Role of accidental torsion in seismic reliability assessment for steel buildings

Heui-Yung Chang,Jung-Yu Chen,Chu-Chieh Jay Lin,Ker-Chun Lin 국제구조공학회 2009 Steel and Composite Structures, An International J Vol.9 No.5

This study investigates the role of accidental torsion in seismic reliability assessment. The analyzed structures are regular 6-story and 20-story steel office buildings. The eccentricity in a floor plan was simulated by shifting the mass from the centroid by 5% of the dimension normal to earthquake shaking. The eccentricity along building heights was replicated by Latin hypercube sampling. The fragilities for immediate occupancy and life safety were evaluated using 0.7% and 2.5% inter-story drift limits. Two limit-state probabilities and the corresponding earthquake intensities were compared. The effect of ignoring accidental torsion and the use of code accidental eccentricity were also assessed. The results show that accidental torsion may influence differently the structural reliability and limit-state PGAs. In terms of structural reliability, significant differences in the probability of failure are obtained depending on whether accidental torsion is considered or not. In terms of limit-state PGAs, accidental torsion does not have a significant effect. In detail, ignoring accidental torsion leads to underestimates in low-rise buildings and at small drift limits. On the other hand, the use of code accidental eccentricity gives conservative estimates, especially in high-rise buildings at small drift limits.

3-D NUMERICAL AND EXPERIMENTAL ANALYSIS FOR AIRFLOW WITHIN A PASSENGER COMPARTMENT

Chia-Hung Chien,Yung-Hsin Chen,Shih-Chieh Wu,Jiin-Yuh Jang 한국자동차공학회 2008 International journal of automotive technology Vol.9 No.4

People use cars so frequently that they always consider the air-conditioning, and thermal comfort of the driver and passenger when buying a new car. Therefore accurate simulation of the thermal performance of automobile air conditioners to improve human comfort has become increasingly important. In order to improve the thermal comfort of passengers, 3-D flow motion and thermal behavior within vehicles must be analyzed. In this paper, a numerical simulation was used to investigate thermal behavior in a vehicle. Because air temperature at an air vent is related to the cooling capacity of the air conditioner, the cooling capacity was calculated using ε -NTU (effective number of transfer unit) theoretical equations. Using the air temperature relationship between inlet and outlet vents as boundary conditions, a 3-D unsteady κ -ε turbulent model was used to give a transient analysis simulation of the temperature field and flow conditions in a vehicle’s passenger cabin. Cooling cycle analysis and conjugate heat transfer analysis at the inside surface of the cabin’s ceiling, floor and sides were also considered. The predicted temperature distributions in the vehicles passenger cabin were in good agreement with those obtained experimentally.

Face and Gesture Based Human Computer Interaction

Yo-Jen Tu,Chung-Chieh Kao,Huei-Yung Lin,Chin-Chen Chang 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.9

In this paper, we present a face and gesture based human computer interaction (HCI) system. We combine head pose and hand gesture to control the system. We can identify the positions of the eyes and mouth, and use the face center to estimate the pose of the head. Moreover, we introduce a technique for automatic gesture area segmentation and orientation normalization of the hand gesture. The user does not need to keep gestures in upright position and the system segments and normalizes the gestures automatically. The experimental results show that the proposed approach is accurate with gesture recognition rate of 93.6%. Also, the user can control multiple devices, including robots simultaneously through a wireless network.

Diffusion Tensor-Derived Properties of Benign Oligemia, True “at Risk” Penumbra, and Infarct Core during the First Three Hours of Stroke Onset: A Rat Model

Fang-Ying Chiu,Duen-Pang Kuo,Yung-Chieh Chen,Yu-Chieh Kao,Hsiao-Wen Chung,Cheng-Yu Chen 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.6

Objective: The aim of this study was to investigate diffusion tensor (DT) imaging-derived properties of benign oligemia, true “at risk” penumbra (TP), and the infarct core (IC) during the first 3 hours of stroke onset. Materials and Methods: The study was approved by the local animal care and use committee. DT imaging data were obtained from 14 rats after permanent middle cerebral artery occlusion (pMCAO) using a 7T magnetic resonance scanner (Bruker) in room air. Relative cerebral blood flow and apparent diffusion coefficient (ADC) maps were generated to define oligemia, TP, IC, and normal tissue (NT) every 30 minutes up to 3 hours. Relative fractional anisotropy (rFA), pure anisotropy (rq), diffusion magnitude (rL), ADC (rADC), axial diffusivity (rAD), and radial diffusivity (rRD) values were derived by comparison with the contralateral normal brain. Results: The mean volume of oligemia was 24.7 ± 14.1 mm3, that of TP was 81.3 ± 62.6 mm3, and that of IC was 123.0 ± 85.2 mm3 at 30 minutes after pMCAO. rFA showed an initial paradoxical 10% increase in IC and TP, and declined afterward. The rq, rL, rADC, rAD, and rRD showed an initial discrepant decrease in IC (from -24% to -36%) as compared with TP (from -7% to -13%). Significant differences (p < 0.05) in metrics, except rFA, were found between tissue subtypes in the first 2.5 hours. The rq demonstrated the best overall performance in discriminating TP from IC (accuracy = 92.6%, area under curve = 0.93) and the optimal cutoff value was -33.90%. The metric values for oligemia and NT remained similar at all time points. Conclusion: Benign oligemia is small and remains microstructurally normal under pMCAO. TP and IC show a distinct evolution of DT-derived properties within the first 3 hours of stroke onset, and are thus potentially useful in predicting the fate of ischemic brain.

