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

이 연구는 1세대 스마트 온실의 재배환경 데이터와 장미 절 화의 품질 특성 데이터를 수집하고 그 요인들 간의 상관 관계 를 분석하여 절화수명 예측 및 최적 환경 조성의 기초 자료를 얻고자 수행되었다. 이를 위해, 토경재배(SC) 및 암면배지경 양액재배(RWH) 하우스 각 1개소를 선정하여 1년간 기온, 상 대습도(RH) 및 수증기압차(VPD), 일적산광량(DLI), 근권온도 등의 환경 데이터와 매월 말 수확된 장미 ‘Miss Holland’ 절 화의 품질 특성 데이터를 수집하였으며, 이 데이터와 절화수 명과의 상관관계를 분석하였다. 절화수명은 10월과 11월을 제외하고는 SC 하우스에서 RWH 하우스보다 더 길었다. 절 화수명과 환경 및 생육 특성 간의 상관관계 분석에서 SC 하우 스의 상관계수는 RWH 하우스보다 조금 더 높았으며, 절화수 명 예측을 위한 요소들도 두 하우스 간에 차이가 있었다. SC 하우스의 절화수명 Y=0.848X1+0.366X2-0.591X3+2.224X4- 0.171X5+0.47X6+0.321X7+9.836X8-110.219(X1-X8: 최고 RH, RH 일교차, DLI, pH, Hunter’s b value, EC, 절화 장, 잎 두께; R2=0.544)로 예측되었고, RWH 하우스의 절화수명 Y=-1.291X1+52.026X2-0.094X3+0.448X4-3.84X5+0.624X6 - 8.528X7+28.45(X1-X7: 경경, 야간 VPD, 최고 근권온도, 최 저 근권온도, 기온 일교차, RH 일교차, 최고 VPD; R2=0.5243) 로 예측되었다. 이 두 모델식으로부터 SC 하우스에서는 RH, EC 및 pH가, 그리고 RWH 하우스에서는 근권 온도가 절화수명에 더 큰 영향을 미친다는 것을 추론할 수 있다. 따라서 각 재배 방법에 따라 장미의 절화수명에 더 큰 영향을 미치는 환경적 요인을 효율적으로 관리할 필요가 있다.

본 연구는 단기소득임산물 중 산림임업통계자료에 의한 생산량과 수요가 증가하고 있는 추세인 약용수 (꾸지뽕나무, 마가목, 헛개나무) 자생지를 대상으로 식물사회학적 방법에 의해 군락을 구분하여 식생 구조를 파악하고 Ordination CCA에 의한 군락구조와 환경요인의 상관관계를 분석하여 산채류 재배지 환경조성에 필요한 생태학적 기초자료를 제공하기 위하여 2021∼ 2022년에 수행되었다. 우리나라 꾸지뽕나무 자생지는 주로 남부지역에 분포하고 5개 지역, 11개 조사구를 대상으로 조사하였고, 마가목 자생지는 주로 고산지역에 분포하고 3개 지역, 8개 조사구를 대상으로 조사하였으며, 헛개나무 자생지는 중부 계곡부에 분포하고 5개 지역, 17개 조사구를 대상으로 조사하였다. 각 분류군의 중요치를 살펴보면, 꾸지뽕나무군락에서 나타난 중요치는 꾸지뽕나무가 61.10으로 가장 높았고 다음으로 팽나무, 곰솔, 새덕이, 때죽나무, 소사나무, 졸참나무, 상수리나무 등의 순으로 나타났고, 마가목군락에서는 신갈나무가 57.21로 가장 높았고 다음으로 마가목 42.58, 사스래나무, 피나무, 당단풍나무, 시닥나무, 층층나무, 함박꽃나무, 주목 등의 순으로 나타났으며, 헛개나무군락에서는 헛개나무가 64.58로 가장 높았고 다음으로 느티나무, 층층나무, 고로쇠나무, 졸참나무, 까치박달, 가래나무 등의 순으로 나타났다. 중요치가 높은 주요 분류군에 대한 흉고직경급을 분석한 결과 꾸지뽕나무군락에서는 꾸지뽕나무, 팽나무, 새덕이 및 소사나무는 어린 개체의 밀도를 높게 나타내고 있어 당분간은 이들 수종의 우점 상태가 계속 증가 될 것으로 보인다. 마가목군락에서 마가목은 역 J자형을 하고 있어 우점 상태가 계속 증가할 것으로 보이며, 신갈나무, 사스래나무 및 피나무는 정규분포형의 밀도를 나타내고 있어 당분간은 이들 수종의 우점 상태가 계속될 것으로 판단된다. 헛개나무군락에서는 까치박달과 가래나무는 역 J자형을 하고 있어 우점 상태가 계속 증가할 것으로 보이며, 헛개나무, 느티나무, 층층나무 및 고로쇠나무는 각 층에서 전체적으로 개체의 밀도가 높아 계속적으로 높은 우점도를 유지할 것으로 예상된다. TWINSPAN에 의해 분류된 3분류군의 30개 군락과 11개의 환경 요인으로 CCA ordination 결과, 해발고가 가장 높은 상관관계를 보였고, 꾸지뽕나무군락은 pH, C.E.C, Ca2+ 및 Mg2+ 는 가장 높고, 해발고는 낮고 남동사면과 남서사면의 경사는 완만하였으며, P2O5는 높은 지역과 낮은 지역에 골고루 분포하였다. 마가목군락은 해발고는 높고, 북사면의 경사는 다소 급하고, O.M과 T-N은 가장 많으나, 그 외 양료들은 적으며, pH는 낮게 나타났다. 헛개나무군락은 북동사면과 북서사면에서 해발고와 경사는 중간 지역이고, P2O5는 높게 나타났다.

