This study proposes a hierarchical optimization methodology for two-stage gear systems using Monte Carlo enhanced Genetic Algorithm (MCeGA). The approach integrates reliability-based design with genetic algorithms to overcome the inherent randomness of traditional GA methods. A two-phase optimization framework was developed. The system incorporates Unity engine for real-time 3D visualization and interactive design evaluation. Key design constraints including contact ratio, gear ratio, and meshing conditions were parameterized according to ISO 6336 and AGMA 2101 standards. The proposed framework enables application-specific optimal gear configurations through Pareto analysis and weighted optimization, providing engineers with practical design solutions for various industrial requirements.

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.

In the present numerical study, the optimal design of cooling fans for cooling towers was investigated. The key design variables selected were the pitch angle and twist angle of the cooling fan, with the pitch angle ranging from 0° to 20°, and the twist angle from 0° to 10°. The objective was to develop a cooling fan capable of actively responding to varying operating conditions; to this end, the twist angle was implemented as a variable camber at the blade tip. The analysis results showed that, under identical pitch angle conditions, increasing the twist angle tended to reduce the stall phenomenon of the cooling fan. Optimization was performed using the pitch and twist angles as design variables, and lift, pressure drop and torque as response variables. Under the specified operating conditions, a combination of a 5° pitch angle and a 10° twist angle yielded the best performance.

Five novel miniature bipolar radiofrequency (RF) electrode tips with distinct tip geometries (spherical, flat, square, and 45° angled) were developed to enable high-precision tissue ablation. Performance was evaluated on saline-soaked tissue, ex vivo bovine liver, and porcine muscle under consistent RF power settings. All designs produced highly localized lesions only a few millimeters across, confirming precise ablation with minimal damage to surrounding tissue. Tip geometry influenced ablation efficiency: a 45° angled tip created ~5 mm lesions at lower power (highest efficiency), whereas an ultra-fine 1.0 mm tip produced ~1 mm lesions but required higher power. These results indicate that the new bipolar RF electrodes achieve precise, localized tissue ablation with minimal surrounding tissue damage and show promise for precise lesion removal in minimally invasive surgery.

Background: Pulmonary fibrosis (PF) is a progressive lung disease marked by excessive fibrosis and declining respiratory function. While pharmacological treatments help manage symptoms, they offer limited reversal of fibrosis and often have side effects. As a result, interest in rehabilitation approaches such as breathing exercises combined with self-myofascial release (SMR) has increased. These techniques may enhance trunk stability and thoracic flexibility, contributing to improved respiratory function. Objectives: This study investigated the effects of thoracic expansion exercises using SMR techniques on pulmonary function and chest mobility in a patient with PF, and assessed their clinical applicability. Design: Single-subject A-B-A′ design. Methods: A 60s male with idiopathic PF underwent 20 days of intervention. Standard rehabilitation was applied during baseline (A) and follow-up (A′) phases. During the intervention (B), SMR-based breathing exercises were added. Outcomes included Functional Reach Test (FRT), chest expansion, and pulmonary function tests (FVC, FEV₁, PEF, FEV₁/FVC). Data were analyzed using the 2SD band method. Results: FRT improved from 23.4 cm (A) to 31.3 cm (B) and 34.2 cm (A′). Chest expansion increased from 1.7 cm to 2.8 cm, and FVC rose from 1.70 L to 2.08 L before dropping to 0.94 L. FEV₁/FVC improved from 80.8% to 86.7% during intervention but decreased at follow-up. Conclusion: SMR-based thoracic expansion exercises may enhance trunk stability, thoracic mobility, and certain pulmonary function indicators in PF patients. These findings suggest potential clinical benefits, warranting further studies to confirm long-term effectiveness.

