This study investigated the influence of alloying elements on the elastic modulus variation of titanium alloys and conducted theoretical density calculations, yielding the following conclusions. In Ti-M (M=Zr, Ag, Au, and Cu) alloys, the Md value ranges from 2.89325 to 11.1530, and the Bo value ranges from 2.30180 to 3.22978. Ti-Zr alloys are most suitable as optimal dental implant materials in terms of electronic structural stability and strength. Ti–Au and Ti–Ag primarily contribute to biocompatibility, corrosion resistance, and antibacterial performance, while offering less benefit for mechanical strengthening. Ti-Cu, while having low structural stability, exhibits excellent antibacterial functionality and is therefore worthy of consideration as a supplementary alloying element. The physical properties of ‑titanium–based Ti–M binary alloys have been examined, and future research will focus on extending the study to ternary and quaternary titanium alloy systems.

Freshwater ecosystems support biodiversity and provide essential ecosystem services. In Korea, the Water Environment Information System monitors these ecosystems using separate biological and physicochemical indicators. Complex interactions occur among diverse biological taxa and physicochemical conditions. Thus, integrating heterogeneous monitoring data is crucial for accurately assessing ecosystem health. However, differences in data characteristics between the indicators present significant integration challenges. Given the scale and heterogeneity of the monitoring data, advanced analytical techniques are necessary to detect interactions among variables. This study aimed to identify key correlations among biological and physicochemical indicators by clustering similar variables and removing noise using the Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN) algorithm, followed by Spearman’s rank correlation coefficient and maximal information coefficient (MIC) analyses. HDBSCAN effectively eliminated noise indicators and grouped biological and physicochemical indicators into clusters based on shared characteristics, thereby enhancing the interpretability of the correlation analysis. Spearman analysis showed strong associations among biological indicators, particularly among species with similar ecological traits. MIC analysis further detected nonlinear associations between ecological assessment indices and specific biological species, which also reflected similar ecological characteristics. These findings are significant in that the comprehensive analysis of existing monitoring data revealed relationships within biological and physicochemical indicators while preserving the original purpose and function of each monitoring network. This study is expected to serve as a foundational resource for freshwater environmental monitoring and the development of effective management strategies.

목적 : 본 연구의 목적은 HMD 기반 가상현실을 사용할 때 나타나는 사이버 멀미를 분석하기 위해 VR 사용 전후 안정뇌파의 정량적 분석 및 멀미 민감성(MSSQ)과 EEG 상대 파워가 상관관계를 보이는지 알아보고자 하였다. 방법 : 근거리 시력에 이상이 없는 성인 여성 11명을 대상으로 VR 사용 전후 안정상태 뇌파를 건식 전극 헤드 셋(DSI-24)을 사용하여 측정하였으며, 멀미 민감도는 MSSQ 설문을 통해 평가하였다. VR 사용 전후 비교는 Wilcoxon Signed-Rank Test를, 뇌파 변화량과 멀미 민감성 상관관계는 Spearman’s correlation analysis, 그 리고 뇌파 상대 파워 변화량(ΔEEG)이 멀미 민감도 집단 간 비교는 Mann-Whitney U Test를 실시하였다. 결과 : VR 사용 후 분석 결과 여러 부위에서 저주파 활동인 세타파(RT)는 일관되게 감소, 세타파 대비 베타파 비율(RMT, RSMT)과 같은 주의 집중 관련 지표는 증가하는 경향을 보였다. EEG 변화와 멀미 민감성 설문 점수 간의 상관분석 결과 측두엽(T6)과 두정엽(Pz) 영역에서 MSSQ와 유의한 상관관계를 확인하였다. 멀미 민감도가 높 은 그룹에서는 감각 통합을 담당하는 두정엽(Pz, P3, P4)영역의 베타파 대역 활성도가 유의하게 감소하였다. 결론 : VR 사용 후 후두엽 부위의 주의 집중 관련 비율 지표 증가는 정보처리과정 중 시각적 자극에 대한 자극 인지 등을 반영하는 것으로 볼 수 있으며, 두정엽과 상반된 결과가 나타난 것을 토대로 VR의 시각 자극과 신체 감 각의 불일치는 사이버 멀미를 유발한다는 근거를 제시한다.

