• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.387-393
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• 2021

In this study, finite element analysis was performed to evaluate a method of increasing the fatigue life of the pipe connection structure commonly used in the topside structure of offshore platforms. MSC Patran/Nastran, a commercial analysis program, was used, and the critical structural model was selected from the global analysis. To realize the stress concentration phenomenon according to the load, modeling using 8-node solid elements was implemented. The main loads were considered to be two lateral loads and a tensile load on a diagonal pipe. To check the hotspot stress at the main location, a 0.01 mm dummy shell element was applied. After calculating the main stress at the 0.5-t and 1.5-t locations, the stress generated in the weld was estimated through extrapolation. In some sections, this stress was observed to be below the fatigue life that should be satisfied, and reinforcement was required. For reinforcement, a bracket was added to reduce the stress concentration factor where the fatigue life was insufficient without changing the thickness or diameter of the previously designed pipe. Regarding the tensile load, the stress in the bracket toe increased by 23 %, whereas the stress inside and outside of the pipe, which was a problem, decreased by approximately 8 %. Regarding the flexural load, the stress at the bracket toe increased by 3 %, whereas the stress inside and outside of the pipe, which was also a problem, decreased by approximately 48 %. Owing to the new bracket reinforcement, the stress in the bracket toe increased, but the S-N curve itself was better than that of the pipe joint, so it was not a significant problem. The improvement method of fatigue life is expected to be useful; it can efficiently increase the fatigue life while minimizing changes to the initial design.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1773-1784
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• 2021

In order to minimize damage to oil spill accidents in the ocean, it is essential to collect a spilled area as soon as possible. Thus satellite-based remote sensing is a powerful source to detect oil spills in the ocean. With the recent rapid increase in the number of available satellites, it has become possible to generate a status report of marine oil spills soon after the accident. In this study, the oil spill area was calculated using various satellite images for the Symphony oil spill accident that occurred off the coast of Qingdao Port, China, on April 27, 2021. In particular, improving the accuracy of oil spill area determination was applied using high-resolution commercial satellite images with a spatial resolution of 2m. Sentinel-1, Sentinel-2, LANDSAT-8, GEO-KOMPSAT-2B (GOCI-II) and Skysat satellite images were collected from April 27 to May 13, but five images were available considering the weather conditions. The spilled oil had spread northeastward, bound for coastal region of China. This trend was confirmed in the Skysat image and also similar to the movement prediction of oil particles from the accident location. From this result, the look-alike patch observed in the north area from the Sentinel-1A (2021.05.01) image was discriminated as a false alarm. Through the survey period, the spilled oil area tends to increase linearly after the accident. This study showed that high-resolution optical satellites can be used to calculate more accurately the distribution area of spilled oil and contribute to establishing efficient response strategies for oil spill accidents.

• Journal of Korea Water Resources Association
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• v.54 no.7
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• pp.535-544
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• 2021

Agricultural water occupies 48% of water demand, and management of agricultural reservoirs is essential for water resources management within agricultural basins. For more efficient use of agricultural water, monitoring the distribution of water resources in agricultural reservoirs and agricultural basins is required. Therefore, in this study, three threshold determination methods (i.e., fixed threshold, Otsu threshold, Kittler-Illingworth (KI) threshold) were compared to detect terrestrial water bodies using Sentinel-1 images for 3 years from 2018 to 2020. The purpose of this study was to evaluate methods for determining threshold values to more accurately estimate the reservoir area. In addition, by analyzing the relationship between the water surface and water storage at the Edong, Gosam, and Giheung reservoirs, water storage based on the SAR image was estimated and validated with observations. The thresholding method for detecting a waterbody was found to be the most accurate in the case of the KI threshold, and the water storage estimated by the KI threshold indicated a very high agreement (r = 0.9235, KGE' = 0.8691). Although the seasonal error characteristics were not observed, the problem of underestimation at high water levels may occur; the relationship between the water surface and the water storage could change rapidly. Therefore, it is necessary to understand the relationship between the water surface area and water storage through ground observation data for a more accurate estimation of water storage. If the use of SAR data through water resources satellites becomes possible in the future, based on the results of this study, it is judged that it will be beneficial for monitoring water storage and managing drought.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.268-276
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• 2018

