Abstract: Disclosed herein is an untact DC electric-field sensor having improved sensitivity. The untact DC electric-field sensor has a circuit composed of a variable capacitor and an RF generator and improves sensitivity through resonance of the circuit by connecting an inductor to the sensor.

Abstract: A verifiable credential verifying apparatus and method are disclosed. The verifiable credential verifying method of the verifiable credential verifying apparatus, according to an embodiment of the present disclosure, comprises the steps of receiving, by the verifiable credential verifying apparatus, a verifiable credential verification request for receiving approval of using a service provided by a service provider from a first terminal of a service user, verifying verifiable credential of the first terminal by using first verifiable credential of the first terminal, which has been received according to the verifiable credential verification request, and second verifiable credential pre-registered by the first terminal in the verifiable credential verifying apparatus; and transmitting a result of verifying the verifiable credential of the first terminal to the first terminal and a second terminal of the service provider.

Abstract: Provided is a metamaterial-based polarization converter in which a reception antenna and a transmission antenna are formed by using a metamaterial, to thus emit an incident non-polarized or polarized electromagnetic wave in an angle-converted polarization direction. The metamaterial-based electromagnetic wave polarization converter includes: a reception antenna made of a metamaterial and allowing incident electromagnetic waves to resonate at a surface of the reception antenna to generate a surface current; a transmission antenna at a rear side of the reception antenna, and made of an angle-converted metamaterial to thus allow the electromagnetic waves transferred from the reception antenna to resonate to then be emitted in a polarization direction; and a connector made of a conductive material that connects the reception antenna and the transmission antenna, to thereby transfer a surface current generated from the reception antenna to the transmission antenna.

Abstract: Provided is a metamaterial-based polarization converter in which a reception antenna and a transmission antenna are formed by using a metamaterial, to thus emit an incident non-polarized or polarized electromagnetic wave in an angle-converted polarization direction. The metamaterial-based electromagnetic wave polarization converter includes: a reception antenna made of a metamaterial and allowing incident electromagnetic waves to resonate at a surface of the reception antenna to generate a surface current; a transmission antenna at a rear side of the reception antenna, and made of an angle-converted metamaterial to thus allow the electromagnetic waves transferred from the reception antenna to resonate to then be emitted in a polarization direction; and a connector made of a conductive material that connects the reception antenna and the transmission antenna, to thereby transfer a surface current generated from the reception antenna to the transmission antenna.