A case study of damage detection in four-bays steel structures using the HHT approach

Wen-Ko Hsu,Cheng-Wu Chen,Dung-Jiang Chiou,Ming-Yi Liu,Wei-Ling Chiang,Pei-Chiung Huang 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.14 No.4

This study aims to investigate the relationship between structural damage and sensitivity indices using the Hilbert-Huang transform (HHT) method. Two damage detection indices are proposed: the ratio of bandwidth (RB), and the ratio of effective stiffness (RES). The nonlinear four bays multiple degree of freedom models with various predominant frequencies are constructed using the SAP2000 program. Adjusted PGA earthquake data (Japan 311, Chi-Chi 921) are used as the excitations. Next, the damage detection indices obtained using the HHT and the fast Fourier transform (FFT) methods are evaluated based on the acceleration responses of the structures to earthquakes. Simulation results indicate that, the column of the 1st floor is the first yielding position and the RB value is changed when the RES<90% in all cases. Moreover, the RB value of the 1st floor changes more sensitive than those from the top floor. In addition, when the structural response is nonlinear (i.e., RES<100%), the RB and the RES curves indicate the incremental change in the HHT spectra. However, the same phenomenon can be found from FFT spectra only when the stiffness reduction is large enough. Therefore, the RB estimated from the smoothed HHT spectra is an effective and sensitive index for detecting structural damage.

A case study of damage detection in four-bays steel structures using the HHT approach

Hsu, Wen-Ko,Chiou, Dung-Jiang,Chen, Cheng-Wu,Liu, Ming-Yi,Chiang, Wei-Ling,Huang, Pei-Chiung Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.14 No.4

This study aims to investigate the relationship between structural damage and sensitivity indices using the Hilbert-Huang transform (HHT) method. Two damage detection indices are proposed: the ratio of bandwidth (RB), and the ratio of effective stiffness (RES). The nonlinear four bays multiple degree of freedom models with various predominant frequencies are constructed using the SAP2000 program. Adjusted PGA earthquake data (Japan 311, Chi-Chi 921) are used as the excitations. Next the damage detection indices obtained using the HHT and the fast Fourier transform (FFT) methods are evaluated based on the acceleration responses of the structures to earthquakes. Simulation results indicate that, the column of the 1 st floor is the first yielding position and the RB value is changed when the RES<90% in all cases. Moreover, the RB value of the 1 st floor changes more sensitive than those from the top floor. In addition, when the structural response is nonlinear (i.e., RES<100%), the RB and the RES curves indicate the incremental change in the HHT spectra. However, the same phenomenon can be found from FFT spectra only when the stiffness reduction is large enough. Therefore, the RB estimated from the smoothed HHT spectra is an effective and sensitive index for detecting structural damage.

Apply the combination of anthropometric health indicators and Sheldon`s somatotype in health promotion

Wen-Ko Chiou,Ming-Hsu Wang,Bi-Hui Chen 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

The concept of somatotyping is a unique method for the classification of human physique that was first invented by Sheldon and modified by Heath and Carter. Somatotype is also widely used as a tool to estimate the nutritional status of populations and to monitor the growth and diseases of individuals. Human bodies compose from many parts and it is difficult to judge the healthy status from the single index. The body image compose form the multiple indexes could help people to judge the healthy status from the anthropometry data. The aim of this study was to develop body image templates in both genders from the 3D anthropometry data to evaluate the human healthy status. This study collected the dimensions from anthropometry and body image among 90 Taiwanese participants in the Keelung Chang Gung Memorial Hospital, Taiwan. This research uses the 3D whole body photography system to collect the anthropometry dimensions and analyze the data from the Beauty3D software. Collecting the 5 indexes, including body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), waist-height ratio (WHtR) and waist-thigh ratio (WTR) and to judge the indexes for normal and abnormal status by the WHO standards. Using the multiple indexes to category the body health into 4 levels. The results show that 4 body image templates in both genders were created, and the difference between the different templates and genders were discovered. The body image templates showed the human body images come from the different health status. It can be concluded that different body image templates from the multiple dimensions can lead to judge the human healthy status and base on the different templates could provide the visual judgment for the different body types for the health status.

Apply the Combination of Anthropometric Health Indicators and Sheldon`s Somatotype in Health Promotion

( Wen Ko Chiou ),( Ming Hsu Wang ),( Bi Hui Chen ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

The concept of somatotyping is a unique method for the classification of human physique that was first invented by Sheldon and modified by Heath and Carter. Somatotype is also widely used as a tool to estimate the nutritional status of populations and to monitor the growth and diseases of individuals. Human bodies compose from many parts and it is difficult to judge the healthy status from the single index. The body image compose form the multiple indexes could help people to judge the healthy status from the anthropometry data. The aim of this study was to develop body image templates in both genders from the 3D anthropometry data to evaluate the human healthy status. This study collected the dimensions from anthropometry and body image among 90 Taiwanese participants in the Keelung Chang Gung Memorial Hospital, Taiwan. This research uses the 3D whole body photography system to collect the anthropometry dimensions and analyze the data from the Beauty3D software. Collecting the 5 indexes, including body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), waist-height ratio (WHtR) and waist-thigh ratio (WTR) and to judge the indexes for normal and abnormal status by the WHO standards.

