• Title/Summary/Keyword: structural diagnosis

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A Study on the Improvement of Evaluation Method of Diagnosis-System for Exterior-Wall Deterioration by Infrared Thermography (적외선 탐사기를 이용한 외벽열화 진단시스템의 평가기법 향상에 관한 연구)

  • Kim, Moo-Han;Kwon, Young-Jin;Kang, Suk-Puo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.2
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    • pp.185-190
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    • 1999
  • It is difficult to estimate for deterioration of exterior wall by infrared thermography, because of amount of infrared-ray radiation effected by environmental factors such as temperature properties of materials, the outside air and the amount of solar radiation. Therefore we measured the distribution of temperature by times in the same reinforced-concrete structure in order to reduce problems, occasioned by environmental factors, then we analyzed physical influence factors of the infrared thermography. It is the aim of this study to suggest basic data with regard to method of estimation-system for deterioration of exterior wall in reinforced-concrete structures.

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On the development of data-based damage diagnosis algorithms for structural health monitoring

  • Kiremidjian, Anne S.
    • Smart Structures and Systems
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    • v.30 no.3
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    • pp.263-271
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    • 2022
  • In this paper we present an overview of damage diagnosis algorithms that have been developed over the past two decades using vibration signals obtained from structures. Then, the paper focuses primarily on algorithms that can be used following an extreme event such as a large earthquake to identify structural damage for responding in a timely manner. The algorithms presented in the paper use measurements obtained from accelerometers and gyroscope to identify the occurrence of damage and classify the damage. Example algorithms are presented include those based on autoregressive moving average (ARMA), wavelet energies from wavelet transform and rotation models. The algorithms are illustrated through application of data from test structures such as the ASCE Benchmark structure and laboratory tests of scaled bridge columns and steel frames. The paper concludes by identifying needs for research and development in order for such algorithms to become viable in practice.

Ambient vibration tests of XV century Renaissance Palace after 2012 Emilia earthquake in Northern Italy

  • Cimellaro, Gian Paolo;De Stefano, Alessandro
    • Structural Monitoring and Maintenance
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    • v.1 no.2
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    • pp.231-247
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    • 2014
  • This paper focuses on the dynamic behaviour of Mirandola City Hall (a XV century Renaissance Palace) that was severely damaged during May 2012 Emilia earthquake in Northern Italy. Experimental investigations have been carried out on this monumental building. Firstly, detailed investigations have been carried out to identify the identification of the geometry of the main constructional parts as well as the mechanical features of the constituting materials of the palace. Then, Ambient Vibration Tests (AVT) have been applied, for the detection of the main dynamic features. Three output-only identification methods have been compared: (i) the Frequency Domain Decomposition, (ii) the Random Decrement (RD) and the (iii) Eigensystem Realization Algorithm (ERA). The modal parameters of the Palace were difficult to be identified due to the severe structural damage; however the two bending modes in the perpendicular directions were identified. The comparison of the three experimental techniques showed a good agreement confirming the reliability of the three identification methods.

An Experimental Study on the Strength Evaluation of existing Structural Members for the Remodelling Construction of Apartments Housing (공동주택의 리모델링을 위한 기존부재의 내력평가 실험연구)

  • Shin, Hyun-Seop;You, Young-Chan;Lim, Byung-Ho;Choi, Ki-Sun;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.29-32
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    • 2006
  • Different from new or reconstruction of an apartment housing, the structural safety in the remodelling construction can be obtained through the repair and strengthening process based on the safety diagnosis and evaluation of structural performance. In this study, structural performance of existing members such as, reinforced concrete slabs, beams and columns are investigated through experimental tests. The structural members were obtained from the existing apartment housing which will be demolished. Test results showed that most specimens have a sufficient structural capacity except for some special case, for example, specimens with severe cracks or concrete loss due to improper casting. This same severe deteriorated or defective structure members originated from bad concrete casting or careless construction process should be repaired and strengthened before an remodelling construction.

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Development and Evaluation of Ontology for Diagnosis in Oriental Medicine (한의진단 Ontology 구축과 평가)

