• 한국음향학회지
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• 제35권4호
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• pp.288-294
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• 2016

타이어와 휠가드 사이의 공간은 타이어 패턴음의 전달경로가 된다. 본 논문에서는 타이어-휠가드 공간에서 발생하는 음향현상을 음장모드 분석과 휠 가드 표면에서 음압분포 가시화를 통해 규명하였다. 타이어 패턴음 저감을 위해 음향학적 댐퍼 역할을 수행하는 캐비티를 휠가드 표면상에 적용하였다. 실내소음은 2 dB(A) 감소하였는데, 본 연구에서 다룬 소음저감방법은 완성차 단계에서 원가/중량의 증가없이 실내음질을 개선하는 효과적인 방안이 될 것이라고 판단된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.830-835
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• 2004

In railway systems, the performance of turnout is one of the most important factors to improve the train's speed. Standard turnout, in which one track is split in main track side and turnout side. Because the main track side remains linear, speed restriction can be alleviated while train pass the main track side. The factors of speed restriction in main track side are strength of crossing and tongue rail, wheel back side pressure of guard rail and wing rail. In this study, we measured wheel back side pressure of guard rail to compare improved turnout with present turnout. In result, the wheel back side pressure of improved turnout was lower than present turnout, so its performance was proved.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.12-18
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• 2014

This paper describes about the development of new concept's rear wheel guards for the reduction of Road Noise in the passenger vehicle using test. The new wheel guards are proposed by various frequency chamber concept and different textile layers concept. Two wheel guards were verified by small cabin resonance test and vehicle test. Through new developing process without vehicle test, Result of road noise will be expected when new concepts and materials of wheel guard is applied into automotive vehicle. As a result of the application of Aimed Helmholtz and Multi-layers concept, this paper classifies the road noise, cost and weight are reduced by new concepts and the solutions are adopted into the 2 cars.

• 대한기계학회논문집A
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• 제33권6호
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• pp.545-551
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• 2009

A small guard robot working indoors or outdoors can be used to report various information on its environment to an operator. The guard robot should be small-sized and lightweight to increase its portability. In addition, it should be able to overcome a relatively high obstacle to cope with various situations. To satisfy these requirements, this paper presents a small robot equipped with a novel hybrid wheel and track mechanism that can select wheels or tracks depending on the situation. The robot folds the tracks into the body in the wheel mode and only wheels are active with the tracks immobilized, which results in the fast moving speed. In the track mode, the tracks are extended to keep in contact with the ground. Furthermore, this research proposes the belt length maintenance mechanism by which the belt length is kept constant in either the wheel or track mode. Various experiments demonstrate that the proposed robot can move fast by using wheels on the smooth terrain and overcome obstacles by using tracks on the rough terrain.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1108-1114
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• 2009

Mobility is one of the most important features for a guard robot since it should be operated in rough places. A wheel-based mobile robot capable of jumping is an appropriate structure for a guard robot because it can easily satisfy the requirements for small guard robots. The jumping robot can reach a higher place more rapidly than other locomotion methods. This research proposes a small robot equipped with the jumping mechanism based on the conical spring with the variable length endtip. The variable length endtip enables the independent control of the jump force and jump angle which are related to the jump height and jump distance, respectively. Various experiments demonstrated that the proposed jumping mechanism can provide the independent control of jump force and jump angle, and improve the mobility of a small robot to overcome an obstacle. Furthermore, a combination of the jumping mechanism and the PSD sensor to measure the distance to the step enable the jumping robot to autonomously climb stairs.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.1115-1118
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• 2015

전기모터 구동 방식의 2륜 전기 차량은 공항, 항만 등에서 경계형 정숙 차량으로 좁은 실내를 이동하는데 많이 사용되고 있다. 이런 2륜형 전기 차량은 밧데리로 구동되며, 전/후진 및 회전 제어에 있어 여러 센서 및 핸들 조작 장치를 이용하는 제어 장치를 사용한다. 본 연구에 있어서는 탑승자가 별도의 손잡이형 회전제어 장치를 사용하지 않고도 두발의 무게 중심 만을 이용하여 회전하는 센서 인터페이싱 전자 제어 장치를 설계한다. 코너링 회전 시 탑승자의 안전성을 고려하는 설계라 할 수 있다.

• 대한기계학회논문집A
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• 제37권6호
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• pp.723-730
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• 2013

기존선에서의 속도향상을 저해하는 요인은 매우 다양하지만, 그 중 분기기 통과속도 제한규정을 가장 대표적 사례로 손꼽히고 있다. 현재, 기존선 분기기의 직선측 최고 통과속도는 일반 선로의 차량 최고 주행속도에 비하여 낮은 속도로 제한되어 운행하고 있으며 분기기내에서 주행속도를 제한하는 것은 분기기 통과 시 철도차량의 주행안전성을 확보하는데 목적을 두고 있다. 본 연구에서는 대구도시철도공사의 분기기 가드레일에 대한 형상 변경사례를 기반으로 하여, 분기기에서의 차륜/레일 형상에 따른 기하학적 관계식을 이론적으로 검토하였으며, 개발한 VI-Rail 분기기 해석기법을 통하여 F10/F12 분기기에서의 가드레일 길이 변화에 따른 주행안전성 해석을 수행하여 그에 따른 영향을 살펴보았다.

• 한국안전학회지
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• 제38권1호
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• pp.42-54
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• 2023

Mobile scaffold is used as a work platform in construction sites. According to industrial accident data, 10 fatalities occur annually on average due to falling from mobile scaffold in construction sites. To prevent such fatal accidents, safety standards must be improved by analyzing the causes of fatal accidents related to mobile scaffold. Accordingly, we analyzed domestic and international safety standards for mobile scaffold and analyzed the fatalities (117 persons) caused by mobile scaffold accidents in domestic construction sites during 2011-2020 and found that fall, overturn, and collapse accounted for 88% (103 persons), 10.3% (12 persons), and 1.7% (2 persons) of fatalities, respectively. The main causes of fatal accidents were found to be non-installation or insufficient installation of safety rails and outriggers and incorrect sequence of work. Based on the analysis results, we proposed strategies for improving the safety standards, such as the use of advanced guard rails and wheel-attached outriggers, to enhance the safety and field applicability of the mobile scaffold. Technology development and improvements in the safety standards for the use of mobile scaffold will aid in the prevention of fatal accidents caused by mobile scaffold.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.88-91
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• 2007

Turnout system is a mechanical installation enabling trains to be guided from one track to another which is consists of point blades, common crossing and guard rail etc. These structural feature causes vibration, noise and damages while railroad car wheel is passes by. A tilting train is a train with a tilting mechanism that enables increased speed on regular railroad tracks. The aim of this paper is to study a characteristics of the shock-vibration and noise of tilting and existing train passes by turnout systems. To analyze and assesment, noise and vibration measurement was carried out at the Naesu-station of Chungbuk-line which equipped with cast manganese crossing and built-up crossing and Illo-station of Honam-line which equipped with cast manganese crossing.

• 한국철도학회논문집
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• 제8권1호
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• pp.93-100
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• 2005

The turnout system is typical railway facility to be in the way of conventional railway line's speed-up. The KNR(Korean National Railroad) has a speed limit regulation (130km/h) for the passing the turnout to guarantee a safety. This research had been performed to confirm the propriety of this regulation by using experimental and analytical way before it was carried out. The reasonableness of the speed-limit regulation was judged base on the several experiments. It was proved that the regulation was not useless as it had been regarded and very important guide at least up to now.