Abstract: Disclosed is a VDSL (very high bit-rate digital subscriber line) system on the DMT line coding method basis and a method for determining a length of cyclic prefix samples using the system. The VDSL system comprises a transmitter data including cyclic prefix samples through a channel; a receiver for receiving the data including the cyclic prefix samples; a controller for controlling the transmitter and the receiver to control an initialization operation including handshake, training, channel analysis, and exchange, and a data transmission operation after the initialization operation; and a cyclic prefix sample length estimator for estimating an optimized length of the cyclic prefix sample on the basis of the correlation between the cyclic prefix sample and other data.

Abstract: The disclosure is an optical measuring system and the method thereof for precisely measuring physical characteristics of light emitted from waveguides, such as beam size, pattern, strength, focusing, collimation degree, and divergence angle, by means of a plane optical detector in which a plurality of pixels formed by a semiconductor fabrication process are arranged in an array, without specific measuring means. The light is incident into ends of the arrayed waveguides with uniform time intervals and emitted from the other ends of the waveguides to reach the optical detectors through which the physical characteristics of the light are obtained and defined arithmetically.

Abstract: A JAVA program language compile-on-demand service system and method for accelerating a processing speed of a JAVA program in a data processing system having a relatively low performance is provided. The JAVA COD service system compiles a JAVA class file to be executed in a data processing system into a pattern which can be executed more speedily on the data processing system, and then transmits the compiled result, upon a request of the data processing system connected via a network in order to execute the JAVA program at a relatively faster speed. The system includes JAVA program providing servers, data processing systems, and a compile-on-demand server for receiving a service request, downloading a requested JAVA class file, compiling the downloaded JAVA class file, and transmitting the compiled result.

Abstract: The present invention provides a method of improving the speed of processing of a system and optimizing system performance in RTOS by searching for a task on which occupancy time is the longest in a system mode and transferring a stack from an armored memory to an embedded memory, and by reallocating the stack pointers. According to the present invention, since a microprocessor which has an expensive and large embedded memory does not have to be mounted, costs of manufacturing in mass production can be lowered.

Abstract: The present invention relates to a high-frequency power amplifier having differential inputs, and more specifically to a high-frequency power amplifier having differential inputs, in which a structure of an output port of a communication system for 2.4 GHz ISM frequency band can be simplified by designing and producing the high-frequency power amplifier having differential inputs for 2.4 GHz ISM frequency band using a silicon germanium (SiGe) microwave monolithic integrated circuit (MMIC), thereby decreasing the number of components of a transmission unit and reducing a price of the communication system.

Abstract: The present invention relates to a dual-band omnidirectional antenna for wireless LANs. The antenna has a planar dielectric substrate, and first and second conductive patterns. The planar dielectric substrate has two parallel surfaces. The first conductive pattern is arranged on one surface of the substrate, and is provided with a first feeder line arranged on a longitudinal central line of the substrate and a plurality of radiating elements connected to the first feeder line and designed such that some of them operate in a high frequency band (4.9 to 5.85 GHz frequency band), and others thereof operate in a low frequency band (2.4 to 2.5 GHz frequency band).

Abstract: The present invention discloses a dual-band omnidirectional antenna for wireless LANs. The antenna has a planar dielectric substrate, and first and second conductive patterns. The planar dielectric substrate has two parallel surfaces. The first conductive pattern is arranged on one surface of the substrate, and is provided with a first feeder line arranged on a longitudinal central line of the substrate and a plurality of radiating elements connected to the first feeder line and designed such that some of them operate in a high frequency band (4.9 to 5.85 GHz frequency band), and others thereof operate in a low frequency band (2.4 to 2.5 GHz frequency band). The second conductive pattern is arranged on the other surface of the substrate, and provided with a second feeder line arranged on a longitudinal central line of the substrate and a plurality of radiating elements connected to the second feeder line and up-down symmetrically arranged with respect to the radiating elements on the first conductive pattern.

Abstract: A modular jack includes a housing, a first signal pair, and a second signal pair. The first signal pair passes through the housing and includes a first conductor and a second conductor. A first imaginary plane contains the first and the second conductor. The second signal pair passes through the housing and includes a third conductor and a fourth conductor. A second imaginary plane contains the third and the fourth conductor, which are bent at least one time to cross each other inside the housing. The first and the second imaginary plane form a first angle of 80 to 90 degrees inside the housing before the crossing of the third and the fourth conductor while they form a second angle of 0 to 10 degrees inside the housing after the crossing thereof.