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.

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.

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.

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.

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.

Local Structure Distortion in LiCu₂O₂ Single Crystal at Low Temperature

Tzu-Wen Huang,Kuo-Wei Yeh,Kuan-Li Yu,Yen-Fa Liao,Maw-Kuen Wu 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Evolution of Multi-temporal Landslides at Luhu, Miaoli County, Taiwan

( Che-ming Yang ),( Keng-hao Kang ),( Kuo-wei Li ),( Hui-jung Wang ),( Ching-ping Hsiao ),( Jyh-jong Liao ),( Yii-wen Pan ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

A deep-seated landslide took place in Luhu, Miao-Li, Taiwan during intermittent rainfall in April 2018; initially, there were successive rock falls and gully erosion then leaded to a deep-seated landslide failure eventually. This study aims to understand the failure mechanism and the process of deep-seated failure. The study site is a steep anaclinal slope consisting of the Miocence Shihti Formation with thick sandstone, interbedded of sandstone and shale. We collected multi-temporal ortho-images and digital elevation (surface) models from 1980 to 2019 for geological investigation, geomorphological interpretation and numerical simulation. The images reveal several slope failures at 1998, 2003, 2005, 2009, 2015, 2017 and 2018 with various volume and failure types. The study area contains three sub-regions: the north, the northwest and the southwest slopes. The slope failure occurred repeatedly inside the north and the northwest slopes in the early stage. Gully erosion in the southwest slope progressed to a landslide on April 5, 2018 first and expanded to cover the deep-seated landslide failure in the northwest slope eventually; the slope failure resulted in a natural dam. After the landslide, several open cracks appeared near to the crown. The estimated maximum thickness, area and volume of the deep-seated landslide are ~60 m, 65,000 m2 and ~2 Mm3, respectively. Based on these results, we also performed a series of numerical simulation using the software RAMMS to interpret the run out and the deposition of this landslide case.

Mahonia oiwakensis Extract and Its Bioactive Compounds Exert Anti-Inflammatory Activities and VEGF Production Through M2-Macrophagic Polarization and STAT6 Activation

Yea-Chen Liu,Yu-Ying Hsiao,Kuo-Lung Ku,Hui-Fen Liao,Wei-Chun Chao 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.7

Macrophages play an indispensable role in the host immune defense. Macrophages can undergo polarization into classically (M1) and alternatively (M2) activated macrophages. M1 macrophages activate immune and inflammatory response, while M2 macrophages are involved in tissue remodeling. Mahonia oiwakensis (Mo) is a herbal medicine in Asia used for its anti-inflammatory and analgesic properties; however, the mechanism is unclear. This study analyzed the effect of Mo extracts and its effects on the polarization of both macrophage RAW264.7 cells and mouse splenic macrophages. Water (Mo-W) and EtOH extracts (Mo-E) did not change the viability of RAW264.7 cells, whereas Mo-E inhibited nitric oxide (NO) production. The major compounds, berberine and palmatine, decreased the viability and NO levels of cells. The secretion of inflammatory cytokines CXCL16, IL-6, L-selectin, MCP1, RANTES, and sTNF-R1 was downregulated, whereas the production of vascular endothelial growth factor (VEGF) was upregulated by Mo-E, berberine, and palmatine treatments. Mo-E, berberine, and palmatine stimulated the expression of macrophage CD68 and M2-type CD204 markers, decreased M1-mediated p-STAT1 and NF-κB, and increased M2-mediated p-STAT6 expression. Similar effects on M2 polarization were also observed in splenic macrophages from mice. In conclusion, Mo-E, berberine, and palmatine modulated macrophages through the suppression of M1-mediated inflammation and the recruitment of M2-mediated VEGF secretion and STAT6 expression.

A Methodology to Build a Groutability Formula via a Heuristic Algorithm

Chien-Lin Huang,Jen-Chen Fan,Kuo-Wei Liao,Tsung-Hsun Lien 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.1

The goal of this study is to provide a methodology to develop a groutability (N) formula of sandy silt soils using microfine cement grouts in a permeation grouting. Because the Fines Content (FC) of the sandy silt soils studied is relatively high, and the size of the grouts used is significantly smaller than the Portland cement, the existing empirical formulas cannot deliver a promising prediction of N. Support Vector Machines (SVMs) is an alternative tool used to predict N. However, SVMs do not provide an explicit formula,which creates an obstacle for practical engineers. Thus, a heuristic algorithm (the Tabu search, TS) was used to build the prediction formula. A total of 240 in-situ data samples were analyzed to ensure the accuracy of the proposed formula. The format of the existing empirical formula was adopted in the proposed TS-based formula. Four parameters were considered in our TS models: the effective soil particle size (D10), the soil particle size (D15), the water-to-cement ratio (w/c) and the FC. The prediction accuracy of the TSbased formula was approximately 94.17%, indicating that the proposed formula is a suitable tool. Because the proposed formula has a similar format to that of formulas that are typically used, the proposed approach can be implemented readily in practical engineering settings. Note that the proposed formula was only verified by the collected data samples, the suitability of applying the built formula to other conditions needs more investigation.

Geometry Optimization of a Metallic Flexor for Flat Wipers

Huang Ting Chuan,Tsai Jian Wei,Liao Kuo Chi 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.3

In recent years, flat wipers are gradually adopted in the industry of transportation due to the rather simple structure than the standard wiper. A procedure is developed to evaluate the appropriateness of the geometry of a metallic flexor, one of major components of the flat wiper, in this study. The flexor is compressed against a level surface and the corresponding pressure distribution under the flexor is measured by using piezoelectric sensors. Several geometry parameters built in a three-dimensional flexor model are investigated to appraise their influences on the corresponding pressure distribution. A process automation software linked to a computer-aided drawing and a finite element analysis commercial packages are utilized, based on the self-defined performance index, to pursue parameter arrangements proper for the pressure distribution. The present procedures are next applied to a curved windshield glass to evaluate optimized flexor geometries at various locations. Appropriate flexors for the windshield glass are then determined and practically sampled. Dynamic wiping simulations of the integrated flat wiper on the windshield glass are furthermore carried out and the pressure distributions over the sweep range are estimated. Wiping capabilities of the wiper are experimentally observed and compared with the associated numerical results.