• KIPS Transactions on Computer and Communication Systems
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• 제12권10호
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• pp.309-318
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• 2023

Recently, each country has been moving to introduce an LCA (Life Cycle Assessment) to regulate greenhouse gas emissions. The LCA is a mean of measuring and evaluating greenhouse gas emissions generated over the entire life cycle of a vehicle. Reliable data for each electric vehicle component is needed to increase the reliability of the LCA results. To this end, studies on life cycle evaluation models using blockchain technology have been conducted. However, in the existing model, key product information is exposed to other participants. And each time parts data information is updated, it must be recorded in the blockchain ledger in the form of a transaction, which is inefficient. In this paper, we proposed a DID(Decentralized Identity)-based data collection model for LCA to collect vehicle component data and verify its validity effectively. The proposed model increases the reliability of the LCA by ensuring the validity and integrity of the collected data and verifying the source of the data. The proposed model guarantees the validity and integrity of collected data. As only user authentication information is shared on the blockchain ledger, the model prevents indiscriminate exposure of data and efficiently verifies and updates the source of data.

• Proceedings of the Plant Resources Society of Korea Conference
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.68-68
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• 2020

최근 농촌진흥청과 기상청에서 발표한 연구자료에 따르면 2020년 기준으로 국내 경지면적의 10% 가량이 이미 아열대 기후대에 속하고 있을 뿐 현재 추세대로 온실가스가 배출될 경우 2100년경 우리나라의 대부분 지역은 아열대 기후대에 속하게 될 것으로 전망되고 있다. 이에 국가 기관뿐만 아니라 많은 지자체에서 기후변화에 대응하여 아열대 작물을 도입하기 위한 시도를 활발하게 추진하고 있다. 아열대 작물 중 국내에서 3번째로 많이 활용되고 있는 삼채는 기능성 물질을 다량으로 함유하고 있어 수요도가 지속적으로 증가하고 있다. 하지만, 삼채의 경우 일반적인 원예 작물과는 달리 실생 종자를 상업적으로 이용하고 있어 종자들의 발아율이 균일하지 못할 뿐만 아니라 발아율이 낮은 문제가 있는 것으로 보고되고 있다. 이에 삼채의 경우 농가에서 정식 시기를 맞추기 어려울 뿐만 아니라 대규모 생산을 위한 공정육묘 시스템의 적용이 어려운 상황에 있다. 종자 프라이밍 기술은 잠재적으로 종자 발아와 식물 생장을 빠르고 균일하게 해줄 수 있는 방법으로 알려져 있지만, 현재 삼채에서는 프라이밍 처리가 종자 발아에 미치는 영향에 대해서 검토한 사례가 없다. 따라서 본 연구는 삼채의 파종 효율을 증진시키기 위한 목적으로 몇 가지 프라이밍 처리 방법이 삼채의 발아특성에 미치는 영향을 검정하고자 하였다. 삼채 종자는 (주)아람종묘사의 종자를 구매하여 강릉원주대학교 생명과학대학에서 수행하였다. 프라이밍 처리는 Hydropriming은 증류수, Osmopriming은 CaCl2 1.0%, Halopriming은 Polyrthylene glycol 6000(PEG) 13.5%의 3가지를 사용하였으며, 각 프라이밍 처리 시간은 6시간, 12시간, 18시간, 24시간, 48시간 총 5가지 방법으로 처리되어 대조구를 포함 총 16개의 처리를 하였다. 프라이밍 처리 된 종자는 페트리디쉬 (50mm)에 30립씩 치상하였다. 프라이밍 각 처리구별 4반복으로 하였으며 24시간 암(Black), 온도 20℃의 조직배양실에서 치상 후 10일간 조사하였다. 본 실험 결과 대조구는 38% 발아율을 가졌으며, 프라이밍 처리 시간에 따른 각 처리구들은 대조구에 비해 발아율이 높아짐을 확인할 수 있었다. 그 중 Hydropriming 12시간 발아율 51%, Osmopriming 18시간 발아율 68%, Halopriming 48시간 발아율 65%로 각 프라이밍 처리구별 가장 좋은 발아율을 확인할 수 있었다. 결론적으로 삼채에서 프라이밍 처리 기술의 적용은 발아율의 향상과 발아기간의 정형화를 유도할 수 있어 농가에서의 일반 육묘는 물론이고 대규모 공정육묘를 위한 저렴하고 안전한 방법 중 하나로써 이용될 수 있을 것으로 기대되어 진다.

