In the fabrication of curved steel plates for shipbuilding, post line-heating is widely used to induce plastic deformation by applying local heat and controlling residual stress. However, the process is still dependent on skilled labor and empirical methods, making it difficult to ensure consistent quality and precision. To improve the automation and standardization of the post line-heating process, this study aims to investigate the relationship between heating conditions and the resulting deformation behavior of marine structural steel plates. Experiments were conducted on AH36 steel specimens under 24 different heating conditions, including three plate thicknesses (12mm, 16mm, 20mm), two heating speeds, two gas flow ratios, and two torch tip types. Maximum deformation was measured across 15 locations per case. The results showed that thinner plates exhibited greater deformation, and higher heat input—such as slower heating speed and higher gas flow—led to increased deformation. The 800-type torch tip, with a narrower flame focus, also induced larger deformation than the 1000-type. These findings provide fundamental data for optimizing post line-heating parameters and establishing automated correction processes in shipbuilding applications.

This study investigated the hot deformation behavior and microstructural evolution of PH13-8Mo precipitation-hardening stainless steel. Hot compression tests were performed at temperatures ranging from 900 to 1,200 °C and strain rates of 0.01 to 10 s-1. Constitutive equations based on the Zener-Hollomon parameter were established by considering the compensation of strain, where the material constants were fitted with 6th-order polynomials. The established model showed high predictability with a correlation coefficient of 0.994 and an average absolute relative error of 4.39 %. A hot processing map was developed based on the Dynamic Materials Model, identifying unstable regions characterized by negative instability criteria under low-temperature/high-strain-rate conditions, as well as specific moderate-rate zones. Electron backscatter diffraction (EBSD) integrated analysis [inverse pole figure (IPF), kernel average misorientation (KAM), and grain orientation spread (GOS)] revealed that while dynamic recrystallization promoted grain refinement through necklace structures at 900 °C and 0.01 s-1, high-temperature deformation at 1,200 °C led to significant grain coarsening and high transformation-induced stress. Furthermore, regions of instability were confirmed to cause flow localization and strain hotspots, detrimental to structural integrity. Consequently, the moderate temperature region around 1,100 °C with a low strain rate is proposed as the optimal window for achieving uniform and stable prior austenite grain structures.

This research presents a GRNN(General regression neural network) approach for modeling the high temperature deformation flow behavior of 316L stainless steel under 800℃, 900℃ and 1000℃ and strain rates of 0.0002/s, 0.002/s and 0.02/s. There are many machine learning approaches of modeling the hot deformation of metallic alloys. Among them, the neural network approach is one of the most popular. However, the neural network approach takes a relatively long time and effort to compose and optimize the final model. In this research, GRNN is applied to study its applicability for modeling the hot deformation flow stress behavior. The prediction results were studied by calculating various types of error and observing the distribution of prediction error. The predicted results by the GRNN were very accurate and the GRNN was found to be highly applicable to modeling the flow stress of the hot deformation of 316L stainless steel.

This study investigates the deformation behavior of AH32 steel plates under various line heating conditions in the post line-heating process. A total of 24 experimental cases were conducted by varying material thickness (12mm, 16mm, 20mm), heating speed, oxygen and acetylene flow rates, and torch tip size. Deformation was measured at 35 points per specimen, with emphasis on the maximum deformation at the 300mm X-axis location. The deformation results were classified into three groups: high (≥4.0mm), medium (2.0–3.9mm), and low (≤1.0mm). The results confirmed that material thickness had the greatest effect on deformation, followed by heat input parameters such as heating speed and gas flow rate. High deformation occurred under low heating speed and high flow rate conditions, while low deformation was observed in thick plates with fast heating and low flow rates. These findings highlight the importance of controlling heat input and geometric factors for deformation correction. The data acquired from this study can be utilized as a reference for optimizing automated post line-heating processes in shipbuilding.