Board games are steadily growing, re-evaluating the value of analog communication in the digital age. This market growth has raised players' expectations for quality, leading to a growing demand for well-crafted, well-balanced games. Game balance is a crucial element in providing players with a fair and immersive experience. However, board game balancing has primarily relied on the designer's experience or intuition, or on small-scale testing, which is time-consuming, costly, and carries the risk of bias. Therefore, this study aimed to empirically analyze the core elements of balance perceived by players. Based on existing research, we derived four balance factors—fairness, variety, scalability, and ease of play—and three play experiences—immersion, aesthetics, and interactivity. We conducted a survey of 78 college students who played eight board games over an eight-week period, and performed correlation and multiple regression analyses. The results revealed that fairness and variety significantly influenced players' immersive experiences. Variety, ease of play, and scalability significantly influenced the aesthetic experience, while expandability and variety had the greatest impact on the interactivity experience. This study is significant in that it leads the discussion on board game balance to data-based empirical analysis and provides objective balance adjustment guidelines to game designers.

목적 : 안경광학과 학생들의 의사소통 역량과 안경사 윤리강령 인식 간의 상관성을 분석하여, 예비 안경사의 핵 심 직무 역량 강화를 위한 교육 프로그램 개발의 기초 자료로 활용하고자 한다. 방법 : 본 연구에서는 안경광학과 재학생 98명을 대상으로 일반적 특성과 교육 경험 및 필요도는 빈도와 백분율 로 분석하였고, 최근 1년간 봉사 경험과 윤리적 가치 의식은 카이제곱 검정(chi-squared test)을 통해 분석하였 다. 또한, 의사소통 역량과 안경사 윤리강령 간의 상관관계는 Pearson 상관분석을 이용하여 분석하였다. 결과 : 의사소통 교육 경험 여부에 대해 77.55%가 경험이 있다고 응답했으며, 직업윤리 교육 경험 여부는 86.73%가 있다고 응답하였다고 답했다. 또한, 의사소통 역량의 필요성에 대해 81.63%가 필요하다고 응답하였다. 직무 관련 최근 1년간 봉사활동 경험과 윤리적 가치 및 직업의식 간의 연관성을 분석한 결과, 봉사 경험과 '우리 사 회의 근면성을 설명할 수 있다'라는 문항 간에 유의한 상관성(χ2=27.91, p=0.032)이 나타났다. 안경사 윤리강령과 의사소통 역량 간의 상관 분석 결과, '안경사는 품위를 유지하고 봉사 정신을 발휘해야 한다'와 '원활한 의사 표현을 방해하는 요인을 설명할 수 있다' 문항 간에 가장 높은 상관성(r=0.71, p<0.001)을 보였다. 결론 : 본 연구에서, 예비 안경사의 의사소통 역량 강화와 정직성을 바탕으로 한 직업윤리 확립의 필요성이 확 인되었다. 봉사 경험과 윤리적 가치 의식, 그리고 의사소통 역량과 안경사 윤리강령 간에 유의한 상관관계는, 다양 한 계층을 대상으로 한 비교과 프로그램을 체계적으로 구축하고 효과적인 교육 시스템 마련의 필요성을 시사한다.

초당옥수수는 고당도 옥수수 품종으로, 식단 트렌드 변화와 천연 당류에 대한 관심 증가로 인해 수요가 증가하면서 재배가 확대되고 있다. 초당옥수수는 높은 당도로 매우 달고 맛이 좋지만, 전분 함량이 낮아 일반 옥수수에 비해 발아율이 낮은 특징이 있다. 본 연구는 초당옥수수 계통의 전분 함량과 발아율의 상관관계를 조사하여, 우수한 생장과 발아율을 갖춘 고품질 계통을 선발하는 것을 목표로 하였다. 본 연구에서는 10개의 초당옥수수 계통을 대상으로 발아율과 식물체 생장 특성을 평가하였다. 모든 계통이 80% 이상의 발아율을 보였으며, KH51 계통이 53일로 가장 출사일이 빨랐고, KH29W 계통이 148cm로 간장이 가장 크게 나타났다. 고당도 계통을 선발하기 위해 수정 후 20일째에 이삭을 수확하여 유리당 함량을 측정하였다. KH28W 계통이 가장 높은 당 함량(23.3%)을 보였으며, KH45 계통이 가장 낮은 당 함량(8.1%)을 나타냈다. 또한, 전분 함량이 유리당과 비례하여 축적되는지를 확인하기 위해 수분 후 40일째에 이삭을 수확하여 분석한 결과, KH47 계통이 가장 높은 전분 함량(30.1%)을, KH28W 계통이 가장 낮은 전분 함량(23.6%)을 보였다. 전분 함량이 발아에 미치는 영향을 평가하기 위해 발아와 관련된 효소 및 유전자들을 분석하여, 발아 과정에서의 효소 활성 및 유전자 발현 수준을 측정하였다. 낮은 전분 함량은 발아 초기에 효소 활성과 유전자 발현을 저하시켜 발아 지연 및 불균일성을 초래하였으나, 발아 후 생장에는 큰 영향을 미치지 않았다. 이는 초당옥수수 종자의 초기 발아 과정이 유리당과 전분 함량에 의해 영향을 받을 수 있음을 시사한다.

