Abstract: Disclosed herein is a process for the preparation of dimethylether from hydrocarbons, including tri-reforming a feedstock mixture comprised of hydrocarbons, carbon dioxide and water vapor in the presence of a tri-reforming catalyst, to prepare a syngas, which then undergoes gas-phase direct synthesis into dimethylether in one step in the presence of a hybrid catalyst. According to the process of this invention, three main processes among typical syngas preparation processes are simultaneously performed, and then, the syngas thus obtained is prepared into dimethylether through a direct reaction in one step, thereby decreasing the apparatus cost and operation cost. In addition, all of the carbon dioxide separated and recovered from the unreacted material and by-products may be reused as reaction material, thus decreasing the generation of carbon dioxide and reducing the material cost.

Abstract: An optical pickup actuator for use with a recording medium includes a swing arm pivoting in a tracking direction with respect to the recording medium, a first driving unit pivoting the swing arm, an optical pickup facing the recording medium, an elastic member having one end fixed to the swing arm and a free end portion elastically deformable in a focus direction with respect to the recording medium, wherein the optical pickup is coupled to the free end portion of the elastic member, and a second driving unit deforming and driving the elastic member.

Abstract: An optical pickup capable of effectively reducing chromatic aberration that includes a collimating lens, which includes a diverging lens with diverging power and a focusing lens with focusing power, arranged on the optical path between a light source and an objective lens, wherein assuming that the total focal length of the collimating lens is f and the focal length of the diverging lens is fn, the collimating lens satisfies the relationship ?1.5>f/fn. The optical pickup is compatible with both existing digital versatile disks (DVDs), and high-definition (HD)-DVDs, which will not yet standardized, need a blue light source near 405 nm and an objective lens having an numerical aperture of 0.6 or more.

Abstract: An optical pickup apparatus for compensating for the deviation in the thickness of the optical disk and method therefor.

Abstract: An optical pickup for a recording medium includes a light beam division and detection unit including receiving portions dividing an incident light beam reflected on the recording medium into a first light beam portion and a second light beam portion around the first light beam portion and converting the first and second light beam portions into first and second detection signals, respectively. A thickness variation detection circuit detects a variation in thickness of the recording medium according to the first and second detection signals and outputs a thickness variation signal indicative thereof.

Abstract: An optical pickup is provided for a recording medium, including: a light source generating and emitting a light beam; a light beam division and detection unit dividing a particular light beam portion of the light beam after being reflected/diffracted from the recording medium into sub-divided light beams portions, and detecting the sub-divided light beam portions; and a spherical aberration detection circuit processing the sub-divided light beam portions to detect spherical aberration caused by thickness variation of the recording medium.

Abstract: A method and circuit for providing a playback signal which is compensated for time delay. The circuit includes a time delay compensator for detecting a time difference between outputs of a photodetector and temporally matching part of the outputs of the photodetector and another part of the outputs of the photodetector, between which the time difference occurs, to compensate for time delay between different outputs of the photodetector, and an operational unit for summing the part of the outputs of the photodetector, which is compensated for the time delay, and the other part of the outputs of the photodetector to provide a playback signal. Accordingly, the circuit compensates for the time delay between the outputs of the photodetector, thereby increasing the degree of modulation of the data playback signal.

Abstract: An optical pickup device includes a light source to emit light, an objective lens to focus the light on a recording medium to form a light spot, an optical path changer on an optical path between the light source and the objective lens to change the path of incident light, a chromatic aberration correction lens disposed on an optical path between the light source and the objective lens, and a photodetector to receive light which is reflected from the recording medium and is then incident thereon through the optical path changer. The chromatic aberration correction lens corrects a chromatic aberration occurring due to a change in the wavelength and/or due to an increase in a wavelength bandwidth of the light. The chromatic aberration correction lens includes at least two lenses such that a lens having a positive power and a lens having a negative power are adjacent to each other.

Abstract: Provided is a method of purifying a vancomycin from a fermentation broth of a microorganism containing vancomycin, including passing the fermentation broth of a microorganism containing vancomycin through a strong acid cation exchange resin, a weak base anion exchange resin, alumina and a hydrophobic absorbent resin sequentially.

Abstract: An optical pickup for a recording medium includes a light beam division and detection unit including receiving portions dividing an incident light beam reflected on the recording medium into a first light beam portion and a second light beam portion around the first light beam portion and converting the first and second light beam portions into first and second detection signals, respectively. A thickness variation detection circuit detects a variation in thickness of the recording medium according to the first and second detection signals and outputs a thickness variation signal indicative thereof.

