In spite of continuous research efforts directed at early detection and treatment of pancreatic cancer, the outlook for patients affected by the disease remains dismal. With most cases still being diagnosed at advance...In spite of continuous research efforts directed at early detection and treatment of pancreatic cancer, the outlook for patients affected by the disease remains dismal. With most cases still being diagnosed at advanced stages, no improvement in survival prognosis is achieved with current diagnostic imaging approaches. In the absence of a dominant precancerous condition, several risk factors have been identified including family history, chronic pancreatitis, smoking, diabetes mellitus, as well as certain genetic disorders such as hereditary pancreatitis, cystic fibrosis, familial atypical multiple mole melanoma, and Peutz-Jeghers and Lynch syn- dromes. Most pancreatic carcinomas, however, remain sporadic. Current progress in experimental molecular techniques has enabled detailed understanding of the molecular processes of pancreatic cancer development. According to the latest information, malignant pancre- atic transformation involves multiple oncogenes and tumor-suppressor genes that are involved in a variety of signaling pathways. The most characteristic aberrations （somatic point mutations and allelic losses） affect onco- genes and tumor-suppressor genes within RAS, AK-I- and Wnt signaling, and have a key role in transcription and proliferation, as well as systems that regulate the cell cycle （SMAD/DPC, CDKN2A/p16） and apoptosis （TP53）. Understanding of the underlying molecular mechanisms should promote development of new methodology for early diagnosis and facilitate improvement in current approaches for pancreatic cancer treatment.展开更多
In order to enhance communication reliability of differential frequency hopping system, a receiver implemented with the concatenation of an optimal subblock-by-subblock maximum a posteriori probability (OBB-MAP) detec...In order to enhance communication reliability of differential frequency hopping system, a receiver implemented with the concatenation of an optimal subblock-by-subblock maximum a posteriori probability (OBB-MAP) detector and a soft-decision Turbo decoder is proposed and validated in both AWGN and Rayleigh flat fading channels. It is shown that the OBB-MAP decoder can iteratively decode a cyclic trellis, and back-search the trellis for any state to obtain estimates for the prior information bits which can be employed by soft-decision Turbo decoder. The proposed receiver achieves a better bit error rate(BER) performance than maximum likelihood sequence estimation(MLSE) detector employing Viterbi algorithm. The simulation results demonstrate that the combined signal detection method improves communication quality.展开更多
A relevance vector machine (RVM) based fault diagnosis method was presented for non-linear circuits. In order to simplify RVM classifier, parameters selection based on particle swarm optimization (PSO) and preprocessi...A relevance vector machine (RVM) based fault diagnosis method was presented for non-linear circuits. In order to simplify RVM classifier, parameters selection based on particle swarm optimization (PSO) and preprocessing technique based on the kurtosis and entropy of signals were used. Firstly, sinusoidal inputs with different frequencies were applied to the circuit under test (CUT). Then, the resulting frequency responses were sampled to generate features. The frequency response was sampled to compute its kurtosis and entropy, which can show the information capacity of signal. By analyzing the output signals, the proposed method can detect and identify faulty components in circuits. The results indicate that the fault classes can be classified correctly for at least 99% of the test data in example circuit. And the proposed method can diagnose hard and soft faults.展开更多
文摘In spite of continuous research efforts directed at early detection and treatment of pancreatic cancer, the outlook for patients affected by the disease remains dismal. With most cases still being diagnosed at advanced stages, no improvement in survival prognosis is achieved with current diagnostic imaging approaches. In the absence of a dominant precancerous condition, several risk factors have been identified including family history, chronic pancreatitis, smoking, diabetes mellitus, as well as certain genetic disorders such as hereditary pancreatitis, cystic fibrosis, familial atypical multiple mole melanoma, and Peutz-Jeghers and Lynch syn- dromes. Most pancreatic carcinomas, however, remain sporadic. Current progress in experimental molecular techniques has enabled detailed understanding of the molecular processes of pancreatic cancer development. According to the latest information, malignant pancre- atic transformation involves multiple oncogenes and tumor-suppressor genes that are involved in a variety of signaling pathways. The most characteristic aberrations （somatic point mutations and allelic losses） affect onco- genes and tumor-suppressor genes within RAS, AK-I- and Wnt signaling, and have a key role in transcription and proliferation, as well as systems that regulate the cell cycle （SMAD/DPC, CDKN2A/p16） and apoptosis （TP53）. Understanding of the underlying molecular mechanisms should promote development of new methodology for early diagnosis and facilitate improvement in current approaches for pancreatic cancer treatment.
文摘In order to enhance communication reliability of differential frequency hopping system, a receiver implemented with the concatenation of an optimal subblock-by-subblock maximum a posteriori probability (OBB-MAP) detector and a soft-decision Turbo decoder is proposed and validated in both AWGN and Rayleigh flat fading channels. It is shown that the OBB-MAP decoder can iteratively decode a cyclic trellis, and back-search the trellis for any state to obtain estimates for the prior information bits which can be employed by soft-decision Turbo decoder. The proposed receiver achieves a better bit error rate(BER) performance than maximum likelihood sequence estimation(MLSE) detector employing Viterbi algorithm. The simulation results demonstrate that the combined signal detection method improves communication quality.
基金Project(Z132012)supported by the Second Five Technology-based in Science and Industry Bureau of ChinaProject(YWF1103Q062)supported by the Fundemental Research Funds for the Central Universities in China
文摘A relevance vector machine (RVM) based fault diagnosis method was presented for non-linear circuits. In order to simplify RVM classifier, parameters selection based on particle swarm optimization (PSO) and preprocessing technique based on the kurtosis and entropy of signals were used. Firstly, sinusoidal inputs with different frequencies were applied to the circuit under test (CUT). Then, the resulting frequency responses were sampled to generate features. The frequency response was sampled to compute its kurtosis and entropy, which can show the information capacity of signal. By analyzing the output signals, the proposed method can detect and identify faulty components in circuits. The results indicate that the fault classes can be classified correctly for at least 99% of the test data in example circuit. And the proposed method can diagnose hard and soft faults.