목적 : 이 연구는 COVID-19 팬데믹 전후로 중년층에서 근거리 작업 시간이 증가함에 따라 근시 발달에 미치는 영향을 분석하는 데 중점을 두고 있다. 또한, 팬데믹 기간 동안 생활 방식의 변화가 근시 악화에 어떻게 기여했는지도 평가한다. 방법 : 질병관리청 국민건강영양조사 제8기 자료를 기반으로, 2019년과 2021년 동안 수집된 중년층(40~60세) 의 굴절력 데이터를 분석하였다. 성별, 연령, 근거리 작업 시간 등을 포함한 설문조사 데이터를 바탕으로 통계분석 을 수행하였으며, T-test와 카이제곱 검정(χ²)을 통해 두 시기 간 굴절력 변화를 비교하였다. 결과 : 2021년 팬데믹 이후 중년층의 근시가 유의미하게 악화되었으며, 특히 3시간 이상의 근거리 작업 시간이 고도 근시로의 진행을 가속화시키는 것으로 나타났다. 오른쪽 눈의 굴절력 악화가 더 두드러졌으며, 이는 작업 습 관 및 안구 피로와 관련이 있을 수 있다. 결론 : COVID-19 팬데믹 동안 근거리 작업 시간의 급증이 중년층의 근시 진행에 중요한 영향을 미쳤음을 확인 하였다. 향후 중년층의 시력 보호를 위해 실외 활동 증대와 디지털 기기 사용 시간을 줄이는 예방적 조치가 필요하다.

2019년 12월, 상주-영천 고속도로 상행선에서 도로 노면 결빙에 의한 연쇄추돌사고로 48명의 사상자가 발생하였다. 이에, 국토교통부 는 2020년 1월 결빙 취약구간 선정기준을 마련하여 결빙 취약구간 403개소를 지정하고, 결빙 취약구간을 대상으로 2022년까지 1,699억 원의 예산을 투입하여 결빙사고 예방사업을 계획하였다(BAI, 2021). 하지만, 결빙 취약구간 선정기준에 대해 적정성 검토가 이루어지 지 않아 그 신뢰성과 실효성이 충분히 검증되지 않았다. 본 연구에서는 국가교통정보센터의 노드·링크(Node·Link) 체계를 기반으로 전국 고속국도 및 일반국도의 특성정보(시설, 선형구조, 기상, 교통 등)를 GIS(Geographic Information System) 데이터로 구축하였다. 최근 5년 결빙사고 발생이력이 있는 도로구간(Link)을 확인하고 Random Forest 알고리즘을 통해 도로 특성정보의 결빙사고에 대한 변수 중요도(Feature Importance)를 분석했다. 이를 통해 결빙사고와 각 인자의 상관성을 파악하여 ‘결빙 취약구간 평가 세부 배점표’의 항목별 배점을 수정, 보완함으로써 평가표의 신뢰성을 제고한다.

The Occupational Safety and Health Act (OSHA) aims to maintain and promote the safety and health of workers. Additionally, violations of the act can result in imprisonment or fines, depending on the severity of the offense. This study examines whether the severity of OSHA violations is proportional to the size of the fines imposed. There are 120 items subject to fines, with penalties ranging from a minimum of 50,000 won to a maximum of 30 million won. To assess the severity of these items, pairwise comparisons were conducted, and the results were expressed numerically. In summary, no significant correlation was found between the severity of violations and the amount of the fines. Therefore, this study proposes calculating fines based on the severity of violations. In many small companies, resources (e.g., budget and manpower) are limited. Thus, greater attentions tend to be directed toward addressing items with higher fines. Consequently, aligning the severity of legal violations with the size of the fines may contribute to improving the industrial safety.

This study analyzed the correlation between carcass traits of Hanwoo steers and feeding methods (concentrate feed and total mixed ration for ruminants). The results indicated that in the feeding system using concentrate feed, the variation in carcass weight and marbling score among individual animals within farms tended to affect the average carcass sale price, with both showing negative effects (p=0.057, p=0.053). The standardized regression coefficients were used to compare the influence of each variable, revealing that the coefficients for carcass weight variation and marbling score variation were –0.38 and –0.30, respectively, indicating a greater influence of carcass weight variation. Therefore, reducing the variations in carcass weight and marbling score among steers in farms using concentrate feed is likely to increase the average carcass sale price. In the case of farms using total mixed ration (TMR) for ruminants, the variation in marbling score among individual animals significantly affected the average carcass sale price, showing a negative effect (p=0.002). Thus, reducing the variation in marbling score among steers in TMR farms is likely to increase the average carcass sale price. In summary, the coefficient of variation of marbling score was found to have a significant impact on the average carcass sale price of the farm. In farms using concentrate feed, the variations in both carcass weight and marbling score tended to affect the average carcass sale price (0.05<p<0.1). Meanwhile, in farms using TMR, the variation in marbling score had a significant impact. In conclusion, the coefficient of variation for marbling score in carcass performance was found to have the most significant impact on the average carcass sale price for both feeding types (concentrate and TMR diets). Furthermore, reducing the variation along with carcass weight of Hanwoo steers on concentrate feed may be a way to increase farm income.

