Abstract: A buck-boost converter includes a first switch connected between an input terminal that receives an input voltage and a first terminal of an inductor, a second switch connected between the first terminal of the inductor and an output terminal that outputs an output voltage, a third switch connected between a second terminal of the inductor and a ground terminal, and a fourth switch connected between the second terminal of the inductor and an inverting input terminal that receives an inverted input voltage obtained by inverting the input voltage.

Abstract: A memory controller includes a clock scaler, a bus component and a level monitor. The clock scaler is configured to receive a first clock signal and configured to generate a second clock signal based on the first clock signal, first and second frequency control signals. A frequency of the second clock signal may increase based on the first frequency control signal and decrease based on the second frequency control signal. The bus component may operate based on the second clock signal and generate a level signal corresponding to a current operating state of the bus component. The level monitor may generate the first and second frequency control signals based on the level signal, a first threshold value, a second threshold value, a first reference time, and a second reference time.

Abstract: A method and an apparatus of providing education contents are provided. The method includes transmitting education contents to a display device in response to an education contents request received from the display device, receiving, from a personal device, a personal request that is associated with the education contents and comprises an education contents identifier of the education contents, generating a personal response to the personal request received from the personal device and transmitting the generated personal response to the personal device.

Abstract: A memory controller includes a clock scaler, a bus component and a level monitor. The clock scaler is configured to receive a first clock signal and configured to generate a second clock signal based on the first clock signal, first and second frequency control signals. A frequency of the second clock signal may increase based on the first frequency control signal and decrease based on the second frequency control signal. The bus component may operate based on the second clock signal and generate a level signal corresponding to a current operating state of the bus component. The level monitor may generate the first and second frequency control signals based on the level signal, a first threshold value, a second threshold value, a first reference time, and a second reference time.

Abstract: There is provided a method and a system of providing a seamless service. The method includes receiving seamless service application information from a first device; receiving, from a second device, history information of at least one application executed by the second device; receiving a seamless service request from the first device; generating seamless service data for the first device, in response to the request, based on the received seamless service application information and the received history information; and transmitting the generated seamless service data to the first device, wherein the first device executes at least one seamless service application based on the transmitted seamless service data.

Abstract: A method and system for efficiently transmitting data, to which scalable image coding has been applied over a single frequency network is provided. The system includes a control server which re-packetizes data packets, received from a multimedia server, into a scalable bit stream by separately encoding the data packets into a base layer and one or more enhancement layers, and at least one base station which adaptively multicasts and broadcasts the scalable bit stream, received from the control server, to a plurality of terminals located in the area of a cell. The at least one base station multicasts and broadcasts the base layer across the area of the cell, and adaptively transmits the one or more enhancement layers depending on channel status or terminal performance of the plurality of terminals.

Abstract: There is provided a method and a system of providing a seamless service. The method includes receiving seamless service application information from a first device; receiving, from a second device, history information of at least one application executed by the second device; receiving a seamless service request from the first device; generating seamless service data for the first device, in response to the request, based on the received seamless service application information and the received history information; and transmitting the generated seamless service data to the first device, wherein the first device executes at least one seamless service application based on the transmitted seamless service data.

Abstract: A method and system for efficiently transmitting data, to which scalable image coding has been applied over a single frequency network is provided. The system includes a control server which re-packetizes data packets, received from a multimedia server, into a scalable bit stream by separately encoding the data packets into a base layer and one or more enhancement layers, and at least one base station which adaptively multicasts and broadcasts the scalable bit stream, received from the control server, to a plurality of terminals located in the area of a cell. The at least one base station multicasts and broadcasts the base layer across the area of the cell, and adaptively transmits the one or more enhancement layers depending on channel status or terminal performance of the plurality of terminals.

Abstract: The present invention provides a semiconductor manufacturing apparatus having a slit valve control system including first and second process chambers disposed adjacent to each other, a slit aperture disposed between the first and second chambers, a slit valve to open and close the slit aperture between first and second chambers, an air source to operate the slit valve, a pressure supply flow path connecting the slit valve with the air source, and a pressure regulator installed on the supply flow path to regulate pressure supplied from the air source to the slit valve.

Abstract: The present invention provides a semiconductor manufacturing apparatus having a slit valve control system including first and second process chambers disposed adjacent to each other, a slit aperture disposed between the first and second chambers, a slit valve to open and close the slit aperture between first and second chambers, an air source to operate the slit valve, a pressure supply flow path connecting the slit valve with the air source, and a pressure regulator installed on the supply flow path to regulate pressure supplied from the air source to the slit valve.

Abstract: An induction magnet for use in semiconductor device manufacturing equipment is formed of an insulating magnetic material. The semiconductor device manufacturing equipment may include a reaction chamber having a plasma region in which plasma is produced, a substrate support disposed in the reaction chamber, a gas supplier that sprays reaction gas uniformly towards the substrate support, and a power supply for supplying a high frequency that excites the reaction gas to produce plasma in the plasma region. The induction magnet is disposed around the plasma region at the outside of the reaction chamber. Because of the composition of the induction magnet, the semiconductor manufacturing equipment does not overheat even though power having a high frequency is applied to the induction magnet. As a result, the semiconductor device manufacturing equipment can perform a manufacturing process with a high degree of productivity.

Abstract: A method of performing a continuity check on a speech channel in an electronic exchange system includes indicating and transmitting a continuity check request on a continuity check indicator located in a head address message if characteristics of a trunk module turn out the continuity check request while handling an outgoing call to a counterpart, and connecting a speech channel with a continuity check tone transceiver to transmit therethrough a continuity check tone; monitoring whether the continuing check tone that was transmitted through a forward channel is received back through a backward channel within a predetermined time; and if said continuity check tone is received back, terminating transmission of the speech channel from the continuity check tone, causing a timer to stop counting, and disconnecting said continuity check tone transceiver.