In apartment buildings in Korea, irregular walls, such as T-, L-, and U-shaped walls, are commonly used. However, in practical design, the geometric irregularities of walls are often neglected when determining the length of the lateral confinement region. Further, although earthquake loads apply from various directions, the lateral confinement region is typically determined for the in-plane direction of the web. Thus, using finite element analysis, this study investigated the structural performance of irregular walls subjected to various loading directions. As the design parameters, wall shape, cross-sectional aspect ratio, and loading direction were addressed. According to the parametric analysis results, as the length of flange in tension increased, the lateral confinement region should be evaluated with consideration of the geometric irregularity. Further, for the L- and U-shaped walls, it is recommended to evaluate the lateral confinement region for various loading directions. Based on these results, a design method to determine the lateral confinement region of irregular walls was suggested.

The number of significant issues on many welding processes are often connected to high productivity and manufacturability at low costs. The research on welding processes in the literature has reported several research activities, but there is still scope for improvement in most industrial settings. The primary goal of this research is to determine the best super-TIG welding settings to use for groove welding. First, in order to determine the quality characteristics and risks associated with them, concepts and frameworks of quality by design (QbD) which is a new standard in pharmaceutical area in order to improve drug qualities were integrated into this process optimization. Second, stepwise experimental design approaches including a factorial design as well as a response surface methodology (RSM) were customized and performed for this specific automated super-TIG welding process. Third, based on experimental design results, the optimal operating conditions with both design space (i.e., acceptable range of operating conditions) and safe operating space (i.e., safe range of operating conditions) were obtained. Finally, a case study including QbD steps, stepwise experimental design approaches, design and operating spaces, the optimal factor settings, and their association validation results was conducted for verification purposes.

Reinforcement learning (RL) is successfully applied to various engineering fields. RL is generally used for structural control cases to develop the control algorithms. On the other hand, a machine learning (ML) is adopted in various research to make automated structural design model for reinforced concrete (RC) beam members. In this case, ML models are developed to produce results that are as similar to those of training data as possible. The ML model developed in this way is difficult to produce better results than the training data. However, in reinforcement learning, an agent learns to make decisions by interacting with an environment. Therefore, the RL agent can find better design solution than the training data. In the structural design process (environment), the action of RL agent represent design variables of RC beam. Because the number of design variables of RC beam section is many, multi-agent DQN (Deep Q-Network) was used in this study to effectively find the optimal design solution. Among various versions of DQN, Double Q-Learning (DDQN) that not only improves accuracy in estimating the action-values but also improves the policy learned was used in this study. American Concrete Institute (318) was selected as the design codes for optimal structural design of RC beam and it was used to train the RL model without any hand-labeled dataset. Six agents of DDQN provides actions for beam with, beam depth, bottom rebar size, number of bottom rebar, top rebar size, and shear stirrup size, respectively. Six agents of DDQN were trained for 5,000 episodes and the performance of the multi-agent of DDQN was evaluated with 100 test design cases that is not used for training. Based on this study, it can be seen that the multi-agent RL algorithm can provide successfully structural design results of doubly reinforced beam.

한국형 포장설계법(KPRP)은 한국의 기후, 교통, 재료 조건을 반영하여 개발된 포장설계법으로, 성능 기반 분석과 역학적-경험적 원 리를 결합하여 국내 도로포장의 내구성과 효율성 향상에 기여해왔다. KPRP는 지역별 환경 데이터, 교통 하중, 재료 특성을 고려하 여 최적의 포장 구조를 설계하며, 2011년 개발 이후 도로포장의 수명 연장과 경제성 향상을 이루어냈다. 그러나 KPRP에 적용되는 기후 및 교통 데이터는 2000년대 초반의 자료를 기반으로 하고 있어, 현재 기준으로 약 10년 이상의 차이가 존재한다. 이에 따라 최 신 데이터를 반영하여 포장설계를 개선할 필요성이 제기되고 있다. 본 연구에서는 최근 10년간의 최신 기후 데이터를 활용하여 줄눈 콘크리트 포장(JCP)의 콘크리트 슬래브 컬링 시간을 계산하고, 이를 기반으로 온도응력 및 교통응력의 산정 방식을 현 시점에 맞게 개선하고자 한다. 또한, 2023년 도로포장관리시스템(PMS) 데이 터를 이용하여 한국도로공사가 관리하는 모든 고속국도 중 JCP가 적용된 구간을 대상으로 표면 균열(SD), 설계 차로별 AADT, 관 리구간별 도로 연장, 차로 폭 등의 데이터를 분석하였다. 이를 통해 각 도로의 피로균열율을 산정하고, 고속국도를 대상으로 줄눈 콘 크리트 포장의 전이함수를 개선하여 보다 정밀한 설계를 가능하게 하고자 한다. 본 연구는 최신 기후 및 교통 데이터를 반영한 KPRP 기반 줄눈 콘크리트 포장설계의 실현에 기여할 것으로 기대된다.

