Abstract: Disclosed are ultrasonic wireless power transmitter and receiver apparatuses, and a method for wireless charging thereof.

Abstract: The present disclosure relates to security system and method based on sound field variation pattern. The present disclosure identifies a slow variation pattern of a acoustic transfer function occurring due to a gradual change in temperature and humidity of air according to a change in time and a change in a characteristic of an acoustic element, from a sudden sound field variation pattern within an internal space occurring due to an intrusion from an outside, activation of an air conditioning and heating device, and the like, or within a surveillance space induced by a change in an acoustic physical property. The present disclosure identifies sound field variation patterns occurring due to a change in an acoustic structure by an intrusion and a change in temperature and convection by air conditioning and heating. The present disclosure stores and verifies image information using an image obtaining apparatus.

Abstract: Provided is an active piezoelectric energy harvester, which can control a direct current voltage applied to an embedded variable capacitance layer to precisely adjust a resonance frequency in real time, and thus achieve a simpler structure and a smaller size compared to a conventional one that adjusts the resonance frequency using a separate variable capacitor provided outside. Further, the active piezoelectric energy harvester can precisely adjust the resonance frequency even when the frequency of vibration varies over time as in a real natural vibration environment or when it is degraded to undergo a variation in its own resonance frequency, and thus can continuously maintain optimal energy conversion characteristics.

Abstract: A micromini condenser microphone having a flexure hinge-shaped upper diaphragm and a back plate, and a method of manufacturing the same are provided.

Abstract: Disclosed is a high directive ultrasonic transducer that can concentrate a radiated ultrasonic wave in one direction by making an orientation angle of the radiated ultrasonic wave small in an ultrasonic transducer having a planar radiation plate structure, which has high radiation efficiency in an air medium. The high directive ultrasonic transducer according to the present disclosure includes a planar radiation plate configured to radiate an ultrasonic wave into a medium; a driving unit configured to vibrate the radiation plate in a higher order mode of a secondary order or more by applying predetermined force to a bottom surface of the radiation plate; and a matching layer formed in a height corresponding to 1/4 of an ultrasonic wavelength in the medium, in a part having a positive vibration velocity on a top surface of the radiation plate.

Abstract: In a piezoelectric speaker, an acoustic diaphragm is thicker than a piezoelectric thin film and is formed of a more flexible and higher elasticity material than the piezoelectric thin film, thereby greatly improving output sound pressure in a low frequency band and reducing sound distortion. Further, the piezoelectric thin film is attached to the acoustic diaphragm in an inclined structure in which the piezoelectric thin film is horizontally turned from the acoustic diaphragm, thereby preventing a standing wave from being created by structural symmetry and minimizing sound distortion.

Abstract: Sound can be listened to only in a listening area by maximizing a sound energy difference between a listening area and a non-listening area while maximizing sound radiation efficiency of each sound source. Accordingly, realistic sound can be provided to listeners without causing auditory disturbance to third parties, and maximal sound effects can be obtained with only minimal control.

Abstract: Disclosed is a system of transferring wireless power using an ultrasonic wave, including: an ultrasonic wave generating device converting and transferring electric energy to an ultrasonic wave; and an ultrasonic wave receiving device receiving the ultrasonic wave to convert the ultrasonic wave to electric energy, wherein the ultrasonic wave generating device includes a radiation plate with a plurality of ultrasonic elements and controls an effective area of the radiation plate by turning on/off the plurality of ultrasonic elements so that the ultrasonic wave receiving device is disposed at a position minimizing dispersion effect due to a circular radiation of the ultrasonic wave.

Abstract: Disclosed is a security monitoring method determining whether a trespasser is detected and a position of the trespasser in a set security space and monitoring sound generated at the position of the trespasser by using an acoustic image generated from acoustic signals generated by an acoustic generating device and an acoustic measuring device in an array type. An exemplary embodiment of the present disclosure provides a security monitoring system including: an acoustic generating device that generates acoustic signals; a plurality of acoustic measuring devices that receive the acoustic signals; and an acoustic image processing device that generates an acoustic image using a beamforming algorithm from the acoustic signals received in the plurality of acoustic measuring devices and determines a position of a trespasser by comparing the acoustic image after the trespasser is detected with the acoustic image before the trespasser is detected.

Abstract: Disclosed are a method for measuring a acoustic transfer function of a predetermined space to be secured or monitored through a correlation between sound signals acquired from a sound source generating device and a sound measuring device and a method and a system for judging whether there is an intrusion object by using a difference between an initially set acoustic transfer function information and varied acoustic transfer function information by using the method for measuring the transfer function. In the present disclosure, when an object moves or an intrusion object is generated in a predetermined space, intrusion or no intrusion is monitored by variation of the acoustic transfer function varied by the intrusion object even though there is no noise generated by the intrusion object.

