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Time Series Analysis for Vibration-Based Structural Health Monitoring:A Review

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Structural Durability & Health Monitoring 2018年第3期12卷 129-147页

作者： Kong fah Tee School of Engineering University of GreenwichKentUK.

Structural health monitoring(SHM)is a vast,interdisciplinary research field whose literature spans several decades with focusing on condition assessment of different types of structures including aerospace,mechanical and civil *** need for quantitative global damage detection methods that can be applied to complex structures has led to vibration-based *** time series methods for SHM form an important and rapidly evolving category within the broader vibration-based *** the literature on the structural damage detection,many time series-based methods have been *** a considered time series model approximates the vibration response of a structure and model coefficients or residual error are obtained,any deviations in these coefficients or residual error can be inferred as an indication of a change or damage in the *** on the technique employed,various damage sensitive features have been proposed to capture the *** paper reviews the application of time series analysis for *** different types of time series analysis are described,and the basic principles are explained in ***,the literature is reviewed based on how a damage sensitive feature is *** addition,some investigations that have attempted to modify and/or combine time series analysis with other approaches for better damage identification are presented.

关键词： Time series snalysis structural health monitoring structural damage detection autoregressive model damage sensitive features

Extraction of real modes and physical matrices from modal testing

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Earthquake Engineering and Engineering Vibration 2011年第2期10卷 219-227页

作者： Wang Tong Zhang Lingmi Tee Kong fah MOE Key Lab of Structural Mechanics and Control for Aircraft Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Department of Civil Engineering University of Greenwich United Kingdom

A technique to extract real modes from the identified complex modes is presented in this paper, which enables the normalized real mode shapes, modal masses, and full or reduced mass and stiffness matrices to be obtained. The theoretical derivation of the method is provided in detail. An 11-DOF vibration system is used to validate the algorithm, and to analyze the effects of the number of modes utilized and measurement DOFs on the extraction results. Finally, the method is used to extract real modes from both experimental modal analysis and operational modal analysis.

关键词： modal analysis complex mode real mode normalized mode shape modal mass

Comparison of Structural Probabilistic and Non-Probabilistic Reliability Computational Methods under Big Data Condition

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Structural Durability & Health Monitoring 2022年第2期16卷 129-143页

作者： Yongfeng Fang Kong fah Tee School of Physics and Electronic Information Engineering Ningxia Normal UniversityGuyuan756000China School of Engineering University of GreenwichKentME44TBUK School of Mechanical Engineering Guizhou University of Engineering ScienceBijie551700China

In this article,structural probabilistic and non-probabilistic reliability have been evaluated and compared under big data ***,the big data is collected via structural monitoring and *** data is classified into different types according to the regularities of the distribution of *** different stresses which have been subjected by the structure are used in this ***,the structural interval reliability and probabilistic pre-diction models are established by using the stress-strength interference theory under big data of random loads after the stresses and structural strength are comprehensively *** reliability is computed by using various stress types,and the minimum reliability is determined as structural ***,the advan-tage and disadvantage of the interval reliability method and probability reliability method are shown by using three *** has been shown that the proposed methods are feasible and effective.

关键词： Big data structure interval reliability probabilistic reliability reliability index

Finite Element Model Updating for Structural Health Monitoring

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Structural Durability & Health Monitoring 2020年第1期14卷 1-17页

作者： Amirabbas Haidarpour Kong fah Tee School of Engineering University of GreenwichChatham MaritimeKentME44TBUK

This paper provides a model updating approach to detect,locate,and char-acterize damage in structural and mechanical systems by examining changes in mea-sured vibration *** in vibration-based damage identification has been rapidly expanding over the last few *** basic idea behind this technology is that modal parameters(notably frequencies,mode shapes,and modal damping)are functions of the physical properties of the structure(mass,damping,and sifies).Therefore,changes in the physical properties will cause changes in the modal proper-ties which could be obtained by structural health monitoring(SHM).Updating is a process fraught with numerical *** arise from inaccuracy in the model and imprecision and lack of information in the measurements,mainly taken place in joints and critical *** motivation for the development of this technology ***,methods are categorized according to various criteria such as the level of damage detection provided from vibration testing,natural frequency and mode shape readings are then obtained by using modal analysis techniques,which are used for updating structural parameters of the associated finite element model The experi-mental studies for the laboratory tested bridge model show that the proposed *** using ME scope technique can provide reasonable model updating results.