Height effect could be a factor for the musculoskeletal disorder in cleaning occupation

Ming-Hsu Wang,Wen-Ko Chiou,Bi-Hui Chen 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

Clearly, cleaning is a demanding repetitive occupation, which incurs a high level of musculoskeletal disorders. The phrase “work-related upper limb musculoskeletal disorders” includes a variety of upper limb degenerative and inflammatory diseases and disorders, which result in pain and functional impairment. Inappropriate and poor working postures, lack of task variation, poor ergonomic design of work places, poor design of cleaning tools and work organization (e.g., long working hours, low salaries and awkward schedules) are all areas where relatively simple interventions can significantly reduce the rate of exposure to occupational disease. The poor working resources make the high rate of related musculoskeletal disorders for the cleaners. The aim of this study was to compare the musculoskeletal disorders with different height of the cleaners and to evaluate the effect of height on cleaners’ working postures in a school environment. Thirty motivated professional female cleaners from one university in Taiwan took part in this survey. Their age ranged from 45 to 65 years and the average length of their work experience was 6.5 years. The survey was carried out according to the following steps: Step 1: Definition of the framework/theme of the survey. Step2: Establishment of the goal, Step3: Nordic Musculoskeletal Questionnaire (NMQ) survey, Step4: Development of a cleaning task analysis, Step5: Rapid Entire Body Assessment (REBA) survey, Step6: Evaluation for NMQ and REBA. Base on this research result, it can be concluded that different heights with the cleaners can lead to different musculoskeletal disorders and base on the different heights could provide the different protection devices and recommendations which, in turn, leads to the cleaners’ better health and better cleaning results.

Height Effect could be a Factor for the Musculoskeletal Disorder in Cleaning Occupation

( Ming Hsu Wang ),( Wen Ko Chiou ),( Bi Hui Chen ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

Clearly, cleaning is a demanding repetitive occupation, which incurs a high level of musculoskeletal disorders. The phrase work-related upper limb musculoskeletal disorders includes a variety of upper limb degenerative and inflammatory diseases and disorders, which result in pain and functional impairment. Inappropriate and poor working postures, lack of task variation, poor ergonomic design of work places, poor design of cleaning tools and work organization (e.g., long working hours, low salaries and awkward schedules) are all areas where relatively simple interventions can significantly reduce the rate of exposure to occupational disease. The poor working resources make the high rate of related musculoskeletal disorders for the cleaners. The aim of this study was to compare the musculoskeletal disorders with different height of the cleaners and to evaluate the effect of height on cleaners`working postures in a school environment. Thirty motivated professional female cleaners from one university in Taiwan took part in this survey. Their age ranged from 45 to 65 years and the average length of their work experience was 6.5 years. The survey was carried out according to the following steps: Step 1: Definition of the framework/theme of the survey. Step2: Establishment of the goal, Step3: Nordic Musculoskeletal Questionnaire (NMQ) survey, Step4: Development of a cleaning task analysis, Step5: Rapid Entire Body Assessment (REBA) survey, Step6: Evaluation for NMQ and REBA.

Serum and Pleural Fluid Procalcitonin in Predicting Bacterial Infection in Patients with Parapneumonic Effusion

Yang-Ching Ko,Wen-Pin Wu,Chi-Sen Hsu,Mong-Ping Dai,Chien-Chih Ou,Chih-Hsiung Kao 대한의학회 2009 Journal of Korean medical science Vol.24 No.3

This study evaluated the value of procalcitonin (PCT) levels in pleural effusion to differentiate the etiology of parapneumonic effusion (PPE). Forty-one consecutive PPE patients were enrolled and were divided into bacterial and non-bacterial PPE. Blood and pleural effusion samples were collected for PCT measurement on admission and analyzed for diagnostic evaluation. PCT of pleural fluid was significantly increased in the bacterial PPE group (0.24 ng/mL) compared to the non-bacterial PPE group (0.09 ng/mL), but there was no significant difference for serum PCT. A PCT concentration of pleural fluid >0.174 ng/mL (best cut-off value) was considered positive for a diagnosis of bacterial PPE (sensitivity, 80%; specificity, 76%; AUC, 0.84). Pleural effusion PCT in the bacterial PPE is significantly different from those of the non-bacterial PPE and control groups, so the diagnostic use of PCT still warrants further investigation.

