• 제목/요약/키워드: pulse-like

검색결과 295건 처리시간 0.033초

교량의 지진취약도에 대한 속도 펄스를 가진 지반운동의 영향 (Effect of Velocity-Pulse-Like Ground Motions on Seismic Fragility of Bridges)

  • 김예은;꽁씨나;꽁씨닛;문지호;송종걸
    • 한국전산구조공학회논문집
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    • 제37권2호
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    • pp.119-131
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    • 2024
  • 일반적으로 속도 펄스를 가진 지반운동이 속도 펄스가 없는 지반운동에 비하여 구조물에 보다 큰 손상을 줄 수 있다고 알려져 있다. 지진가속도기록으로부터 속도 펄스의 유무의 판정과 이를 정량화하는 연구가 현재 많이 진행되어 오고 있다. 기존 지진기록들을 단층으로 떨어진 거리를 기준으로 원거리 지진과 근거리 지진으로 구분하였다. 또한, 근거리 지진은 속도 펄스의 유무를 정량화하여 펄스를 가진 지진과 펄스를 가지지 않은 지진으로 구분하였다. 최종적으로 각 지진그룹별로 40개의 원거리지진, 40개의 속도 펄스를 가진 근거리 지진과 40개의 속도 펄스를 가지지 않은 근거리 지진을 선정하였으며, 총 120개 지진가속도 기록을 지진취약도 평가를 위한 지진해석에 사용하였다. 세 그룹의 지진을 이용하여 납-고무받침과 탄성받침을 가진 두 종류의 예제교량에 대한 지진응답을 평가하여 확률론적 지진요구도 모델을 작성하였다. 확률론적 지진요구도 모델을 이용하여 지진취약도 해석을 수행하여 속도 펄스의 유무에 따른 지진취약도 영향을 분석하였다. 지진파의 속도 펄스 유무에 따른 지진취약도 곡선의 비교 결과로부터, 속도 펄스를 가진 지진의 지진취약도가 속도 펄스가 없는 지진의 지진취약도가 약 3배~5배 정도 정도 크게 나타난다. 이는 속도 펄스를 가진 지진의 경우가 그렇지 않은 지진의 경우에 비하여 교량의 손상 피해가 크다는 것을 의미한다.

Probabilistic behavior of semi-active isolated buildings under pulse-like earthquakes

  • Oncu-Davas, Seda;Alhan, Cenk
    • Smart Structures and Systems
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    • 제23권3호
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    • pp.227-242
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    • 2019
  • Seismic isolation systems employ structural control that protect both buildings and vibration-sensitive contents from destructive effects of earthquakes. Structural control is divided into three main groups: passive, active, and semi-active. Among them, semi-active isolation systems, which can reduce floor displacements and accelerations concurrently, has gained importance in recent years since they don't require large power or pose stability problems like active ones. However, their seismic performance may vary depending on the variations that may be observed in the mechanical properties of semi-active devices and/or seismic isolators. Uncertainties relating to isolators can arise from variations in geometry, boundary conditions, material behavior, or temperature, or aging whereas those relating to semi-active control devices can be due to thermal changes, inefficiencies in calibrations, manufacturing errors, etc. For a more realistic evaluation of the seismic behavior of semi-active isolated buildings, such uncertainties must be taken into account. Here, the probabilistic behavior of semi-active isolated buildings under historical pulse-like near-fault earthquakes is evaluated in terms of their performance in preserving structural integrity and protecting vibration-sensitive contents considering aforementioned uncertainties via Monte-Carlo simulations of 3-story and 9-story semi-active isolated benchmark buildings. The results are presented in the form of fragility curves and probability of failure profiles.

Use of near-fault pulse-energy for estimating critical structural responses

  • Chang, Zhiwang;Liu, Zhanhui;Chen, Zhenhua;Zhai, Changhai
    • Earthquakes and Structures
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    • 제16권4호
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    • pp.415-423
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    • 2019
  • Near-fault ground motions can impose particularly high seismic demands on structures due to the pulses that are typically observed in the velocity time-histories. In this study it is empirically found that the critical response can be estimated from the directions corresponding to the maximum (max) or minimum (min) pulse-energy. Determination of the pulse-energy requires removing of the high-frequency content. For achieving this, the wavelet analysis and the least-square-fitting (LSF) algorithm are adopted. Results obtained by the two strategies are compared and differences between them are analyzed. Finally, the relationship between the critical response and the response derived from directions having the max or min pulse-energy confirms that using the pulse-energy for deriving the critical response of the building structures is reasonable.

