• Korean Journal of Remote Sensing
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• v.41 no.6
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• pp.1251-1258
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• 2025

This study presents a prototype harmonized surface reflectance dataset generated by integrating PlanetScope (SuperDove) and Sentinel-2 (MSI) imagery following the NASA-ESA Harmonized Landsat-Sentinel-2 (HLS) framework. Atmospheric correction of PlanetScope imagery using the Land Surface Reflectance Code (LaSRC) algorithm effectively reduced scene-to-scene variability and improved aerosol retrieval, resulting in more stable surface reflectance. PlanetScope reflectance was then normalized to the HLS standard, yielding substantial improvements in radiometric consistency, with regression slopes approaching one and coefficients of determination (R²) increasing to 0.91-0.93 for the Red and Near-Infrared (NIR) bands. Time-series evaluation using Normalized Difference Vegetation Index (NDVI) demonstrated that the harmonized PlanetScope NDVI closely reproduced the phenological trajectory observed in HLS, confirming the potential of high-resolution, high-frequency imagery for agricultural monitoring. The findings provide an important technical foundation for applying similar harmonization strategies to the upcoming Korean agricultural satellite, the Compact Advanced Satellite 500-4 (CAS500-4). Further research is required to expand validation across seasons, crop types, and diverse observation conditions. In addition, the prototype results suggest that the integration of satellite data can substantially enhance temporal continuity during cloud-affected seasons. These outcomes highlight the need to expand validation across broader spatial domains and crop systems to further generalize the harmonization framework.

• Nuclear Engineering and Technology
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• v.57 no.9
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• pp.103646.1-103646.13
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• 2025

Recently, a pre-conceptual design study was conducted in Korea for developing a dedicated linear accelerator (linac) for 400 kW (40 MeV, maximum 10 mA CW) deuteron (D⁺) beams to generate fusion-like neutrons. The accelerated beam hits a solid Beryllium target to produce fusion-like neutrons, which will be utilized for technical feasibility tests of the breeding blanket including tritium production and recovery. In this work, we present detailed start-to-end simulation and machine imperfection studies with proper beam tuning to assess the target beam availability and validate the machine specifications. We have designed a 2.45 GHz ECR ion source and a 4-vane type 176 MHz RFQ by using IBSimu, Parmteq, and Toutatis simulation codes. We propose a super-conducting linac with HWR cavities and solenoid-focusing magnets to accelerate the beam up to 40 MeV. In the HEBT line, we adopt two octupole magnets and subsequent quadrupole magnets to make a rectangular-shaped and uniform density beam with 20 cm × 20 cm footprint at the target. Extensive beam dynamics studies along the linac have been performed using the TraceWin simulation code.

• Journal of Technology Innovation
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• v.33 no.2
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• pp.41-66
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• 2025

This study aims to identify the technological evolution and core technology domains of HVDC (High Voltage Direct Current), a new growth engine in the Korean power industry. This is achieved through a patent-based bibliometric analysis rather than a traditional technical perspective. By collecting domestic and international HVDC-related patent data, the study applied keyword network analysis and IPC code analysis to derive the structural composition and key concepts of HVDC technology. As a result, 'Voltage', 'System', 'Converter', and 'Control' were identified as the primary technological domains. In particular, IPC trend analysis revealed the recent emergence of intelligent systems focused on protection and control, indicating that HVDC technology is evolving from traditional transmission systems to integrated and digitally based platforms. This study is expected to serve as foundational data for establishing domestic HVDC R&D directions and strategies to enhance global technological competitiveness.

