• 한국소음진동공학회논문집
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• 제15권4호
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• pp.465-473
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• 2005

The impact sounds, generated by the walking of people, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. The characteristics and level of this impact noise depends on the object striking the floor, on the basic structure of the floor, and on the finish materials of floor. The focus of this paper is to investigate the amount of improvement impact sound pressure level according to the change of the composition method of ceiling and wall. For this purpose, we tested impact sound pressure level of several cases which is the inserting of mineral wool, the increase of the thickness of air layer, the using of anti-vibration rubber in ceiling and attach the mineral wool on wall in the Floor Impact Sound Test Building of KICT. The results show that the composition method of ceiling and wall is more effective in the reduction of light weight impact sound specially in 125Hz and 250Hz.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.261-264
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• 2004

Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. The character and level of impact noise generated depends on the object striking the floor, on the basic structure of the floor, and on the floor covering. This study base on the evaluate of isolation performance of impact sound according to the installation of ceiling and wall. In this test, we measured the reduction of impact sound in the case of inserting absorption materials, increasing of the thickness of air layer and using anti-vibration rubber in ceiling, install of absorption materials in wall. The results of this study show that treatment of ceiling and wall have some reduction of the light weight impact sound and heavy weight impact sound.

• Composites Research
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• 제13권1호
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• pp.89-97
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• 2000

광섬유센서를 이용한 복합적층판의 피로손상 감지 및 진동측정, 그리고 스틸 보에 대한 충격위치 검출에 관한 연구가 수행되었다. 피로과정중의 신호는 복합재료 내에 삽입된 광섬유와 표면에 부착한 광강도형 광섬유센서, 그리고 스트레인게이지로부터 동시에 측정되었다. 진동감지 실험은 복합재료 보의 표면에 광섬유센서를 부착하여 자유진동 및 강제진동 신호를 취득하였다. 충격위치 검출에 관한 실험에서 충격위치는 충격에 의해 발생된 구조물의 진동이 두 센서에 도달하는 시간의 차를 이용하여 구할 수 있다. 광강도형 광섬유센서를 이용하여 반복 피로 신호를 잘 취득할 수 있었으며 스트레인게이지에 비하여 피로저항성이 우수함이 확인되었다. 광섬유센서는 갭센서와 동일하게 진동신호를 감지하였고 구조물에 가해진 충격위치를 비교적 정확히 검출할 수 있었다.

• 한국소음진동공학회논문집
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• 제15권5호
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• pp.542-549
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• 2005

Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance In residential buildings. Running and jumping impact sound by child are one of the most irritating noises in an apartment buildings. It's necessary to know that the impact power characteristics of real impact source in an apartment buildings. This study aims to Investigate the impact power characteristics and impact power time of running and jumping by child. This study carried out investigation through the 159 children in school. The results of this study is that jumping impact power is greater than running impact power.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.804-807
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• 2005

The characteristics of the standard floor impact sources and the human impact source were investigated. First, the mechanical impedance of the each source was evaluated. Second, the impact force exposure levels and impact sounds level driven by the each source were measured. The results showed that the mechanical impedance and impact force exposure level of the impact ball are the most similar to those of the human impact source among the standard impact sources.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.808-811
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• 2005

To use the impact ball as a new standard floor impact source, the objective and subjective properties of the impact bali were investigated. The results showed that not only the objective properties of the impact ball such as the Impact force exposure level, mechanical impedance but also the psychological parameters were more similar to those of the human impact than the bang machine. In addition, most of the subjects chose the impact bail sound as the most similar sound to the human impact sound in the auditory experiment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.265-268
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• 2004

Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. Running and jumping impact sound by child are one of the most irritating noises in an apartment buildings. It's necessary to know that the impact force characteristics of real impact source in an apartment buildings. This study aims to investigate the impact force characteristics and impact force time of running and jumping by child. This study cud out investigation through the 155 children in school. The results of this study is that jumping impact force is greater than running impact force but impact force time is lower than that.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.334-339
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• 1998

The free vibration analysis of the simply supported steel and composite cylindrical shells are investigated. The natural frequencies and mode shapes of the shell are experimentally obtained by impact testing using an impact hammer and an accelerometer. The effects of the material and geometry on the vibrational characteristics of the shell are examined. The experimental results are compared with the analytical and a finite element results. They showed good agreement with each other.

• 산업경영시스템학회지
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• 제22권52호
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• pp.43-52
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• 1999

In this study, the vibration damping characteristics of the powered hand tools transmitted in hand-arm system were examined and compared. The types of powered tools for the experiment are general typed drill, impact drill, grinder, and wire brush. To analyze the characteristics of vibration damping, the magnitude of acceleration of vibration on X, Y, and Z direction at tool, hand, wrist, and the joint between forearm and upper arm were measured respectively. The results indicated that impact drill generated the highest value of acceleration of vibration among the four types of tools used in the experiments. The highest value of the amount of acceleration of vibration was found in the direction of Y. And the amount of acceleration of vibration was significantly affected by the type of tool, type of work, and pushing forces. As become the more distant from the tool, the smaller the amount of acceleration of vibration. Also, the bigger the pushing force at the tool, the higher the acceleration of vibration.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.377-385
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• 1996

In the case of a precision equipment, it requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga class semiconductor wafers. This high technology equipments require very strict environmental vibration standard in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria are usually obtained either by the real vibration exciting test on the equipment or by the analytical calculation. the former is accurate but requires a great deal of time and efforts while the latter lacks reliability. this paper proposes a new method to solve this problem at a time. the permissible vibration level to a precision equipment can be easily obtained by analyzing a process of Frequency Response Function. This paper also demonstrates its effectiveness by applying the proposed method to finding the vibration criteria of a Computer Hard Disk Drive by impact Test.