Structural damage is significantly influenced by the various parameters of a close-in explosion.To establish a close-in blast loading model for cylindrical charges according to these parameters,a series of field exper...Structural damage is significantly influenced by the various parameters of a close-in explosion.To establish a close-in blast loading model for cylindrical charges according to these parameters,a series of field experiments and a systematic numerical analysis were conducted.A high-fidelity finite element model developed using AUTODYN was first validated using blast data collected from field tests conducted in this and previous studies.A quantitative analysis was then performed to determine the influence of the charge shape,aspect ratio(length to diameter),orientation,and detonation configuration on the characteristics and distributions of the blast loading(incident peak overpressure and impulse)according to scaled distance.The results revealed that the secondary peak overpressure generated by a cylindrical charge was mainly distributed along the axial direction and was smaller than the overpressure generated by an equivalent spherical charge.The effects of charge shape on the blast loading at 45°and 67.5°in the axial plane could be neglected at scaled distances greater than 2 m/kg^(1/3);the effect of aspect ratios greater than 2 on the peak overpressure in the 90°(radial)direction could be neglected at all scaled distances;and double-end detonation increased the radial blast loading by up to 60%compared to singleend detonation.Finally,an empirical cylindrical charge blast loading model was developed considering the influences of charge aspect ratio,orientation,and detonation configuration.The results obtained in this study can serve as a reference for the design of blast tests using cylindrical charges and aid engineers in the design of blast-resistant structures.展开更多
Smartphones are usually packed with a large number of features.An increasing number of researchers are paying attention to the technological capabilities of smartphones,which is a new topic and research interest.This ...Smartphones are usually packed with a large number of features.An increasing number of researchers are paying attention to the technological capabilities of smartphones,which is a new topic and research interest.This paper proposes a method using smartphones and digital photogrammetry to measure the discontinuity orientation of a rock mass.Smartphone photos satisfying a certain overlap rate provide an efficient method for generating point cloud models of rock outcrops based on image matching.Using the target and the generated point cloud model allows for determining actual geographic coordinates and the measurement of discontinuity orientations.The method proposed has been applied to two different study areas.The discontinuity orientations measured by the proposed method are compared with those measured by the manual method in two cases.The results show a good agreement,verifying the reliability and accuracy of the proposed method.The main contribution of this paper is to use knowledge of coordinate rotation to determine the actual geographic location of the model through a square target.The equipment used in this study is simple,and photogrammetric field surveys are easy to carry out.展开更多
Aspect oriented software development is an emerging paradigm of software development. The notion of this technique is separation of concerns which means to implement each concern in a single object in object oriented ...Aspect oriented software development is an emerging paradigm of software development. The notion of this technique is separation of concerns which means to implement each concern in a single object in object oriented programming but still there are concerns which are distributed on different objects and are called crosscutting concerns while another form is Core concerns are the core functionality provided by the system but crosscutting concerns are the concerns like logging, performance etc. Modeling of aspect oriented software is different from the normal modeling of object-oriented or procedural language software, because aspects don’t have the independent identity or existence and they are tightly coupled to their woven context so it is difficult to model them. The one aim of our research paper is to explore the domain of Modeling of the aspect-oriented software. The goal of this research paper is to give a UML Behavioral modeling techniques in the domain of aspect oriented software development. This technique of generating UML Behavioral Model for aspects will give better understating of separations concerns.展开更多
A novel method for fingerprint singular points extraction including location and orientation is proposed based on some properties of the orientation field models. Singular points are located by clustering the results ...A novel method for fingerprint singular points extraction including location and orientation is proposed based on some properties of the orientation field models. Singular points are located by clustering the results of corner detection. Then, through examining the sub-block orientation fields at a number of selected positions on concentric circles centered about the located singular point, an iterative method based on the orientation differences is proposed to compute the orientation of the core point. Experimental results on NIST4 and FVC2002 four databases demonstrate the proposed method can consistently locate singular points with the high accuracy. The location and orientation of the detected singular points can be used for alignment （translation and rotation） parameters in fingerprint matching.展开更多
