Reliability-based Evaluation of River-bridge Flood Resistance Ability Via a Visual Inspection Table

Kuo-Wei Liao,Bang-Ho Wu,Wei-Lun Chen 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.9

This research establishes a reliability-based preliminary evaluation table for assessing river-bridge flood resistance. Flood resistance for a river-bridge is affected by numerous factors, including bridge structure, river environment, hydrology, and riverbank protection infrastructure. Flood resistance assessment is a complex issue that involves multiple areas of expertise. A comprehensive assessment process is extremely time-consuming and difficult to implement in practice, especially given the limited time and resources. Many bridges require risk evaluations. A preliminary visual inspection is often conducted in response to these problems. The primary issue with visual inspection is the high subjectivity regarding the understanding and standards for the various indicators. To solve this issue, a Bayesian Network (BN) is proposed to combine the contributions from experts and reliability analyses. Eight bridges are selected for performing FOSM-based reliability calculations using a parameterized ABAQUS model. An ideal preliminary inspection table enables a close relationship with the failure probability that is calculated from an advance analysis. Thus, PSO is employed to maximize the correlation between the scores obtained from the visual inspection table and the failure probability calculated from the BN to establish a reliability-based visual inspection table that provides a strong foundation for a bridge risk analysis.

A Probabilistic Safety Evaluation Framework for Multi-Hazard Assessment in a Bridge using SO-MARS Learning Model

Kuo-Wei Liao,Nhat-Duc Hoang,Jessica Gitomarsono 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.3

A probabilistic evaluation procedure is established to assess a bridge safety against floods and earthquakes, which are the two major threats of a bridge in Taiwan. Scour depth distribution is used to reflect the flood hazard, in which swarm optimized multivariate adaptive regression splines (SO-MARS) is utilized to calculate scour depth density followed by Monte Carlo Simulation (MCS) and a scour risk curve is constructed. Displacement ductility is used to measure the bridge performance under attacks of both hazards through nonlinear time history analyses followed by a power law regression to build the fragility curve. A code-based probabilistic seismic hazard curve is constructed and the joint failure probability under seismic and flood attacks is obtained. A numerical example is provided to illustrate the proposed methodology, in which the nonlinear behaviors in concrete (including core and cover areas), steel bar and soil are included in a bridge model. A threshold scour depth for a given earthquake (e.g., the return period or the peak ground acceleration is given) is derived to meet a specified target reliability. The suggested scour depth is a deterministic number which is immediately applicable in engineering practice.

Scour depth evaluation of a bridge with a complex pier foundation

Kuo-Wei Liao,Yasunori Muto,Jhe-Yu Lin 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.7

A scour depth prediction formula for a river bridge is established using experimental data in which the effects of the pier, pile-capand pile group are considered. More than 170 experimental data entries, including different pier structural sizes, flow depths and soilcovering depths, are collected and verified by existing formulae, which failed to deliver a promising prediction. A machine learningprediction model was then developed to enhance the accuracy. For application purpose, a sequential quadratic programmingoptimization was adopted to construct an explicit prediction formula. The MAPE was significantly improved from 102.8 to 28.9. Theresults indicate that the proposed formula can simultaneously satisfy the requirements of accuracy and simplicity. The proposedformula has the advantages of being conceptually consistent with observed scour behaviors and provides a solid scour depthprediction, which is an important and critical step in the bridge safety evaluation if floods are considered.

Cost Analysis of Impacts of Climate Change on Regional Air Quality

Liao, Kuo-Jen,Tagaris, Efthimios,Russell, Armistead G.,Amar, Praveen,He, Shan,Manomaiphiboon, Kasemsan,Woo, Jung-Hun Informa UK (Taylor Francis) 2010 Journal of the Air & Waste Management Association Vol.60 No.2

Characteristics of Surface Layer Biomass Using Optical and Hydroacoustic Remote Sensing Methods in the Waters of Northeastern Taiwan

Liao, Cheug Hsin,Lee, Kuo Tien,Lee, Ming Anne,Lu, Hsueh Jung 한국수산자원학회 1998 한국수산자원학회지 Vol.1 No.1

