• 화약ㆍ발파
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• 제40권2호
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• pp.25-34
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• 2022

최근 터널 발파현장을 중심으로 정밀한 시차를 갖는 전자뇌관을 활용하여 시공성을 향상하는 사례가 증가하고 있다. 본 사례는 『수도권 광역급행철도 A노선 민간투자사업 제00공구』 현장에서 비전기뇌관과 전자뇌관을 혼용하여 시험발파를 수행한 사례로, 현장 주변 상업시설과 지하철 등 보안물건이 있어 발파작업 시 진동과 소음의 세심한 관리가 필요한 곳이다. 당 현장은 비전기뇌관으로 설계되었으나, 굴진율의 저하로 비전기뇌관과 전자뇌관을 혼용함으로써 굴진율을 향상하고 진동과 소음을 관리하고자 하였다. 시험발파 결과 굴진율이 약 85%로 목표치를 달성하였고 진동과 소음의 최대 측정값은 0.215cm/sec와 73.22dB(A)로 규제기준 이하로 계측되었다. 당 현장은 도심지에서 발파작업이 진행되는 만큼 계측관리 대상물을 지정하여 지속해서 진동과 소음을 관리할 필요가 있다.

• 자원환경지질
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• 제38권2호
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• pp.155-163
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• 2005

RR (Remote Reference)과 SNS (Signal Noise Separation) 기법을 도입하여 용인과 이천에서 측정된 지자기 전달함수를 분석하였다. RR 기법은 측정 사이트와 동시에 기록되는 원격참조 자료를 사용하여 자기장의 비상관 잡음 (un-correlated noise)을 제거하는 기법으로서 전달함수의 편향을 최소화한다. 한편 SNS 기법은 원격참조 자료가 잡음이 거의 없다는 가정을 바탕으로 신호에 의한 전달함수와 상관잡음(correlated noise)에 의한 전달함수를 분리하는 기법으로서, 측정 사이트에 상관잡음이 지배적인 경우에도 신호에 의해 전달함수를 성공적으로 추정할 수 있다. 본 연구에서는 자료의 질이 양호하다고 판단되는 이천을 원격참조 자료로 사용하여, 용인에서의 전달함수를 분석하였다. RR기법을 적용한 곁과, 단일 로버스트 추정(Single robust estimation)에서 나타났던 편향이 감소되었고, 주파수에 따른 전달함수의 연결성도 향상되었다. 잡음원에 대한 보다 정량적인 분석을 위해 SNS 기법을 적용한 결과, 주기 100초 이하에서 용인의 서쪽에 존재하는 잡음원의 존재를 확인하였다. 이러한 잡음원은 용인의 서쪽을 지나가는 국철, 고속철도 등의 철도 시스템에 의한 것으로 생각된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.754-760
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• 2008

For monitoring of railway structures, optical fiber sensors are very convenient. The fiber sensors are very small and do not disturb the structural properties. They also have several merits such as electro-magnetic immunity, long signal transmission, good accuracy and multiplicity of one sensor line. Strain measurement technologies with fiber optic sensors have been investigated as a part of smart structure. In this paper, we investigated the possibilities of fiber optic sensor application to the monitoring of railway structures. We expect that the fiber optic sensors have much less noises than electrical strain gauges because of electro-magnetic immunity while railways operate electric power of 22000 volts. Fiber optic sensors showed good durability and long term stability for continuous monitoring of the railway structures as well as good response to the structural behaviors during construction.

• 한국전자파학회지:전자파기술
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• 제6권7호
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• pp.37-47
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• 1995

본 논문은 도시전철에서 발생하는 전자파 잡음을 측정하여 확률통계적인 방법을 이용하여 모텔링을 하였다. 도시전철의 전자파 잡음의 측정을 위하여 자동 측정시스템을 구축하였고,9kHz 에서 30 MHz 까지의 자기 장, 30 MHz 에서 1,000 MHz 까지의 전기장을 측정하였다. 컴퓨터로 제어되는 측정시스템을 이용하여 국철과 지하철로 구분하여 각각의 진폭확률분포(APD: Ampli tude Probability Distribution)를 측정하였다. 측정된 APD 곡선은 6 개의 변수로 표현한 Middleton 의 방볍으로 해석하였다. 변수의 최적치를 빠른 시간내에 계산하기 위하여 합성 근사화 알고리즘을 사용하였다.