BACKGROUND: In the month of January 2018, fine dust alerts and warnings were issued 36 times for $PM_{10}$ and 81 times for PM2.5. Air quality is becoming a serious issue nation-wide. Although interest in air-purifying plants is growing due to the controversy over the risk of chemical substances of regular air-purifying solutions, industrial spread of the plants has been limited due to their efficiency in air-conditioning perspective. METHODS AND RESULTS: This study aims to propose a vegetation-based bio-filter system that can assure total indoor air volume for the efficient application of air-purifying plants. In order to evaluate the quantitative performance of the system, time-series analysis was conducted on air-conditioning performance, indoor air quality, and comfort index improvement effects in a lecture room-style laboratory with 16 persons present in the room. The system provided 4.24 ACH ventilation rate and reduced indoor temperature by $1.6^{\circ}C$ and black bulb temperature by $1.0^{\circ}C$. Relative humidity increased by 24.4% and deteriorated comfort index. However, this seemed to be offset by turbulent flow created from the operation of air blowers. While $PM_{10}$ was reduced by 39.5% to $22.11{\mu}g/m^3$, $CO_2$ increased up to 1,329ppm. It is interpreted that released $CO_2$ could not be processed because light compensation point was not reached. As for the indoor comfort index, PMV was reduced by 83.6 % and PPD was reduced by 47.0% on average, indicating that indoor space in a comfort range could be created by operating vegetation-based bio-filters. CONCLUSION: The study confirmed that the vegetation-based bio-filter system is effective in lowering indoor temperature and $PM_{10}$ and has positive effects on creating comfortable indoor space in terms of PMV and PPD.

• The Korean Journal of Archival Studies
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• no.19
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• pp.153-192
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• 2009

Appearing newly on June 1894, Gaboh regime enforced modern reformation policy. In light of archives' management, it was totally different from before. Government established individual department of record management in every division and proclaimed a legislative bill which was stipulated about record management process. They modified archives' form including peculiar declaration of the name of an era and use together with Korean and Chinese. Also they tried to conserve the original copy of the archives. As King Gojong announced the Great Han Empire(Taehan Cheguk, 大韓帝國) on October 1897, he reinforced Gaboh regimes' weakened royal authority and enforced reformation policy which was designed for himself. First he abolished the administration which restricted royal authority, and established new department called Euijungbu(議政府). To restrain the royal power, he separated the Royal House and government and reinforced Gungnaebu(宮內府). In addition, King Gojong enforced the policy which he can manage directly about troops, policies, and finances. Consequently, He established Wonsubu(元帥府), Kyungbu(警部), and made direct belonging of an emperor. Also, department called Naejangwon(內藏院) tried to levy many kinds of taxes directly to build up the financial foundation under the emperor. The record management system of Great Han Empire succeeded to that of Gaboh regimes Times'. First, government and powerful organization directly under the emperor set up the department of record management. Euijungbu (議政府) and governmental department, of course, Gungnaebu(宮內府), Wonsubu(元帥府), Kyungbu(警部), Tongshinwon(通信院), Jikyeahmun(地契衙門) which support the right of an emperor established document division and record division individually. To carry out government's service effectively and systematically, it was considered effective to divide record management department. Moreover, despite the difference between the divisions, they were separated into current record division and non current record division. Generally, document department took charge of acceptance, sending and crafting of current document and archives department was eligible for preservation and compilation of major document and eternal conservation document. This seems to consider life cycle of the record and keep the evaluation of record in mind. Finally, perception for the record management has revealed to modern configuration.

