Fixed parameters in metaheuristics like Differential evolution (DE) limit truss optimization efficiency. This study proposes a PS-QDE(Phased strategy Q-Learning DE) algorithm that uses Q-learning to dynamically adapt parameters. A novel "Strategy switching factor" is also introduced to adjust the exploration-exploitation balance based on convergence. The PS-QDE algorithm was validated on four truss optimization problems (10-bar to 200-bar) with frequency constraints. Results show PS-QDE provides more stable convergence and superior or competitive optimal solutions compared to standard DE.

본 연구는 연안해역에서 발생하는 소형선박의 전복ㆍ침몰 사고에 영향을 미치는 복합적 위험 요인을 규명하기 위해 데이 터 기반의 베이지안 네트워크 모델을 구축하고 시나리오 분석을 수행하였다. 분석 결과, 소형선박의 전복ㆍ침몰 사고는 단순한 기상 악화보다는 해역과 교통량의 직접적인 영향을 받는 것으로 나타났다. 특히 민감도 및 사후 확률 추론 결과, 파고가 잔잔한 양호한 기 상 조건이더라도 연안 앞바다에 교통량이 증가할 경우 사고 발생 확률이 기본 4%에서 최대 55.6%까지 증가함을 확인하였다. 본 연구 는 소형선박 전복ㆍ침몰 사고를 교통환경, 해양기상 및 공간적인 요인의 관계를 확률로 계산하여 해석하고 해역 단위 안전관리에서 활용 가능한 정량적인 자료를 제시한 점에서 의의가 있다.

Unapproved parts are increasingly used in military aircraft due to part obsolescence, urgent operational needs, and domestic localization efforts. While such parts may offer short-term flexibility, they pose serious challenges to the integrity of airworthiness certification systems, which rely on part conformity, traceability, and validated performance data. This study identifies and classifies the key risks associated with unapproved parts and applies structured risk assessment tools—Failure Mode and Effects Analysis (FMEA) and the Bow-Tie Risk Model—to quantify and visualize potential failures. Risk elements such as functional mismatch, lack of traceability, and insufficient certification data are prioritized using the Risk Priority Number (RPN) metric. Additionally, the study proposes institutional improvements such as digital traceability systems, conditional approval frameworks, and shared certification databases to mitigate these risks. The findings contribute to enhancing both the safety and flexibility of the airworthiness certification process, particularly in contexts where non-standard parts cannot be avoided. This research offers a practical approach for integrating risk-based thinking into component approval, providing a framework that balances operational demands with safety assurance.

This study aims to refine the existing shear strength model for reinforced concrete(RC) beam–column connections by explicitly incorporating the bi-directional loading effect, which more accurately reflects the actual loading conditions of RC structures during earthquakes. A new database consisting of 21 RC beam–column connection specimens tested under simultaneous bi-directional loading was collected and analyzed to investigate the influence of key parameters on joint shear strength. The results revealed that the joint configuration and the presence of a slab are the primary factors governing the extent of bi-directional loading effect on joint shear strength. Based on these findings, a set of simple and practical modification factors was proposed to refine the existing joint shear strength model to account for bi-directional loading effect. The outcomes of this study provide a rational basis for incorporating bi-directional loading effect into the shear strength evaluation of RC beam–column connections

This study aims to compare and analyze the characteristics of risk reflected by potential risks based on crash modification factors and actual crash risk based on observed accident data at the homogeneous segment level for all general national highways in the Seoul metropolitan area. Conventional road safety evaluations mainly rely on observed crash data, such as crash frequency and rates; however, this approach has limitations in reliably estimating the risk for segments with low crash frequencies or no recorded crashes. To address this limitation, this study estimated the potential risk using crash modification factors that quantified the effects of roadway geometric design and environmental characteristics on crash occurrence, and the actual crash risk was calculated based on severe injury crashes over a recent three-year period. The analysis results indicate that the rank correlation between the potential and actual crash risks is very low, and the agreement rate between the two risk grades is also limited. In particular, segments with low traffic volumes tend to show a high potential risk owing to their structural vulnerability, whereas their actual crash risk remains relatively low. These findings suggest that potential both measures represent different dimensions of roadway safety and must be interpreted in a complementary manner. This study contributes to overcoming the limitations of single-indicator crash-based safety evaluations and provides an analytical basis for comprehensively understanding both the structural roadway and observed crash risks.