This study proposes a real-time content design pipeline optimized for Unreal Engine, integrating generative AI-based image creation with AI-assisted 3D modeling tools. The pipeline aims to streamline the production of high-quality assets for real-time applications, including games and simulations. Two types of subjects were selected: a bust combining organic character features, and a stone slab characterized by planar and symmetrical structure. Multi-angle image data were first synthesized using advanced generative AI models to simulate diverse viewpoints. These were then processed using AI-enhanced photogrammetry and modeling tools to reconstruct detailed 3D meshes and extract base textures. Post-processing steps, including mesh decimation, UV unwrapping, and texture baking, were performed to ensure compatibility with Physically Based Rendering (PBR) workflows used in Unreal Engine. The final assets were successfully imported into Unreal Engine, demonstrating visual fidelity and performance suitability in a real-time environment. The study confirms the pipeline’s potential for accelerating asset development and suggests promising future directions in AI-driven digital content creation.

In this study, the structural analysis for the compressor wheel of a high-speed rotating turbocharger is presented, and the failure phenomenon that occurred during the durability test is analytically reproduced. Next, in order to set the optimization conditions, the stress for design shape, fastening force, and press-fit condition were analyzed. As a result, the maximum stress in the failure areas increases as the fastening force increases. Therefore, in order to improve the durability of the compressor wheel, the axial force is reduced while applying the press-fit between the wheel and the shaft. Meanwhile, when the shape of the back surface of the wheel was changed, the stress was additionally reduced by approximately 8.5%.

본 연구는 설계변경이 빈번하게 발생하는 민간공사의 단가도급 건축 인테리어 공사에서 각 공사의 기성율에 약정금액을 적용하여 공사대금을 산정하는 공사 대금 감정시, 설계 변경 전의 ‘미시공(제외) 물량’과 기시공 부분의 물량 증감에 대한 공사 내용을 내역서와 공정표를 기반으로 하여 약정금액을 감정인이 임 의로 정하게 되는 경우를 단계별 COST & TIME TABLE분석을 통한 변경약정 금액 적용에 대해 연구한 것이다. 계약 시 또는 공사중 변경 계약된 약정 총공사비를 기준으로 각 공정의 계획물 량과 실적물량을 종합하여 기성율을 산정하고 약정금액을 곱해 기성고 및 추 가공사대금을 산정한다. 기성고 공사대금 산정 시 약정을 우선하고 추가공사대금 약정이 되어 있지 않 더라도 감정 신청에 따라 추가 공사비 약정 존부를 법원에서 최종 결정하기 전 감정인이 추가 공사한 사실을 전제로 감정인이 감정서에 추가공사비의 기성율과 추가공사대금을 산출하게 되는데 각 공사대금의 약정금액은 기시공에 소요된 공사비 이외 설계변경 발생시 미시공(제외)물량과 물량증감, 기시공 중 철거후재시공, 변경시공, 기시공의 하자보수와 지연분석 및 공정표를 함께 고 려해서 최종 약정금액을 적용해야 한다.

This study explores how to integrate the generative artificial intelligence (AI) tool Midjourney into the fashion design process, emphasizing the visualization of sporty fashion concepts. The research applied Midjourney at every stage of the fashion design process: mood board, fashion sketch, flat drawing, production package, fashion show presentation, and store display and sales. Specifically, sporty fashion was selected as the theme, and customized prompts were developed from prior research and design principles to generate visual outputs for each stage. Furthermore, three apparel design experts evaluated the AI-generated images to assess Midjourney’s practical applicability and effectiveness in each phase of the fashion design workflow. Expert evaluations revealed that Midjourney was particularly effective in the early stages, offering diverse and visually engaging imagery that supported creative ideation and mood expression. The tool allowed quick exploration of different silhouettes during the sketching stage but was imprecise in detailed forms and proportions. Limitations became more evident in the flat drawing and work instruction stages, where outputs failed to accurately reflect material textures and technical construction. Prompt refinements and referencebased prompts were tested but often resulted in inconsistent or stylized outputs. Additionally, continuity between stages was missing. Midjourney shows potential as a creative tool, but experts highlight its limitations for practical industry application. Further research is needed to improve prompt optimization and training data for enhanced accuracy and usability in AI-assisted fashion design workflows.

