A study on pushover analyses of reinforced concrete columns

Kuang-Yen Liu,Chin-Kuo Su,I-Chau Tsai,Yu-Chi Sung,Kuo-Chun Chang 국제구조공학회 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.1

This paper proposes a realistic approach to pushover analyses of reinforced concrete (RC) structures with single column type and frame type. The characteristic of plastic hinge of a single RC column subjected to fixed axial load was determined first according to column’s three distinct failure modes which were often observed in the experiments or earthquakes. By using the determined characteristic of plastic hinge, the pushover analyses of single RC columns were performed and the analytical results were investigated to be significantly consistent with those of cyclic loading tests. Furthermore, a simplified methodology considering the effect of the variation of axial force for each RC column of the frame structure during pushover process is proposed for the first time. It would be helpful in performing pushover analysis for the structures examined in this study with efficiency as well as accuracy.

Central Pontine Myelinolysis in a Normonatremic Patient with Depression

Yu Chia Liu,Yen Kuang Yang,Po See Chen,Wei Hung Chang 대한정신약물학회 2021 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.19 No.3

A 76-year-old male presented with a recurrent depressive episode, an unsteady gait and cognitive impairment. Extensive blood tests, including hemogram, biochemical tests, folic acid, vitamin B12, and thyroid hormone, showed normal results. With the exception of the unsteady gait, neurological examination was negative. Brian magnetic resonance imaging (MRI) showed the typical feature of central pontine myelinolysis (CPM); however, there was no history of alcoholism, liver transplantation, malnutrition or rapid correction of hyponatremia. The patient had taken venlafaxine to treat major depressive disorder for more than 20 years. After discontinuation of venlafaxine, the unsteady gait gradually resolved, and subsequent MRI revealed reduction of the lesions over 6 months. We discuss herein the possible correlation between chronic use of venlafaxine and CPM.

Poster Session : PS 0088 ; Cardiology : Paradoxical Stroke after Complex Coronary Intervention in a Patient with End-Stage Renal Disease

( Cheng Wei Liu ),( Jen Kuang Lee ),( Yen Jun Lai ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

The 75-year-old man underwent percutaneous coronary intervention(PCI) for atherosclerosis coronary artery disease. He had end-staged renal disease with maintenance hemodialysis. Right hemiparesis developed ten hours after the procedure. A computed tomography (CT) of brain demonstrated a hyperdense sucal or cortial lesion in the left frontal lobe (Figure 1). This image fi nding suggested subarachnoid hemorrhage. Dual antiplatelet agents (DAPT) were disrupted transiently. A magnetic resonance imaging (MRI) of brain showed high signal in the left precentral gyrus in diffusion weighted imaging (Figure 2) with corresponding hypointensity in apparent diffusion coeffi ciency imaging (Figure 3), suggestive of an acute infarct. After appropriate treatment for acute ischemic stroke and resuming DAPT immediately, he was discharged uneventfully a week later. Disruption of DAPT signifi cantly increased major cardiovascular events after PCI, especially within 7 days (1). In patients with neurological defi cits after coronary intervention is performed, urgent MRI is necessary to differentiate hemorrhagic strokes from ischemic insults with contrast extravasations from the damaged brainblood barrier. Minimizing window period of DAPT is emphasized in patients with suspicious paradoxical stroke. Reference 1. Mehran R, Baber U, Steg PG, et al. Cessation of dual antiplatelet treatment and cardiac events after percutaneous coronary intervention (PARIS): 2 year results from a prospective observational study. Lancet 382:1714-22, 2013.

A study on pushover analyses of reinforced concrete columns

Sung, Yu-Chi,Liu, Kuang-Yen,Su, Chin-Kuo,Tsai, I-Chau,Chang, Kuo-Chun Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.1

This paper proposes a realistic approach to pushover analyses of reinforced concrete (RC) structures with single column type and frame type. The characteristic of plastic hinge of a single RC column subjected to fixed axial load was determined first according to column's three distinct failure modes which were often observed in the experiments or earthquakes. By using the determined characteristic of plastic hinge, the pushover analyses of single RC columns were performed and the analytical results were investigated to be significantly consistent with those of cyclic loading tests. Furthermore, a simplified methodology considering the effect of the variation of axial force for each RC column of the frame structure during pushover process is proposed for the first time. It would be helpful in performing pushover analysis for the structures examined in this study with efficiency as well as accuracy.

Accuracy assessment of real-time hybrid testing for seismic control of an offshore wind turbine supporting structure with a TMD

Lyan-Ywan Lu,Ging-Long Lin,Kai-Ting Lei,Shih-Wei Yeh,Kuang-Yen Liu 국제구조공학회 2023 Smart Structures and Systems, An International Jou Vol.31 No.6

In this study, the accuracy of a real-time hybrid test (RTHT) employed for a performance test of a tuned mass damper (TMD) on an offshore wind turbine (OWT) with a complicated jacket-type supporting structure is quantified and evaluated by comparing the RTHT results with the experimental data obtained from a shaking table test (STT), in which a 1/25- scale model for a typical 5-MW OWT controlled by a TMD was tested. In the RTHT, the jacket-type OWT structure was modelled using both multiple-DOF (MDOF) and single-DOF (SDOF) numerical models. When compared with the STT test data, the test results of the RTHT show that while the SDOF model, which requires less control computational time, is able to well predict the peak responses of the nacelle and TMD only, the MDOF model is able to effectively predict both the peak and over-all time-history responses at multiple critical locations of an OWT structure. This also indicates that, depending on the type of structural responses considered, an RTHT with either an SDOF or a MDOF model may be a promising alternative to the STT to assess the effectiveness of a TMD for seismic mitigation in an OWT context.

Treatment Retention Rates of 3-monthly Paliperidone Palmitate and Risk Factors Associated with Discontinuation: A Population-based Cohort Study

Chien-Heng Lin,Huang-Li Lin,Chih-Lin Chiang,Yi-Wen Chen,Yan-Fang Liu,Yen Kuang Yang,Chao-Hsiun Tang 대한정신약물학회 2023 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.21 No.3

Objective: Limited evidence exists regarding real-world 3-monthly paliperidone palmitate (PP3M) treatment retention and associated factors. Methods: We conducted a retrospective, nationwide cohort study using the Taiwan National Health Insurance Research Database between October 2017 and December 2019. Adult patients with schizophrenia initiated on PP3M were enrolled. The primary outcomes were time to PP3M discontinuation, time to psychiatric hospitalization, and the proportions of patients receiving the next PP3M dose within 120 days among first-, second-, and third-dose completers. Key covariates included prior PP1M duration and adequate PP3M initiation. Results: The PP3M treatment retention rates were 79.7%, 66.3%, and 52.5% after 6, 12, and 24 months, respectively, with 86.4%, 90.6%, and 90.0% of respective first-, second-, and third-dose completers receiving the next PP3M dose. Adequate PP3M initiation and prior PP1M treatment duration > 180 days were associated with favorable PP3M treatment retention. In multivariate analyses, PP1M durations of 180−360 days (adjusted relative risk [aRR], 1.76) or < 180 days (aRR, 2.79) were associated with PP3M discontinuation at the second dose. Inadequate PP3M initiation was associated with discontinuation at the third dose (aRR, 2.18). Patients fully adherent to PP3M treatment in the first year had a higher probability of being free from psychiatric hospitalization (86.7% at 2 years), compared with those partially adherent or non-adherent to PP3M in the first year. Conclusion: Prior PP1M duration and adequate PP3M initiation are major factors affecting PP3M treatment retention. Higher PP3M treatment retention is associated with a lower risk of psychiatric hospitalization.