Abstract: Provided is a security surveillance system and method capable of separately detecting fire and intrusion situations on the basis of a sound field variation, including a sound generating device outputting, into a set security surveillance space, a multi-tone sound wave formed of a linear sum of sine waves having a plurality of frequency components, a sound receiving device obtaining sound field information for each frequency represented as sound pressure and a phase from a sound wave received in the security surveillance space, and a sound field signal processing device storing sound field information for each frequency obtained from the sound receiving device in a preparation mode, comparing the stored sound field information with current sound field information for each frequency output from the sound receiving device in a surveillance mode, and determining occurrence of a security situation.

Abstract: A gas monitoring apparatus according to the inventive concept includes a sound generator, a sound receiver, and a sound field signal processor. The sound generator continuously outputs a sound signal into a gas monitoring space. The sound receiver receives a sound signal reflected from the gas monitoring space. The sound field signal processor obtains sound field information on the received sound signal, calculates a sound field spectrum for the sound field information, uses a correlation between the calculated sound field spectrum and a reference sound field spectrum, and determines whether there are gas leak and mixing in the gas monitoring space, wherein the reference sound field spectrum is a sound field spectrum according to frequency measured in a case where a gas is not leaked in the gas monitoring space, and the sound signal is formed by a linear sum of sine waves that have a plurality of frequency components.

Abstract: Provided is a wireless power transmission apparatus. The apparatus includes an ultrasound transmitter generating an ultrasound signal in response to an external source voltage and transmitting the generated ultrasound signal to a medium layer and an ultrasound receiver receiving the ultrasound signal through the medium layer and converting the received ultrasound signal into a driving voltage. The ultrasound transmitter and receiver are manufactured to control impedance values thereof to be matched with each other and a distance between the ultrasound transmitter and receiver is controlled according to predetermined distance conditions.

Abstract: The inventive concept relates to a device that detects a leak of a liquid leaked from a sinkhole, water pipe or oil pipeline under the ground. In the detection device of the inventive concept, a plurality of reception devices disposed on the surface of the earth simultaneously receive an ultrasonic signal transmitted from a transmission device under the ground and a radio frequency (RF) signal synchronized with the ultrasonic signal. Also, by measuring an arrival time of the ultrasonic signal by using the wireless signal received by each reception device as a triggering signal, a leak range of a liquid leaked from a sinkhole, water pipe or oil pipeline on a signal path between the transmission device and the reception device is detected.

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

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 method of manufacturing a piezoelectric speaker comprises forming a piezoelectric thin film and then forming an upper electrode and a lower electrode on and beneath the piezoelectric thin film, respectively, forming a damping material layer for attachment of the piezoelectric thin film below the piezoelectric thin film with the upper and lower electrodes formed thereon and therebeneath, attaching the piezoelectric thin film to an acoustic diaphragm in an inclined structure in which the piezoelectric thin film is horizontally turned from the acoustic diaphragm, and performing drying at room temperature; and fixing the acoustic diaphragm to a frame using an adhesive material with high elasticity.

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 a security monitoring method including outputting a multi-tone sound wave configured with a linear sum of sine waves having a plurality of frequency components inside a security monitoring space, receiving the multi-tone sound wave and calculating a sound field, calculating and storing sound field information according to frequency through the sound field, comparing reference sound field information according to frequency with the currently measured sound field information and determining whether a sound field variation occurs, and analyzing whether the sound field variation occurs collected for a certain predetermined period and distinguishing at least two events among intrusion, motion and temperature variation situations on the basis of correlation between the reference sound field spectrum and consecutive sound field spectra.

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: Provided is an ultrasonic apparatus. The ultrasonic apparatus may include a charging device, a circuit device electrically connected to the charging device, and a housing part for packaging the charging device and the circuit device. Here, the charging device may include a lower electrode, an upper electrode provided on the lower electrode, a plurality of pillar-shaped piezoelectric composites provided between the lower and upper electrodes, and an electrolyte layer provided between the lower and upper electrodes to fill spaces between the pillar-shaped piezoelectric composites.

