This study explores the introduction and applicability of the Species Protection Index (SPI) as a tool to evaluate the effectiveness of biodiversity conservation. Specifically, the SPI was recalculated for amphibians in Korea and compared with the internationally provided SPI results. The pilot evaluation of SPI for amphibians showed an increase from 41.52, based on international data, to 44.25, indicating that SPI calculations using domestic data can reflect conservation status more accurately than international SPI results. The findings suggest that SPI can serve as an important scientific basis for formulating national biodiversity conservation policies and managing protected areas, contributing to the development of more effective conservation strategies.

This study points out the traffic safety inhibition problem in which the yellow time length at a signal intersection can be set differently depending on the tram, and proposes a way to overcome it. This study proposes a twofold approach for trams to coordinate with the yellow signal phase designated for general vehicles, utilizing a schedule-speed-based operating speed adjustment and departure time control at stations. To validate the proposed method, simulations were conducted for a planned tram corridor in the Wirye District, Seoul. The simulation environment was developed using the simulation of the urban mobility model. The operational characteristics of tram services in the main and branch-line sections were analyzed. In the upstream section of the mainline, the operating speed was 22.04 km/h, with a total dwell time of 400 s across 10 stations, resulting in zero intersection stops. Regarding the downstream section, the operating speed was 17.71 km/h, and one intersection stop was observed. In contrast, for the upstream section of the branch line, the operating speed was 14.73 km/h and there were two intersection stops, while the downstream section yielded an operating speed of 18.12 km/h, and also comprised two intersection stops. This study examined a novel operational strategy for trams near intersections along tram corridors without directly modifying the signal system. This strategy effectively utilizes tram stop dwell time and traffic signal information. It focuses on adjusting tram speeds to ensure smooth and safe passage through signalized intersections and optimizing operations so that trams approach and cross intersections at a consistent speed. Designed as a universal model, this strategy is adaptable to various regions and environments, rather than being limited to a specific area. It is expected to support tram operation planning by considering diverse factors, such as urban structure, traffic density, and intersection characteristics. Moreover, it provides valuable guidance to ensure the punctuality and stability of tram operations in a range of urban and traffic contexts.

This study is about the evaluation for shock-proof performance of the system, elastically support the low accumulator of the naval artillery against underwater explosion, using DDAM. For the evaluation, the shock analysis procedure using DDAM, supported by MSC/NASTRAN, was briefly described. In addition, in order to perform the shock analysis, the elastic support system was modeled as a finite element. The shock analysis of the elastic support system was performed by selecting the analysis frequency range so that reliable results can be obtained. Finally, the shock-proof performance of the system was evaluated by comparing the shock analysis results with the properties of the elastic support system.

PURPOSES : This study was conducted to prevent slip accidents on manhole covers located on sidewalks and local roads as well as to propose reasonable slip resistance management standards for manhole covers. METHODS : Using field surveys, test groups were classified based on the patterns and wear amounts of the manhole covers. Standards for measuring the equipment and methods for slip resistance were established, and the slip resistance values were compared and analyzed for each manhole cover test group. RESULTS : According to the slip resistance test results, micro-protrusions on the non-slip manhole covers were found to be effective in improving slip resistance. However, in areas without microprotrusions, the improvement in slip resistance was minimal and yielded results similar to those of standard manhole covers. In addition, among the pattern types of standard manhole covers, the radial pattern was found to be the most susceptible to slipping. Under the current wear measurement standards, the change in slip resistance at different wear stages was found to be relatively small. Moreover, manhole covers had the lowest slip resistance among road surface structures, indicating the need to establish management standards for them. CONCLUSIONS : To prevent pedestrian slip accidents on sidewalks and local roads, it is necessary to ensure that the slip resistance standards of manhole covers are higher than those of sidewalks.

현재 국내에서는 아스팔트 포장의 예방적 유지보수공법의 사용이 미미하며, 시공 기준 또한 부재한 실정이다. 이에 따라 포장가속시 험시설을 활용하여 예방적 유지보수공법 적용에 대한 공용성 변화 분석을 진행하였다. 본 연구에서는 포그씰 A, B 공법에 대해 도포 량을 다르게 시공하여 기능성 인자인 BPN, MPD와 물성 인자인 공극률에 대해 추적조사를 진행하여 공용성 변화를 분석하였다. 주행 횟수의 산정은 가속시험기의 등가단축하중(ESAL, Equivalent SIngle Axle Load)의 관계식을 통해 실제 교통량을 등가단축하중으로 환산 하여 가속시험 주행 횟수를 산정하여 시공 후 공용 1년까지의 성능을 분석하였다. 분석 결과 기능성 인자인 MPD는 차량 주행으로 인 해 점차 감소하였으며, BPN은 시공 직후 포그씰 처리로 인한 미끄럼 저하가 지배적으로 나타났으나 점차 회복되는 것으로 나타났다. 물성 인자인 공극률은 주행 횟수가 증가할수록 포그씰이 포장 표면으로 채워져 공극률이 줄어드는 것으로 나타났다. 도포량별 분석 결과 도포량이 가장 많은 구간에서 저하율이 모든 인자에서 가장 큰 것으로 나타났으며, 두 도포량의 경우 인자별로 미세한 차이는 존재하였으나 대부분 비슷한 경향을 보이는 것으로 확인되었다.

