This study investigates the structural mechanisms underlying user acceptance of generative AI services by integrating cognitive and affective dimensions of user experience. Based on the Technology Acceptance Model, Expectation–Confirmation Theory, and flow theory, a research model was developed and tested through an online survey of 387 Korean users with more than three months of experience. Structural equation modeling confirmed that cognitive and affective responses significantly influence satisfaction and trust, which in turn predict loyalty, with trust showing the strongest direct effect. Satisfaction and trust also mediated these relationships, while flow strengthened the satisfaction–loyalty path and resistance to technology was not significant. These findings highlight the importance of incorporating emotional and experiential factors alongside functional aspects. Practical implications suggest that fostering trust, engagement, and perceived value is essential for sustaining loyalty in generative AI services.

This study analyzed the structural performance of a microalgae-based lightweight ecological integration system for large-span structures to achieve carbon neutrality. To address the load problems of existing soil-based ecological systems, a lightweight system utilizing microalgae bioreactors was proposed, and structural performance was evaluated for four types of large-span structures: truss, arch, dome, and cable structures. Structural analysis results through finite element analysis showed that the proposed system achieved a 70% load reduction effect compared to existing systems, with structural performance improvements including 35-40% reduction in maximum deflection, 30-35% reduction in maximum stress, and 25-30% increase in natural frequency. Environmental performance analysis confirmed CO₂absorption capacity of 12-18 kg per m² annually and PM2.5 reduction effects of 15-25%. Economic analysis results indicated that benefits of 3.95-6.7 million KRW per year are generated for a 1,000 m²reference area, creating cumulative benefits of 179.75-227.5 million KRW over 25 years. Verification through the German BIQ House case confirmed CO₂reduction performance of 6 tons per year for 200 m², demonstrating the practical applicability of the system. This study presented the potential of an innovative ecological integration system that can ensure structural safety of large-span structures while simultaneously contributing to carbon neutrality.

This study experimentally and numerically evaluated the fire risks and structural vulnerabilities of tunnel-type noise barriers (hereinafter referred to as hereinafter referred to as soundproof tunnels). In Korea, soundproof tunnels are typically constructed using combustible polymeric materials such as polymethyl methacrylate (PMMA) and polycarbonate (PC) for noise reduction and lightweight design. However, due to their enclosed structural characteristics, concerns have been raised regarding heat and smoke accumulation as well as the rapid spread of fire. In this study, fire scenarios were established by varying structural conditions, including roof opening ratios and the presence or absence of central partitions, and analyzed using the Fire Dynamics Simulator (FDS). The results demonstrated that PMMA exhibited a lower thermal decomposition temperature and a higher heat release rate, indicating a higher level of fire risk, while PC showed superior fire resistance with higher decomposition temperature and delayed ignition properties. PMMA rapidly exceeded the critical thresholds for temperature and radiative heat flux, resulting in complete combustion. Central partitions were found to accelerate smoke spread, whereas side or roof openings facilitated smoke discharge to the exterior, contributing to fire suppression and improving life safety. In conclusion, this study confirmed that the fire risks of soundproof tunnel are jointly influenced by the combustion characteristics of the materials and the structural conditions. The findings are expected to serve as fundamental data for material selection and design standard improvements in future soundproof tunnel fire safety.

본 연구는 노인환자를 돌보는 요양병원이라는 특수한 환경에서 정서 적, 윤리적 요인이 간호업무수행에 미치는 영향을 분석하고자 요양병원 간호사의 공감역량과 윤리적민감성, 환자중심간호, 간호업무수행 간의 구 조적 관계를 파악하고, 간호업무수행 향상을 위한 이론적, 실무적 기초자 료를 제공하기 위해 수행되었다. 연구대상은 국내 요양병원간호사 230명 을 편의표집 하였으며, 연구결과로 모형 적합도는 χ²/df=165.517, CFI=.945, TLI=.928, RMSEA=.092로 양호하였으며, 공감역량은 윤리적민 감성(β=.478, p<.001)과 환자중심간호(β=.716, p <.001)에 유의미한 영향을 미쳤으며, 간호업무수행(β=.431, p <.001)에는 간접적으로 영향을 미치는 것으로 나타났다. 윤리적민감성은 간호업무수행(β=.188, p <.001)에, 환자 중심간호는 간호업무수행에 매개요인으로 작용하였다(β=.477, p <.001). 간호업무수행 향상과 환자중심간호를 실천하기 위한 간호인력 배치 기준 을 재정비하고, 다학제 팀의료 상호 협업 중심의 전인적인 돌봄 지원 체 계를 구축하는 것을 제시한다.

