• Journal of Conservation Science
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• v.35 no.3
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• pp.217-225
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• 2019

The chimi(ridge-end tile) of Wangheungsa temple is the oldest in our country. The upper part of the chimi was excavated from the southern side of Wangheungsa temple and the lower part from the northern side. These parts are considered to be portions of the same chimi, because they are similar in shape and are excavated from two sides of the same temple structure. However, the original shape of the chimi cannot be determined owing to substantial deterioration. Hence, in this study, replicas of the deteriorated chimi portions of Wangheungsa temple were fabricated by employing 3D scanning technology and the computer numerical control machining method. While observing the bending phenomenon of the chimi, the proposed model was warped realistically on the basis of the bending direction of the actual chimi. Consequently, the restoration process was modified several times. The results indicated that no gaps can be found between the upper and lower parts, and the corresponding patterns connect naturally. Furthermore, the proposed method is contactless, safe, operable, reproducible, and appropriate for restoration of artifacts. Additionally, the modeling data is semi-permanent. Hence, if modelling data is appropriately applied as per the characteristics of artifacts, it can be utilized in various fields such as virtual exhibitions, hands-on exhibitions, cultural heritage restoration, and production of teaching aids and souvenirs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.887-895
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• 2018

This paper presents a braking model that can be used to design the safety distance of a train control system and a train braking system to increase the volume of traffic. For the braking model, a train set (electric multiple unit composed 6 cars) was tested. The factors that can affect the braking characteristics include the friction coefficient, braking pressure, and regenerative braking. The braking pressure was classified into service and emergency braking and reflected the characteristics of the vehicle. The external force acting on the running railway car was tested in accordance with KS R 9217, and the running resistance of the train is presented in the form of a polynomial. The dynamic behavior of the train running on a straight flat line was simulated using UM 8.3. The results were validated with experimental data, and the results were reasonable. With the validated model, a stopping distance was determined according to the initial braking speed and compared with the deceleration braking model. In addition, a safety distance for the train control system could be changed according to the frictional coefficient limits. These results are expected to be useful for analyzing the dynamic behavior of trains, and for analyzing various railway environments and improving the braking performance.

• Journal of Industrial Convergence
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• v.19 no.5
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• pp.21-34
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• 2021

The purpose of this study is to find out what the investment efficiency of BW is from an investor's point of view and to suggest an efficient investment plan to investors. The research method is to investigate the coupon interest rate, maturity interest rate, issuance date, right exercise start and end date, maturity date, exercise price, etc. for BW issued from 2014 to July 2021. By connecting them, it was attempted to quantitatively understand the efficiency of investment in BW and the effect of new stock acquisitions. As a result of the study, the ratio of the number of days in excess of the exercise price was 41.3% of the available days for new stocks, so it was analyzed that the investment efficiency of bonds with warrants was not high. The return on the exercise start date was 24.8% on average and the return on the end date was 52.6% on average, showing a positive return on average, so it was derived in line with investor expectations. The number of stocks with negative returns on the exercise start date was 1.47 times higher than the number of stocks with positive returns, and the number of stocks with negative returns on the end date was 1.16 times higher than the number of positive stocks.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.796-805
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• 2020

Purpose: A static loading test was performed to evaluate the ultimate flexural strength of a girder in which 80MPa high-strength concrete was synthesized on the compressive flange of the I-shape steel girder. Method: This test is designed and fabricated two types of specimens with different shear-connection specifications, and evaluated their ultimate flexural behavior until reaching the extreme event limit states. In addition, the ultimate strength was evaluated by comparing the test results and the results of the strain compatibility method. Result: By confirming the displacement within 0.02mm as a result of the relative slip measurement, it was verified that the two specimens secured perfect bonding. Therefore, the difference in the shear specification does not have a great effect on the stiffness, and if the specimens are completely synthesized, there is no difference in the behavior until it reaches the extreme-event limit states. Conclusion: The girder to be tested has a working load within the elastic range and meets the usability requirements for allowable deflection. Therefore, even if a part of the casing is subjected to the tensile force at the level of cracking, the deck will first reach the compression failure due to the role of the reinforcing bar.

