• Journal of the Korean Society of Earth Science Education
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• v.13 no.3
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• pp.305-316
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• 2020

This study aimed to analyze the conception of an extra-solar planet perceived by university students. To conduct this, we developed an extra-solar planet education program and questionnaires which help to figure out changes between before and after the program, and then applied them to the targeted students. The results of the study are as follows. First, as to the conception of an extra-solar planet, participants understood it merely as a planet outside the solar system before they got training. However, they expanded it to the one revolving around a star that appears outside the solar system based on keywords after the training. Second, they gave brief responses regarding exploration strategies (e.g., observing the extra-solar planet by using the Doppler effect, dietary phenomenon, and gravitational lens) based on indirect experiences they encountered in the media. The responses indicated their lack of concept of the extra-solar planet exploration methods. However, their recognition of the extra-solar planet observation became concrete while students learned about the exploration of the extra-solar planet. Third, they were expanding the importance of the exoplanet observation simply beyond the discovery of extraterrestrial life to the creative process and research methods, including the solar system and the development of humanity. Fourth, they recognized that exoplanet education is necessary for curriculum as it will be able to bring about students' interest and curiosity as well as scientific knowledge if contents related to the extra-solar planet appear in the earth science curriculum.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.10
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• pp.836-843
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• 2017

In lunar exploration, the necessity of utilizing rover is verified by the examples of the Soviet Union and China and the similar Mars missions of the United States. In order to achieve the successful management of a lunar rover, a high precision navigation technique is required, and accordingly, high precision initial alignment is essential. Even though it is general to perform initial alignment in a steady state, a multiposition alignment technique is applied when high performance is needed. On the lunar surface, however, the performance of initial alignment decreases from that on Earth, and it cannot be improved by applying multiposition alignment method owing to certain constraints of lunar environment. In this paper, a sun sensor aided multiposition alignment technique is proposed. The measurement model for a sun vector is established, and its observability analysis is performed. The performance of the proposed algorithm is verified through computer simulations, and the results show the estimation performance is improved dramatically.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3571-3577
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• 2010

The estimated location coordinator exploration scheme and the E&E(Equivalent distance rate & Estimated location coordinator exploration) compensation algorithm for localization is proposed, and the performance of the E&E is analyzed in this paper. The proposed scheme is adapted to the AEDR(Algorithm for localization using the concept of Equivalent Distance Rate). From several experiments, it is confirmed that the performance of the localization compensation in SDS-TWR is improved from 0.60m to 0.34m in four experimental scenarios, and the performance of the localization compensation ratio of the E&E is also better than that of the AEDR as a level of maximum 15%. It can be thought that the proposed localization compensation algorithm E&E can be sufficiently applicable to various localization applications because the performance of the localization error rate of the E&E is measured as less than 1m in 99% of the total performance experiments.

• Korean Institute of Interior Design Journal
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• v.25 no.5
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• pp.71-81
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• 2016

This research has been carried out with the objects of sporting goods shops to find out what structure of those shops raises more interest from customers. The tracking eyes on the objects which are the same but seen to have different structures has revealed the followings. Customers' visual appreciation of Reverse left/right Images (11.1) was found to be higher than that of Original Images (10.6). Furthermore, the reverse left/right image of the space also was found to attract more interest from customers, which led them to have longer observation. The below is about the interpretation of the spatial exploration by observation time and the appreciation of its visual content in line with the experiment objects of selling spaces. The longer the space was observed, (1)the higher the expansive searching of space was, (2)the more spots were observed as if they did not know what to see after they first observed at early hours, (3)later (in the time range of 64~73 seconds) they came to look at the spots in which they got interested, (4)and then again they suddenly got lost what to see. When the change of observation characteristics by time range is reviewed, it can be seen that the searching of original images is changed from Divergent Feature to Convergent Feature when the observation time increases from the early stage of observation to the later. On the contrary, the reverse left/right images were found to have the opposite searching features, that is, from convergent exploration to divergent exploration. These findings show that the reverse left/right images of the sporting goods shops, which were the experiment objects, have more factors attracting customers' attention and interest and that it is the very shop-structure which makes customers have better visual appreciation of those shops.

• Geomechanics and Engineering
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• v.14 no.5
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• pp.467-477
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• 2018

Estimation of hydraulic parameters is a critical step during design of foundation dewatering works. When many piles are installed in an aquifer, estimation of the hydraulic conductivity should consider the blocking of groundwater seepage by the piles. Based on field observations during a dewatering project in Shanghai, hydraulic conductivities are back-calculated using a numerical model considering the actual position of each pile. However, it is difficult to apply the aforementioned model directly in field due to requirement to input each pile geometry into the model. To develop a simple numerical model and find the optimal hydraulic conductivity, three scenarios are examined, in which the soil mass containing the piles is considered to be a uniform porous media. In these three scenarios, different sub-regions with different hydraulic conductivities, based on either automatic inverted calculation, or on effective medium theory (EMT), are established. The results indicate that the error, in the case which determines the hydraulic conductivity based on EMT, is less than that determined in the automatic inversion case. With the application of EMT, only the hydraulic conductivity of the soil outside the pit should be inverted. The soil inside the pit with its piles is divided into sub-regions with different hydraulic conductivities, and the hydraulic conductivity is calculated according to the volume ratio of the piles. Thus, the use of EMT in numerical modelling makes it easier to consider the effect of piles installed in an aquifer.

