Abstract: An image projection device includes: a panel unit configured to emit light rays; a projection optical system configured to receive the light rays emitted from the panel unit and to refract the light rays; a reflection unit having a reflection surface for receiving the light rays refracted by the projection optical system and reflecting the light rays; and a screen unit configured to display an image upon receiving the light rays reflected from the reflection surface. The panel unit, the projection optical system, the reflection unit, and the screen unit are arranged such that a distance of a shortest path among paths extending from the panel unit to the reflection unit through the projection optical system along a predetermined linear axis is longer than a distance of a longest path among paths extending from the reflection unit to the screen unit along the predetermined linear axis.

Abstract: An image projection device includes: a panel unit configured to emit light rays; a projection optical system configured to receive the light rays emitted from the panel unit and to refract the light rays; a reflection unit having a reflection surface for receiving the light rays refracted by the projection optical system and reflecting the light rays; and a screen unit configured to display an image upon receiving the light rays reflected from the reflection surface. The panel unit, the projection optical system, the reflection unit, and the screen unit are arranged such that a distance of a shortest path among paths extending from the panel unit to the reflection unit through the projection optical system along a predetermined linear axis is longer than a distance of a longest path among paths extending from the reflection unit to the screen unit along the predetermined linear axis.

Abstract: Provided is a system and method for a local area broadcast service, and a wireless transmission apparatus applied to them. In the system, contents to be broadcasted in a predetermined local area are transmitted from a broadcast server to a wireless transmission apparatus through a wired network based on an Internet Protocol and the contents are then broadcasted from the wireless transmission apparatus to one or more user terminal devices. Therefore, according to the present invention, a server of a wired network can easily provide particular contents for each particular local area to one or more user terminal devices in the local area. Moreover, it is possible to reduce the load of the server, when the server provides multiple types of contents or provides contents to a plurality of user terminal devices.

Abstract: Disclosed is a multicast system and a multicast method using a shortened address and an apparatus applied to the same. The multicast system using the shortened address according to the present disclosure has a address configuration for supporting a multicast in an IEEE 802.15.4 MAC (Medium Access Control) layer. Accordingly, when a device processes a multicast through an address configuration of the MAC layer, the device receives the multicast through a simple scheduling such as receiving a beacon signal of a coordinator device only when there is a broadcast of a group including the device. As a result, the device can efficiently perform the multicast in a power managing process or a power processing process.

Abstract: Provided is a synchronization system and method for acoustic communication in audible frequency range, and an apparatus applied thereto. The synchronization system for acoustic communication in audible frequency range is configured to prevent deterioration of a synchronization performance and to reduce an amount of calculation by calculating a correlation based on a few samples as opposed to calculating a correlation for each sample when a receiver of the acoustic communication performs synchronization while the acoustic communication is performed in the audible frequency range through modification of an audio signal or adding of a predetermined signal to an audio signal.

Abstract: The present invention relates to a method and to a wireless personal area network (WPAN) device in which the device sets the beacon slot in the WPAN device and receives beacon slot information from neighbor devices, while setting the beacon table of the devices, to avoid the transmission time of the neighbor devices and the transmission time of the devices neighboring the neighbor devices in a WPAN. In the method, beacon message, including information about neighbors' transmission time and information about neighbors' neighbors' transmission time, is received from neighbor devices. The beacon message is combined, and the neighbors' transmission time information and the neighbors' neighbors' transmission time information are input into a beacon table. The neighbors' transmission time and the neighbors' neighbors' transmission time are input into a field for BTTSs to be avoided in the beacon table.

Abstract: Disclosed is a network interworking system and method. That is, a header size is minimized through a fragment of an IPv4 packet based IP packet and a header compression and it is implemented such that the IPv4 is loaded in an IEEE 802.15.4 MAC/PHY packet having a small payload, so that it is possible to efficiently transmit an IPv4 packet by using an IEEE 802.15.4 based WPAN. Further, various applications can be executed using the IPv4 while using an IEEE 802.15.4 technology, which is a low power communication technology, in a mobile device.

Abstract: Disclosed is a system and a method for minimizing signal interference for a broadcasting and communication convergence section within a local area, and an apparatus applied to the same. The system has a construction of mounting a plurality of multi RF (Radio Frequency) channels within a local area wireless communication apparatus located in a local area and minimizing signal interference between mutually adjacent RF channels within the local area wireless communication apparatus in a standard for providing a broadcasting and communication convergence service. Accordingly, it is possible to remove the mutual channel effects affecting a communication signal without signal interference for adjacent channels due to a broadcasting signal and it is not necessary to enhance a filtering characteristic for the adjacent channels of a chipset, which corresponds to a broadcasting and communication convergence standard structure in a local area, so that there is an advantage of reducing network investment costs.

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: Provided is a data reception error reduction system and method in acoustic communication in audible frequency range, and an apparatus applied thereto. The data reception error reduction system in the acoustic communication in audible frequency range may be configured to reduce a data reception error in a receiver by taking into consideration that a sound signal is noisy and is significantly affected by a change in the ambient environment when the acoustic communication is performed in the audio frequency band through modification of an audio signal or adding of a predetermined signal to an audio signal. Accordingly, the data reception error may be reduced in the receiver even in an environment where a sound signal is noisy and is significantly affected by a change in the ambient environment, and reliability of data transmission may increase.

