In this study, the distribution characteristics of particulate matter (PM) in subway platforms were investigated, and the performance of hybrid filter systems was determined through the removal efficiency of PM according to various flow rates and filter structures. The hybrid filter systems were constructed in magnetic systems as (Magnet-Magnet (MM) filters and Magnet-Cascade (MC) filters). PM removal efficiencies of these filters were investigated at a subway platform for three days including weekdays and weekends. The compositions of collected PM were also analyzed. Based on the PM measurement in the subway platforms, it was confirmed that the operation of trains had a significant effect on the increase of PM concentration, and a large number of PMs were less than 1 μm in size. For the MC filter, the removal efficiency of PM1 based on the number of particles was up to 30.5%, demonstrating a relatively high removal efficiency in comparison with the MM filter. In terms of PM10, PM removal efficiencies of the MC filter with respect to the mass concentration and the number of particles were 48.3% and 14.5%, respectively. For the MC filter, it was found that the PM removal efficiency was enhanced with the increase in the flow rate. Moreover, the relatively large particle size PM (i.e., 7.5 μm - 10 μm) denoted a maximum removal efficiency of 97% in terms of the number of particles. All PMs collected by the filter were Fecontaining PMs. As a field experiment using the hybrid filter, the applicability of magnetic particle control technology was approved. Based on this result, it is expected that this study will be used as background research for the development of fine dust control technologies in a subway environment.

PS 강거더의 비선형, 비탄성 거동에 대한 편향부 효과를 조사하기 위하여 PS 시스템의 거동특성에 대한 실험적 및 이론적 연구를 수행한다. 이를 위하여 H빔, 편심을 갖는 직선 케이블, 정착부, 그리고 편향부를 갖는 4개의 시험체를 제작하여 2점 하중에 의한 파괴거동시험을 수행한다. 또한, 편향부가 없는 경우와 등간격으로 3개의 편향부가 설치된 경우의 PS 시스 템에 대하여 면내 변형이론을 새로이 정식화하고 symbolic 연산을 수행할 수 있는 메스메티카를 이용하여 비선형해를 구한다. 실험 및 이론적 연구의 타당성을 검증하기 위하여 박벽보요소, 강성이 매우 큰 보요소, 그리고 케이블-트러스요소로 구성되는 유한요소모델을 구축하고 비탄성해석을 수행하여 그 결과를 실험결과 및 해석해와 비교한다. 결과적으로 외부에 설치된 비부착 편향부로 인하여 H빔의 횡변위가 강하게 구속되어 PS 시스템의 강성 및 파괴강도는 편향부가 없는 경우와 비교할 때 크게 증가한다.

The electrical muscle stimulator (EMS) based human machine interface (HMI) free to mechanical constraint and muscle fatigue problems are proposed for force feedback in a virtual reality. The device was designed to provide force feedback up to 4.8 N and 2.6 N each to the thumb and forefingers. The main objective of the HMI is to make unnecessary mechanical structures to attach on the hand or fingers. It employs custom EMSs and an interface arranged in the forearm. In this work, major muscle groups such as extensor pollicis brevis (EPB), extensor indicis proprius (EIP), flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) are selected for efficient force feedback and controlled individually. For this, a human muscular-skeletal analysis was performed and verified. The validity of the proposed multi-channel EMS based HMI was evaluated thorough various experiments with ten human subjects, interacting with a virtual environment.