Electronics and Telecommunications Research Institute

Gwangju Institute of Science and Technology

San Diego State University Research Foundation

Mokpo National Maritime University Industry-Academic Cooperation Foundation

Gunn Hwang

Sung Q Lee

Chang Auck Choi

Chang Han Je

Myung Lae Lee

WooSub Youm

Sung Sik Lee

Sung Hae Jung

Seok Hwan Moon

Woo Seok Yang

Chang-Auck Choi

Myung-Lae Lee

Sung-Hae Jung

Chang-Han Je

Jong Hyun Lee

Sung Weon Kang

Youn Tae Kim

Ji Man Park

Jongdae Kim

Yusuf Ozturk

Tae Goo Choy

Seok-Hwan Moon

Kee Moon

Chang-Kyu Kim

Hyung Kun Lee

Ho Gyeong Yun

Sung Sik Yun

Joho Yun

Dae Hun Jeong

Jae Yong An

Joong Moo Park

Sang-Hoon Kim

Jung-Woo Kim

Provided are an acoustic Luneburg meta lens including a lens structure on the substrate or a lens structure connected to each other by connecting rods, wherein the lens structure includes a plurality of unit structures, the volume of the unit structures decreases from the center of the lens structure toward an edge thereof, and positions of the unit structures are determined by direction components of a polar coordinate system or a spherical coordinate system, and a method for designing the acoustic Luneburg meta lens.

Acoustic Luneburg meta lens and design method thereof

Disclosed is a method of operating a flow sensor according to an embodiment of the present disclosure, which includes receiving an ultrasonic signal reflected from a particle, generating first and second digital, generating a first Doppler frequency based on the first and second digital signals, a predetermined number of samples, and a first time period, comparing the first Doppler frequency with a second reference frequency, when the first Doppler frequency is less than a first reference frequency, down-sampling the predetermined number of samples to a first sampling frequency or a second sampling frequency, generating a second Doppler frequency based on the first and second digital signals, the number of down-sampled samples, and a second time period determining an output frequency based on the second Doppler frequency when the first Doppler frequency is less than a first reference frequency, and obtaining flow information of the particle based on the output frequency.

Flow sensor performing multi level down sampling and method thereof

The present invention relates to a fluorescence sensor for measuring microalgae and a method of operating the same. The fluorescence sensor for measuring the microalgae includes a fluorescence measurement unit including a light emitter configured to irradiate excitation light onto a measurement region and a detector configured to measure fluorescence emitted from the measurement region, an algae control unit configured to form a node and an antinode of an ultrasonic standing wave in the measurement region to control an algal density, and a signal processing unit configured to calculate the algal density using fluorescence intensity signals according to an operation mode of the algae control unit.

Fluorescence sensor for measuring microalgae and method of operating the same

The circuit for measuring a bio-stimulating and bio-signal according to an embodiment of the inventive concept may include a bio-stimulating signal generating circuit, a bio-signal electrode, a switch block, first and second resistors, and a bio-signal measuring circuit. The bio-stimulating signal generating circuit may generate a bio-stimulating signal in a bio-stimulating mode. The bio-signal electrode may to deliver the bio-stimulating signal generated in the bio-stimulating mode and receive a bio-signal in a bio-signal measuring mode. The switch block may be turned on in a case where a voltage of the bio-stimulating signal is greater than a first reference voltage or lower than a second reference voltage. The first and second resistors may be serially connected between the bio-signal electrode and the switch block and divide a voltage of a signal of the bio-signal electrode according to whether the switch block is turned on. The bio-signal measuring circuit may measure voltage signals divided by the first and second resistors or measure a signal of the bio-signal electrode, according to whether the switch block is turned on. The first reference voltage may be greater than the second reference voltage.

Bio-stimulating and bio-signal measuring circuit

A device and method is described for electronic human prosthetics, and specifically a skull- and/or spine implantable bi-directional neural-communication/brain-machine interface (BBMI) device where the input, output and on-board computing are combined into a single unit to form a compact neuro-prosthetics device. This invention is also directed to a fully implantable wireless spinal electronic recording and stimulation system using the BBMI in a human. The bi-directional devices (BBMIs) communicate with other bi-directional brain-machine interface devices (BBMI) and/or with external controllers wirelessly. The compact implantable stimulator has ultrasonic secondary battery charging system. One or more BBMI can be wirelessly connected so that a closed loop of BBMIs, or a BBMI and an external controller, can wirelessly send trigger pulses to this fully implanted stimulator over the spinal cord.

