• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.04a
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• pp.100-105
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• 1994

본 연구에서는 변속기 중립상태에서 클러치 설계 인자인 비틀림 스프링과 건마찰에 의해서 클러치에 나타나는 히스테리시스, 그리고 클러치 디스크의 정적처짐을 발생시키는 드래그토크(drag torque)가 클러치의 동적인 거동과 기어래틀에 미치는 영향을 분석하고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.542-543
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• 2010

• Journal of KSNVE
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• v.9 no.5
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• pp.936-942
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• 1999

Unstable torsional vibration on the marine ship's propulsion shafting system with diesel engine occurred due to a slippage of multi-friction clutch which was installed between increasing gear and shaft generator. In this paper, the mechanism of this vibration was verified via torsional, whirling, axial and structural vibration measurements of shafting system and noise measurement of gear box. And it was also identified by the theoretical analysis method.

• Journal of KSNVE
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• v.5 no.1
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• pp.85-93
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• 1995

The vibration of the dehydration process in a washing machine is important problem that affects the performance of products. In this paper, the upper structure of a washing machine is modeled as rigid body suspension system and, by numerical analysis, the amplitude of a spin basket and the transfer moment at a base plate are calculated. To examine the vibrational characteristics according to design variable change, the friction coefficient in anubber, the radius of curvature, the stiffness coefficient, initial length and locations of support springs are considered in the analysis. Experimental results are compared with those of analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.694-702
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• 2017

In the case of an elevated railway station, structure borne noise and vibration due to structural limitations allow the load and vibration from railway vehicles to be directly transmitted to the station structure, resulting in an increase in the number of civil complaints from customers and staff of the station. The floating slab track system, which is well known as one of the solutions for reducing the noise and vibration from elevated railway stations, usually contains rubber mounts or rubber pads under the railway slab which act as a damper. These types of device have the disadvantage that is difficult to predetermine the exact stiffness and damping ratio under the nonlinear loads resulting from train services. In this study, an isolator with a friction type of wedge is introduced, which can be applied to floating slab track systems and to be designed with precisely the required stiffness. Furthermore, a comparative analysis of the stiffness between the designed and experimental values is carried out, while the damping ratio, which is closely related to the friction wedge blocks, is deduced according to the train load condition. The performance tests of the isolator were conducted in accordance with the DIN 45673-7 standard which includes both static and dynamic load tests. The load conditions for the performance tests are designed to conform to the DIN standard related to the weight of the train and rail track, in order to perform vertical and horizontal load tests, so as to ensure the secure structural safety of the railway. Also, by checking the change aspect of the friction coefficients of the friction elements according to the loading rate, the vibration reduction performance of the friction type isolator with variable loading rate conditions is examined.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1469-1472
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• 2006

This paper presents experimental analysis of a friction-driven wheel responsible for generating wheel squeal. Squeal noise generating mechanism has been examined under the laboratory condition. Model rig of the rail and the wheel are made and influential parameters to squeal noise e. g. frictional force, normal force between the rail and the wheel, creep speed of the wheel have been measured and calculated. Negative damping characteristic curve are calculated currently. Necessary relating computational analysis has been carried on also.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.1
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• pp.1-6
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• 1975

The sea noise of moving trawl net was recorded by an underwater tape recorder which was set wireless, and was analyzed by a sound level meter and an octave-band analyzer. The frequency distribution of sea noise of the moving otter trawl net ranged from DC to 5000 Hz, and the dominant frequency zone ranged from 500 Hz to 700 Hz, and the maximum sound pressure is about 22 dB at the otter trawl net. The main sound source of the sea noise from the moving trawl net was found to be sea noise due to the resistance of the ground rope against the sea bottom.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.305-308
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• 2000

본 논문에서는 한국어에 나타난 외래어 중에서 외국어(영어/독일어)의 $[\int]$음이 어떻게 인식되고 해석되었는지를 살펴보았다. 특히 본 논문에서는 $[\int]$음의 영어와 독일어 발음과 한국어의 대응되는 분절음이 일대일 대응을 이루고 있지 못하다는 것을 보이고 이런 대응관계를 설명하기 위해 어떤 정보가 필요한지에 대해 살펴보았다. 즉, 독일어와 영어에서 음절의 말음으로 쓰인$[\int]$음이 한국어에서는 [쉬/시]로 인식되는데 반해 본토어에서 $[\int]$음이 음절초음의 일부로 사용된 경우에는 한국어의 외래어에서 (슈)로 화자에게 인식되고 또 문자로 표현된다 따라서 본 논문에서는 음절초음의 일부로 나타나는 외국어의 $[\int]$음과 음절말음으로 나타나는 외국어 $[\int]$음의 음성학적 기호를 분석해보고 한국어에서 서로 다른 표면형을 형성하는 이유가 본토어의 (음절 초음/말음이라는) 음운론적 특성에 기인하는 것인지 혹은 현재까지 우리가 알고 있지 못했던 $[\int]$음의 발음 위치에 따른, 즉 동시조음(coarticulation) 현상 때문에 생긴 변이음 때문인지에 대한 규명을 시도하였다. 외국어 화자의 발성실험을 통해, 한국어에서 /쉬/로 인식되는 독일어와 영어의 $/\int/$음은 /슈/로 인식되는 $/\int/$음보다 마찰소음의 peak frequency가 높거나 지속시간이 길게 나타났다 이런 결과를 근거로 영어와 독일어의 $/\int/$ 음이 한국어의 /쉬/음과 /슈/음으로 구분될 때 사용되는 음성자질은 크게 2가지, 즉 마찰소음의 peak frequency와 지속시간이며, 둘 중 한가지만 있어도 구분은 가능하나 이 2가지가 동시에 존재할 때 /쉬/음과 /슈/음의 구분이 현저히 용이해진다는 가설을 세워보았다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.255-261
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• 2002

A four-degree of freedom model is suggested to understand the basic dynamical behaviors of the normal interaction between two masses of the friction induced normal vibration system. The two masses may be considered as the pad and the disk of the brake. The phase space analysis is performed to understand complicated in-plane dynamics of the non-linear model. Attractors in the phase space are examined for various conditions of the parameters. In certain conditions, the attractor becomes a limit cycle showing the stick-slip phenomena. In this paper, on the basis of the in-plane motion not only the existence of the limit cycle but also the size of the limit cycle is examined o demonstrate the non-linear dynamics that leads the unstable state and then the normal vibration is investigated as the state of the in-plane motion For only one case of the system frequency(two masses with same natural frequencies), the propensity of the normal vibration is discussed in detail. The results show an important fact that it may be not effective when too much damping is present in the only one part of the masses.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.7 s.124
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• pp.649-661
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• 2007

Friction-type reinforcing members(FRM) to enhance the resistance to wind loads of a transmission tower through both stiffness strengthening and damping increase are energy dissipation devices that utilize bending deflection of a tower leg. In this paper, the hysteretic behavior of the transmission tower structure with FRMs was experimentally investigated through cyclic loading tests on a half scale substructure model. Firstly, the variation of friction forces and durability of the FRM depending on the type of friction-inducing materials used in the FRM were examined by performing the cyclic loading tests on the FRM. Secondly, cyclic loading tests of a half-scale two-dimensional substructure model of a transmission tower with FRMs were conducted. Test results show that the FRM, of which desired maximum friction force is easily regulated by adjusting the amplitude of the torque applied to the bolts, have stable hysteretic behaviors and it is found that there exists the optimum torque depending on a design load by investigating the amount of energy dissipation of the FRMs according to the increase of torque.