• 한국건축시공학회지
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• 제7권3호
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• pp.75-82
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• 2007

A vibration in the building occurs by influences of the facility equipment and the structural system. As the building recently becomes higher and bigger, the vibration in the floor slab is issued. Specially, the vibration with $4{\sim}8Hz$ frequency is harder to control than any other range of frequency. This vibration easily affects human sensibility and often makes the resonance phenomenon by corresponding with the floor slab's natural frequency when people and heavy equipments move. Moreover, the permission regulations for the vibration of the building are established by building's purposes. However, it is not subdivided in detail and sometimes ambiguous to each client. Even though the vibration could cause negative influences in a research building, there is not the vibration criterion for a research building. Therefore, it is necessary to set up its own vibration criterion with the client before building and to keep checking this vibration criterion under the construction. This study proposes the reasonable control methods and the vibration criterion for floor slab's vibration which are adapted to the R4-project. The R4-project is a research building and a high-rise building also. Accordingly, this study could help to the next similar project in the design and the construction phase.

• 화약ㆍ발파
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• 제22권3호
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• pp.85-95
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• 2004

국가의 발파진동과 소음에 대한 규제 기준은 공학적인 기술검증 절차에 의해 설정되어져야 한다. 발파진동에 의한 공해는 인체에 미치는 영향과 구조물이나 시설물에 미치는 영향이 전혀 다르게 나타나므로 각각의 특성에 맞는 기술적인 검증을 거쳐 규제기준이 설정되어져야한다. 현재 국가에서 규정하고 있는 발파진동에 대한 규제 기준은 환경부의 소음 진동 규제법과 건설교통부의 터널시방서의 발파진동허용기준이 전부이다. 환경부의 발파진동 규제기준은 사람의 주거환경을 대상으로 설정하였으므로 인체에 대한 발파진동의 반응현상을 근거한 선진국의 연구자료와 법규정 등을 인용하여 부분적으로는 문제점이 있으나 비교적 타당성이 있는 기준이 설정되었다고 사료된다. 그러나 건설교통부에서 발파진동 규제 기준으로 제시한 터널시방서의 발파진동허용기준은 발파공학적인 기술특성을 알지 못한 상태에서 부실하게 규제 기준을 만들어 정상적인 발파 공사를 방해할 뿐만 아니라 선진국과 국내에서 지극히 정상적으로 발파 공사를 수행하고 있는 공법까지도 발파진동허용기준에 저촉되어 공법을 폐기해야하는 문제점이 발생되었다. 본고는 건설교통부의 발파진동허용기준에 대한 문제점을 지적하고 합리적인 발파진동허용기준에 대한 방안을 제시하고자 한다.

• 한국소음진동공학회논문집
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• 제12권6호
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• pp.453-460
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• 2002

In this paper, vibration criteria for fresh concrete are suggested considering relationship of strength and ages of concrete. Vibration criteria of fresh concrete subjected to construction vibration are not to be certain in abroad countries without question within a country. Before 12 hours cured, vibration criterion is suggested 0.25 cm/s. Used 4.0 cm/s by vibration criterion after 28 days. And the interval extent used relation with strength and ages of concrete. Vibration criteria proposed in this paper are thought may satisfy properties of fresh concrete as well as generally used those in domestic. Also, the actual ground vibrations due to pile driving have been measured, and data are analyze using the nitration equation applying to reliability index.

• 한국가스학회지
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• 제12권1호
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• pp.13-18
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• 2008

지진 및 외부 진동에 의하여 구조물에 발생하게 되는 진동량은 진동 속도와 피해규모가 비례하는 관계에 있음을 고려하여 일반적으로 진동속도로 나타내어진다. 본 연구에서는 진동 속도 기반의 구조물 진동기준을 검토하고, 이를 고려하여 도로 하부 매설 가스 강관의 안정성 평가를 수행하였다. 가스공사 주사용 배관인 762 mm API 5L Gr. X65 강관을 해석 대상 배관으로 선정하였으며 도로설계기준에 의하여 지반 매설 조건 및 DB-24 하중을 다양한 속도에 대한 시간 함수로 고려하여 재하하였다. 진동속도는 차량 진행 속도 80 km/h까지 증가하다가 이후 감소하는 경향을 보였으며, 차량 진행 속도 80 km/h에서 0.034 cm/s의 진동 속도를 보임으로서 진동 기준 대비 매우 작은 값임을 확인하였다. 또한 감쇄법칙을 적용하여 진행파의 속도를 분석한 결과, 차량 진행 속도 80 km/h에서 가장 작은 속도를 나타내었다.

• Structural Monitoring and Maintenance
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• 제4권3호
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• pp.221-236
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• 2017

In this study, the feasibility of vibration-based damage alarming algorithms are numerically evaluated for wind turbine tower structures which are subjected to harmonic force excitation. Firstly, the algorithm of vibration-based damage alarming for the wind turbine tower (WTT) is visited. The natural frequency change, modal assurance criterion (MAC) and frequency-response-ratio assurance criterion (FRRAC) are utilized to recognize changes in dynamic characteristics due to a structural damage. Secondly, a finite element model based on a real wind turbine tower is established in a structural analysis program, Midas FEA. The harmonic force is applied at the rotor level as presence of excitation. Several structural damage scenarios are numerically simulated in segmental joints of the wind turbine model. Finally, the natural frequency change, MAC and FRRAC algorithm are employed to identify the structural damage occurred in the finite element model. The results show that these criteria could be used as promising damage existence indicators for the damage alarming in wind turbine supporting structures.

