To characterize the breakdown process, we newly introduce and define a dimensionless number called breakdown zone Reynolds number Reb. Reb represents the relationship between shear frictional resistance and inertial force, equivalent to (Vr /Vs)2. Vr and Vs are rupture and shear wave velocities, respectively. Reb also characterizes the energy budget relationship, seismic energy radiation, and its efficiency. Based on Reb, particle motion can be categorized into two cases: a) Reb≪1 and b) Reb ~1 or Reb>1. For case a), since the inertial force is negligible compared to the shear frictional resistance, the particle motion can be viewed as the response of a linear time-invariant system with the stress drop as an input function, and its impulse response function (IRF) is the second type of modified Bessel function with zeroth order supposing linear phase characteristics. The IRF is quite similar to the regularized Yoffe function. The particle velocity spectrum can be characterized with the approximated spectral attenuation slope in the high frequency range of ∝ω-0.6. The attenuation slope, however, would be changed to ∝ω-1.0 if we consider the pre-slip and phase delay of the response. Then, generic omega-square model can model a finite source’s source time function (STF). On the other hand, case b) shows that IRF has the same form as Brune’s omega-square model, and its STF has steeper spectral attenuation like omega-cube model. This means that the spectral characteristics of STF may change with the rupture velocity. Furthermore, we newly define the ratio of source-controlled fmax to corner frequency f c as Stokes number Sk, a function of Reb and approximately proportional to Reb 3/2. Remarkably, Sk delineates a Reynolds number similarity which is comparable to that of isotropic turbulence. The aggregated results of spectral inversion analysis for more than 130 shallow earthquakes occurring in Japan show that the analyzed fmax/ f c (=Sk) follow the theoretical relationship, and it is also demonstrated that the non-self-similarity parameter ε proposed by Kanamori and Rivera is related to the scale dependence of Reb. Finally, Reb is compared to the inertial number I, a representative dimensionless number governing the behavior of granular suspension as a model for the interaction between fault gouge and pore-pressure in fault core. As a result, Reb is equivalent to I 2 as we consider the differences in length scale and density in each definition. Consequently, I is uniquely linked to Sk by Reb, corresponding to the Stokes number for granular suspension. Hence, it can be asserted that Reb and Sk introduced in this study are representative dimensionless numbers which characterize the whole breakdown process and the behavior of pulverized fault core.

This study proposes an improved method for updating finite element models (FEM) by incorporating the random field characteristics of concrete material properties in reinforced concrete structures. Traditional FEM often assumes homogeneous material properties, which can lead to significant discrepancies between predicted and actual dynamic responses, especially in structures where the Young’s modulus (E) of concrete varies due to factors like curing conditions, material composition, and construction methods. We employed a Gaussian random field model and a system identification (SI) technique to address this limitation to optimize sensor placement. We developed an FEM updating method that incorporates the spatial variability of concrete elasticity. This optimization allowed for a more accurate capture of dynamic properties across various structural locations, resulting in FEM updates that reflect concrete’s inherent heterogeneity. The proposed method was validated through numerical examples, comparing dynamic response accuracy in models before and after updating. Results demonstrated that error values, measured in terms of maximum value error and normalized root mean squared Error (NRMSE), were significantly reduced in the updated models compared to the pre-update model. This approach effectively addresses the limitations of homogeneous assumptions in FEM.

본 연구는 디지털 플랫폼 기반 숏폼 콘텐츠 환경에서 대중음악이 청각적 기호(이어콘, 스피어콘 등) 로 기능하는 양상을 로제(Rosé)의 『APT』 사례를 중심으로 분석하였다. 특히 훅(Hook)의 반복성과 살 리언스(Salience) 효과에 주목하여 음악이 인지적 주목성과 기억 형성에 미치는 영향 및 플랫폼을 매 개로 문화적 경계를 넘나들며 확산되는 현상을 고찰하였다. 연구 방법으로 스테이크(Stake)의 본질적 사례 연구와 인(Yin)의 설명 사례 연구를 결합한 질적 접근을 채택하였으며, 문화기호학·인지심리 학·담론 분석을 복합적으로 활용하였다. 분석 결과, 『APT』의 훅 구조는 국내 청중에게 권주(勸酒) 놀이문화 코드로, 글로벌 청중에게 리듬 기반 놀이 코드로 각각 수용되었으며, 이로 인해 와이지 플러 스(YG PLUS) 주가 급등과 같은 실질적인 산업적 파급효과가 나타났다. 본 연구는 HCI(Human-Computer Interaction) 개념을 대중음악 콘텐츠 분석에 적용하고 청각 구조-인지 반응-문화 수용-플랫폼 확산으 로 이어지는 복합 작동 메커니즘을 통합적으로 제시함으로써, 대중음악 연구 분야에서 독창성을 보이 고 이론적 기여를 한다.

