In this paper,we present a method of wavelet estimation by matching well-log, VSP,and surface-seismic data.It＇s based on a statistical model in which both input and output are contaminated with additive random noise....In this paper,we present a method of wavelet estimation by matching well-log, VSP,and surface-seismic data.It＇s based on a statistical model in which both input and output are contaminated with additive random noise.A coherency matching technique is used to estimate the wavelet.Measurements of goodness-of-fit and accuracy provide tools for quality control.A practical example suggests that our method is robust and stable.The matching and estimation of the wavelet is reliable within the seismic bandwidth.This method needs no assumption on the wavelet amplitude and phase and the main advantage of the method is its ability to determine phase.展开更多
Objective To study the value of ultrasound elastography in evaluation of ethanol-induced lesions of liver. Methods Alcohol with a dose of 2 ml was injected into a fresh porcine liver under ultrasound guidance to creat...Objective To study the value of ultrasound elastography in evaluation of ethanol-induced lesions of liver. Methods Alcohol with a dose of 2 ml was injected into a fresh porcine liver under ultrasound guidance to create stiff necrosis. Then freehand elastography of the lesion from the identical scan plane was obtained with SONOLINE Antares system using VF10-5 probe at about every 30 seconds till 6 minutes later. The original high quality radiofrequency data were acquired through an ultrasound research interface which was provided by the ultrasound system. Then, corresponding elastograms were produced offline using cross-correlation technique and compared with gross pathology findings. Results Gray-scale sonogram showed a hyperechoic area with acoustic shadow below appeared immediately after alcohol injection. The hyperechoic area tended to be diffuse and its boundary to be illegible with time. On the contrary, the ethanol-induced lesion in elastogram appeared as a low swain hard region surrounded by high strain soft hepatic tissues, with clear but irregular boundaries. Sequential elastograms with the sketched lesion boundaries showed that the lesion area increased in the first 3 minutes after ethanol injection, and then reached a plateau which corresponding to gross specimen. Conclusion Ultrasound elastography is capable of detecting and evaluating the diffusion of ethanol-induced hepatic lesion, and more sensitive and accurate than routine sonography.展开更多
This paper explores the image of the body in physically dependent elderly men and women and the way in which this image reconfigures their identity creating new meanings. In old age, the body becomes related with illn...This paper explores the image of the body in physically dependent elderly men and women and the way in which this image reconfigures their identity creating new meanings. In old age, the body becomes related with illness, with disablement and with its own material finiteness. Representations of the body are thus constructed around pain, deficiency, and fragility. The research was carried out from a qualitative perspective, performing in-depth interviews, with participant observation and a subject ID card as data collecting techniques. The identity of the interviewees who consented to be recorded was protected. The data were analyzed constructing concepts and theoretical and empirical categories with the support of the Etnograph V.5 software for qualitative data. The findings reflect discourses on the body that turn on its deterioration and limitations that prevent old people from functioning adequately in life. Metaphors were identified telling of a sense of＂deteriorated identity＂; most participants saw themselves as ＂a burden＂. They also showed symptoms of annoyance and shame regarding their sick or fragile bodies, as well as a constant memory of the healthy or ＂ideal＂ body of the past, which is hegemonic in our culture.展开更多
基金the Natural Science Foundation of China(Grant Nos.40974066 and 40821062)by the National Basic Research Program of China(Grant No.2007CB209602).
文摘In this paper,we present a method of wavelet estimation by matching well-log, VSP,and surface-seismic data.It＇s based on a statistical model in which both input and output are contaminated with additive random noise.A coherency matching technique is used to estimate the wavelet.Measurements of goodness-of-fit and accuracy provide tools for quality control.A practical example suggests that our method is robust and stable.The matching and estimation of the wavelet is reliable within the seismic bandwidth.This method needs no assumption on the wavelet amplitude and phase and the main advantage of the method is its ability to determine phase.
基金Supported by National Natural Science Foundation of China (30470466)
文摘Objective To study the value of ultrasound elastography in evaluation of ethanol-induced lesions of liver. Methods Alcohol with a dose of 2 ml was injected into a fresh porcine liver under ultrasound guidance to create stiff necrosis. Then freehand elastography of the lesion from the identical scan plane was obtained with SONOLINE Antares system using VF10-5 probe at about every 30 seconds till 6 minutes later. The original high quality radiofrequency data were acquired through an ultrasound research interface which was provided by the ultrasound system. Then, corresponding elastograms were produced offline using cross-correlation technique and compared with gross pathology findings. Results Gray-scale sonogram showed a hyperechoic area with acoustic shadow below appeared immediately after alcohol injection. The hyperechoic area tended to be diffuse and its boundary to be illegible with time. On the contrary, the ethanol-induced lesion in elastogram appeared as a low swain hard region surrounded by high strain soft hepatic tissues, with clear but irregular boundaries. Sequential elastograms with the sketched lesion boundaries showed that the lesion area increased in the first 3 minutes after ethanol injection, and then reached a plateau which corresponding to gross specimen. Conclusion Ultrasound elastography is capable of detecting and evaluating the diffusion of ethanol-induced hepatic lesion, and more sensitive and accurate than routine sonography.
文摘This paper explores the image of the body in physically dependent elderly men and women and the way in which this image reconfigures their identity creating new meanings. In old age, the body becomes related with illness, with disablement and with its own material finiteness. Representations of the body are thus constructed around pain, deficiency, and fragility. The research was carried out from a qualitative perspective, performing in-depth interviews, with participant observation and a subject ID card as data collecting techniques. The identity of the interviewees who consented to be recorded was protected. The data were analyzed constructing concepts and theoretical and empirical categories with the support of the Etnograph V.5 software for qualitative data. The findings reflect discourses on the body that turn on its deterioration and limitations that prevent old people from functioning adequately in life. Metaphors were identified telling of a sense of＂deteriorated identity＂; most participants saw themselves as ＂a burden＂. They also showed symptoms of annoyance and shame regarding their sick or fragile bodies, as well as a constant memory of the healthy or ＂ideal＂ body of the past, which is hegemonic in our culture.
