• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.141-147
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• 2019

Recently, the biggest issue in the electricity industry is the increase in renewable energy, and various technologies are being developed to ensure the capacity of the power system. In addition, super-grids linking power systems are being pushed to utilize eco-friendly energy between countries and regions worldwide. The HVDC transmission technology is required to link the power network between regions with different characteristics of the power system such as frequency and voltage. Until now, Korea has applied HVDC transmission technology that connects mainland and Jeju Island with submarine cables. But, the HVDC transmission technology is still developing for long-distance high-capacity power transmission from power parks on the east coast to load-tight areas near the metropolitan area. Considering the high population density and mountainous domestic environment, it is pushing for commercialization of the design technology of the ${\pm}500kV$ Double Bipole with metallic return wire transmission line to transmit large-scale power of 8 GW using minimal right of ways. In this paper, the insulation characteristics were studied for the design of double-bipole transmission tower with metallic return wire, which is the first time in the world. And the air insulation characteristics resistant to the various overvoltage phenomena occurring on transmission lines were verified through a full-scale impulse voltage test.

• Food Science and Preservation
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• v.18 no.6
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• pp.853-858
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• 2011

Soybean-based food items have been developed as common fermented side dish sauces in South Korea, Japan, and China. Each of these countries, however, has its own fermentation method, including a microorganism-based fermentation process, the mixing of ingredients, the fermentation process, and the mixing of starch. The purpose of this study was to determine the quality characteristics of the commercial product. Fourteen kinds of rice soybean paste (Korea, 2 Japan, 12) were prepared, and their physiochemical properties (ammonium nitrogen, amino nitrogen, amylase, protease, and reducing-sugar contents) were analyzed. JRD-1 was found to contain the highest amount of amino-type nitrogen (426.45 mg%) while KRD-2 showed 316.10 mg%. For the protease activities, the following results were obtained: JRD-9, 695.10 unit/g JRD-11, 671.45 unit/g and JRD-5, 665.03 unit/g. As for the amylase activities, the results that were obtained were JRD-7, 53.65 unit/g JRD-8, 50.71 unit/g KRD-1, 46.52 unit/g JRD-1, 46.29 unit/g and JRD-11, 33.61 unit/g. This research provided information for the quality characteristics of commercial rice soybean paste.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.5
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• pp.349-361
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• 2021

With the development of technology and the advancement of weather forecasting models and prediction methods, higher performance weather forecasting software has been developed, and more precise and accurate weather forecasting is possible by performing software using supercomputers. In this paper, the weather forecast model used by six major countries is investigated and its characteristics are analyzed, and the Korea Meteorological Administration currently uses it in collaboration with the UK Meteorological Administration since 2012 and explains the GloSea However, the existing GloSea was conducted only on the Meteorological Administration supercomputer, making it difficult for various researchers to perform detailed research by specialized field. Therefore, this paper aims to establish a standard experimental environment in which the low-resolution version based on GloSea6 currently used in Korea can be used in local systems and test it to present the localization of low-resolution GloSea6 that can be performed in the laboratory environment. In other words, in this paper, the local portability of low-resolution Globe6 is verified by establishing a basic architecture consisting of a user terminal-calculation server-repository server and performing execution tests of the software.

• Journal of the Korean GEO-environmental Society
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• v.22 no.11
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• pp.15-21
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• 2021

Losses of both life and property increased from damage to underground pipe such as heat transmission pipe buried underground in downtown because pipes are gradually aging. Considering the characteristics of the heat transmission pipe, which is not exposed to the outside and difficult to immediately identify problems such as damage, it is realistic to indirectly check the condition of the facility based on the historical information that is periodically collected through facility maintenance. In this study, a methodology for estimating the damage probability was developed by examining the history information of the heat transmission pipe, deriving an evaluation factor that is related to the damage probability. The contribution factor of the damage probability were reviewed by analyzing not only the guidelines for maintenance of heat transmission pipe of advanced European countries and domestic district heating companies, but also the cases of waterworks with similar characteristics. Evaluation factors were selected by considering not only the correlation with the damage probability but also the possibility of securing data. Based on 1999, when the construction technology and standards of heat transmission pipe changed, the damage probability estimation function according to the period of use was divided into the case of being buried before 1998 and the case of being buried after 1999, and presented. In addition, the damage probability was corrected by assigning weights according to the measured data for each evaluation factor such as the diameter, use, and management authority.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.176-183
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• 2021

