• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.131-133
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• 2017

We present the latest results from the Mission Program NIRLT (PI: I.Yamamura), the near-infrared spectroscopy of brown dwarfs using the AKARI/IRC grism mode with the spectral resolution of ~ 120. The near-infrared spectra in the wavelength range between 2.5 and $5.0{\mu}m$ are especially important to study the brown dwarf atmospheres because of the presence of major molecular bands, including $CH_4$ at $3.3{\mu}m$, $CO_2$ at $4.2{\mu}m$, CO at $4.6{\mu}m$, and $H_2O$ around $2.7{\mu}m$. We observed 27 sources, and obtained 16 good spectra. Our model fitting reveals deviations between theoretical model and observed spectra in this wavelength range, which may be attributed to the physical condition of the upper atmosphere. The deviations indicate additional heating, which we hypothesize to be due to chromospheric activity. We test this effect by modifying the brown dwarf atmosphere model to artificially increase the temperature of the upper atmosphere, and compare the revised model with observed spectra of early- to mid-L type objects with $H{\alpha}$ emission. We find that the chemical structure of the atmosphere changes dramatically, and the heating model spectra of early-type brown dwarfs can be considerably improved to match the observed spectra. Our result suggests that chromospheric activity is essential to understand early-type brown dwarf atmospheres.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.317-323
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• 2014

Odyssey, one of the NASA's Mars exploration program and SELENE (Kaguya), a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS) for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe) detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA) method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA) method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of $^{40}K$, $^{232}Th$ and $^{238}U$ in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl) and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

• The Korean Journal of Air & Space Law and Policy
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• v.25 no.1
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• pp.97-158
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• 2010

The purpose of this paper is to research on the contents and improvement of national legislations relating to space development in Korea to make the sustainable progress of space development project in Korea. Korea has launched its first satellite KITST-1 in 1992. The National Space Committee has established "The Space Development Promotion Basic Plan" in 2007. The plan addressed the development of total 13 satellites by 2010 and the space launch vehicle by 2020, and the launch of moon exploration spaceship by 2021. Korea has built the space center at Oinarodo, Goheng Province in June 2009. In Korea the first small launch vehicle KSLV-1 was launched at the Naro Space Center in August 2009, and its second launch was made in June 2010. The United Nations has adopted five treaties relating to the development of outer space as follows : The Outer Space Treaty of 1967, the Rescue and Return Agreement of 1968, the Liability Convention of 1972, the Registration Convention of 1974, and the Moon Treaty of 1979. All five treaties has come into force. Korea has ratified the Outer Space Treaty, the Rescue and Return Agreement, the Liability Convention and the Registration Convention excepting the Moon Treaty. Most of development countries have enacted the national legislation relating to the development of our space as follows : The National Aeronautic and Space Act of 1958 and the Commercial Space Act of 1998 in the United States, Outer Space Act of 1986 in England, Establishment Act of National Space Center of 1961 in France, Canadian Space Agency Act of 1990 in Canada, Space Basic Act of 2008 in Japan, and Law on Space Activity of 1993 in Russia. There are currently three national legislations relating to space development in Korea as follows : Aerospace Industry Development Promotion Act of 1987, Outer Space Development Promotion Act of 2005, Outer Space Damage Compensation Act of 2008. The Ministry of Knowledge Economy of Korea has announced the Full Amendment Draft of Aerospace Industry Development Promotion Act in December 2009, and it's main contents are as follows : (1) Changing the title of Act into Aerospace Industry Promotion Act, (2) Newly regulating the definition of air flight test place, etc., (3) Establishment of aerospace industry basic plan, establishment of aerospace industry committee, (4) Project for promoting aerospace industry, (5) Exploration development, international joint development, (6) Cooperative research development, (7) Mutual benefit project, (8) Project for furthering basis of aerospace industry, (9) Activating cluster of aerospace industry, (10) Designation of air flight test place, etc., (11) Abolishing the designation and assistance of specific enterprise, (12) Abolishing the inspection of performance and quality. The Outer Space Development Promotion Act should be revised with regard to the following matters : (1) Overlapping problem in legal system between the Outer Space Development Promotion Act and the Aerospace industry Development promotion Act, (2) Distribution and adjustment problem of the national research development budget for space development between National Space Committee and National Science Technology Committee, (3) Consideration and preservation of environment in space development, (4) Taking the legal action and maintaining the legal system for policy and regulation relating to space development. The Outer Space Damage Compensation Act should be revised with regard to the following matters : (1) Definition of space damage and indirect damage, (2) Currency unit of limit of compensation liability, (3) Joint liability and compensation claim right of launching person of space object, (4) Establishment of Space Damage Compensation Council. In Korea, it will be possible to make a space tourism in 2013, and it is planned to introduce and operate a manned spaceship in 2013. Therefore, it is necessary to develop the policy relating to the promotion of commercial space transportation industry. Also it is necessary to make the proper maintenance of the current Aviation Law and space development-related laws and regulations for the promotion of space transportation industry in Korea.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.173-179
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• 2017