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 demand for secondary batteries is increasing rapidly with the popularization of electric vehicles and the expansion of wireless electronic devices. However, the most widely used lithium-ion batteries are subject to frequent fire incidents, limiting market growth. To avoid flammability, solid electrolyte-based systems are gaining attention for next-generation lithium-ion batteries. However, challenges such as limitations in ionic conductivity and high manufacturing costs require further research and development. In this study, we aim to identify a new nitrogen-based solid electrolyte material that has not yet been widely explored. We propose a methodology for selecting the final material through high-throughput screening (HTS), detailing the methods used for material selection and performance evaluation. In addition, we present ab initio molecular dynamics (AIMD) calculations and results for nitrogen-substituted materials with carbon and oxygen replacements, including Arrhenius plots, activation energy, and the predicted conductivity at 300K for the material with the highest Li-ion conductivity. While the performance does not yet surpass the ionic conductivity and activity of conventional solid-state electrolytes, our results provide a systematic framework for exploring and screening new solid electrolyte materials. This methodology can also be applied to the exploration of different battery materials and is expected to contribute significantly to the innovation of next-generation energy storage technologies.

해상 운송 시스템에 사이버 위협이 증가함에 따라, 안전한 운항을 보장하기 위한 사이버 복원력의 필요성이 부각되고 있다. 특 히, 자율운항선박과 같은 고도의 기술 융합이 요구되는 스마트선박은 기존보다 더 광범위한 사이버 공격 표면을 가지게 되어 이에 대한 리스크 관리가 필수적이다. 본 연구에서는 스마트선박의 사이버 복원력을 평가하기 위해 국제 표준인 IACS UR E26, E27, IEC 62443, NIST SP 800-160을 분석하고, 이를 통해 스마트선박의 선종과 자율화 수준에 따른 사이버 리스크 평가 및 각각의 리스크에 맞는 복원력 모델 개념을 설계하였다. 특히, 선박의 자율화 수준이 높아질수록 사이버 리스크가 커지므로 이를 반영한 맞춤형 대응 전략을 도출하고 스마트 선박의 사이버 복원력 향상을 위한 성숙도 모델을 제안했다.

Performance-Based Seismic Design (PBSD) is an approach that evaluates how structures will perform under different levels of seismic activity. It focuses on ensuring that buildings not only withstand earthquakes but also meet specific performance objectives, such as minimizing damage or maintaining functionality after the event. Unlike traditional methods, PBSD allows for more tailored, cost-effective designs by considering varying degrees of acceptable damage based on the structure's importance and use. PBSD was introduced in Korea in 2016 to replace elastic design, which is inevitable to over-design to cope with all variables such as earthquakes and winds. When PBSD is applied to the structural design new building, One of the challenges of PBSD is the complexity involved in creating accurate inelastic analysis models. The process requires significant time and effort to analyze the results, as it involves detailed simulations of how structures will behave under seismic stress. Additionally, organizing and interpreting the analysis data to meet performance objectives can be labor-intensive and technically demanding. In order to solve this problem, a post-processor program was developed in this study. A post-processor was developed based on Excel program using Visual Basic for Applications(VBA). Because analysis outputs of Perform-3D, that is a commercial software for structural analysis and design, are very complicated, generation of tables and graphs for report is significant time and effort consuming task. When the developed post-processor is used to make the seismic design report, the required task time is significantly reduced.

본 논문은 전통 수면문(獸面紋)이 현대 시각화 혁신 디자인 에서 어떻게 응용되고 발전할 수 있는지를 탐구하였다. 특히, 수면문의 역사적·문화적 의의, 시각화 혁신 디자인 원칙과 방 법, 그리고 구체적인 사례의 실천을 중점적으로 분석하였다. 연 구 결과, 전통 수면문(獸面紋)은 깊은 역사적 배경과 예술적 가 치를 지니고 있으며, 현대 디자인 방법을 통해 효과적으로 현 대 디자인에 융합될 수 있음을 확인하였다. 본 논문은 형식미, 문화성, 혁신성이라는 세 가지 디자인 원칙을 제안하였으며, 형 태 재구성, 색채 활용, 문화 간 융합 등 혁신적 방법을 정리하 여 전통 문양과 현대적 미학의 유기적 결합을 실현하고자 하였 다. 또한, 문창 제품, 의류, 게임 디자인 등 다양한 분야의 실제 사례를 통해 전통 문화 요소가 현대 디자인에서 계승되고 발전 할 수 있는 경로를 검증하였다. 본 연구를 통해 시각화 혁신 디자인과 연구를 활용하여 전통 수면문(獸面紋)의 계승과 발전 을 촉진하고, 현대인의 미적 요구와 문화적 정체성을 충족시키 는 방법을 모색하고자 한다.

