Abstract: A wireless communication system for geographically controlling a communication area includes an access point for communicating with a terminal in a first area, and a jammer for generating noise for intercepting communication between the access point and a terminal in a second area. A jamming boundary for dividing an area in which the terminal can communicate with the access point and an area in which the terminal cannot communicate with the access point in an area in which the first area and the second area are overlapped is formed, and the jamming boundary is formed by a ratio between power of a signal transmitted to the terminal by the access point and power of a signal of the noise.

Abstract: There is provided a nitride semiconductor light emitting device including: a light emitting structure including n-type and p-type nitride semiconductor layers and an active layer disposed therebetween; n- and p-electrodes electrically connected to the n-type and p-type nitride semiconductor layers, respectively; and an n-type ohmic contact layer disposed between the n-type nitride semiconductor layer and the n-electrode and including a first layer and a second layer, the first layer formed of an In-containing material, and the second layer disposed on the first layer and formed of a transparent conductive oxide. The nitride semiconductor light emitting device including the n-electrode exhibits high light transmittance and superior electrical characteristics. Further, the nitride semiconductor light emitting device can be manufactured by an optimal method to ensure superb optical and electrical characteristics.

Abstract: Solid anion exchange polymer electrolytes and compositions comprising chemical compounds comprising a polymeric core, a spacer A, and a guanidine base, wherein said chemical compound is uniformly dispersed in a suitable solvent and has the structure: wherein: i) A is a spacer having the structure O, S, SO2, —NH—, —N(CH2)n, wherein n=1-10, —(CH2)n—CH3—, wherein n=1-10, SO2-Ph, CO-Ph, wherein R5, R6, R7 and R8 each are independently —H, —NH2, F, Cl, Br, CN, or a C1-C6 alkyl group, or any combination of thereof; ii) R9, R10, R11, R12, or R13 each independently are —H, —CH3, —NH2, —NO, —CHnCH3 where n=1-6, HC?O—, NH2C?O—, —CHnCOOH where n=1-6, —(CH2)n—C(NH2)—COOH where n=1-6, —CH—(COOH)—CH2—COOH, —CH2—CH(O—CH2CH3)2, —(C?S)—NH2, —(C?NH)—N—(CH2)nCH3, where n=0-6, —NH—(C?S)—SH, —CH2—(C?O)—O—C(CH3)3, —O—(CH2)n—CH—(NH2)—COOH, where n=1-6, —(CH2)n—CH?CH wherein n=1-6, —(CH2)n—CH—CN wherein n=1-6, an aromatic group such as a phenyl, benzyl, phenoxy, methylbenzyl, nitrogen-substituted benzyl or phenyl g

Abstract: Compositions, and methods of making thereof, comprising from about 1% to about 5% of a perfluorinated sulfonic acid ionomer or a hydrocarbon-based ionomer; and from about 95% to about 99% of a solvent, said solvent consisting essentially of a polyol; wherein said composition is substantially free of water and wherein said ionomer is uniformly dispersed in said solvent.

Abstract: There is provided a method of forming a pattern on a group III nitride semiconductor substrate. A method of forming a pattern on a group III nitride semiconductor substrate according to an aspect of the invention may include: irradiating a laser beam onto at least one first region for preventing etching in a group III nitride semiconductor substrate; and etching at least one second region exclusive of the first region using the first region irradiated with the laser beam as a mask.

Abstract: There is provided a method of forming a pattern on a group III nitride semiconductor substrate. A method of forming a pattern on a group III nitride semiconductor substrate according to an aspect of the invention may include: irradiating a laser beam onto at least one first region for preventing etching in a group III nitride semiconductor substrate; and etching at least one second region exclusive of the first region using the first region irradiated with the laser beam as a mask.

Abstract: Compositions, and methods of making thereof, comprising from about 1% to about 5% of a perfluorinated sulfonic acid ionomer or a hydrocarbon-based ionomer; and from about 95% to about 99% of a solvent, said solvent consisting essentially of a polyol; wherein said composition is substantially free of water and wherein said ionomer is uniformly dispersed in said solvent.