Digital medical technology is very effective and at the same time faces the challenge of protecting privacy. However, for contact tracking and exposure notification apps in COVID-19 environment, there is always a trade-off between privacy measures and the effectiveness of the app's use. Today, many countries have developed and used contact tracking and exposure notification apps in various forms to prevent the spread of COVID-19, but the suspicion of digital surveillance (digital panopticon) is unavoidable. Therefore, this study aims to identify the factors of personal information infringement and dissatisfaction through text mining analysis by extracting user reviews of "Self-Quarantine Safety Protection" in Korea. As a result of the text mining analysis, we derived four groups, 'Address recognition error', 'Exit warning error', 'Access error', and 'App. program error'. Since 'Address recognition error' and 'Exit warning error' can give the app users a strong perception that they are keeping under surveillanc by the app, transparent management of personal information protection and consent procedures related to personal information collection are required. In addition, if the other two groups are not corrected immediately due to an error in an app function or a program bug, the complaints of users can be maximized and a protest against the monitor can be raised.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.65-74
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• 2021

In order to efficiently inspect rapidly increasing old tunnels in many well-developed countries, many inspection methodologies have been proposed using imaging equipment and image processing. However, most of the existing methodologies evaluated their performance on a clean concrete surface with a limited area where other objects do not exist. Therefore, this paper proposes a 6-step framework for tunnel crack detection deep learning model development. The proposed method is mainly based on negative sample (non-crack object) training and Cascade Mask R-CNN. The proposed framework consists of six steps: searching for cracks in images captured from real tunnels, labeling cracks in pixel level, training a deep learning model, collecting non-crack objects, retraining the deep learning model with the collected non-crack objects, and constructing final training dataset. To implement the proposed framework, Cascade Mask R-CNN, an instance segmentation model, was trained with 1561 general crack images and 206 non-crack images. In order to examine the applicability of the trained model to the real-world tunnel crack detection, field testing is conducted on tunnel spans with a length of about 200m where electric wires and lights are prevalent. In the experimental result, the trained model showed 99% precision and 92% recall, which shows the excellent field applicability of the proposed framework.

• Journal of Korea Port Economic Association
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• v.37 no.1
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• pp.143-157
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• 2021

International organizations such as the World Health Organization, the Organization for Economic Development and Cooperation, and major developed countries recognize the seriousness of air pollution. International organizations such as the International Maritime Organization have also implemented various regulations to reduce air pollution from ships. In line with this international trend, the government has also enacted a special law on improving air quality in port areas, and is making efforts to reduce air pollution caused by ports. The purpose of the Special Act is to implement comprehensive policies to improve air quality in port areas. This study sought to identify the emissions of each source of air pollutants originating from the port and prepare basic data on setting the policy priorities. To this end, the analysis was conducted in six categories: ships, vehicles, loading and unloading equipment, railways, unloading/wild ash dust, road ash dust, and the methodology presented by the European Environment Agency(EEA) and the United States Environmental Protection Agency(EPA). The pollutants subject to analysis were analyzed for carbon monoxide(CO), nitrogen oxides (NOX), sulfur oxides(SOX), total airborne materials(TSP), particulate matter(PM10, PM2.5), and ammonia(NH3). The analysis showed a total of 7,122 tons of emissions. By substance, NOX accounted for the largest portion of 5,084 tons, followed by CO (984 tons), SOX (530 tons), and TSP (335 tons). By source of emissions, ships accounted for the largest portion with 4,107 tons, followed by vehicles with 2,622 tons, showing high emissions. This proved to be the main cause of port air pollution, with 57.6% and 36.8% of total emissions, respectively, suggesting the need for countermeasures against these sources.