어선은 다른 어선들과 근접 운항하는 경우가 많아 선회 반경이 작고 빠른 방향 전환이 가능해야 한다. 어선은 또한 파도와 조류 의 영향을 많이 받기에 순간적인 조종이 필요한 경우가 많다. 해양교통안전정보시스템에 따르면 10톤 미만의 소형 선박에 대한 사고는 전 체 사고의 69%에 해당하며 접촉, 충돌, 좌초가 주요인인 사고는 낮은 조종성능으로 인한 사고이다. 이에 소형 어선에 대한 조종성능 평가가 필요하다. 본 연구에서는 4.99톤급 소형 어선을 대상선으로 선정하여 CFD 기반 수치해석 프로그램인 STAR-CCM+을 활용하여 주요 제원 변 화에 따른 조종성능 시뮬레이션을 구축하였다. 조종 성능 평가로는 ∘ /∘ zig-zag test, ∘ /∘ zig-zag test, ∘ portside turning test를 진행 하였다. zig-zag test에서는 L/B가 우세한 선형들이 B/D가 우세한 선형들과 Overshoot angle에서는 큰 차이를 보이지 않았지만 빠른 변침 속도 를 보였다. 반대로 Turning test에서는 B/D가 우세한 선형들이 L/B가 우세한 선형들보다 비교적 작은 선회 반경을 보였다. 이를 바탕으로 4.99톤급 어선의 초기설계 단계에서 조종성능을 고려한 주요 제원을 선정할 수 있는 기초자료로 사용될 수 있을 것으로 기대한다.

The purpose of this study is to examine the application and effectiveness of tuned mass dampers for reducing cabinet vibration in plants. Cabinet with lower structural rigidity than plant subject to seismic design standards is susceptible to resonance. SolidWorks was used for 3D modeling of the cabinet, and ANSYS Workbench was used to create a mesh. The vibration characteristics of the cabinet were investigated through modal analysis, and the possibility of resonance and vibration reduction performance of the cabinet were evaluated. The number of modes in the cabinet was set to 100, and the frequency and modal participation mass ratio of each mode were calculated. In order to examine the possibility of vibration reduction by tuned mass dampers, the vibration response characteristics of cabinets with and without tuned mass dampers were compared. The analysis results showed that the third mode had a significant effect on the dynamic behavior of the cabinet and that the modal participation effective mass ratio was larger than that of other vibration modes. And as the mass of the tuned mass damper increased, the vibration response of the cabinet decreased significantly, and the peak value of the cabinet decreased by up to 52%.

Conventional bipolar electrodes (typically with round or flat tips) deliver radiofrequency energy in a broad, continuous manner. Their larger tip size and simple shape cause the applied energy to disperse over a wide area, making precise lesion control difficult and often leading to collateral tissue damage. As a result of these design limitations, traditional electrodes exhibit lower energy efficiency and tend to create lesions that unintentionally extend beyond the target area, with excessive thermal spread to surrounding tissues. In contrast, the five newly developed bipolar electrode designs concentrate energy delivery more effectively and provide improved control over lesion size and shape. These novel electrodes demonstrated higher energy efficiency, produced well-confined lesions, and minimized thermal injury to adjacent tissues, thereby overcoming the major drawbacks of conventional designs.

