Abstract: An acoustic tweezer is disclosed. The acoustic tweezer includes a function signal generator configured to generate a function signal for an ultrasound signal, a power amplifier configured to amplify the ultrasound signal based on the function signal, and an ultrasound transducer of a single channel in which a hologram thin film having different thin film thicknesses for each region is attached to an ultrasound oscillating surface of the ultrasound transducer, and the ultrasound transducer is configured to generate a plurality of ultrasound signals having different phase differences by allowing an oscillated ultrasound signal to pass through the hologram thin film.

Abstract: An electroluminescent display device includes an electroluminescent display device includes a substrate; a first pixel row on the substrate including a first plurality of pixels arranged along a first direction; a second pixel row on the substrate including a second plurality of pixels arranged along the first direction, the second pixel row being spaced apart from the first pixel row in a second direction; a first groove between the first and second pixel rows; and a light emitting diode in each pixel of the first and second pixel rows, wherein the first groove includes a first portion at one end of the first pixel row, a second portion at the other end of the first pixel row and a third portion between the first and second portions, and wherein third portion is smaller than the first portion and greater than the second portion.

Abstract: A pseudo dual port memory device in which an operating speed is improved and stability is increased is provided. The pseudo dual port memory device may include a memory cell, a pair of bit lines connected to the memory cell, a write driver, a sense amp, and a column multiplexer which is connected to the bit lines, receives a write multiplexer control signal and a read multiplexer control signal, connects the bit lines to the write driver in response to the write multiplexer control signal, and connects the bit lines to the sense amp in response to the read multiplexer control signal. A precharge control signal generation circuit which is connected to the column multiplexer may generate a precharge control signal on the basis of the read and write multiplexer control signals, and a bit line precharge circuit may precharge the bit lines based on the precharge control signal.

Abstract: Disclosed are a system and method of issuing a key for a door lock at lodging facilities using a smart phone, wherein the system includes: a guest smart phone that makes a request for a reservation and payment at lodging facilities; a door-lock key issuing server that is requested to make a reservation and payment from the guest smart phone, acts as a proxy to make the reservation and payment at the lodging facilities; and a lodging-facilities server that approves the reservation and payment made by the door-lock key issuing server, receives the password of the key for the door lock from the door-lock key issuing server, approves the smart phone when accessed by the smart phone, and permits the door to be open by the Bluetooth communication with the approved smart phone.