Dynamic responses of nuclear power plant structure subjected to earthquake loads should be carefully investigated for safety. Because nuclear power plant structure are usually constructed by material of reinforced concrete, the aging deterioration of R.C. have no small effect on structural behavior of nuclear power plant structure. Therefore, aging deterioration of R.C. nuclear power plant structure should be considered for exact prediction of seismic responses of the structure. In this study, a machine learning model for seismic response prediction of nuclear power plant structure was developed by considering aging deterioration. The OPR-1000 was selected as an example structure for numerical simulation. The OPR-1000 was originally designated as the Korean Standard Nuclear Power Plant (KSNP), and was re-designated as the OPR-1000 in 2005 for foreign sales. 500 artificial ground motions were generated based on site characteristics of Korea. Elastic modulus, damping ratio, poisson’s ratio and density were selected to consider material property variation due to aging deterioration. Six machine learning algorithms such as, Decision Tree (DT), Random Forest (RF), Support Vector Machine (SVM), K-Nearest Neighbor (KNN), Artificial Neural Networks (ANN), eXtreme Gradient Boosting (XGBoost), were used t o construct seispic response prediction model. 13 intensity measures and 4 material properties were used input parameters of the training database. Performance evaluation was performed using metrics like root mean square error, mean square error, mean absolute error, and coefficient of determination. The optimization of hyperparameters was achieved through k-fold cross-validation and grid search techniques. The analysis results show that neural networks present good prediction performance considering aging deterioration.

Climate change has led to a significant increase in jellyfish populations globally, causing various problems. For power plants that use nearby seawater for cooling, the intrusion of jellyfish into intake systems can block the flow, leading to reduced output or even shutdowns. This issue is compounded by other small marine organisms like shrimp and salps, making it urgent to develop solutions to prevent their intrusion. This study addressed the problem using the BioSonics DT-X 120 kHz scientific fish finder to conduct preliminary tank experiments. We also deployed underwater acoustic and camera buoys around the intake of nuclear power plant, utilizing a bidirectional communication system between sea and land to collect data. Data collection took place from July 31, 2023 to August 1, 2023. While harmful organisms such as jellyfish and salps were not detected, we successfully gathered acoustic data on small fish measuring backscattering strength (SV). Analysis showed that fish schools were more prominent in the evening than during the day. The highest fish distribution was observed at 3:30 AM on July 31 with an SV of -44.8 dB while the lowest was at 12:30 PM on the same day with an SV of –63.4 dB. Additionally, a solar-powered system was used to enable real-time data acquisition from sea buoys with smooth communication between the land server and the offshore buoy located 1.8 km away. This research developed an acoustic-based monitoring system for detecting harmful organisms around the intake and provided foundational data for preventing marine organism intrusion and planning effective measures.

19세기 근대로 가는 길목에서 조선은 외세의 침입이라는 새로운 시대 상황을 맞게 되었다. 이러한 외압(外壓)에 대응하는 데 가장 근본이 되었 던 것이 당시는 수군(水軍)이라 불렸던 조선 해군(海軍)의 군사력이었고 할 수 있다. 이러한 인식을 바탕으로 본 연구는 19세기 조선 해군 전력 의 일단(一端)을 살펴볼 수 있는 실증적 사례 연구를 진행하였다. 구체적 으로 전라좌수영(全羅左水營)에 속해 있던 광양현(光陽縣)과 경상우수영 (慶尙右水營)에 속해 있던 하동부(河東府)의 수군 전력의 실태를 파악하 고자 하였다. 이들 두 군현은 19세기 ‘중기(重記)’ 자료가 남아 있다. 중 기 자료는 작성 당시 지방 군현의 군비 실태를 파악할 수 있는 가장 좋 은 자료이다. 따라서 이 중기 자료를 중심으로 19세기 조선 해군 전력의 일단을 살펴보았다. 이와 더불어 각종 관찬 자료와 읍지(邑誌), 사례(事 例) 등을 비교 검토하였다. 이 연구를 통해 19세기 조선 해군 전력의 일 단을 확인하였다. 당시 조선 정부는 해양 방위[海防]에 상당한 관심을 가 지고 있었지만 이에 대응한 해군 전력의 향상은 적절히 이루어지지 못한 것으로 보인다. 이는 본 연구를 통해 일부 확인되는 것처럼 특히 지방 군현의 수군 전력은 형식적 전력을 유지하는 데 그쳤고, 그 실제는 전력 이 약화되고 있었던 것으로 여겨진다.

