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.

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.

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.

Phosphate coating is applied to the surface of the round bar material used in the multi-stage cold forging process for the purpose of lubrication. The film characteristics are determined according to the conditions of the phosphate film treatment process. In this study, the film properties according to the phosphate treatment conditions were defined as the coefficient of repeated friction and quantitative analysis was performed. Different friction behaviors were exhibited depending on the film properties, suggesting that optimization of the phosphate film treatment conditions is possible based on this. Finally, as a practical example, friction behavior according to the film characteristics was applied to the automotive engine bolt forming process. As a final conclusion, the need for linkage analysis with phosphating conditions for optimizing the forging process was raised. In addition, it can be seen that damage to the phosphate film should be considered in the process of predicting the limiting life of the die.

PURPOSES : In a previous study, an error was detected in data pertaining to the direction and velocity of a roller. Hence, in this study, the correlation between these two variables and acceleration data is analyzed. Relevant algorithms are developed by adding variables to existing algorithms. METHODS : A tachometer and GPS are used to acquire the velocity, compaction direction of rollers, and number of compactions. Subsequently, data input to an accelerometer are compared and analyzed. RESULTS : Based on FFT analysis, it is discovered that the data are inaccurate when a forward reverse is performed. Using the GPS, the velocity of the roller is differentiated based on the number of pledges, and then added as a variable to the algorithm. Subsequently, it is evaluated and analyzed only with data during forward movement based on changes in the latitude and longitude. CONCLUSIONS : It is discovered that the acceleration data values from both the left and right rollers differ owing to their weight difference, as indicated by the asphalt gradient. Data changes based on asphalt gradients are analyzed using gyro sensors. If the correlation between the two sets of data is high, then the algorithm is advanced by introducing a cross spectrum after calibrating the acceleration value based on the gradient.

목적: 안경사 직무를 분석하여 국가시험 교과목과의 연계성을 확인하고 대학의 시험과목 비율과 교육과정 개발에 기초자료를 제공한다. 방법 : 안경사 872명과 안경광학과 교수 99명을 대상으로 5개의 직무영역과 18개의 일로 구성된 설문을 조사하여 분석하였다. 결과 : 안경사 직무분석에서 작업의 중요도와 필요도가 모두 높은 영역에서 필요능력인 지식과 기술을 도출하여 안경조제가공(39.1%), 시력검사(27.5%) 및 콘택트렌즈(14.8%), 기타(18.6%)의 비중을 통해 안경사 1차 직무 분석(2000년)과 비교해 검안안경사 분야로 안경사의 직무가 이동된 것으로 나타났다. 결론: 안경사 직무에서의 변화는 안경사 국가시험과 대학의 교육과정에 적절히 반영되어야 할 것으로 생각된다.

Seismic fragility analysis of a structure is generally performed for the expected critical component of a structure. The seismic fragility analysis assumes that all the components behave independently in a structural system. A bridge system consists of many inter-connected components. Thus, for an accurate evaluation of the seismic fragility of a bridge, the seismic fragility analysis requires the composition of probabilities considering the correlation between structural components. This study presented a procedure to obtain the seismic fragility curve of a bridge system, considering the correlation between bridge components. Seismic fragility analysis was performed on a PSC bridge that is considered as the central infrastructure. The analysis results showed that the probability of the seismic fragility curve of the bridge system was higher than that of each bridge component.

This study was conducted to help manage total floating bacteria and fungi in the indoor air by studying the characteristics of total floating bacteria and fungi according to the indoor CO2 concentration of daycare centers. The sampling and analysis of samples was based on the indoor air quality process test method, and the result analysis was conducted using the SPSS statistical program to perform correlation and regression analysis. Correlation and regression results show that CO2 and total airborne bacteria showed positive relationships, but airborne mold did not show relevance. In addition, in order to identify factors affecting airborne mold, correlation analysis and regression analysis were performed regarding total airborne bacteria, PM10, PM2.5, HCHO, outdoor mold, I/O ratio, indoor temperature/ humidity, area per classroom and volume. The results showed that the factors affecting airborne mold were I/O ratio, outdoor airborne mold, and total airborne bacteria. Research results show that CO2 and total airborne bacteria can be reduced and controlled by natural ventilation, and in the case of airborne mold, mechanical forced ventilation such as hoods will be necessary due to the introduction of outdoor airborne mold. In addition, it is necessary to consider I/O ratio criteria in order to confirm effective indoor mold contamination, taking into account the effect of outdoor mold inflow.