• (The) Research of the performance art and culture
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• no.18
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• pp.449-480
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• 2009

In this paper, I tried to study the change of the Chinese performing arts market during the 10th 5year development plan, from year 2001 to year 2005 by both of the quantitative and qualitative analysis, because it's really the time when we need to understand the growing market of chinese culture along with the development of the Chinese cultural industry. During that period, the Chinese government developed the policy to establish a healthy cultural market and strengthen it's cultural power; the parts who product the piece of performing arts including the performing troupes, the theatres and the production companies were consolidated and became familiar to market through the reformation of the organization; and the audience who consume the performing arts and entertainments still shows very Chinese characteristics in the cities and villages. In the village, the audiences invite the troupe to play their local theatre in many occasions of their life according to their traditional beliefs, also somehow to show their wealth. The fact that the local governments and the companies are very important consumer groups in China is also very 'Chinese' characteristics. It means that Chinese performing arts are still more or less under the influence of the political ideas. Nonetheless it is worthy of notice that Chinese performing arts not only develope the new contents in very creative way and also try to learn the knowhow of the excellent items of foreign countries by inviting them to the festivals or organize a co-productions on the basis of the upgraded cultural power through the 10th 5 year development plan.

• Asian Spine Journal
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• v.12 no.6
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• pp.1106-1116
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• 2018

Study Design: Prospective observational study. Purpose: To evaluate the disability domains relevant to Indian patients with low backache and propose a modified disability questionnaire for such patients. Overview of Literature: The Oswestry Disability Index (ODI) is a self-reported measurement tool that measures both pain and functional status and is used for evaluating disability caused by lower backache. Although ODI remains a good tool for disability assessment, from the Indian perspective questions related to weight lifting and sexual activity of ODI are questioned in some of the earlier studies. Activities of daily living in Indian patients vary substantially from those in other populations and include activities like bending forwards, sitting in floor and squatting which are not represented in the ODI. Methods: In this prospective observational study, a seven-step approach was used for the development of a questionnaire. Thirty patients were interviewed to identify the most challenging issue they faced while performing their daily activities (by free listing) and understand how important the questionnaire items were in terms of the standard ODI. Thus, a comprehensive disability questionnaire comprising 14 questions was developed and administered to 88 patients. Both qualitative (interviews) and quantitative methods (to establish the validity, reliability, and correlation with the Visual Analog Scale [VAS] and Rolland Morris disability questionnaire) were used to identify the 10 questions that best addressed the disability domains relevant to Indian patients. Results: According to free listing, four new questions pertaining to bending forward, sitting on the floor, walking on uneven surfaces, and work-related disabilities were included. In the second phase, wherein the questionnaire with 14 items was used, 56.8% patients did not answer the questions related to sexual activity, whereas 23.8% did not answer those related to walking on uneven surfaces. The modified questionnaire demonstrated good internal consistency (Cronbach's alpha=0.892) and correlation with the Rolland Morris questionnaire (Cronbach's alpha=0.850, p>0.05), as well as with the VAS score for disability (Cronbach's alpha=0.712, p>0.05) and pain (Cronbach's alpha=0.625, p>0.05). Conclusions: A modified disability questionnaire that was designed by adding two questions related to bending forward and work status and removing questions related to sexual activity and weight lifting or traveling (depending on the occupation) can help evaluate disability caused by back pain in Indian population.

• Survey Research
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• v.18 no.4
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• pp.127-147
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• 2017

Despite the importance of questionnaires, little survey methodology research on questionnaire design has been conducted in Korea. The purpose of this study was to explore whether two questionnaire forms (close-ended vs. open-ended questions) about 'the most important problem in Korea' elicited similar responses. During the 2016 Korean General Social Survey (KGSS), a random half of respondents were asked the open-ended question form and the remaining half were asked the close-ended question form. While the economy is the most mentioned response (35% vs. 33.2%) to both close-ended and open-ended question forms, there is similarity in the order of highly mentioned responses if we consider that 'politics' is not provided as one of response categories in the close-ended question form. The order of second to fourth response category is crime (24.4%), education (15.4%), and poverty (6.3%) to the closed-ended question form, and politics (10.8%), crime (9.5%), and education (7.6%) to the open-ended question form. Also, the characteristics of respondents who responded with the economy as being the most important are slightly different between the two halves in terms of age, household income, and satisfaction with economic condition. Our findings suggest that we need to be careful when we adopt questions developed in other countries and to consider using survey experiments in pre-testing questionnaire items.