The purpose of this study is to theoretically explore the pedagogical meaning of Flipped Learning (FL) through the lens of Bakhtinnian Dialogism. Flipped learning has emerged based on technological development, which enables educators to reorganize educational space and time. In the new converged time and space, teachers changed the activities in and out of classes, flipped lectures with students' activity, and redefined the role of teachers and students. These dialogical characteristics of FL results in several educational consequences: first, underscoring educational dialogue, second, extending the participation in the dialogical chain, third, deconstructing the existing authority of knowledge, and escalating the self-directedness of learners.

• Korean Institute of Interior Design Journal
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• v.22 no.1
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• pp.164-173
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• 2013

This study aims to analyze the aesthetic thought and expression tendency appeared in contemporary architecture by looking at today's architectural art based on the concept of the uncanny that Sigmund Freud contended as an aesthetic principle, of the aesthetic concepts tossed around to define the contemporary times in the aesthetics field and discuss the architectural analysis possibility of the concept of the uncanny. The generation structure of the uncanny that generates experiences of fear and surprise is classified into dual structure, trauma, threatening structure, and repetition compulsion. This is the principle that evokes a sense of experiencing subject, incorporates sensibility, and vitalizes internal process. This is also the methodology to organize and structure the concept of the uncanny. When seen from the four factors drawn from the concept of the uncanny and aesthetic expressions, the uncanny expression characteristics of contemporary architecture includes isolation, subversion, trace, absence, oblique line, flotation, concealment, and disturbance. Isolation and subversion refers to producing the space of the pressure of tension and relaxation caused by repression and relief from repression and eliciting the maximum expansion of the sense of space through spatial change. Trace and absence indicates being able to elicit more intense emotions from the experiencing subject by applying the images of alienation and absence in the way to reproduce historical trauma. This happens by implementing the potential value of physical activity. Oblique line and flotation means visual impulse. This happens in the way to visualize uneasy points. This causes uncanny by threatening the survival. Finally, concealment and disturbance refers to creating unpredictable space. The concept of masquerade and maze space composition are applied in the way to activate spatial perception, including space exploration and unintended subject's forced selection. As stated above, the uncanny expression characteristics shown in contemporary architecture can be presented as indicators that are available to analyze the undecided and diversified contemporary architecture aesthetically. In this respect, this study has great significance.

• Korean Institute of Interior Design Journal
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• v.22 no.6
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• pp.108-118
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• 2013

This study has analyzed the process of space information perceived and recognized through the estimation of observation frequency and number according to the time range of observation data acquired from observation experiment with the object of hospital lobby. The followings are the results analyzed at this study. First, the continual observation of 3 and 6 times was attentive and conscious for probing to find an object rather than for acquiring exact information and that of 9 times could be regarded as the time for acquiring visual appreciation. However, the repetitive occurrence of high and low frequencies can be thought of repetitive acts for visual appreciation. Second, the continual observation of 3 and 6 times had the highest observation frequency of II, while that of 9 times had the highest observation frequency of III. In case of 3 and 6 times, the observation frequency had the tendency to become a little higher after being low since V, and in case of 9 times it had the repetition of becoming low and high and from IX it characteristically got higher. This feature can be thought to be the process that the subject repeats the fixation and movement of observation at a visual activity for perception and recognition. In the process of first observation, the observation frequency was the highest after 20 seconds or so, but since then, it gets lower and repeatedly gets higher and lower as time passes. After 90 seconds, the frequency showed the tendency of getting higher continuously. Third, the examination of changing features of frequency may show the characteristics of exploration for and attention to space but if the observation frequency is not associated with observation times for analysis there will a limitation that the features of observation frequency cannot be clarified. Accordingly, the simultaneous analysis of both is very effective for estimating the observation characteristics seen at the processes of perception and recognition. Fourth, the general analysis of the both revealed: with the progress of observation time the discontinuous space exploration decreased, and as the observation time got longer the fixed attention to a specific spot increased. Fifth, in order to estimate the observation characteristics by the change of time range the observation frequency and times by trend line was analyzed, which approach seems to be an appropriate technique that can comprehensively show the overall flow of time series data.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.3-13
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• 2008