• Journal of Climate Change Research
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• v.5 no.2
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• pp.95-107
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• 2014

The 'Green Start Movement' is a practical movement of green living to efficiently reduce the greenhouse gases originating from non-industrial fields such as household, commerce, transportation, etc. for the 'materialization of a low carbon society through green growth (Low Carbon, Green Korea)'. When the new government took office, following the Lee Myeongbak Administration that had presented 'Low Carbon, Green Growth' as a national vision, it was required to set up the direction of the practical movement of green life to respond to climate change persistently and stably as well as to evaluate the performance of the green start movement over the past 5 years. A questionnaire survey was administered to a total of 265 persons including public servants, members of environmental and non-environmental NGOs, participants of the green start movement and professionals. In the results of the questionnaire survey, many opinions have indicated that the awareness of the green start movement is increasing and the green start movement has had a positive impact on individual behavior and group behavior in terms of green living. The result shows, however, that the environmental NGOs don't cooperate sufficiently to create a 'green living' effect on a national scale. Action needs to be taken on the community level in order to generate a culture of environmental responsibility. The national administration office of the Green Start Movement Network should play the leading role between the government and environmental NGOs. The Green Start National Network should have greater autonomy and governance of the network needs to be restructured in order to work effectively. Also the Green Start Movement should identify specific local characteristics to support activities that reduce greenhouse gas emissions. Best practices can be shared to reduce greenhouse gas emissions by a substantial amount.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.59-63
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• 2019

Purpose The motion due to respiration of patients undergoing PET/CT is a cause of artifacts in image and registration error between PET and CT images. The degree of displacement and distortion for tumor, which affects the measurement of Standard Uptake Value (SUV) and lesion volume, is especially higher for tumors that is small or located at the base of lungs. The purpose of this study was to evaluate the usefulness of prone position in the correction of image distortion due to respiration of patients in PET/CT. Materials and Methods The imaging equipment used in this study was PET/CT Discovery 600 (GE Healthcare, MI, USA). 20 patients whose lesions were identified in the middle and lower lungs from May to August 2018 were enrolled in this study. After acquiring whole body image in the supine position, additional images of the lesion area were obtained in the prone position with the same conditions. SUVmax, SUVmean, and volume of the lesion were measured for each image, and the displacement of the lesion on PET and CT images were measured, compared, and analyzed. Results The SUVmax, SUVmean, and volume, and displacement of the lesion were $4.72{\pm}2.04$, $3.10{\pm}1.38$, $4.68{\pm}3.20$, and $4.64{\pm}1.88$, respectively for image acquired in the supine position and $5.89{\pm}2.42$, $3.97{\pm}1.65$, $2.13{\pm}1.09$, and $2.24{\pm}0.84$, respectively for image acquired in the prone position, indicating that, for all the lesions imaged, SUVmax and SUVmean were higher and volume and displacement were smaller in the images acquired in prone position compared to those acquired in supine one(p<0.05). Conclusion These results showed that the prone position PET/CT imaging improves the quality of the image by increasing the SUV of the lesion and reducing the respiratory artifacts caused by registration error between PET and CT images. It is considered that the PET/CT imaging in the prone position is helpful in the diagnosis of the disease as an economical and efficient methods that correct registration error for the lesions in basal lung and reduce artifacts.

• Korean Journal of Heritage: History & Science
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• v.37
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• pp.405-444
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• 2004

The Cultural Heritage Committee is an advisory committee established under the Cultural Heritage Administration with the aim of carrying out examination and deliberation on preservation, management and use of cultural heritage. The Cultural Heritage Administration is the highest administrative organization in terms of Korean cultural heritage. It was founded to produce and execute policies on cultural heritage, an important task that requires a high level of specialized knowledge, skills and academic expertise. It involves in-depth investigation and consultation of experts in the field of cultural heritage. An organization consisting of distinguished experts, the Cultural Heritage Committee plays an important role in policymaking on cultural heritage of Korea. The Korean government established the Bureau of Cultural Heritage in October 1961, and enacted provisions (as a presidential decree) on the organization on March 27, 1962, according to the Cultural Heritage Act established on January 10 of the same year. The Cultural Heritage Committee was opened as a deliberation committee according to the law, on which currently 90 members serve in 8 subcommittees. The term of office of a committees member is two years. The deliberation of the committee, which covers the entire range of cultural heritage, including their designation and cancellation, is normally concluded by the deliberation and decision of each subcommittee. This study aims to analyze of the survey of the Cultural Heritage Committee as the highest organ for the deliberation of policies on the matters of cultural heritage. The subject of the analysis in this study is a questionnaire survey that was conducted between Oct. 20 and Nov. 29, 2003, of 116 former and current members of the committee.