• Communications of Mathematical Education
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• v.40 no.1
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• pp.193-215
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• 2026

In the elementary mathematics textbooks aligned with the 2022 revised curriculum, QR codes have been widely introduced as one of the means to facilitate access to a variety of digital learning resources. However, systematic analyses of the types of materials and instructional functions associated with QR codes in elementary mathematics textbooks remain limited. To address this gap, this study analyzed nine elementary mathematics textbook series for Grades Three and Four developed under the Korea's 2022 revised national curriculum. The analysis examined the distribution of QR codes across textbooks and content domains, the types of materials provided through QR codes, and their instructional uses. The results revealed substantial differences among textbooks not only in the quantity of QR codes but also in the types of content and patterns of use. These findings suggest that guidelines for QR code implementation should move beyond formal or technical considerations to incorporate the pedagogical characteristics of the linked materials. Based on these findings, this study discusses specific implications for the design and development of QR codes in elementary mathematics textbooks.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.4
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• pp.375-387
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• 2019

In this study, the radiation dose rates for the design basis fuel of 360 assemblies CANDU spent nuclear fuel transportation cask were evaluated, by measuring radiation source terms for the design basis fuel of a pressurized heavy water reactor. Additionally, radiological safety evaluation was carried out and the validity of the results was determined by radiological technical standards. To select the design basis fuel, which was the radiation source term for the spent fuel transportation cask, the design basis fuels from two spent fuel storage facilities were stored in a spent fuel transportation cask operating in Wolsung NPP. The design basis fuel for each transportation and storage system was based on the burnup of spent fuel, minimum cooling period, and time of transportation to the intermediate storage facility. A burnup of 7,800 MWD/MTU and a minimum cooling period of 6 years were set as the design basis fuel. The radiation source terms of the design basis fuel were evaluated using the ORIGEN-ARP computer module of SCALE computer code. The radiation shielding of the cask was evaluated using the MCNP6 computer code. In addition, the evaluation of the radiation dose rate outside the transport cask required by the technical standard was classified into normal and accident conditions. Thus, the maximum radiation dose rates calculated at the surface of the cask and at a point 2 m from the surface of the cask under normal transportation conditions were respectively 0.330 mSv·h^-1 and 0.065 mSv·h^-1. The maximum radiation dose rate 1 m from the surface of the cask under accident conditions was calculated as 0.321 mSv·h^-1. Thus, it was confirmed that the spent fuel cask of the large capacity heavy water reactor had secured the radiation safety.

• Journal of Radiation Protection and Research
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• v.40 no.4
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• pp.252-260
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• 2015

This paper describes the technical background for the Korean wildlife radiation dose assessment code, K-BIOTA, and the summary of its application. The K-BIOTA applies the graded approaches of 3 levels including the screening assessment (Level 1 & 2), and the detailed assessment based on the site specific data (Level 3). The screening level assessment is a preliminary step to determine whether the detailed assessment is needed, and calculates the dose rate for the grouped organisms, rather than an individual biota. In the Level 1 assessment, the risk quotient (RQ) is calculated by comparing the actual media concentration with the environmental media concentration limit (EMCL) derived from a bench-mark screening reference dose rate. If RQ for the Level 1 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 2 assessment, which calculates RQ using the average value of the concentration ratio (CR) and equilibrium distribution coefficient (Kd) for the grouped organisms, is carried out for the more realistic assessment. Thus, the Level 2 assessment is less conservative than the Level 1 assessment. If RQ for the Level 2 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 3 assessment is performed for the detailed assessment. In the Level 3 assessment, the radiation dose for the representative organism of a site is calculated by using the site specific data of occupancy factor, CR and Kd. In addition, the K-BIOTA allows the uncertainty analysis of the dose rate on CR, Kd and environmental medium concentration among input parameters optionally in the Level 3 assessment. The four probability density functions of normal, lognormal, uniform and exponential distribution can be applied.The applicability of the code was tested through the participation of IAEA EMRAS II (Environmental Modeling for Radiation Safety) for the comparison study of environmental models comparison, and as the result, it was proved that the K-BIOTA would be very useful to assess the radiation risk of the wildlife living in the various contaminated environment.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.319-326
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• 2009

Two parallel wide flange built-up beams are widely used as struts in resisting lateral earth pressure because of the effectiveness in structure and construction. In a certain structural system, the reinforced concrete columns are to be placed at the intersection where two perpendicular beams cross each other, the square part of the joint being filled with concrete. In the punching shear mechanism of the beam-column joint, the radial deformation caused due to shear cracking will be constrained by the spring action of the squarely encompassed beam flanges. As a result, the punching shear strength of the joint concrete can be expected to be increased. To verify this phenomenon experiments have been performed for various constraining elements and distances between columns and constraints. Test results are compared with the approximation analysis formula which has been proposed in this study, based on the code formula. The results calculated by the proposed equation show comparatively close agreement with the punching shear strength detected from the test.