• Korea Trade Review
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• 제48권2호
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• pp.111-127
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• 2023

While the e-commerce market in Southeast Asia is growing, this study aims to derive factors for establishing an entry strategy for the Cambodian e-commerce market where Korean logistics companies can strategically enter in the future. Cambodia is a country where growth and growth potential in the e-commerce market is steadily increasing based on the high youth population ratio, high smartphone penetration rate, the introduction of convenient payment systems, and government-level e-commerce promotion policies. In this study, Korean logistics companies established detailed promotion strategies by deriving factors necessary for Cambodia's entry into the e-commerce market and analyzing their relative importance. The AHP analysis technique derived three top factors for the entry strategy, and each presented four sub-factors. As a result, the importance was shown in the order of 'Market Factor' (0.556), 'Policy and Institutional Factor' (0.295), and 'Corporate Competency Factor' (0.149). As a result of the sub-factors analysis, the importance was found in the order of "Characteristics and Growth Potential of Distribution Channel" (0.230), "Purchasing Power and Awareness Level of Consumers" (0.176), "Cambodia Government's E-commerce Policy and Institutional Support" (0.122), and "Cambodia Government's Logistics Infrastructure Plan" (0.108). In both the upper and lower factors, the characteristics and growth potential of the Cambodian e-commerce market were important, indicating that Korean logistics companies value market size and growth potential to enter the Cambodian e-commerce market. The results of this study can be used as a guideline to help Korean logistics companies make successful inroads into Cambodia, where the e-commerce market is expected to grow in the future.

• Journal of Internet Computing and Services
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• 제24권6호
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• pp.73-80
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• 2023

The recent steep increase in the minimum hourly wage has increased the burden of labor costs, and the share of unmanned stores is increasing in the aftermath of COVID-19. As a result, theft crimes targeting unmanned stores are also increasing, and the "Just Walk Out" system is introduced to prevent such thefts, and LiDAR sensors, weight sensors, etc. are used or manually checked through continuous CCTV monitoring. However, the more expensive sensors are used, the higher the initial cost of operating the store and the higher the cost in many ways, and CCTV verification is difficult for managers to monitor around the clock and is limited in use. In this paper, we would like to propose an AI image processing fusion algorithm that can solve these sensors or human-dependent parts and detect customers who perform abnormal behaviors such as theft at low costs that can be used in unmanned stores and provide cloud-based notifications. In addition, this paper verifies the accuracy of each algorithm based on behavior pattern data collected from unmanned stores through motion capture using mediapipe, object detection using YOLO, and fusion algorithm and proves the performance of the convergence algorithm through various scenario designs.

• Korean Journal of Remote Sensing
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• 제39권6_2호
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• pp.1541-1551
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• 2023

Radiometric calibration is a fundamental step in ocean color remote sensing since the step to derive solar radiance spectrum in visible to near-infrared wavelengths from the sensor-observed electromagnetic signals. Generally, satellite sensor suffers from degradation over the mission period, which results in biases/uncertainties in radiometric calibration and the final ocean products such as water-leaving radiance, chlorophyll-a concentration, and colored dissolved organic matter. Therefore, the importance of radiometric calibration for the continuity of ocean color satellites has been emphasized internationally. This study introduces an approach to improve the radiometric calibration algorithm for the visible bands of the Geostationary Ocean Color Imager-II (GOCI-II) satellite with a focus on stability. Solar Diffuser (SD) measurements were employed as an on-orbit radiometric calibration reference, to obtain the continuous monitoring of absolute gain values. Time series analysis of GOCI-II absolute gains revealed seasonal variations depending on the azimuth angle, as well as long-term trends by possible sensor degradation effects. To resolve the complexities in gain variability, an azimuth angle correction model was developed to eliminate seasonal periodicity, and a sensor degradation correction model was applied to estimate nonlinear trends in the absolute gain parameters. The results demonstrate the effects of the azimuth angle correction and sensor degradation correction model on the spectrum of Top of Atmosphere (TOA) radiance, confirming the capability for improving the long-term stability of GOCI-II data.

• Journal of Korea Water Resources Association
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• 제56권12호
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• pp.969-980
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• 2023

Since the 2000s, ensemble streamflow prediction (ESP) has been actively utilized in South Korea, primarily for hydrological forecasting purposes. Despite its notable success in hydrological forecasting, the original objective of enhancing water resources system management has been relatively overlooked. Consequently, this study aims to demonstrate the utility of ESP in water resources management by creating a simple hypothetical exercise for dam operators and applying it to actual multi-purpose dams in South Korea. The hypothetical exercise showed that even when the means of ESP are identical, different costs can result from varying standard deviations. Subsequently, using sampling stochastic dynamic programming (SSDP) and considering the capacity-inflow ratio (CIR), optimal release patterns were derived for Soyang Dam (CIR = 1.345) and Chungju Dam (CIR = 0.563) based on types W and P. For this analysis, Type W was defined with standard deviation equal to the mean inflow, and Type P with standard deviation ten times of the mean inflow. Simulated operations were conducted from 2020 to 2022 using the derived optimal releases. The results indicate that in the case of Dam Chungju, more aggressive optimal release patterns were derived under types with smaller standard deviations, and the simulated operations demonstrated satisfactory outcomes. Similarly, Soyang Dam exhibited similar results in terms of optimal release, but there was no significant difference in the simulation between types W and P due to its large CIR. Ultimately, this study highlights that even with the same mean values, the standard deviation of ESP impacts optimal release patterns and outcomes in simulation. Additionally, it underscores that systems with smaller CIRs are more sensitive to such uncertainties. Based on these findings, there is potential for improvements in South Korea's current operational practices, which rely solely on single representative values for water resources management.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• 제17권1호
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• pp.1-12
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• 2022