Characteristics of oceanographic conditions and surface layer (5-50m) biomass distribution in the waters of northeastern Taiwan, where the Kuroshio Current meets the coastal water of mainland China, were investigated using hydroacoustic survey data, CTD (Conductivity, Temperature and Depth) data and NOAA's AVHRR infrared images. In this region, a cold eddy with low temperature and high salinity was found near the island of Peng - Chia Yu. In the summers of 1994 and 1995, the sea surface temperature isotherms (gradients) were unconducted. The biomass was low and decreased with depth in the center of the eddy. Higher biomass concentrations were found in two nearby areas : the waters near the periphery of the cold eddy and the coastal waters of northern Taiwan. The former had low temperature and high salinity, while the latter had high temperature and low salinity. In mid - April, 1995, the sea surface temperature isotherms (gradients) were very complex. A high biomass area was found in the waters where the warm Taiwan current mixes with continental coastal water of low temperature and low salinity, while low biomass areas were found in the center of the cold eddy (low temperature and high salinity), and the front of the Kuroshio Current (high temperature and high salinity). Since acoustic survey data (Sv) and satellite image data (SST) have an important spatial component, a Geographic Information System (GIS) was used to display and analyze some of these data.

The Inventory and Statistics of Potential Large-scale Landslide Areas in Southern Taiwan

( Kuo-wei Li ),( Chien-yu Lin ),( Jyh-jong Liao ),( Yi-wen Pan ),( Keng-hao Kang ),( Che-ming Yang ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

This study produced an inventory of the 2,523 potential large-scale landslide areas (PLSLAs) in southern Taiwan. These PLSLAs were delineated using LiDAR DEM of 1m resolution after the 2009 Typhoon Morakot by other institutes. Using the inventory, we conducted a statistical analysis of the important geologic and geomorphologic factors possibly related to a PLSLA. The statistical analyses reveal that, among the 2,523 PLSLAs, (1) 82% of elevation are between 750 and 2,750 m, (2) 79% of the area are between 10 and 40 hectares, (3) 76% of the slope height are between 200 and 600 m, (4) 86% of the slope are between 25 and 40 degrees and (5) 83 percent of stream order are less than 3. Rock formations of these PLSLAs range from Oligocene to Miocene; 67% of the strata are slate, and 12% are interbedded of sandstone and shale. This study selected 24 medium to high risk cases of the 2,523 PLSLAs, and interpreted the micro-geomorphological features from 1m LiDAR DEM. The following three patterns were present: (1) PLSLA with clear features of gravitational slope deformation in slope height more than 500 m condition, (2) PLSLA with the relic of paleo landslides induced by gravitational buckling, toppling, or plane sliding, (3) PLSLA with river bank erosion on slope toe and head-cut erosion induced by gully development. Based on statistics, the stream order of the PLSLAs with gravitational slope deformation usually would exceed 3; 83% of PLSLAs are the areas also with paleo large-scale landslide.

Development of a Sorting System for Inspection of Mushroom Mycelium Growth

( Vivian Liao ),( Suming Chen ),( Chao-yin Tsai ),( Kuang-wen Hsieh ),( Kuo-chih Tung ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Mushroom cultivation is one of the important industries in Taiwan's agriculture. In current mushroom cultivation process, which includes spawn production, substrate preparation & bottling, inoculation, spawning, scratching, fruiting, harvest and packing, required a large amount of labor. In this research, the improvement in fault inspection for spawn level and bacterial infection before scratching process was conducted. The aim of this research is to establish an inspection system using machine vision, pneumatic mechanism and Programmable Logic Controller (PLC). First, an experiment-used small lighting chamber was made to study the image processing method, which can get the development (expansion) of self-made simulated samples from its side view image. The accuracy to recognize the fault in self-made simulated samples is up to 99.9%. In real cultivation bottle samples fault inspection, it spent for about 10 seconds and can get well recognition. A prototype of sorting system has also been established to conduct the inspecting process and remove bottles with fault conditions of spawn level and bacterial infection.

Stroke and Bleeding Risk Assessment in Atrial Fibrillation: Where Are We Now?

Ling Kuo,Yi-Hsin Chan,Jo-Nan Liao,Shih-Ann Chen,Tze-Fan Chao 대한심장학회 2021 Korean Circulation Journal Vol.51 No.8

Most important international guidelines recommend the use of CHA2DS2-VASc and HAS-BLED scores for stroke and bleeding risk assessments in atrial fibrillation (AF) patients, respectively. The 2020 AF guidelines of European Society of Cardiology have revised the definition of “C: congestive heart failure (HF)” component, and now patients with either HF with reduced ejection fraction or preserved ejection fraction should be assigned 1 point. Hypertrophic cardiomyopathy was also included. Besides, the revised “V: vascular diseases” component included both prior myocardial infarction and “angiographically significant coronary artery disease”. It is important to understand that the stroke and bleeding risks of AF patients were not static and should be re-assessed regularly. A high HAS-BLED score itself should not be the only reason to withhold or discontinue oral anticoagulants, but remind physicians for the corrections of modifiable bleeding risk factors and more regular follow up. In the future, the AF duration and left atrial function may play an important role for personalized evaluation of individual stroke risk while more studies are necessary.