As the transportation paradigm shifts from vehicle-oriented to pedestrian-oriented, active research has been conducted on road designs that consider the safety of pedestrians, cyclists, and personal mobility users. This study aims to respond to this change by developing installation warrant factors and improving the minimum size design standards for triangular islands. This study involved reviewing domestic and international laws and guidelines, analyzing the current installation status of triangular islands, examining case studies of improvements, and assessing policy changes. Based on the findings, important insights were derived, and improvement plans to enhance the safety of pedestrians, vulnerable users, and other road users were proposed. This study identified several issues and confirmed that policies in both domestic and international contexts are shifting towards minimizing or removing the triangular islands. Based on these findings, this study developed 24 factors for installation warrants to determine the installation of triangular islands, such as the design speed and peak-hour volume for pedestrians. In addition, the proposed improvements suggest increasing the minimum size design standards from 9m2 to 22m2 to ensure the safety of users. The factors of installation warrants and improved minimum size design standards proposed in this study are expected to help shift the operation of triangular islands from a vehicle-oriented to a pedestrian-oriented approach.

Advances in digital tools and building structure technologies have enabled more flexible architectural design, with AI-based performance design gaining considerable attention as a new design methodology. Stadium design must consider the two primary elements of sports events: athletes and spectators. Given that the facade of a stadium directly impacts solar energy efficiency, it is essential to incorporate environmental performance considerations from the initial design phase. This study employs an AI-based Generative Design process to generate a facade form that efficiently manages solar radiation and daylight, satisfying two conflicting performance objectives: max- imizing sunlight for turf growth in the pitch zone and minimizing direct sunlight exposure in the stadium seating zone. The optimal solution derived ranks 331st for pitch zone sunlight and 408th for stadium seating sunlight out of a dataset of 1,000 models. While this solution does not represent the absolute best for either individual objective, it is evaluated as the most balanced alternative, achieving the goal of maximizing sunlight in the pitch zone and minimizing it in the seating zone

최근 팬데믹으로 인해 혼술 및 홈술 문화가 확산되고, 고급 주류에 대한 관심이 증가하면서 온라인 주류 구매 및 픽업 서비스 이용이 활성화되고 있다. 이에 따라, 온라인 주류 앱과 같은 디지털마케팅 채널에서 차별화된 사용자 경험(UX)이 핵심 경쟁 요소로 부각되고 있다. 이러한 상황에서, 본 연구는 디자인씽킹 기반 디지털마케팅 교육과정을 통한 UX 디자인 개선 프로젝트를 진행하여, 주류 앱 ‘데일리샷’의 온라인 주류 구매 경험을 향상시키기 위한 방안 도출 과정을 분석하는 것을 목표로 한다. 본 프로젝트는 디자인씽킹 기반 디지털마케팅 프로세스의 단계적 접 근을 활용하여 진행되었으며, 교육과정의 실습 활동으로 운영되었다. ‘탐색(Discover)’ 및 ‘정의(Define)’ 단계에서는 데스크 리서치를 통해 주류 시장과 소비자 트렌드를 분석하고, 사용자 리서치(사용성 평가, 앱 리뷰 분석, 심층 인터 뷰)를 수행하여 사용자의 니즈를 도출하였다. 연구 결과, 팬데믹 이후 증가한 주류 입문자들을 위한 ‘주류 입문 가이 드’의 필요성이 높아졌으며, 주류 소비가 단순한 음용을 넘어 취향을 공유하고 사회적 상호작용의 수단으로 활용되 고 있음이 확인되었다. 이러한 발견점을 바탕으로 ‘개발(Develop)’ 단계에서 개인화된 주류 추천 기능 강화, 네비게 이션 간소화, 커뮤니티 상호작용 기능 활성화 등의 UX 디자인 개선 방안을 제안하였다. 이를 통해, 데일리샷이 단순 한 주류 픽업 서비스를 넘어, 개인의 주류 취향을 탐색하고 차별화된 구매 경험을 제공할 수 있는 플랫폼으로 발전할 기반을 마련하고자 하였다. 본 연구는 디자인씽킹 기반의 디지털마케팅 프로세스가 주류 앱 UX 디자인 개선에 효과 적인 접근법임을 강조하고, 디자인씽킹을 적용한 디지털마케팅 교육과정이 학생들의 UX 실무 역량 향상에 기여할 수 있음을 보여주었다.