossil conchostraca, it is inferred that the geological age of the Amisan Formation falls under the Late Triassic Period.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.46-52
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• 1999

Large valves for steam turbines of fossil power plants are exposed to a severe mechanical and thermal loading resulting from steam with high pressure and high temperature. Valve casings are designed to withstand such a loading. During the operation of a plant, temperatures at inner and outer surface of the casings are measured and steam flow is controlled so that the measured difference is lower than the maximum allowable value determined in the design stage. In this paper, a method is presented to calculate the maximum allowable temperature difference at the inner and outer surface of valve casings for steam turbines of fossil power plants. The finite element method is used to analyze distribution of temperature and stresses of a casing under the operating condition. Low cycle fatigue and creep rupture are taken into consideration to determine the maximum allowable temperature difference. The method can be usefully applied in the design stage of the large valves for the steam turbines, contributing to safe and reliable operation of the fossil power plants.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2009.10a
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• pp.599-600
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• 2009

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.140-142
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• 2001

Three single loop fuzzy logic controllers are designed independently for the control of boiler system of fossil-power plant. The control rules and the membership functions of proposed fuzzy logic control system are generated automatically without using plant model. The simulation shows successful results for wide range operation of boiler system of fossil-power plant.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.778-780
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• 1998

The distributied control system consists of PCS(Process Control System), OIS(Operator Interface System), Communication Network and EWS(Engineering Workstation). This parer describes the system structures and the technological trends of domestically developed distributied control system (DCS).

• Korean Journal of Pharmacognosy
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• v.4 no.1
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• pp.9-17
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• 1973

A score and more kinds of molluscan shells have been used as drugs in oriental medicine. The Korean Pharmacopoeia (K.P.) contains a monograph on oyster shell "Ostreae Testa" as an official drug. A huge deposit of the fossil shell Crassostrea gravitesta eoilensis has been recently excavated in the region of Wolsung, Kyong-Sang-Buk-Do. This study was conducted to determine the applicability of the fossil shell as a substiute for Ostreae Testa, K.P. The fossil shell not only met the K.P. requirements, but also exhibited an appropriate antacid activity. Amino acid survivals were also determined quantitatively with amino acid autoanalyzer.

• Herbal Formula Science
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• v.11 no.1
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• pp.171-195
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• 2003

Objectives: This experimental study has been done to compare the Os Draconis composition before and after using processing method. Os Draconis has a quality for calming the liver meridian function and relaxation the mind. Methods: I studied the Os Draconis and processed Os Draconis by vinegar to compare the compositions and its' character. Results: Os Draconis is not a dinosaur's bone fossil but a mammal's bone fossil which has a Calcite mineral, an Apatite mineral, $SiO_2\;Al_2$ O, etc. Os Draconis contains a main ingredients CaO>50.00%. Processed Os Draconis which is heated and soaked in vinegar changes to weak condition Conclusion: Os Draconis is supposed to be a mammal's bone fossil. Some Os Draconis has a radioactive substance like a U, Th so we pay heed to deal with it in a medical clinic.