基金supported by the National Natural Science Foundation of China[No.51978166]。
文摘Structural damage is significantly influenced by the various parameters of a close-in explosion.To establish a close-in blast loading model for cylindrical charges according to these parameters,a series of field experiments and a systematic numerical analysis were conducted.A high-fidelity finite element model developed using AUTODYN was first validated using blast data collected from field tests conducted in this and previous studies.A quantitative analysis was then performed to determine the influence of the charge shape,aspect ratio(length to diameter),orientation,and detonation configuration on the characteristics and distributions of the blast loading(incident peak overpressure and impulse)according to scaled distance.The results revealed that the secondary peak overpressure generated by a cylindrical charge was mainly distributed along the axial direction and was smaller than the overpressure generated by an equivalent spherical charge.The effects of charge shape on the blast loading at 45°and 67.5°in the axial plane could be neglected at scaled distances greater than 2 m/kg^(1/3);the effect of aspect ratios greater than 2 on the peak overpressure in the 90°(radial)direction could be neglected at all scaled distances;and double-end detonation increased the radial blast loading by up to 60%compared to singleend detonation.Finally,an empirical cylindrical charge blast loading model was developed considering the influences of charge aspect ratio,orientation,and detonation configuration.The results obtained in this study can serve as a reference for the design of blast tests using cylindrical charges and aid engineers in the design of blast-resistant structures.
基金supported by the National Natural Science Foundation of China(Grant No.51769014),which is gratefully acknowledged.
文摘Smartphones are usually packed with a large number of features.An increasing number of researchers are paying attention to the technological capabilities of smartphones,which is a new topic and research interest.This paper proposes a method using smartphones and digital photogrammetry to measure the discontinuity orientation of a rock mass.Smartphone photos satisfying a certain overlap rate provide an efficient method for generating point cloud models of rock outcrops based on image matching.Using the target and the generated point cloud model allows for determining actual geographic coordinates and the measurement of discontinuity orientations.The method proposed has been applied to two different study areas.The discontinuity orientations measured by the proposed method are compared with those measured by the manual method in two cases.The results show a good agreement,verifying the reliability and accuracy of the proposed method.The main contribution of this paper is to use knowledge of coordinate rotation to determine the actual geographic location of the model through a square target.The equipment used in this study is simple,and photogrammetric field surveys are easy to carry out.
文摘Aspect oriented software development is an emerging paradigm of software development. The notion of this technique is separation of concerns which means to implement each concern in a single object in object oriented programming but still there are concerns which are distributed on different objects and are called crosscutting concerns while another form is Core concerns are the core functionality provided by the system but crosscutting concerns are the concerns like logging, performance etc. Modeling of aspect oriented software is different from the normal modeling of object-oriented or procedural language software, because aspects don’t have the independent identity or existence and they are tightly coupled to their woven context so it is difficult to model them. The one aim of our research paper is to explore the domain of Modeling of the aspect-oriented software. The goal of this research paper is to give a UML Behavioral modeling techniques in the domain of aspect oriented software development. This technique of generating UML Behavioral Model for aspects will give better understating of separations concerns.
基金supported by the Key Project of The Ministry of Education of China (108012)the National Natural Science Foundation of China (90920001, 60772114)
文摘A novel method for fingerprint singular points extraction including location and orientation is proposed based on some properties of the orientation field models. Singular points are located by clustering the results of corner detection. Then, through examining the sub-block orientation fields at a number of selected positions on concentric circles centered about the located singular point, an iterative method based on the orientation differences is proposed to compute the orientation of the core point. Experimental results on NIST4 and FVC2002 four databases demonstrate the proposed method can consistently locate singular points with the high accuracy. The location and orientation of the detected singular points can be used for alignment （translation and rotation） parameters in fingerprint matching.