This study investigated the hot deformation behavior and dynamic recrystallization (DRX) characteristics of a coarse-grained Fe-24Mn steel slab using plane strain compression (PSC) tests. Tests were conducted at 900-1,000 °C and strain rates of 0.5-10 s-1. Constitutive equations based on the Zener-Hollomon parameter accurately predicted flow stress ( ). A processing map based on the Dynamic Materials Model (DMM) predicted flow instability at high strain rates (10 s-1) due to a negative strain rate sensitivity exponent. However, electron backscatter diffraction (EBSD) analysis revealed that these regions actually exhibited a fully recrystallized microstructure with low Kernel Average Misorientation (KAM) values, contradicting the DMM prediction. This discrepancy is attributed to adiabatic heating during high-speed deformation, which induces thermal softening and provides the driving force for DRX. Consequently, the region with negative power dissipation efficiency at high strain rates should be reinterpreted not as a failure zone, but as a window for efficient microstructural refinement. The study identifies 950 °C and 10 s-1 as the optimal processing conditions for grain refinement of the as-cast slab.

This study investigates the thermo-mechanical behavior and residual stress characteristics of friction stir welding (FSW) in an aluminum inverter housing using finite element analysis (FEA). FSW experiments were first conducted under various tool rotation and traverse speed conditions, and temperature histories were measured using K-type thermocouples. The optimal process condition was identified through tensile testing, and the heat input was estimated by comparing experimental and numerical results. The estimated heat source was incorporated into a transient thermal elasto-plastic analysis to evaluate deformation and residual stresses in an inverter housing model. The results indicated that residual stress distributions varied depending on the welding start position. In particular, when welding started at P3 (near thick ribs and bosses) residual stresses were reduced by approximately 30% compared to P1, owing to the higher local stiffness and enhanced heat dissipation that mitigated temperature gradients. Conversely, welding initiated at P1, a flat region with insufficient reinforcement, resulted in higher stress concentrations. These findings confirm that the welding start position significantly influences residual stress behavior in inverter housings and provide fundamental insights for developing residual stress control strategies in FSW of large-scale components.

샤옌은 루쉰의 소설 축복(1924)을 영화 <축복>(1956)으로 각색하는 과정에서 원 작과 상이한 서사적 양상을 드러낸다. 본고는 이러한 변용을 단순한 충실성의 문제 로 환원하기보다, ‘17년 시기’ 중국영화의 정치⋅이념적 조건 속에서 각색 텍스트의 의미가 어떻게 재구성되고 배치되는지를 검토한다. 이를 위해 린다 허천(Linda Hutc heon)의 각색 이론을 방법론적 틀로 삼아, 각색을 고정된 결과물이 아니라 맥락 속 에서 이루어지는 과정으로 파악하고자 한다. 특히 지식인 서사의 변형, 보이스오버 (画外音, Voice-over)의 삽입, 그리고 ‘문턱 찍기’ 장면의 서사적 재구성에 주목하여, 화자 구조와 시점, 장면 연출의 변화가 관객의 해석 가능성과 서사적 의미 조직 방 식에 어떠한 영향을 미치는지를 분석한다. 이러한 논의는 루쉰 각색 연구에서 상대적으로 덜 조명되어 온 각색의 맥락성과 재맥락화의 문제를 구체적 사례를 통해 재 검토하게 한다는 점에서 의의를 지닌다.

본 논문은 예이츠(W. B. Yeats)의 후기 시에 나타나는 몸의 위상을 니 체(Friedrich Nietzsche)의 몸 철학, 특히 􋺷차라투스트라는 이렇게 말했다􋺸에 제시된 ‘큰 이성’과 ‘작은 이성’ 개념을 중심으로 분석한다. 엘리엇(T. S. Eliot)이 지적했듯, 예이츠는 노년에 이르러서도 자기 갱신을 지속하며, 노쇠한 몸을 단순한 한계가 아니 라 새로운 사유와 창조를 가능하게 하는 동력으로 재구성한다. 후기 시에서 몸은 생물 학적 쇠퇴의 상징이 아니라 상상력과 예술적 통찰의 근원으로 기능하며, 이는 전통적 인 형이상학적 이원론을 비판하고 몸을 사유와 가치 창조의 중심으로 본 니체의 철학 과 긴밀히 공명한다. 본 논문은 자아와 영혼의 대화 , 탑 , 미친 제인이 주교와 이 야기하다 를 중심으로, 자아가 영혼을 포용하며 ‘나’에서 ‘우리’로 확장되는 과정, 노 쇠한 몸이 상상력과 창조적 활동을 촉발하는 양상, 몸과 정신이 대립을 넘어 상호 의 존적 관계로 재구성되는 방식을 분석한다. 이를 통해 본 논문은 예이츠가 니체의 사유 를 수용하면서도 몸과 정신의 관계를 위계적 포섭이 아닌 상호적 조화의 구조로 변용 하고 있음을 밝힌다. 아울러 노쇠한 몸을 창조적 사유를 갱신하는 근원적 힘으로 재배 치함으로써 예이츠 후기 시의 이해를 위한 새로운 해석적 틀을 제시한다.

