Abstract: An electronic device having a heat dissipating component is provided. The electronic device includes a circuit board, a heat pipe which is disposed on a first side of the circuit board, a heat generating device which is disposed on a second side of the circuit board opposite to the first side, a heat sink placed which is disposed on a surface of the heat generating device and absorbs heat of the heat generating device, and a connecting member which penetrates through the circuit board and thermoconductively connects the heat pipe and the heat sink.

Abstract: A composite masking system and method for improving the invisibility of high-definition video watermarking. The composite masking system includes a watermark generation module, a mask generation module, and watermark embedment means. The watermark generation module generates a basic watermark pattern using a private key, and generate a watermark pattern by repeatedly extending the basic watermark pattern. The mask generation module generates a Noise Visibility Function (NVF) mask using NVF masking means, an adaptive dithering mask using adaptive dithering masking means, and a contour mask using contour masking means. The watermark embedment means generates a composite mask by multiplying the NVF mask, the adaptive dithering mask and the contour mask together, multiplying the composite mask and the extended watermark pattern together, and embedding the result of the second multiplication in the luminance channel of an original image.

Abstract: A method of compensating clock skew may include generating (2M+1) detected values by applying (2M+1) delay clock signals to (2M+1) pieces of delay data, wherein M is a natural number, determining a dominant logic value based on a comparison of a number of logic high detected values and a number of logic low detected values from among the (2M+1) detected values, determining a median delay time based on a number of the (2M+1) detected values having the dominant logic value, and adjusting a phase of a clock signal using the median delay time.

Abstract: An apparatus for passively cooling and retaining molten core material discharged from a damaged reactor vessel during a severe accident in the nuclear plant including: a molten core material retention tank to retain molten core material; a compressed gas tank storing high-pressure inert gas; a cooling water storage tank being installed higher than the molten core material retention tank; and a mixing means. The molten core material retention tank includes an outer retention vessel having at least one coolant hole, a porous protection vessel formed at an inside of the outer retention vessel, and a gravel layer formed between the outer retention vessel and the porous protection vessel. The apparatus can be installed in a reactor cavity without changing the compartment structure of a containment building, and makes it possible to prevent a steam explosion during the cooling process for the ultrahigh-temperature molten core material and to secure the reliability of the cooling process.

Abstract: A front photo detector (FPD) of an optical pick-up for an optical recording and playing apparatus having no gain selection switch, a simplified configuration, an improved prevention of an abnormal operation due to an error in gain selection, and improved reliability. The front photo detector includes a photo diode unit, a current-voltage amplifying circuit, and a voltage amplifying unit. The photo diode unit outputs current proportional to the power of the light emitted from one of a plurality of laser diodes. The current-voltage amplifying circuit converts the current output from the photo diode unit into a voltage. The voltage amplifying circuit amplifies the voltage output from the current-voltage amplifying circuit by a predetermined gain.

Abstract: A light guide plate and a liquid crystal display device having the same. The light guide plate is disposed upstream of a liquid crystal panel to refract light supplied through an edge thereof, toward the liquid crystal panel. In the light guide plate, a plate body is disposed at a side of a light source for supplying light when a supply voltage is applied. A plurality of pyramidal diffusing elements are arrayed in a predetermined pattern on a surface of the plate body. Each of the diffusing elements is rotated clockwise or counterclockwise about an axis extending through a vertex of the diffusing element perpendicularly to the surface of the plate body so that an edge of the diffusing element facing a reference line connecting a central point of the light source to a central point of the plate body is angled 10° to 35° about the reference line.

Abstract: The invention relates to a total internal reflection micro lens array for a wide-angle lighting system. The micro lens array includes a plurality of Fresnel lens structures formed on a same optical incidence surface. Each of the Fresnel lens structure includes a plurality of grooves, each having a reflecting surface and a refractive surface. Incoming radiation incident through the incidence surface of the lens structure is internally totally reflected by the reflecting surface, refracted by the refractive surface and exits the lens structure.

Abstract: An apparatus for passively cooling and retaining molten core material discharged from a damaged reactor vessel during a severe accident in the nuclear plant including: a molten core material retention tank to retain molten core material; a compressed gas tank storing high-pressure inert gas; a cooling water storage tank being installed higher than the molten core material retention tank; and a mixing means. The molten core material retention tank includes an outer retention vessel having at least one coolant hole, a porous protection vessel formed at an inside of the outer retention vessel, and a gravel layer formed between the outer retention vessel and the porous protection vessel. The apparatus can be installed in a reactor cavity without changing the compartment structure of a containment building, and makes it possible to prevent a steam explosion during the cooling process for the ultrahigh-temperature molten core material and to secure the reliability of the cooling process.

Abstract: An optical pickup used to record information on and/or reproduce information from an optical recording medium, the optical pickup including an optical module to emit a light beam; and a front photo-detector to monitor power of the light beam; wherein the optical module is coupled to the front photo-detector so that a fixed distance is maintained between the optical module and the front photo-detector.

Abstract: A method and apparatus for secure communication between a client and a server are provided. In the method, in order to enable communication between the client and the server, a session key is managed according to session identification information corresponding to the session key, and if there is a valid session key, data is encrypted or decrypted using the session key. If there is no valid session key, the client generates a new session key, operations for enabling application programs executed on one client to share a single session key are performed, so that secure communication is performed using the session key.

Abstract: Disclosed is an optical pickup device, which comprises a twin LD (Laser Diode) and an achromatic prism for compensating for optical axes, thereby omitting a separate optical component such as an HOE (Holographic Optical Element) or a wedge beam splitter and having a simple optical pickup structure. The optical pickup device includes a light emitting element for emitting two or more light beams having different wavelengths; an objective lens for converging the light beams emitted from the light emitting element onto an optical disk; a light receiving element for receiving light beams reflected by the optical disk; a beam splitter installed at an optical route between the light emitting element and the objective lens; and an achromatic prism installed at an optical route between the light emitting element and the beam splitter.

Abstract: A front photo detector (FPD) of an optical pick-up for an optical recording and playing apparatus having no gain selection switch, a simplified configuration, an improved prevention of an abnormal operation due to an error in gain selection, and improved reliability. The front photo detector includes a photo diode unit, a current-voltage amplifying circuit, and a voltage amplifying unit. The photo diode unit outputs current proportional to the power of the light emitted from one of a plurality of laser diodes. The current-voltage amplifying circuit converts the current output from the photo diode unit into a voltage. The voltage amplifying circuit amplifies the voltage output from the current-voltage amplifying circuit by a predetermined gain.

Abstract: An optical pickup used to record information on and/or reproduce information from an optical recording medium, the optical pickup including an optical module to emit a light beam; and a front photo-detector to monitor power of the light beam; wherein the optical module is coupled to the front photo-detector so that a fixed distance is maintained between the optical module and the front photo-detector.

Abstract: A memory system having a plurality of semiconductor memory devices includes a plurality of memory slots, a plurality of memory modules each having memory devices and being mounted on corresponding one of the memory slots, and a plurality of reference voltage sources for providing reference voltages each having a different level to the respective memory modules.

Abstract: A memory system having a plurality of semiconductor memory devices includes a plurality of memory slots, a plurality of memory modules each having memory devices and being mounted on corresponding one of the memory slots, and a plurality of reference voltage sources for providing reference voltages each having a different level to the respective memory modules.