선박용 프로펠러는 선박 추진 성능과 연비에 직접적인 영향을 미치는 핵심 부품으로, 제작 과정에서 높은 정밀도가 요구된다. 사형주조는 복잡한 형상의 금속 부품 제작에 널리 사용되는 공정이지만, 주조 과정에서 발생하는 열적 팽창과 냉각 수축은 최종 치수 오 차와 가공 비용 증가를 초래하는 주요 원인이다. 본 연구에서는 사형주조 과정에서 발생하는 열팽창 및 수축 현상을 정밀하게 예측하고, 이를 고려한 최적의 치수 여유 설정을 통해 연마 작업을 최소화하는 설계 방안을 제안하였다. 알루미늄 청동 합금(ALBC3)을 사용한 프로 펠러를 대상으로 열팽창 공식과 유한요소해석(FEM)을 적용하여 블레이드, 허브, 전체 지름 등 각 부위별 변형을 정량적으로 분석하였다. 분석 결과, 블레이드 너비와 두께는 약 1.9%, 허브 직경은 1.5%, 전체 지름은 2.0%의 여유를 두는 것이 적절한 것으로 나타났다. 이러한 최 적 치수 여유를 적용한 결과, 최대 23kg의 재료 절감, 30만 원 이상의 제작 비용 절감, 작업 시간 50~60% 단축 등의 정량적 개선 효과가 확인되었다. 최적 설계를 적용함으로써 추가 연마 작업과 재료 손실을 줄일 수 있으며, 이에 따른 비용 절감 효과도 기대된다. 본 연구 결 과는 선박용 프로펠러 제작 과정의 품질 향상과 생산성 제고에 기여할 수 있을 것으로 판단된다.

This study numerically investigated thermal-structural characteristics of a liquefied hydrogen (LH) storage cylinder with varying inner pressures and surrounding temperatures. A thermal-structure coupled analysis approach was used to predict the thermal-structural characteristics of the LH storage cylinder. For the simulation, the shape of the LH storage cylinder was simplified using SUS 316L and Carbon Fiber Reinforced Plastic (CFRP) materials. As a result, the inner pressure was a crucial factor determining the structural property (i.e., stress and deformation) of the LH storage cylinder. The high pressure led to increased stress and deformation. Additionally, the surrounding temperature affected the stress and deformation of the LH storage cylinder. For example, at a high surrounding temperature, the temperature gradient along the cylinder increased, thereby causing the occurrence of thermal stress. However, this temperature effect on the stress was negligible compared to the effect of inner pressure. The findings of this study will provide meaningful data for improving the structural safety of LH storage systems.

In this study, the design of shock tower mounting, a type of shock absorber mounting for four-wheel drive vehicles, was addressed through structural analysis. In the case of existing shock tower mounting components, cracks occurred in the shock tower frame side weld joints, so the maximum stress should be reduced to extend the life of the designed components. Based on this, various design changes were performed on the shock tower mounting components, and the maximum stress generated through structural analysis of each design change model was compared. For the structural analysis, a load of 40,000 N was applied in the axial direction of the shock absorber, and the results were relatively analyzed and compared. As a result of the analysis of the shock tower mounting components through the design change, Case 3, a model that alleviated the stress concentration applied to the body mounting, increased the strength compared to the existing model, and the stress in the shock tower frame side weld joints was reduced by 16.3%.

The chip processing system of large scale machine tool, such as planomiller, turning machine, boring machine and CNC machine, has been continuously used in many industrial fields. As the performance of chip processing system is improved, cutting work with high-precision is also required. This study aims to study the characteristics of the edged part of cutter depending on removing the cutter support in cutter assembly. As the results, the damaged spot in edged part of cutter was different whether the cutter support was installed or not. By removing the cutter support, the safety factor of edged part of cutter was decreased about 4.7 times and furthermore there were some advantages in less than 1.7kN of cutting force.

