Abstract: A superconducting magnesium diboride (MgB2) thin film having c-axial orientation and a method and apparatus for fabricating the same are provided. The fabrication method includes forming a boron thin film on a substrate and thermally processing the substrate on which the boron thin film is formed along with a magnesium source and cooling the resulting structure. The superconducting magnesium diboride thin film can be used in a variety of electronic devices employing superconducting thin films, such as precision medical diagnosis equipment using superconducting quantum interface devices (SQUIDs) capable of sensing weak magnetic fields, microwave communications equipment used for satellite communications, and Josephson devices. Computer systems with 100 times greater computing speed can be implemented with the superconducting magnesium diboride thin film.

Abstract: Provided are cucurbituril derivatives having the formula (1), their preparation methods and uses: where X is O, S or NH; R1 and R2 are each independently selected from the group consisting of hydrogen, alkyl groups of 1 to 30 carbon atoms, alkenyl groups of 1 to 30 carbon atoms, alkynyl groups of 1 to 30 carbon atoms, alkylthio groups of 1 to 30 carbon atoms, alkylcarboxyl groups of 1 to 30 carbon atoms, hydroxyalkyl groups of 1 to 30 carbon atoms, alkylsilyl groups of 1 to 30 carbon atoms, alkoxy groups of 1 to 30 carbon atoms, haloalkyl groups of 1 to 30 carbon atoms, nitro group, alkylamine groups of 1 to 30 carbon atoms, amine group, aminoalkyl groups of 1 to 30 carbon atoms, unsubstituted cycloalkyl groups of 5 to 30 carbon atoms, cycloalkyl groups of 4 to 30 carbon atoms with hetero atoms, unsubstituted aryl groups of 6 to 30 carbon atoms, and aryl groups of 6 to 30 carbon atoms with hetero atoms; and n and m are independently integers from 4 to 20 and from 1 to 7, respectively.

Abstract: Uses of cucurbituril derivatives are disclosed.

Abstract: A high-efficiency, high-sensitivity absorbance detection system in a lab-on-a-chip is provided. The absorbance detection system includes detection cells having an optical pathlength ten times and/or much longer than the width of a separation channel to improve detection sensitivity, lens structures for collimating light in the detection cells, and slit structures for preventing scattered light from entering detectors. The detection cells, the lens structures, and the slit structures of the absorbance detection system are fabricated and integrated in a lab-on-a-chip. The absorbance detection system exhibits excellent absorption efficiency, detection limit, and linearity, compared to existing absorbance detection systems, and can be applied for the detection of a variety of samples. The absorbance detection system does not need labeling of the samples which saves time and costs. The absorbance detection system can be used effectively in detecting trace compounds with a high sensitivity.

Abstract: A p-type ohmic electrode in a gallium nitride based(GaN based) optical device and a fabrication method thereof. The p-type ohmic electrode in a GaN based optical device is fabricated using a rutile structure transition metal layer, such as an Ru, Ir or Os layer, or an oxide layer thereof, or using a double layer comprised of an Ru layer as a base layer and an Ni layer, an ITO layer or an AuO layer on the Ru layer. Thus, the p-type ohmic electrode is good in light transmittance and is thermally stable while having low contact resistance with the p-GaN layer.

Abstract: A multiview image synthesizing apparatus using a depth map of a stereo camera includes a multiview image synthesizing unit for converting an image signal input from first and second cameras to a digital signal and outputting a value of a depth map at a position of a virtual camera located at an arbitrary position between the first and second cameras, a multiview image re-projection unit for calculating a mapping pixel index of a multiview re-projection image for the virtual camera set by a user, by receiving the digital signal transmitted from the multiview image synthesizing unit, and outputting the calculated mapping pixel index, and a pixel selection unit for selecting a predetermined pixel to display an overlapping pixel of the digital signal input through the multiview image synthesizing unit, by using an output signal output from the multiview image re-projection unit.

Abstract: A novel multi-mode vibration damper is invented by using a pair of piezoelectric patches connected with negative capacitance shunt circuit units. A piezoelectric material connected with a series resistor-negative capacitor branch circuit is capable of suppressing the vibration and/or noise amplitudes in the low frequency range. The other piezoelectric material connected with a parallel resistor-negative capacitor circuit is for suppressing the vibration and/or noise amplitudes in the high frequency range. By combining two negative capacitance shunt circuit units, a multi-mode vibration damper is capable of suppressing the whole structure modes simultaneously. In order to describe the characteristic behaviors of a multi-mode vibration damper, the stiffness ratio and loss factor with respect to the non-dimensional frequency are considered. The mechanism of a shunt damper is also described as considering a shunt voltage generated by the shunt impedance.