This study presents the implementation of a direct power control (DPC) system based on virtual flux for an eco-friendly ship utilizing a low voltage DC distribution within a Simulink environment. The proposed system regulates the DC bus voltage and the instantaneous power of the generator. The electrical load of the generator is classified into three levels (low, medium, and high) and subjected to ±10% variations. Under these conditions, the characteristics of the DC bus voltage and current, instantaneous active and reactive power as well as the voltage and current of the generator, are thoroughly analyzed. The simulation results indicate that the DC bus voltage and instantaneous active and reactive power remain stable and well-regulated at their set-points despite load fluctuations. Furthermore, the voltage and current of the generator, consistently maintain sinusoidal waveforms and remain in phase. These findings validate the effectiveness of the proposed virtual flux-based direct power control strategy, demonstrating its suitability for DC distribution applications in maritime vessels.

This study was attempted to solve the problem that the current training is not consistent with the actual working environment of the fishing vessel, even though the advanced fire extinguishing training for international fishing vessels is mandatory. As a result of the survey, the lack of timely use of fire extinguishing equipment and the difficulty of organizing the fire extinguishing organization were found, and the main problems were analyzed as low understanding of fixed fire extinguishing facilities, low awareness of fire-related laws and regulations, and inefficiency of fire extinguishing training. It was found that the current Seafarers Act does not clearly define the roles and responsibilities of advanced fire extinguishers, and lacks specific standards for designated educational institutions, so there is a problem that the accuracy and reliability of the training contents with the STCW-F Convention and STCW Convention are inconsistent. In addition, it has been confirmed that the fire extinguishing organization, internal communication, and fire extinguishing training in ships, as stipulated in international agreements, are not properly reflected in the domestic curriculum. In particular, the current training consists of general contents that do not take into account the characteristics of fishing vessels, so there is a lack of practical emergency response fire extinguishing training manuals. Therefore, this study proposes the development of customized training content for fishing vessels considering the special working environment and risk factors of fishing vessels based on international agreements, and emphasizes the need for policy support, such as strengthening participation of fishing vessels in education and training, and establishing a legal basis for the operation of emergency fire extinguishing organizations.

본 연구는 케이팝(K-POP) 산업의 대표 기업 중 하나인 JYP엔터테인먼트의 ESG(Environmental, Social, Governance) 경영 전략 실천 사례를 체계적으로 분석하였다. 문헌연구, 기업공시자료, 미디어 보도 분석을 통해 JYP의 환경 보호 활동, 아티스트 인권 보장 및 사회적 가치 실현, 투명한 지배구조 구축 사례를 정성적으로 고찰하였다. 분석 결과, JYP는 친환경 음반 제작 및 디지털 공 연 전환을 통해 환경 부문에서 간접적 기여를 하였으며, 체계적인 연습생·아티스트 보호 메커니 즘과 윤리경영 헌장을 통해 사회적 책임과 투명성을 강화하고 있었다. 경쟁사인 하이브, 에스엠 엔터테인먼트와의 비교 분석을 통해 JYP는 ‘사람 중심 경영’ 철학을 바탕으로 균형 잡힌 ESG 실천을 추구하고 있음을 확인하였다. 본 연구는 K-콘텐츠 기업의 지속가능성 확보를 위한 ESG 경 영의 중요성을 강조하며, 향후 문화산업 내 윤리성과 지속가능성 강화를 위한 실질적 전략 수립에 기여할 수 있을 것으로 기대한다.