For the OPR1000, a standard power plant in Korea, an analytical model of the containment building considering voids and deterioration was built with multilayer shell elements. Voids were placed in the vulnerable parts of the analysis model, and the deterioration effects of concrete and rebar were reflected in the material model. To check the impact of voids and deterioration on the seismic performance of the containment building, iterative push-over analysis was performed on four cases of the analytical model with and without voids and deterioration. It was found that the effect of voids with a volume ratio of 0.6% on the seismic performance of the containment building was insignificant. The effect of strength reduction and cross-sectional area loss of reinforcement due to deterioration and the impact of strength increase of concrete due to long-term hardening offset each other, resulting in a slight increase in the lateral resistance of the containment building. To determine the limit state that adequately represents the seismic performance of the containment building considering voids and deterioration, the Ogaki shear strength equation, ASCE 43-05 low shear wall allowable lateral displacement ratio, and JEAC 4601 shear strain limit were compared and examined with the analytically derived failure point (ultimate point) in this study.

This study was conducted to determine the efficiency of the distribution process of the abalone industry, that is, whether there is market dominance. In addition, it was intended to find out whether there is an asymmetric price transfer phenomenon between the distribution stage of the abalone industry. The results of this study are summarized as follows. First, the asymmetric price transition effect on the abalone price between producer and wholesale market was found to be positive. It means that the distribution structure is incomplete between the producer and the wholesale market and the abalone market is operating inefficiently. Second, as a result of estimating the market power between the producer and the wholesale market, the market power coefficient between the producer and the Hanam wholesale market, and the producer and the Incheon wholesale market were 0.0618 and 0.0735. Summarizing the analysis results, the abalone market has an asymmetric price transition between producer and wholesale markets, but the market dominance coefficient is relatively low. These results suggest that the asymmetry of price transition is mainly caused by market dominance, but can also be caused by other factors such as information asymmetry. In the future, in addition to the market dominance of the abalone market, it is judged that research on factors related to the asymmetry of price transition is necessary.

본 논문은 이탈리아 미래주의 화가 루이지 루솔로가 1913년 3월에 선포한 「소음의 예술」 이 기계의 소리를 찬미하며 새로운 미학을 주창하면서도 한편으로는 미래주의자들이 가졌던 기술 권력에 대한 욕망을 내재하고 있음을 고찰하고자 한다. 미래주의자들은 산업화와 도시 화로의 역동적인 발전과 변화를 옹호했고 현대의 기술 발전을 적극적으로 수용하였다. 루솔 로는 현대 도시의 환경을 반영하는 소음을 음악에 편입시키고 인토나루모리와 같은 소음 악 기를 제작하면서 소음의 미학적인 잠재력을 모색하였다. 본 논문은 루솔로가 소음을 수용하 여 새로운 감각 경험을 제공하는 실험을 전개함으로써 현대 음악의 가능성을 확장한 기여를 인정하지만, 이와 동시에 전쟁의 소음도 긍정했던 점에 주목한다. 이러한 루솔로의 입장을 기계에 대한 미래주의의 태도 및 파시즘의 국가주의와 연관지어 분석하고자 한다. 이를 위하 여 다수의 미래주의 선언문들에서 표명된 기계에 대한 전망을 돌아보고, 기술과 전쟁을 현대 화의 근간으로 삼았던 미래주의의 급진주의적인 전망이 파시즘의 권력에 대한 욕망을 반영 하고 있음을 살펴보고자 한다. 궁극적으로는 「소음의 예술」이 전망했던 미학적인 혁신이 미 래주의가 추구했던 권력 욕망에서 결백하지 않음을 드러내고자 한다.

In recent years, the global geopolitical landscape has been significantly influenced by nations asserting dominance in key sectors, including finance, intellectual property, and military industries. This ascendancy allows states to dictate terms and wield substantial impact on the world order. In particular, China has emerged as a pivotal player, strategically utilizing innovation and economic prowess to reshape international relations. This research examines China’s role in redefining global power dynamics, particularly within Africa, while evaluating the effectiveness and criticisms of its “soft power” strategies. China’s robust presence in critical sectors such as finance, intellectual property, and military industries underscores the correlation between leadership in these domains and global influence. The country’s economic and technological prowess has positioned it as a formidable player, enabling it to exert significant control over international rules and norms. The ramifications of such dominance transcend mere economic power, influencing diplomatic relations and shaping the international order.

This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.