Current portable reference equipment used to evaluate the performance of vehicle detectors can collect traffic volume and speed only for the outermost lanes in each direction. Passing vehicles on the other lanes are manually counted by reviewing the recorded videos. Consequently, only traffic volume—without vehicle speed—is used as a reference value. This method is time-consuming for comparing the performance data from the equipment with the reference data and can compromise the performance evaluation. This study aims to enhance the efficiency of vehicle detection system (VDS) performance evaluations by developing multilane portable reference equipment that can accurately collect traffic information for lanes beyond the outermost lane or for more than two lanes. This study introduced the core technologies of multilane portable reference equipment and compared and analyzed the measurement accuracy of the developed equipment against data from fixed reference equipment operated by the Intelligent Transportation System (ITS) Certification and Performance Evaluation Center, following ITS performance evaluation criteria. The data from the fixed reference equipment were considered the true values, providing a basis for evaluating the accuracy of the measurements by the developed equipment. First, the accuracy of the vehicle length was determined by driving four test vehicles, each measuring 7,085 mm in length, 24–29 times in each lane. The accuracy was calculated by comparing the vehicle length data obtained from the fixed reference equipment with the actual vehicle length. A confidence interval was established for this accuracy. To assess the accuracy of the speed and occupancy time in relation to the accuracy of the analyzed vehicle length, we evaluated the error range of the vehicle length according to variations in speed and occupancy time. This analysis was based on the following relationship equation: “vehicle length = speed × occupied time – sensor spacing.” The analysis used data from approximately 16,000 vehicles, including the speed, occupancy time, and vehicle length, collected between 8:00 am and 12:00 pm on August 8, 2024. The principle behind measuring traffic volume and vehicle speed using multilane portable reference equipment involves detecting a vehicle by analyzing the time difference between the driver and passenger tires. The vehicle speed was calculated using the installation angle of the tire detection sensor and trigonometric functions. An analysis of the measurement accuracy revealed that the traffic volume accuracy of the outermost lane (the fourth lane) was 100% during both day and night. The speed accuracy was 98.8% during the day and 97.7% at night, representing the highest performance in these metrics. Additionally, the traffic volume accuracy for the innermost lane (the first lane), as measured by the detection sensor from the third lane, was more than 99.3% at all times, with a speed accuracy exceeding 96% during the day and night, that also demonstrated excellent results. The analysis results indicated that the multilane portable reference equipment developed in this study was suitable for evaluating the VDS performance. This equipment allowed the collection of traffic volume and speed data from all lanes, rather than only the outermost lanes. This capability enabled consistent analysis for each lane and enhanced efficiency by reducing the analysis time. Additionally, this is expected to improve the reliability of the performance evaluations.
Virtual Reality Head Mounted Display (VR HMD)-based flight simulators have recently emerged as promising tools for enhancing pilot training effectiveness. This study aims to establish a set of evaluation criteria for the development of VR HMD-based flight simulators and to determine their relative importance and priority using the Analytic Hierarchy Process (AHP). Through an extensive review of the literature, a hierarchical evaluation model was constructed, consisting of three primary criteria and ten sub-criteria. A structured questionnaire was administered to experienced pilots, and the collected data were analyzed using the AHP methodology to assess the relative weights of each criterion. The analysis revealed that the fidelity of system performance is the most influential factor in evaluating VR HMD-based flight simulators. These findings present a structured evaluation framework and offer practical insights for guiding the strategic development and optimization of VR HMD-based flight training systems.
Microreactors, a type of Small Modular Reactor (SMR) under 20 MWt, are being developed globally for use in remote areas, utilizing fourth-generation nuclear technology for enhanced safety. However, there are no established standards for their commercialization. This study reviews road transport regulations for microreactors and proposes necessary design loads and evaluation criteria for their transport. Transport concepts were identified through a review of overseas developments, with requirements derived for both accident and normal conditions. The study also presents an approach for evaluating transport stability based on land-based nuclear plant regulations, considering load conditions from drops and puncture impacts, as well as random vibrations during road transport. This work aims to support the design of mobile reactor transport systems and contribute to new regulatory and licensing procedures for advanced reactors.
