In the process of seismic data interpretation, the extraction of a horizon or a fault is generally needed. In this paper we present a fast extraction method. First select some feature points interactively, then recons...In the process of seismic data interpretation, the extraction of a horizon or a fault is generally needed. In this paper we present a fast extraction method. First select some feature points interactively, then reconstruct the surface according to the selected feature points by using B-spline interpolation curve or surface. In order to solve the error-drawing problem appeared in the process of interactive rendering, which is caused by the change of sampling interval as the view point changes, we combine shear-warp and splatting algorithm to render the surface. The rendering of seismic data and specific surface in our work are achieved on GPU platform using CUDA programming language, which make it able to meet the requirements of real-time rendering.展开更多
A principal direction Gaussian image （PDGI）-based algorithm is proposed to extract the regular swept surface from point cloud. Firstly, the PDGI of the regular swept surface is constructed from point cloud, then the...A principal direction Gaussian image （PDGI）-based algorithm is proposed to extract the regular swept surface from point cloud. Firstly, the PDGI of the regular swept surface is constructed from point cloud, then the bounding box of the Gaussian sphere is uniformly partitioned into a number of small cubes （3D grids） and the PDGI points on the Gaussian sphere are associated with the corresponding 3D grids. Secondly, cluster analysis technique is used to sort out a group of 3D grids containing more PDGI points among the 3D grids. By the connected-region growing algorithm, the congregation point or the great circle is detected from the 3D grids. Thus the translational direction is determined by the congregation point and the direction of the rotational axis is determined by the great circle. In addition, the positional point of the rotational axis is obtained by the intersection of all the projected normal lines of the rotational surface on the plane being perpendicular to the estimated direction of the rotational axis. Finally, a pattem search method is applied to optimize the translational direction and the rotational axis. Some experiments are used to illustrate the feasibility of the above algorithm.展开更多
AIM： To investigate the early changes in dry eye symptoms, tear function and ocular surface following small-incision lenticule extraction（SMILE） for myopia.·METHODS： Ninety-seven consecutive patients（193 eye...AIM： To investigate the early changes in dry eye symptoms, tear function and ocular surface following small-incision lenticule extraction（SMILE） for myopia.·METHODS： Ninety-seven consecutive patients（193 eyes）who underwent SMILE for myopia were observed in this longitudinal and retrospective study. Parameters evaluated included： subjective dry eye symptoms（dryness, foreign body sensation and photophobia）, tear film breakup time（TBUT）, Schirmer Ⅰ test without anesthesia（S Ⅰ T）, tear meniscus height（TMH） and corneal fluorescein staining. Each parameter was evaluated before, and subsequently at 1d, 1wk, 1 and3 mo after surgery.·RESULTS： Compared with preoperative data, dryness was noted to be significantly increased at 1wk and 1mo postoperatively（P 〈0.01）. Symptoms of photophobia and foreign body sensation demonstrated significant differences at 1d and 1wk as compared with preoperative scores respectively（P 〈0.01）. These values were decreased at 1 and 3mo post-surgery（P 〉0.05）.Conversely the corneal staining scores were higher than the preoperative data at 1d, 1wk and 1mo（P 〈0.01）, but were close to the preoperative level at 3mo postoperatively. There was a significant decrease in TMH at 1wk and 1mo（P 〈0.01）, but the value was close to the preoperative level at 3mo postoperatively（P =0.16）. The examination outcomes of S Ⅰ T were significantly increased at 1d then reduced at 1wk after surgery（P 〈0.01）. Each value subsequently returned to the baseline value at 1 and 3mo（P 〉0.05）. TBUT was significantly decreased at all postoperative time points（P 〈0.01）.· CONCLUSION： SMILE resulted in mild dry eye symptoms, tear film instability and ocular surface damages; however, these complications can recover in a short period of time.展开更多
Because of the developed economy and lush vegetation in southern China, the following obstacles or difficulties exist in remote sensing land surface classification: 1) Diverse surface composition types;2) Undulating t...Because of the developed economy and lush vegetation in southern China, the following obstacles or difficulties exist in remote sensing land surface classification: 1) Diverse surface composition types;2) Undulating terrains;3) Small fragmented land;4) Indistinguishable shadows of surface objects. It is our top priority to clarify how to use the concept of big data (Data mining technology) and various new technologies and methods to make complex surface remote sensing information extraction technology develop in the direction of automation, refinement and intelligence. In order to achieve the above research objectives, the paper takes the Gaofen-2 satellite data produced in China as the data source, and takes the complex surface remote sensing information extraction technology as the research object, and intelligently analyzes the remote sensing information of complex surface on the basis of completing the data collection and preprocessing. The specific extraction methods are as follows: 1) extraction research on fractal texture features of Brownian motion;2) extraction research on color features;3) extraction research on vegetation index;4) research on vectors and corresponding classification. In this paper, fractal texture features, color features, vegetation features and spectral features of remote sensing images are combined to form a combination feature vector, which improves the dimension of features, and the feature vector improves the difference of remote sensing features, and it is more conducive to the classification of remote sensing features, and thus it improves the classification accuracy of remote sensing images. It is suitable for remote sensing information extraction of complex surface in southern China. This method can be extended to complex surface area in the future.展开更多
