Abstract: The present disclosure relates to a method of preparing a polymer, which includes: adding an alkyl-substituted aromatic vinyl-based monomer and a vinyl cyanide-based monomer to a reactor and initiating polymerization; and performing polymerization while continuously adding an alkyl-substituted aromatic vinyl-based monomer and a multifunctional initiator to the reactor, wherein the continuous addition of the alkyl-substituted aromatic vinyl-based monomer and the multifunctional initiator is initiated when a polymerization conversion rate is 10 to 30%, and the continuous addition of the alkyl-substituted aromatic vinyl-based monomer and the multifunctional initiator is terminated when a polymerization conversion rate is 70 to 80%.

Abstract: A local wireless signal receiving apparatus using digital RF processing technology including: a receiving digital RF processor receiving an RF signal and detecting an IF signal from the received RF signal; a zero-crossing signal detector detecting a zero-crossing signal from the detected IF signal, and converting the detected zero-crossing signal into a digital signal; and a receiving signal processor converting the digital signal into a local wireless signal.

Abstract: The present invention relates to a system and to a method for QoS (Quality of Service) support in a ubiquitous sensor network. The system for QoS support in a ubiquitous sensor network includes a mesh coordinator and nodes. The mesh coordinator organizes a super frame containing a dedicated QoS data transmission period, and synchronizes each of the nodes constituted into one network with the abovementioned super frame. The nodes create a beacon frame containing information on whether or not to set QoS, to broadcast the beacon frame in a dedicated beacon period of the super frame if QoS data transmission is needed, to create a QoS data frame with a set priority, and to transmit the QoS data frame to the dedicated QoS data transmission period of the super frame in the case of transmitting QoS data.

Abstract: The present invention relates to apparatus and method of providing a multimedia advertising service through a mobile communication network. In the present invention, a content server downloads ad contents to a mobile terminal along with content-displaying condition and the mobile terminal having received the ad contents displays the received ad contents according to the content-displaying condition when an event specified by the content-displaying condition occurs. Afterwards, a content-displayed history is uploaded to the content server by the mobile terminal.

Abstract: The present invention relates to a system and to a method for QoS (Quality of Service) support in a ubiquitous sensor network. The system for QoS support in a ubiquitous sensor network includes a mesh coordinator and nodes. The mesh coordinator organizes a super frame containing a dedicated QoS data transmission period, and synchronizes each of the nodes constituted into one network with the abovementioned super frame. The nodes create a beacon frame containing information on whether or not to set QoS, to broadcast the beacon frame in a dedicated beacon period of the super frame if QoS data transmission is needed, to create a QoS data frame with a set priority, and to transmit the QoS data frame to the dedicated QoS data transmission period of the super frame in the case of transmitting QoS data.

Abstract: A local wireless signal transmitting/receiving apparatus and method using digital RF processing technology. When the local wireless signal transmitting/receiving apparatus generates a local wireless signal to be transmitted, spreads the frequency of the generated local wireless signal and thereby generates a baseband signal, the local wireless signal transmitting/receiving apparatus converts the baseband signal of the local wireless signal into phase information, converts the phase information into an RF signal by means of a polar modulator, and transmits the RF signal.

Abstract: A method, apparatus and storage mediums executed by a computer and storing the method, for expanding cell coverage in mobile communication system is disclosed. The method comprises the steps of: a) shifting a preamble window by delaying a transmission signal in order to catch a first call access signal from a mobile station at a remote distance; and b) delaying a second call access signal from a mobile station at a short distance in order to catch the second call access signal.