Antipsychotic Medication in Schizophrenic Patients is Associated with Higher Risks of Developing Bone Fractures and Refractures

Ching-Min Kuo,Wei-Jen Liao,Chun-Che Huang,Tsuo-Hung Lan,Ching-Heng Lin,Shun-Ping Wang,Cheng-Hung Lee,Ping-Wing Lui 대한정신약물학회 2020 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.18 No.4

Objective: The relationship of antipsychotics and the risk of refracture in treated patients is unclear. The aim of this study is to evaluate the association between prolonged antipsychotic and the incidences of bone fractures and refractures in schizophrenia. Methods: This is a retrospective nested case-control study using Taiwan National Health Insurance Research Database recorded from 2000 to 2005, with cases followed up to end of 2011. Total of 7,842 schizophrenic patients, 3,955 had developed bone fractures were compared with 3,887 control subjects matched in age, sex, and index date. Antipsychotic drug exposure was classified based on the drug type and medication duration. Conditional logistic regression analyses were performed. Odds ratio (OR) and confidence interval (CI) were calculated. Results: We found (after adjustments) higher risks of developing fractures under continued use of typical (OR = 1.70; 95% CI, 1.51−1.91) or atypical antipsychotics (OR = 1.43; 95% CI, 1.28−1.60) were found. Additionally, continued use typical (OR = 1.84; 95% CI, 1.35−2.50) or atypical antipsychotics (OR = 1.44; 95% CI, 1.06−1.95) was positively associated with refracture risks. Moreover, refractures were associated with continuous use of chlorpromazine (one typical antipsychotics, OR = 2.45; 95% CI, 1.14−5.25), and risperidone (OR = 1.48; 95% CI, 1.01−2.16) or zotepine (OR = 2.15; 95% CI, 1.06−4.36) (two atypical antipsychotics). Conclusion: Higher risks of bone fracture and refracture were found in schizophrenia under prolonged medication with typical or atypical antipsychotics. We therefore recommend that clinicians should pay more attention on bone density monitoring for patients using long-term antipsychotics.

Practical Aspects of Botulinum Toxin-A Treatment in Patients With Overactive Bladder Syndrome

Chun-Hou Liao,Hann-Chorng Kuo 대한배뇨장애요실금학회 2015 International Neurourology Journal Vol.19 No.4

Intravesical onabotulinumtoxinA (BoNT-A) injection is an effective treatment for overactive bladder syndrome (OAB) that is refractory to antimuscarinics. An injectable dose of 100 U has been suggested to achieve the optimal balance of benefit and safety in patients with OAB. BoNT-A (total volume of 10 mL) was administered as evenly distributed intradetrusor injections (5 U) across 20 sites approximately 1 cm apart (0.5 mL per site) using a flexible or rigid cystoscope. Treatment with BoNT-A was generally well tolerated by most patients, and most treatment-related adverse events were localized to the urinary tract. The prevalence of OAB increases with age, and elderly patients are more vulnerable to complications. The short-term efficacy of intravesical BoNT-A injection for refractory OAB with no treatment-related complications in the elderly population has been documented. Frail elderly patients can experience the same treatment results, such as significantly improved urgent urinary incontinence and quality of life, as young and nonfrail elderly patients with 100-U BoNT-A injections. However, increased risk of larger postvoid residual (PVR) urine and lower long-term success rates were noted in frail elderly patients; around 11% had acute urinary retention, while 60% had PVR urine volume >150 mL after treatment. In addition, intravesical injection of BoNT-A effectively decreased urgency symptoms in elderly patients with OAB and central nervous system lesions. The adverse effects were acceptable, while the long-term effects were comparable to those in patients with OAB without central nervous system lesions. Nonetheless, the possibility of longstanding urinary retention and chronic catheterization in this vulnerable population requires careful evaluation before treatment with intravesical BoNT-A. In conclusion, the current findings indicate that intravesical BoNT-A is an effective and safe treatment for OAB in elderly patients.