关键词： Structural health monitoring model updating natural frequency mode shape stiffness vibration testing

Implementation of a real-time, data-driven online Epidemic Calculator for tracking the spread of COVID-19 in Singapore and other countries

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Infectious Disease Modelling 2021年第1期6卷 1159-1172页

作者： Fook fah Yap Minglee Yong Nanyang Technological University School of Mechanical and Aerospace Engineering50 Nanyang AveSingapore639798Singapore Nanyang Technological University National Institute of Education1 Nanyang WalkSingapore637616Singapore

While there are many online data dashboards on COVID-19,there are few analytics available to the public and non-epidemiologists to help them gain a deeper insight into the COVID-19 pandemic and evaluate the effectiveness of social intervention *** address the issue,this study describes the methods underlying the development of a realtime,data-driven online Epidemic Calculator for tracking COVID-19 growth *** publicly available infection case and death data,the calculator is used to estimate the effective reproduction number,final epidemic size,and death *** a case study,we analyzed the results for Singapore during the"Circuit Breaker"period from April 7,2020 to the end of May *** calculator shows that the stringent measures imposed have an immediate effect of rapidly slowing down the spread of the *** about two weeks,the effective reproduction number reduced to about *** then,the number has been fluctuating around 1.0 for more than a *** COVID-19 Epidemic Calculator is available in the form of an online Google Sheet and the results are presented as Tableau Public dashboards at *** making the calculator readily accessible online,the public can have a tool to assess the effectiveness of measures to control the pandemic meaningfully.

关键词： COVID-19 Reproduction number Doubling time Epidemic calculator Singapore

Industry-and liquidity-based momentum in Australian equities

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Financial Innovation 2019年第1期5卷 740-757页

作者： Yeng May Tan Fan fah Cheng School of Economics and Management Xiamen University MalaysiaJalan SunsuriaBandar Sunsuria43900 SepangSelangorMalaysia Department of Accounting and Finance Faculty of Economics and ManagementUniversiti Putra MalaysiaJalan Upm43400 SerdangSelangorMalaysia

This study examined momentum profitability in Australia,providing further evidence for intermediate-term momentum *** data spanning different market states,we found that momentum was stronger after the global financial *** also examined industry-level momentum strategies and found strong evidence for industry ***,industries that perform well relative to other industries continue to outperform others while those that underperform continue to perform *** finding suggests the exploitability of return continuation and profit-making opportunities for traders at the industry *** liquidity,we found that it has no clear predictive power for momentum ***,our results do not appear to support the conjecture that liquidity can be a determining factor for momentum profitability in Australia.

关键词： Momentum strategy Stock momentum Industry momentum Liquidity Market states Australia

Cavernous hemangioma arising from the gastro-splenic ligament: A case report

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World Journal of Gastroenterology 2009年第30期15卷 3831-3833页

作者： Kin-fah Chin Ghaith Khair Palani Sathish Babu David Russell Morgan Department of Surgery University of Malaya50603 Kuala LumpurMalaysia Department of Surgery Scarborough HospitalScarborough YO12 6QLUnited Kingdom Department of Gastroenterology Scarborough HospitalScarborough YO12 6QLUnited Kingdom Department of Pathology Scarborough HospitalScarborough YO12 6QLUnited Kingdom

We present a rare case of a 45-year-old woman who presented with epigastric pain associated with early satiety and weight loss. Imaging revealed a large intraabdominal mass in the epigastrium. Despite intensive investigations, including ultrasound scanning, computed tomography, upper gastrointestinal endoscopy, and percutaneous biopsy, a diagnosis could not be obtained. A histological diagnosis of cavernous hemangioma arising from the gastro-splenic ligament was confirmed after laparoscopic excision and histological examination of the intra-abdominal epigastric mass.

