본 연구는 지정학적 경쟁 시대에 원전 수출이 산업 거래를 넘어, 동맹 중심의 선택적 협력 구조 속에서 전개되는 가운데 한국이 수주 과정에서 미국과의 비대칭 동맹 관계로 인해 직면한 자율성의 제약을 분석하는 데 목적이 있다. 이를 위해 모로우의 자율성-안보 교환모델을 분석 틀로 도 입하고, 체코 원전 수주 사례를 검토하였다. 분석 결과 체코 원전 수주는 동맹 기반의 안보 논리가 중요하게 작용했으며, 한국은 수주를 위해 한· 미 원전기업 간 지식재산권 분쟁에서 미국의 조건을 수용하고, 기술적·정 책적 제약을 감내하였다. 이러한 결과는 원전 수출 문제가 동맹 결속과 지정학적 경쟁 관리의 수단으로 기능하기 시작했으며, 한국의 원전 외교 가 비대칭 동맹 속 자율성과 산업 안보가 교환되는 딜레마 구조에 놓여 있음을 보여준다. 향후 원전 수주를 위해 원전 기업의 경쟁력 제고와 더 불어 지정학적 경쟁과 동맹 기반 협력 체계를 전제로 한 국가 차원의 전 략을 모색할 필요성을 시사한다.

This paper is to study SOFC(Solid Oxide Fuel Cell) technology which is becoming increasingly more important in recent power development market. I will propose the most suitable fuel cell type through efficiency analysis by type of fuel cell in operation. In this paper, I analyzed the characteristics of SOFC development, theoretical study of the system technology and the level of progress in SOFC technology for each generation. In conclusion, through analysis of the operation data of the installed and operating fuel cell power generation system, it was found that SOFC is 45% more efficient than PAFC and 25% more efficient than MCFC.

This study focuses on electro-galvanizing of iron materials. Zinc plating provides superior corrosion resistance at a low cost due to zinc's lower potential (Zn: -0.76V) compared to iron (Fe: -0.44V), enabling it to act as a sacrificial layer. The paper also highlights the need for post-plating chromate or coating treatments to prevent the surface corrosion of zinc itself. The primary objective of this research is to analyze how different electro-galvanizing bath solutions influence key plating characteristics, such as uniformity of deposition and hydrogen embrittlement. The study examines various bath types, including acidic and alkaline solutions. Acidic baths, like zinc sulfate solutions, are shown to be suitable for high-current plating, ideal for high-speed processes like wire rod plating. Alkaline baths, such as cyanide solutions, produce a dense and glossy deposit, commonly used for decorative and anti-corrosion applications. Through a quantitative analysis of each solution's current efficiency and uniformity of deposition, this paper provides valuable insights for selecting the optimal plating bath in industrial applications.