• Management & Information Systems Review
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• v.33 no.2
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• pp.101-118
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• 2014

In the mid-2000s, Web 2.0 appears and is becoming a general cultural code with the keyword of participation, sharing, and openness. Web 2.0, in which consumption is being transformed by the participatory web culture, has evolved. However, associated with the evolution of Web 2.0, several significant concerns appears in a society. Among them, this study will focuses on the cyber-ethics issues. There are limitations to solve the cyber-ethics problems only in the technical and legal approaches. Therefore, the current article intends to consider comprehensively the antecedents of cyber-ethics such as individual characteristics, social influence, and cultural characteristics. Specifically, (1) Do individual characteristics(i.e., self-efficacy, locus of control) affect cyber-ethics in the Web 2.0 environment?, (2) Do social influence(i.e., subjective norm) have an effect on cyber-ethics?, (3) Do cyber -ethics have an impact on user participation in the Web 2.0 services(i.e., retrieval and creation)?, finally (4) Do international cultural difference have a moderation effect on the relationship between cyber-ethics and user participation? For testing empirically the hypothesized research model, this study collected questionnaires in South Korea as well as U.S.A. The results showed that individual characteristics and social influence affect cyber-ethics toward user's creative activities in Web 2.0 sites.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8128-8139
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• 2015

Recently, the necessity of developing the load and resistance factor design(LRFD) for soft ground improvement method has been raised, since the limit state design is requested as international technical standard for the foundation of structures. In this study, to develop LRFD codes for foundation structures in Korea, target reliability index and resistance factor for static bearing capacity of driven steel pipe piles were calibrated in the framework of reliability theory. The 16 data(in Gwangyang) and the 57 data(Korea Institute of Construction Technology, 2008) sets of static load test and soil property tests conducted in the whole domestic area were collected along with available subsurface investigation results. The resistance bias factors were evaluated for the tow static design methods by comparing the representative measured bearing capacities with the expected design values. Reliability analysis was performed by two types of advanced methods : the First Order Reliability Method (FORM), and the Monte Carlo Simulation (MCS) method using resistance bias factor statistics. As a result, when target reliability indices of the driven pipe pile were selected as 2.0, 2.33, 2.5, resistance factor of two design methods for SPT N at pile tip less than 50 were evaluated as 0.611~0.684, 0.537~0.821 respectively, and STP N at pile tip more than 50 were evaluated as 0.545~0.608, 0.643~0.749 respectively. The result from this research will be useful for developing various foundations and soil structures under LRFD.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.8
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• pp.611-620
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• 2018

For the past decades, the analytic model for distributed surface roughness has been developed to improve the accuracy of the icing simulation code. However, it remains limitations to validate the developed model and determine the empirical parameters due to the absence of the quantitative experimental data which were focused on the surface state. To this end, the experimental study conducted to analyze the ice covered surface state from a micro-perspective. Above all, the tendency of the smooth zone width which occurs near the stagnation point has been quantitatively analyzed. It is observed that the smooth zone width is increased as growing the ambient temperature and freestream velocity. Next, the characteristics of the ice covered surface under rime and glaze ice have been analyzed. For rime ice conditions, ice elements are developed as the opaque circular corn in the opposite direction of freestream. The height and interval of each circular corn are increased as rising the ambient temperature. For glaze ice conditions, numerous lumps of translucent ice can be observed. This is because the beads formed by gravity concentrate and froze on the lower surface.