Column-loss response of RC beam-column sub-assemblages with different bar-cutoff patterns

Meng-Hao Tsai,Jun-Kai Lu,Bo-Hong Huang 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.6

Static loading tests were carried out in this study to investigate the effect of bar cutoff on the resistance of RC beam-column sub-assemblages under column loss. Two specimens were designed withcontinuous main reinforcement. Four others were designed with different types of bar cutoff in the mid-span and/or the beam-end regions. Compressive arch and tensile catenary responses of the specimens under gravitational loading were compared. Test results indicated that those specimens with approximately equal moment strength at the beam ends had similar peak loading resistance in the compressive arch phase but varied resistance degradation in the transition phase because of bar cutoff. The compressive bars terminated at one-third span could help to mitigate the degradation although they had minor contribution to the catenary action. Among those cutoff patterns, the K-type cutoff presented the best strength enhancement. It revealedthat it is better to extend the steel bars beyond the mid-span before cutoff for the two-span beams bridgingover a column vulnerable to sudden failure. For general cutoff patterns dominated by gravitational and seismic designs, they may be appropriately modified to minimize the influence of bar cutoff on the progressive collapse resistance.

Chord rotation demand for effective catenary action of RC beams under gravitational loadings

Meng-Hao Tsai 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.2

Many experimental and analytical studies have been conducted with beam-column subassemblages composed of a two-span beam to investigate the progressive collapse resistance of RC frames. Most study results reveal a strength-decreased transition phase in the nonlinear static load-deflection curve, which may induce dynamic snap-through response and increase the chord rotation demand for effective catenary action (ECA). In this study, the nonlinear static response is idealized as a piecewise linear curve and analytical pseudo-static response is derived for each linearized region to investigate the rotation demands for the ECA of the two-span RC beams. With analytical parameters determined from several published test results, numerical analysis results indicate that the rotation demand of 0.20 rad recommended in the design guidelines does not always guarantee the ECA. A higher rotation demand may be induced for the two-span beams designed with smaller span-to-depth ratios and it is better to use their peak arch resistance (PAR) as the collapse strength. A tensile reinforcement ratio not greater than 1.0% and a span-to-depth ratio not less than 7.0 are suggested for the two-span RC beams bridging the removed column if the ECA is expected for the collapse resistance. Also, complementary pseudo-static analysis is advised to verify the ECA under realistic dynamic column loss even though the static PAR is recovered in the nonlinear static response. A practical empirical formula is provided to estimate an approximate rotation demand for the ECA.

Column-loss response of RC beam-column sub-assemblages with different bar-cutoff patterns

Tsai, Meng-Hao,Lua, Jun-Kai,Huang, Bo-Hong Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.6

Static loading tests were carried out in this study to investigate the effect of bar cutoff on the resistance of RC beam-column sub-assemblages under column loss. Two specimens were designed with continuous main reinforcement. Four others were designed with different types of bar cutoff in the mid-span and/or the beam-end regions. Compressive arch and tensile catenary responses of the specimens under gravitational loading were compared. Test results indicated that those specimens with approximately equal moment strength at the beam ends had similar peak loading resistance in the compressive arch phase but varied resistance degradation in the transition phase because of bar cutoff. The compressive bars terminated at one-third span could help to mitigate the degradation although they had minor contribution to the catenary action. Among those cutoff patterns, the K-type cutoff presented the best strength enhancement. It revealed that it is better to extend the steel bars beyond the mid-span before cutoff for the two-span beams bridging over a column vulnerable to sudden failure. For general cutoff patterns dominated by gravitational and seismic designs, they may be appropriately modified to minimize the influence of bar cutoff on the progressive collapse resistance.

Development of a 2-Chamber Culture System for Impedimetric Monitoring of Cell-cell Interaction

Kin Fong Lei,Meng-Tsan Tsai,Ming-Hong Zhong,Chia-Hao Huang,Ngan-Ming Tsang,Ming-Yih Lee 한국바이오칩학회 2017 BioChip Journal Vol.11 No.2

In cancer research, study of cell-cell interaction is important to understand tumor initiation, progression, metastasis, and therapeutic resistance. Conventionally, transwell system was adopted and cell proliferation was quantified by end-point bio-assays. The operations are labor-intensive and time-consuming while studying of the dynamic cellular responses of cell-cell interaction. Although impedance measurement was suggested to be a promising technique to monitor cellular responses, electrodes cannot be integrated into the transwell for the measurement purpose. In this work, a 2-chamber culture system incorporated with impedance measurement technique was developed to quantitatively study cell-cell interaction. The chamber was composed of 2 sub-chambers separated with a barrier. By this design, two types of cells could be independently cultured and concurrently monitored under common medium supplied. Cell-cell interaction was demonstrated by aberrant cell proliferation induced by the EGF secreted from the transfected cells cultured on another sub-chamber. Real-time and non-invasive monitoring of cell-cell interaction was successfully demonstrated. This work provides a practical solution for monitoring the dynamic cellular responses of cellcell interaction during the culture course. It is a reliable and convenient platform and facilitate more quantitative assessments in cancer research.

