• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.499-504
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• 2012

The high-speed train enjoys widespread acceptance as environment-friendly means of medium- to long-distance transportation. The pursuit of higher speed and lighter weight in railroad vehicles has engendered higher noise level. In particular, the environmental noise places many restrictions in the operation of high-speed railroad vehicles. This research investigates the effect of installing a skirt onto a high-speed train bogie with the top speed of 400 km/hr and using High Speed EMU for the purpose of reducing the environmental noise. In order to analyze the effect of the interior noise and environmental noise due to installation of the skirt, sound level is calculated using the Ray method and Statical Energy Analysis method. The numerical calculation predicts a reduction of approximately 2 dB in the environmental noise level, but at the cost of increase of approximately 2.5 dB in the interior noise level of the vehicle.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.216-217
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• 2016

본 논문에서는 Common Mode Noise가 저감된 계통연계형 단상인버터에서 파워 소자의 도통손실을 줄일 수 있는 방법을 제안한다. 제안하는 방법은 단상인버터의 (+)양의 구간과 (-)음의 구간의 전류 회생모드 시 MOSFET 소자를 turn-on 시키는 동기 정류 방식을 사용하여 손실을 저감한다. 제안한 방법의 효용성을 PSIM 모의해석을 통하여 입증 하였다.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2022년도 제66차 하계학술대회논문집 30권2호
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• pp.293-296
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• 2022

본 논문에서는 실제 주행하는 철도가 지나가는 터널에서 유발되는 안전사고 및 주변에 거주하는 주민들과, 서식하는 야생동물들에게 피해를 입힐 수 있는 소음과 진동을 감지하고, 철도가 터널을 운행하는 상황을 구현하여, 너털에서의 위험 요소들에 대한 상황 데이이터들을 센서를 통해 데이터 수집을 진행하고 다양한 위험 상황으로부터 실시간 감지를 통해 데이터들을 분석하고 적절한 상황 지원을 위한 실시간 인지시스템 모델을 설계하고 지원한다.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2023년도 제68차 하계학술대회논문집 31권2호
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• pp.233-236
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• 2023

본 논문에서는 주거지역에서 철도 운행으로 발생하는 소음, 진동, 미세먼지가 거주민들에게 입히는 피해를 최소화 하기 위해 소음, 진동, 미세먼지의 수치 위험도 기준을 정하고, 아두이노 센서와 모듈로 스마트 창문 및 공기 청정기를 제작한다. 센서를 통해 수집한 데이터가 기준치를 초과할 경우 창문의 개폐 또는 공기 청정기 시스템이 작동을 하도록 구현하여 소음, 진동, 미세먼지 피해를 최소화 하도록 구현하였다.

• International Journal of Railway
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• 제4권2호
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• pp.42-49
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• 2011

Today, rolling stock has become a fast and convenient mode of transportation and has witnessed increased demand. But the speed improvement has resulted in increased aerodynamic noise and therefore residential districts near the railroad tracks are exposed to ever increasing noise level. A study on methodologies for measuring and appraising rolling stock's environmental noise has therefore become an important area of endeavor. In the case of the environmental noise, there are no changes in tone so prediction can be made by reducing areas around the railway. The present study explores estimation of the noise around the railway using scale model, and the source of the noise has been investigated as well. The scale model of rolling stock will have to be able to measure high frequency noise and it is required to be generated in a short amount of time. Since popping a balloon or firing a gun fits this requirement the present study analyzed the characteristics of these two different noise sources. Measurement was made in a large vacant lot and the reflection due to the ground was also examined. The method proposed here can be used in the future for predicting the environmental noise of railway vehicles.

• 도로교통
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• 통권95호
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• pp.32-39
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• 2004

• 대한안전경영과학회지
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• 제21권3호
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• pp.17-21
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• 2019

With the development of public transportation, the use of subways as a means of transportation in the city center is increasing, so that vibrations and structural noises are emerging as a new environmental issues. This study can be used as a basis for research on subway safety and shock mitigation by applying vibration-proof mat.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2022년도 제65차 동계학술대회논문집 30권1호
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• pp.123-126
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• 2022

본 논문에서는 철도 교량 운행 상황을 가정하는 모형 철도를 사용하여 실제 철도 교량에서 발생할 수 있는 소음, 진동등 위험 요소로 분류될 수 있는 데이터들을 수집하고 수집된 데이터들을 활용하여 실시간으로 위험 요소로부터 발생할 수 있는 위험 상황들을 분류하고 적절한 조치들을 상황에 맞게 취할 수 있도록 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.711-716
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• 2011

Today, high-speed trains enjoy wide acceptance as fast, convenient and environment-friendly means of transportation. However, increase in the speed of the train entails a concomitant increase in the aerodynamic noise, adversely affecting the passenger comfort. At the train speed exceeding 300 km/h, the effects of turbulent flows and vortex sheddding are greatly amplified, contributing to a significant increase in the aerodynamic noise. Drawing a biomimetic analogy from low-noise flight of owl, a method to reduce aerodynamic noise at inter-coach space of high-speed trains is investigated. The proposed method attempts to achieve the noise reduction by modifying the turbulent flow and vortex shedding characteristics at the inter-coach space. To determine the aerodynamic noise at various train speeds, wind tunnel testing and numerical CFD (Computational Fluid Dynamics) simulation for the basic inter-coach spacing model are carried out, and their results compared. The simulation and experimental results reveal that there are discrete frequency components associated with turbulent air flow at constant intervals in the frequency domain

• 한국기계가공학회지
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• 제14권2호
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• pp.14-18
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• 2015

In recent years, world is faced with a transportation energy dilemma, and the transportation is almost dependent on a single fuel - petroleum. However, Hybrid Electric Vehicle (HEV) technology holds more advantages to reduce the demand for petroleum in the transportation by efficiency improvements of petroleum consumption. Therefore, there is a trend that lower gear noise levels are demanded in HEV for drivers to avoid annoyance and fatigue during operation. And meshing transmission error (T.E.) is the excitation that leads to the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in the whole gearbox. In this paper, the analysis of gear tooth profile and lead modification is firstly presented, and then, the different transmission error of no mesh misalignment and mesh misalignment under one loaded torque for the 1st gear pair of HEV gearbox was investigated and compared. At last, the appropriate tooth modification was used to minimize and compare the transmission error of the gear pair with mesh misalignment under the loaded torque.