This paper examines the influence of the portion of lead investors and investors' status on the investment performance of venture syndication. According to existing literature, multiple investors in VC syndicates can positively impact investment performance by investing both tangible and intangible resources in target companies based on market influence or high visibility. On the other hand, the presence of multiple leaders can cause conflicts in formulating and implementing investment strategy or free-riding problems or increase entry barriers for potential investors, lowering additional investment from existing investors. Therefore, we hypothesize that the relationship between proportion of lead investors and investment performance is inverted-U shape. Moreover, we predict that the status of VCs in the syndication will moderate the relationship between proportion of lead investors and investment performance since high-status actors are less likely to cooperate with or yield power to others. We tested these hypotheses using 24,677 VC syndicated investment data from 1991 to 2005 and found solid supports for the hypotheses. The findings suggest that firms need to consider relationship-based power dynamics among investors within a syndication and design effective role setting and coordination systems.

• Journal of Navigation and Port Research
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• 제47권6호
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• pp.430-436
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• 2023

Study on Changes in Vessel Traffic Services Due to Introduction of Maritime Autonomous Surface ShipsThe development of technologies related to Maritime Autonomous Surface Ships (MASS) has been actively progressing since the mid-2010s, focusing on themes such as collision avoidance, route planning, digital twin, and communication technologies. On the other hand, research on land-based infrastructure connected with MASS, such as logistics systems, port facilities, and vessel traffic services, has relatively received less attention. This study analyzed impact of emergence of MASS on existing vessel traffic service operations and proposed changes in control operations to prepare for its impact. To do this, current vessel traffic service operations were analyzed and elements of MASS technology that could affect vessel traffic control were identified. A survey was conducted among vessel traffic controllers to identify items related to the control of MASS. Results analyzed using the AHP method showed that preparation for emergency response and communication methods with MASS were the most important. Based on this, we were able to derive detailed plans for basic MASS control procedures and emergency response procedures based on data communication within maritime traffic control areas. MASS control procedures proposed in this study are expected to be used as a solution to resolve issues related to traffic safety of MASS in coastal areas.

• Journal of Advanced Navigation Technology
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• 제27권6호
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• pp.716-723
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• 2023

Global discussions are actively underway regarding the introduction of urban air mobility (UAM) to revolutionize the paradigm in the innovative mobility industry. While research related to airspace, vertiports, navigation, and communication pertinent to Korean UAM is actively pursued by relevant research institutions, there is a significant dearth in studies focusing on establishing concepts for operational management by UAM operators and formulating control procedures. The commercialization of UAM necessitates the establishment of standardized operational management concepts, pivotal as benchmarks for the individual system development among multiple UAM operators. This paper analyzes UAM exceptional law, operational readiness, existing regulations pertaining to commercial and rotary-wing aircraft, and proposes suitable approaches to formulate domestic low-density operational management and control procedures. By presenting strategies for conceptualizing operational management and control procedures in the initial low-density environment for UAM, this paper aspires to contribute to future trail operations and the wider adoption of UAM.

• Membrane Journal
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• 제34권2호
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• pp.154-162
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• 2024

Anion exchange membranes (AEMs) are essential components in water electrolysis systems, serving to physically separate the generated hydrogen and oxygen gases while enabling the selective transport of hydroxide ions between electrodes. Key characteristics sought in AEMs include high ion conductivity and robust chemical and mechanical stability in alkaline. In this study, quaternized Poly(terphenyl piperidinium)/cellulose nanocrystals (qPTP/CNC) mixed matrix membrane was fabricated. The polymer matrix, PTP, was synthesized via super-acid polymerization, known for its excellent ion conductivity and alkaline durability. The qPTP/CNC membrane showed a dense and uniform morphology without significant voids or large aggregates at the polymer-nanoparticle interface. The qPTP/CNC membrane containing 2 wt% CNC demonstrated a high ion exchange capacity of 1.90 mmol/g, coupled with low water uptake (9.09%) and swelling ratio (5.56%). Additionally, the qPTP/CNC membrane showed significantly lower resistance and superior alkaline stability (384 hours at 50℃ in 1 M KOH) compared to the commercial FAA-3-50 membrane. These results highlight the potential of hydrophilic additive CNC in enhancing ion conductivity and alkaline durability of ion exchange membranes.