Based on a carbon emission inventory of China’s cement industry, this study evaluates the performance of six machine learning models—ridge regression (RR), polynomial regression (PR), random forest (RF), support vector machine (SVR), gradient boosted regression tree (GBRT), and feed-forward neural network (FNN)—in predicting carbon emissions. Model accuracy, feature importance, and residual distributions were analyzed. Results show that clinker production and coal consumption are the dominant factors, contributing 83.7% and 11.95% to emissions, respectively. PR and FNN achieved the best performance with R2 values up to 0.99 and lowest mean square errors (0.11 and 1.82). Their mechanisms were further adapted to improve the generalization of other models. Spatial analysis revealed that North, South, and Southwest China are major emission regions. Using the optimal model, emissions in 2035 are projected to reach 519.14 million tonnes. This study offers technical insights for model optimization and supports low-carbon policymaking in the cement industry.

목적: 본 연구는 백내장 수술 후 안축장 길이(axial length, AL)의 변화가 예측 굴절 도수에 영향을 줄 수 있음을 확인하고, 기존 인공수정체 도수 계산식에 적용되던 보정계수의 정확성에 관해 연구하고자 한다. 방법 : 2022년 3월부터 2025년 7월까지 백내장 수술을 받은 80안을 대상으로 후향적 분석을 시행하였다. 안축 장 길이는 IOL-Master 700 (Carl Zeiss, Germany)을 이용하여 수술 전, 수술 후 1일, 7일, 1개월, 3개월에 각 각 측정하였고, 수술 전과 수술 후 3개월 시점의 안축장 길이 차이는 대응표본 t-검정을 통해 비교하였으며, 수술 전 목표 굴절력과 수술 후 3개월째 실제 굴절력은 단일 표본으로 분석하였다. 또한 기존 인공수정체 굴절 공식에 보정계수를 적용하여 실제 굴절변화량과 비교 분석하였다. 결과 : 수술 전 평균 안축장은 23.86±1.61 mm, 수술 3개월 후는 23.76±1.60 mm로 나타났으며, 평균 0.10 mm의 단축을 보였다(p<0.050). 굴절 예측오차의 평균값은 +0.25±0.28 D로 원시화 경향을 나타냈는데, 이는 안 축장 길이가 단축된 만큼 굴절 도수의 변화가 있음을 보여준다. 보정계수를 실제 인공수정체 공식인 SRK/T에 적 용하여 비교하였을 때, 보정계수 적용 전, 후 인공수정체 굴절 도수 변화량은 +0.62 D가 차이가 났으며, 그에 따른 예측 굴절 도수는 약 –0.41 D 정도로 근시화를 보였다 결론 : 백내장 수술 후 안축장 길이는 단축됨을 보였고, 굴절력 역시 안축장의 변화만큼 원시 방향으로 나타났 다. 본 연구에서 제안한 보정계수를 적용하면 인공수정체 도수 계산식의 정밀한 보정에 기초 자료로 활용될 수 있 을 것이다.