Rapid post-earthquake retrofit decisions require reliable estimates of interstory drift ratio. Conventional field practices either depend on instrumented measurements constrained by sparse sensor coverage or rely on qualitative expert judgment. This study aims to develop a CNN-based interstory drift ratio prediction method for reinforced concrete columns using strain-derived damage images. Reinforced concrete columns are modeled and analyzed in OpenSees to obtain strains and displacements. Strain fields are converted into strain-derived damage images through threshold-based staging that encodes discrete damage states. Structural parameters are concatenated to the damage image by adding fixed-value columns so the network can read structural context in a single two-dimensional input. We design systematic comparisons to isolate the benefit of structural information and section coverage. First, models without structural parameters are trained. Second, single-parameter variants are trained where only one attribute is provided. Third, full-parameter models include all attributes. For each setting, both single-section and multi-section inputs are evaluated. Samples are split by case and then divided 80/20 into training and validation sets. Model performance is reported using RMSE, MAE, and R-squared. The proposed approach achieves accurate inter-story drift ratio prediction overall, with improved performance when all structural parameters and multi-section inputs are used.

This study examines the deformation and stress characteristics of an aerospace turbine wheel under centrifugal, thermal and pressure loads. Design modification is focused on the neck of the disk, which is a structurally critical area. Increasing the neck thickness significantly reduces radial deformation from centrifugal force, while thermal and pressure-induced deformations remain nearly unchanged. Stress at the blade root is minimally affected by geometric changes, but the disk neck stresses decrease notably when the radius is between 3.25 and 4.00 mm. Beyond 4.00 mm, stress rises again due to a shift in the peak stress location to the rear side. Yielding is first observed at a 3.5 mm radius, where deformation is also reduced to 0.29 mm. This geometry thus offers the best balance between strength and deformation. The findings provide a method to determine optimal neck design for prescribed design conditions.

지하 매설 수도관은 연약지반의 지반침하, 도심지의 부등침하, 싱크홀 등에 의한 허용한계를 초과하는 지반영구변형에 의해 손상이 발생할 수 있다. 지반변형으로부터 수도관을 보호하기 위한 관이음의 사용으로 수도시설의 안전성 확보가 요구된다. 따라서 매립 수도관의 과도 지반변형에 대한 안전성 평가를 위하여 다중적층형 벨로우즈를 신축관 이음으로 적용한 수도 배관시스템을 제작하 였다. 제작된 배관시스템의 굽힘 및 처짐에 대한 변형 성능 확인을 위하여 4점 굽힘 시험을 수행하였다. 4점 굽힘 시험 결과를 바탕으 로 국내 연약지반 모델을 고려하여 KS D ISO 16134에 따라 지반변형에 대한 안전성을 평가하였다. 안전성 평가 결과 다중적층형 벨로우즈 신축관 이음의 지반변형에 대한 성능은 매우 우수한 것으로 평가되었다.

In this study, the shape of the exterior, not the inside of the product, was modified. Various exterior shape change plans were compared and reviewed through injection molding analysis, and among them, the most effective shape for suppressing warpage deformation was derived. The shape of the product was modified to optimize the bending deformation of the cover located at the top of the automobile battery case. The analysis was conducted under a total of three conditions, each of shape A, which is a rectangular parallelepiped shape at the top of the product, and shape B, which is concave on the side of the product. As a result of the study, both shape A and shape B were reduced compared to the amount of bending deformation of the original shape. Among them, shape B2, which showed the largest reduction, decreased by 82.096% from the amount of bending deformation of the original shape.

There have been meaningful changes in column stirrup spacing by KDS 41 20 00 in 2022, which is to decrease one of the spacing limits from the minimum section dimension to half of the minimum section dimension. Decreased column stirrup spacing increases the seismic shear resistance of columns and the seismic performance of the entire building. Among the effects of the column stirrup spacing change, this study focused on deformation compatibility in the seismic design of building frame system buildings with ordinary shear walls for seismic design category D. The beams and columns in building frame systems shall satisfy moment and shear strength, or deformation capability induced by seismic design displacement for satisfaction of the deformation compatibility. The commentary of KDS 41 17 00 describes that the deformation compatibility check can be ignored if the members in moment frames are upgraded to intermediate section details. The study showed that the deformation compatibility of columns was satisfied without additional consideration if the building frame systems were designed by the decreased column spacing in KDS 41 20 00. However, beams adjacent to walls needed further consideration, such as the recommendation of commentary in the code.