  • Shin Sang-Woo;Jung Gil-San;Park Kyung-Mo;Kim Seon-Ho;Park Jong-Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.1
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    • pp.202-208
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    • 2006
  • The goal of this study is to develop knowledge representation method for the construction and evaluation of ontology for diagnosis in oriental medicine. To develop the expert system for decision making on diagnosis and treatment, the systematic and structural knowledge which can be processible in EMR(Electronic Medical Record) must be precedent, and the Computational Process which control the system as well. This study set up an ontology as a trial model to represent the oriental medical knowledge into the machine processible one. Protege 2.1 has been used to build the ontology, and the serialization format of our ontology is the XML document based on OWL. The components of oriental medical diagnosis was arranged with the combination of symptoms which belong to the certain symptom patterns. Then natural language which expresses the oriental medical diagnosis components were converted into the logical sentence, and individual characteristic symptoms into each values of specific properties. In addition to the study, the diagnosis software for oriental medicine was developed and it used the ontology which we developed. Sequently, we tested the software to confirm the appropriateness of ontology. The result of the test shows that diagnostic questions are automatically formulated according to the diagnosis components of this ontology and that as such diagnostic results are induced. Therefore, the ontology system in this study will be efficient to develop the diagnosis program and useful as a tool for doctors to make decision. But, it is not recommendable to apply the system to the clinical environment until the clear diagnosis standards are introduced, and the more reliable diagnosis program can be developed based on the more appropriate ontology mentioned above.

Analysis of sEMG Median frequency and Ultrasound Image Echodensity of Normal Skeletal Muscle (정상 골격근의 근전도 중앙주파수 및 초음파 영상 밀도 분석)

  • Jeong, Jin-Gyu;Kim, Yong-Nam;Hwang, Tae-Yeun;Lee, Jeong-Woo;Kim, Tae-Youl
    • The Journal of Korean Physical Therapy
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    • v.18 no.1
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    • pp.83-94
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    • 2006
  • Purpose: This study conducts quantitative evaluation or structural and functional characteristics or normal skeletal muscle with ultrasound image and surface electromyography, and is to provide basic materials for utilizing ultrasound image analysis in physical therapy diagnosis and assessment of skeletal muscle. Methods: Measurement of three stages was conducted with 88 normal adults between their twenties and seventies, correlations and differences using collected data according to age and gender were compared and correlations among measured items were analyzed and then the following conclusions were obtained. Results: Analysis of ultrasound image of normal skeletal muscle showed that density, median frequency had the closest relations with age. In addition, it was found that there were high correlations between density explaining structural characteristics of skeletal muscle and median frequency explaining functional characteristics. Conclusion: Analysis of ultrasound image makes complex evaluation of structure and function of skeletal muscle possible when it is connected with functional evaluation method using physical measurement surface electromyography as well as quantitative evaluation of structural changes of skeletal muscle and is effective in complementing physical therapy diagnosis centering around functionality evaluation.

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Design of Digital Systems for Web -based Pulse Diagnosis Database

  • Lee, Junyoung;Lee, Sungjae;Lee, Myoungho;Kim, Jeonghoon
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.181.4-181
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    • 2001
  • In this study, we have developed the digital hardware system which performs signal processing necessary for the filtering to eliminate noises by inputting pulse wave signals from the sensor group. With a view to obtain clinically effective information, we analyzed structural elements of pulse waveform and, thus, conducted a systematic classification. What is more, this study has conducted researches in the web-based diagnosis data management system of pulse waveform as well as the method of transmitting the data of pulse waveform. In order to set the standard for the documents of the pulse ...

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Fault Tolerant Control Design Using IMM Filter with an Application to a Flight Control System (IMM 필터를 이용한 고장허용 제어기법 및 비행 제어시스템에의 응용)

  • 김주호;황태현;최재원
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.87-87
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    • 2000
  • In this paper, an integrated design of fault detection, diagnosis and reconfigurable control tot multi-input and multi-output system is proposed. It is based on the interacting multiple model estimation algorithm, which is one of the most cost-effective adaptive estimation techniques for systems involving structural and/or parametric changes. This research focuses on the method to recover the performance of a system with failed actuators by switching plant models and controllers appropriately. The proposed scheme is applied to a fault tolerant control design for flight control system.

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Study of the structural damage identification method based on multi-mode information fusion

  • Liu, Tao;Li, AiQun;Ding, YouLiang;Zhao, DaLiang
    • Structural Engineering and Mechanics
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    • v.31 no.3
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    • pp.333-347
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    • 2009
  • Due to structural complicacy, structural health monitoring for civil engineering needs more accurate and effectual methods of damage identification. This study aims to import multi-source information fusion (MSIF) into structural damage diagnosis to improve the validity of damage detection. Firstly, the essential theory and applied mathematic methods of MSIF are introduced. And then, the structural damage identification method based on multi-mode information fusion is put forward. Later, on the basis of a numerical simulation of a concrete continuous box beam bridge, it is obviously indicated that the improved modal strain energy method based on multi-mode information fusion has nicer sensitivity to structural initial damage and favorable robusticity to noise. Compared with the classical modal strain energy method, this damage identification method needs much less modal information to detect structural initial damage. When the noise intensity is less than or equal to 10%, this method can identify structural initial damage well and truly. In a word, this structural damage identification method based on multi-mode information fusion has better effects of structural damage identification and good practicability to actual structures.