• Geophysics and Geophysical Exploration
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• v.10 no.1
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• pp.44-49
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• 2007

It is difficult to obtain high-resolution images by 3D gravity inversion, because the problem is extremely underdetermined - there are too many model parameters. In order to reduce the number of model parameters we propose a 3D gravity inversion scheme utilising Euler deconvolution as a priori information. The essential point of this scheme is the reduction of the nonuniqueness of solutions by restricting the inversion space with the help of Euler deconvolution. We carry out a systematic exploration of the growing body process, but only in the restricted space within a certain radius of the Euler solutions. We have tested our method with synthetic gravity data, and also applied it to a real dataset, to delineate underground cavities in a limestone area. We found that we obtained a more reasonable subsurface density image by means of this combination between the Euler solution and the inversion process.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.34.2-34.2
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• 2017

A small wide-field imaging telescope is a powerful instrument to survey the Universe: wide-field image can monitor the variability of many sources at a time, e.g. young stellar objects and active galactic nuclei, and it can be an effective way to locate transient sources without precise positional information such as gravitational wave sources or some gamma-ray bursts. In February 2017, we installed a 0.25 m f/3.6 telescope on the McDonald 0.8 m telescope as a piggyback system. With a $4k{\times}4k$ CCD camera, the telescope has a $2.35{\times}2.35deg$ field-of-view. Currently, it is equipped with Johnson UBVRI filters and 3 narrow-band filters: $H{\alpha}$, OIII and SII. We will present the installation process, and the telescope performance such as detection limit and image quality based on the data from commissioning observations. We will also discuss possible scientific projects with this system.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.613-618
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• 2012

ICT education guidelines revised in 2005 reinforce computer science elements such as algorithm, data structure, and programming covering all schools. And Ministry of Education emphasizes STEAM education. Most important is that "How instruct them". This means necessity of contents. So this paper suggests learning method of Stack and Queue using LEGO MINDSTORMS NXT. The main purpose is that how stack and queue are used, when robot explore realistic maze. Teaching and learning strategies are algorithm, flowchart, and NXT-G programming. Simple maze has path in left or right, but complex maze has three-way intersection. These are developed by authors. Master robot explores maze and push stack, and then return to entrance using stack. Master robot explores maze and transmits path to slave's queue. And then slave robot drives without exploration. Students can naturally learn principles and applications of them. Through these studies, it can improves ability of logical and creative thinking. Furthermore it can apply to ICT and STEAM education.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.2
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• pp.207-223
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• 2008

The launching of the Taepo-dong 1 on 31 August 1998 by the North Korea was the first case where the diplomatic protests was made against the flight, the purpose of which, the launching State claimed, consisted in space exploration and use. It is the principle regarding the freedom of space exploration and use, as included in the international treaty, that is relevant in applying the various rules and in defining the legal status of the flight. Its legal status, however, was not actually taken into account, as political negotiations leading to the test moratorium has been successful until present day in freezing the political crisis. This implies that the rules of the law lack the validity and logic sufficient in dictating the conduct of the States. This case shows that, in effect, it is not the rule but the politics that is to govern the status of the flight.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.413-415
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• 2015

How galaxy evolution differs in different environments is one of the intriguing questions in the study of structure formation. While galaxy properties are clearly distinguished in different environments in the local universe, it is still an open issue what causes this environmental dependence of various galaxy properties. To address this question, in this work, we investigate the build-up of passive galaxies over a wide redshift range, from z ~ 2 to z ~ 0.5, focusing on its dependence on galaxy environment. In the UKIDSS/Ultra Deep Survey (UDS) field, we identify high-redshift galaxy cluster candidates within this redshift range. Then, using deep optical and near-infrared data from Subaru and UKIRT available in this field, we analyze and compare the stellar population properties of galaxies in the clusters and in the field. Our results show that the environmental effect on galaxy star-formation properties is a strong function of redshift as well as stellar mass - in the sense that (1) the effect becomes significant at small redshift, and (2) it is stronger for low-mass ($M_{\ast}<10^{10}M_{\odot}$) galaxies. We have also found that galaxy stellar mass plays a more significant role in determining their star-formation property - i.e., whether they are forming stars actively or not - than their environment throughout the redshift range.