The purpose of this study was to optimize the design of asphalt concrete pavements for Jeju Island by considering the regional characteristics of the island. This study employed an MEPDG program to determine the allowable traffic loads for class 4 vehicles by considering the axle loads, climate, and material properties. Samples of basalt asphalt concrete from Jeju were used to measure the dynamic modulus for material property estimation. The climate input was based on 30-year climate data from Jeju. The thicknesses and moduli of the subgrade, subbase, and asphalt layers were incorporated into the design. The regression-analysis program SPSS was used to develop a regression equation for the overlay design, factoring in the modulus and thickness ratios between the existing and overlay asphalt layers. A pavement-thickness design formula tailored to Jeju's characteristics was derived. An equivalent single-axle load factor (ESALF) formula was developed to facilitate traffic-load estimation for different roads, enabling the easy incorporation of varying traffic volumes into the design. The ESALF formula demonstrated a high correlation with the pavement thickness, subgrade conditions, and axle loads, whereas the pavementthickness design formula exhibited strong correlations with the pavement thickness, subgrade state, thickness ratios, and modulus ratios. The use of basalt aggregates in asphalt concrete pavements provides an economically viable and technically sound solution for Jeju. The proposed design methodology not only reduces costs but also enhances pavement performance and road safety. The developed formulas offer flexibility in adjusting designs based on specific traffic conditions, providing optimal pavement solutions for different road categories.

Recently, high-rise residential buildings in Korea have adopted slender shear walls with irregular section shapes, such as T-shape, H-shape, and C-shape. In the seismic design of the slender shear walls, the transverse reinforcement for lateral confinement should be provided in the boundary elements to increase deformation capacity and subsequent ductility. However, in practice, the irregularity of the shear walls is not adequately considered, and the lateral confinement region is calculated for the rectangular wall segments. This study investigated the proper design method for lateral confinement regions using finite element analysis. The lateral confinement region was considered in analysis for two cases: 1) as a typical rectangular wall segment and 2) as an irregular wall. When the irregularity of the walls was considered, the compression zone depth was increased because the vertical reinforcement in the flange was addressed. The effect of lateral confinement design methods on the structural performance of the walls was directly compared under various design parameters, including the length of the flange, concrete compressive strength, vertical rebar layout, axial load ratio, and loading direction. According to the results of the parametric analysis, the peak strength and deformation capacity could be significantly increased when the lateral confinement region was calculated based on irregularly shaped walls, regardless of the design parameters. In addition, the effective compression zone was located within the lateral confinement region. Thus, it is recommended that the lateral confinement region of T-shaped walls is calculated by addressing the irregularity of the walls.

마비성 패류독소 중독증(paralytic shellfish poisoning; PSP)은 삭시톡신과 그 유사체로 오염된 패류를 섭취했을 때 발생하며, 저림, 구토 등의 증상에서부터 근육 마비와 심각한 경우 호흡 마비로 이어져 사망에 이를 수 있다. 독 성등가계수(toxic equivalency factors; TEFs)는 다양한 마 비성 패류독소의 독성을 표준화하여 위험성을 평가하는 데 사용된다. 마비성 패류독소를 검출하기 위해 사용되던 마우스 생체 실험(mouse bioassay; MBA)에 대한 윤리적 문제가 제기되면서 고성능액체크로마토그래피와 같은 기 기 분석법으로의 전환이 시도되고 있지만, 유사체들의 적절 한 TEF를 설정하기 위해서는 여전히 동물 모델을 통한 생 체 내 독성 데이터가 필수적이다. 본 연구에서는 동물 수를 줄이면서도 신뢰할 수 있는 경구투여 독성 결과를 얻기 위 해 삼단계 반응표면-경로 (three-level RSP) 설계를 사용했다. 인증 표준 물질을 이용하여 각 독소의 초기 용량과 조정 계 수를 결정하고 시험을 진행했으며, STX.2HCl, NeoSTX, dcSTX, GTX1&4, GTX2&3, dcGTX2&3의 반수치사량 (및 TEF) 값은 각각 451.3 (1.00), 306.5 (1.47), 860.9 (0.52), 644.5 (0.70), 915.3 (0.49), 2409.3 (0.19)로 나타났다. 도출된 TEF 값은 2016년 WHO에서 권고한 TEF 값뿐만아니라, 이 전에 보고된 경구 투여 반수치사량을 기반으로 한 TEF 값 과 강한 상관관계를 보였다. 본 연구는 마비성 패류독소 뿐 만 아니라 신규 미관리 해양생물독소에 대해 적절한 TEF를 설정하는 데 있어 삼단계 반응표면경로 설계를 윤리적 우 려와 신뢰할 수 있는 독성 데이터의 필요성 사이에서 효과 적으로 균형을 맞출 수 있는 방법으로 제안한다.