Differentiation of the Infarct Core from Ischemic Penumbra within the First 4.5 Hours, Using Diffusion Tensor Imaging-Derived Metrics: A Rat Model

Duen-Pang Kuo,Chia-Feng Lu,Michelle Liou,Yung-Chieh Chen,Hsiao-Wen Chung,Cheng-Yu Chen 대한영상의학회 2017 Korean Journal of Radiology Vol.18 No.2

Objective: To investigate whether the diffusion tensor imaging-derived metrics are capable of differentiating the ischemic penumbra (IP) from the infarct core (IC), and determining stroke onset within the first 4.5 hours. Materials and Methods: All procedures were approved by the local animal care committee. Eight of the eleven rats having permanent middle cerebral artery occlusion were included for analyses. Using a 7 tesla magnetic resonance system, the relative cerebral blood flow and apparent diffusion coefficient maps were generated to define IP and IC, half hour after surgery and then every hour, up to 6.5 hours. Relative fractional anisotropy, pure anisotropy (rq) and diffusion magnitude (rL) maps were obtained. One-way analysis of variance, receiver operating characteristic curve and nonlinear regression analyses were performed. Results: The evolutions of tensor metrics were different in ischemic regions (IC and IP) and topographic subtypes (cortical, subcortical gray matter, and white matter). The rL had a significant drop of 40% at 0.5 hour, and remained stagnant up to 6.5 hours. Significant differences (p < 0.05) in rL values were found between IP, IC, and normal tissue for all topographic subtypes. Optimal rL threshold in discriminating IP from IC was about -29%. The evolution of rq showed an exponential decrease in cortical IC, from -26.9% to -47.6%; an rq reduction smaller than 44.6% can be used to predict an acute stroke onset in less than 4.5 hours. Conclusion: Diffusion tensor metrics may potentially help discriminate IP from IC and determine the acute stroke age within the therapeutic time window.

A Systemic Review and Experts’ Consensus for Long-acting Injectable Antipsychotics in Bipolar Disorder

Yuan-Hwa Chou,Po-Chung Chu,Szu-Wei Wu,Jen-Chin Lee,Yi-Hsuan Lee,I-Wen Sun,Chen-Lin Chang,Chien-Liang Huang,I-Chao Liu,Chia-Fen Tsai,Yung-Chieh Yen 대한정신약물학회 2015 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.13 No.2

Bipolar disorder (BD) is a major psychiatric disorder that is easily misdiagnosed. Patient adherence to a treatment regimen is of utmost importance for successful outcomes in BD. Several trials of antipsychotics suggested that depot antipsychotics, including long-acting first- and second-generation agents, are effective in preventing non-adherence, partial adherence, and in reducing relapse in BD. Various long-acting injectable (LAI) antipsychotics are available, including fluphenazine decanoate, haloperidol decanoate, olanzapine pamoate, risperidone microspheres, paliperidone palmitate, and aripiprazole monohydrate. Due to the increasing number of BD patients receiving LAI antipsychotics, treatment guidelines have been developed. However, the clinical applicability of LAI antipsychotics remains a global cause for concern, particularly in Asian countries. Expert physicians from Taiwan participated in a consensus meeting, which was held to review key areas based on both current literature and clinical practice. The purpose of this meeting was to generate a practical and implementable set of recommendations for LAI antipsychotic use to treat BD; target patient groups, dosage, administration, and adverse effects were considered. Experts recommended using LAI antipsychotics in patients with schizophrenia, rapid cycling BD, BD I, and bipolar-type schizoaffective disorder. LAI antipsychotic use was recommended in BD patients with the following characteristics: multiple episodes and low adherence; seldom yet serious episodes; low adherence potential per a physician’s clinical judgment; preference for injectable agents over oral agents; and multiple oral agent users still experiencing residual symptoms.