Abstract: A rake receiver for DS-CDMA UWB system and a DS-CDMA receiver having the same are provided. The rake receiver includes: a channel estimator for estimating a channel having a predetermined chip duration by using a synchronization acquisition sequence; a tracking module for detecting a channel variation and adjusting a synchronization position value when the channel variation is detected; a first switch for selecting one of an output value of an analog-to-digital converter and an output value of a correlator and outputting the selected value; a second switch for selecting one of the output value of the analog-to-digital converter and the output value of the correlator; and a plurality of demodulators having a parallel processing structure to demodulate received signals by using the channel estimation value inputted from the channel estimator, the synchronization position value stored by the tracking module, and an output value of the second switch.

Abstract: A method and apparatus for compensating for phase errors of a digital signal are provided. An equalizer compensates for an amplitude distortion of a received signal caused by a channel and outputs an equalized signal after a first predetermined delay time elapses. A first multiplying means complex multiplies the equalized signal by a phase corrected signal and outputs a first multiplied value. A first multiplexing means selectively outputs either the received signal or the first multiplied value based upon whether the first predetermined time has elapsed. A phase compensating means sets an initial value of a local oscillator based upon an average value of phase errors of the received signal before the first predetermined time elapses, and removes phase errors existing in the first multiplied value after the first predetermined time elapses.

Abstract: This invention relates to an outline font, and more particularly to a progressive renderable outline font and methods for transforming and rendering the same. Its purpose lies in supplying a progressively renderable Font which can be varied according to the quantity of the data composing the font. The Progressively Renderable Font has the function of controlling the display speed and the quality of the font. For example, if the hardware speed is relatively slow and a high quality font is not needed, only a part of the font data will be transmitted and displayed. On the contrary, if the hardware speed is relatively fast and high quality font is needed, gradually increased data will be transmitted and displayed. Therefore, a font can be transmitted and displayed using minimal data without sacrificing quality. On the other hand, in case of the environment, all the data can be transmitted and displayed so that the quality of the font can be fully realized.

Abstract: The present invention relates to an outline font. The purpose lies in supplying a transforming and rendering method in the shape where the important form of the shape, such as the thickness of the stroke, will be maintained from the basic shape, and at the same time the whole size of the shape can be fitted into a given bounding box. The present invention supplies the transformation method of a handwriting font including searching for the medial axis of a given element, obtaining contact points by using maximal inscribed circles with the medial axis and points of the medial axis as a center, and applying the information about the medial axis points and the contact points in case of a transformation of the element in the transformation method of handwriting where a given element can be optionally transformed in sizes in order to achieve the purpose. The present invention enables the transformation of the shape.

Abstract: Provided with a method of fabricating a 200-250 nm short-wavelength optoelectronic device, which has a combination of an optical device with a plurality of acceleration electrodes and a field emission device with a plurality of acceleration electrodes, from a semiconductor having a 5-6 eV energe band gap, based on a principle that an electron-hole pair is produced using a highly energetic electron which is injected from a field emission device, and short-wavelength photons are emitted when the electron recombines with the hole and confined in a quantum well to emit a light corresponding to the energy level of the quantum well, thereby eliminating the need of using dopants for forming n-p junctions in the semiconductor and achieving high efficiency in terms of energy because highly energetic electrons result in one or more electron-hole pairs.

Abstract: An effusion cell assembly for epitaxial apparatus is disclosed. The assembly includes an effusion cell incluing a growing material, a heater for supplying heats with the effusion cell to effuse the growing material, a supporting plate for supporting the heater, a bolt having one end connected to the supporting plate, a cell flange coupled to a lower flange of an adaptor for supporting the cell assembly, bellows fixed between the supporting plate and the cell flange including the bolt, and a control nut for expanding and contracting the bellows so as to separate only the cell assembly from a vacuum chamber with entire vacuum maintained in the vacuum chamber and local vacuum released in the cell assembly. The epitaxial apparatus further includes a control valve located between an entrance flange of the vacuum chamber and an upper adaptor flange of the adaptor for introducing and maintaining vacuum in the vacuum chamber.

Abstract: This invention discloses a method of manufacturing a diamond vacuum device, and more particularly a method of manufacturing a diamond vacuum device which uses a diamond thin film as an electron emitter by electric field. The present invention presents a method of manufacturing a vacuum device for use in high speed, high voltage, using diamond having a negative electron affinity, which can emit electrons even at a low voltage and is also resistant to chemical variations.

Abstract: The present invention relates to a method for growing new binary, ternary and quaternary epitaxial layers of III-V compound semiconductors which have the characteristics of low temperature growth, good stability and high-purity, using remote plasma, comprising the steps of converting H.sub.2 and He mixed gas into a plasma state; heating a high-purity of solid source to generate a vaporized source; reacting the vaporized source with H.sub.2 under the H.sub.2 and He plasma environment to produce V-hydrides in situ; introducing the V-hydrides directly into group III source without passing through the plasma; and reacting V-hydrides with group III source on a substrate to form an epitaxial thin layer of III-V compound semiconductors.

Abstract: An improved surface-emitting laser device by which the light emitting wave length can be easily varied since the electric potential grown using the thin film material having a desired lattice rate uses a very small portion of activation layers, and by which the continuous oscillation is made at room temperature by using the reflector having high reflective index. Thus, optical characteristics are increased, which includes a GaAs substrate; a lower reflector is formed of multiple layers of AlAs/GaAs heterogenous thin films having a reflective index of 1 on the GaAs substrate; a tooth-shaped grading layer is formed of a lower reflector on the lower reflector and an In.sub.x Ga.sub.1-x As thin film having a large lattice rate in a compositional grading method; a tooth-shaped InGaAs grading well is formed on the In.sub.x Ga.sub.1-x As grading layer as an In composition of which reduced rather than the grading layer; a buffer layer is formed on the In.sub.x Ga.sub.

Abstract: A method for sensing the completion of removal of an oxide layer from a semiconductor substrate or a super conductor by a thermal etching in real time. In the method, the time of removal of the oxide layer on the semiconductor substrate or the super conductor can ben accurately sensed. According to the method, when an oxide layer which is different from the semiconductor substrate in the refractive index is being thermally etched at a high temperature, the reflected signals of the laser beams forms a periodicity, and this periodicity is utilized so as to determine the etching rate and the time of the completion of the etching.

Abstract: A method of sensing the concentration of a doped impurity on a semiconductor in real time and a method of sensing the change of its growth rate dependent on time among the changes of the growing conditions due to doping by using a real time analysis apparatus in growing a heterostructured semiconductor by a MOCVD method. A reflecting signal during the growth by means of a real time analysis apparatus has a periodic property, an amplitude change of a reflecting signal is dependent on an absorption coefficient when an absorption exists on an epitaxial layer, an impurity concentration can be obtained by using the relation of an absorption coefficient and an impurity concentration. In addition, if each peak is independently analyzed, the respective growth rate dependent on time are measured individually, so that the reduced growth rate dependent on time of the growth rate is sensed in a carbon doped AlAs layer.