In this paper,a sliding mode observer scheme of sensor fault diagnosis is proposed for a class of time delay nonlinear systems with input uncertainty based on neural network.The sensor fault and the system input uncer...In this paper,a sliding mode observer scheme of sensor fault diagnosis is proposed for a class of time delay nonlinear systems with input uncertainty based on neural network.The sensor fault and the system input uncertainty are assumed to be unknown but bounded.The radial basis function (RBF) neural network is used to approximate the sensor fault.Based on the output of the RBF neural network,the sliding mode observer is presented.Using the Lyapunov method,a criterion for stability is given in terms of matrix inequality.Finally,an example is given for illustrating the availability of the fault diagnosis based on the proposed sliding mode observer.展开更多
A new time-resolved shifted dual transmission grating spectrometer （SDTGS） is designed and fabricated in this work. This SDTGS uses a new shifted dual transmission grating （SDTG） as its dispersive component, which...A new time-resolved shifted dual transmission grating spectrometer （SDTGS） is designed and fabricated in this work. This SDTGS uses a new shifted dual transmission grating （SDTG） as its dispersive component, which has two sub transmission gratings with different line densities, of 2000 lines/mm and 5000 lines/mm. The axes of the two sub transmission gratings in SDTG are horizontally and vertically shifted a certain distance to measure a broad range of 0.1-5 keV time-resolved X-ray spectra. The SDTG has been calibrated with a soft X-ray beam of the synchrotron radiation facility and its diffraction efficiency is also measured. The designed SDTGS can take full use of the space on a record panel and improve the precision for measuring spatial and temporal spectrum simultaneously. It will be a promising application for accurate diagnosis of the soft X-ray spectrum in inertial confinement fusion.展开更多
A new approach is advanced based on wavelet transform in tandem with autoregressive technique. Wavelets and wavelet packets decompose dynamic signal into different bands and pro- vide multiresolution or multiscale vie...A new approach is advanced based on wavelet transform in tandem with autoregressive technique. Wavelets and wavelet packets decompose dynamic signal into different bands and pro- vide multiresolution or multiscale view of signal. Autoregressive technique possesses effective function for short data processing. The approach is abopted to analyse nonstationary vibration sig- nals of mining excavator. The results indicate that nonstationary operating condition can be moni- tored and diagnosed. Transient toothmeshing frequency and rotating speed are measured. Weak vibration signal of defective ball bearing is extracted from strong vibration of gearbox and diag- nosed successfully. This approach is effective for nonstationary condition monitoring and early di- agnosis of latent fault.展开更多
With the increasing incidence and mortality of fungal infection, the requirements for strict diagnostic approaches became a very urgent issue. Because of the traditional detective techniques, such as culture, gave poo...With the increasing incidence and mortality of fungal infection, the requirements for strict diagnostic approaches became a very urgent issue. Because of the traditional detective techniques, such as culture, gave poor diagnostic outcomes, the molecular biological techniques are expected to develop the potential diagnostic approaches. During the past decades, we have carried out serial studies on the molecular properties of pathogenic fungi, and we would like to review as following. Firstly, we applied several molecular tools in classification and identification of pathogenic fungi. We performed random amplification of polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP) and other techniques in studying the typing, to classify and identify the properties of Dermatophytes, Candida spp., Crypotococcus neoformans, Dematiaceous fungi, and Aspergillus spp. Interestingly, we found the same T. rubrum strain might infect different sites of the host, while a site-specificity displayed in T. mentagrophytes. This finding indicated the genetic discrepancies among the fungi. Beside, we also found that the E. dermatitis strains with different virulences possessed some discrepancies at gene level. We then developed a PCR-based molecular procedure to identify the novel species in Exaphiala spp. As the applicable strategy, we also investigated the rDNA sequence properties in several fungi. And as a result, we submitted for the first time to GenBank the complete sequence of Aspergillus fumigatus rDNA/ITSI/ITSII, which provided the basis for designing the species-specific probes and for its further clinical applications. Secondly, we have tried to develop the molecular diagnostic approaches based on our DNA sequence data which were used for identification studies previously. By analyzing the DNA sequence of Aspergillus fumigatus rDNA/ITSI/ITSII, we developed a nested PCR method to detect Aspergillus fumigatus genes. Our preliminary results indicated that this PCR-based molecular approach has great importance in the diagnosis of invasive aspergillosis. We also designed the species-specific probes and then established several in situ hybridization procedures. We found these hybridization methods could get the positive rate up to 81% (13/16), which suggests that these methods have potential diagnostic value for invasive candidiasis and aspergillosis. Based on our experiences, we would conclude that the molecular biological techniques possess great value to investigate the biological properties of pathogenic fungi,and we are looking forward to see more and more molecular tools will be used in the pathogenic mechanisms of fungal infections and antifungal activity studies.展开更多
基金Natural Science Foundation of Jiangsu Province (No.SBK20082815)Aeronautical Science Foundation of China (No.20075152014)
文摘In this paper,a sliding mode observer scheme of sensor fault diagnosis is proposed for a class of time delay nonlinear systems with input uncertainty based on neural network.The sensor fault and the system input uncertainty are assumed to be unknown but bounded.The radial basis function (RBF) neural network is used to approximate the sensor fault.Based on the output of the RBF neural network,the sliding mode observer is presented.Using the Lyapunov method,a criterion for stability is given in terms of matrix inequality.Finally,an example is given for illustrating the availability of the fault diagnosis based on the proposed sliding mode observer.