Piloti-type structures with vertical irregularity are vulnerable to earthquakes due to the soft structure of the first story. Structural characteristics of buildings can significantly affect the seismic loss function, calculated based on seismic fragility, and therefore need to be considered. This study investigated the effects of the number of stories and core locations on the seismic loss function of piloti-type buildings in Korea. Twelve analytical models were developed considering two variations: three stories (4-story, 5-story, and 6-story) and four core locations (center core, x-eccentric core, y-eccentric core, and xy-eccentric core). The interstory drift ratio and peak floor acceleration were assessed through incremental dynamic analysis using 44 earthquake records, and seismic fragility was derived. Seismic loss functions were calculated and compared using the derived seismic fragility and repair cost ratio of each component. The results indicate that the seismic loss function increases with more stories and when the core is eccentrically located in the piloti-type structure model. Therefore, the uncertainty due to the number of stories and core location should be considered when deriving the seismic loss function of piloti-type structures.

This paper introduces a study on measuring the 3D vibration displacement of plate structure using Digital Image Correlation (DIC) applied to stereo digital continuous camera images. The proposed method is a non-contact 3D displacement measurement method that does not require physical sensors to be attached to the structure, and it has the advantage of simultaneously measuring dynamic displacements at multiple points on the structure. Theoretically, multiple cameras can be used, but in this study, two cameras were used to capture continuous images of the vibrating structure, and the image coordinates of multiple tracking points at arbitrary positions on the structure were measured using correlation matching. Using these image coordinates as input data, the dynamic 3D positions were calculated through Space intersection, successfully determining the 3D dynamic displacements. The measured dynamic displacements were validated for accuracy by comparing them with values measured by laser displacement sensors. And frequencies of measured data were validated by comparing with computational modal analysis by Finite Element Model (FEM).

algorithms for deriving and analyzing retroreflectivity influence factors through regression analysis. METHODS : An experimental road lane was created to examine the trends of retroreflectivity and LiDAR intensity values, and a controlled indoor experiment was conducted to identify influencing factors. The optimal algorithm was developed by regression analysis of the experimental data. RESULTS : The significance probability (P-value) through SPSS linear regression analysis was 0.000 for measured height, 0.001 for perpendicular angle, 0.157 for vertical angle, and 0.000 for LiDAR intensity, indicating that measured height, vertical angle, and LiDAR intensity are significant factors because the significance probability is less than 0.05, and vertical angle is not significant. The NNR regression model performed the best, so the measurement data with height (1.2m, 2m, 2.2m) and vertical angle (11.3°, 12.3°, 13.5°) were analyzed to derive the optimal LiDAR Intensity measurement height and vertical angle. CONCLUSIONS : For each LiDAR measurement height and vertical angle, the highest correlation between LiDAR Intensity and retroreflectivity was found at a measurement height of 1.2 meters and a vertical angle of 12.3°, where the model learning accuracy (R2) was the highest.

This study aims to investigate the correlation between the causes of natural disasters and feng shui factors targeting disaster management experts, feng shui experts, and the general public who are interested in feng shui. To this end, it is intended to reveal that the factors of the disaster at Mt. The purpose of this study is to analyze the impact of three factors on disasters: feng shui factors, natural factors, and social factors. To this end, a survey was conducted targeting feng shui experts, disaster management experts, master's and doctoral students in feng shui geography, residents of the Umyeonsan disaster area, and people interested in feng shui geography. 260 copies of the questionnaire were prepared and 248 copies were used for the final analysis. First, in order to analyze the impact of feng shui factors on awareness of disaster occurrence, after controlling for demographic variables, hierarchical multiple regression analysis was conducted to analyze the impact of feng shui factors on awareness of disaster occurrence. Second, as a result of analyzing the effect of natural factors on awareness of disaster occurrence, looking at each independent variable in the second-stage regression analysis. Third, as a result of analyzing the effect of social factors on awareness of disaster occurrence, looking at each independent variable in the second-stage regression analysis. Finally, as a result of the T-test and Anova analysis conducted for discriminant analysis, if the p-value was less than .005, the F value for each group was obtained as a result of the ANOVA analysis on the feng-shui factors