• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.579-585
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• 2019

Increasing the detection probability of underwater targets necessitates securing the towing stability of the active towed SONAR. In this paper, to confirm the effects of tail wing fin on towing attitude and towing stability, two scale model experiments and one sea trials were conducted and the results were analyzed. The scale model tests measured the towing behavior of each of the tail fin shapes according to towing speed in a towing tank. The shape of the tail fin used in the scale model test was tested with an I-type tail fine and four Y-type tail fins, totaling five tail fins of the two kinds. The first scale model test confirmed that the Y-type tail fin was superior to the I-type tail fin in towing attitude and towing stability. The second scale model test confirmed the characteristics of the vertical tail fin height increase and the lower horizontal tail fin inclination angle application shape based on the Y-type tail fin. The shape of the application of the lower horizontal tail fin inclination angle showed the best performance. In order to verify the results of the scale model test, a full size model was constructed, sea trials were performed, and the towing attitude was measured. The results were similar to those of the scale model test.

• Korean Journal of Heritage: History & Science
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• v.50 no.3
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• pp.30-43
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• 2017

The purpose of this study is to improve the usefulness of photogrammetry in the field of cultural heritage recording concentrated on laser scanning. Two measurement methods(laser scanning, photogrammetry) were compared in terms of accuracy and reality for the Rock-carved Standing Buddha in Singyeong-ri, Hongseong. With regard to accuracy, the distances of major points by both shape information and between the two shape information were compared. Only a deviation of about 1mm was found in the distance measurement of the major points by both shape information. In particular, the average distance between two shape information identified through aligning was only about 0.01mm. Also, the absolute deviation within about 2mm accounted for 70% of the total, and the absolute deviation within about 3.5mm was found to be 95.4% of the total. These values showed very high similarity between laser scanning and photogrammetry-based shape information. In respect of reality, the carved depth, texture, and patterns were compared. As a result of comparing four cross-sectional shapes, only slight differences were found in the shape information of both measurement techniques and similar shapes were identified. The overall texture of both shape information was also similar. However, the detailed shape based on the photogrammetry with decimation is realized with a smoother texture than the original and laser scanning. In particular, Photogrammetry also realistically expressed the various ornaments carved in the Rock-carved Buddha and the patterns with shallow depths were comparatively detailed.

• Journal of the Korean Society of Earth Science Education
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• v.12 no.2
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• pp.141-150
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• 2019

The purpose of this study is to investigate the effect of the pre-service teacher's maker project learning on self -directed learning ability and creative personality. This study established an eight-week period of experimental treatment from March to April 2019, and the students who participated in the study formed a research group of 75 students in three of their advanced classes who are attending the second semester of B University of Education and taking courses in 'Teaching Research 1'. The experimental treatment of research groups was conducted by the process of producing creative outputs through training of manufacturers. The experimental group of the study group was a process of producing creative output through maker education. The theme was set up to create creative output by group, worked with the main tool, 3D pen, and utilized the recycling material. When the creative output is completed, it is announced by presenting the actual product in each group. The results of the study are as follows. First, project learning by pre-service teachers had an effect on self-directed learning ability. Second, project learning by pre-service teachers had an effect on creative personality. Third, pre-service teachers was interested in learning about the project and responded positively to the students' perception.

• Journal of The Korean Association For Science Education
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• v.39 no.2
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• pp.233-248
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• 2019

