Abstract: The present invention is directed to a method of changing a transmission mode, a method of requesting a packet retransmission, and a method of retransmitting a packet with respect to a broadcasting or multicast service. According to the invention, a plurality of terminals provided with one broadcasting or multicast service shares one random access channel (RACH) so as to transmit channel information. Accordingly, a base station receives the channel information through one RACH from the terminal or detects a packet collision generated in the RACH to confirm a request for changing the transmission mode or a request for maintaining the transmission mode by the terminal.

Abstract: The present invention relates to dielectric ceramic compositions for microwave applications consisting of BaO, PbO, Nd.sub.2 O.sub.3, CeO.sub.2, La.sub.2 O.sub.3 and TiO.sub.2 or consisting of compositions including these elements and having a composition formula (I).x(Ba.sub.1-.alpha. Pb.sub..alpha.)O-y?Nd.sub.2 O.sub.3(1-.beta.-.gamma.) CeO.sub.2(.beta.) La.sub.2 O.sub.3(.gamma.) !-zTiO.sub.2 (I)wherein mol %, 6.ltoreq.x.ltoreq.20, 10.ltoreq.y.ltoreq.20, 60.ltoreq.z.ltoreq.75, x+y+z=100; and 0<.alpha..ltoreq.0.5, 0.ltoreq..beta..ltoreq.0.2, 0.ltoreq..gamma..ltoreq.0.2 and 0<1-.beta.-.gamma.<1. These dielectric ceramic compositions for microwave applications have a dielectric constant above 90 at room temperature, a temperature coefficient at the resonant frequency within +5 ppm/.degree.C.

Abstract: The present invention relates to a manufacturing method of a polymer GRIN lens which is used for focusing light in connections for example between two or more optical fibers and between an optical fiber and a light source in the optical communication field. The manufacturing method of a GRIN lens according to the present invention utilizes a characteristic of polystyrene that its refractive-index is decreased by sulfonation. The method includes polymerizing a sphere or rod made of a directional monomer that is capable of sulfonating like a styrene, together with a cross-linking agent, and a polymerization initiator; swelling the polymerized cross-linked polymer by using a predetermined solvent; and sulfonating the swollen cross-linked polymer using a sulfuric acid. Accordingly, the present method can be easily controlled to obtain the desired refractive-index distribution since the refractive-index distribution is determined by the diffusion of the sulfuric acid as a sulfonation.

Abstract: An optical waveguide intensity modulator of a polymer waveguide utilizes and electro-optic effect and optical birefringence induced from a poling process of a nonlinear polymer thin-film. The optical waveguide intensity modulator is constructed by a series combination of a TE/TM mode selector, a TE or TM mode converter and another TE or TM mode selector. In the polymer waveguide, the mode selectors and mode converter can be easily obtained by making the direction of a poling field to be horizontal (or vertical) and approximately 45.degree. direction. According to the present invention, the optical waveguide intensity modulator is formed by integrating the TE or TM mode selectors and the TE or TM mode converter onto a single substrate. Further, because no element, is required which results in optical loses for example an optical isolator, an optical coupler or a curved portion of the waveguide, the efficiency of the device can be improved.

Abstract: A micro light valve which is corresponding to each of pixels for display and which passes or shuts a light beam by electrostatic force to display images, said light valve comprising a data electrode formed on a substrate and connected with each of data lines through a via; a selection electrode formed on the substrate and connected with each of selection lines; a common electrode formed between the selection and data electrodes; a flat-shaped micro shifting element capable of moving in linear direction and which serves as a resistance body; insulating layers formed respectively between the shifting element and each of the electrodes; a frame for serving as a black matrix, which has a guiding means for guiding the shifting element; and the three electrodes for receiving externally applied driving signals to drive the shifting element and which serve as stationary elements with three phases.

Abstract: A bidirectional multi-channel all-optical ring network is provided, this network comprising a number of nodes linked by optical cables, each of the node comprising two of WDM/WDDM, packet switching devices, and a node controller, in which network a first optical signal group of wavelength channel signals (for example, .lambda.1, .lambda.3, .lambda.5, . . . ) are transferred in a counter-clockwise direction, and a second optical signal group of wavelength channel signals (for example, .lambda.2, .lambda.4, .lambda.6, . . .) are transferred in a clockwise direction, thereby allowing an optical data signal to be transmitted through the channel of shorter distance.

Abstract: The present invention relates to a photomask for forming a T-shaped gate structure on a high speed FET through a photolithography, comprising opaque layer patterns 2 and 2a for defining a head portion of the T-shaped gate structure and half-tone layer patterns 3 and 3a for defining a foot portion thereof.The half-tone film patterns composed of a chrome layer are deposited to a thickness thinner than that of the opaque layer patterns so that the half-tone layer patterns show a relatively lower transmittance to an incident beam.The application of the photomask of the invention to the process for forming a T-shaped gate structure improves process reproducibility and leads to great cost savings.

Abstract: Unwanted distortion of the planar configuration of a carbon-based X-ray lithography mask, that would otherwise occur during selective etching of the (silicon) support substrate, is prevented by incorporating a compensation layer of inorganic material that effectively offsets the internal compressive stress characteristic of the carbon. For this purpose, on a top, planar surface of a silicon substrate, a multiple layer structure containing a first layer of carbon having an internal compressive stress characteristic and a second layer of inorganic material having an internal tensile stress characteristic, is plasma-deposited. The tensile stress characteristic of the inorganic layer compensates for the compressive stress characteristic of the carbon layer and causes the composite structure to retain its substantially planar configuration after the underlying silicon substrate has been etched in the course of obtaining a rim structure on which the X-ray transmissive structure is supported.