국내 도로 연장은 2023년 기준 115,878km로 매년 증가하는 추세를 보이고 있다. 이중 준공 30년 이상된 노후도로의 비율은 51.5%에 해당하고 있어 도로 유지관리의 중요성이 대두되는 실정이다. 본 연구에서는 아스팔트 예방적 유지보수공법인 포그씰(Fog Seal)을 실 제 공용중에 있는 도로에 적용하여 공용성 변화를 분석하였다. 공용성능 분석을 위해 차량의 휠패스 부분에서 공법당 6개의 코어를 3 차년간 채취하여 공극률 및 바인더 함량 값을 비교하였다. 분석 방법으로는 포그씰 공법을 시공하지 않은 구간을 대조군으로 선정하 여 추적조사 기간에 따른 변화 추이를 분석하였다. 분석 결과, 공극률은 포그씰 시공 이후 지속적인 감소를 보였다. 바인더 함량의 경 우 공용연수가 증가할수록 바인더 함량 또한 점차 증가하는 것으로 확인되었다. 이는 공용연수가 증가함에 따라 차량의 주행으로 인 해 표면에 도포된 포그씰이 점차 도로 표면 및 균열 속으로 스며들어 내부의 공극이 채워지는 것으로 판단된다.

현재, 교통안전진단의 경우 차량 및 보행자의 교통사고를 미연에 방지하고 도로의 전체적인 안전을 도모하고자, 교통안전법 제34조 에 의거하여, 수행 조건에 부합한 경우 교통안전진단을 받도록 규정하고 있다. 교통안전진단의 경우 도로의 구분에 따라 다른 기준을 적용하고 있으며, 도로별 길이를 기준으로 수행 여부를 판단하고 있다. 교통안전진단의 경우 도로의 설계단계, 개시 전 단계 및 운영단계 등 3가지로 구분되어 수행되고 있으며, 각각의 단계별로 진단 수행 내용 및 범위가 조금씩 다르게 진행된다. 설계 단계에서의 교통안전진단의 경우, 해당 도로의 실시 설계 내용을 바탕으로 도로의 안전 을 판단하며, 개시 전 단계의 경우 도로의 신설 이후 운영 전 도로의 안전을 평가한다. 마지막으로 운영 단계의 교통안전진단의 경우 현재 운영 중인 도로에 대하여 도로의 안전을 평가하는 것이다. 본 연구에서는 진단단계별 교통안전진단 중 도로 설계단게에서 수행 시 발생될 수 있는 한계점을 파악하고, 이를 보완할 수 있는 방 안을 제시하여 그 효과를 분석하고자 한다. 또한, 국제 기준으로 운영되고 있는 iRAP(International Road Assessment Programme)의 SR4D( Star Rating for Design)을 통해 설계단계의 교통안전진단 수행 시 효과적이고 안전한 진단결과를 도출해내고자 한다.

This paper evaluates the use of Factor Analysis (FA) in English education research in Korea and suggests improvements in methodology. A detailed coding protocol was used to review 179 FA cases from 12 major English education journals (2014-2023). The review identified several key issues, including small sample sizes and lenient criteria for sample size selection, insufficient reporting on data appropriateness and normality, confusion between principal component analysis and FA, overreliance on the Eigenvalue > 1 criterion for determining the number of factors, inappropriate factor rotation methods, inconsistency between factor rotation and extraction methods, inadequate reporting on factor loadings and cross loadings criteria, and excessive reliance on SPSS as a statistical tool for FA. This study provides specific guidelines for applying FA appropriately and reporting results accurately.

The purpose of this study is to present a plan for reducing noise between floors of apartment houses in Korea and to examine the method for evaluating noise blocking performance rating between floors. The definition of floor noise and classification method of floor noise can be described, and floor noise can be distinguished into lightweight impact sound and heavy impact sound. The wall-type structure, which is mainly adopted in domestic apartments, relatively transmits vibration caused by impact sources rather than using columns and beams, so noise problems between floors are relatively higher than systems using columns and beams. Three representative methods for reducing and blocking floor noise are described, and criteria for evaluating the effectiveness of floor noise reduction by each method are described. In addition, the method for noise reduction and blocking grades for each construction method currently applied in Korea was described, and as a result, it was judged that the domestic rating evaluation method was not suitable for the current domestic situation, and a new evaluation method and standard were needed.