Abstract: A microwave Doherty amplifier employs a way-extension in which N ways (N?2, N is a natural number) are established, and envelope tracking for high efficiency and linearity of the power amplifier of a mobile communications base station or of a handset with improved reliability. The Doherty amplifier includes N ways, where N?2 and N is a natural number; a carrier amplifier which is placed on one of the N ways; peak amplifiers which are placed on respective ways of the (N?1) ways excluding the way on which the carrier amplifier is placed; a power distribution unit which distributes power to each of the N ways; and a quarter wave impedance transformer at which the N ways meet.

Abstract: A composite containing nano magnetic particles is provided. The composite includes nano magnetic particles in a dielectric matrix. The matrix is made of an inorganic material such as silica, alumina, or hydrosilsesquioxane, or an organic material such as polyimide, polymethyl methacrylate, or methyl silsesquioxane. The nano magnetic particles consist of Fe2O3, chromium oxide, europium oxide, NiZn-ferrite, MnZn-ferrite, yttrium-iron garnet, or indium In.

Abstract: A gallium nitride (GaN) based optical device and a fabrication method thereof are provided. The GaN based optical device includes a substrate, a p-type GaN (p-GaN) layer formed on the substrate, and a p-type ohmic electrode formed on the p-GaN layer, wherein the p-type ohmic electrode is formed of a triple layer comprised of a nickel (Ni) layer, a gold (Au) layer and an indium tin oxide (ITO) layer sequentially formed. The thicknesses of the Ni layer and the Au layer forming the triple layer are smaller than the thickness of the ITO layer. When the p-type ohmic electrode in the GaN based optical device is formed of a triple layer comprised of Ni/Au/ITO, the Ni/Au layers reduce contact resistance and the ITO, which is a transparent, conductive oxide layer, increases transparency and increases luminescence efficiency.

Abstract: A liquid phase oxidation reactor is provided. The liquid phase oxidation reactor includes: a substantially cylindrical reaction vessel having an interior space of a predetermined volume; a lid combined with the reaction vessel on top of the reaction vessel; one or more stirring blades disposed within the reaction vessel and rotating by a driving source disposed on the outside of the reaction vessel; a liquid phase supplying line disposed at a sidewall of the reaction vessel for supplying a liquid phase reactant to the reaction vessel; a liquid phase discharging line disposed at a sidewall of the reaction vessel for draining a product obtained through a chemical reaction out of the reaction vessel; a gas feed nozzle formed in a bent shape for supplying an oxygen containing gas to the reaction vessel; and an angle adjusting means for supporting the gas feed nozzle so that the gas feed nozzle is turned so that the outlet thereof faces one of the stirring blades or the interior sidewall of the reaction vessel.

Abstract: A sensor prevents automobile crashes by collecting information such as a distance between automobiles, speed, and acceleration by utilizing a phenomenon that a photonic quantum ring laser emits light rays having different wavelengths associated with varying angles of the radiation from the photonic quantum ring. The sensor for preventing automobile crashes includes a photonic quantum ring laser array emitting lasing light beams having different wavelengths according to the view angle, a reflection unit for reflecting the light beams oscillated from the photonic quantum ring laser array, and a detection unit for detecting the light beams reflected by the reflection unit.

Abstract: A feedforward amplifier, and a method of improving the performance thereof, are provided. More particularly, a feedforward amplifier using imperfect cancellation of a main signal and a method of improving the performance thereof, in which, by including a predetermined amount of a main signal in an error signal that is input to an error signal cancellation loop of the feedforward amplifier, more error components of a final output signal are removed, such that the linearity and efficiency of the final output signal improve.

Abstract: Provided is a THz electromagnetic wave radiation and detection device using a high-Tc superconductor. The device includes an electromagnetic generation unit which is formed of a superconducting single crystal mesa structure where intrinsic Josephson junctions of superconducting layers and insulating layers are serially stacked and which can excite a THz electromagnetic wave; an insulating unit which contacts the electromagnetic wave generation unit and is not conductive; and an electromagnetic wave detection unit which contacts the insulating unit, is formed of the superconducting single crystal mesa structure where intrinsic Josephson junctions of the superconducting layers and the insulating layers are serially stacked and which can detect the THz electromagnetic wave. The radiation of the THz electromagnetic wave excited in the electromagnetic wave generation unit is coupled to the electromagnetic wave detection unit through the insulating unit instead of being emitted into the free space (air).