Abstract: A piezoelectric microphone, a speaker, a microphone-speaker integrated device and a manufacturing method thereof are provided. The microphone-speaker integrated device includes a silicon substrate and an insulating layer deposited on the silicon substrate; a piezoelectric plate formed on the insulating layer; and a mating electrode formed on the piezoelectric plate. The mating electrode is patterned with a polarity arrayed in series.

Abstract: Provided is a forced acoustic dipole capable of regulating phases and acoustic pressures of first and second acoustic signals output from first and second pole speakers to freely steer the direction of an acoustic lobe. In addition, a forced acoustic multipole array is constituted by a plurality of forced acoustic dipoles. When the phases and acoustic pressures of the first and second acoustic signals output from the forced acoustic dipoles are regulated to steer an acoustic lobe in a specific direction, sound can be heard from a desired direction only without disturbing others.

Abstract: Provided is an active piezoelectric energy harvester, which can control a direct current voltage applied to an embedded variable capacitance layer to precisely adjust a resonance frequency in real time, and thus achieve a simpler structure and a smaller size compared to a conventional one that adjusts the resonance frequency using a separate variable capacitor provided outside. Further, the active piezoelectric energy harvester can precisely adjust the resonance frequency even when the frequency of vibration varies over time as in a real natural vibration environment or when it is degraded to undergo a variation in its own resonance frequency, and thus can continuously maintain optimal energy conversion characteristics.

Abstract: A security system and a method of determining whether there is an intrusion are provided. A correlation between sound signals obtained from a sound source generating device and a sound-field variation measuring device is used to measure a acoustic field in a certain space. A difference between an initially set acoustic field and a changed acoustic field is used to determine whether there is an intruding object in a certain space. The security system includes a sound source generating device for generating a sound source; and a sound-field variation measuring device for measuring a acoustic field formed by the sound source, wherein an initially set acoustic field is compared with the measured acoustic field to determine whether there is an intrusion.

Abstract: In a folding-type directional speaker array module, when sound is output, the directionality of a high frequency band can be obtained through a center speaker module and the directionality of a low frequency band can be obtained through side speaker modules unfolded from both sides of the center speaker module. Accordingly, the speaker array module has excellent directionality in an entire frequency band. Furthermore, the folding-type directional speaker array module has high mobility and portability because the side speaker modules are folded and stored when the folding-type directional speaker array module is not used.

Abstract: In a piezoelectric speaker, an acoustic diaphragm is thicker than a piezoelectric thin film and is formed of a more flexible and higher elasticity material than the piezoelectric thin film, thereby greatly improving output sound pressure in a low frequency band and reducing sound distortion. Further, the piezoelectric thin film is attached to the acoustic diaphragm in an inclined structure in which the piezoelectric thin film is horizontally turned from the acoustic diaphragm, thereby preventing a standing wave from being created by structural symmetry and minimizing sound distortion.

Abstract: Provided is near-field optical probe including: a cantilever arm support portion that is formed of a lower silicon layer of a silicon-on-insulator (SOI) substrate, the cantilever arm support portion having a through hole formed therein at a side of the lower silicon layer; and a cantilever arm forming of a junction oxidation layer pattern and an upper silicon layer pattern on the SOI substrate that are supported on an upper surface of the lower silicon layer and each have a smaller hole than the through hole, a silicon oxidation layer pattern having a tip including an aperture at a vertical end, corresponding with the hole on the upper silicon layer pattern, and an optical transmission prevention layer that is formed on the silicon oxidation layer pattern and does not cover the aperture.

Abstract: A piezoelectric microspeaker using microelectromechanical systems (MEMS) and a method of manufacturing the same are provided. The piezoelectric microspeaker includes a piezoelectric layer disposed on an elastic thin layer, and a resonance change unit patterned on one of a bottom surface of the elastic thin layer and a top surface of the piezoelectric layer.

Abstract: Provided are an acoustic multi-pole array and methods of packaging and controlling the same. The methods include packaging first and second sound devices constituting an acoustic multi-pole array to have different sound characteristics or the same sound characteristic, arranging the first and second sound devices in tandem, and then respectively inputting sound sources having the same magnitude and different phases to the first and second sound devices to improve forward directivity and reduce a backward radiation characteristic.

Abstract: Provided is a small form factor optical/magnetic disk including an integrated metal hub and a disk plate. The integrated metal hub includes a circular upper metal hub and a circular lower metal hub integrally formed with and disposed under the upper metal hub. The circular lower metal hub has a smaller diameter smaller than the upper metal hub. A central hole is formed in central portions of the upper and lower metal hubs and passes through the upper and lower metal hubs. The disk plate has a through-hole that is formed in a central portion and is directly associated with the integrated metal hub, and a recess that is formed around the through-hole and allows the upper metal hub to be mounted therein. Since the central portion of the small form factor optical/magnetic disk is not thick, the small form factor optical/magnetic disk can contribute to an ultra thin small form factor information storage device. Also, since manufacturing processes are simple, price and quality competitiveness can be enhanced.