일체식 교대 교량 공법은 1930년대부터 미국과 캐나다에서 적용되었으나, 국내에서는 공용 기간이 짧아 설계, 시공 및 유지관리 경 험이 부족하다. 또한, 장기 거동에 대한 추적 데이터가 부족해 설계 시 예측한 구조 거동의 안정성 검증이 필요하다. 본 연구는 국내 공 용 중인 일체식 교대 교량을 대상으로 장기 계측을 수행하고, 선행 연구에서 제안된 수치 해석 모델을 적용해 구조 안정성과 모델의 적용성을 검증하였다. 계절적 온도 변화에 따른 변위 값의 크기와 변화 형상을 정성적으로 평가하고, 실측과 수치 해석 변위 값을 t 검 정으로 비교해 정량적 검증을 수행하였다. 분석 결과, 대상 교량들은 예측 값과 실측 값이 큰 오차 없이 안정적인 구조 거동을 보였다. 일부 교량에서는 교대 밀림으로 인한 신축 이음 축소와 교대 벽체 및 거더부 협착이 관찰되었다. 모델링 정확도를 높이기 위해 지반- 교대 스프링 강성과 교좌 전단 강성을 설계 값보다 높게 반영하는 것이 필요하다.

During the reign of King Sejong in the Joseon Dynasty (1433-1438), the Daegyupyo (large gnomon) was produced. The Daegyupyo, with a crossbar (horizontal bar), was used to observe the length of the gnomon’s shadow cast by the sun passing at the meridian. The shadow of this crossbar can be obtained using a measurable device called the Yeongbu (shadow definer). These Daegyupyo and Yeongbu are described in detail in the “Treatise on Astronomy” of Yuan History or “Celestial Spheres and Globes” of Jega-Yeoksang-Jjp (Collected Discourses on the Astronomy and Calendrical Science of the Chinese Masters). According to Jega-Yeoksang-Jjp, the Yeongbu had a structure similar to a door attached to its frame. A pinhole is located in the center of a copper leaf corresponding to the door of the Yeongbu. The image of the sun’s meridian transit and the shadow of the crossbar through the pinhole are projected onto the surface of the Daegyupyo’s ruler stone. Unlike the width and length of the Yeongbu, the height of the Yeongbu is not recorded. This research analyzed the height of the Yeongbu required to maintain the constant distance from the pinhole to the ruler stone surface. Based on these assumptions, it was estimated that 8 to 13 Yeongbu of different heights would be needed for observations using the Daegyupyo in Seoul. To accommodate the need for Yeongbu of various heights, this study proposed a model for a stackable Yeongbu with an adjustable height.

Truss structures, widely used in engineering, consist of straight members transferring axial forces. Traditional analysis methods like FEM and the Force Method become computationally expensive for large-scale and nonlinear problems. Surrogate models using Artificial Neural Networks (ANNs), particularly Physics-Informed Neural Networks (PINNs), offer alternatives but require extensive training data and computational resources. Variational Quantum Algorithms (VQAs) address these challenges by leveraging quantum circuits for optimization with fewer parameters. Variational Quantum Circuits (VQCs) based on Quantum Neural Networks (QNNs) utilize quantum entanglement and superposition to approximate high-dimensional data efficiently, making them suitable for computationally intensive tasks like surrogate modeling in structural analysis. This study applies QNNs to truss analysis using 6-bar and 10-bar planar trusses, assessing their feasibility. Results indicate that residual-based loss functions enable QNNs to make reliable predictions, with increased layers improving accuracy and a higher Q-bit count contributing to performance, albeit marginally.

이 연구는 다목적 선박(MPV)의 공기역학적 구조물 설계, 분석 및 향상을 통해 그린 워터 압력에 의한 구조적 안전을 보장하고, 탈탄소화 및 에너지 효율성에 이바지하는 방법을 기술하였다. 유한 요소 분석(FEA)을 통한 초기 평가에서 좌굴 발생에 대한 잠재적인 취약점 이 있음을 확인하였다. 이러한 문제를 해결하기 위해 보강재(Carling stiffener)와 두께 증가를 통하여 응력을 재분배하고 국부적인 좌굴 발생의 위험을 최소화하였다. 보강 후 분석 결과, 한국선급(KR)의 안전 기준인 항복 강도, 미국 선급(ABS) 좌굴 강도 및 노르웨이 표준(NORSOK) 변 위 기준을 모두 충족하는 것이 확인되었다. 결과적으로 고유치 좌굴 해석 결과가 안전 기준을 초과하고 최대 변위가 허용 한계 내에 있는 등 중요한 개선이 이루어졌다. 이러한 개선은 극한의 해양 조건에서 운영 신뢰성을 보장할 수 있다. 이 연구는 공기역학적 항력 감소와 구조적 안전성의 이중적인 이점을 강조하며, 국제 해사 기구(IMO)의 2050 탈탄소화 목표에 부합하는 연료 효율성 및 온실가스 배출 감소에 이바지할 수 있다. 연구 결과는 다양한 선박 유형에 걸쳐 항력 감소 기술을 확장하기 위한 기초 자료를 제공하며, 지속 가능하고 탄력적인 해양 운영을 위한 대안을 제시하였다. 향후 연구는 구조적 안전 평가를 가속할 수 있는 단순화된 모델링 기술 개발에 집중할 것이다.

