• 한국진공학회지
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• 제12권1호
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• pp.51-54
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• 2003

아르곤 방전 기체의 음 글로우 영역에서 자발적 직동의 광검류 신호를 관찰하였다. 자발적 진동의 광검규 신호는 3 mA 보다 낮은 땅선 전류에서 나타난다. 준안정 준위의 인자 밀도 변화와 1s-2p 전이의 방출 세기를 동시에 측정한 결과, 자발적 진동 신호를 발생시키는 메커니즘 중의 한 가지는 느린 전자의 충돌에 의한 준안정 준위 원자의 단계적 이온화이다.

• 한국소음진동공학회논문집
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• 제17권8호
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• pp.726-735
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• 2007

Inside the factory buildings of aprecision industry (which produces semiconductors or TFT-LCD), thousands of vibration-sensitive precision equipments operate in the clean rooms. Various utility equipments that are installed around them for proper operation cause various sources of noise and of vibration to exist inside the clean rooms and thus deteriorate the noise and the vibration environment within. In this study, we check if the existing transient vibration phenomenon is caused by the vibrations that arise from operating the utility installed near these equipments; compare and evaluate the vibration criteria of precision equipments regarding the transient vibration phenomenon; and check the efficiency of these criteria.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.332-336
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• 2004

To position precision machines accurately, linear motion (LM) guides having rolling elements can be used. For ultra-accurate positioning control of the precision machines, the understanding of the dynamic behavior of the LM guide at the macro and/or micro scales is most critical, but the research on this subject is rare. The objective of the present research is to observe the vibration phenomena of the LM guide. Bails are used as the rolling elements in this work. Several experiments show the nonlinear characteristics of the LM guide such as hysteresis behavior and force-dependent natural frequencies phenomena.

• 한국소음진동공학회논문집
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• 제12권1호
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• pp.65-72
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• 2002

Generally, there are laser operating equipments( aligner, stepper) and electronic microscope( SEM, TEM) as a high precision manufacturing and inspection equipment in semiconductor production companies, precision examination and measuring laboratories. Mostly, these equipments are characterized by projection and target part. The relative displacements between projection and target part are dominant roles in vibrational problem in these precision equipments. These relative displacements are determined by the position of incoming vibration and the difference of vibration response in projection and target part. In this study, the allowable vibrational limits are suggested and the vibrational reduction plans are proposed by measurement and analysis of vibration phenomenon in the Clean Room in PDP(plasma display panel) production building. The vibration performance is evaluated by comparison relative displacements between projection and target part before/after the vibration isolation plan.

• 한국소음진동공학회논문집
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• 제21권4호
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• pp.291-298
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• 2011

According to the developments of automobile industry, the technology to enhance noise, vibration and harshness(NVH) performance has been studying in a point of view of ride comfort and quietness. Especially the use of computer aided engineering(CAE) simulation tools such as finite element(FE) analysis allows engineers to efficiently evaluate NVH performance. This paper presents the method to bulid FE models for full vehicle including engine, transmission. suspension and steering system, also to evaluate vibration performance of full vehicle. The full vehicle model, which is discussed, is correlated with the result of the frequency response measurement in the case of the car shake performance for high speed driving.

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.1029-1034
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• 2004

Linear motion ( LM) guides having rolling elements have been used to position precision machines accurately. For ultra-accurate Positioning control of Precision machines, the understanding of the dynamic behavior of the LM guide at the macro and/or micro scales is most critical, but the research on this subject is rare. The objective of the present research is to investigate the vibration phenomena of the LM guide where balls are used as the rolling elements. Several experiments show the nonlinear characteristics of the LM guide such as hysteresis behavior and force-dependent natural frequencies phenomena.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.924-928
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• 2002

Response of the rail surface is an important factor for the train safety and comfortable travel, and evaluation of vibration at the area along a rail is an important factor for the vibration. The dominant method to reduce the vibration that reach the ground is installing vibration absorber between rall and the under structure. In this paper, we evaluated the vibration reducing effect of using vibration control sleeper pads to slave and earth at certain distance from the sleepers.

• 한국소음진동공학회논문집
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• 제12권2호
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• pp.161-169
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• 2002

Based on the analytic expression for the elasto-dynamic behavior of rotating shaft, the transfer matrix is formulated for the shaft element with uniform cross-section. Timoshenko beam theory is Introduced for modeling the behavior of shaft. Complex variables representing the displacement, slope, moment and shear force are used for deriving the transfer matrix between both ends of the shaft element. Simulation result obtained by applying the transfer matrix to a general rotor model is compared with the reference result and proved to be exact. Natural frequencies and the corresponding modes are analyzed with varying the bearing: stiffness. The generally used bearings are considered for discussions. and the bearing stiffness is shown to affect the vibration characteristics of rotor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.453-454
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• 2017

본 논문에서는 환경 시험 중 한가지 방법인 진동 시험(Vibration test) 프로파일을 적용하여 고출력 리튬이온18650 셀(cell)에 물리적인 진동을 가하고 진동 시험 전 후 고출력 리튬이온 18650 셀의 전기적 특성 기반 내부 파라미터를 추출하였다. 통계적 기법인 상관 관계 및 대응 표본 t 검정을 적용하여 내부 파라미터인 방전 용량(discharged capacity), 방전 저항(discharged resistance), OCV(open circuit voltage) 간의 관계 및 변화를 비교 분석하였다.

• 한국소음진동공학회논문집
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• 제18권1호
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• pp.35-46
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• 2008

Harmonic vibration characteristics for the general rotor model having a breathing crack are analyzed. Analyses are performed at the half critical speed ranges. The vibration characteristics are explained by using the additional slope and bending moment at the crack position and the influence coefficient showing the structural dynamic characteristics of the rotor. With the low crack depth the magnitude of the additional slope is kept constant even at the speed range at which the orbit magnitude is very sensitive to the rotational speed change. At this speed range the vibration is affected by the influence coefficient only. As the dynamic bending moment exceeds the static bending moment with the increase of crack depth. the additional slope affects the vibration amplitude of cracked rotor and the crack propagation rate increases.