• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.343-356
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• 2016

The Korea Radioactive Waste Agency (KORAD) has developed a dual-purpose metal cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. The metal cask was designed in compliance with international and domestic technology standards, and safety was the most important consideration in developing the design. It was designed to maintain its integrity for 50 years in terms of major safety factors. The metal cask ensures the minimization of waste generated by maintenance activities during the storage period as well as the safe management of the waste. An activation evaluation of the main body, which includes internal and external components of metal casks whose design lifetime has expired, provides quantitative data on their radioactive inventory. The radioactive inventory of the main body and the components of the metal cask were calculated by applying the MCNP5 ORIGEN-2 evaluation system and by considering each component's chemical composition, neutron flux distribution, and reaction rate, as well as the duration of neutron irradiation during the storage period. The evaluation results revealed that 10 years after the end of the cask's design life, $^{60}Co$ had greater radioactivity than other nuclides among the metal materials. In the case of the neutron shield, nuclides that emit high-energy gamma rays such as $^{28}Al$ and $^{24}Na$ had greater radioactivity immediately after the design lifetime. However, their radioactivity level became negligible after six months due to their short half-life. The surface exposure dose rates of the canister and the main body of the metal cask from which the spent nuclear fuel had been removed with expiration of the design lifetime were determined to be at very low levels, and the radiation exposure doses to which radiation workers were subjected during the decommissioning process appeared to be at insignificant levels. The evaluations of this study strongly suggest that the nuclide inventory of a spent nuclear fuel metal cask can be utilized as basic data when decommissioning of a metal cask is planned, for example, for the development of a decommissioning plan, the determination of a decommissioning method, the estimation of radiation exposure to workers engaged in decommissioning operations, the management/reuse of radioactive wastes, etc.

• Journal of Astronomy and Space Sciences
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• v.26 no.1
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• pp.89-98
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• 2009

In this study, the YLPODS (Yonsei Laser-ranging Precision Orbit Determination System) is developed for POD using SLR (Satellite Laser Ranging) NP (Normal Point) observations. The performance of YLPODS is tested using SLR NP observations of TOPEX/POSEIDON and CHAMP satellite. JPL's POE (Precision Orbit Ephemeris) is assumed to be true orbit, the measurement residual RMS (Root Mean Square) and the orbit accuracy (radial, along-track, cross-track) are investigated. The validation of POD using GPS (Global Positioning System) raw data is achieved by YLPODS performance and highly accurate SLR NP observations. YGPODS (Yonsei GPS-based Precision Orbit Determination System) is used for generating GPS based precise orbits for TOPEX/POSEIDON. The initial orbit for YLPODS is derived from the YGPODS results. To validate the YGPODS results the range residual of the first adjustment of YLPODS is investigated. The YLPODS results using SLR NP observations of TOPEX/POSEIDON and CHAMP satellite show that the range residual is less than 10 cm and the orbit accuracy is about 1 m level. The validation results of the YGPODS orbits using SLR NP observations of the TOPEX/POSEIDON satellite show that the range residual is less than 10 cm. This result predicts that the accuracy of this GPS based orbits is about 1m level and it is compared with JPL's POE. Thus this result presents that the YLPODS can be used for POD validation using SLR NP observations such as STSAT-2 and KOMPSAT-5.

• Progress in Medical Physics
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• v.17 no.1
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• pp.24-31
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• 2006

