• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.6
• /
• pp.599-609
• /
• 2021

A novel grounding system, which is presented in IEC 60364, has been adopted since 2021. A safety evaluation for the human body on the grounding system is required due to the various characteristics of the touch voltage and current passing when the human body experiences an electric shock. The Korea Electrical Safety Corporation (KESCO) and Korea Electric Association (KEA) have been conducting a safety technical education on the grounding system. On the other hand, it is difficult to instruct the electrical safety manager because of a lack of safety evaluations for the test equipment on the grounding system. Therefore, this paper modeled and implemented a test device for a safety evaluation depending on the grounding system of IEC 60364. Namely, this paper presents the modeling of the test device for a safety evaluation using PSCAD/EMTDC S/W, which is composed of an AC grid section, s test device section on the grounding system, and a sub-device section. This paper implemented a test device for safety evaluation, which consisted of an AC grid section, TT grounding system section, TN-S grounding system section, and monitoring section. From the simulation and test results with the safety characteristics of the human body in the TT and TN-S grounding system, when the fault impedances are 0[Ω], 10[Ω], and 100[Ω], the currents passing through the human body in the TT grounding system are 104[mA], 87.4[mA], and 35.5[mA], respectively. The corresponding currents in the TN-S grounding system are 54.9[mA], 4.1[mA], and 0.4[mA], respectively. Based on the results, the protection performance for an electric shock to the human body in the TN-S system is better than the TT system. This can be improved when the existing grounding system is changed from the TT system to the TN-S system.

• Atmosphere
• /
• v.31 no.2
• /
• pp.229-240
• /
• 2021

The Global Ocean Data Assimilation and Prediction System (GODAPS) in operation at the KMA (Korea Meteorological Administration) is introduced. GODAPS consists of ocean model, ice model, and 3-d variational ocean data assimilation system. GODAPS assimilates conventional and satellite observations for sea surface temperature and height, observations of sea-ice concentration, as well as temperature and salinity profiles for the ocean using a 24-hour data assimilation window. It finally produces ocean analysis fields with a resolution of 0.25 ORCA (tripolar) grid and 75-layer in depth. This analysis is used for providing a boundary condition for the atmospheric model of the KMA Global Seasonal Forecasting System version 5 (GloSea5) in addition to monitoring on the global ocean and ice. For the purpose of evaluating the quality of ocean analysis produced by GODAPS, a one-year data assimilation experiment was performed. Assimilation of global observing system in GODAPS results in producing improved analysis and forecast fields with reduced error in terms of RMSE of innovation and analysis increment. In addition, comparison with an unassimilated experiment shows a mostly positive impact, especially over the region with large oceanic variability.

• Korean Journal of Remote Sensing
• /
• v.37 no.3
• /
• pp.531-542
• /
• 2021

Open-pit mines require constant monitoring as they can cause surface changes and environmental disturbances. In open-pit mines, there is little vegetation at the mining site and can be monitored using InSAR (Interferometric Synthetic Aperture Radar) coherence imageries. In this study, activities occurring in mine were analyzed by applying the recently developed InSAR coherence-based NDAI (Normalized Difference Activity Index). The March 5 Youth Mine is a North Korean mine whose development has been expanded since 2008. NDAI analysis was performed with InSAR coherence imageries obtained using Sentinel-1 SAR images taken at 12-day intervals in the March 5 Youth Mine. First, the area where the elevation decreased by about 75.24 m and increased by about 9.85 m over the 14 years from 2000 was defined as the mining site and the tailings piles. Then, the NDAI images were used for time series analysis at various time intervals. Over the entire period (2017-2019), average mining activity was relatively active at the center of the mining area. In order to find out more detailed changes in the surface activity of the mine, the time interval was reduced and the activity was observed over a 1-year period. In 2017, we analyzed changes in mining operations before and after artificial earthquakes based on seismic data and NDAI images. After the large-scale blasting that occurred on 30 April 2017, activity was detected west of the mining area. It is estimated that the size of the mining area was enlarged by two blasts on 30 September 2017. The time-averaged NDAI images used to perform detailed time-series analysis were generated over a period of 1 year and 4 months, and then composited into RGB images. Annual analysis of activity confirmed an active region in the northeast of the mining area in 2018 and found the characteristic activity of the expansion of tailings piles in 2019. Time series analysis using NDAI was able to detect random surface changes in open-pit mines that are difficult to identify with optical images. Especially in areas where in situ data is not available, remote sensing can effectively perform mining activity analysis.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.2
• /
• pp.136-153
• /
• 2021