This study reassessed two KBA sites in the Republic of Korea following the KBA guidelines. Both sites met the sub-criteria A1a, A1b, and D1a, confirming their status as KBA. These assessments provide a scientific foundation for discussions on designating new protected areas or expanding existing ones. Through this study, we confirmed that continuous biodiversity conservation is essential for Geum-gang river and estuary and Yubu-do to maintain their KBA status. This KBA reassessment provides an important scientific foundation for discussions on the designation of new protected areas or the expansion of existing ones. Furthermore, this study was based on a previously evaluated taxonomic group, birds, highlighting the need for future assessments to include other biological taxa and evaluation criteria, such as Criteria B or E, for a more comprehensive analysis.
본 연구의 목적은 사회복지 관련 학술지들을 대상으로 구조화된 논문심사기준들의 상대 적인 비중을 규명하는 데 있다. 이러한 연구목적을 달성하기 위해 24개 사회복지관련 학술 지들을 대상으로 내용분석을 실시하였다. 그 결과, 구조화된 논문심사기준들에 대한 총 이용 빈도수는 275회로 나타났다. 이 가운 데 독창성이 52회(18.9%), 정확성이 11회(4.0%), 객관성이 22회(8.0%), 일관성이 14회 (5.1%), 검증성이 61회(22.2%), 가독성이 39회(14.2%), 효용성이 75회(27.3%), 기타 논문심사기준이 1회(0.4%)인 것으로 판명되었다. 효용성, 검증성, 독창성, 가독성, 객관성, 일관성, 정확성, 기타 심사기준 순으로 상대적으로 높은 빈도수를 보이는 것으로 나타났다. 마지막으로 이 연구에서의 결과를 토대로 연구의 시사점과 추후 연구과제에 대해 간략하게 논의하였다.
선박 연료로서 LPG는 현재의 기술과 경제성 등을 고려하였을 때 매력적인 연료이다. 하지만, 아직 LPG 연료 선박의 안전 지침 을 개발 중에 있고, 국내에서는 중소형 선박에 LPG 추진 시스템을 적용한 사례가 없다. 본 연구에서는 국내 최초 개발된 해상용 LPG 엔 진 시스템에 대해 보다 객관적인 위험성 평가를 수행하고 안전 운용 기준을 제안하고자 한다. 우선, 위험과 운전 분석 기법을 통해 동 엔 진 시스템을 5개의 검토 구간으로 분할하고 총 58가지의 위험요소를 식별하였다. 그다음 정성적 평가인 HAZOP 기법의 주관성을 보완하 기 위해 퍼지 이론을 사용하고 검출도, 민감도 등 위험 요인을 추가하여 퍼지 분석적 계층 과정을 통해 위험 요인의 상대적 가중치를 비 교하였다. 그 결과, 5가지의 위험 요인 중, 위험성에 가장 큰 영향을 미치는 위험 요인은 발생 빈도와 심각도로 평가되었다. 마지막으로, 위험 요인에 대한 가중치를 고려하여 위험 순위를 세밀하게 선정하기 위해 퍼지 TOPSIS 기법을 적용하였다. 그 결과, 위험 등급은 47개 그룹으로 구분할 수 있었고, 동 엔진 시스템의 운용 중 가장 위험도가 높은 위험요소는 LPG 공급 라인 유지 보수 중 가스 누출로 분석되 었다. 본 연구에 제안된 기법을 LPG 공급계통 등 다양한 설비에도 적용하여, 향후 LPG 추진 선박의 안전 기준 마련을 위한 위험성 평가 의 표준절차로 활용할 수 있기를 기대한다.
PURPOSES : Unlike European standards, domestic performance assessment standards for truck mounted attenuators (TMAs) was first stipulated in 2014 using the NCHRP Report 350 of 1993 as the standard instead of the 2009 MASH of the United States. The purpose of this study is to present an improvement in the domestic performance evaluation criteria for TMAs..