A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region f...A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region from the rest of the input point cloud with the processes of sampling point data, estimation of local surface curvature properties and comparison of maximum curvature values. The recovery of parametric representation generates a set of profile curves by marching throughout the blend and fitting cylinders. Compared with the existing approaches of blend surface feature extraction, the proposed method reduces the requirement of user interaction and is capable of extracting blend surface with either constant radius or variable radius. Application examples are presented to verify the proposed method.展开更多
This is second paper summarizing the study on the hydrous titanium oxide absorbent for extracting uranium fromseawater. The investigation is performed by means of X- ray photoelectronic energy spectroscopy for chemica...This is second paper summarizing the study on the hydrous titanium oxide absorbent for extracting uranium fromseawater. The investigation is performed by means of X- ray photoelectronic energy spectroscopy for chemical analysis ( ESC A ) , determination of surface hydroxy radical, Fourier-transfer infrared spectrophotometry (FT-IR ) , electron paramagnetic resonance (EPR), inductively coupled Plasma torch (ICP), etc. The emphasis is laid upon the exploration of HTO surface and a discussion about the adsorption micromechanism.展开更多
In this contribution, we present an all-optical quantitative framework for bioluminescence tomography with non-contact measurement. The framework is comprised of four indispensable steps： extraction of the geometrica...In this contribution, we present an all-optical quantitative framework for bioluminescence tomography with non-contact measurement. The framework is comprised of four indispensable steps： extraction of the geometrical structures of the subject, light flux reconstruction on arbitrary surface, calibration and quantification of the surface light flux and internal bioluminescence reconstruction. In particular, the geometrical structures are retrieved using a completely optical method and captured under identical viewing conditions with the bioluminescent images. As a result, the proposed framework avoids the utilization of computed tomography or magnetic resonance imaging to provide the geometrical structures. On the basis of experimental measurements, we evaluate the performance of the proposed all-optical quantitative framework using a mouse shaped phantom. Preliminary result reveals the potential and feasibility of the proposed framework for bioluminescence tomography.展开更多
This paper focuses on entirety ioterpretation, representation and reconstruction of three-dimensional volume data sets based on the physical model of the data. The data model is represented by thIee-dimensional geomet...This paper focuses on entirety ioterpretation, representation and reconstruction of three-dimensional volume data sets based on the physical model of the data. The data model is represented by thIee-dimensional geometric model.The surfaces inside the datafield are extracted and matched to the model stirfaces in order to reconstruct the new datafield based on the model. A conclusion is drawn that physical modeling provides a good basis and approach to interpret and represellt the data sets. This paPer also presents a subdivision algorithm to fast traJce B-spline curve and the colltrary algorithm is adopted to extract the geometry feature of the curve.展开更多
文摘In the process of seismic data interpretation, the extraction of a horizon or a fault is generally needed. In this paper we present a fast extraction method. First select some feature points interactively, then reconstruct the surface according to the selected feature points by using B-spline interpolation curve or surface. In order to solve the error-drawing problem appeared in the process of interactive rendering, which is caused by the change of sampling interval as the view point changes, we combine shear-warp and splatting algorithm to render the surface. The rendering of seismic data and specific surface in our work are achieved on GPU platform using CUDA programming language, which make it able to meet the requirements of real-time rendering.
基金This project is supported by Key Program of National Natural Science Foundation of China(No.50435020).
文摘A principal direction Gaussian image （PDGI）-based algorithm is proposed to extract the regular swept surface from point cloud. Firstly, the PDGI of the regular swept surface is constructed from point cloud, then the bounding box of the Gaussian sphere is uniformly partitioned into a number of small cubes （3D grids） and the PDGI points on the Gaussian sphere are associated with the corresponding 3D grids. Secondly, cluster analysis technique is used to sort out a group of 3D grids containing more PDGI points among the 3D grids. By the connected-region growing algorithm, the congregation point or the great circle is detected from the 3D grids. Thus the translational direction is determined by the congregation point and the direction of the rotational axis is determined by the great circle. In addition, the positional point of the rotational axis is obtained by the intersection of all the projected normal lines of the rotational surface on the plane being perpendicular to the estimated direction of the rotational axis. Finally, a pattem search method is applied to optimize the translational direction and the rotational axis. Some experiments are used to illustrate the feasibility of the above algorithm.