• Journal of Science Education
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• v.45 no.1
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• pp.1-10
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• 2021

In this study, we analyzed the relationship between the physical science domain of TIMSS 2019 and the Korean science curriculum. Twelve subjects are presented in the physical science domain of the TIMSS 2019 4th grade evaluation framework. Research group consisting of elementary and middle school teachers and science education experts, a total of 12, participated to analyze in which grade these subjects were included in the Korea 2009 revised and 2015 revised science curriculum. As a results of analyzing whether the achievement standards of the TIMSS 2019 evaluation framework and Korean science curriculum are consistent, the subjects pertinent to chemistry like 'chemical changes in everyday life,' 'heat transfer,' and 'electricity and simple electrical circuits' appeared not covered at all until the 4th grade curriculum in Korea. Given that the TIMSS 2019 evaluation framework is an international achievement standard, we are proposing to improve the Korean curriculum as follows: first, for the development of the next science curriculum, there is a need for science curriculum organized from the 1st grade of elementary school to connect the content and scope of chemistry in elementary, middle, and high schools as a whole including the Nuri curriculum. Second, as an alternative to the problem of suitability of learning volume and level of learning, it is possible to think of a method to readjust the grade of dealing with related concepts by lowering the difficulty or simplifying the concept. Third, it is necessary to discuss about introducing essential concepts and standard terms into Korea science curriculum according to international trends.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.248-248
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• 2018

새만금 종합개발계획(정부, 2011)에 따른 내부개발의 완료시점은 2030년이며, 방수제 공사와 준설 등과 같이 만경강 및 동진강 유역 내 흐름을 변화시킬 수 있는 공사를 포함하고 있으므로 현재와 2030년의 하천 및 호의 수리특성은 다를 것이라 예상된다. 2030년까지 준설상황 등을 예측하여 반영하는 것은 사실상 불가능하기 때문에 새만금 종합개발계획에서 제시하고 있는 내부개발의 완료시점을 기준으로 홍수사상을 모의하였다. 새만금 호의 물리적인 변화는 수리특성의 변화로 이어질 수 있으며, 이는 상류지역으로 전파가 될 수 있으므로 호내 뿐만 아니라 만경강과 동진강 전역에 대한 홍수시의 수리특성을 검토하였다. 새만금 호와 연결된 만경강과 동진강의 설계홍수량은 대부분의 구간에서 100년 빈도이기 때문에 본 연구에서는 100년 빈도 홍수사상에 대한 분석을 기초로 홍수위 검토를 수행하였고, RCP8.5 시나리오를 적용한 100년 빈도 홍수량과 500년 빈도 홍수량에 대한 추가적인 연구를 수행하였으며, 이 결과를 토대로 취약지구 분석 및 대책 등을 제시하였다. 수치모의는 Delft3D를 이용하였으며, 새만금 유역의 동진강 지구의 실측치와 비교함으로써 모델의 적용성을 검증하였다. 서해안 조위 특성상 새만금 방조제는 조위 영향이 크므로, 이에 본 연구에서는 외조위의 특성을 고려하기 위해 새만금 유역 주변의 12개 조화상수(tidal harmonic constant)를 이용하여 조위에 대한 모의를 별도로 수행하고, 이 결과를 배수갑문의 경계조건으로 이용하였다. 상류 경계조건은 하천기본계획상에 제시된 하천은 이를 이용하였으며, 그 외의 소하천은 유역면적을 이용한 계산법을 사용하여, 선형적 면적 비유량(Specific Discharge, SD) 방법을 적용하여 본류의 유량에 부가하는 방식으로 수행하였다. 수치해석 결과, 준설 구간의 수위는 전반적으로 저하되었으며, 거리에 따른 수면의 경사를 분석한 결과 기존의 하천구역이 준설 등으로 인하여 호수의 특성으로 변화된 것으로 확인하였다. 본 연구에서 취약지구는 홍수위가 제방고의 약 80% 이상 되는 지역으로 결정하였으며, 이를 토대로 취약지구 분석을 수행한 결과 기존 100년 빈도에서 1지점, RCP 8.5 시나리오가 적용된 100년 빈도에서 88지점, 500년 빈도에서 125지점이 잠재적인 치수 위험이 있는 것으로 파악되었다. 기존의 1차원 연구결과와는 차이가 있는 부분은, 다수의 취약지구가 만곡부 또는 합류부 인근에 위치한 것이다. 향후 이러한 상대적인 치수 취약지점에 대해 정밀하고 국부적인 연구를 수행하여 정확한 홍수위 예측을 수행해야 할 것이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.475-486
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• 2021