This study examined how 16 Chinese transformational structures are generated using generative AI from the perspective of learners whose native language is Korean. To summarize: (1) In weak AI models, using the zero-shot input method, Baidu generated 13 transformed Chinese Sentences, and Papago generated 11 transformed Chinese Sentences. (2) In strong AI models, using the prompt input method, WRTN generated 12 transformed Chinese Sentences, and Yuanbao generated 11 transformed Chinese Sentences. The possible reason why weak AI showed better results than strong AI may be because the analysis target was simple sentences. Baidu and Papago AI are programs specialized in translation. Therefore, under the same conditions as the experiment, it can posited that weak AI is more specialized than strong AI. Thus, it may be sufficient to utilize weak AI in current Chinese writing education. Nevertheless, for this research be applicable to Chinese writing education, the following additional analyses are necessary: (1) This study targeted ‘simple sentences.’ If applied to ‘complex sentence’ writing education, an analysis of whether weak AI remains useful is necessary. (2) An analysis of how to conduct education using Artificial Intelligence is required.

본 연구는 DNVGL-CG-0127 및 통합공통구조규칙(H-CSR)이 적용된 유한요소해석(FEA)을 통해 검증된, 기존 드라이도킹의 지 속 가능한 대안으로서 안벽 부유식 구조 보수의 타당성을 연구하였다. 정수압 하중을 받는 75K 제품 운반선의 전역 및 국소 거동을 시뮬레이션하여, 보수가 필요한 무시할 수 있는 변위 변화(<1%, 12.3mm~12.4mm)와 von-Mises 응력(26.4MPa, 허용 한계값 188MPa의 14%) 에서, 구조적 무결성을 확인했다. 최적화된 보수 설계는 고강도 해양 등급 강재(예: AH36)와 하위 모델링 기법을 활용하여 Saint-Venant 의 원리와 선형 탄성 가정을 준수하면서 기하학적 불연속점의 응력 집중을 해결하였다. 선급 지침을 준수하면 유체역학적 안정성과 하 중 경로 충실도가 보장되어 선박 운항 중단을 최소화할 수 있습니다. 본 연구 결과는 비용 효율적이고 시간 효율적인 유지보수로의 패 러다임 전환을 보여주며, 기존 방식 대비 가동 중단 시간을 최대 30% 단축합니다. 향후 추진 방향에는 동적 하중 하의 피로 분석, AI 기반 최적화, 그리고 실시간 구조 건전성 모니터링을 위한 디지털 트윈 통합이 포함되며, 이는 해양 탈탄소화 및 운영 민첩성 목표 달 성에 부합한다. 본 연구는 노후화된 선박의 성능 개선을 위한 확장 가능한 프레임워크를 제공하며, 계산 정밀도와 지속가능성에 대한 업계의 요구를 충족한다.

본 연구에서는 EBR 및 EBROG 기법으로 부착된 CFRP판과 콘크리트 모체 간 부착성능을 평가하였다. 실험 변수로는 콘크리 트 압축강도, 홈의 개수 및 깊이를 고려하였으며, 총 21개의 시편을 대상으로 단일 랩 전단 실험을 수행하였다. 실험 결과, EBROG 기법을 적용한 시편은 EBR 기법을 적용한 시편보다 최대 62% 높은 부착 강도를 보였다. 또한, 홈의 개수와 깊이가 증가할수록 부착강 도도 증가했으나, 홈이 3개일 때 가장 높은 증가율을 기록하였다. 한편, 콘크리트 압축강도가 증가할수록 부착강도도 상승했지만, 압축 강도가 가장 높은 시편에서는 오히려 부착강도 증가율이 가장 낮았다. 아울러, EBROG 기법으로 부착된 CFRP 판의 유효 변형률을 예측하는 모델을 개발하기 위해 실험 데이터를 기반으로 회귀 분석을 수행하였다. 제안된 모델의 예측값과 실험값의 비의 평균과 표준 편차는 각각 1.002 및 0.032로 나타나, 해당 모델이 유효 변형률을 정확하게 예측할 수 있음을 확인하였다.