The rotary type dust remover is a device in which the rake assembly filters and processes clumps in the water while rotating and repeating movements along the track. It is installed in the pump suction part of the drainage pump station and the rainwater pump station to protect the pump to ensure smooth drainage. Since the rake assembly plays a key role in filtering out complications while passing through the water, stainless steel is applied to all components constituting it, and damage or failure due to deformation causes a crisis in case of heavy rain. This is because the existing rake assembly is excellent in rigidity, but all components are assembled by welding, which takes a lot of time for repair and replacement. In this study, shape design for rakes and assemblies of the rotary type dust remover, structural analysis to secure reliability, and demonstration tests were conducted through prototype production. Through this, it is intended to help prevent the stiffness of the joint of the rotary type dust remover from deteriorating, reduce time and cost, and efficient operation.

In this paper, the design feasibility of the high-temperature rotation test jig for the operating state of gas turbine blades was confirmed through thermal structural analysis and modal analysis. The structural analysis model was composed of assembled blade, disc, cover, and shaft. Here, the disc was designed to be assembled with two types of blade. First, thermal analysis was performed by applying the blade surface temperature of 800°C. Next, structural analysis was performed at 3600 RPM, the normal operating condition, and 4320 RPM, the overspeed operation condition. Lastly, modal analysis was performed to examine the natural frequency and deformation of the jig. The FE analysis showed that the temperature decreased from the blade to disc dovetail. Additionally, both the blade and disc showed structural stability as the maximum stress was below the yield strength. Also, the first natural frequency was 636.35Hz and 639.43Hz at 3600RPM and 4320RPM, respectively, satisfying gas turbine design standards and guidelines. Ultimately, the designed test jig was confirmed to be capable of high temperature and rotation testing of various blades.

The green supply chain has become a central concern for global businesses, particularly in maritime industries, where sustainable development is pursued as both an economic growth strategy and a means of environmental preservation. This study seeks to identify the key challenges to implementing green supply chain in Vietnam. The Analytical Hierarchy Process (AHP) is employed to assess the significance of various factors, while Fuzzy Structural Modeling (FSM) is used to explore their interrelationships. Five major factors - economic, technological, organizational, governmental, and social - are identified as critical to the implementation of green supply chain. The study highlights that the organizational factor is the most crucial, with customer pressure, particularly regarding environmental standards from export countries, being the most influential sub-factor. The findings provide important insights for developing government policies, offering support to businesses, and guiding investment decisions in green supply chain.

This study investigates the structural stability of a telescopic arm designed for a painting robot through finite element analysis (FEA). As factory automation progresses, robots are increasingly used to replace hazardous tasks like painting. However, the heavy weight of telescopic arms poses significant control challenges. This research specifically examines the structural stability of a 7.4-meter telescopic arm, designed for use in a 14m x 14m large-scale block painting environment. The telescopic arm consists of six steel links, each ranging from 700 mm to 1500 mm, and supports a 50 kg painting robot mounted at the end of Link 6. Using Dassault System’s Abaqus2022 software, simulations were performed in both stretched and rotated modes to analyze self-weight effects and structural stability. The results revealed maximum deflection of 92.3 mm in stretched mode and 127.3 mm in rotated mode, with the highest stress concentration of 416.8 MPa occurring at the Link 3 and Link 4 connection. To improve stability, additional reinforcement materials and an increase in connector thickness from 40 mm to 80 mm were applied, successfully reducing maximum stress to 94.3 MPa. These findings suggest an effective enhancement in the stability of the telescopic arm under various operational modes.