Abstract: Provided is a wireless power transmission system. The wireless power transmission system includes a power supply unit generating amplified power; a wireless power transmission unit receiving and converting the amplified power into wireless power; a wireless power reception unit receiving and converting the wireless power into charging power; and a charging unit receiving the charging power, wherein the charging unit includes a battery to store the charging power and the power supply unit includes a power detection unit identifies the charged state of the battery based on the amplified voltage and amplified current of the amplified power.

Abstract: Disclosed are a method and a system for monitoring a fire based on a detection of sound field variation. The system for monitoring a fire based on a detection of sound field variation includes: a sound generator outputting a sound wave within a defined space according to input voltage; a sound receiver receiving the sound wave within the defined space and obtaining a sound pressure from the received sound wave; and a fire monitor using a sound transfer function representing a ratio of the sound pressure obtained by the sound receiver to input voltage of the sound generator in a preparation mode to calculate reference sound pressure information, using the sound transfer function in a monitoring mode to calculate current sound pressure information, and comparing the reference sound pressure information with the current sound pressure information to determine whether a fire occurs.

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: Provided is a wireless power transmission apparatus. The apparatus includes an ultrasound transmitter generating an ultrasound signal in response to an external source voltage and transmitting the generated ultrasound signal to a medium layer and an ultrasound receiver receiving the ultrasound signal through the medium layer and converting the received ultrasound signal into a driving voltage. The ultrasound transmitter and receiver are manufactured to control impedance values thereof to be matched with each other and a distance between the ultrasound transmitter and receiver is controlled according to predetermined distance conditions.

Abstract: Provided is a security surveillance system and method capable of separately detecting fire and intrusion situations on the basis of a sound field variation, including a sound generating device outputting, into a set security surveillance space, a multi-tone sound wave formed of a linear sum of sine waves having a plurality of frequency components, a sound receiving device obtaining sound field information for each frequency represented as sound pressure and a phase from a sound wave received in the security surveillance space, and a sound field signal processing device storing sound field information for each frequency obtained from the sound receiving device in a preparation mode, comparing the stored sound field information with current sound field information for each frequency output from the sound receiving device in a surveillance mode, and determining occurrence of a security situation.

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: Provided is an ultrasonic apparatus. The ultrasonic apparatus may include a charging device, a circuit device electrically connected to the charging device, and a housing part for packaging the charging device and the circuit device. Here, the charging device may include a lower electrode, an upper electrode provided on the lower electrode, a plurality of pillar-shaped piezoelectric composites provided between the lower and upper electrodes, and an electrolyte layer provided between the lower and upper electrodes to fill spaces between the pillar-shaped piezoelectric composites.

Abstract: A piezoelectric speaker and a method of manufacturing the same that can obtain a high sound pressure using a piezoelectric thin film are provided. The piezoelectric speaker includes a piezoelectric thin film, electrodes formed on an upper surface or upper and lower surfaces of the piezoelectric thin film, a damping material layer formed on the lower surface of the piezoelectric thin film, and a frame attached around at least one of the piezoelectric thin film and the damping material layer using an adhesive.

Abstract: A condenser microphone having a flexure hinge diaphragm and a method of manufacturing the same are provided. The method includes the steps of: forming a lower silicon layer and a first insulating layer; forming an upper silicon layer on the first insulating layer; forming sound holes by patterning the upper silicon layer; forming a second insulating layer and a conductive layer on the upper silicon layer; forming a passivation layer on the conductive layer; forming a sacrificial layer on the passivation layer; depositing a diaphragm on the sacrificial layer, and forming air holes passing through the diaphragm; forming electrode pads on the passivation layer and a region of the diaphragm; and etching the layers to form an air gap between the diaphragm and the upper silicon layer. Consequently, a manufacturing process may improve the sensitivity and reduce the size of the condenser microphone.