Suggestion for Objective Evaluation of Comparative Pulse Diagnosis

  • Jun-Sang Yu
    • 대한약침학회지
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    • 제27권1호
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    • pp.21-26
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    • 2024
  • Objectives: Pulse is a method of Korean medicine diagnosis and is an important clue to detect the organs, nature, and progress of the disease. Pulse examination is included in the basic examination of Korean medicine doctors, but there is no standardized method for diagnosing pulse although the types and methods of the pulse taking are briefly described in the literature, making it difficult to spread the examination method. In this regard, I would like to propose an objective evaluation method. Methods: Although the importance of pulse examination and the method of pulse examination are known in the literature, it is difficult for undergraduate students or inexperienced Korean medicine doctors to access it, so in this paper a method of marking the size of the pulse power in the blank space for objective evaluation was devised and presented. Results: The size of the pulse power should be indicated using the 1-cell, 3-cell, or 5-cell method according to the left and right wrists and the cun, guan and chi on both sides. Conclusion: The method of pulse diagnosis is an important diagnostic method as a verification process for making a Korean medical diagnosis. The remaining Korean medicine diagnostic methods, including pulse diagnosis, also need to undergo objectification. It is believed that the objectification of these diagnostic methods will lead to an improvement in the treatment rate of Korean medicine.

${\cdot}$ 침맥 진단에 유용한 맥상 파라메터 및 대표맥상 분석 (Analysing of pulse wave parameter and typical pulse pattern for diagnosis in floating and sinking pulses)

  • 이유정;이전;최은지;이혜정;김종열
    • 한국한의학연구원논문집
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    • 제12권2호통권17호
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    • pp.93-101
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    • 2006
  • Pulse feeling is one of the most important diagnosis method in Oriental medicine. But it is not easy to make an objective and standardized diagnosis. In this study, we found how to quantify diagnosis. Specially dally the high practicality in clinic, we search some parameters especially well-related to floating and sinking pulse by statistic analysis. By extension, we find the pulse patterns of the floating and sinking pulse. We choose 15 subjects diagnosed as floating pulse and 15 subjects diagnosed as sinking pulse by oriental doctors. And their pulse signals were acquired by Pulse analyzer which has piezoresistive pressure sensor. For the quantification of the floating and sinking pulse, at first, we examined the parameters which were highly correlated with oriental doctor's diagnosis. And then we derived pulse patterns of the floating-sinking pulse from preprocessed signal and its ensemble average. We also looked trend variation (PH-Curve) between contact and pulse pressure. As a result, statistically there is the biggest difference between contact pressure, the maximum pulse pressure, diastolic area (Ad) and floating and sinking data. Through the PH-Curve, which represented the relationship between contact and pulse pressure, we could divide the floating and sinking pulse clearly. As a basic research of pulse diagnosis algorithm, we can contribute to select essential parameters in diagnosis algorithm And using these diagnosis method, we expect to find typical pulse patterns and some useful parameters about other pulses like slow/rapid, large/fine pulse and so on. We hope that this study will contribute pulse objectification.

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Characterization and modeling of near-fault pulse-like strong ground motion via damage-based critical excitation method

  • Moustafa, Abbas;Takewaki, Izuru
    • Structural Engineering and Mechanics
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    • 제34권6호
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    • pp.755-778
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    • 2010
  • Near-fault ground motion with directivity or fling effects is significantly influenced by the rupture mechanism and substantially different from ordinary records. This class of ground motion has large amplitude and long period, exhibits unusual response spectra shapes, possesses high PGV/PGA and PGD/PGA ratios and is best characterized in the velocity and the displacement time-histories. Such ground motion is also characterized by its energy being contained in a single or very few pulses, thus capable of causing severe damage to the structures. This paper investigates the characteristics of near-fault pulse-like ground motions and their implications on the structural responses using new proposed measures, such as, the effective frequency range, the energy rate (in time and frequency domains) and the damage indices. The paper develops also simple mathematical expressions for modeling this class of ground motion and the associated structural responses, thus eliminating numerical integration of the equations of motion. An optimization technique is also developed by using energy concepts and damage indices for modeling this class of ground motion for inelastic structures at sites having limited earthquake data.