Abstract: Disclosed are an apparatus and a method for voice processing in a mobile communication terminal. A plurality of microphones are used to remove environmental noise at the time of voice communication, so that it is possible to perform high-quality voice communication and video telephony. Moreover, it is possible to perform voice recording even when a user does not open a mobile communication terminal. Furthermore, when voice is recorded or sound is recorded during moving image photographing, a plurality of microphones are effectively utilized to achieve good-quality recording and to perform recording conveniently even when the folder or the slider of the mobile communication terminal is closed. Therefore, it is possible to provide improved convenience in using the mobile communication terminal.

Abstract: A chip equalization apparatus and method for selecting cluster signals from broadcast signals being continuously received in multi-path channels for extracting a plurality of cluster signals from among the received broadcast signals and using a plurality of chip equalizers each having a tap coefficient update part for updating the tap coefficients of the selected cluster signals when the equalization outputs are combined to compensate the broadcast signals and provide low power consumption and efficient equalization for use in a satellite broadcasting receiving system.

Abstract: The present invention relates to a system and method for providing a supplementary information service related to broadcast content. The system for providing a supplementary information service related to broadcast content being broadcasted to user terminal comprises a Time Information Creating Server for Identifying a start time information of the broadcast content; and a Supplementary Information Service Providing Server for receiving the start time information of the broadcast content from the Time Information Creating Server, calculating elapsed time for a specific scene based on the start time information, and providing a user terminal with an supplementary information corresponding to the scene based on the elapsed time, through a communication network.

Abstract: Disclosed herein is a system and method for providing a supplementary information associated with a broadcast content. The system provides a supplementary information associated with a specific broadcast program in the broadcast content by means of a supplementary information server, wherein the supplementary information server comprises a broadcasting receiving unit for receiving the broadcast content; a synchronization information unit for storing a synchronization information of the supplementary information associated with the specific broadcast program; a video comparison unit for comparing screens of the broadcast content with a previously stored scene change screen of the specific broadcast program and setting a start time of the specific broadcast program; a supplementary information extracting unit for calculating an elapsed time from the start time of the specific broadcast program to a specific screen and extracting the supplementary information corresponding to the elapsed time.

Abstract: Disclosed is a method and system for estimating an adaptive joint channel in a CDMA system based on TDD. The method includes the steps of a) receiving activity information of a mobile terminal; b) parsing the activity information, and transmitting a midamble sequence to the mobile terminal when a result of the parsing shows that the mobile terminal is in an ON state; c) conducting adaptive joint channel estimation by using the midamble sequence in the mobile terminal; and d) conducting adaptive joint detection by using a channel impulse response of the mobile terminal, obtained as a result of conducting the adaptive joint channel estimation. The method and system decreases the complexity in channel estimation and additionally increases the accuracy of channel estimation by reducing transmission power consumption and eliminating unnecessary interference.

Abstract: Provided is a data reception error reduction system and method in acoustic communication in audible frequency range, and an apparatus applied thereto. The data reception error reduction system in the acoustic communication in audible frequency range may be configured to reduce a data reception error in a receiver by taking into consideration that a sound signal is noisy and is significantly affected by a change in the ambient environment when the acoustic communication is performed in the audio frequency band through modification of an audio signal or adding of a predetermined signal to an audio signal. Accordingly, the data reception error may be reduced in the receiver even in an environment where a sound signal is noisy and is significantly affected by a change in the ambient environment, and reliability of data transmission may increase.

Abstract: Provided is a synchronization system and method for acoustic communication in audible frequency range, and an apparatus applied thereto. The synchronization system for acoustic communication in audible frequency range is configured to prevent deterioration of a synchronization performance and to reduce an amount of calculation by calculating a correlation based on a few samples as opposed to calculating a correlation for each sample when a receiver of the acoustic communication performs synchronization while the acoustic communication is performed in the audible frequency range through modification of an audio signal or adding of a predetermined signal to an audio signal.

Abstract: Disclosed is a multicast system and a multicast method using a shortened address and an apparatus applied to the same. The multicast system using the shortened address according to the present disclosure has a address configuration for supporting a multicast in an IEEE 802.15.4 MAC (Medium Access Control) layer. Accordingly, when a device processes a multicast through an address configuration of the MAC layer, the device receives the multicast through a simple scheduling such as receiving a beacon signal of a coordinator device only when there is a broadcast of a group including the device. As a result, the device can efficiently perform the multicast in a power managing process or a power processing process.

Abstract: Disclosed is a network interworking system and method. That is, a header size is minimized through a fragment of an IPv4 packet based IP packet and a header compression and it is implemented such that the IPv4 is loaded in an IEEE 802.15.4 MAC/PHY packet having a small payload, so that it is possible to efficiently transmit an IPv4 packet by using an IEEE 802.15.4 based WPAN. Further, various applications can be executed using the IPv4 while using an IEEE 802.15.4 technology, which is a low power communication technology, in a mobile device.