The year 2007 marked two important anniversaries for space. The Soviet Union launched Sputnik 50 years ago on October 4. 1957. The 40th anniversary of the United Nations treaty on outer space was also marked in 2007. 2008 and 2007 were full of dramatic events of space activity as well : Success of Japan's first large lunar explorer 'KAGUYA'(SELENE) and China's 'Chang'e 1', launch of ISS laboratory module, 'Colombus' and 'Kibo', test of China's ASAT, and success of Korea's first astronaut program and so on. International government space budgets reached $78.3 billion in 2007, a strong growth rate of 36% over 2006, and the recently released Global Exploration Strategy, The Framework for Coordination is a set of guidelines for international cooperation among 14 of the world's space agencies. Worldwide space industry revenue grew by 20% over 2005, $106.1 billion in 2006 and $173.9 billion expected in 2007. This paper discusses the issues related to the Earth observation R&D trend and market in detail. Korea's 2008 government space spending is \316.4 billion, 2007 space industry revenue was $106 million. Several research projects are now underway and STSAT 2 will be launched by KSLV-1 at the Naro Space Center within this year.

• The Mathematical Education
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• v.34 no.1
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• pp.17-63
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• 1995

The exploration of Mathematics-learningmodel on the basis of Cognitive development The purpose of this paper is to sequenctialize Mathematics-learning contents, and to explore teaching-learning model for mathematics, with on the basis of the theory of cognitive development and the period of condservation formation for children. The Specific topics are as follows: (1) Systemizing those theories of cognitive development which are related to Mathematics - learning for children. (2) Organizing a sequence of Mathematics - learning, on the basis of experimental research for the period of conservation formation for children. (3) Comparing the effects of 4 types of teaching - learning model, on the basis of inference activity and operational learning principle. $\circled1$ Induction-operation(IO) $\circled2$ Induction-explanation(IE) $\circled3$ Deduction-operation(DO) $\circled4$ Deduction-explanation(DE) The results of the subjects are as follows: (1) Cognitive development theory and Mathe-matics education. $\circled1$ Congnitive development can be achieved by constant space and Mathematics know-ledge is obtained by the interaction of experience and reason. $\circled2$ The stages of congnitive development for children form a hierarchical system, its function has a continuity and acts orderly. Therefore we need to apply cognitive development for children to teach mathematics systematically and orderly. (2) Sequence of mathematical concepts. $\circled1$ The learning effect of mathematical concepts occurs when this coincides with the period of conservation formation for children. $\circled2$ Mathematics Curriculum of Elementary Schools in Korea matches with the experimental research about the period of Piaget's conservation formation. (3) Exploration of a teaching-learning model for mathematics. $\circled1$ Mathematics learning is to be centered on learning by experience such as observation, operation, experiment and actual measurement. $\circled2$ Mathematical learning has better results in from inductional inference rather than deductional inference, and from operational inference rather than explanatory inference.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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• pp.309-316
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• 2013

Since the solar activity, one of the factors influencing on lunar communication systems, is to reach its maximum occurring at 11-year solar cycle in autumn 2013, the solar burst frequency and strength are expected to increase. The solar burst has an effect on earth magnetosphere and causes malfunction, loss of communication, and breakdown of various types of satellites and probes. These problems give rise to huge economic and physical loss. Therefore, we should analyze the effect of solar burst on lunar communications and minimize the expected loss. In this paper, we perform the analysis of the link model and link performance between a land station and a lunar orbiter under the solar burst for orbiter's survivability and stable communication channel operations.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.287-291
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• 2017

We present the results of our mid-infrared (MIR) observations of distant clusters of galaxies with AKARI. The wide-field of view of IRC/AKARI ($10^{\prime}{\times}10^{\prime}$) is ideally suited for studying dust-obscured star-formation (SF) activity of galaxies along the cosmic web in the distant universe. We performed a deep and wide-field $15{\mu}m$ (rest-frame ${\approx}8{\mu}m$) imaging observation of the RXJ1716+6708 cluster (z = 0.81) with IRC. We find that $15{\mu}m$-detected cluster member galaxies (with total infrared luminosities of $L_{IR}{\geq}10^{11}L_{\odot}$) are most preferentially located in the cluster outskirt regions, whilst such IR-luminous galaxies avoid the cluster centre. Our $H{\alpha}$ follow-up study of this field confirmed that a significant fraction of $15{\mu}m$-detected cluster galaxies are heavily obscured by dust (with $AH{\alpha}$>3 mag in extreme cases). The environment of such dusty star-burst galaxies coincides with the place where we see a sharp "break" of the colour-density relation, suggesting an important link between dust-obscured SF activity and environmental quenching. We also report the discovery of a new cluster candidate around a radio galaxy at z = 1.52 (4C 65.22), where we obtained one of the deepest IRC imaging datasets with all the nine filters at $2-24{\mu}m$. This field will provide us with the final, excellent laboratory for studying the dust-enshrouded SF activity in galaxies along the cosmic web at the critical epoch of cluster galaxy evolution with AKARI.