• 한국소음진동공학회논문집
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• 제12권7호
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• pp.527-533
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• 2002

A railway vehicle should be satisfied with the safety criteria and ride comfort of passengers. A bogie of railway vehicle Is composed of many suspension components, such as springs, dampers and etc.. that have an influence on the dynamic behavior of the train wish the wheel/rail profiles and track geometries. Therefore, it Is necessary for engineers to check the Interference between vehicle limit and construction limit with considering the vehicle's behavior, because when the vehicle is running on curved track, it should be have enough clearance from infrastructure for safely, spacially In a subway system. This paper explains the effective method of analysis for vehicle limit considering the vehicle dynamic behavior and reviews the problem of vehicle limit for the Korean Standard Urban Train. The results show that the vehicle limit is over the construction limit when the Korean Standard Urban Train runs on the curved track with 180 m radius of curve.

• 한국항공운항학회지
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• 제28권4호
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• pp.171-175
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• 2020

The present and future cities are expanding, and the noise and environmental pollution in cities are getting worse day by day, causing saturation of road and subway traffic. As a result, citizens are spending a great deal of time and money. The use of the sky as a measure to solve this problem has become a reality. However, airplanes that require airstrips and noisy helicopters are difficult to use in cities. As a solution, PAVs and UAMs that generate low noise and enable vertical takeoff and landing using electric energy, motor, hybrid, and hydrogen energy, are attracting attention, with its practicality being promoted in many countries. The development of urban environment and technology has led to the emergence of Personal Air Vehicle (PAV), Vertical Takeoff and Landing (eVTOL), and Urban Air Mobility (UAM) for shipping. Though currently at the level of testing, general commercialization of these air transport means is expected in the next five to fifteen years. This study suggests a plan on the application of human factors to the introduction of PAV and UAM.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2775-2781
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• 2011

Urban Transit Train Radio is Radio Communication system that is used official business as leading motive for train safety running among the train crew and the central control center and drive-caring-chamber on main line and branch line. This system is operated that organizes talking path on handset of terminal after the train crew receives audio and understands call voice on speaker of terminal at calling the train of the central control center. When the central control center calls the specific train uses all call radio form, the train crew doesn't recognize the call cause the train situation, noise and action as train control. So there is a delay response cause reset call at the central control center. This research discusses the management of subway radio system and describes the call the train system that recognize train call number of all-call used between the central control center and the train crew.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1894-1904
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• 2011

The Light Rail Transit (LRT) System which has medium transport capacity between subway and bus(5,000-25,000 persons per hour) is the most advanced transportation system. It has many benefits, cheap construction, operational costs through driverless and flexible route planning. Also, the rubber tired AGT (K-AGT) of various LRT has a rubber wheels and side guide. The side guide type has an many advantages. but occur a vibration and friction noise through contact between guide rail and wheel. Most of point that decreased comport is vibration thorough the guide contact. In this paper, It is purpose to improve the maximum running speed of rubber tired AGT localization bogie which is currently developed from 70km/h to 80km/h. To satisfy comport index of railway vehicle that is required in performance test. we examined coefficient of bogie suspension which is designed.

• 한국철도학회논문집
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• 제8권2호
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• pp.182-187
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• 2005

Air spring system was widely accepted for railway vehicle secondary suspension to reduce and absorb the vibration and noise. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestically developed productions are shown in good results. And to guarantee the adaption of air spring, the ride comfort and air pressure variation were measured in train test on subway line.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.722-725
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• 2005

Recently, ground-borne noise and vibration generated by underground transit system has been recognized as an important environmental problem. This study reviews several of the improved procedures that have been used to predict ground-borne vibration. At first, ground stiffness profile is examined by SASW test which is the most reasonable surface wave test. It is very important to acquire the exact ground stiffness profile at ground response analysis. At second, the train loading to act roadbed is calculated by using the real measured phase angle data. In finite element analysis, averaged acceleration method, infinite element, Rayleigh damping and 2-dimensional wave propagation analysis is performed.