According to the observation in experiment of stability of the oil film, the assumption of velocity distribution for both the water flow and the oil film is introduced. On the basis of the assumption, Orr-Sommerfeld s...According to the observation in experiment of stability of the oil film, the assumption of velocity distribution for both the water flow and the oil film is introduced. On the basis of the assumption, Orr-Sommerfeld stability equation is applied to develop the method of determining the critical velocity of the oil film, and the criterion for stability of the oil film is obtained. Meanwhile, a formula describing the relation between the thickness of the oil film and the velocity of the water flow is also given and examined by the laboratory experiment.展开更多
Images and videos play an increasingly vital role in daily life and are widely utilized as key evidentiary sources in judicial investigations and forensic analysis.Simultaneously,advancements in image and video proces...Images and videos play an increasingly vital role in daily life and are widely utilized as key evidentiary sources in judicial investigations and forensic analysis.Simultaneously,advancements in image and video processing technologies have facilitated the widespread availability of powerful editing tools,such as Deepfakes,enabling anyone to easily create manipulated or fake visual content,which poses an enormous threat to social security and public trust.To verify the authenticity and integrity of images and videos,numerous approaches have been proposed,which are primarily based on content analysis and their effectiveness is susceptible to interference from various image or video post-processing operations.Recent research has highlighted the potential of file containers analysis as a promising forensic approach that offers efficient and interpretable results.However,there is still a lack of review articles on this kind of approach.In order to fill this gap,we present a comprehensive review of file containers-based image and video forensics in this paper.Specifically,we categorize the existing methods into two distinct stages,qualitative analysis and quantitative analysis.In addition,an overall framework is proposed to organize the exiting approaches.Then,the advantages and disadvantages of the schemes used across different forensic tasks are provided.Finally,we outline the trends in this research area,aiming to provide valuable insights and technical guidance for future research.展开更多
In order to improve the survival rate of planting seedlings of Phoebe zhen-nan, the grading standard for one-year-old container seedlings of Phoebe zhennan was developed by using cluster analysis. The results showed t...In order to improve the survival rate of planting seedlings of Phoebe zhen-nan, the grading standard for one-year-old container seedlings of Phoebe zhennan was developed by using cluster analysis. The results showed that the quality of Phoebe zhennan container seedlings could be estimated from seedling height and ground diameter. The Phoebe zhennan container seedlings were divided into 3 grades： Grade 1 （seedling height ≥ 38 cm; ground diameter ≥ 0.65 cm）, Grade 2 （31.7 cm ≤ seedling height 〈 38 cm; 0.56 cm ≤ ground diameter 〈 0.65 cm） and Grade 3 （seedling height 〈 31.7 cm; ground diameter 〈 0.56 cm）.展开更多
This paper summarizes suitable material models for creep and damage of concrete which are coupled with heat and moisture transfer.The fully coupled approach or the staggered coupling is assumed.Governing equations are...This paper summarizes suitable material models for creep and damage of concrete which are coupled with heat and moisture transfer.The fully coupled approach or the staggered coupling is assumed.Governing equations are spatially discretized by the finite element method and the temporal discretization is done by the generalized trapezoidal method.Systems of non-linear algebraic equations are solved by the Newton method.Development of an efficient and extensible computer code based on the C++programming language is described.Finally,successful analyses of two real engineering problems are described.展开更多
文摘According to the observation in experiment of stability of the oil film, the assumption of velocity distribution for both the water flow and the oil film is introduced. On the basis of the assumption, Orr-Sommerfeld stability equation is applied to develop the method of determining the critical velocity of the oil film, and the criterion for stability of the oil film is obtained. Meanwhile, a formula describing the relation between the thickness of the oil film and the velocity of the water flow is also given and examined by the laboratory experiment.
基金supported in part by Natural Science Foundation of Hubei Province of China under Grant 2023AFB016the 2022 Opening Fund for Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering under Grant 2022SDSJ02the Construction Fund for Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering under Grant 2019ZYYD007.
文摘Images and videos play an increasingly vital role in daily life and are widely utilized as key evidentiary sources in judicial investigations and forensic analysis.Simultaneously,advancements in image and video processing technologies have facilitated the widespread availability of powerful editing tools,such as Deepfakes,enabling anyone to easily create manipulated or fake visual content,which poses an enormous threat to social security and public trust.To verify the authenticity and integrity of images and videos,numerous approaches have been proposed,which are primarily based on content analysis and their effectiveness is susceptible to interference from various image or video post-processing operations.Recent research has highlighted the potential of file containers analysis as a promising forensic approach that offers efficient and interpretable results.However,there is still a lack of review articles on this kind of approach.In order to fill this gap,we present a comprehensive review of file containers-based image and video forensics in this paper.Specifically,we categorize the existing methods into two distinct stages,qualitative analysis and quantitative analysis.In addition,an overall framework is proposed to organize the exiting approaches.Then,the advantages and disadvantages of the schemes used across different forensic tasks are provided.Finally,we outline the trends in this research area,aiming to provide valuable insights and technical guidance for future research.
基金Supported by Forestry Science and Technology Program of Hunan Province(2010-06)~~
文摘In order to improve the survival rate of planting seedlings of Phoebe zhen-nan, the grading standard for one-year-old container seedlings of Phoebe zhennan was developed by using cluster analysis. The results showed that the quality of Phoebe zhennan container seedlings could be estimated from seedling height and ground diameter. The Phoebe zhennan container seedlings were divided into 3 grades： Grade 1 （seedling height ≥ 38 cm; ground diameter ≥ 0.65 cm）, Grade 2 （31.7 cm ≤ seedling height 〈 38 cm; 0.56 cm ≤ ground diameter 〈 0.65 cm） and Grade 3 （seedling height 〈 31.7 cm; ground diameter 〈 0.56 cm）.
基金Financial support for this work was provided by the Czech Science Foundation,projects n.103/08/1119 and 105/10/1682support was provided by the Ministry of Education,Youth and Sports of the Czech Republic,project No.1M0579.
文摘This paper summarizes suitable material models for creep and damage of concrete which are coupled with heat and moisture transfer.The fully coupled approach or the staggered coupling is assumed.Governing equations are spatially discretized by the finite element method and the temporal discretization is done by the generalized trapezoidal method.Systems of non-linear algebraic equations are solved by the Newton method.Development of an efficient and extensible computer code based on the C++programming language is described.Finally,successful analyses of two real engineering problems are described.