METHODS : Considering the latest TMA performance evaluation standards in the U.S. and Europe, domestic performance evaluation criteria must improve stipulations related to impact speeds, impact conditions, impact cars, and support trucks. The performance change in the TMAs according to the variation in the impact speed, impact condition, impact vehicle, and support vehicle was investigated using finite element analysis (FEA).
RESULTS : The TMA for an impact speed of 100 km/h showed a limit to the safety of the occupants of the collision vehicle and workers on the road for a collision speed of 120 km/h. The safety of the workers on the road was also not guaranteed for the collision of the remaining 73.8% of vehicles that exceeds the maximum impact car weight of 1,300 kg, the lower 26.2% of the total mass composition of domestic passenger cars. In addition, a TMA that satisfied only the conditions under which the vehicle was hit head-on to the center of the TMA did not reduce the risk of a secondary collision of the impact vehicle. Furthermore, the safety of workers on the road was not guaranteed when a travel distance of a support truck of 10 tons or more was applied to a work vehicle of less than 10 tons.
CONCLUSIONS : To improve the safety of road traffic, a performance level corresponding to an impact speed of 120 km/h was added to the domestic TMA performance evaluation standard, and the eccentricity and oblique collision conditions were mandatory. Furthermore, the maximum impact vehicle weight of 1300 kg was raised to 2000 kg, and the test requester had to present support trucks of lower and upper weights such that TMA mounting trucks of various weights could be used.
Quality standards of activated carbon for gas-phase applications have been deleted from the Korean national standard list since 2007, and the iodine adsorption test is the only measure currently used for quality assurance. This study was performed to propose a suitable test method and a quality standard for gas-phase activated carbon. The "1/2 saturated vapor adsorption" test has been developed as a simple and convenient method to determine the adsorption capacity of activated carbon. In this study, the developed test method was evaluated using model VOCs including toluene, methyl ethyl ketone (MEK), and ethyl acetate (EA). A virgin activated carbon revealed adsorption capacities of 344mg/g, 322mg/g, and 328mg/g for toluene, EA, and MEK, respectively, and the adsorption capacity for a mixture of the three VOCs was 334 mg/g. When a regenerated activated carbon was applied, the adsorption capacities dramatically decreased to 62 mg/g, 52 mg/g, and 61 mg/ g for toluene, EA, and MEK, respectively. In addition, the 1/2 solvent vapor adsorption tests using 13 different specimens of activated carbon showed that their capacities were closely related to the iodine adsorption numbers, and this study suggested the adsorption capacity of 300 mg/g as a new quality standard. The novel test method and its standard may help to guarantee the quality of gas-phase activated carbon used for VOCs abatement processes.
본 연구는 해양시설의 HNS 배출허용기준 체계에 적용 가능한 사회적 영향인자 평가방법 및 절차를 도출하는데 목적이 있다. 인천광역시 소재 해양시설 71개소로 대상으로 기업규모에 따라 대기업, 중견기업, 중소기업, 소기업으로 구분하였고, 신규 기술도입비용 은 5년간 분산하여 적용하는 경우로 추산하였다. 분석결과는 다음과 같다. 첫째, 산업분야 항목에서는 경영상부담정도를 나타내는 지표 중 매출액감소 1점, 영업이익률감소 평균 3.5점, 도산가능성 2.7점으로 평가되어, 평균 2.7점으로 ‘영향있다’로 평가되었다. 둘째, 지역경제 항목의 평가지표 중 주민보건비지출부담 4점, 관광수입손실액 4점, 어업생산량감소 2점 등 전체 평균 3.3점으로 ‘영향크다’로 평가되었 다. 평가결과 산업적인 면에서는 소기업, 중기업, 대기업 간에 미치는 영향편차가 큰데, 대기업은 영향이 거의 없었고, 소기업은 영향을 크게 받는 것으로 나타났다. 지역경제면에서는 주민보건비지출부담, 관광수입감소, 어업생산량감소 등이 지역경제에 미치는 영향은 두가 지로 구분하여 볼 수 있는데, 지역전체 GRDP에 미치는 영향은 매우적지만, 해당 종사자나 주민 개인에 미치는 영향은 영향이 큰 것으로 나타났다.