식품공전 시험법은 식품기초규격 적부 판정, 수거검사의 적부판정, 수입식품의 적부판정 등의 판단근거가 되기 때문 에 식품산업에서 매우 중요하다. 본 연구는 도시락, 밀키트, 된장에 오염된 일반세균, 대장균군, 효모, 곰팡이, 대장균을 분리하기 방법으로 사용되는 평판배지법, Petrifilm법, Compact Dry법을 이용해 각각의 세균을 분리하였고, 회수율을 비교 하였다. 식품 내 자연균총(일반세균, 효모/곰팡이, 대장균군) 검출은 평판배지 PCA, PDA, DCLA와 Petrifilm AC, YM, CC의 성능을 Compact Dry TC, YMR, CF와 비교하였다. 인 위접종한 대장균(E. coli)의 경우는 평판배지 EMB, Petrilfilm EC, Compact Dry EC의 검출능을 비교하였다. 본 실험결과, 일반세균, 대장균군, 대장균의 검출에서 Compact Dry법은 기 존의 평판배지법 및 건조배지법과 비교하여 식품 내 각각의 세균수를 계수하는데 유의적 차이를 보이지 않았다(P>0.05). 또한, 평판배지법과 Compact Dry간의 상관관계 및 Petrifilm 과 Compact Dry간의 상관관계 역시 1에 가까운 높은 값을 확인하였다. Compact Dry법은 미생물 분석을 위해 배지 준 비 과정이 필요 없으며, 접종 후 자체 확산이 가능하여 사 용하기 쉽고, 공간을 효율적으로 사용할 수 있으므로 기존 의 배지를 사용하는 방법에 비해 많은 장점을 제공하였다. 따라서 식품 중 일반세균, 대장균군, 대장균의 검출을 위한 Compact Dry법(Compact Dry TC, CF, EC)은 기존의 식품공 전 상 등재된 다른 건조필름법을 대체 가능한 것으로 판단된다.

선박 건조 과정에서 블록이나 장비를 지지하는 A형 캐리어 구조는 하중 변경과 시간이 지남에 따라 점차 변형이 증가하며, 이 에 따라 블록과 접촉하는 면적이 감소하고 분산된 하중에서 집중된 하중으로 패턴이 변화한다. 이러한 현상은 실제 사용 하중을 오판할 가능성이 있다. 특히 A형 캐리어는 영세한 제조 업체에서 자주 사용하고 있으며, 별도의 엔지니어링 기능이 없는 상황이 대부분이라서 손 쉽게 캐리어의 안전사용하중을 계산하는 방법의 개발이 필요하다. 본 연구는 A형 캐리어가 장기적으로 안전하게 사용할 수 있는 하중을 신속하게 평가하는 방법을 제안함으로써, 하중 분포의 변화에 따른 소성 변형과 그로 인한 안전 문제를 예측하고 대응할 수 있다. 제안된 방법은 캐리어의 중앙 집중하중과 전체 분포하중 조건에 대해서 유한요소해석(빔, 쉘 모델링)을 통한 결과를 기반으로 빔-이론을 수정하 여 제안되었다. 빔 모델링에서 집중하중 조건은 보정계수 0.73, 분포하중에서는 0.69를 이론값에 곱해서 안전사용하중이 가능하다. 쉘 모 델링의 경우, 집중하중은 0.75와 분포하중은 0.69를 사용할 수 있다. 본 연구는 선박 건조 작업 현장의 안전을 개선하고, 실제 작업 환경에 서의 안전 사용 하중 판단에 신속하고 효과적인 결정을 내릴 수 있는 기초 자료로 활용될 수 있다.

PURPOSES : This study aims to provide quantitative profile values for the objective evaluation of concrete surface profile (CSP) grades in concrete structures. The main aims are to quantify the CSP grade required for concrete surface pretreatment and proposing a more suitable CSP grade for structural maintenance. METHODS : Initially, the challenges in measuring concrete surface profiles were outlined by analyzing pretreatment work and profile samples of concrete pavements. Theoretical foundations for quantifying concrete surface roughness were established, and regression models including linear regression, cubic regression, and log regression were selected. Additionally, the interquartile range anomaly removal technique was employed to preprocess the data for regression modeling. RESULTS : Concrete CSP profiles were measured through indoor tests, and the measured data were quantified. Linear regression, cubic regression, and log regression models were applied to each CSP grade for comparative analysis of the results. Furthermore, comparative studies were conducted through adhesion strength tests based on the CSP grade. CONCLUSIONS : Our results are expected to establish objective standards for the pretreatment stage of concrete repair and reinforcement. The derived reference values can inform standards for the restoration and reinforcement of concrete structures, thereby contributing to performance improvement. Moreover, our results may serve as primary data for the repair and reinforcement of various concrete structures such as airports, bridges, highways, and buildings.

