• 화약ㆍ발파
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• 제22권1호
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• pp.75-80
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• 2004

최근 도심지의 가속화에 따라 시가지 인근에서의 암반굴착이 활성화되고 있으며, 특히 보안을 요하는 구조물에 근접한 발과 또는 가동중의 설비 가까이 에서 발파굴착을 실시해야하는 등 주변환경을 충분히 고려하여 진동, 소음 및 비산을 효과적으로 제어할 수 있는 발파기술이 요구되고 있다. 이와 같은 배경에서 미진동 발파굴착을 위하여 콘크리트 파쇄기, 팽창성 파쇄제 등이 개발되어 실용화되고 있다. 국내에서는 (주)한화가 콘크리트 파쇄기(Finecker)를 개발하여 공급해 왔으며, (주)고려 노벨 화약에서는 저폭속(2,000 m/s) 화약을 2중의 Air Gap을 이용하여 진동 및 소음 제어하는 미진동 발파용 화약(Kinecker)을 출시하여 공급하고 있다. 이에 Kinecker의 원리와 특징 그리고 현장적용 사례 및 발파패턴을 소개하고자 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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• pp.73-79
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• 1996

우리나라와 같이 철도의 운행위치와 소음 피해를 받는 수음자 간의 거리가 인접되어 있는 경우, 소음의 전파특성은 과도형상을 나타내는 구간에 속하게 되어 전파중에 나타나는 지표면의 다양한 물리적, 현상과 경계면 등의 이피던스 값등이 많은 영향을 끼치게 된다. 본 연구에서는 철도소음의 소음원 자체에 대한 모델링 기법과, 자유공간을 전파할 때 나타나는 거리감쇠 효과 등을 고려한 음향학적인 연속선음원 및 유한 불연속 선음원 등에 대한 검토가 이루어졌고, 특히, 소음원의 크기에 비교하여 수음자의 위치에 따라 저감되는 음향전파특성을 설명하였다. 또한, 유한한 길이를 가지고 있는 철도차량의 소음원 모델을 이용하여 향후 국내에서 운행되리라 예상되는 고속철도의 음향파워를 산출하였다. 산출된 음향파워로부터 철도변의 소음분포를 도출하였으며 고속철도의 경우 운행시 소음피해가 어느 정도인지를 예상하였다.

• 한국소음진동공학회논문집
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• 제15권8호
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• pp.980-987
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• 2005

It is very difficult to reduce ambient noise level in the downtown. The best method is to improve the sound amenity of the districts, considering concept of soundscape. This study aims to survey the effect of introducing sound and masking to reduce the background noise level. We carried out the evaluating test for 18 introducing sounds varied S/N ratio(-5, 0, +5) in the city riverside. In these test, subjects evaluated the sound environment with five bipolar adjective scales. It was evaluated that introducing sounds improved the sound environment, and that S/N +5 dB was very appropriate to mask the background noise. But the hearing level was suggested to be S/N 0 dB or less.

• 한국소음진동공학회논문집
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• 제14권1호
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• pp.64-72
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• 2004

In this paper. we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The motions of the ring are electro-statically derived. sensed and balanced by electrodes. The equations of motion are formulated. The measuring method of angular velocities by force-to-rebalance is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.603-606
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• 2005

This study is to make good acoustic environment around Gwang-ju riverside and performed survey and measurement of soundscape. The survey was focused on the types of sound producing. The results of measurement and analysis are as follows: 1) The types of sound at reverside were twenty and the Leq(equivalent noise level) was ranging from 50 dB(A) to 76 dB(A). The dominant sound was road traffic noise. 2) In the upperstream and the downstream, the sound of wind, bird and water was observed. 3) In the inner city, the water sound was produced by the difference of the height of the weir to mask the road traffic noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.607-610
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• 2005

It is very difficult to reduce traffic noise level in the downtown. The best method is to improve the sound amenity of the districts, considering concept of soundscape. ?his study aims to survey the effect of introducing sound and masking to reduce the background noise level. We carried out the evaluating test for 18 introducing sounds varied S/N ratio(-5, 0, +5) in the city riverside. In these test, subjects evaluated the sound environment with five bipolar adjective scales. It was evaluated that introducing sounds improved the sound environment and that S/N + 5dB was very appropriate to mask the background noise. But the hearing level was suggested to be S/N 0 dB or less.

• 소음진동
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• 제6권3호
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• pp.287-296
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• 1996

A virtual work form of flexible multibody dynamic formulation with rotary inertia has been derived. For the analysis of large flexible multibody systems, deformation modal coordinates have been employed to represent coupled motion between gross and vibrational motion. For the efficient evaluation of the entries in the mass matrix, a flexible body has been treated as a collection of mass points. The rotary inertia was generated from the consistent mass matrix in a finite element model. Deformation mode shapes were obtained from finite element analysis. Bending and twisting vibration analyses of a cantilever have been carried out to see rotary inertia effects. A space flexible robot simulation has been also carried out to show effectiveness of the proposed formulation. This formulation is effective to the model that consists of beam, plate, or shell element that contains rotational degree of freedom at the nodal point. It is also effective to the flexible body model to which a large lumped rotary inertia is attached.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1991년도 춘계학술대회논문집; 한국해사기술연구소, 대전; 1 Jun. 1991
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• pp.91-93
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• 1991

DARBS는 저널베어링 및 구름베어링에 지지되어 있는 회전체-베어링계에 대한 동력학적 해석을 수행하는 프로그램이다. 해석에는 유한요소법(finite element method)을 이용하며 선회속도(whirl speed), 모우드 형성(mode shape), 임계속도(ciritical speed) 그리고 비동기 가진응답(asynchronous response)등에 대한 해석결과를 제공한다. 본 프로그램의 주된 특징은 람다 행렬(lambda matrices)의 개념을 도입하여 비동기 가진응답의 해석에 적용하 고, 베어링 상수와 자이로 효과와 같은 회전속도 의존성에 대하여 체계적인 접근방법을 사용했다는 점이다. 본 프로그램은 IBM PC 및 호환 기종에 적 합하도록 개발되었으며 기본적인 출력장치를 지원하는 S/W가 포함되어 있 다. 또한 대화식 데이타 입력과 메뉴처리방식을 채택하여 사용하기 편리하게 하였으며, 오류발생시 메세지가 나타나 오류수정을 용이하게 하였다.

• 한국소음진동공학회논문집
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• 제25권1호
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• pp.40-47
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• 2015

Dynamic response of any small structure is always affected by the mass of the attached accelerometer. This paper predicts the natural frequencies and frequency response functions by removing the mass loading effect from the accelerometer. This mass loading is studied on a simple cantilever beams by varying the location of accelerometer. By using sensitivity analysis with iteration method, accelerometer mass and location are obtained. The predicted natural frequencies of the small cantilever beam without the accelerometer's mass show good agreement with the structural re-analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.929-934
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• 2007

Various methods to improve the planetary gear noise in the vehicle were introduced. And planetary gear systems were analyzed Therefore a common thing among the different planetary gear systems which generate the gear noise in the vehicle was founded. Most importantly, a frequency versus vibration level map was introduced and a predictive method, which is considering the masking effect, to design the planetary gear sets in the concept design stage was described.