Maintaining probiotic viability during storage, freeze-drying, and gastrointestinal transit is essential to ensure efficacy. The present study evaluated VitaShield Coating® (VSC), an innovative stabilization technology incorporating vitamins A, C, and E, for enhancing the viability of Bifidobacterium strains. VSC-coated B. bifidum BGN4 exhibited a significantly higher freeze-drying recovery rate (43.91±4.69%) compared to that of the uncoated group (15.31±6.53%, p<0.0001), with scanning electron microscopy (SEM) confirming preservation of structural integrity. Gastrointestinal stability also improved, as coated cells retained 26.21±2.41% viability in simulated gastric fluid, significantly outperforming uncoated cells (3.20±2.30%, p<0.0001). Gas chromatography-mass spectrometry (GC-MS) revealed a significant increase in polyunsaturated fatty acids (PUFAs) in coated cells, indicating enhanced membrane stability. Furthermore, storage stability of four Bifidobacterium strains (AD011, BORI, BGN4, and RAPO) was evaluated over 16 weeks at 25℃ and 30℃. The findings indicate that the VSC coating effectively protects probiotic strains under harsh storage conditions, mitigating viability loss over time. Overall, this study showed that the VSC coating serves as a multifunctional stabilization technology that provides mechanical, osmotic, and oxidative stress protection. Its ability to improve probiotic survival under harsh conditions enables its practical and scalable use in formulations and enhances stability.

This study aimed to enhance the operational efficiency and safety of offshore eel trap fisheries by developing six types of automated fishing equipment: a bait crusher, bait cutter, main line arranging device, trap cleaning device, eel sorting device, and fish pump system. Sea trials demonstrated that the bait crusher and bait cutter significantly reduced manual labor and processing time while maintaining bait quality. The main line arranging device improved productivity and safety by automating the sorting of looped cords. The trap cleaning device effectively removed fouling organisms using high-pressure water and rotating brushes. The eel sorting device enabled automatic size-based selection, improving resource management and operational efficiency. The fish pump system transferred eels rapidly with minimal physical damage, reducing unloading time by over 80% and decreasing labor requirements. A satisfaction survey of fishery participants confirmed that all developed devices were highly effective in reducing workload, enhancing safety, and improving operational performance. The automated equipment developed in this study is expected to contribute to the sustainable management of offshore eel trap fisheries and to offer potential applicability to other coastal and offshore fisheries.

본 연구의 목적은 국내 전력산업의 새로운 성장동력인 HVDC를 기술적 관점의 연구가 아닌 특허 기반의 서지계량학적 분석을 통해 기술의 발전 흐름과 핵심 기술군을 파악 하고자 하였다. HVDC 관련 국내외 특허데이터를 수집한 후 키워드 네트워크 분석과 IPC 코드 분석을 통해 기술 구조와 핵심 키워드를 도출하였으며, 'Voltage', 'System', 'Converter', 'Control' 등이 핵심 기술군으로 나타났다. 특히 IPC 트렌드 분석 결과 최근에는 보호 및 제어 중심의 지능형 시스템 기술이 부상하고 있음을 확인하였고, 이는 HVDC 기술이 전통적 송전 중심에서 통합 운영과 디지털 기반 시스템으로 진화하고 있음을 보여준다. 본 연구는 향후 HVDC 국내 기술개발 방향 설정과 글로벌 기술경쟁력 확보를 위한 전략 수립에 있어 기초자 료로 활용될 수 있을 것으로 기대된다.

이 논문은 조세희의 󰡔난장이가 쏘아올린 작은 공󰡕을 중심으로, 난장이 가족이 노동자로 변모하는 과정을 탐구하며, 이들을 둘러싼 자본가 세력과의 대립을 고찰한다. 난장이 가족은 역사적으로 핍박 받아온 하층 민 출신으로, 근대 사회에서도 여전히 가난과 불평등 속에서 살아간다. 본 연구는 작품 속에서의 노동자와 자본가 간의 갈등, 도덕적 가치의 상실, 그리고 사회적 연대의 중요성을 분석함으로써, 노동자 문제와 사회 구조의 모순을 심도 있게 조명한다. 특히, 난장이 가족의 큰아들 영수를 통해 노동자로서의 자각과 권리 찾기의 중요성을 강조하며, 신애와 지섭과 같은 중산층 인물들의 연대가 어떻게 하층민과 중산층 간의 연결고리를 형성하는지를 살펴본다. 이를 통해 작품이 제기하는 사회적 불화와 갈등이 노동자와 자본가 간의 대립, 도덕과 부도덕의 갈등, 안전과 위험의 대립으로 나타나고 있음을 분석한다. 본 논문은 이러한 연구를 통해 󰡔난장이가 쏘아올린 작은 공󰡕이 현대 사회에서도 여전히 유효한 문제들을 다루고 있음을 알려준다.