Abstract: Sulfonated polymers are made by the direct polymerization of a sulfonated monomer to form the sulfonated polymers. The types of sulfonated polymers may include polysulfones or polyimides. The sulfonated polymers can be formed into membranes that may be used in proton exchange membrane fuel cells or as ion exchange membranes. The membranes formed from the sulfonated polymers exhibit improved properties over that of Nafion®. A heteropoly acid may be added to the sulfonated polymer to form a nanocomposite membrane in which the heteropoly acid is highly dispersed. The addition of a heteropoly acid to the sulfonated polymer increases the thermal stability of the membrane, enhances the conductivity above 100° C., and reduces the water uptake of the membrane.

Abstract: Method of making a membrane electrode assembly comprising: providing a membrane comprising a perfluorinated sulfonic acid; providing a first transfer substrate; applying to a surface of the first transfer substrate a first ink, said first ink comprising an ionomer and a catalyst; applying to the first ink a suitable non-aqueous swelling agent; forming an assembly comprising: the membrane; and the first transfer substrate, wherein the surface of the first transfer substrate comprising the first ink and the non-aqueous swelling agent is disposed upon one surface of the membrane; and heating the assembly at a temperature of 150° C. or less and at a pressure of from about 250 kPa to about 3000 kPa or less for a time suitable to allow substantially complete transfer of the first ink and the second ink to the membrane; and cooling the assembly to room temperature and removing the first transfer substrate and the second transfer substrate.

Abstract: A wavelength conversion laser device and a nonlinear optical crystal used in the same. The wavelength conversion laser device includes a laser light source for emitting a predetermined wavelength beam, and a laser medium for exciting the predetermined wavelength beam from the laser light source into a fundamental beam. The wavelength conversion laser device further includes a nonlinear optical crystal composed of a KTiOPO4 (KTP) crystal having b-c crystal plane as an incident surface of the fundamental beam to provide type II phase matching conditions. The KTP crystal converts the fundamental wavelength beam into a second harmonic generation beam.

Abstract: There is provided a method of forming a pattern on a group III nitride semiconductor substrate. A method of forming a pattern on a group III nitride semiconductor substrate according to an aspect of the invention may include: irradiating a laser beam onto at least one first region for preventing etching in a group III nitride semiconductor substrate; and etching at least one second region exclusive of the first region using the first region irradiated with the laser beam as a mask.

Abstract: The present invention provides a semiconductor light emitting device including a conductive substrate, a first electrode layer, an insulating layer, a second electrode layer, a second semiconductor layer, an active layer, and a first semiconductor layer which are sequentially stacked, wherein an area where the first electrode layer and the first semiconductor layer are in contact with each other is 3 to 13% of an area of the semiconductor light emitting device.

Abstract: A method of removing contaminants from a fuel cell catalyst electrode. The method includes providing a getter electrode and a fuel cell catalyst electrode having at least one contaminant to a bath and applying a voltage sufficient to drive the contaminant from the fuel cell catalyst electrode to the getter electrode. Methods of removing contaminants from a membrane electrode assembly of a fuel cell and of improving performance of a fuel cell are also provided.

Abstract: There is provided a nitride semiconductor light emitting device including: a light emitting structure having n-type and p-type nitride semiconductor layers and an active layer formed therebetween; n-type and p-type electrodes electrically connected to the n-type and p-type nitride semiconductors, respectively; and an n-type ohmic contact layer formed between the n-type nitride semiconductor layer and the n-type electrode and having a first layer formed of a material containing In and a second layer formed on the first layer and formed of a material containing W. According to an aspect of the invention, there is provided a nitride semiconductor light emitting device that has an n-type electrode having thermal stability and excellent electrical characteristics without heat treatment. According to another aspect of the invention, there is provided a method of manufacturing a nitride semiconductor light emitting device optimized to obtain the excellent thermal and electrical characteristics.