The purpose of this study was to propose a policy direction to improve the service of public bicycles in Seoul by identifying the physical characteristics that affect the satisfaction level in the Seoul Metropolitan Government's public bicycle use environment. To this end, a survey was conducted on users regarding their experiences using public bicycles in Seoul, and the responses of 567 people were analyzed. IPA analysis and ordinal logistic analysis were used. An analysis of the Seoul Metropolitan Government's public bicycle IPA showed that the satisfaction level was lower than that of importance in all categories. Among them, the most urgent need for improvement was the installation of bicycle roads, improved connectivity of bicycle roads, improved road management, classification of roads and bicycle roads, improved safety during night driving, and low satisfaction levels. Second, an analysis of the factors affecting the satisfaction in the public bicycle use environment showed that the model's explanatory power increased significantly from 0.062 to 0.437 after incorporating perceived variables, confirming that the perceived neighborhood environment characteristics are an important variable for determining the satisfaction level in the public bicycle use environment, among the perceived neighborhood environmental characteristics, accessibility, convenience, manageability.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.69-81
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• 2021

Coastal shipping performs a pivotal role as a national transportation network and is highly valuable in terms of enabling more economical transportation at affordable prices than road transportation. In this regard, this study aimed to examine changes in the characteristics and centrality of South Korea's costal shipping sea-route networks by analyzing the centrality of domestic coastal shipping. To this end, social network analysis was used as an analysis technique that enables an analysis on the characteristics of coastal shipping networks. As a result, Jeollanam-do showed the highest degree centrality, ranking first in both the in-degree and the out-degree. Jeollanam-do also exhibited the highest betweenness centrality, and Gangwon-do registered the highest closeness centrality. In terms of hub and authority centrality, Jeollanam-do topped the list, followed by Gyeongsangnam-do and Gangwon-do in order. Lastly, Jeollanam-do ranked highest in the hub index, followed by Incheon, other regions, and Gangwon-do in order. This study is significant for suggesting the cities and provinces that play a key role in coastal shipping each year and their corresponding items. Future studies are recommended to identify the trend of coastal shipping through more detailed research on each port by city and province.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.119-131
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• 2021

This study quantitatively derived the direct socio-economic effects of the Gyeongbu Expressway, which opened in 1970, and suggested a methodological approach for more reliable results. The scenario was set when the Gyeongbu Expressway was not constructed in 1970, the opening of the Gyeongbu Expressway was delayed by 10 years, and the toll road between Seoul and Daejeon, or between Seoul and Gangneung was opened instead of the Gyeongbu Expressway as suggested by the World Bank. In addition, direct benefits were estimated by calculating and comparing the current vehicle operating costs, travel time costs, traffic accident costs, and environmental pollution costs. As a result, it was estimated that about 351 trillion won in direct benefits occurred, and it can be seen that the promotion of the construction project of the Gyeongbu Expressway at that time had a huge impact on South Korea's social economy.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.3
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• pp.193-200
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• 2021

Recently, posts and opinions on tourist attractions are actively shared on social media. These social big data provide meaningful information to identify objective images of tourist destinations recognized by consumers. Therefore, an in-depth understanding of the tourist image is possible by analyzing these big data on tourism. The study is to analyze destination images in Gangwon-do using big data from social media. It is wanted to understand destination images in Gangwon-do using semantic network analysis and then provided suggestions on how to enhance image to secure differentiated competitiveness as a destination for tourists. According to the frequency analysis results, as tourism in Gangwon-do, Sokcho, Gangneung, and Yangyang were mentioned at a high level in that order, and the purpose of travel was restaurant tour, gourmet food, family trip, vacation, and experience. In particular, it was found that they preferred day trips, weekends, and experiences. Four suggestions were made based on the results. First, it is necessary to develop various types of hotels, accommodation facilities and experience-oriented tour packages. Second, it is necessary to develop a day-to-day travel package that utilizes proximity to the Seoul metropolitan area. Third, it is necessary to promote traditional restaurants and local food. Finally, it is necessary to develop tourist package suitable for healing and family travel. Through this research, the destination image of Gangwon-do was identified and a tourism marketing strategy was presented to improve competitiveness. It also provided a theoretical basis for the use of the big data of tourism consumers in the field of tourism business.