摘要:
A ventilator for a casting mold is mounted on an exhaust pipe (11) of a mold (10) to emit gas generated when melt is injected into a molding space (12). The ventilator for a casting mold has exhaust holes which are improved in arrangement structure and are shorter than a cylindrical body part so as to enhance gas emission efficiency and prevent transformation of the exhaust holes, and has a buffering space part formed inside a cylindrical body part to spread and accept melt coming through the exhaust holes so as to effectively prevent a damage of a mold caused by external leakage of the melt. The ventilator for the casting mold includes a cylindrical body part (100) and a fixed type exhaust block (20).
摘要:
Provided are an apparatus and method for transmitting multi-carriers to provide a high-quality service to multicast-based service subscriber terminals. The method includes: mapping first data for providing the multicast service, and second data different from the first data, to different antennas; converting the first mapped data into a first Intermediate Frequency (IF) signal and the second mapped data into a second IF signal; converting the first IF signal into a first RF signal having a carrier frequency, and deciding a power intensity of the first RF signal so that the first RF signal is transmitted over the entire coverage region of the base station; and converting the second IF signal into a second RF signal having the other carrier frequency, and deciding a power intensity of the second RF signal so that the second RF signal is transmitted over a predetermined region around the base station.
摘要:
The present invention relates to a system and a method for a mobile broadcast service, a controller, and a method for driving the controller. The system for a mobile broadcast service forms an MBS zone only with base stations having user demand for an MBS. For example, when there is a request for an MBS from a base station, if an MBS zone already exists which is providing the requested MBS, then the corresponding base station is included in the previously generated MBS zone. In contrast, if there are no more users using an MBS via a base station that is part of an MBS zone, then the base station in question is excluded from the MBS zone. Thus, an MBS zone can be dynamically formed by including or excluding a base station, forming an MBS zone, on the basis of an existence of an MBS user.
摘要:
The present invention relates to an IPTV service device and method for providing continuous service. The method according to one embodiment of the present invention comprises: a service-request receiving step of receiving an IPTV service request from a user of an IPTV terminal; a service-confirming step of confirming whether or not the IPTV service has previously been stopped in response to the IPTV service request; and an IPTV-service providing step of providing the IPTV service to the IPTV terminal from the point at which service was stopped if the IPTV service has previously been stopped.
摘要:
A timestamping apparatus for network synchronization includes a recovery unit and a timestamping unit. The recovery unit extracts a recovery clock operating at an operation frequency of a transmission terminal from a sync signal received from the transmission terminal. The timestamping unit measures a timestamp value of an arrival time of the sync signal by measuring a phase difference between the recovery clock and a local clock of a receiving terminal.
摘要:
A technology is provided capable of improving the efficiency of an OFDM system by obtaining the performance in Bit Error Rate (BER) in a wireless communication using OFDM and determining the minimum FFT input bit that produces a SNR difference of 0.1 dB or below with respect to a theoretical BER graph at a desired performance.
摘要:
An efficient switching device and a method for fabricating the same using multiple shared memories are provided. The switching device includes: an output time determination unit to determine an output time to an output port; an output time administration unit to administer a possible data output time for each output port; a memory bank selection unit to select a memory bank with an empty data output time position; a memory bank utilization information administration unit to administer utilization information per output time; a connection unit to deliver transmission data to an output time position; a shared memory unit to store the data in the output time position, to administer dispersed shared memory banks according to an output time, and to read and output transmission data; and an output port connection unit receiving output data to read and transmit output port information of the data to a corresponding output port.
摘要:
Provided is a dynamic rate-limiting method and apparatus used in a switch for switching packets from input ports to output ports, the method including: (a) adding traffic bandwidth values set in advance in active subscribers that are using the switch from among subscribers connected to the switch; (b) comparing the added value with a range between a maximum bandwidth and a minimum bandwidth that are set in the switch; and (c) according to a result of comparing, when the added values is smaller than the minimum bandwidth or larger than the maximum bandwidth set in the switch, increasing or decreasing the traffic bandwidths of the active subscribers set in advance so that the added value is within the range between the maximum bandwidth and minimum bandwidth. Accordingly, it is possible to automatically control the traffic bandwidths of subscribers that are currently using the switch.
摘要:
Provided are a method and apparatus for configuring a Multicast and Broadcast Service (MBS) zone dynamically in a mobile communication environment. According to an example, there is provided a method of seamlessly changing base stations configuring a MBS zone whenever one or more mobile terminals configuring the MBS zone move or whenever a predetermined time period has elapsed to thereby provide a MBS with excellent quality while saving radio resources.
摘要:
A method and an apparatus for acquiring initial synchronization in a wireless communication system are provided. A relay station determines whether or not the initial synchronization is acquired, determines a start position of a frame using a peak of an autocorrelation signal detected based on a preamble and a relay-amble (R-amble) received from a base station in the case in which the initial synchronization is not acquired, and determines the start position of the frame using a peak of an autocorrelation signal detected based on the relay-amble received from the base station in the case in which the initial synchronization is acquired.