• 한국산업보건학회지
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• 제18권1호
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• pp.1-10
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• 2008

In order to evaluate performance of anti-vibration gloves, it is necessary to measure the transmitted vibration to the hand and the applied forces at the same time while gripping the vibrating handle. In the study a system was developed to measure both the vibration and the forces. The system consists of a measurement handle with eight strain gauges and two accelerometers and a PC-based system with a software for signal processing, evaluation of the hand-transmitted vibration and for control of applied forces in the pre-determined range. The handle was installed on the vibration shaker which is strong enough so as not to be affected by dynamic coupling with the hand-arm. Whole procedure of ISO 10819:1996 to determine the vibration transmissibility of anti-vibration gloves was programmed into the system. As an example of the application, three subjects joined the test to get vibration transmissibilities of 9 anti-vibration gloves where each glove was tested twice a subject. Average and standard deviation of the corrected vibration transmissibility were also calculated. All tested gloves fulfilled criterion for M-spectrum($\overline{TR_M}$<1.0), but one glove fulfilled criterion for H-spectrum($\overline{TR_H}$<6.0),

• Smart Structures and Systems
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• 제18권4호
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• pp.819-837
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• 2016

The quality of vibration pattern reproduction of elastic structures by the modal expansion method is influenced by the modal expansion method and the sensor placement as well as the accuracy of measured natural modes and the total number of vibration sensors. In this context, this paper presents an improved numerical method for reproducing the vibration patterns by introducing a block-wise modal expansion method (BMEM), together with the genetic algorithm (GA). For a given number of vibration sensors, the sensor positions are determined by an evolutionary optimization using GA and the modal assurance criterion (MAC). Meanwhile, for the proposed block-wise modal expansion, a whole frequency range of interest is divided into several overlapped frequency blocks and the vibration field reproduction is made block by block with different natural modes and different modal participation factors. A hollow cylindrical tank is taken to illustrate the proposed improved modal expansion method. Through the numerical experiments, the proposed method is compared with several conventional methods to justify that the proposed method provides the improved results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.637-640
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• 2005

We propose a sound source localization method using the Head-Related-Transfer-Function (HRTF) to be implemented in a given platform. HRTFs contain not only the information regarding proper time delays but also phase and magnitude distortions due to diffraction and scattering by the shading object. Therefore, a set of HRTFs for any given platform provides a substantial amount of information as to the whereabouts of the source. In this study, we introduce new phase criterion in order to find the sound source location in accordance with the HRTF database empirically obtained in an anechoic chamber with the given platform. Using this criterion, we analyze the estimation performance of the proposed method in a household environment.

• 화약ㆍ발파
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• 제23권3호
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• pp.1-10
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• 2005

구조물의 발파진동에 대한 허용 수준 설정은 구조물의 반응 특성이 발파 진동의 특성과 전파 매질인 지반의 특성, 대상 구조물의 특성, 구조물의 기초 특성 등 여러 인파에 따라 달리 나타나므로 표준화된 기준을 적용하기는 쉽지 않은 일이다. 국외의 경우 영국, 독일, 스위스, 스웨덴과 같이 국가별로 허용수준에 대한 표준을 마련한 나라들도 있으며 아직 별도로 기준을 마련하지 않은 국가들도 많다. 우리나라는 통상 적용되고 있는 기준이 있으나 아직 국가 표준화는 되어 있지 않은 상황이며 민원 해결의 근거를 위한 합리적인 기준 마련의 필요성이 대두되고 있는 실정이다. 본 논문에서는 국가적으로 기준을 갖고 있는 미국, 영국, 독일, 스위스, 스웨덴 등의 사례와 개정 작업을 하고 있는 호주 및 브라질의 사례 분석을 통하여 다양한 형태의 기준들에 대한 특징을 파악하고 현행 사용되고 있는 국내 기준의 문제점을 고찰하였다.

• Geosystem Engineering
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• 제21권6호
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• pp.326-334
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• 2018

Underground water-sealed gas storage caverns have become the primary method for strategic storage of LPG. Previous studies of excavation blasting effects on large-scale underground water-sealed gas storage caverns are rare at home and abroad. In this paper, the blasting excavation for underground water-sealed propane storage caverns in Yantai was introduced and field tests of blasting vibration were carried out. Field test data showed that the horizontal radial velocity had a major controlling effect in the blasting vibration and frequencies would not cause the vibration velocity concentration effects. In terms of the influence of blasting vibration on adjacent caverns, the dynamic finite element model in LS-DYNA soft was established, whose reliability was verified by field test data. The numerical results indicated the near-blasting side was primary zone for the structural failure and tensile failure tended to occur in the middle of the curved wall on the near-blasting side. Meanwhile, the safety criterions for adjacent caverns based on stress wave theory and according to statistic relationship between peak effective tensile stress and peak particle velocities were obtained, respectively. Finally, with Safety Regulations for Blasting in China (GB6722-2014) taken into account, a final safety criterion was proposed.