Abstract: A superlattice structure, and a semiconductor device including the same, include a plurality of pairs of layers are in a pattern repeated at least two times, in which a first layer and a second layer constitute a pair, the first layer is formed of AlxInyGa1-x-yN (where 0?x and y?1), the second layer is formed of AlaInbGa1-a-bN (where 0?a, b?1 and x?a), the first and second layers have the same thickness, and a total thickness of each of the plurality of pairs of layers is different than each other.

Abstract: A gallium nitride based semiconductor device includes a silicon-based layer doped simultaneously with boron (B) and germanium (Ge) at a relatively high concentration, a buffer layer on the silicon-based layer, and a nitride stack on the buffer layer. A doping concentration of boron (B) and germanium (Ge) may be higher than 1×1019/cm3.

Abstract: Crack formation and propagation in a silicon substrate may be reduced by forming a crack reducing portion. The silicon substrate includes a silicon main portion and a silicon edge portion formed around the silicon main portion. The crack reducing portion is formed on the silicon edge portion of the silicon substrate such that the directions of crystal faces in the crack reducing portion are randomly oriented.

Abstract: A mobile communication system selection is disclosed. A method for selecting a mobile communication system of a portable terminal includes driving a first timer; checking whether a Mobile Country Code (MCC) of a region where the portable terminal is located is obtained by searching for a network until the first timer expires; when the MCC is obtained before the first timer expires, storing the obtained MCC to a previous MCC list; performing a first checking operation for checking whether the obtained MCC belongs to a list of countries supporting only a first mobile communication system; and obtaining a service of the first mobile communication system by searching for only the first mobile communication system when the obtained MCC belongs to the list of the countries supporting only the first mobile communication system.

Abstract: A tub having a structurally strengthened rear wall and a washing machine with the same therein are disclosed. A washing machine includes a bearing housing having a flange part and a tub injection-molded with the bearing housing inserted into a wall thereof, the wall having a recessing part and a projecting part formed on an inner or an outer surface thereof along a circumferential direction, and a circumferential rib or a radial rib formed on the recessing part.

Abstract: A foam filter for an aquarium having a function for purifying water and air which is capable of facilitating a replacement and maintenance of components due to an abnormality of a filtering device and an execution of a washing operation (including water refill) of the aquarium by making it convenient to be manufactured and installed depending on a simplified construction of a product which can be selectively disassembled or assembled, and also capable of satisfying user's visual curiosity by improving an externality of the aquarium, wherein the foam filter for the aquarium having the function for purifying water and air can be achieved by being provided with an installation case provided with a pair of container installation holes which are symmetrical to each other at left and right lateral surfaces based upon a filter installation hole, and having a fluid inlet which is formed through the filter installation hole at central front portion of a bottom surface of the installation case, a multi-layer filter sli

Abstract: A mobile communication system selection is disclosed. A method for selecting a mobile communication system of a portable terminal includes driving a first timer; checking whether a Mobile Country Code (MCC) of a region where the portable terminal is located is obtained by searching for a network until the first timer expires; when the MCC is obtained before the first timer expires, storing the obtained MCC to a previous MCC list; performing a first checking operation for checking whether the obtained MCC belongs to a list of countries supporting only a first mobile communication system; and obtaining a service of the first mobile communication system by searching for only the first mobile communication system when the obtained MCC belongs to the list of the countries supporting only the first mobile communication system.

Abstract: An apparatus and a method of a portable terminal using a high speed downlink packet data service, for reselecting a cell that supports HSDPA, are provided, which include a communication unit for receiving a broadcast message, a broadcast message reading unit for determining whether there is a cell which supports the HSDPA service by reading the received broadcast message, and sending the result to the control unit, and the control unit for controlling the communication unit and the broadcast message reading unit.