The imaging and target detection methods for stepped frequency signal based on the wavelet transform and its power spectrum are investigated. Not only an imaging and target detection algorithm for stepped frequency si...The imaging and target detection methods for stepped frequency signal based on the wavelet transform and its power spectrum are investigated. Not only an imaging and target detection algorithm for stepped frequency signal based on the wavelet transform, but also its respective power spectrum are proposed. The multisampling property of stepped frequency signal is studied and wavelet transform is well suited for analyzing the signal. After multisampling property of stepped frequency signal being studied, it is shown that the wavelet transform is appropriate to analyze the signal. Based on the theory, the wavelet power spectrum analysis is applied to obtain the target range profile and the binary wavelet transform is used to perform target detection. To determine a suitable wavelet scaling for imaging of range profile's MMW radar, the distance resolution ΔR technique is proposed. The effectiveness of this new method is evaluated using simulated noisy radar signal. Results show that the proposed method can bring out the exactness and low computational complexity of this method.展开更多
In the construction process, the overall quality level of the building is mainly determined by the deep pit supporting construction. In order to further optimize the construction process and further improve the qualit...In the construction process, the overall quality level of the building is mainly determined by the deep pit supporting construction. In order to further optimize the construction process and further improve the quality level and ensure the safety, it is necessary to analyze the key points of the construction in detail. Strengthening the support construction of deep foundation pit can improve the overall quality level of the project and ensure the stability and prolong the service life of the building. Therefore, the construction industry must pay more attention to the construction technology of deep foundation pit support, and use more scientific methods to improve this technology more effectively, so that this technology can be widely popularized and used in the construction industry. In addition, although the deep foundation pit support technology has developed well, there will inevitably be some problems in the development process. The construction party should analyze and study these situations, and adjust the construction scheme according to some influencing factors to make it more reasonable, so as to ensure its accuracy and technical effectiveness.展开更多
Cobb syndrome, also known as cutaneo-meningospinal angiomatosis, is a rare clinical entity characterized by the combination of a vascular skin nevus and an angioma in the spinal canal at the same metamere. 1 It was f...Cobb syndrome, also known as cutaneo-meningospinal angiomatosis, is a rare clinical entity characterized by the combination of a vascular skin nevus and an angioma in the spinal canal at the same metamere. 1 It was first described by Berenbruch in 1890 and did not receive recognition until Cobb’s description 2 in 1915. Only few documents about this disease had been reported. 1 We present two cases here and review the other reported cases.展开更多
文摘The imaging and target detection methods for stepped frequency signal based on the wavelet transform and its power spectrum are investigated. Not only an imaging and target detection algorithm for stepped frequency signal based on the wavelet transform, but also its respective power spectrum are proposed. The multisampling property of stepped frequency signal is studied and wavelet transform is well suited for analyzing the signal. After multisampling property of stepped frequency signal being studied, it is shown that the wavelet transform is appropriate to analyze the signal. Based on the theory, the wavelet power spectrum analysis is applied to obtain the target range profile and the binary wavelet transform is used to perform target detection. To determine a suitable wavelet scaling for imaging of range profile's MMW radar, the distance resolution ΔR technique is proposed. The effectiveness of this new method is evaluated using simulated noisy radar signal. Results show that the proposed method can bring out the exactness and low computational complexity of this method.
文摘In the construction process, the overall quality level of the building is mainly determined by the deep pit supporting construction. In order to further optimize the construction process and further improve the quality level and ensure the safety, it is necessary to analyze the key points of the construction in detail. Strengthening the support construction of deep foundation pit can improve the overall quality level of the project and ensure the stability and prolong the service life of the building. Therefore, the construction industry must pay more attention to the construction technology of deep foundation pit support, and use more scientific methods to improve this technology more effectively, so that this technology can be widely popularized and used in the construction industry. In addition, although the deep foundation pit support technology has developed well, there will inevitably be some problems in the development process. The construction party should analyze and study these situations, and adjust the construction scheme according to some influencing factors to make it more reasonable, so as to ensure its accuracy and technical effectiveness.
文摘Cobb syndrome, also known as cutaneo-meningospinal angiomatosis, is a rare clinical entity characterized by the combination of a vascular skin nevus and an angioma in the spinal canal at the same metamere. 1 It was first described by Berenbruch in 1890 and did not receive recognition until Cobb’s description 2 in 1915. Only few documents about this disease had been reported. 1 We present two cases here and review the other reported cases.
