Abstract: A positive electrode active material for a lithium secondary battery has secondary micro particles having an average particle size (D50) of 1 to 10 ?m formed by agglomeration of primary macro particles having an average particle size (D50) of 0.5 to 3 ?m and a lithium-M oxide coating layer on all or part of a surface, wherein M is at least one selected from the group consisting of boron, cobalt, manganese and magnesium. The secondary macro particles have an average particle size (D50) of 5 to 20 ?m formed by agglomeration of primary micro particles having a smaller average particle size (D50) than the primary macro particles. The primary macro particles and the primary micro particles are represented by LiaNi1?b?c?dCobMncQdO2+?, wherein 1.0?a?1.5, 0<b<0.2, 0<c<0.2, 0?d?0.1, 0<b+c+d?0.2, ?0.1???1.0, and Q is at least one type of metal selected from the group consisting of Al, Mg, V, Ti and Zr.

Abstract: A wheel resonator for reducing a resonance phenomenon inside a tire of a vehicle may include a plurality of wheel resonators mounted to a tire wheel. First and second wheel resonators of the plurality of wheel resonators are fixed with each other by a fastening part including a protrusion disposed on an end of the first wheel resonator penetrating through a hole disposed in an end of the second wheel resonator. An end portion of the protrusion has a size greater than a size of the hole. As such, quality of a wheel through more reliable noise reduction by making a wheel resonator in a manner of forming a fitting type fastening part in the wheel resonator itself and fixing the wheel resonator by ultrasonic welding can be improved.

Abstract: A wheel resonator for reducing a resonance phenomenon inside a tire of a vehicle may include a plurality of wheel resonators mounted to a tire wheel. First and second wheel resonators of the plurality of wheel resonators are fixed with each other by a fastening part including a protrusion disposed on an end of the first wheel resonator penetrating through a hole disposed in an end of the second wheel resonator. An end portion of the protrusion has a size greater than a size of the hole. As such, quality of a wheel through more reliable noise reduction by making a wheel resonator in a manner of forming a fitting type fastening part in the wheel resonator itself and fixing the wheel resonator by ultrasonic welding can be improved.

Abstract: The present invention relates to a terahertz wave modulator. The terahertz wave modulator includes: a semiconductor substrate; a terahertz modulation layer including an organic-material layer disposed on the semiconductor substrate; and a first incident wave radiation unit for vertically radiating a first incident wave having a terahertz wave region onto the terahertz modulation layer. The transmitted terahertz wave may be variously modified according to the degree of crystallization of an organic material deposited on the semiconductor substrate and according to the intensity of incident light so as to maximize modulation efficiency using the modified terahertz wave. Thus, a device for modulating wavelength width, amplitude, and phase through waveform deformation in a time region may be provided.

Abstract: The present invention relates to a terahertz wave modulator. The terahertz wave modulator includes: a semiconductor substrate; a terahertz modulation layer including an organic-material layer disposed on the semiconductor substrate; and a first incident wave radiation unit for vertically radiating a first incident wave having a terahertz wave region onto the terahertz modulation layer. The transmitted terahertz wave may be variously modified according to the degree of crystallization of an organic material deposited on the semiconductor substrate and according to the intensity of incident light so as to maximize modulation efficiency using the modified terahertz wave. Thus, a device for modulating wavelength width, amplitude, and phase through waveform deformation in a time region may be provided.

Abstract: A filter having a high transmittance. The filter includes a substrate having a first surface and a second surface, and a periodic or random array of through-holes formed so as to pass through the first surface and the second surface. The through-hole has a size of subwavelength at a range of infrared and terahertz wave. Here, transmission resonance characteristic of incident light on the first surface is controlled by a shape of the through-hole.