Partial Discharge Signal Denoising using Adaptive Translation Invariant Wavelet Transform-Online Measurement

  • Maheswari, R.V.;Subburaj, P.;Vigneshwaran, B.;Iruthayarajan, M. Willjuice
    • Journal of Electrical Engineering and Technology
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    • 제9권2호
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    • pp.695-706
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    • 2014
  • Partial discharge (PD) measurements have emerged as a dominant investigative tool for condition monitoring of insulation in high voltage equipment. But the major problem behind them the PD signal is severely polluted by several noises like White noise, Random noise, Discrete Spectral Interferences (DSI) and the challenge lies with removing these noise from the onsite PD data effectively which leads to preserving the signal for feature extraction. Accordingly the paper is mainly classified into two parts. In first part the PD signal is artificially simulated and mixed with white noise. In second part the PD is measured then it is subjected to the proposed denoising techniques namely Translation Invariant Wavelet Transform (TIWT). The proposed TIWT method remains the edge of the original signal efficiently. Additionally TIWT based denoising is used to suppress Pseudo Gibbs phenomenon. In this paper an attempt has been made to review the methodology of denoising the PD signals and shows that the proposed denoising method results are better when compared to other wavelet-based approaches like Fast Fourier Transform (FFT), Discrete Wavelet Transform (DWT), by evaluating five different parameters like, Signal to noise ratio, Cross-correlation coefficient, Pulse amplitude distortion, Mean square error, Reduction in noise level.

역대의가(歷代醫家)의 맥상(脈象) 분석(分類)에 대한 연구 (Study on Classification of Pulse Condition of the Chronological Medical Practitioners)

  • 박재원;김병수;강정수
    • 동의생리병리학회지
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    • 제22권6호
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    • pp.1347-1353
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    • 2008
  • Pulse condition is the essential division for conducting pulse diagnosis which is one of the most fundamental and important diagnostics in traditional Korean/Chinese medicine. We studied the pulse condition referred to classics of traditional medicine for a full understanding in present time and come to a conclusion like below. The reference to pulse condition was concluded to 'twenty four pulse conditions' which is the fundamental conception generally accepted in present age since it had first mentioned in "Huangdi Neijing" and after it had passed through "Nanjing", "pulse pattern identification-chapter of normal pulse"of Zhang Zhongjing and reached "Maijing"of Wang Shuhe. Although medical partitioners had different views to some extent about pulse condition, there were no significant differences in the main theoretical frame. Even though there had been a diversity of opinions on the classification of pulse-condition between various medical practitioners, the method of Dae-dae and the method of systematic endeavored by Zhou Xueting and Zhou Xuehai who were medical scholars in the Ch'ing dynasty have been a criterion for the classification of pulse-condition up to date. We were able to recognize that the change of pulse condition caused by pathological situation should be compared to physiological pulse condition for detecting the deficiency and excess by researching the analyzing methods of pulse condition mentioned in the "Lingshu", and the book of Hua Shou and Zhou Xuehai). To sum up, first normal pulse which is the physiological pulse condition should be a standard for detecting physiological pulse condition. Secondly, Zhou Xueting insisted that relaxed pulse should be a standard pulse condition for detecting normal pulse.

맥파자동진단을 위한 하드웨어의 설계 및 특성점 검출 알고리즘에 관한 연구 (A Study on the Significant Point Detection Algorithm and Design of Hardware for Pulse Automatic Diagnosis)

  • 이준영;이정환;이명호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 G
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    • pp.2255-2258
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    • 1998
  • Method of diagnosis in oriental medicine, the unbalance of the physiological function of the five viscers and six bowels of the human body is determined from time immemorial with the condition of blood circulation which is performed through blood vessels by the vitality of the heart. In oriental medicine, treatment is largely attempted by adjusting this unbalance. The analysis of pulse wave, which mainly measures the changes in blood flows, is to evaluate the shapes of a pulse wave rather than the quantitative changes like rates and strength of the pulse. This paper presents the development of Hardware System and Pulse Diagnosis Algorithm for automatic diagnosis of the pulse wave. This system makes the precise diagnosis and the objective recording possible.

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CMOS 소자에서 과도방사선펄스에 의한 Dose-Rate Latchup 모의실험 (Simulation for Dose-Rate Latchup by Transient Radiation Pulse in CMOS Device)

  • 이현진;이남호;황영관
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.1185-1186
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    • 2008
  • A nuclear explosion emits a transient radiation pulse like gamma rays. Gamma rays have a high energy and cause unexpected effects in semiconductor devices. These effects are mainly referred to dose-rate latcup and dose-rate upset. By transient radiation pulse in CMOS devices, dose-rate latchup is simulated in this paper.

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