A single high-directivity microstrip patch antenna (MPA) having a rectangular profile, which can substitute a linear array is proposed. It is designed by using genetic algorithms with the advantage of not requiring a feeding network. The patch fits inside an area of 2.54 x 0.25, resulting in a broadside pattern with a directivity of 12 dBi and a fractional impedance bandwidth of 4 %. The ante...

This paper presents a method for calculating the directivity of the radiation of sound from a panel or opening, whose vibration is forced by the incidence of sound from the other side. The directivity of the radiation depends on the angular distribution of the incident sound energy in the room or duct in whose wall or end the panel or opening occurs. The angular distribution of the incident sou...

Recent broadband modeling of regional events suggests that vertical directivity is particularly important at high frequency. Conventionally, such directivity is obtained by summing a grid of point sources. This relatively time-consuming procedure can be greatly reduced by introducing directivity time histories appropriate for the various crustal phases in terms of upgoing and downgoing paths th...

The perception of sound in architectural spaces is influenced by two main factors: the properties of the space in which the sound is produced, and the properties of the source producing the sound. This research project uses computational modeling to study the effect of these properties on the binaural response in a virtual space. Two independent parameters were studied: the scattering coefficie...

This paper proposes a new methodology to design optimal antennas for MIMO (Multi-Input Multi-Output) communication systems by using spherical mode expansion. Given spatial channel properties of a MIMO channel, such as the angular profile at both sides, the optimal MIMO antennas should provide the largest channel capacity with a constraint of the limited implementation space (volume). In designi...

The horizontal acoustic backscattering strength of a fish school is an important factor for fisheries and for estimation of the size of a fish school using omnidirectional scanning sonar. However, the backscattering strength of a fish school is influenced by their behavior and orientation because the individual fish in the fish school have strong directivity of target strength. This paper discu...

In order to study the influence of machining methods and parameters on surface quality carbon fiber reinforced composites (CFRP) in cutting process, finite element simulation model ultrasonic-assisted CFRP was established, results show that introduction ultrasonic reduces damage degree tool attached torsional vibration effect is most significant. The torsion longitudinal tests disc were carried...

The human voice is a directional sound source. This property has been explored for more than 200 years, mainly using measurements of participants. Some efforts have made to understand the anatomical parameters that influence speech directivity, e.g., mouth opening, diffraction and reflections due head torso, lips vocal tract. However, these mostly studied separately, without being integrated in...