Automated analysis software was developed to measure the magnitude of the intrafractional and interfractional errors during breast radiation treatments. Error analysis results are important for determining suitable planning target volumes (PTV) prior to Implementing breast-conserving 3-D conformal radiation treatment (CRT). The electrical portal imaging device (EPID) used for this study was a Portal Vision LC250 liquid-filled ionization detector (fast frame-averaging mode, 1.4 frames per second, 256X256 pixels). Twelve patients were imaged for a minimum of 7 treatment days. During each treatment day, an average of 8 to 9 images per field were acquired (dose rate of 400 MU/minute). We developed automated image analysis software to quantitatively analyze 2,931 images (encompassing 720 measurements). Standard deviations ($\sigma$) of intrafractional (breathing motion) and intefractional (setup uncertainty) errors were calculated. The PTV margin to include the clinical target volume (CTV) with 95% confidence level was calculated as $2\;(1.96\;{\sigma})$. To compensate for intra-fractional error (mainly due to breathing motion) the required PTV margin ranged from 2 mm to 4 mm. However, PTV margins compensating for intefractional error ranged from 7 mm to 31 mm. The total average error observed for 12 patients was 17 mm. The intefractional setup error ranged from 2 to 15 times larger than intrafractional errors associated with breathing motion. Prior to 3-D conformal radiation treatment or IMRT breast treatment, the magnitude of setup errors must be measured and properly incorporated into the PTV. To reduce large PTVs for breast IMRT or 3-D CRT, an image-guided system would be extremely valuable, if not required. EPID systems should incorporate automated analysis software as described in this report to process and take advantage of the large numbers of EPID images available for error analysis which will help Individual clinics arrive at an appropriate PTV for their practice. Such systems can also provide valuable patient monitoring information with minimal effort.

• 한국지구물리탐사학회:학술대회논문집
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• 2002.09a
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• pp.24-45
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• 2002

For the last several decades, high-resolution shallow marine seismic technique has been used for various resources, engineering and geological surveys. Even though the multichannel method is powerful to image subsurface structures, single channel analog survey has been more frequently employed in shallow water exploration, because it is more expedient and economical. To improve the quality of the high-resolution seismic data economically, we acquired digital seismic data using a small air gun, 6 channel streamer and PC-based system, performed data processing and produced high-resolution seismic sections. For many years, such test acquisitions were performed with other studies which have different purposes in the area of off Pohang, Yellow Sea and Gyeonggi-bay. Basic data processing was applied to the acquired data and the processing sequence included gain recovery, deconvolution, filtering, normal moveout, static corrections, CMP gathering and stacking. Examples of digitally processed sections were shown and compared with analog sections. Digital seismic sections have a much higher resolution after data processing. The results of acquisition and processing show that the high-resolution shallow marine seismic surveys using a small air gun, 6 channel streamer and PC-based system may be an effective way to image shallow subsurface structures precisely.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.333-340
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• 2010

Wastewater treatment using algal communities and biodiesel production from wastewater-cultivated algal biomass is a promising green growth technology. In literature, there are many studies providing information on algal species producing high content of lipid. However, very little is known about adaptability and wastewater treatability of such high-lipid algal species. In this study, we attempted to characterize algal biomass production and wastewater treatability of high-lipid algal species under municipal wastewater condition. For this, four known high-lipid algal strains including Chlorella vulgaris AG 10032, Ankistrodesmus gracilis SAG 278-2, Scenedesmus quadricauda, and Botryococcus braunii UTEX 572 were individually inoculated into municipal wastewater where its indigenuous algal populations were removed prior to the inoculation, and the algae-inoculated wastewater was incubated in the presence of light source (80${\mu}E$) for 9 days in laboratory batch reactors. During the incubations, algal biomass production (dry weight) and the removals of dissolved organics (COD), nitrogen and phosphorous were measured in laboratory batch reactors. According to algal growth results, C. vulgaris, A. gracilis and S. quadricauda exhibited faster growth than indigenuous wastewater algal populations while B. braunii did not. The wastewater-growing strains exhibited efficient removals of total-N, ${NH_4}^+$-N, Total-P and ${PO_4}^{3-}$-P which satisfy the Korea water quality standards for effluent from municipal wastewater treatment plants. A. gracilis and S. quadricauda exhibited efficient and stable treatability of COD but C. vulgaris showed unstable treatability. Taken together with the results, A. gracilis and S. quadricauda were found to be suitable species for biomass production and wastewater treatment under municipal wastewater condition.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.172-182
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• 2016

