• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.217-227
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• 2009

Heavy minerals in the marine sand near Haeju bay, Hwanghae-do, North Korea were separated using the gravity and the magnetic separators. And their mineralogical study was carried out. Ilmenite, magnetite, hematite, zircon and monazite were observed as the valuable minerals, and quartz, orthoclase, muscovite, hornblende and garnet existed as gangue minerals. In the result of quantitative analysis with SIROQUANT program, the contents of the valuable minerals separated with the 2nd gravity separation (the shaking table separation), the 1st magnetic separation (rare earth magnetic separation) and the 2nd magnetic separation (the Eddy current magnetic separation) were increased into 4%, 10% and 76~89% (under the condition of 7000 G and 10000 G in magnetic strength), respectively. The contents of ilmenite, monazite and zircon recalculated from the chemical composition differed from the results of the quantitative analyses by SIROQUANT program, but the entire tendency bears some analogy with it. Under the conditions of 7000 G and 10000 G in 2nd magnetic separation the contents of ilmenites were concentrated with 53% and 66%, respectively. The content of monazite was 1.2% in the magnetic fractions of the 1st magnetic separation. The content of zircon was shown 1.4% under the condition of 10000 G in the 2nd magnetic separation, and was displayed 9% in +50 mesh of non-magnetic fraction of 1st magnetic separation, especially.

• Journal of the Korean Chemical Society
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• v.62 no.2
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• pp.148-158
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• 2018

In this study, we investigated the characteristics of planning lessons using analogies by pre-service science teachers. Eight pre-service teachers at a college of education in Seoul participated in this study. After the workshop of instructional analogies in science education, they planned lessons using analogies. We also conducted semi-structured interviews. For the analyses, we used a revised framework from a previous work which characterized the dimensions of teaching through analogies. The analyses of the results revealed that most pre-service teachers planned to use analogies in beginning or developing lesson and to present analogs before target concepts. The degree of activity allowed for students was not high. Many did not recognize the necessity of assessment and did not include assessment in planning lessons. They planned clarified mapping strategies which are teacher-centered and also not to cover unshared attributes and multiple analogies, because they thought that students could misunderstand mapping and unshared attributes could make students confused. Most planned to use figures, pictures, and videos to help students understand analogies that they presented. Educational implications of these findings are discussed.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.151-167
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• 2015

Korean movie maintain their market share from the highest 59.7% to the lowest 42.1% during the last ten years in Korea. However, with the multiplex and wide release strategy, the monopolies of four major distribution companies and three multiplex chain, the polarization of Korean movie's Box Office performance is deepening. With Gini-Index, concentration of film admission has been deepened in intensity from 0.53 in 2004 to 0.85 in 2014. Using Thomas Piketty's method, Movie attendance proportion of Highest 10% of the box office ranking for 2014 sharply increased to 71.2% from 30.28% in 2004 and the lowest 50% of box office ranking dropped from 11.03% in 2004 to 0.08% in 2014. Concentrations of the number of Screen, Screening, the seating Capacity have the same analogy with the polarization of film admission. However, concentration of seating share has maintained a modest increase from 0.22 in 2004 to 0.38 in 2014. This analysis shows that polarization of Korean movie box office performance is not the sole result of Natural selection of market but the result of the monopolies of distribution companies and Multiplex chains.

• Journal of Korean Elementary Science Education
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• v.25 no.4
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• pp.383-395
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• 2006

School science is often criticized as being too remote from both learners' interests and needs and as maintaining scientist-oriented approaches rather than humanistic ones. Although science is mainly taught on the basis of textbooks inside classrooms, the learning of science can not be confined to the boundaries of curriculum and school. Firstly, this paper briefly reviews and characterizes the historical development of science education with a series of analogies, and then suggests a new analogy, a so-called 'Hearts-On' approach to science education which emphasizes the humanistic aspects and the contextual dimension of science education. Secondly, it critically examines how much traditional school science teaching, particularly in physics, is limited in terms of the context of learning (i.e. textbook, laboratory, classroom, local, and global) as well as in terms of the context of the contents (i.e. physical, personal, social, and global). Thirdly, some recent attempts initiated by the author and colleagues are explained as examples of the Hearts-On approach to science education. In particular, a series of community-based science programs led by SNU and the development of a series of books on 'Contextual Physics'(i.e. Body Physics, Wearing Physics, Dining Table Physics, and Sports Physics) are outlined. Finally, the idea of scientific humanism is explored in relation to the context-rich approaches in science education. It is hoped that this paper helps us to reconsider how we can expand the world of science education beyond the boundaries of the curriculum and school and into a more humanistic one.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.37-61
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• 2013