The restitution of cultural heritage located abroad has been going on for 107 years, starting with the return of the Jigwangguksa Tower to Beopcheonsaji Temple in Wonju after it was taken during the Japanese occupation in 1915. The Overseas Cultural Heritage Foundation, established in 2012, has laid the foundation for retrieval, preservation, restoration, and exchange of cultural heritage through research cooperation and the purchasing of cultural heritage items. The pace of the collection of cultural heritage objects and the locating of others has increased every year since its establishment, and the number of returned, rather than recovered, cultural heritage items has also increased. The present study aimed to complete a value inquiry of the cultural relics of Waryongmae (臥龍梅) and a restitution of cultural heritage as the main focuses. The process of recovering relics from Waryongmae has been recorded in the book The Cultural Property Returned into Our Arms, published by the above-mentioned foundation. This record was revised and supplemented to try and raise its cultural value by adding elaborate storytelling to the process of recovering the Waryongmae that grew in the courtyard of Changdeokgung Palace. The cultural value of Waryongmae is that it is unique. The Waryongmae is the first living cultural heritage, and therefore has cultural value due to its uniqueness. Second, the Waryongmae has unique cultural value due to its restitution and return to Korea twice, once in 1992, and another time in 1999. The first restitution was special in that it was featured by the Japanese media, and the second was special in that it was intensively reported by the Korean media. Third, 42 Waryongmae cultural content types were explored, including nineteen visual contents, eleven interactive contents, and twelve skate contents.

• Journal of the Society of Disaster Information
• /
• v.17 no.1
• /
• pp.10-24
• /
• 2021

Purpose: The purpose of this study is to determine the dangers of biodiesel and general diesel mixtures currently used as alternative fuels by equipment (tag method and penski Marten method) and to determine the difference between flash point and combustion point (closed, open) according to test methods. It is intended to be used as a reference material for identification and evaluation of firecausing substances by confirming the risk of mixtures by comparative analysis and measurement, and establishing a risk assessment method for chemical substances. Method: Flash point test method and result treatment were tested based on ASTM and KS M mode, which are tag sealing and pen schematense test methods used as flash point and combustion point test methods for crude oil and petroleum products. The manufacturer of the equipment used in this experiment was a test equipment that satisfies the test standards of KS M 2010 with equipment produced by TANAKA of Japan. The flash point and combustion point were measured, and the flash point according to the test method of biodiesel and general diesel mixture ( Closed, open), and the ignition point of a mixture of biodiesel and general diesel was compared and analyzed for ignition risk compared with conventional diesel. Results: Looking at the experimental results, first, as an analysis of the risk of flammability of the mixture, the flash point of a substance containing 70% biodiesel was found to be about 92℃ based on general diesel with a flash point of 64.5℃, and gasoline and biodiesel or When the biodiesel mixture was synthesized, it was confirmed that the flash point tends to decrease. In addition, the difference between the flash point and the combustion point was analyzed as about 20 ~ 30℃, and when a small amount of gasoline or methanol was mixed, the flash point was lowered, but it was confirmed that the combustion point was similar to that of the existing mixture. Conclusion: In this study, in order to secure the effectiveness of the details of the criteria for judging dangerous materials in the existing Dangerous Materials Safety Management Act, and to secure the reliability and reproducibility of the judgment of dangerous materials, we confirm the criteria for judging the risk of the mixture through an experimental study on flammable mixtures. It will be able to provide reference data for experimental criteria for flammable liquids that are regulated in the field. In addition, if this study accumulates know-how on experiment by test method, it is expected that it can be used as a basis for research on risk assessment and research on dangerous goods.