목적: 본 연구에서는 단초점 안경을 착용한 근시안 소아를 대상으로 일정 기간 동안 교정굴절력 및 안축장의 변화를 추적 관찰하고, 연령 및 성별에 따른 변화 양상의 차이를 비교하였다. 방법 : 근시완화 렌즈 착용 등의 경험이 없는 단초점 안경을 착용한 근시안 소아(n=27안)를 대상으로, 굴절 검 사와 안축장 측정을 시행하고 6개월 후 추적 측정을 통해 교정굴절력 및 안축장 변화량을 분석하였다. 연구 대상은 7세에서 11세 사이의 소아 중 안과적 질환이 없고, 안경 이외의 근시 억제 처치를 받지 않은 자로 제한하였다. 교 정굴절력 및 안축장 변화는 초기값과 추적값 간의 차이로 산출하였으며, 연령 및 성별에 따른 차이를 비교하고 초 기 교정굴절력과 안축장 변화량 간의 상관관계를 분석하였다. 모든 자료는 SPSS 31.0 (SPSS Inc., Chicago, IL, USA)을 이용하여 통계 처리하였다. 결과 : 전체 대상자(n=27안)의 평균 안축장은 초기 24.03±1.12 mm에서 6개월 후 24.31 ±1.15 mm로 증가 하였으며, 평균 0.28±0.18 mm의 유의한 변화를 보였다. 연령군 비교에서는 7–8세군(n=14안)이 평균 0.37± 0.19 mm 증가한 반면, 9–11세군(n=13안)은 0.18±0.10 mm 증가하였고, 두 군 간의 차이는 통계적으로 유의하 였다(p=0.003). 성별에 따라 남아(n=14안)는 평균 0.32±0.21 mm, 여아(n=13안)는 0.24±0.14 mm 증가하였 으며, 두 군 간의 차이는 통계적으로 유의하지 않았다(p=0.218). 초기 교정굴절력과 안축장 증가량 간의 상관관계 는 통계적으로 유의하지 않았다(p=0.325). 안축장에 대해 교정굴절력, 각막곡률, 동공크기와의 상관관계 분석을 진행하였고, 모두 음의 상관관계를 보였다. 결론 : 단초점 안경을 착용한 소아를 대상으로 한 본 연구에서는 전체적으로 유의한 안축장 증가가 관찰되었으 며, 만 7세에서 11세 사이의 연령대 중 특히 7–8세군에서 더 빠른 성장 경향이 확인되었다. 성별과 초기 교정굴절 력과의 상관성은 유의하지 않았다. 안축장과의 상관관계 분석에서 교정굴절력, 각막곡률, 동공크기 모두 유의한 상 관관계가 나타났다. 12개월까지 추적관찰이 가능했던 7안을 대상으로 평균 교정굴절력은 –0.62 D, 안축장은 0.42 mm 증가하였다. 향후에는 더 많은 수의 대상을 통한 연령별 안축장 변화 분석이 필요하며, 본 연구 결과는 근시 진행 및 관리의 기초 자료로 활용될 수 있을 것으로 사료된다.

Machine learning (ML) techniques have been increasingly applied to the field of structural engineering for the prediction of complex dynamic responses of safety-critical infrastructures such as nuclear power plant (NPP) structures. However, the development of ML-based prediction models requires a large amount of training data, which is computationally expensive to generate using traditional finite element method (FEM) time history analysis, especially for aging NPP structures. To address this issue, this study investigates the effectiveness of synthetic data generated using Conditional Tabular GAN (CTGAN) in training ML models for seismic response prediction of an NPP auxiliary building. To overcome the high computational cost of data generation, synthetic tabular data was generated using CTGAN and its quality was evaluated in terms of distribution similarity (Shape) and feature relationship consistency (Pair Trends) with the original FEM data. Four training datasets with varying proportions of synthetic data were constructed and used to train neural network models. The predictive accuracy of the models was assessed using a separate test set composed only of original FEM data. The results showed that models trained with up to 50% synthetic data maintained high prediction accuracy, comparable to those trained with only original data. These findings indicate that CTGAN-generated data can effectively supplement training datasets and reduce the computational burden in ML model development for seismic response prediction of NPP structures.

The development of high specific surface area and mesoporous activated carbons is required to improve the electrochemical performance of EDLC. In this study, kenaf-derived activated carbons (PK-AC) were prepared for high-power-density EDLC via phosphoric acid stabilization and steam activation. The pyrolysis behavior of kenaf with respect to the phosphoric acid stabilization conditions were examined via TGA and DTG. The textural properties of PK-AC were studied with N2/ 77 K adsorption–desorption isotherms. In addition, the crystalline structure of PK-AC was observed via X-ray diffraction. The specific surface area and mesopore volume ratio of PK-AC were determined to be 1570–2400 m2/ g and 7.7–44.5%, respectively. In addition, PK-AC was observed to have a high specific surface area and mesopore volume ratio than commercial coconut-derived activated carbon (YP-50F). The specific capacitance of PK-AC was increased from 77.0–99.5 F/g (at 0.1 A/g) to 49.3–88.9 F/g (at 10.0 A/g) with activation time increased. In particular, K-P-15-H-9–10 observed an approximately 35% improvement in specific capacitance at a higher current density of 10.0 A/g compared to YP-50F. As a result, the phosphoric acid stabilization method was confirmed to be an efficient process for the preparation of high specific surface area and mesoporous biomass-derived activated carbons, and the kenaf-derived activated carbons prepared by this process have great potential for application as electrode active materials in high-power EDLC.