This study shows that the Argovian Cantonal School in Aarau, Switzerland, which Albert Einstein attended from 1895 to 1896, had been closely related to the ideological education controversy in German Gymnasium throughout the 19th century. Due to this controversy, Einstein hardly received a formal science education in Bavaria. Despite the lack of formal education in Germany, he had a habit of self-studying from an early age and continued with this practice all through his life. He had a hard time at the authoritarian school in Munich, but at the democratic school in Aarau, where freedom and autonomy were secured, he was able to achieve emotional stability. For a long time, the city Aarau prevailed as a location of tolerance and multi-culturalism, without religious, regional, and national discrimination. This was possible due to the influence of external and unrestricted social mobility, as well as the Enlightenment from France. As a result, this small public school was able to acquire a mass of qualified human resources from outside of Switzerland. As a consequence of the controversy regarding the educational ideology, the Cantonal School adopted practical thoughts and the Enlightenment that fit the spirit of the times. The school consisted of two independent educational organizations: the Gymnasium, where the 'neuhumanistsch' education for the elite training was conducted, and the 'Gewerbeschule', where a more realistic education system was set up to suit the citizen life. In particular, after 1835, the Gymnasium changed gradually from the pure humanistic education to the 'utraquistisch' ways by introducing practical subjects such as natural history. Thereafter, the Cantonal School became an institution that was able to achieve a genuine humanity, academic, and civic life education. Einstein, who attended the 'technische Abteilung' of the 'Gewerbeschule,' considered this school as a role model of an institution that realized true democracy, and that left an unforgettable impression on him.

• Journal of Korean Home Economics Education Association
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• v.33 no.3
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• pp.173-187
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• 2021

The purpose of this research was to develop instructions for making upcycled clothing accessories related to the 'clothing management and recycling' unit of middle school home economics applying the design thinking technique. Teaching and learning process plans were developed according to the ADDIE model which includes the following process: analysis, design, development, implementation, and evaluation. The design thinking process includes understanding the related knowledge, sympathizing, problem identification(sharing perspectives) and idea development, making prototypes, testing, and making the actual product. Thirteen home economics teachers served as critics. Student feedbacks were collected to evaluate whether the course objectives were attained after the implementation. As a result, teaching and learning process plans, course materials, and evaluation rubrics for ten class sessions were developed. Student feedbacks confirmed the attainment of following five course objectives: improvement of ethical responsibilities through the exploration of various clothing recycling techniques, practice of creative and eco-friendly clothing culture, acquisition of the skills to use sewing tools safely, improvement of abilities to think, sympathize, and communicate, and exploration of aesthetic activities and fashion careers.

• International Area Studies Review
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• v.22 no.3
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• pp.175-200
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• 2018

Since the 1990s rising intangible asset has become one of the main driving forces of investment stagnation and jobless growth in advanced income countries. We investigate how does the impact of firms' profitability on employment growth depends on the intangibility and whether the relationship between profitability and tangibility has complementarity. With data on Korean firms over the period 1988~2017 we investigate the effects of intangibility and profitability on employment growth based on the econometric approach of system GMM. The empirical results are as follows. (1) the profit rate has gradually led to lower employment growth, while it had positive effect on employment before the period of financial crisis. The estimated values and signs of profit rate coefficients varies from traditional industries to high/medium tech. industries. (2) the effect of increasing asset intangibility ratio on employment growth is negative and statistically significant. (3) the coefficients of interaction term of (profit rate ${\times}$ intangibility ratio) have significant negative values. It means employment effect of profit rate are becoming higher(lower) as intangibility ratio is at the lower(higher) level; profits rate and intangibility are not complement with each other. The results imply that to boost employment industrial policy which has the capacity to coordinate business intangibility is preferred to expansionary demand policy.

• (The)Study of the Eastern Classic
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• no.32
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• pp.391-424
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• 2008

