Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular...Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular LDPC codes with Unequal Error Protection (UEP)property is designed in this letter. Simulation results show that the transmission quality of the image may be effectively improved with this class of irregular LDPC code.展开更多
The overvoltage phenomena of ultra high voltage (UHV) transmission lines are analyzed and verified by EMTDC/PSCAD simulation. Referring to the theoretical analyses and operating experiences of extra high voltage (EHV)...The overvoltage phenomena of ultra high voltage (UHV) transmission lines are analyzed and verified by EMTDC/PSCAD simulation. Referring to the theoretical analyses and operating experiences of extra high voltage (EHV) transmission lines in China and UHV transmission lines in Russia and Japan, the methods to suppress the internal overvoltage in UHV transmission lines by protection and control strategies are discussed. Through the cooperation among the recloser, shunt reactor, tripping and closing resistance, and metal oxide varistor(MOV), the overvoltage can be restrained within an acceptable level.展开更多
文摘Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular LDPC codes with Unequal Error Protection (UEP)property is designed in this letter. Simulation results show that the transmission quality of the image may be effectively improved with this class of irregular LDPC code.
基金ABB (China) Research Ltd. and National Natural Science Foundation of China(No.50477037)
文摘The overvoltage phenomena of ultra high voltage (UHV) transmission lines are analyzed and verified by EMTDC/PSCAD simulation. Referring to the theoretical analyses and operating experiences of extra high voltage (EHV) transmission lines in China and UHV transmission lines in Russia and Japan, the methods to suppress the internal overvoltage in UHV transmission lines by protection and control strategies are discussed. Through the cooperation among the recloser, shunt reactor, tripping and closing resistance, and metal oxide varistor(MOV), the overvoltage can be restrained within an acceptable level.