Apparatus and method of implantable bidirectional wireless neural recording and stimulation

The circuit may include bio-stimulating signal generating circuit which generates a bio-stimulating signal in a bio-stimulating mode, a bio-signal electrode which delivers the bio-stimulating signal generated in the bio-stimulating mode and receives a bio-signal in a bio-signal measuring mode, a switch block which is turned on when a voltage of the bio-stimulating signal is greater than a first reference voltage which is greater than a second reference voltage or lower than the second reference voltage, first and second resistors, and a bio-signal measuring circuit which measures voltage signals divided by the first and second resistors or measures a signal of the bio-signal electrode according to whether the switch block is turned on. The first and second resistors may be serially connected between the bio-signal electrode and the switch block, and divide a voltage of a signal of the bio-signal electrode when the switch block is turned on.

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.

Device for detecting change in underground medium

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.

Wireless power transmission system calculating the battery charge state of the receiver based on the supply impedance of the power source and the summed impedance of the wireless transmitter, wireless receiver, medium therebetween, and battery charge circuit

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.

Wireless power transmission apparatus using ultrasound

Disclosed are ultrasonic wireless power transmitter and receiver apparatuses, and a method for wireless charging thereof. A method for wireless charging according to the present disclosure includes: transmitting, by an ultrasonic wireless power transmitter apparatus, an wakeup signal to an ultrasonic wireless power receiver apparatus; calculating, by the ultrasonic wireless power transmitter apparatus, a charging time according to a charging status information received from the ultrasonic wireless power receiver apparatus; generating, by the ultrasonic wireless power transmitter apparatus, an ultrasonic signal, amplifying the generated ultrasonic signal to predetermined voltage and thereafter; charging, by the ultrasonic wireless power transmitter apparatus, the ultrasonic wireless power receiver apparatus for the calculated time and thereafter; and determining, by the ultrasonic wireless power transmitter apparatus, whether secondary charging is to be performed according to a charged status information received from the ultrasonic wireless power receiver apparatus.

Ultrasonic wireless power transmitter and receiver apparatuses, and method for wireless charging thereof

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.

Charging device with piezoelectric-composite and ultrasonic apparatus with the same

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.

System for transferring wireless power using ultrasonic wave

There is provided a high resolution circuit for converting a capacitance-to-time deviation including a capacitance deviation detecting unit generating two detection signals having a phase difference corresponding to variations of capacitance of an micro electro mechanical system (MEMS) sensor; a capacitance deviation amplifying unit dividing frequencies of the two detection signals to amplify the phase difference corresponding to the capacitance deviation; and a time signal generating unit generating a time signal having a pulse width corresponding to the amplified phase difference.

High resolution circuit for converting capacitance-to-time deviation

An apparatus for preventing stiction of a three-dimensional MEMS (microelectromechanical system) microstructure, the apparatus including: a substrate; and a plurality of micro projections formed on a top surface of the substrate with a predetermined height in such a way that a cleaning solution flowing out from the microstructure disposed thereabove is discharged.

Apparatus for preventing stiction of MEMS microstructure

There is provided a flat plate type micro heat transport device formed of two plates coupled with each other to be opposite to each other, each of the plates includes: a reservoir formed to store a moving fluid charged via an inlet; a evaporator formed separated from the reservoir to generate vapor having latent heat by vaporizing the moving fluid; a vapor flow path formed to be connected to the evaporator, through which the vapor having latent heat is transported; a condenser formed to be connected to the vapor flow path and to condense the vapor having latent heat; and a liquid flow path formed to be connected to the condenser and the evaporator and separately from the vapor flow path to transport a liquid obtained by condensing the vapor. The device may efficiently control heat with respect to portable electronic devices by effectively transporting heat generated by a heat source.

Growing community of inventors

Seoul, South Korea

Gunn Hwang