基金supported by National Natural Science Foundation of China(Nos.11405158 and 11435011)Development Foundation of China Academy of Engineering Physics(Nos.2014B0102011 and 2014B0102012)
文摘A new time-resolved shifted dual transmission grating spectrometer （SDTGS） is designed and fabricated in this work. This SDTGS uses a new shifted dual transmission grating （SDTG） as its dispersive component, which has two sub transmission gratings with different line densities, of 2000 lines/mm and 5000 lines/mm. The axes of the two sub transmission gratings in SDTG are horizontally and vertically shifted a certain distance to measure a broad range of 0.1-5 keV time-resolved X-ray spectra. The SDTG has been calibrated with a soft X-ray beam of the synchrotron radiation facility and its diffraction efficiency is also measured. The designed SDTGS can take full use of the space on a record panel and improve the precision for measuring spatial and temporal spectrum simultaneously. It will be a promising application for accurate diagnosis of the soft X-ray spectrum in inertial confinement fusion.
文摘A new approach is advanced based on wavelet transform in tandem with autoregressive technique. Wavelets and wavelet packets decompose dynamic signal into different bands and pro- vide multiresolution or multiscale view of signal. Autoregressive technique possesses effective function for short data processing. The approach is abopted to analyse nonstationary vibration sig- nals of mining excavator. The results indicate that nonstationary operating condition can be moni- tored and diagnosed. Transient toothmeshing frequency and rotating speed are measured. Weak vibration signal of defective ball bearing is extracted from strong vibration of gearbox and diag- nosed successfully. This approach is effective for nonstationary condition monitoring and early di- agnosis of latent fault.
文摘With the increasing incidence and mortality of fungal infection, the requirements for strict diagnostic approaches became a very urgent issue. Because of the traditional detective techniques, such as culture, gave poor diagnostic outcomes, the molecular biological techniques are expected to develop the potential diagnostic approaches. During the past decades, we have carried out serial studies on the molecular properties of pathogenic fungi, and we would like to review as following. Firstly, we applied several molecular tools in classification and identification of pathogenic fungi. We performed random amplification of polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP) and other techniques in studying the typing, to classify and identify the properties of Dermatophytes, Candida spp., Crypotococcus neoformans, Dematiaceous fungi, and Aspergillus spp. Interestingly, we found the same T. rubrum strain might infect different sites of the host, while a site-specificity displayed in T. mentagrophytes. This finding indicated the genetic discrepancies among the fungi. Beside, we also found that the E. dermatitis strains with different virulences possessed some discrepancies at gene level. We then developed a PCR-based molecular procedure to identify the novel species in Exaphiala spp. As the applicable strategy, we also investigated the rDNA sequence properties in several fungi. And as a result, we submitted for the first time to GenBank the complete sequence of Aspergillus fumigatus rDNA/ITSI/ITSII, which provided the basis for designing the species-specific probes and for its further clinical applications. Secondly, we have tried to develop the molecular diagnostic approaches based on our DNA sequence data which were used for identification studies previously. By analyzing the DNA sequence of Aspergillus fumigatus rDNA/ITSI/ITSII, we developed a nested PCR method to detect Aspergillus fumigatus genes. Our preliminary results indicated that this PCR-based molecular approach has great importance in the diagnosis of invasive aspergillosis. We also designed the species-specific probes and then established several in situ hybridization procedures. We found these hybridization methods could get the positive rate up to 81% (13/16), which suggests that these methods have potential diagnostic value for invasive candidiasis and aspergillosis. Based on our experiences, we would conclude that the molecular biological techniques possess great value to investigate the biological properties of pathogenic fungi,and we are looking forward to see more and more molecular tools will be used in the pathogenic mechanisms of fungal infections and antifungal activity studies.