Abstract: There is provided a nitride semiconductor light emitting device including: a light emitting structure including n-type and p-type nitride semiconductor layers and an active layer disposed therebetween; n- and p-electrodes electrically connected to the n-type and p-type nitride semiconductor layers, respectively; and an n-type ohmic contact layer disposed between the n-type nitride semiconductor layer and the n-electrode and including a first layer and a second layer, the first layer formed of an In-containing material, and the second layer disposed on the first layer and formed of a transparent conductive oxide. The nitride semiconductor light emitting device including the n-electrode exhibits high light transmittance and superior electrical characteristics. Further, the nitride semiconductor light emitting device can be manufactured by an optimal method to ensure superb optical and electrical characteristics.

Abstract: Disclosed are a semiconductor light emitting device, which can improve characteristics of the semiconductor light emitting device such as a forward voltage characteristic and a turn-on voltage characteristic, increase light emission efficiency by lowering an input voltage, and increase reliability of the semiconductor light emitting device by a low-voltage operation, and a method of manufacturing the same. The semiconductor light emitting device includes: an n-type GaN semiconductor layer; an active layer formed on a gallium face of the n-type GaN semiconductor layer; a p-type semiconductor layer formed on the active layer; and an n-type electrode formed on a nitrogen face of the n-type GaN semiconductor layer and including a lanthanum (La)-nickel (Ni) alloy.

Abstract: A semiconductor laser device comprises: a substrate having a top surface divided into a first region and a second region; a high-output LD including a first conductivity-type clad layer, an active layer, and a second conductivity-type clad layer including an upper portion having a first ridge structure, sequentially formed on the first region of the substrate; and a low-output LD including a first conductivity-type clad layer, an active layer, and a second conductivity-type clad layer including an upper portion having a second ridge structure, sequentially formed on the second region of the substrate, wherein the first and second ridge structures are formed in such a manner that they are extended to both ends opposed to each other, the first ridge structure is bent at two or more bending positions, and the second ridge structure is rectilinear.

Abstract: Sulfonated polymers are made by the direct polymerization of a sulfonated monomer to form the sulfonated polymers. The types of sulfonated polymers may include polysulfones or polyimides. The sulfonated polymers can be formed into membranes that may be used in proton exchange membrane fuel cells or as ion exchange membranes. The membranes formed from the sulfonated polymers exhibit improved properties over that of Nafion®. A heteropoly acid may be added to the sulfonated polymer to form a nanocomposite membrane in which the heteropoly acid is highly dispersed. The addition of a heteropoly acid to the sulfonated polymer increases the thermal stability of the membrane, enhances the conductivity above 100° C., and reduces the water uptake of the membrane.

Abstract: Sulfonated polymers are made by the direct polymerization of a sulfonated monomer to form the sulfonated polymers. The types of sulfonated polymers may include polysulfones or polyimides. The sulfonated polymers can be formed into membranes that may be used in proton exchange membrane fuel cells or as ion exchange membranes. The membranes formed from the sulfonated polymers exhibit improved properties over that of Nafion®. A heteropoly acid may be added to the sulfonated polymer to form a nanocomposite membrane in which the heteropoly acid is highly dispersed. The addition of a heteropoly acid to the sulfonated polymer increases the thermal stability of the membrane, enhances the conductivity above 100° C., and reduces the water uptake of the membrane.

Abstract: A wavelength conversion laser device and a nonlinear optical crystal used in the same. The wavelength conversion laser device includes a laser light source for emitting a predetermined wavelength beam, and a laser medium for exciting the predetermined wavelength beam from the laser light source into a fundamental beam. The wavelength conversion laser device further includes a nonlinear optical crystal composed of a KTiOPO4 (KTP) crystal having b-c crystal plane as an incident surface of the fundamental beam to provide type II phase matching conditions. The KTP crystal converts the fundamental wavelength beam into a second harmonic generation beam.