http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Capacity design by developed pole placement structural control
Fereidoun Amini,Kaveh Karami 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.39 No.1
To ensure safety and long term performance, structural control has rapidly matured over the past decade into a viable means of limiting structural responses to strong winds and earthquakes. Nonlinear response history analysis requires rigorous procedure to compute seismic demands. Therefore the simplified nonlinear analysis procedures are useful to determine performance of the structure. In this investigation, application of improved capacity demand diagram method in the control of structural system is presented for the first time. Developed pole assignment method (DPAM) in structural systems control is introduced. Genetic algorithm (GA) is employed as an optimization tool for minimizing a target function that defines values of coefficient matrices providing the placement of actuators and optimal control forces. The ground acceleration is modified under induced control forces. Due to this, performance of structure based on improved nonlinear demand diagram is selected to threshold of nonlinear behavior of structure. With small energy consumption characteristics, semi-active devices are especially attractive solutions for limiting earthquake effects. To illustrate the efficiency of DPAM, a 30-story steel moment frame structure employing the semi-active control devices is applied. In comparison to the widely used linear quadratic regulation (LQR), the DPAM controller was shown to be just as effective and better in the reduction of structural responses during large earthquakes.
Fereidoun Azizi,Navid Saadat,Mir Alireza Takyar,Hengameh Abdi,Ladan Mehran,Atieh Amouzegar 대한내분비학회 2022 Endocrinology and metabolism Vol.37 No.6
Background: This study compared the degree of sustained control of hyperthyroidism in patients with toxic multinodular goiter(TMNG) treated with long-term methimazole (LT-MMI) or radioactive iodine (RAI). Methods: In this clinical trial, 130 untreated patients with TMNG were randomized to either LT-MMI or RAI treatment. Bothgroups were followed for 108 to 148 months, with median follow-up durations of 120 and 132 months in the LT-MMI and RAIgroups, respectively. Both groups of patients were followed every 1 to 3 months in the first year and every 6 months thereafter. Results: After excluding patients in whom the treatment modality was changed and those who were lost to follow-up, 53 patients inthe LT-MMI group and 54 in the RAI group completed the study. At the end of the study period, 50 (96%) and 25 (46%) patientswere euthyroid, and two (4%) and 25 (46%) were hypothyroid in LT-MMI and RAI groups, respectively. In the RAI group, four(8%) patients had subclinical hyperthyroidism. The mean time to euthyroidism was 4.3±1.3 months in LT-MMI patients and 16.3±15.0 months in RAI recipients (P<0.001). Patients treated with LT-MMI spent 95.8%±5.9% of the 12-year study period in a euthyroid state, whereas this proportion was 72.4%±14.8% in the RAI-treated patients (P<0.001). No major treatment-related adverseevents were observed in either group. Conclusion: In patients with TMNG, LT-MMI therapy is superior to RAI treatment, as shown by the earlier achievement of euthyroidism and the longer duration of sustained normal serum thyrotropin.
Adaptive control of rotationally non-linear asymmetric structures under seismic loads
Fereidoun Amini,Hassan Rezazadeh,Majid Amin Afshar 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.6
This paper aims to inspect the effectiveness of the Simple Adaptive Control Method (SACM) to control the response of asymmetric buildings with rotationally non-linear behavior under seismic loads. SACM is a direct control method and was previously used to improve the performance of linear and non-linear structures. In most of these studies, the modeled structures were two-dimensional shear buildings. In reality, the building plans might be asymmetric, which cause the buildings to experience torsional motions under earthquake excitation. In this study, SACM is used to improve the performance of asymmetric buildings, and unlike conventional linear models, the non-linear inertial coupling terms are considered in the equations of motion. SACM performance is compared with the Linear Quadratic Regulator (LQR) algorithm. Moreover, the LQR algorithm is modified, so that it is appropriate for rotationally non-linear buildings. Active tuned mass dampers are used to improve the performance of the modeled buildings. The results show that SACM is successful in reducing the response of asymmetric buildings with rotationally non-linear behavior under earthquake excitation. Furthermore, the results of the SACM were very close to those of the LQR algorithm.
Optimized and Decentralized Pulse Control of Seismically Excited Steel Structures
Fereidoun Amini,Maryam Hassanali,Majd Javanbakht 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.2
The idea of decomposing a centralized complicated system into several synchronous decentralized subsystems has been resulted into the development of decentralized control methods. In this study, a decentralized pulse control scheme is presented based on the theory of Inclusion Principle for steel systems comprising a multi-overlapping structure. The proposed control algorithm is basically an active control system that generates corrective pulses at each moment when the displacement or acceleration exceeds the predefined threshold. In order to evaluate the performance of proposed control system, a numerical study is conducted. The control system is implemented for two linear structural models of five- and twenty-story steel buildings. An optimization algorithm (PSO) is also used to determine the locations of required control inputs in the 20-story building. The results show that the proposed algorithm can substantially mitigate the structural response under different earthquake records (for 5-story model) and different subsystem configurations (for 20-story model).
BIPROJECTIVITY OF MATRIX BANACH ALGEBRAS WITH APPLICATION TO COMPACT GROUPS
Fereidoun Habibian,Razieh Noori 한국수학교육학회 2018 純粹 및 應用數學 Vol.25 No.2
In this paper, the necessary and sufficient conditions are considered for biprojectivity of Banach algebras □p(I). As an application, we investigate biprojec-tivity of convolution Banach algebras A(G) and L2(G) on a compact group G.
Fereidoun Forghani,S.M.E. Rahman,박명수,박중현,박지용,송경빈,오덕환 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.1
Effect of ultrasonication (40 kHz) to enhance low concentration electrolyzed water (LcEW) efficacy for microbial decontamination on lettuce leaves was investigated. Lettuce was separately treated with LcEW, ultrasonication,LcEW combined with ultrasonication, LcEW followed by ultrasonication, and ultrasonication followed by LcEW for 1, 3, and 5 min for each step at room temperature. The highest reduction (2.3 log CFU/g) in total bacteria count (TBC) was resulted from ultrasonication followed by LcEW. Subsequently, the effect of temperature was studied resulting in 2.6 and 3.18 log CFU/g reduction of TBC and Escherichia coli O157:H7 respectively, in 3 min ultrasonication followed by 3 min LcEW treatment at 40ºC. This optimum treatment also prevented lettuce from reaching 7.0 log CFU/g in TBC until the end of the 6 day storage at 10ºC. Therefore, this newly developed approach may result in improved microbiological safety and enhanced shelf life of produce.