Abstract: In a multi-carrier communication system where a base station performs resource allocating power allocation and adaptive modulation processes for a mobile station by using CSI (Channel State Information) received from the mobile station, a CSI feedback method in accordance with the present invention determines a CSI transmission mode according to an amount of data traffic on a reverse link, encodes CSI for subcarriers into one CSI codeword according to the determined CSI transmission mode, and transmits the CSI codeword to the base station. Since the CSI is adaptively transmitted according to the amount of the data traffic of the reverse link, it can effectively use resources of the reverse link.

Abstract: The present invention is directed to a packaging system and apparatus for transporting digital media, such as DVDs or compact discs. In accordance with a preferred embodiment of the present invention, the packaging system includes an inner pocket made of high-density polyethylene fiber material for retaining digital media such as DVDs or compact discs, a protective jacket made of reinforced material such as cardboard into which the inner pocket may be inserted, a light-weight envelope with an opening into which the protective jacket and the inner pocket containing the digital media may be inserted, where the envelope has a detachable lid for sealing the envelope.

Abstract: An optical pickup device includes a light source to emit light, an objective lens to focus the light on a recording medium to form a light spot, an optical path changer on an optical path between the light source and the objective lens to change the path of incident light, a chromatic aberration correction lens disposed on an optical path between the light source and the objective lens, and a photodetector to receive light which is reflected from the recording medium and is then incident thereon through the optical path changer. The chromatic aberration correction lens corrects a chromatic aberration occurring due to a change in the wavelength and/or due to an increase in a wavelength bandwidth of the light. The chromatic aberration correction lens includes at least two lenses such that a lens having a positive power and a lens having a negative power are adjacent to each other.

Abstract: A robot arm has an impact absorption structure for absorbing impact energy caused by a collision to protect a person from injury and the robot arm from being damaged. The robot arm includes a plurality of rigid beams provided at both end portions thereof to define a frame of the robot arm, and side members made of an elastic material and provided between the plurality of rigid beams to define an appearance of the robot arm and absorb the impact energy. Each side member includes a sheet made of a plastic material, a foam or honeycomb structure, and a fiber reinforced composite material attached to the sheet.

Abstract: The present invention is directed to a packaging system and apparatus for transporting digital media, such as DVDs or compact discs. In accordance with a preferred embodiment of the present invention, the packaging system includes an inner pocket made of high-density polyethylene fiber material for retaining digital media such as DVDs or compact discs, a protective jacket made of reinforced material such as cardboard into which the inner pocket may be inserted, a light-weight envelope with an opening into which the protective jacket and the inner pocket containing the digital media may be inserted, where the envelope has a detachable lid for sealing the envelope.

Abstract: An optical pickup includes an aberration correction element to correct chromatic aberration caused by variation of power from a light source when changing between operating modes in a recording medium. The aberration correction includes a first retardation member, which includes a stepped convex pattern with a plurality of steps at one side, and a second retardation member combined with the first retardation member. The second retardation member includes a stepped concave pattern with a plurality of steps at one side facing the first retardation member, the stepped concave pattern corresponding to the stepped convex pattern. The first and the second retardation members include different refractive indices for a light beam, which allows the first and the second retardation members to selectively create a phase difference of an incident light beam according to a polarization of the incident light beam.

Abstract: An optical pickup apparatus for compensating for the deviation in the thickness of the optical disk and method therefor.

Abstract: A method of and a circuit for providing a playback signal, which is compensated for time delay, from a photodetector having a plurality of outputs. A time difference between a first signal corresponding to a part of the outputs of the photodetector and a second signal corresponding to another part of the outputs of the photodetector is detected and one of the first and second signals is temporally shifted to compensate for a time delay between different outputs of the photodetector. The temporally shifted signal is summed with the other signal to provide a playback signal. Accordingly, the time delay between the outputs of the photodetector is compensated, thereby increasing the degree of modulation of the data playback signal. In addition, distortion or degradation of the signal is suppressed and occurrence of errors in the playback signal is minimized, thereby improving the reliability of the playback signal.

Abstract: An optical pickup apparatus for compensating for the deviation in the thickness of the optical disk and method therefor.

Abstract: An optical pickup apparatus including a swing arm pivotably installed in a tracking direction with respect to a disc, and an optical pickup unit supported by the swing arm and driven in a focusing direction, wherein the optical pickup unit includes a laser diode, an objective lens to focus light emitted from the laser diode on a recording surface of the disc, and a heat sink plate to dissipate heat generated from the laser diode, wherein the heat sink plate is provided close to the disc so as to be directly exposed to wind generated during rotation of the disc.