关键词： Hemangioma Laparoscopy Abdominalneoplasms Vascular diseases Gastrointestinal neoplasms

Bacterial microbiome of Coptotermes curvignathus （Isoptera： Rhinotermitidae） reflects the coevolution of species and dietary pattern

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Insect Science 2014年第5期21卷 584-596页

作者： Jie Hung Patricia King Nor Muhammad Mahadi Choon fah Joseph Bong Kian Huat Ong Osman Hassan Faculty of Agriculture and Food Sciences Universiti Putra Malaysia Bintulu Sarawak Campus Sarawak Malaysia Genome Institute Jalan Bangi Lama 43000 Kajang Faculty of Science and Technology UniversiU Kebangsaan Malaysia 43600 UKM BangiSelangor Malaysia

Coptotermes curvignathus Holmgren is capable of feeding on living trees. This ability is attributed to their effective digestive system that is furnished by the termite＇s own cellulolytic enzymes and cooperative enzymes produced by their gut microbes. In this study, the identity of an array of diverse microbes residing in the gut of C. curvignathus was revealed by sequencing the near-full-length 16S rRNA genes. A total of 154 bacterial phylotypes were found. The Bacteroidetes was the most abundant phylum and accounted for about 65% of the gut microbial profile. This is followed by Firmicutes, Actinobacteria, Spirochetes, Proteobacteria, TM7, Deferribacteres, Planctomycetes, Ferrucomicrobia, and Termite Group 1. Based on the phylogenetic study, this symbiosis can be a result of long coevolution of gut enterotypes with the phylogenic distribution, strong selection pressure in the gut, and other speculative pressures that determine bacterial biome to follow. The phylogenetic distribution of cloned rRNA genes in the bacterial domain that was considerably different from other termite reflects the strong selection pressures in the gut where a proportional composition of gut microbiome of C. curvignathus has established. The selection pressures could be linked to the unique diet preference of C. curvignathus that profoundly feeds on living trees. The delicate gut microbiome composition may provide available nutrients to the host as well as potential protection against opportunistic pathogen.

关键词： Coptotermes curvignathus diet preference gut microbiome selection

Effect of long-acting testosterone undecanoate treatment on quality of life in men with testosterone deficiency syndrome： a double blind randomized controlled trial

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Asian Journal of Andrology 2012年第4期14卷 604-611页

作者： Seng-fah Tong Chirk-Jenn Ng Boon-Cheok Lee Verna-KM Lee Ee-Ming Khoo Eng-Giap Lee Hui-Meng Tan Universiti Kebangsaan Malaysia Kuala Lumpur 56000Malaysia University of Malaya Lumpur 56000Malaysia Sime Darby Medical Centre Selangor 47500Malaysia International Medical University Kuala Lumpur 57000Malaysia

This study aimed to investigate the effect of intramuscular injection of testosterone undecanoate on overall quality of life （QoL） in men with testosterone deficiency syndrome （TDS）. A randomized controlled trial over a 12-month period was carried out in 2009. One hundred and twenty men aged 40 years and above with a diagnosis of TDS （serum total testosterone 〈12 nmol 1-1 and total Aging Male Symptom （AMS） scores ≥ 27） were invited to participate. Interventions comprised intramuscular injection of either placebo or 1000 mg testosterone undecanoate, given at weeks O, 6, 18, 30 and 42. This paper presents the secondary analysis of QoL changes measured in the scores of Short-Form-12 （SF-12） scale at baseline, weeks 30 and 48 after the first injection. A total of 56/60 and 58/60 men from the active treatment and placebo group, respectively, completed the study. At week 48, before adjusting for baseline differences, the QoL of men in the treatment group improved significantly in five out of the eight domains on SF-12. The physical health composite scores improved 4.0 points from a baseline of 41.9±7.0 in the treatment group compared to 0.8 point from a baseline of 43.7--7.1 in the placebo group （F=3.652, P=0.027）. The mental health composite scores improved 4.4 points from a baseline of 37.1±9.0 in the treatment group compared to 1.0 points from a baseline of 37.6±7.9 in the placebo group （F=4.514, P=-0.018）. After adjusting for baseline differences, significant improvement was observed in mental health composite scores, but not in physical health composite scores. LQng-acting testosterone undecanoate significanUy improved the mental health component of QoL in men with TDS.

关键词： hypogonadism randomized controlled trial quality of life testosterone deficiency syndrome (TDS) testosterone therapy