摘要:
A storage file format for replaying an adaptively streamed multimedia stream, a client apparatus using the storage file format, and a method of storing a multimedia stream in the client apparatus are provided. According to the storage file format, meta-information for playing fragments and fragment access meta-information for replaying fragments are added to fragments.
摘要:
A radio over fiber (ROF) link apparatus capable of a stable TDD wireless service for a time division duplexing (TDD) baseband signal includes a central access platform (CAP) for receiving various kinds of data including the TDD baseband signal from upper layers, multiplexing the data, electro-optically converting the multiplexed data, and transmitting the converted data as downstream data through an optical fiber, and opto-electrically converting upstream data received through the optical fiber, demultiplexing the converted upstream data, and transmitting the demultiplexed upstream data to the respective upper layers, and a remote access unit (RAU) for receiving the downstream data through the optical fiber, opto-electrically converting the received downstream data to the multiplexed data, demultiplexing the multiplexed data, performing a wireless access process of the demultiplexed data, and transmitting the wireless access processed data to a wireless local area network (WLAN) service terminal through an antenna.
摘要:
Disclosed is a method for detecting a scene change in real time in order to control a moving-picture encoding data rate, the method including: dividing a current frame into a plurality of regions, and calculating a dissimilarity metric (DM) of each divided region; determining if the dissimilarity metric of each divided region is beyond a preset reference value; calculating the number of regions, the dissimilarity metric of which is beyond the preset value, in the current frame; and determining that a scene change occurs in the current frame, when the number of regions, the dissimilarity metric of which is beyond the reference preset value, is equal to or greater than a preset threshold value.
摘要:
Disclosed is a method for controlling bit rates in consideration of wireless channel environment by an apparatus that transmits and receives moving picture encoding data via a wireless network. The apparatus for transmitting/receiving data through a wireless communication network connected to the apparatus including a channel state analyzing unit for analyzing a wireless channel environment, an encoding controller for generating control information containing information about a quantization parameter, skip or non-skip of frames indication, frame type indication, and use or non-use of an Error Resilient Tool (ERT) indication, in consideration of an analyzation result received from the channel state analyzing unit, a moving picture encoding unit for encoding incoming moving picture data, based on the control information received from the encoding controller; and a data transmitting/receiving unit for transferring the encoded moving picture data through the wireless channel to an exterior.
摘要:
The present invention relates to a multi fixed-point cell for calibrating a thermometer and a thermometer calibration apparatus using the same, wherein measuring errors can be checked by using a property of constant temperature of a metal on the basis of a phase transition and wide range of temperature region can be measured by one time calibration, thereby capable of increasing efficiencies of time and cost which are taken for calibration. In a multi fixed-point cell for calibrating a thermometer according to the present invention, a thermometer inserting hole in which a thermometer is inserted is formed at one side and at least two reference material inserting holes in which reference materials having different phase transition temperatures are inserted respectively are formed on a same plane as that of the thermometer inserting hole so as to be spaced apart each other.
摘要:
Disclosed is a radio-over-fiber (ROF) system for supporting various services, the system comprising: a central access platform (CAP) for providing time division duplexing (TDD), frequency division duplexing (FDD), and broadcasting services, converting a TDD downward signal and FDD/broadcasting downward signals into optical signals, respectively, transmitting the converted optical signals to a remote access unit (RAU), converting a TDD upward signal and an FDD upward signal, which have been transmitted as optical signals from the RAU, into electric signals, respectively, and using an optical circulator in order to separate upward and downward signals from each other; and the RAU for converting the TDD downward signal and FDD/broadcasting downward signals transmitted from the CAP into electric signals, respectively, converting the TDD upward signal and FDD upward signal to be transmitted to the CAP into optical signals, respectively, and using an optical circulator in order to separate upward and downward signals from each other, wherein the RAU includes a plurality of signal filtering/separating/combining units, which wirelessly emit the TDD downward signal and FDD/broadcasting downward signals, having been converted into electric signals, through an antenna, and which separate wirelessly-received TDD upward signal and FDD upward signal from each other.
摘要:
An optical transmitter for generating return-to-zero alternative-mark-inversion (RZ-AMI) optical signals and a method for generating the optical signals are provided. The optical transmitter includes a light source radiating at its output an intensity-modulated light beam based upon intensity of a first data, a precoder for precoding a second data having the information identical to the first data, and a Mach Zehnder modulator for phase-modulating the intensity-modulated light on basis of the precoded second data to generate a return-to-zero alternative-mark-inversion (RZ-AMI) optical signal.
摘要:
A high temperature platinum resistance thermometer and a method of producing such a thermometer. Both a sensor frame and a protective tube are made of mon-crystalline synthetic sapphire, which has a melting point of about 2050.degree. C. and effectively prevents vaporized metal from transmitting through it. The thermometer is thus effectively operated at a high temperature up to about 1500.degree. C. The thermometer is also provided with platinum wires capable of measuring insulating resistance, thus effectively compensating for measuring errors caused by such an insulating resistance.
摘要:
A thermoelectric refrigerator/warmer using no external power, and a refrigerating/warming method are disclosed. A natural energy such as the solar energy is utilized so as to make an external power needless. Thus a thermoelectric device is made to convert the natural energy into electric power based on the difference between the internal and external temperatures, and this electric energy is converted again into a thermal energy by means of a peltier device, thereby varying the internal temperature of the apparatus. An outer part 4 of a thermoelectric device 3 is attached on the side face of the refrigerator/warmer, and an inner part 5 of it is attached on a bottom plate 7 of the refrigerator/warmer. Thus a thermoelectromotive force is generated based on the temperature difference between outside and inside of the refrigerator/warmer. The voltage thus generated is supplied to a peltier device 6 to cool or heat the bottom plate 7. In this manner, the thermoelectric refrigerator/warmer can be operated even without using an external power.
摘要:
Disclosed is a data transmission method for an MBS in a broadband wireless access system. The method includes the steps of constructing a Wibro frame by adding an FEC zone to a downlink portion of the Wibro frame by a radio access station, the FEC zone containing an FEC packet for performing a packet-based FEC scheme; and transmitting data to a plurality of mobile stations by the radio access station, the Wibro frame constructing the data.