PURPOSES : Recently, air pollution due to fine particulate matter has been increasing in Korea. Nitrogen oxides (NOx) are particulate matter precursors significantly contributing to air pollution. Increasing efforts have been dedicated to NOx removal from air, since it is particularly harmful. Application of titanium dioxide (TiO2) for concrete road structures is a suitable alternative to remove NOx. As the photocatalytic reaction of TiO2 is the mechanism that eliminates NOx, the ultraviolet rays in sunlight and TiO2 in existing concrete structures need to be contacted for the reaction process. For the application of vertical concrete road structures such as retaining walls, side ditches, and barriers, a pressurized TiO2 fixation method has been developed considering the pressure and pressurization time. In this study, longterm serviceability and repeatability were investigated on concrete specimens applying the dynamic pressurized TiO2 fixation method. Additionally, the environmental hazards of nitrate adsorbed on TiO2 particles were evaluated. METHODS : Concrete specimens to simulate roadside vertical concrete structures were manufactured and used to evaluate the long-term serviceability and repeatability of the dynamic pressurized TiO2 fixation method. The NOx removal efficiency was measured using NOx evaluation equipment based on ISO 22197-1. In addition, the nitrate concentration was measured using a comprehensive water quality analyzer for evaluating environmental hazards. RESULTS : As the experiment to evaluate the NOx removal efficiency of the dynamic pressurized TiO2 fixation method progressed from one to seven cycles, the nitrate concentration increased from 2.35 mg/L to 3.06 mg/L, and the NOx removal efficiency decreased from 53% to 25%. After seven cycles of NOx removal efficiency evaluation, the average nitrate concentration was 3.06 mg/L. The nitrate concentration collected immediately after the NOx removal efficiency test for each cycle was in the range of 2.51 to 2.57 mg/L. By contrast, it was confirmed that the nitrate concentration was lowered to approximately 2.1 mg/L when the surface was washed with water. CONCLUSIONS : The NOx removal efficiency was maintained at over 25% even after seven cycles of NOx removal efficiency evaluation, securing long-term serviceability. In addition, the harmful effects on the environment and human health are insignificant, since the nitrate concentration was less than 10 mg/L, in accordance with domestic and foreign standards. Practical applicability of the pressurized TiO2 fixation method was established by evaluating the long-term serviceability, repeatability, and environmental hazards.

Water utilities are making various efforts to reduce water losses from water networks, and an essential part of them is to recognize the moment when a pipe burst occurs during operation quickly. Several physics-based methods and data-driven analysis are applied using real-time flow and pressure data measured through a SCADA system or smart meters, and methodologies based on machining learning are currently widely studied. Water utilities should apply various approaches together to increase pipe burst detection. The most intuitive and explainable water balance method and its procedure were presented in this study, and the applicability and detection performance were evaluated by applying this approach to water supply pipelines. Based on these results, water utilities can establish a mass balance-based pipe burst detection system, give a guideline for installing new flow meters, and set the detection parameters with expected performance. The performance of the water balance analysis method is affected by the water network operation conditions, the characteristics of the installed flow meter, and event data, so there is a limit to the general use of the results in all sites. Therefore, water utilities should accumulate experience by applying the water balance method in more fields.

Particulate matter is known to have adverse effects on health, making it crucial to accurately gauge its concentration levels. While the recent advent of low-cost air sensors has enabled real-time measurement of particulate matter, discrepancies in concentrations can arise depending on the sensor used, the measuring environment, and the manufacturer. In light of this, we aimed to propose a method to calibrate measurements between low-cost air sensor devices. In our study, we introduced decision tree techniques, commonly used in machine learning for classification and regression problems, to categorize particulate matter concentration intervals. For each interval, both univariate and multivariate multiple linear regression analyses were conducted to derive calibration equations. The concentrations of PM10 and PM2.5 measured indoors and outdoors with two types of LCS equipment and the GRIMM 11-A device were compared and analyzed, confirming the necessity for distinguishing between indoor and outdoor spaces and categorizing concentration intervals. Furthermore, the decision tree calibration method showed greater accuracy than traditional methods. On the other hand, during univariate regression analysis, the proportion exceeding a PM2.5/PM10 ratio of 1 was significantly high. However, using multivariate regression analysis, the exceedance rate decreased to 79.1% for IAQ-C7 and 89.3% for PMM-130, demonstrating that calibration through multivariate regression analysis considering both PM10 and PM2.5 is more effective. The results of this study are expected to contribute to the accurate calibration of particulate matter measurements and have showcased the potential for scientifically and rationally calibrating data using machine learning.