• Journal of the Society of Disaster Information
• /
• v.16 no.4
• /
• pp.701-711
• /
• 2020

Purpose: In this study, the risk of flammability of a liquid mixture was experimentally confirmed because the purpose of this study was to confirm the increase or decrease of the flammability risk in a mixture of two substances (combustible+combustible) and to present the risk of the mixture. Method: Flash point test method and result processing were tested based on KS M 2010-2008, a tag sealing test method used as a flash point test method for crude oil and petroleum products. The manufacturer of the equipment used in this experiment was Japan's TANAKA. The flash point was measured with a test equipment that satisfies the test standards of KS M 2010 with equipment produced by the company, and LP gas was used as the ignition source and water as the cooling water. In addition, when measuring the flash point, the temperature of the cooling water was tested using cooling water of about 2℃. Results: First of all, in the case of flammable + combustible mixtures, there was little change in flash point if the flash point difference between the two substances was not large, and if the flash point difference between the two substances was low, the flash point tended to increase as the number of substances with high flash point increased. However, in the case of toluene and methanol, the flash point of the mixture was lower than that of the material with a lower flash point. Also, in the case of a paint thinner, it was not easy to predict the flash point of the material because it was composed of a mixture, but as a result of experimental measurement, it was measured between -24℃ and 7℃. Conclusion: The results of this study are to determine the risk of mixtures through experimental studies on flammable mixtures for the purpose of securing the effectiveness of the details of the criteria for determining dangerous goods in the existing dangerous goods safety management method and securing the reliability and reproducibility of the determination of dangerous goods Criteria have been presented, and reference data on experimental criteria for flammable liquids that are regulated in firefighting sites can be provided. In addition, if this study accumulates know-how on differences in test methods, it is expected that it can be used as a basis for research on risk assessment of dangerous goods and as a basis for research on dangerous goods determination.

• Journal of Korean Society of Forest Science
• /
• v.100 no.3
• /
• pp.423-431
• /
• 2011

The changes of forest degradation in North Korea have closely been related to political, economic and social conditions at all different times. The deforestation by local people for their livelihood has been accelerated when the recession has been worsened due to the 1990's collapse of socialism and the years of natural disasters, and the fall of the centralized and planned economy system. The serious recession in the 1990's has brought many changes in the North Korean society since the 2000's. Not only the underground economy, but also the market in which personal trades are occurred have been expanded as the distribution system of the planned economy system had fallen. In addition, even many state institutions have also increased timber harvest for export to acquire insufficient foreign currency. Eventually, North Korea felt the limits of utilization of forest resources under socialism then started to seek measures to restore devastated forest, while realizing the need of support from the international society. Therefore, some NGOs of South Korea started to give financial support on building tree nurseries in which seedlings for planting are produced to help the rehabilitation of the degraded forests in North Korea. Therefore, Planning of the basic directions for forest rehabilitation programs considering to economic and social conditions of North Korea are needed based on the successful rehabilitation experience of South Korea in the 1970's. First of all, relationships which was built after collapse of centrally planned economy between districts, businesses and workers must be consider to rehabilitate forests in North Korea. Secondly, due to the nature of forest rehabilitation projects this is very needs voluntary participation of resident for a long time, and then forest rehabilitation projects can create jobs for local resident, they can obtain continuous income on the forest rehabilitation projects field in order to promote resident's work in forest rehabilitation projects. Thirdly, the rate dependence on forests of the residents living must keep the level down by rural development projects going side by side with forest rehabilitation projects. Fourthly, use of exsisting forest management system in North Korea is also needed to ensure administrative power and labor for grand scale plantations in a short period of time. Meanwhile after the success of Forest Rehabilitation, it is very important to improve exsisting forest management system.

• Journal of Korean Society of Forest Science
• /
• v.100 no.3
• /
• pp.522-534
• /
• 2011

