• Title/Summary/Keyword: statistical assessment

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Structural Damage Detection Based on Composite Data of Static and Modal Test (정적변위와 진동모우드 특성치의 합성자료를 이용한 구조물의 손상도 추정)

  • 정범석;한종석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.147-155
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    • 1996
  • The purpose of present study is to propose a improved damage detection and assessment algorithm that has its basis on the method of system identification. In this approach, the complete sets of modes or displacements are not needed since the error response function involves only the difference between components of those vectors. The present approach also allows the use of composite data which is constitute of static displacements and eigenmodes. The effectiveness of the proposed statistical system identification method is investigated through simulated studies. A series of tests for predetermined damaged cantilever beam and bowstring truss structure have been conducted to verify the proposed method.

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Probabilistic Integrity Assessment of CANDU Pressure Tube for the Consideration of Flaw Generation Time (결함발생 시점을 고려한 CANDU 압력관 결함의 확률론적 건전성평가)

  • Kwak, Sang-Log;Lee, Joon-Seong;Kim, Young-Jin;Park, Youn-Won
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.155-160
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    • 2001
  • This paper describes a probabilistic fracture mechanics (PFM) analysis based on Monte Carlo (MC) simulation. In the analysis of CANDU pressure tube, it is necessary to perform the PFM analyses based on statistical consideration of flaw generation time. A depth and an aspect ratio of initial semi-elliptical surface crack, a fracture toughness value, delayed hydride cracking (DHC) velocity, and flaw generation time are assumed to be probabilistic variables. In all the analyses, degradation of fracture toughness due to neutron irradiation is considered. Also, the failure criteria considered are plastic collapse, unstable fracture and crack penetration. For the crack growth by DHC, the failure probability was evaluated in due consideration of flaw generation time.

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Method of Estimate of Fracture Probability for Elastic-Plasticity by 2-Parameter Criterion (2-parameter criterion에 의한 탄소성 파괴확률 예측수법)

  • Kim, Tae-Sik;Yoon, Han-Yong;Lim, Myung-Hwan;Chung, Ui-Chung
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.226-234
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    • 2003
  • Put Many researcher have made much progress in studying an estimate for fracture probability of brittle materials. However, studies of the fracture probability for the elastic-plasticity have not been made yet. An estimate method for fracture probability which is grafted onto 2-parameter criterion and statistical probability analysis is not only introduced in this study, but also applied to the simple 2dimensional model and carbon steel piping to evaluate the effect of random variable.

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Evaluation and analytical approximation of Tuned Mass Damper performance in an earthquake environment

  • Tributsch, Alexander;Adam, Christoph
    • Smart Structures and Systems
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    • v.10 no.2
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    • pp.155-179
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    • 2012
  • This paper aims at assessing the seismic performance of Tuned Mass Dampers (TMDs) based on sets of recorded ground motions. For the simplest configuration of a structure-TMD assembly, in a comprehensive study characteristic response quantities are derived and statistically evaluated. Optimal tuning of TMD parameters is discussed and evaluated. The response reduction by application of a TMD is quantified depending on the structural period, inherent damping of the stand-alone structure, and ratio of TMD mass to structural mass. The effect of detuning on the stroke of the TMD and on the structural response is assessed and quantified. It is verified that a TMD damping coefficient larger than the optimal one reduces the peak deflection of the TMD spring significantly, whereas the response reduction of the main structure remains almost unaffected. Analytical relations for quantifying the effect of a TMD are derived and subsequently evaluated. These relations allow the engineer in practice a fast and yet accurate assessment of the TMD performance.

On the Recovery from Error Based on Aging (Error 회복 중심의 Aging)

  • Lee, Keun-Boo
    • Journal of the Korea Safety Management & Science
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    • v.11 no.2
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    • pp.159-165
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    • 2009
  • Through the understanding of the change of productivity and the ability of error recovery according to aging and the assessment and analysis of them, we may take this research to contribute to make a design for the road-map to help set up the policy of employment for old generation. For this we have taken an experiment of the coordination tester for 100 person who are chosen randomly and analysed the collected data using SAS, which is one of widely used statistical analysis packages. The main results are as follow: $\circledcirc$ The result of regression between the working speed and the length of the correction of error shows independence. (pr>0.2029). $\circledcirc$ The regression between age and working speed is statistically significant. (pr<0.0001) $\circledcirc$ The relation between age and the length of the correction of error is not significant. (pr>0.9123).