Improving Scanner Data Collection in P4-based SDN

Yun-Zhan Cai,Chih-Hao Lai,Yu-Ting Wang,Meng-Hsun Tsai 한국통신학회 2020 한국통신학회 APNOMS Vol.2020 No.09

Port scanning is a well-known behavior when a botnet searches target devices. To detect port scanning accurately, data with high discriminatory power are indispensable. Most related works, however, focus on data analysis methods but neglect storage limitations of switches, which makes their methods impractical. Therefore, we propose a new data collection method for collecting network information of port scanning in P4-based SDN named 0-replacement. Through simulations, we compare the 0-replacement method with two classic data collection methods. Results show that the 0-replacement method improves the true positive ratio by at least 25 percentage points but only consumes 0.36% memory space.

Recent Research and A, pp.ication of Earthquake Protection System in Taiwan

Chang Kuo Chun,Tsai Meng Hao 한국지진공학회 1998 한국지진공학회논문집 Vol.2 No.3

Research and a, pp.ication of earthquake protection system in Taiwan have become very active since about ten years ago. Many passive isolators, etc., have been studied extensively. These studies have resulted in a few practical a, pp.ications and proposals of two draft design provisions for seismic isolation design of bridges and buildings. In addition to the pass control, analytical studies on active semi-active control have also been very active and the experimental studies have scheduled in the near future. This paper summarise the progress on recent research and a, pp.ication of earthquake protection systems in Taiwan. The emphases are given to the control systems that have been a, pp.ied in practical a, pp.ications.

The seasonal detection of AcSBV (Apis cerana sacbrood virus) prevalence in Taiwan

Yu-Shin Nai,Chong-Yu Ko,Pei-Shou Hsu,Wen-Shi Tsai,Yue-Wen Chen,Meng-Hao Hsu,I-Hsin Sung 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

The epizootic disease caused by Apis cerana sacbrood virus (AcSBV) occurred in Eastern hive bee, A. cerana, since2015 in Taiwan. A large-scale survey of this disease from September and December 2016 in Taiwan was performedincluding symptom check and molecular identification in honey bees of A. cerana hives and several A. mellifera hives, which were co-cultured with A. cerana. Based on the nucleotide sequences of partial VP1, thephylogenetic analysis with those of the known AcSBV isolates revealed that most of AcSBV isolates from Taiwanwere closely relative to SBV-FZ and -JL isolates from China, whereas only one sample (N15-5-1) was in a distinctcluster, which was closely relative to SBV-LN from China too. The AcSBV prevalence was occurring in A. ceranahives in most areas of Taiwan except for those in Hualien and Pingtung Counties in Taiwan. Notably, the AcSBVprevalence rate showed the temporal increase from 47.1% to 69.6% within 4 months. In addition, 37.5% ofAcSBV prevalence rate was found in A. mellifera hives. It showed that A. mellifera was also susceptible to AcSBVinfection. The present results would provide the information on the epidemiology and for prospective research.

The effect of diabetes and prediabetes on the prevalence, complications and mortality in nonalcoholic fatty liver disease

Cheng Han Ng,Kai En Chan,Yip Han Chin,Rebecca Wenling Zeng,Pei Chen Tsai,Wen Hui Lim,Darren Jun Hao Tan,Chin Meng Khoo,Lay Hoon Goh,Zheng Jye Ling,Anand Kulkarni,Lung-Yi Loey Mak,Daniel Q Huang,Mark C 대한간학회 2022 Clinical and Molecular Hepatology(대한간학회지) Vol.28 No.3

Background/Aims: Nonalcoholic fatty liver disease (NAFLD) is closely associated with diabetes. The cumulative impact of both diseases synergistically increases risk of adverse events. However, present population analysis is predominantly conducted with reference to non-NAFLD individuals and has not yet examined the impact of prediabetes. Hence, we sought to conduct a retrospective analysis on the impact of diabetic status in NAFLD patients, referencing non-diabetic NAFLD individuals. Methods: Data from the National Health and Nutrition Examination Survey 1999–2018 was used. Hepatic steatosis was defined with United States Fatty Liver Index (US-FLI) and FLI at a cut-off of 30 and 60 respectively, in absence of substantial alcohol use. A multivariate generalized linear model was used for risk ratios of binary outcomes while survival analysis was conducted with Cox regression and Fine Gray model for competing risk. Results: Of 32,234 patients, 28.92% were identified to have NAFLD. 36.04%, 38.32% and 25.63% were non-diabetic, prediabetic and diabetic respectively. Diabetic NAFLD significantly increased risk of cardiovascular disease (CVD), stroke, chronic kidney disease, all-cause and CVD mortality compared to non-diabetic NAFLD. However, prediabetic NAFLD only significantly increased the risk of CVD and did not result in a higher risk of mortality. Conclusions: Given the increased risk of adverse outcomes, this study highlights the importance of regular diabetes screening in NAFLD and adoption of prompt lifestyle modifications to reduce disease progression. Facing high cardiovascular burden, prediabetic and diabetic NAFLD individuals can benefit from early cardiovascular referrals to reduce risk of CVD events and mortality.