Inflammation is a fundamental host defense mechanism against external insults; however, excessive immune activation contributes to inflammatory diseases such as periodontitis, resulting in periodontal tissue destruction and tooth loss. Interleukin-1β (IL-1β), a key pro-inflammatory cytokine, stimulates oral epithelial cells to produce interleukin-8 (IL-8), which recruits neutrophils and amplifies local inflammation. Therefore, regulation of IL-1β– induced IL-8 secretion in oral epithelial cells is critical for controlling pathological inflammatory responses. Peptidebased therapeutics have attracted increasing interest due to their specificity and biocompatibility, highlighting their potential as anti-inflammatory agents. This study investigated the anti-inflammatory effects and mechanisms of a human stromal cell–derived factor-1 (SDF-1)–derived peptide in IL-1β–stimulated oral epithelial cells. Human oral epithelial KB cells and immortalized human oral keratinocytes were treated with IL-1β in the presence or absence of SDF-1–derived peptides. IL-8 secretion was measured by enzyme-linked immunosorbent assay, and activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) pathways was examined by western blotting. IL-1β significantly increased IL-8 secretion and induced phosphorylation of NF-κB p65 and MAPKs, including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase, and p38. Inhibition of ERK and p38 markedly reduced IL-8 expression, indicating their central roles in IL-1β signaling. Among 18 SDF-1δ–derived peptides, S12 exerted the strongest inhibitory effect, reducing IL-8 secretion and suppressing IL- 1β–induced NF-κB and MAPK phosphorylation. These results demonstrate that S12 attenuates IL-1β–driven IL-8 production by targeting key inflammatory signaling pathways, supporting its potential as a host-modulation therapeutic for periodontal disease.

Using highway accident data, this study predicts the probability of rollover, overturning, and fire accidents and identifies the related risk factors. Whereas existing studies rely primarily on limited explanatory variables and classical statistical models, this study simultaneously enhances predictive performance and interpretability by applying and comparing machine learning-based nonlinear prediction-analysis systems (XGBoost and Shapley additive explanations) with logistic regression, which offers advantages in statistical reasoning. The analysis identifies speeding, segment characteristics (tunnel, ramp, shoulder), and vehicle type (SUV, truck, trailer, and tank lorry) as common key risk factors. These results suggest the necessity of establishing a multilayered management system for speeding, improving facilities centered on high-risk sections (tunnel in/out, ramp, and downhill), performing custom inspections for each vehicle type (load, tire, and brake system), and improving driving behavior (enhancing forward attention, introducing a drowsiness warning system, etc.). This study provides a datadriven empirical basis for identifying the causes of major highway accidents and for designing effective prevention policies.

This study evaluates environmental impact factor emissions generated by three concrete-pavement methods. Specifically, internationally commercialized programs are used to calculate the environmental impact factors of selected domestic concrete-pavement projects, thereby identifying areas requiring improvement. This study quantified the material usage and energy consumption associated with the construction and maintenance of three concrete-pavement methods. Using internationally commercialized software, this study evaluated the emissions of environmental impact factors for jointed concrete, continuously reinforced concrete, and mechanized continuously reinforced concrete pavements under three assumed maintenance scenarios for each method. Analysis of the environmental impact factors over a 30-year period under three maintenance scenarios (Cases A, B, and C) shows that, for the three pavement methods, the construction phase is dominant— constituting 70%–99%—across most impact categories, including global warming, smog formation, acidification, eutrophication, human toxicity, ecological toxicity, and respiratory effects. This study analyzes the environmental impact factors during the construction and maintenance processes of three concrete-pavement types using foreign LCI databases and identifies the environmental impacts of each input material. In the future, if LCI and LCIA databases for domestic road pavement materials are established and analyses are conducted based on the conditions presented in this study, then a foundation can be realized for the development of environmentally friendly materials and methods.

본 연구에서는 사회과학적 문학작품 분석모델을 적용하여 한강의 『소 년이 온다』(2014)에 나타난 존엄 훼손과 회복의 서사, 죽음의 공간적·상 징적 구조, 그리고 죽음의 가치와 사회적·윤리적 죽음담론을 확장시킬 수 있는 청년의 좋은 죽음에 대한 인식의 직·간접적 사례를 깊이 있게 탐구 하였다. 이 작품에서 삶의 마지막 공간은 단순한 임종의 장소가 아니라, 청년의 자기정체성과 존엄 회복의 서사적 공간으로 기능한다. 또한 작품 속 청년의 죽음은 국가폭력과 사회적 침묵 속에서 인간의 존재 가치가 체계적으로 파괴되는 존엄 훼손의 과정으로 재현되지만, 이들의 죽음을 기억하고 재서사화하는 행위를 통해 존엄의 복원과 사회적 연대의 가능 성이 드러난다. 이러한 결과를 근거로 청년세대의 죽음에 대한 인식을 존 엄의 윤리와 사회적 기억의 관점에서 재조명함으로써 현대사회의 죽음담 론이 나아가야 할 방향을 논의하였다.