A Buddhist relic deposit was discovered from the three storied stone pagoda which was called as Seokgatap of Bulguksa temple in Gyeongju in 1966. In this relic deposit, several clumped papers written in ink which were found from the pagoda. These manuscripts are one of the most valuable materials for understanding Korean Buddhism and Buddhist Art History. In this paper, I examined several terms for pagoda subsidiaries found in these manuscripts, which have not been known to us up to recently. In addition, I compared these terms to the real pagodas or pagoda images in Korea. The manuscripts from Seokgatap pagdoa were composed of three different kinds of records; (1) "Record for the Repair of Mugujeonggwangtap Pagoda (無垢淨光塔重修記, 1024)"; (2)"Record for the Reconstruction of West Pagoda (西石塔重修形止記, 1038); (3)"Lists of Donors for the Reconstruction of the Pagoda in Bulguksa temple (佛國寺塔重修布施名公衆僧小名記, 1038). The terminology describing pagoda was appeared in the first and the second records. In the "Record for the Repair of Mugujeonggwangtap Pagoda", there are more than ten terms, which are presumed to be the words describing some upper decorative parts of a stone pagoda. However, in the "Record for the Reconstruction of West Pagoda", there are fifteen terms which would describe the body and base parts of the Seokgatap pagoda. These new terms for pagoda subsidiaries appeared in the manuscripts of Seokgatap Pagoda are very significant materials in understanding Korean Buddhist Art, because they show the practical terms which were used in the eleventh century Buddhism of Korea, but never known to the modern academic world. The manuscripts of Seokgatap Pagoda have not been deciphered perfectly yet, so they have to be examined with more precise as well as with wider view of Buddist and Art History.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.585-600
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• 2012

Security issues in online games are increasing as the online game industry grows. Real money trading (RMT) by online game users has become a security issue in several countries including Korea because RMT is related to criminal activities such as money laundering or tax evasion. RMT-related activities are done by professional work forces, namely gold-farmers, and many of them employ the automated program, bot, to gain cyber asset in a quick and efficient way. Online game companies try to prevent the activities of gold-farmers using game bots detection algorithm and block their accounts or IP addresses. However, game bot detection algorithm can detect a part of gold-farmer's network and IP address blocking also can be detoured easily by using the virtual private server or IP spoofing. In this paper, we propose a method to detect gold-farmer groups by analyzing their connection patterns to the online game servers, particularly information on their routing and source locations. We verified that the proposed method can reveal gold-farmers' group effectively by analyzing real data from the famous MMORPG.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.133-141
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• 2021

Governments of each country are actively implementing fiscal expansion policies to recover the real economy after Corona 19. In Korea, the stock market and housing market are greatly affected as liquidity in the market increases due to the implementation of disaster subsidies and welfare policies. The purpose of this study is to analyze the relationship between stock market and housing market trends and liquidity. Data were collected by the Bank of Korea and Kookmin Bank. The analysis period is from January 2000 to December 2020, and monthly data are used. For empirical analysis, the rate of change from the same month of the previous year was calculated for each variable, and numerical analysis, index analysis, and model analysis were performed. As a result of the analysis, it was found that the stock index showed a positive(+) relationship with the house price, while a negative(-) relationship with M2. Previous studies have suggested that, in general, an increase in liquidity affects the stock market and the housing market, and inflation also rises. In this study, it was found that the stock market and the housing market had an effect on each other. However, it was investigated that liquidity showed an inverse relationship with the stock market and had no relationship with the housing market. Through this, this study estimated that there is a time difference in the relationship between liquidity and the stock market & housing market.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.2
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• pp.1-7
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• 2021

The concrete deck slab at the continuous span support of the steel box girder bridge is a structure that is combined with the upper flange. It is a structure that can cause tension cracks in the deck slab at the support causing problems such as durability degradation in long span bridges. This is because the tensile stress in the longitudinal direction of the slab exceeds the design tensile strength due to the effects of dead load and live load when applying a long span. Accordingly, it is necessary to control tensile cracking by adding a reinforcing bar in the axial direction to the slab at the support and to introduce additional compressive stress. To solve this problem, a structural system of a steel box girder bridge was proposed that introduces compressive stress as PS steel wire tension in the tensile stress section of the upper slab in the continuous support. The resulting structural performance was compared and verified through the finite element analysis and the steel wire tension test of the actual specimen. By introducing compressive stress that can control the tensile stress and cracking of the slab generated in the negative moment through the tension of the PS steel wire, it is possible to improve structural safety and strengthen durability compared to the existing steel box girder bridge.