• Korean Journal of Heritage: History & Science
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• v.52 no.2
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• pp.38-61
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• 2019

Up until the early twentieth century in Germany, there were two research trends: 1) emphasizing objectives and making detailed observations of archaeological artifacts and sites, 2) tracing the remains of specific nations or ethnic groups and defining their temporal-spatial boundaries by conducting research on material culture in terms of nationalism or ethnocentrism. After the Second World War ended and Germany was divided, West German archaeology focused on observations of artifacts and sites, cataloging them, and doing research on chronology and distribution following their own traditional methodologies. East German archaeology attempted to prove the developing process of history and its Marxist principles based upon material culture and to examine the historic value of inherent specific cultural heritage based on criteria regarding how it corresponded to socialism and contributed to the development of socialism. Nevertheless, East and West German archaeology shared traditional archaeological methods inherited from German archaeology since the nineteenth century, and contact between archaeologists in West and East Germany continued to a degree. Furthermore, East German archaeology produced significant archaeological achievements acknowledged by West German and European archaeologists. These facts provided the momentum to complete rapid incorporation of the archaeologies of West and East Germany in spite of a one-sided process imposed by West German archaeology. In the case of Korea, it seems necessary to make an effort to share common research history and traditions and to encourage mutual academic exchange (e.g. joint excavation and archaeological research). Furthermore, it is also imperative to have open-minded attitudes toward accepting substantial results and interpretations achieved by North Korean archaeologists under scrutiny when and where necessary, despite seeming to have been fossilized by Marxism and Juche ideology. Any efforts to narrow the gap in archaeological research and conservation of cultural heritage between the archaeologies of South and North Korea should be made immediately. The case of Germany demonstrates how such a project could proceed efficaciously.

• The Korean Journal of Archival Studies
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• no.34
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• pp.221-250
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• 2012

This paper introduces the characteristics of the records and archives management of Korea from Joseon dynasty to now. This paper also explains historical background of making the records and archives management in Joseon dynasty. This paper introduces the process of establishment of modern records management system by adopting records management system and public administration of USA after liberation in 1945. The Joseon bureaucrats established systematic methodologies for managing and arranging the records. Jeseon dynasty managed its records systematically since it was a bureaucratic regime. It is also noticeable that the famous Joseonwangjosilrok(Annals of Joseon dynasty) came out of the power struggles for the control of the national affairs between the king and the nobility during the time of establishment of the dynasty. Another noticeable feature of the records tradition in Joseon dynasty was that the nobility recorded their experience and allowed future generations use and refer their experiences and examples when they performed similar business. The records of Joseon period are the historical records which recorded contemporary incidents and the compilers expected the future historians evaluate the incidents they recorded. In 1894, the reformation policy of Gaboh governments changed society into modernity. The policy of Gaboh governments prescribed archive management process through 'Regulation(命令頒布式)'. They revised the form of official documents entirely. They changed a name of an era from Chinese to unique style of Korean, and changed original Chinese into Korean or Korean-Chinese together. Also, instead of a blank sheet of paper they used printed paper to print the name of each office. Korea was liberated from Japanese Imperialism in 1945 and the government of Republic of Korea was established in 1948. In 1950s Republic of Korea used the records management system of the Government-General of Joseon without any alteration. In the late of 1950's Republic of Korea constructed the new records management system by adopting records management system and public administration of USA. However, understanding of records management was scarce, so records and archives management was not accomplished. Consequently, many important records like presidential archives were deserted or destroyed. A period that made the biggest difference on National Records Management System was from 1999 when was enacted. Especially, it was the period of President Roh's five-year tenure called Participation Government (2003-2008). The first distinctive characteristic of Participation Government's records management is that it implemented governance actively. Another remarkable feature is a nomination of records management specialists at public institutions. The Participation Government also legislated (completely revised) . It led to a beginning of developing records management in Republic of Korea.