Human dermal fibroblasts (HDFs) are critical for maintaining skin integrity and facilitating tissue repair, but are highly susceptible to apoptosis and impaired migration under inflammatory stress. Adipose-derived stem cells (ADSCs) exert regenerative effects primarily through paracrine signals, including exosomes enriched with trophic factors. In this study, we investigated the dual role of ADSC-derived exosomal hepatocyte growth factor (HGF) in regulating fibroblast apoptosis and migration under T cell-mediated inflammatory conditions. Co-culture of HDFs with activated Jurkat cells significantly increased apoptosis and inflammatory cytokine production, while treatment with ADSC-derived exosomes reduced apoptosis and enhanced fibroblast migration in a dose-dependent manner. Exosomal markers (CD9, CD63, TSG-101) were confirmed by Western blot, and enzyme-linked immunosorbent assay revealed time-dependent increases in HGF, insulin-like growth factor-1, fibroblast growth factor-2, and transforming growth factor-beta secretion following exosome treatment. Knockdown of HGF using siRNA abolished both the anti-apoptotic and pro-migratory effects of exosomes. Mechanistically, exosomal HGF selectively activated AKT phosphorylation in apoptotic regulation and induced FAK (Tyr397) phosphorylation and MMP-2 expression in migration. These findings suggest that exosomal HGF from ADSCs serves as a central mediator in promoting fibroblast survival and motility via the AKT-FAK axis, and may be a promising candidate for cell-free regenerative therapies targeting immune-mediated skin damage.

Visfatin, an adipokine secreted by cells, is crucial for intracellular nicotinamide adenine dinucleotide+ biosynthesis. Extracellularly, visfatin plays diverse roles in inflammatory conditions, including obesity, which is closely linked to osteoclastogenesis. We previously showed that visfatin enhances receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis in bone marrow-derived macrophages. However, its enzymatic activity during this process is poorly understood. Here, we investigated visfatin’s effects on RANKL-induced osteoclast differentiation. Our results demonstrate that visfatin promotes this differentiation, an effect inhibited by FK866, an inhibitor of visfatin’s enzymatic activity. Furthermore, FK866 also inhibited RANKL-induced osteoclast differentiation. These findings suggest that inhibiting visfatin’s enzymatic activity modulates osteoclast differentiation. Thus, visfatin plays an important role in osteoclastogenesis, both intracellularly and extracellularly, and FK866 has therapeutic potential for diseases characterized by imbalanced osteoclast formation, such as osteoporosis and periodontitis.

본 연구에서는 요리사이자 저자인 마이클 헵이 2018년에 발표한 『사 랑하는 사람과 저녁 식탁에서 죽음을 이야기합시다』의 경험적 이야기를 통해 가족의 긍정적 죽음문화를 강화시킬 수 있는 좋은 죽음에 대한 인 식의 직·간접적 사례를 깊이 있게 탐구하였다. 이 작품은 마이클 헵이 삶 의 가장 소중한 대화로 이끄는 만찬에 초대한 수천 명의 사람들과 죽음 에 관한 대화를 꺼내는 방법, 죽음의 만찬을 할 때마다 감사를 연습하는 과정, 식사라는 매개를 활용하여 죽음을 논의할 때 감정적으로 안전하게 끝내는 방법을 파악하면서 죽음에 관한 대화의 물꼬를 터나가는 진솔한 삶의 이야기다. 사회과학적 문학작품 사례를 분석한 결과, 좋은 죽음에 대한 인식은 가족의 발달단계마다 죽음에 대한 긍정적인 문화를 강화시켜 줄 수 있는 주요 요인인 것으로 나타났다. 이러한 결과를 근거로 가족의 죽음문화에 대한 강화요인으로서 좋은 죽음에 대한 인식을 확장할 수 있 는 방안을 논의하였다.