基金Supported by Project of National Clinical Key Discipline of Chinese Ministry of Health,Zhejiang Key Laboratory Fund of China(No.2011E10006)
文摘AIM： To investigate the early changes in dry eye symptoms, tear function and ocular surface following small-incision lenticule extraction（SMILE） for myopia.·METHODS： Ninety-seven consecutive patients（193 eyes）who underwent SMILE for myopia were observed in this longitudinal and retrospective study. Parameters evaluated included： subjective dry eye symptoms（dryness, foreign body sensation and photophobia）, tear film breakup time（TBUT）, Schirmer Ⅰ test without anesthesia（S Ⅰ T）, tear meniscus height（TMH） and corneal fluorescein staining. Each parameter was evaluated before, and subsequently at 1d, 1wk, 1 and3 mo after surgery.·RESULTS： Compared with preoperative data, dryness was noted to be significantly increased at 1wk and 1mo postoperatively（P 〈0.01）. Symptoms of photophobia and foreign body sensation demonstrated significant differences at 1d and 1wk as compared with preoperative scores respectively（P 〈0.01）. These values were decreased at 1 and 3mo post-surgery（P 〉0.05）.Conversely the corneal staining scores were higher than the preoperative data at 1d, 1wk and 1mo（P 〈0.01）, but were close to the preoperative level at 3mo postoperatively. There was a significant decrease in TMH at 1wk and 1mo（P 〈0.01）, but the value was close to the preoperative level at 3mo postoperatively（P =0.16）. The examination outcomes of S Ⅰ T were significantly increased at 1d then reduced at 1wk after surgery（P 〈0.01）. Each value subsequently returned to the baseline value at 1 and 3mo（P 〉0.05）. TBUT was significantly decreased at all postoperative time points（P 〈0.01）.· CONCLUSION： SMILE resulted in mild dry eye symptoms, tear film instability and ocular surface damages; however, these complications can recover in a short period of time.
文摘Because of the developed economy and lush vegetation in southern China, the following obstacles or difficulties exist in remote sensing land surface classification: 1) Diverse surface composition types;2) Undulating terrains;3) Small fragmented land;4) Indistinguishable shadows of surface objects. It is our top priority to clarify how to use the concept of big data (Data mining technology) and various new technologies and methods to make complex surface remote sensing information extraction technology develop in the direction of automation, refinement and intelligence. In order to achieve the above research objectives, the paper takes the Gaofen-2 satellite data produced in China as the data source, and takes the complex surface remote sensing information extraction technology as the research object, and intelligently analyzes the remote sensing information of complex surface on the basis of completing the data collection and preprocessing. The specific extraction methods are as follows: 1) extraction research on fractal texture features of Brownian motion;2) extraction research on color features;3) extraction research on vegetation index;4) research on vectors and corresponding classification. In this paper, fractal texture features, color features, vegetation features and spectral features of remote sensing images are combined to form a combination feature vector, which improves the dimension of features, and the feature vector improves the difference of remote sensing features, and it is more conducive to the classification of remote sensing features, and thus it improves the classification accuracy of remote sensing images. It is suitable for remote sensing information extraction of complex surface in southern China. This method can be extended to complex surface area in the future.
基金This project is supported by General Electric Corporate ResearchDevelopment and National Advanced Technology Project of China (No.863-511-942-018).
文摘A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region from the rest of the input point cloud with the processes of sampling point data, estimation of local surface curvature properties and comparison of maximum curvature values. The recovery of parametric representation generates a set of profile curves by marching throughout the blend and fitting cylinders. Compared with the existing approaches of blend surface feature extraction, the proposed method reduces the requirement of user interaction and is capable of extracting blend surface with either constant radius or variable radius. Application examples are presented to verify the proposed method.
文摘This is second paper summarizing the study on the hydrous titanium oxide absorbent for extracting uranium fromseawater. The investigation is performed by means of X- ray photoelectronic energy spectroscopy for chemical analysis ( ESC A ) , determination of surface hydroxy radical, Fourier-transfer infrared spectrophotometry (FT-IR ) , electron paramagnetic resonance (EPR), inductively coupled Plasma torch (ICP), etc. The emphasis is laid upon the exploration of HTO surface and a discussion about the adsorption micromechanism.
基金supported by National Basic Research Program of China (973 Program) (No.2011CB707702)National Natural Science Foundation of China (No.81090272, No.81000632, and No.30900334)+1 种基金Shaanxi Provincial Natural Science Foundation Research Project (No.2009JQ8018)Fundamental Research Funds for the Central Universities
文摘In this contribution, we present an all-optical quantitative framework for bioluminescence tomography with non-contact measurement. The framework is comprised of four indispensable steps： extraction of the geometrical structures of the subject, light flux reconstruction on arbitrary surface, calibration and quantification of the surface light flux and internal bioluminescence reconstruction. In particular, the geometrical structures are retrieved using a completely optical method and captured under identical viewing conditions with the bioluminescent images. As a result, the proposed framework avoids the utilization of computed tomography or magnetic resonance imaging to provide the geometrical structures. On the basis of experimental measurements, we evaluate the performance of the proposed all-optical quantitative framework using a mouse shaped phantom. Preliminary result reveals the potential and feasibility of the proposed framework for bioluminescence tomography.
文摘This paper focuses on entirety ioterpretation, representation and reconstruction of three-dimensional volume data sets based on the physical model of the data. The data model is represented by thIee-dimensional geometric model.The surfaces inside the datafield are extracted and matched to the model stirfaces in order to reconstruct the new datafield based on the model. A conclusion is drawn that physical modeling provides a good basis and approach to interpret and represellt the data sets. This paPer also presents a subdivision algorithm to fast traJce B-spline curve and the colltrary algorithm is adopted to extract the geometry feature of the curve.
