Fling-step and forward directivity are two important characteristics of near-field earthquakes. Forward directivity occurs when the rupture propagates toward the site and arises in fault‐normal direction for strike‐slip faults. Fling-step is the consequence of permanent ground displacement imposed by near-field earthquakes and arises in strike-slip faults in the strike parallel direction. Fling...

Pipa is one of the most important Chinese traditional plucked instruments, but its directivity has never been measured systematically. In western, directivity of loudness for western instruments is deeply researched through analysis of sound pressure level, whereas the directivity of timbre is seldom studied. In this paper, a new method for directivity of timbre was proposed, and horizontal dir...

in this paper a simple model of a three story building with inclined first-story columns has presented. the stories are supposed to be rigid and are connected to axially rigid mass less columns by elasto-plastic rotational springs and linear rotational dampers. the considered model is subjected to horizontal component of fault normal pulse with different magnitudes and the governed nonlinear di...

One of the greatest advantages of using complex coordinates in the study of rotating machinery is the gain of physical insight into the forward and backward precessional modes. Together with the complex modal analysis formulation, other interesting tools (like the Shape and Directivity Index Plot) were developed to characterize the shape and directivity of the whirl modes. These tools are helpf...

This paper presents a practical methodology for optimization of concentrically braced steel frames subjected to forward directivity near-fault ground motions, based on the concept of uniform deformation theory. This is performed by gradually shifting inefficient material from strong parts of the structure to the weak areas until a state of uniform deformation is achieved. In this regard, to ove...

Multimode sound radiation from an unflanged, semi-infinite, rigid-walled circular duct with uniform subsonic mean flow everywhere is investigated theoretically. The multimode directivity depends on the amplitude and directivity function of each individual cut-on mode. The amplitude of each mode is expressed as a function of cut-on ratio for a uniform distribution of incoherent monopoles, a unif...

The triple impulse input is used as a simplified version of the forward-directivity near-fault ground motion and a closed-form solution of the elastic–plastic response of a structure by this triple input is obtained. It is noteworthy that only the free-vibration appears under such triple impulse input. An almost critical excitation is defined and its response is derived. The energy approach pla...

The present study reveals the existence of an intrinsic spatial code within neuronal spikes that predicts behavior. As rats learnt a T-maze procedural task, simultaneous changes in temporal occurrence of spikes and spike directivity are evidenced in “expert” neurons. While the number of spikes between the tone delivery and the beginning of turn phase reduced with learning, the generated spikes ...

In this article, to study the effect of pulse-type near-fault earthquakes on the seismic demands of steel moment frames, 15-story 2D-frame was analyzed under the influence of 20 near-fields with forward directivity effect and 2 far-field records. The relationship between Effective Cyclic Energy, ECE and displacement demands, velocity and hysteretic curve of SDOF systems in two near- and far-fau...

Recorded ground motions in near fault region have completely distinct nature from others that recorded in far field of the fault. Near source outcomes cause much of the seismic energy to appear in a single large and long period pulse at the beginning of the velocity record. Assaluyeh complex is located near the reverse Assaluyeh fault that is a segment of Mountain Front Fault. This complex cont...