In this paper, the seismic collapse probability of special steel moment-resisting frame (SSMRF) structures under near fault pulse-like and far fault ordinary ground motions is evaluated through fragility analysis. For this purpose, five sample frames with 3 to 15 stories are designed and imposed to the ground motion excitations with different characteristics. Fragility curves are derived for th...

This paper presents an investigation of a pilot signal influence on directivity of self-phased array under conditions of multipath propagation (either reflections or jamming signals). A suggestion is made that an average reduction in directivity owing to the cutting off (or “dropping out”) of some channels of the array be used as a criterion of this influence. It has been shown that an essentia...

Both diagnostic and therapeutic ultrasound applications require an understanding of the directivity patterns on the transducers to design ultrasound equipment and faithfully characterize the acoustic output from medical ultrasound devices. Since each ultrasound transducer has its own specific directivity pattern, the measurement of the directivity pattern is necessary. The objectives of this wo...

The aim of this research is to create a microphone array on a rigid sphere that could be used for teleconferences and for recording of music with the aim of five-channel loudspeaker surround sound reproduction. Experiments were undertaken, within a MATLAB environment, by running computer simulations that tested the directivity of a rigid sphere microphone array in both near and far field. The s...

For tele-conference systems or voice-controlled systems, the highquality sound capture of distant-talking speech is very important. However, background noise and room reverberations seriously degrade the sound capture quality in real acoustical environments. A microphone array is an ideal candidate for capturing distanttalking speech. With a microphone array, the desired speech signals can be a...

Abstract— This paper describes 2 x 2 triangular microstrip patch antenna using T-junction with quarter wave transformer. By regulating the distance in patch antenna and adjusting feed position, bandwidth can be obtained and by using an array, directivity is enhanced. The requirement of large bandwidth, high directivity, and minimum size leads to the design of 2 x 2 triangular microstrip patch a...

[1] To accurately estimate the seismic energy radiated in an earthquake, it is important to use appropriate corrections for path and source effects. Using slip models obtained by inversion of seismic data, we examine the effect of directivity on estimates of radiated energy and develop a method to correct for this source effect. From our calculations we suggest that the directivity correction f...

We report a high-directivity plasmon-resonant terahertz (THz) emitter (PRE) incorporating a 3D-integrated antenna complex. The emitter structure is based on a high electron mobility transistor having unique doubly interdigitated grating gates as a broadband THz antenna that can convert non-radiative plasmons to radiative electromagnetic waves. Due to the sub-wavelength aperture of practical gra...

This work presents a method to control the perceived distance of an auditory object by changing the directivity pattern of a loudspeaker and consequently the direct-to-reverberant ratio at the listening spot. Control of the directivity pattern is achieved by beamforming using a compact multi-driver loudspeaker unit. A small-sized cubic array consisting of six drivers is assembled, and per drive...

In this paper, the maximization of the directivity of compromise difference patterns in subarrayed monopulse linear array antennas with optimum sum mode is addressed by means of a two-stage excitation matching procedure. The knowledge of the independently optimum difference excitations, which provide the maximum directivity, is exploited with an efficient matching technique based on the contigu...