This study was aimed to determine the changes in vitamin $B_5$ and $B_6$ contents compared to fresh materials after parboiling treatment of the main vegetables consumed in Korea. The specificity of accuracy and precision for vitamin $B_5$ and $B_6$ analysis method were validated using high-performance liquid chromatography (HPLC). The recovery rate of standard reference material (SRM) was excellent, and all analysis was under the control line based on the quality control chart for vitamin $B_5$ and $B_6$. The Z-score for vitamin $B_6$ in food analysis performance assessment scheme (FAPAS) proficiency test was -1.0, confirming reliability of analytical performance. The vitamin $B_5$ and $B_6$ contents in a total of 39 fresh materials and parboiled samples were analyzed. The contents of vitamin $B_5$ and $B_6$ ranged from 0.000 to 2.462 and from 0.000 to $0.127mg{\cdot}100g^{-1}$, respectively. The highest contents of vitamin $B_5$ and $B_6$ were $2.462mg{\cdot}100g^{-1}$ in fresh fatsia shoots (stem vegetables), and $0.127mg{\cdot}100g^{-1}$ in fresh spinach beet (leafy vegetables), respectively. Moreover, the vitamin $B_5$ and $B_6$ contents for parboiling treatment in most vegetables were reduced or not detected. In particular, the contents of vitamin $B_5$ in parboiled fatsia shoots and vitamin $B_6$ in parboiled yellow potato and spinach beet were decreased 20- and 4-fold compared with fresh material, respectively. These results can be used as important basic data for utilization and processing of various vegetable crops, information for dietary life, management of school meals, and national health for Koreans.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.81-91
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• 2021

The Democratic People's Republic of Korea did not have direct legislation on natural environmental conservation until the early 1970s when the regime was still in the early stage. The Law on Land was enacted in 1977 to provide the legal basis for protecting the natural environment, including land protection, protection zones, and forest formation and protection. The enactment of the Law on Environmental Protection in 1986 made progress on environmental conservation in the DPRK. The constitutional amendment in 1992 stipulated "the preservation and creation of the natural environment as the responsibility of the state." Based on the Framework Law on Environmental Protection, subordinate statutes in various fields were enacted after the1990s. While the committee designated and managed the protected zones in the early days, the Framework Law on Environmental Protection established the ground for the designation of legally protected areas, and the Law on Protection of Scenic Spots and Natural Monuments enacted in 1995, and the Law on Environmental Protection enacted in 2009 provided the details. Furthermore, the types of nature reserves include biosphere reserves, primeval forest reserves, animal reserves, plant reserves, and scenic reserves. The 2nd National Biodiversity Strategy and Action Plan established in 2007 based on the Convention on Biological Diversity(CBD) stated 326 protected zones in the DPRK. However, the 2018 United Nations list of Protected Areas shows only 31 registered zones, indicating the need to establish basic information on protected areas in DPRK. This study can provide basic information for a better understanding of the nature conservation system in the DPRK. Considering that environmental protection activities such as protection of endangered species and recovery of environmental pollution are subject to exceptions under the current sanctions against North Korea (UN Security Council, the United States), it will be possible to contribute to identifying possible inter-Korean cooperation projects in the field of the natural environment.

• Korean Journal of Remote Sensing
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• v.38 no.2
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• pp.179-188
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• 2022

Global warming causes climate change and increases extreme weather events worldwide, and the occurrence of heatwaves and droughts is also increasing in Korea. For the monitoring of extreme weather, various satellite data such as LST (Land Surface Temperature), TCI (Temperature Condition Index), NDVI (Normalized Difference Vegetation Index), VCI (Vegetation Condition Index), and VHI (Vegetation Health Index) have been used. VHI, the combination of TCI and VCI, represents the vegetation stress affected by meteorological factors like precipitation and temperature and is frequently used to assess droughts under climate change. TCI and VCI require historical reference values for the LST and NDVI for each date and location. So, it is complicated to produce the VHI from the recent satellite GK2A (Geostationary Korea Multi-Purpose Satellite-2A). This study examined the retrieval of VHI using GK2A AMI (Advanced Meteorological Imager) by referencing the historical data from VIIRS (Visible Infrared Imaging Radiometer Suite) NDVI and LST as a proxy data. We found a close relationship between GK2A and VIIRS data needed for the retrieval of VHI. We produced the TCI, VCI, and VHI for GK2A during 2020-2021 at intervals of 8 days and carried out the interpretations of recent extreme weather events in Korea. GK2A VHI could express the changes in vegetation stress in 2020 due to various extreme weather events such as heatwaves (in March and June) and low temperatures (in April and July), and heavy rainfall (in August), while NOAA (National Oceanic and Atmospheric Administration) VHI could not well represent such characteristics. The GK2A VHI presented in this study can be utilized to monitor the vegetation stress due to heatwaves and droughts if the historical reference values of LST and NDVI can be adjusted in a more statistically significant way in the future work.

