Abstract: Disclosed is a multi-layered composite panel. The multi-layered composite panel comprises at least two sheets of thin plates with continuous waveform patterns having the same pitch and different heights in one direction are overlapped. In the multi-layered composite panel, an air layer is formed between the overlapping thin plates, orthogonal pressing portions, which divide the waveform patterns on the top and the bottom of the thin plates into the unit of triangle-patterned cell by being pressed orthogonally to cross each other on the top and the bottom of the thin plates overlapping in the orthogonal direction crossing the direction of the waveform patterns, are formed and an undercut portion is formed by pressing the centers of both sides connecting a groove and a ridge of each cell on the top and the bottom of the thin plates with opposite orthogonal pressing portions.

Abstract: Disclosed is an insulation fiber composite. In particular, a surface of the insulation fiber composite is substantially improved such that a shape of three dimensions can be maintained as a heat resisting fiber and an insulation material are integrated. The insulation fiber composite of the present invention has excellent formability and surface property and comprises an insulation layer; and a pair of inorganic fiber layers. A first inorganic fiber layer of the pair is stacked on an upper surface of the insulation layer and a second inorganic fiber layer is stacked on a lower surface of the insulation layer, respectively.

Abstract: A strength-reinforcing metal sheet having repetitive concave and convex features is provided. Concave beads extend in repetitive quadrangular lattice features. A plurality of convex cells are defined between the beads, protrude above the beads, and have repetitive convex features. The upper portion of each of the cells has a pyramidal shape similar to a dome. The uppermost point thereof is formed at an eccentric point offset from the central point of the cell.

Abstract: A strength-reinforcing metal sheet having repetitive concave and convex features is provided. Concave beads extend in repetitive quadrangular lattice features. A plurality of convex cells are defined between the beads, protrude above the beads, and have repetitive convex features. The upper portion of each of the cells has a pyramidal shape similar to a dome. The uppermost point thereof is formed at an eccentric point offset from the central point of the cell.

Abstract: Disclosed is a multi-layered composite panel. The multi-layered composite panel comprises at least two sheets of thin plates with continuous waveform patterns having the same pitch and different heights in one direction are overlapped. In the multi-layered composite panel, an air layer is formed between the overlapping thin plates, orthogonal pressing portions, which divide the waveform patterns on the top and the bottom of the thin plates into the unit of triangle-patterned cell by being pressed orthogonally to cross each other on the top and the bottom of the thin plates overlapping in the orthogonal direction crossing the direction of the waveform patterns, are formed and an undercut portion is formed by pressing the centers of both sides connecting a groove and a ridge of each cell on the top and the bottom of the thin plates with opposite orthogonal pressing portions.

Abstract: The present invention relates to a method for fabricating the plane waveguide path type of the heater buried optical switch, and it exposes the thin film heater removing the second clad layer to speed the heat radiation of the thin film heater by forming flatly the first clad layer having the thin thickness of about 5-10 .mu.m on the channel waveguide path on which the channel waveguide path is formed on the lower clad layer, and forming the second upper clad layer in the thickness of about 15-20 .mu.m on the first clad layer and the thin film heater after the thin heater having the line width of about two times as compared with these of the channel waveguide path is formed at the channel waveguide path and the corresponding portion on the first upper clad layer.