중국어에서는 형태변화를 나타내는 표지의 결핍으로 두 개 이상의 품사성을 지닌 많은 ‘겸류사’가 많다. 사실 ‘겸류사’의 탄생은 구문에서 품사의 다기능이 지닌 경계 의 설정에 있었지만, 오히려 ‘양사가 형용사를 수식’하거나 ‘부사가 명사를 수식’하는 비정상적 어법구조를 형성하였다. 본문은 어법화의 각도에서 개사와 조사의 어법화 과정을 ‘기능전환’과 ‘품사전성’이라는 두 가지 각도에서 대비하여 살펴보았고, 본래 품사가 지닌 전형적 ‘범주속성’의 ‘임시전환(游移)’현상에 근거하여 ‘기능전환’에 따른 ‘활용’이라는 방식으로 접근해 보았다. 아울러 “양사가 형용사를 수식한다”는 주장에 대해 기존 ‘명물화(名物化)’ 관점에서 정도성 양범주의 공간화 관점에서 고찰하였으 며, 또 “부사가 명사를 수식한다”는 공간 양범주의 ‘형질화(形質化)’라는 측면에서 양 범주의 정도성을 통해 명사의 윤곽을 해체하는 방식으로 접근해 보았다.

To understand functional changes of forest ecosystems due to climate change, correlation between decomposition rate of leaf litter, an important function of forest ecosystems, and microclimatic factors was analyzed. After 48 months elapsed, percent remaining weight of Quercus mongolica leaf litter was 27.1% in the east aspect and 37.0% in the west aspects. Decay constant of Q. mongolica leaf litter was 0.33 in the east aspect and 0.25 in the west aspect after 48 months elapsed. Initial C/N ratio of Q. mongolica leaf litter was 38.5. After 48 months elapsed, C/N ratio of decomposing Q. mongolica leaf litter decreased to 13.43 in the east aspect and 16.72 in the west aspect. Average air temperature and soil temperature during the investigation period of the research site were 8.2±9.0 and 9.1±9.3 in the east and 8.5±7.4 and 9.3±7.3°C in the west aspect, respectively, with the west aspect showing higher air and soil temperatures. Soil moisture showed no significant difference between east and west aspects (average soil moisture: 19.4±11.0% vs. 20.5±5.7%). However, as a result of analyzing the correlation between decomposition rate and microclimatic factors, it was found that the decomposition rate and soil moisture has a positive correlation (r=0.426) in the east aspect but not in the west aspect. Our study shows that the correlation between decomposition rate and microclimatic factors can be significantly different depending on the direction of the aspect.

Complaints about foul odors are emerging as an issue, and the number of complaints is steadily increasing every year. Biofiltration is known to remove harmful or odorous substances from the atmosphere by using microorganisms, and full-scale biofilters are being installed and operated in various environmental and industrial facilities. In this study, the current status and actual odor removal efficiency of full-scale biofilters installed in publicly owned treatment facilities such as sewage, manure, and livestock manure treatment plants were investigated. In addition, the effects of design and operating factors on their efficiency were also examined. As a result, it was found that odor prevention facilities with less than 30% odor removal efficiency based on complex odors accounted for 40%-50% of the biofilters investigated. In investigating the appropriate level of operating factors on odor removal efficiency, it was found that compliance with the recommended values p lays a significant role in improving odor removal efficiency. In the canonical correlation analysis for the on-site biofilter operation and design data, residence time and humidity were found to be the most critical factors. The on-site biofilter operation and design data were analyzed through canonical correlation analysis, and the residence time and humidity maintenance were found to be the most important factors in the design and operations of the biofilter. Based on these results, it is necessary to improve the odor removal efficiency of on-site biofilters by reviewing the effectiveness of the operation factors, improving devices, and adjusting operating methods.