• Journal of Christian Education in Korea
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• v.71
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• pp.277-303
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• 2022

The COVID-19 Pandemic, which began in 2020, has led to many changes in the Korean church. It created a situation in which not only the change and form of worship time, but also the definition, direction, and philosophy of ministry had to be re-established. In the early days of COVID-19 Pandemic, the Korean church recognized this as a crisis, but gradually regarded these as opportunities and tried to produce positive results. The Department of Education has also undergone many changes, especially in its summer ministry, and is expected to have undergone more dramatic changes in form, location and method than in any other church event or service. However, no accurate data on this has been collected. Accordingly, Mirae with Dreams (CEO: Pastor Kim Eun-ho), a corporation established by the Oryun Church for the next generation of ministry, conducted a survey on the summer ministry of the Korean church, which has been registered as a future member with dreams every year since 2020 when the COVID-19 fan dummy began. A similar survey was conducted in 2022 following 2021, and 260 churches responded, and the results are as follows. In 2022, the summer ministry of the Ministry of Education of the Korean Church returned to the form before the COVID-19 Pandemic. Unlike 2021, when many of them were held online, more than 81 percent said they had conducted summer camps offline, and 31 percent also conducted or attended outdoor camps. In terms of the importance of roles, when online was also the main focus, parents and teachers were equally viewed or emphasized, while in this summer's survey, 90 percent of respondents said that the role of teachers in charge or department was important. Summer events were mainly summer Bible schools and retreats, but 25% of all respondents said they conducted missionary work and evangelism at home and abroad. Compared to 2021, participation in summer camps has increased in all departments, including infant and kindergarten, elementary and middle school, and especially in infant and middle school. While preparing for the summer camp, most of the respondents said that the focus was on content and topics, and the main focus was on children's accessibility compared to 2021. As a result of synthesizing the description of the reason for the respondents who could not conduct the summer camp, about 40% said they could not conduct the summer camp due to a lack of volunteers. This is more than 30% who pointed out COVID-19 as the cause, which can be seen as an urgent problem to be solved at the Korean church and denomination level. In addition, this paper also mentioned detailed changes in each question, referring to the changes in summer camps from 2020 to 2022.

• Journal of Korean Home Economics Education Association
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• v.33 no.4
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• pp.139-157
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• 2021

The purpose of this study is to derive implications for Korean home economics curriculum to emphasize consumer competency of adolescents by analyzing the content components of consumer competency presented in 'consumer life' area of middle school home economics curriculum of 3 states in the U.S. The analysis results and implications are summarized as follows: First, the U.S. home economics curriculum is composed of various contents, including credit management, savings/investment/ insurance, taxes, and financial situation, and financial decision-making, to improve adolescent's understanding of finance. In the next revision of Korean curriculum, for financial stability in prolonged life after retirement, it is would be necessary to include contents on basic financial knowledge and technology for financial information utilization so that students can establish financial plans for different life stages in consideration of various variables such as changes in economic environment, etc. Second, the U.S. home economics curriculum was developed to help students make better purchase decisions by applying economic concepts such as prices and interest rates, economic trends and the impact of demand and supply, purchase methods and contract conditions, etc. However, Korean home economics curriculum only focus on purchase plan and purchase decision-making process. It would be necessary to foster consumer transaction competency by introducing economic concepts suitable middle school level. Third, to emphasize "consumer civic competency", Ohio was focusing on "claim of consumer rights" and Wisconsin was focusing on the "acceptance of consumer responsibility." In order to enhance adolescent's consumer civic competency, it would be necessary for Korean curriculum to balance the claim of right and the acceptance of consumer responsibility in the following term, and to emphasize the contents on consumer policies, laws and consumer advocacy to create a consumer environment where consumer sovereignty is realized.