In modern international law, the absence of legal definition regarding drone(Unmanned Aerial Vehicle) has made legal scholars work on an typical analogy between aircraft codified in the international document and drone. The wording of the Convention on International Civil Aviation is limited to two categories of aircraft, such as civil aircraft and state aircraft, whereas military aircraft is not legally defined. As such it is, the current practices of the State regarding the drone flight over foreign territory have proven a hypothese that drone is being deemed as military aircraft. Principal usage of drone lies in reconnaissance and surveillance mission as well as so-called targeted killing, which is prohibited if the killing is treacherous. Claimed war against terrorism, however, is providing a legal rationale that targeted killing is not treacherous, and that the targeted person is not civilian but combatant. In such context, armed attack of drone is deemed legal and justified. Consequently, such attack is legal in the general context of the war. The rules that govern targeting do not turn on the type of weapon system used, and there is no prohibition under the laws of war on the use of technologically advanced weapons systems in armed conflict so long as they are employed in conformity with applicable laws of war. Drones may present interesting new challenges because of their sophistication and the technological advantage they convey to their operators.

• 대한공업교육학회지
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• v.37 no.2
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• pp.99-125
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• 2012

The objectives of this study was to apprehend the displaying components by comparing and analyzing the ten types of construction textbooks used in Technical high schools by elaboration theory by Ferigeluth, and to supply preliminary data for the following revising textbooks. To achieve them, first, comparable units were excerpted by analyzing between the national textbooks of 7th curriculum and the new revised curriculum used in Technical high schools. Second, each five types of 7th and new curriculum textbooks were compared and analyzed by seven requisites in the Elaboration theory by Reigeluth. As the results of the study, first, elaborating process like conceptual, procedural, and theoretical elaboration has been applied to the different subjects according to their properties. Second, cognitive strategy activator among the seven strategies was widely used. Whereas, analogy was not applied to all the ten types of the text books. In addition, Learning prerequisite sequence was presented with only simple picture and explanation, and it was inadequately used in practice. Third, summary was more used in 7th curriculum text than the new revised text. Fourth, six strategy components were widely used to all texts except construction and materials in the five types of texts. Lastly synthesis of theory and practice was more used than summary in theory subjects and learner control was more used in the subject of the synthesis of theory and practice.

• Bulletin of the Society of Naval Architects of Korea
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• v.22 no.1
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• pp.45-53
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• 1985

For the analysis of vertical vibrations of a ship's hull, the Timoshenko beam analogy is accepted up to seven or eight-node modes provided that the system parameters are properly calculated. As to the shear coefficient, it has been a common practice to apply the strain energy method or the projected area method. The theoretical objection to the former is that it ignores lateral contraction due to Poisson's ratio, and the latter is of extreme simplifications. Recently, Cowper's and Stephen's shear coefficient formulas have drawn ship vibration analysts' attentions because these formulas, derivation of which are based on an integrations of the equations of three-dimensional elasticity, take Poisson's ratio into account. Providing computer programs for calculation of the shear coefficient of ship sections modeled as thin-walked multicell sections by each of the forementioned methods, the authors calculated natural vibration characteristics of a bulk carrier and of a container ship by the transfer matrix method using shear coefficients obtained by each of the methods, and discussed the results in comparision. The major conclusions resulted from this investigation are as follows: (1) The shear coefficients taking account of the effects of Poisson's ratio, Cowper's $K_c$ and Stephen's $K_s$, result in higher values of about 10% in maximum as compared with the shear coefficient $K_o$ based on the conventional strain energy methods; (a) $K_c/K_o{\cong}1.05\;and\;K_s/K_o{\cong}1.10$ for ships having single skin side-shell such as a bulk carrier. (b) $K_c/K_o{\cong}1.02\;and\;K_s/K_o{\cong}1.05$ for ships having longitudinally through bulkheads and/or double side-shells in the portion of the cargo hod such as a container carrier. (2) The distributions of the effective shear area along the ship's hull based on each of $K_o,\;K_c\;and\;K_s$ are similar each another except the both end portions. (3) Natural frequencies and mode shapes of the hull based on each of $K_c\;and\;K_s$ are of small differences as compared each other. (4) In cases of using $K_c\;or\;K_s$ in ship vibration analysis, it is also desirable to have the bending rigidity be corrected according to the effective breadth concept. And then, natural frequencies and mode shapes calculated with the bending rigidity corrected in the above and with each of $K_o,\;K_c\;and\;K_s$ result in small differences as compared each another. (5) Referring to those mentioned in the above (3) and (4) and to the full-scale experimental results reported by Asmussen et al.[17], and considering laboursome to prepare the computer input data, the following suggestions can safely be made; (a) Use of $K_o$ in ship vibration analysis is appropriate in practical senses. (b) Use of $K_c$ is appropriate even for detailed vibration analysis of a ship's hull. (6) The effective shear area based on the projected area method is acceptable for the two-node mode.

• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.41-54
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• 1991

This paper aimed to analyse dose sensitivity to the controllable parameters of indoor radon $(^{222}Rn)$ and its decay products (Rn-D) by applying the input~output linear system theory. Physical behaviors of $^{222}Rn\;&\;Rn-D$ were analyzed in terms of $(^{222}Rn)$ gas -generation, -migation and -infiltration to indoor environments, and the performance output-function, i. e. mean dose equivalent to Tracho-Bronchial (TB) lung region, was assessed to the following extented ranges of the controllable paramenters; a) the ventilation rate $constant({\lambda}_v)\;:\;0{\sim}50[h^{-l}].\;b)$ the attachment rate $constant({\lambda}_a)\;:\;0{\sim}500[h^{-l}].\;c)$ the unattached-deposition rate constant (${\lambda}^u_d)\;:\;0-50[h-l]$. A linear input-output model was reconstructed from the original models in literatures, as follows, which was modified into the matrices consisting of 111 nodal equations; a) indoor $^{222}Rn\;&\;Rn-D$ Behaviour; Jacobi-Porstendoerfer-Bruno model.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.45-57
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• 2002

In this paper, the results gained by applying many impingement models to the cylinder and flat plate were analyzed in comparison with the experimental data to study a spray/wall interaction phenomena. To begin with, the behavior of spray injected normal to the wall was analysed using three different impingement models ; Naber and Reitz model(NR model), Watkins and Wang model(WW model) and Park and Watkins model(PW model) in the present calculation. The results obtained from these models were compared with experimental data of Katsura et. al. The results indicated that PW model was in better agreement with experimental data than the NR and WW model. Also f3r spray injected at 30DEG , the result of three models were compared with experimental data of Fujimoto et. al. The results showed that m model overpredicted the penetration in the radial direction because this model was based on the inviscid jet analogy. WW model did not predicted the radius and height of the wall spray effectively. It might be thought that this discrepancy was due to the lack of consideration of spray film velocity occurred at impingement site. The result of PW model agrees with the experimental data as time goes on. In particular, a height of the spray droplets was predicted more closely to the experimental data than the other two models. The results of PW model in which the spray droplets were distributed densely around the edge of droplet distribution shaped in a circle had an agreement with the experimental data of Fujimoto et. al. Therefore, it was concluded that PW model performed better than M and WW model for prediction of spray behavior. The numerical calculation using PW model performed to the cylinder similar to the real shape of DI engine. The results showed that vortex strength near the wall in the cylinder was stronger than that in the case of flat plate. Contrary to the flat plat, an existence of the side wall in the cylinder caused the tangential velocity component to be reduced and the normal velocity component to be increased. The flow tends to rotate to the inside of cylinder going upward to the right side wall of cylinder gradually as time passes. Also, the results showed that as the spray angle increases, the gas velocity distribution and the tumble flow seemed to be formed widely.

• Journal of Technologic Dentistry
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• v.34 no.3
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• pp.273-281
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• 2012

Purpose: This study conducted a survey on the elderly of 65 years and over with physical debilities and ones capable of living at home residing in Jeju Special Self-Government Province to compare and analyze demo-sociological characteristics and factors influencing on oral health related living quality. And also this study intended to provide basic data for developing effective public medical policies and health promotion programs to increase oral health related living quality of the elder. Methods: The elderly of 65 years and over living in Jeju Special Self-Government Province were interviewed individually from 7 February 2011 to 18 April and interview results of a total of 220 subjects were analysed for this study. Results: Current status of the elderly including ones with & without physical debilities influenced functional limitation and behavioral aspects of GOHAI criteria used in this study. The elderly with physical debilities experienced less limitation in food chewing and swallowing, and pronunciation than ones capable of living at home. On the analogy of the previous study(by Park, N. G., 2010) in which oral health related quality and satisfaction of life of the elderly with physical debilities were different due to their physical, circumstantial and psychological limitations, the former's oral health conditions are worse than the ones capable of living at home and because of medical care accessability limitation they suffer from deteriorated oral condition. By the comparison of factors influencing on the living quality relating to the oral health of the elderly with physical debilities and ones capable of living at home, 2 factors, age and living area, were meaningful factors commonly influencing on the oral health related living qualities of both. The elderly of 75 years and over were more affected by psychological and behavioral aspects of oral health related living quality than the ones of 65-74 years, and the ones living in country suffered from functional limitations, pains and discomfort more than ones in city. Additionally, being different from the elderly capable of living at home, the ones with physical debilities were influenced by the factors of average monthly income and medical security type. Conclusion: Improvement of programs and systems to increase oral health related quality of life needs to be carried out preferentially for the elderly of 75 years and over, and dwelling in country. Also this study suggests that the policy of paying the denture insurance allowance in 2012 need effective planning considering the elderly's current status, age, living area, medical security type.