Abstract: A method for manufacturing a hetero-junction field effect transistor (HFET) device, which includes sequentially forming a non-doped GaN semiconductor layer and an AlGaN semiconductor layer on a substrate, separating devices from each other by etching the substrate, forming a photoresist layer pattern on the AlGaN semiconductor layer and forming gate electrodes by depositing a material on the substrate using the photoresist layer pattern, treating the surface of the AlGaN semiconductor layer, and forming a photoresist layer pattern on the substrate and forming ohmic electrodes by depositing a metal on the substrate using the photoresist layer pattern, is provided. Accordingly, it is possible to overcome a difficulty in aligning the gate electrode with the ohmic electrodes and prevent a substrate from having a step difference introduced by the ohmic electrodes because the gate electrode is formed before the ohmic electrodes are formed.

Abstract: A method of synthesizing carbon nanotubes and a carbon nanotube synthesizing apparatus used for the same are provided. A catalyst is introduced into the reactor, and the catalyst in the reactor is selectively and locally heated by a heating method such as microwave irradiation, electromagnetic inductive heating, radio frequency heating or laser heating. Here, carbon source gas, carbon source gas and hydrogen sulfide gas, or carbon source gas and hydrogen gas or inert gas is supplied into the reactor, thereby growing carbon nanotubes from the locally heated catalyst.

Abstract: A thermal conduction vacuum gauge using a Peltier tip is provided. The vacuum gauge for measuring the pressure in a vacuum chamber includes: a signal generator that drives an electric current; an ammeter connected to the signal generator for measuring the current; a bridge circuit consisting of junctions of thermocouple wires, which is connected to the ammeter, wherein one junction of the dissimilar metallic wires is made in the form of a Peltier tip inserted into the vacuum chamber; and a lock-in amplifier connected to the two symmetrical points of the bridge circuit for detecting a voltage signal due to the temperature oscillation at the Peltier tip and thus measuring the pressure in the vacuum chamber.

Abstract: A so-called microwave Doherty amplifier is provided. The microwave Doherty amplifier employs a way-extension method by which N ways (N≧2 N is a natural number) are established, and an envelope tracking method so that high efficiency and linearity of the power amplifier of a mobile communications base station or a handset can be achieved and price competitiveness and reliability of an apparatus employing the Doherty amplifier can be improved. The Doherty amplifier comprises N ways, where N≧2 and N is a natural number; a carrier amplifier which is placed on one of the N ways; peak amplifiers which are placed on respective ways of the (N−1 ways excluding the way on which the carrier amplifier is placed; a power distribution unit which distributes power to each of the N ways; and a quarter wave impedance transformer at which the N ways meet.

Abstract: A single-stage converter improving power factor. The single-stage converter includes a power factor improving unit, a bridge diode unit, a voltage smoothing condenser, a transformer circuit unit, and a main switch. The power factor improving unit is connected to a input power source, the bridge diode unit is located next to the power factor improving unit and provides a current path, the voltage smoothing condenser stores electrical energy provided through the bridge diode unit, the transformer circuit unit is located between the bridge diode unit and the voltage smoothing condenser, and the main switch is connected to each of the bridge diode unit, the voltage smoothing condenser, and the transformer circuit unit and controls provision of voltage to the transformer circuit unit. Thus, the single-stage converter can improve the power factor of the input terminal.

Abstract: A novel multi-mode vibration damper is invented by using a pair of piezoelectric patches connected with negative capacitance shunt circuit units. A piezoelectric material connected with a series resistor-negative capacitor branch circuit is capable of suppressing the vibration and/or noise amplitudes in the low frequency range. The other piezoelectric material connected with a parallel resistor-negative capacitor circuit is for suppressing the vibration and/or noise amplitudes in the high frequency range. By combining two negative capacitance shunt circuit units, a multi-mode vibration damper is capable of suppressing the whole structure modes simultaneously. In order to describe the characteristic behaviors of a multi-mode vibration damper, the stiffness ratio and loss factor with respect to the non-dimensional frequency are considered. The mechanism of a shunt damper is also described as considering a shunt voltage generated by the shunt impedance.