Collapse behavior evaluation of asymmetric buildings subjected to bi‐directional ground motion

This paper discusses the collapse behavior of low‐rise plan‐asymmetric buildings under bi‐directional horizontal ground motions and utilizing strength and stiffness degrading nonlinear models. For this purpose, three‐dimensional three‐story and six‐story reinforced concrete frame buildings with uni‐directional mass eccentricities equal to 0% (symmetrical), 10%, 20% and 30% are subjected to nonlinear static (pushover) as well as incremental dynamic analyses using a set of far‐field two‐component ground motions and their performance are assessed on the basis of the safety margin against collapse and its probability of occurrence. Comparison of the collapse margin ratios as well as the fragility curves demonstrates significant reduction of the collapse‐level ground motion intensity with increasing eccentricity in plan. Results also indicate that current seismic design parameters including the response modification (R), overstrength (Ω) and ductility (μ) factors are not appropriate for buildings with high levels of plan eccentricity. Buildings with high values of plan eccentricity do not meet the design target life safety performance level on the basis of the calculated probability of collapse and safety margin against collapse. It appears that re‐evaluation of their design parameters is necessary. Copyright © 2015 John Wiley & Sons, Ltd.     

Astute,fine and fast method of iris segmentation in unlimited circumstances

Neural Computing and Applications - Currently, Iris detection is considered as a significant module for robust biometric systems and high-speed applications such as eye tracking. Most iris...     

Tokamak Coils Materials and Toroidal Field Ripples Calculation Using the Comsol Multiphysics

The ITER superconducting magnet systems consists of four main sub-systems: toroidal field (TF) coils, central solenoid coils, poloidal field coils, and correction coils. Like many other ITER systems, the magnet components are supplied in-kind by six domestic agencies. The technical specifications, manufacturing processes and procedures required to fabricate these components are particularly challenging. The management structure and organization to realize this procurement within the tight ITER construction schedule is very complex. On the other hand, toroidal magnetic field ripple in tokamak is an important issue in plasma equilibrium and stability studies. Toroidal magnetic field is created by toroidal torus with finite number of coils, therefore the field has a ripple in torus space. In this paper, we have reviewed the ITER magnetic coils materials, and also we have estimated the amplitude of TF ripples and its dependence to numbers of coils using the “Comsol Multiphysics” software. The calculations which performed for three: 8, 16 and 32 toroidal coils, indicates that increasing the number of toroidal coils lead to reduction of magnetic field ripple and lead to more stable plasma, but diagnostic access to plasma is reduces.     

Analytical Technique for Determination of Toroidal Plasma Displacement

An analytical technique for the determination of toroidal plasma displacement is presented. First, the plasma horizontal position is calculated from the external vertical field coil characteristics. The calculation is made focusing on the external vertical field coil current and voltage changes due to a horizontal displacement of plasma column. Also for comparison of result, a set of magnetic probes were designed, constructed and used. The results from these two techniques are compared and discussed.     

Study of Effects of the Effective Edge Safety Factor on the Energy confinement Time in IR-T1 Tokamak

We present study of the effects of effective edge safety factor on the energy confinement time in IR-T1 tokamak. For this purpose, four magnetic pickup coils were designed, constructed, and installed on the outer surface of the IR-T1, and then Shafranov parameter is obtained from them. Therefore, the effective edge safety factor obtained. Also, energy confinement time is obtained using diamagnetic loop. Experimental results on IR-T1 show that the maximum energy confinement time relate to the low values of effective edge safety factor (2.5 < q _eff (a) < 2.8). This is agreement with theoretical approach.