Numerical Verification of the Proposed Design Procedure of MR Damper for Seismic Response Control of Building Structure (건축 구조물의 지진응답 제어를 위해 제안된 MR감쇠기 설계 절차의 수치적 검증)

  • Lee, Sang-Hyun;Min, Kyung-Won;Lee, Roo-Jee
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.521-528
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    • 2005
  • In our previous study, we have developed a preliminary design procedure of MR dampers for controlling seismic response of building structures. In this paper, the effectiveness the proposed method is verified through the numerical analysis of the structures with various period and story number, and twenty earthquake loads are used for statistical assessment. The comparison between the proposed method and simplified sequential search algorithm indicates that the capacity, number and the placement of the MR damper which can achieve the given performance objective are reasonably determined using the proposed design procedure.

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Metabolomics Approach for Classification of Medicinal Plants

  • Lee, Dong-Ho
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2010.05a
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    • pp.5-5
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    • 2010
  • Selection of specific medicinal sources as well as bioactive compounds is important for the preparation of medicine and related products with good quality. It is necessary to pay close attention for choosing correct medicinal sources, particularly in case of medicinal plants, because of their diversity, which can affect the quality and efficacy of medicine. Discrimination of plants based on morphological or genetic characteristics has been used as a conventional classification method of pharmaceutical sources so far; however, more need demands more general methods for accurate quality assessment of medicinal plants. In this study, ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) technique applied to this metabolic profiling is a powerful tool due to its higher sensitivity, resolution, and speed compared to conventional HPLC technique. The metabolite profiling of several medicinal plants including Panax ginseng was carried out using UPLC/Q-TOF MS and total metabolites were then subsequently applied to various statistical tools to compare the patterns. The developed metabolomics tool with UPLC/Q-TOF MS successfully identified and classified the samples tested according to their origins.

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Suggest on Standardization of Ecological Survey Methods in the Korean Watershed (한국연안에서의 해양생물 생태 조사방법 표준화)

  • 이재학
    • Korean Journal of Environmental Biology
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    • v.22 no.1
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    • pp.1-11
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    • 2004
  • Ecological methods were reviewed through reports such as environmental impact assessment and damage effect of fishery in the Korean watershed. Survey items in marine ecological field were included: phytoplankton, zooplankton, benthic animal, algae, adult fish, egg and juvenile of fish. A standardization of survey method in the field of community ecology was suggested to consider the convenience, Sequency in Use of device, accuracy of data collected from that. It is necessary that spatial data should be sufficiently acquired toy statistical analysis of biodiversity and spatial comparison. Quantitative sampling method must be inevitably adopted based nature of biota and geographical type of the survey area. The same sampling method can make the data compared spatially but can't be applicable in all area. Standardizing survey method should be by no means under certain restriction of study and would become different according to survey environments. The first thing is minutely understanding about ecological character of biota inhabiting in certain area, and then determining survey method.

A Study on the Assessment Method of Noise Exposure Population Using the Over-ride Value Noise Map (Over-ride Value 소음지도를 이용한 소음노출인구 산정방법 연구)

  • Park, In-Sun;Park, Sang-Kyu
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.7 s.100
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    • pp.859-864
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    • 2005
  • Noise map is a presentation of existing data or predicted noise situation in terms of noise indicator. However, it has shortcoming for assessing the number of people exposed, or the number of dwellings affected to any relevant limit values of noise level in certain areas. In this study, so called over-ride value noise mapping is Proposed to make up for the shortcoming by using over-ride function of object-oriented programming and it is to show the guard of the area where it is satisfied the standard of option, or it is not satisfactory. Over-ride value noise map data is combined with topography layer, population and house statistics, and GIS space statistical analysis. The over-ride value noise mapping can also be applied to make the road traffic noise map, the railroad noise map, the aircraft noise map, and the industrial site noise map. This can express noise damage information more exactly.

Design and Evaluation of Digital Inclinometer for Measuring Postural Balance (자세 균형 측정을 위한 디지털 경사계 설계 및 평가)

  • Myoung, Hyoun-Seok;Lee, Hyo-Ki;Lee, Kyoung-Joung;Kwon, Oh-Yun
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.64-66
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    • 2007
  • In this paper, a digital inclinometer to measure the angle and acceleration signals of subject laid on Roll was designed. The designed system consists of a tilt sensor, biaxial accelerometer, microcontroller and BlueTooth module. The designed digital inclinometer was easy to handle and easy to wear. To evaluate the performance of the system, we measured simultaneously the angle and acceleration signals from the 3 subjects on the Roll with two instruments which are ZEBRIS and our system. The measured signals were processed by statistical method and then the correlation coefficient of 0.93 was shown. From the results, the designed digital inclinometer is shown to be useful in assessment of body movement.

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