The aim of this study is to draw forth the tasks for establishing the right of native biology in Korea through the case study on 'Access on genetic resources and Benefit Sharing'. For this purpose, this study decided on its research subject by selecting Hoodia, on which ABS treaty was made the most recently, through the examination of the representative ABS precedents on plant species. This study analyzed the process background of ABS on Hoodia, and compared & analyzed the ABS procedures of 'Bonn Guidelines' adopted by the 6th Conference of the Parties of the Convention on Biological Diversity in 2002 and Hoodia case. Together with the ABS major issues in common drawn as a result of this analysis, and "Nagoya Protocol" adopted by the 10th Conference of the Parties of the Convention on Biological Diversity, this study intended to shed a light on the impending tasks which Korea faces at present and its role relationship. The research results are as follows: 1. It is required that species habitats should be divided based on biological classification and its subsequent community should be established with the development of infrastructure such as a community's independent production, management and monitoring of bio-species. 2. There needs to be a designation of ABS National Focal Point for sharing of ABS-related general information, boosting of implementation of the relevant convention. 3. There needs to be the establishment of ABS convention system consequent on legislative, administrative, political procedures, and designation of the Competent National Authorities for the provision of the format of Prior Informed Consent (PIC) and Mutually Agreed Terms (MAT) and their contents assessment and confirmation. 4. There should be the establishment of integrated management system of ABS-related research and development of forest biological resources and its relevant research projects. 5. There should be information development through the distribution of responsibility and role between the ministries and offices concerned according to bio-resources, and there needs to be efforts in aiming for opening a working group of academic-industrial institutions for developing a mutually interchangeable system. 6. It's required that the efficient access between industrial circles and the people should be promoted by setting up ABS support center of biological resources in ministry and office's charge. 7. There should be a selection of a national supervisory organization for securement of the right of a local community and monitoring of ABS convention implementation, and a countermeasure system for preventing outflow of forest bioresources. Conclusively, it's judged that it will be possible to inquire into the countermeasures for the establishment of the native forest biology dominion through such research results.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.29 no.1
• /
• pp.50-58
• /
• 2011

Cheongpunggye is located in a valley where Baekaksan, the main mountain of Seoul and Inwang Mountain corresponding to right-white tiger(石白虎) divination based on topography are crossed. The owner of Cheongpunggye is Seonwon Kim Sangyong and many people had visited there without pause because of beautiful landscape since the early times of Chosun. Seonwon Kim Sangyong had ever studied together with Yulgok Yi I and Woogye Seong Hon. He was one of the Western faction(Seo-in) which was the leading power of Injo Coup and died for his chastity during Second Manchu Invasion of Chosun. He is known as a model of fidelity which is a symbol for scholar's spirit in Chosun together with his younger brother Cheongeum Kim Sangheon. Jangdong region, the clan village of New Andong family was the birthplace of Yulgok School which was the fundamental of scholar spirit of Chosun. And Jangdong would be the source of Jin-Gyeong(Real Scenery) Culture which was bloomed by Baekak club composed of Gyeomjae Jeong Seon, Sacheon Lee Byeongyeon, and Gwanajae Cho Yeongseok. The contents of this study are as follows. First, this study explored the placeness of Seochon region through the historical background like the relation between Jangdong, the clan village of Andong Kim family and Andong Kim family, and achievements of Seonwon Kim Sangyong and circumstances of that times. Second, this study tried to know original landscape of Cheongpunggye by investigating location, topography, water system etc. based on analysis of literature, old map, and paintings describing Cheongpunggye. The study was progressed in this way. To infer the original landscape, about 50 landscape elements of Cheongpunggye shown in Punggyejibseunggi(楓溪集勝記), Cheongpunggye Cheop, Cheongpunggye(淸風溪), the work of Gyeomjae Jeong Sean were searched, and then the location and form of the elements was analyzed. Furthermore, by analyzing the meanings of the names for the landscape elements, the thoughts(Naturalism, Taoism, Confucianism, Buddhism) supporting the structure of Cheongpunggye could be inferred. It is thought that these findings can contribute to exploration of placeness of Cheongpunggye. The study on original landscape of Cheongpunggye can be used as basic data when these works are executed-revival of Cheongpunggye, restoration of small streams in upper part of Cheonggyecheon, renewal of Seochon region.

• The Journal of Korean Philosophical History
• /
• no.43
• /
• pp.141-170
• /
• 2014

Science of gaining knowledge by the study of things[格物致知學]' is the translation of Science in Chosun age. Science of gaining knowledge by the study of things[格物致知學] which is the highest stage of new science is the symbol of the transfer of universal culture to the western modern civilization from old-fashioned confucianism. Modern western culture and the scientific way of thinking make man as a object to scientific research. Thinking method of social Darwinism made man believe to think like them as the modern method. And also such thinking method made man militarism and imperialism are right thinking and research methods. The core to think the science of gaining knowledge by the study of things[格 物致知學] as a violent thinking method is the Confucianism. By this method Park Eun-sik criticize this side of scientific technology as the means of militarism. Till now we pointed to think of the traditional philosophy as the tool of the western modern philosophy about war criminal. Now we rethink of the Confucianism asset as a tool of Korean Modern Culture. Musungmumul[無誠無 物] will offer moral basis to think humanism of the scientific technology of the modern western culture.