This study was conducted to investigate the proper design of alpha board used to support concrete blocks under high loads. A board height of 50 mm was appropriate to ensure a deflection of 3 mm or less under a load of 5 tons. The trapezoidal shape of the vibration absorbers in the interior of the board reduced the maximum deflection by evenly distributing the deflection across the board width. The height of the board is the most important variable in preventing deflection, and for the same board height, adjusting the thickness of the top and bottom plates was more effective in reducing the amount of deflection than adjusting the thickness of the stiffener. The theoretical solution is a good tool for easily predicting the deflection of the board, as it shows a difference of 5 to 15% from the simulation results. However, as a 2D prediction model, the theoretical solution cannot represent the distribution of deflection over the entire board area, so the 3D simulations are necessary in predicting the amount of deflection over the entire board.

본 논문에서는 15차 bézier 곡선을 사용하여 기존의 연구보다 더 유연한 빔 형상을 설계하고, 더 넓은 설계 공간에서 최적 설계를 수 행하여 최적의 열전도도를 갖는 빔 형상을 설계한다. 설계 공간이 넓어지면 그 만큼 계산양이 증가하게 되는데, 고차원 변수 공간에서 효율적으로 작동하는 인공신경망을 사용하여 최적 설계를 가속화하여 계산 한계를 극복하였다. 더 나아가 최적의 탄성계수를 갖는 빔의 형상과 비교하였으며 열전도와 탄성학 사이의 수학적 유사성을 이용하여 빔 형상을 설명한다. 본 연구에서는 인공지능을 활용 한 형상 최적설계를 통해 기존의 한계를 뛰어넘는 격자구조의 빔 형상을 제안한다. 먼저, SC(Simple Cubic), BC(Body Centered Cubic) 격자 구조 빔 형상을 bézier 곡선으로 모델링하고 bézier 곡선의 제어점 좌표를 무작위로 설정하여 학습데이터를 확보하였다. NN(Neural Network) 및 GA(Genetic Algorithm)를 통해 우수한 유효 열전도도를 가진 빔 형상을 생성하여 최적의 빔 형상을 설계하였 다. 본 연구를 통해 추후 다양한 열 조건에서 격자구조의 적절한 구조적 해답을 제시할 수 있을 것으로 기대된다.

CRCP(Continuously Reinforced Cement Pavement)는 시멘트 콘크리트 포장 공법 중 하나이다. 한국형 포장 설계법(KPRP: Korean Pavement Research Program)은 국내 실정에 맞게 개발된 도로 포장 설계법으로, 2011년에 최초로 개발되었다. 현재 최신 버전은 2016년 4월에 발표된 것으로, 이후 약 8년간 업데이트가 이루어지지 않았다. 본 연구의 목적은 한국형 포장 설계법 내 기존 CRCP 해 석 모듈을 분석하고 이를 개선하는 것이다. 또한, 본 연구에서 개선된 CRCP 해석 모듈은 추후 개발 예정인 고속도로 역학적-경험적 설계법(EXPD: EXpressway Pavement Design)에 적용될 예정이다. 문헌 조사를 통해 한국형 포장 설계법의 설계 매뉴얼인 국토교통 부의 도로포장 구조 설계요령(2015)과 TxCRCP-ME의 설계 매뉴얼인 Texas Tech University의 Develop Mechanistic-Empirical Design for CRCP(Soojun Ha 외, 2012)의 내용이 유사함을 확인하였다. 또한, 한국형 포장 설계법 내 기존 CRCP 해석 모듈이 Texas Tech University에서 개발한 역학적-경험적 설계 포장 프로그램인 TxCRCP-ME와 유사함을 확인하였다. 그러나, 휨강도, 탄성계수, 함수비, 복합지지력 K값, 허용하중반복횟수 등 사용자가 입력한 값에 기반한 계산 과정과 공용성 해석에서 기존 KPRP의 CRCP 해석 모듈이 설계 매뉴얼인 국토교통부의 도로포장 구조 설계요령(2015)과 차이점을 보였다. 이러한 분석을 토대로, 추후 개발 예정인 EXPD-CRCP는 기존 KPRP에서 설계 매뉴얼과 상이한 부분을 국토교통부의 도로포장 구조 설계요령(2015)을 준수하여 국내 실정에 적합한 역학적-경험적 설계법으로 개선하고자 한다.