To test a flameproof enclosure for the safety certificate, a reference pressure of explosion needs to be determined. However, the explosion pressure may be changed according to relative humidity of explosive gases. Therefore, the guideline on relative humidity should be recommended for measuring the explosion pressure for accurate and reproducible testings. This study examined the relationship of explosion pressure with relative humidity of hydrogen (31 vol %)-air and acetylene (14 vol %)-air mixture gases. The explosion pressures were measured by increasing the relative humidity of the gases by 10 % from dry state to 80 % in a cylindrical explosion enclosure of 2.3 L. on ambient temperature and atmospheric pressure (1 atm). The maximum explosive pressures were remained almost constant until the relative humidity reached 10 % for the hydrogen-air mixture and 20 % for the acetylene-air mixture. However, the maximum explosive pressures linearly decreased as the relative humidity increased. Based on the results of the study, it would be recommended to use 10 % relative humidity for the hydrogen-air mixture and 20 % for the acetylene-air mixture as the critical value in testing a flameproof enclosure.

PURPOSES : Local governments in Korea, including Incheon city, have introduced the pavement management system (PMS). However, the verification of the repair time and repair section of roads remains difficult owing to the non-existence of a systematic data acquisition system. Therefore, data refinement is performed using various techniques when analyzing statistical data in diverse fields. In this study, clustering is used to analyze PMS data, and correlation analysis is conducted between pavement performance and influencing factors. METHODS : First, the clustering type was selected. The representative clustering types include K-means, mean shift, and density-based spatial clustering of applications with noise (DBSCAN). In this study, data purification was performed using DBSCAN for clustering. Because of the difficulty in determining a threshold for high-dimensional data, multiple clustering, which is a type of DBSCAN, was applied, and the number of clustering was set up to two. Clustering for the surface distress (SD), rut depth (RD), and international roughness index (IRI) was performed twice using the number of frost days, the highest temperature, and the average temperature, respectively. RESULTS : The clustering result shows that the correlation between the SD and number of frost days improved significantly. The correlation between the maximum temperature factor and precipitation factor, which does not indicate multicollinearity, improved. Meanwhile, the correlation between the RD and highest temperature improved significantly. The correlation between the minimum temperature factor and precipitation factor, which does not exhibit multicollinearity, improved considerably. The correlation between the IRI and average temperature improved as well. The correlation between the low- and high-temperature precipitation factors, which does not indicate multicollinearity, improved. CONCLUSIONS : The result confirms the possibility of applying clustering to refine PMS data and that the correlation among the pavement performance factors improved. However, when applying clustering to PMS data refinement, the limitations must be identified and addressed. Furthermore, clustering may be applicable to the purification of PMS data using AI.

전 세계 각국은 탄소 배출량을 줄이기 위한 다양한 노력을 하고 있다. 지난 수십 년간 몇몇 연구자들은 탄소배출량 을 줄이기 위해서 철근콘크리트 구조에서 철근을 FRP로 대체하기 위한 연구를 수행해 왔다. FRP보강근을 휨부재로 사용하기 위한 연구는 많이 수행되어 왔으나, FRP 보강근 기둥의 성능을 평가하고 설계하기 위한 연구는 거의 이루어지지 않았다. 본 연 구는 FRP보강근 콘크리트 구조 기둥과 철근콘크리트 기둥의 P-M 상관도를 비교하고, 철근콘크리트 기둥에서 철근의 대체재로 서 FRP보강근의 활용 가능성을 제시하였고, 변수는 콘크리트의 압축강도, FRP보강근의 종류, 보강근비이다.철근을 GFRP로 대체 할 경우, 요구 GFRP 보강근의 양은 철근의 4배이며, 철근비가 4% 이상이면 동일한 단면으로는 설계할 수 없다. 편심거리비가 1.0보다 크거나 철근비가 4%보다 작은 철근콘크리트 기둥의 철근을 CFRP로 대체할 경우, 보강근의양을 1/2수준으로 줄이거나 단면 크기를 줄일 수 있다.