Currently, there is no definitive regulation for the appropriate frequency of data sampling in water distribution networks, yet it plays a crucial role in the efficient operation of these systems. This study proposes a new methodology for determining the optimal frequency of data acquisition in water distribution networks. Based on the decomposition of signals using harmonic series, this methodology has been validated using actual data from water distribution networks. By analyzing 12 types of data collected from two points, it was demonstrated that utilizing the factors and cumulative periodograms of harmonic series enables similar accuracy at lower data acquisition frequencies compared to the original signals.

PURPOSES : The purpose of this study was to develop techniques for forecasting black ice using historical pavement temperature data collected by patrol cars and concurrent atmospheric data provided by the Korea Meteorological Administration. METHODS : To generate baseline data, the physical principle that ice forms when the pavement temperature is negative and lower than the dew-point temperature was exploited. To forecast frost-induced black ice, deep-learning algorithms were created using air, pavement, and dew point temperatures, as well as humidity, wind speed, and the z-value of the historical pavement temperature of the target segment. RESULTS : The suggested forecasting models were evaluated against baseline data generated by the above-mentioned physical principle using pavement temperature and atmospheric data gathered on a national highway in the vicinity of Young-dong in the Chungcheongbukdo province. The accuracies of the forecasting models for the bridge and roadway segments were 94% and 90%, respectively, indicating satisfactory results. CONCLUSIONS : Preventive anti-icing maintenance activities, such as applying anti-icing chemicals or activating road heating systems before roadways are covered with ice (frost), could be possible with the suggested methodologies. As a result, traffic safety on winter roads, especially at night, could be enhanced.

PURPOSES : This study introduces the use of instantaneous speed collected by in-vehicle sensing devices for space mean speed and time mean speed estimation. METHODS : Using probe vehicles’ instantaneous speed data and GPS location at each designated time interval enables analysts to calculate the link-based space mean speed and time mean speed for a certain time-space domain directly. This study proves the equations mathematically and compares the results of time mean speed using Wardrop’s equation and section average speed by trips. RESULTS : This study introduces the concept of link-based average speed using both time mean and space mean speed definitions. First, an unbiased space mean speed was explained for a roadway section can be calculated from high-resolution vehicle trajectory data without necessarily continuously tracking a vehicle. Second, this study proves that the average section speed by occupancy resulted in identical values to the true space mean speed formulation by Wardrop. In addition, the average section speed by trip was nearly identical to the time mean speed. CONCLUSIONS : Each section on a signalized intersection corridor yielded various speed distributions whose parameters varied as measurements were taken closer to the intersection proper. By exploring the space mean speed with speed distribution, the intersection impact area can be defined more accurately.

In this study, acoustic and viscosity data are collected in real time during the ball milling process and analyzed for correlation. After fast Fourier transformation (FFT) of the acoustic data, changes in the signals are observed as a function of the milling time. To analyze this quantitatively, the frequency band is divided into 1 kHz ranges to obtain an integral value. The integrated values in the 2–3 kHz range of the frequency band decrease linearly, confirming that they have a high correlation with changes in viscosity. The experiment is repeated four times to ensure the reproducibility of the data. The results of this study show that it is possible to estimate changes in slurry properties, such as viscosity and particle size, during the ball milling process using an acoustic signal.

가상현실 콘텐츠는 ICT 기술의 발전과 5G의 고용량 전송, 빠른 속도의 네트워크 서비스가 상용화로 2019년 빠른 성장을 하고 있다. 하지만 가상현실 콘텐츠의 사용성 평가에 대한 기준과 연구는 미흡한 실정이다. 본 연구에서는 가상현실 콘텐츠를 사용하는 사용자의 반응과 상태를 측정 할 수 있는 객관성이 있는 데이터에 관한 연구를 진행한다. 연구의 방법으로는 가상현실 게임 콘텐츠 사용자의 실시간 인체정보 수집 프로세스를 설계하고의 변화를 비교·분석하였다. 이를 위해 인체정보 측정에 아이트래킹을 통한 시선 정보와 심박수 데이터를 수집하고 분석하여 시각화 솔루션을 설계하고 프로토타입을 구현하였다. 가상현실 게임 콘텐츠 사용자 인체정보 데이터를 기반으로 한 사용성 평가에 대한 가이드를 제안한다. 향후연구로는 다양한 인체정보 측정 및 프로토타입의 고도화에 있다.

본 논문에서는 국제해사기구의 데이터수집 시스템 도입에 따른 MRV 지원 및 국제해운 에너지 효율 포탈 시스템에 대한 기술적 검증을 수행하였다. 데이터 수집 시스템과 연료 사용량 데이터 수집 방법론을 포함하는 SEEMP 가이드라인의 주요 내용을 검토하고, EU MRV와 차이점을 분석하여 MRV에 대한 국내 해운선사의 대응전략을 제시하고 이에 대한 MRV 지원시스템의 기술적 적합성을 검토하였다. MRV 지원시스템은 배출량 데이터를 원시단계에서 최종단계까지 통합 관리함으로서 검증을 위한 비용과 업무 효율성을 높일 수 있으며, 현재 해운선사의 보고절차를 유지하면서 데이터 변환 기능을 통해 표준양식으로 배출량 데이터를 수집하고 보고 할 수 있다. 또한, 포탈시스템에 대한 접근권한을 구분하여 해운선사의 데이터 수집과 보고, 검증자의 데이터 검증업무를 지원할 수 있으며 전자적인 방법으로 보고서 제출이 가능하여 MRV 국제 규제에 대한 대응이 가능하다.

In this study, prototype DAU with LoRa wireless communication module is designed and manufactured. Also, the customized software is developed for the automatic data transmission to end-user from ThingPlug server of SK telecom LoRa network. For verification of the developed wireless monitoring system, DAU was installed on bridge construction site. The reliability of data and operational stability was evaluated by comparison with data from conventional monitoring system.

In this study, the bridge management system framework for the application of UAV collection data was proposed. The framework of UAV Bridge Management System(UBMS) is designed based on algorithm of Bridge Management System(BMS), administered by MOLIT. The UAV Bridge Management System will help facility managers to conduct safety diagnosis by providing rapid procedure.

This study was conducted to construct a DNA marker database for 38 plum varieties collected in Korea using simple sequence repeat (SSR) markers. A set of 61 SSR primer pairs was tested to select polymorphic SSR markers between 8 varieties. Among the 61 primer pairs, 21 showed polymorphism, reproducibility and easy scoring. The genetic relationship between the 21 SSR markers and 38 varieties was analyzed. A total of 210 polymorphic amplified fragments were obtained with the 21 SSR markers. Three to seventeen SSR alleles were detected for each locus, with an average of 10.0 alleles per locus. Average polymorphism information content (PIC) was 0.758, with a range from 0.549 to 0.870. A total of 210 SSR marker loci were used to calculate Jaccard’s distance coefficients for cluster analysis by an unweighted pair-group method with arithmetical average (UPGMA). The genetic distance ranged from 0.06 to 1.00 in 38 varieties. Out of 38 plum varieties, 32 were identified using the 21 SSR markers. Therefore, these SSR markers may be employed to complement distinctness, uniformity, and stability (DUS) tests or as potential tools to solve seed disputes regarding plums.