Applications of Hilbert-Huang transform to structural damage detection

Chiou, Dung-Jiang,Hsu, Wen-Ko,Chen, Cheng-Wu,Hsieh, Chih-Min,Tang, Jhy-Pyng,Chiang, Wei-Ling Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.39 No.1

This study investigates the feasibility of detecting structural damage using the HHT method. A damage detection index, the ratio of bandwidth (RB) is proposed. This index is highly correlated or approximately equal to the change of equivalent damping ratio for an intact structure incurring damage from strong ground motions. Based on an analysis of shaking table test data from benchmark models subjected to adjusted Kobe and El Centro earthquakes, the damage detection index is evaluated using the Hilbert-Huang Transform (HHT) and the Fast Fourier Transform (FFT) methods, respectively. Results indicate that, when the response of the structure is in the elastic region, the RB value only slightly changes in both the HHT and the FFT spectra. Additionally, RB values estimated from the HHT spectra vs. the PGA values change incrementally when the structure response is nonlinear i.e., member yielding occurs, but not in the RB curve from the FFT spectra. Moreover, the RB value of the top floor changes more than those from the other floors. Furthermore, structural damage is detected only when using the acceleration response data from the top floor. Therefore, the ratio of bandwidth RB estimated from the smoothed HHT spectra is an effective and sensitive damage index for detecting structural damage. Results of this study also demonstrate that the HHT is a powerful method in analyzing the nonlinear responses of steel structures to strong ground motions.

Applications of Hilbert-Huang transform to structural damage detection

Dung-Jiang Chiou,Wen-Ko Hsu,Cheng-Wu Chen,Chih-Min Hsieh,Jhy-Pyng Tang,Wei-Ling Chiang 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.39 No.1

This study investigates the feasibility of detecting structural damage using the HHT method. A damage detection index, the ratio of bandwidth (RB) is proposed. This index is highly correlated or approximately equal to the change of equivalent damping ratio for an intact structure incurring damage from strong ground motions. Based on an analysis of shaking table test data from benchmark models subjected to adjusted Kobe and El Centro earthquakes, the damage detection index is evaluated using the Hilbert-Huang Transform (HHT) and the Fast Fourier Transform (FFT) methods, respectively. Results indicate that, when the response of the structure is in the elastic region, the RB value only slightly changes in both the HHT and the FFT spectra. Additionally, RB values estimated from the HHT spectra vs. the PGA values change incrementally when the structure response is nonlinear i.e., member yielding occurs, but not in the RB curve from the FFT spectra. Moreover, the RB value of the top floor changes more than those from the other floors. Furthermore, structural damage is detected only when using the acceleration response data from the top floor. Therefore, the ratio of bandwidth RB estimated from the smoothed HHT spectra is an effective and sensitive damage index for detecting structural damage. Results of this study also demonstrate that the HHT is a powerful method in analyzing the nonlinear responses of steel structures to strong ground motions.

Cardiovascular Medication Use and Risk of Acute Exacerbation in Patients With Asthma-COPD Overlap (CVACO Study)

Su Vincent Yi-Fong,Ko Szu-Wen,Chang Yuh-Lih,Chou Yueh-Ching,Lee Hsin-Chen,Yang Kuang-Yao,Chou Kun-Ta,Hsu Chia-Chen 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.3

Purpose: Current clinical guidelines are unclear regarding the association of cardiovascular medication with the risk of acute exacerbation (AE) in patients with asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). Methods: We conducted a retrospective cohort study by interrogating the claims database of Taipei Veterans General Hospital. Patients with coexistent fixed airflow limitation and asthma were enrolled as an ACO cohort between 2009 and 2017. Exposure to cardiovascular medications, including angiotensin converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), non-selective beta-blockers, cardioselective beta-blockers, dihydropyridine (DHP) calcium channel blockers (CCBs), and non-DHP CCBs, in 3-month period each served as time-dependent covariates. Patients receiving a cardiovascular medication ≥ 28 cumulative daily doses were defined as respective cardiovascular medication users. Patients were followed up until December 31, 2018. The primary endpoint was severe AE, defined as hospitalization or emergency department visit for either asthma, COPD, or respiratory failure. The secondary outcome was moderate AE. Results: The final study cohort consisted of 582 ACO subjects, with a mean follow-up period of 2.98 years. After adjustment, ARB (hazard ratio [HR], 0.64, 95% confidence interval [CI], 0.44–0.93, P = 0.019), cardioselective beta-blocker (HR, 0.29, 95% CI, 0.11–0.72, P = 0.008) and DHP CCB (HR, 0.66, 95% CI, 0.45–0.97, P = 0.035) therapies were associated with lower risks of severe AE. ARB (HR, 0.42, 95% CI, 0.30–0.62, P < 0.001) and DHP CCB (HR, 0.55, 95% CI, 0.38–0.80, P = 0.002) therapies were associated with lower risks of moderate AE. Cardioselective beta-blockers, ARBs, and DHP CCBs were associated with lower risks of severe AE in frequent exacerbators. ACEI, non-selective beta-blocker, or non-DHP CCB use did not change the risk of severe AE. Conclusions: ARB, cardioselective beta-blocker, and DHP CCB therapies may lower the risk of AE in patients with ACO.