Proton Exchange Membrane Fuel Cells (PEMFCs) are emerging as reliable energy conversion devices for stationary power generation due to their high efficiency and environmental benefits. However, achieving long-term durability remains a critical challenge for commercialization. This study investigates the performance and degradation behavior of a PEMFC stack under 360 hours of constant current operation at approximately 0.22-0.23 A/cm², delivering a stack output of 1.5 kW. Electrochemical Impedance Spectroscopy (EIS) was employed to diagnose cell degradation, revealing increases in ohmic and charge transfer resistances over time. The results highlight the importance of uniform cell performance within the stack to prevent output limitations. Furthermore, we propose a framework for Remaining Useful Life (RUL) prediction to enhance system reliability. Future work will focus on applying these diagnostic techniques under varied operating conditions and integrating machine learning for advanced predictive models, aiming to support the development of stable, long-life PEMFC systems for stationary energy applications.

The most basic control algorithm of the electric power steering system in the Korean refrigerating cart CoCo was first commercialized as a prototype in 2022 after the Motor Driven Power Steering (Electric Power Steering) was verified and applied to automobiles. In order to overcome the heavy load of small machines such as refrigerating carts weighing 750Kgf, the driver's great power is required, which can cause muscle skeletal disorders, causing many female drivers to complain of pain, and recently applied electric steering technology because it was urgent. In this study, we study a control algorithm that complements the stability of the existing control algorithm applied to the electric power steering device for electric carts and analyze and verify the steering performance of refrigerated carts through analysis using MATLAB/SIMULINK.

The purpose of this study is to investigate the dynamic behavior of the internal cabinet of a nuclear power plant due to an earthquake and the characteristics of cabinet vibration reduction by TMD(tuned mass damper). For this purpose, the experimental device was constructed and numerical analysis was performed. The experimental device for the dynamic behavior of the cabinet consists of a cabinet, sliding base, mount, actuator, exciter, and measuring system, and the frequency response function of the cabinet was obtained. In addition, the time history of the cabinet was analyzed for acceleration and displacement through TMD design and cabinet 3D modeling. The natural frequency and response of the cabinet were lowered by approximately 26% due to the structural rigidity of the cabinet under the conditions of door opening and sliding base strong excitation. The acceleration and displacement characteristics of the cabinet varied depending on the TMD mass, and the cabinet vibration reduction effect was the best when the TMD mass was 60kg. The reduction in acceleration and displacement of the cabinet was approximately 12.1–16.2% and 10.1–19.1%, respectively.

The world's largest diesel power plant listed in the Guinness Book of World Records is Jordan's Amman Asian power plant, which produces a total of 573 MW of electric power. It consists of 38 units of 15MW capacity, and KEPCO achieved high profitability through the power plant. If a large capacity of 50MW clsss is applied, it will be newly listed in the Guinness Book of World Records even if only 12 units are constructed. Therefore, large-scale overseas orders for diesel power plants that require large capacity are expected in the future. The purpose of this study is to derive a installation offset by performing the shaft alignment analysis for large capacity 50MW shaft system. As a result, the offset of shaft system for the 50MW diesel power generation equipment was successfully derived through the bearing influence assessment and introduction of arrangement slope for main engine bearings.

In this study, static and dynamic analysis verification was performed to apply the fuel cell system to the E-PTO of the Wire aerial vehicle. First, structural analysis was performed to improve the weak points that occurred. Next, vibration analysis was performed on the fuel cell system for which structural safety review was completed according to the wide-band irregular vibration test standard. The analysis results showed that resonance occurred in a specific frequency band and local stress was high, so stiffness reinforcement was performed. After reinforcing the stiffness, stress was reduced through a decrease in transient response characteristics and resonance phenomenon.