For wireless sensor networks, a simple and accurate coordinate-free k-coverage hole detection scheme is proposed. First, an algorithm is presented to detect boundary cycles of 1-coverage holes. The algorithm consists ...For wireless sensor networks, a simple and accurate coordinate-free k-coverage hole detection scheme is proposed. First, an algorithm is presented to detect boundary cycles of 1-coverage holes. The algorithm consists of two components, named boundary edge detection and boundary cycle detection. Then, the 1-coverage hole detection algorithm is extended to k-coverage hole scenarios. A coverage degree reduction scheme is proposed to find an independent covering set of nodes in the covered region of the target field and to reduce the coverage degree by one through sleeping those nodes. Repeat the 1-coverage hole detection algorithm and the higher order of coverage holes can be found. By iterating the above steps for k-1 times, the boundary edges and boundary cycles of all k-coverage holes can be discovered. Finally, the proposed algorithm is compared with a location-based coverage hole detection algorithm. Simulation results indicate that the proposed algorithm can accurately detect over 99% coverage holes.展开更多
Pipeline plays a vital role in transporting fluids like oils, water, and petrochemical substances for longer distances. Based on the materials they carry</span><span style="white-space:normal;font-size:1...Pipeline plays a vital role in transporting fluids like oils, water, and petrochemical substances for longer distances. Based on the materials they carry</span><span style="white-space:normal;font-size:10pt;font-family:"">,</span><span style="white-space:normal;font-size:10pt;font-family:""> prolonged usage may cause the initiation of defects in the pipeline. These defects occur due to the formed salt deposits, chemical reaction happens between the inner surface and the transferring substance, prevailing environmental conditions, etc. These defects, if not identified earlier may lead to significant losses to the industry. In this work, an in-line inspection system utilizes the nondestructive way for analyzing the internal defects in the petrochemical pipeline. This system consists of a pipeline inspection robot having two major units namely the visual inspection unit and the power carrier unit. The visual inspection unit makes use of a ring-type laser diode and the camera. The laser diode serves as a light source for capturing good quality images of inspection. This unit is controlled by the Arduino in the power carrier unit which provides the necessary movement throughout the pipe. The inspected images captured by the camera are further processed with the aid of NI vision assistant software. After applying the processing function parameters provided by this software, the defect location can be clearly visualized with high precision. Three sets of defects are introduced in a Polylactide (PLA) pipe based on its position and angle along the circumference of the pipe. Further, this robot system serves as a real-time interactive image synchronization system for acquiring the inspected images. By comparing the actual and calculated defect size, the error percentage obtained was less than 5%.展开更多
In some scattered point cloud triangular mesh restoration algorithm, small triangular mesh holes problem will often affect the quality of the model. For small holes at the details, this paper propose a method for iden...In some scattered point cloud triangular mesh restoration algorithm, small triangular mesh holes problem will often affect the quality of the model. For small holes at the details, this paper propose a method for identifying and extracting hollow edge,and use a triangle growth way based on boundary edge angle to fill the empty void. First, according the relationship of the point, side and face of the triangle mesh model to identify the hole, then extracting the holes boundary edge and classifying it. Finally, using a triangle growth method based on holes boundary edge angle to fill each small holes separated from the boundary. Compared with other algorithm of filling holes, this method is high efficiency for small holes of smooth surface,and itimprovesthe quality of the triangular mesh model.展开更多
The identification of objects in binary images is a fundamental task in image analysis and pattern recognition tasks. The Euler number of a binary image is an important topological measure which is used as a feature i...The identification of objects in binary images is a fundamental task in image analysis and pattern recognition tasks. The Euler number of a binary image is an important topological measure which is used as a feature in image analysis. In this paper, a very fast algorithm for the detection and localization of the objects and the computation of the Euler number of a binary image is proposed. The proposed algorithm operates in one scan of the image and is based on the Image Block Representation (IBR) scheme. The proposed algorithm is more efficient than conventional pixel based algorithms in terms of execution speed and representation of the extracted information.展开更多
基金The National Natural Science Foundation of China(No.61601122,61471164,61741102)
文摘For wireless sensor networks, a simple and accurate coordinate-free k-coverage hole detection scheme is proposed. First, an algorithm is presented to detect boundary cycles of 1-coverage holes. The algorithm consists of two components, named boundary edge detection and boundary cycle detection. Then, the 1-coverage hole detection algorithm is extended to k-coverage hole scenarios. A coverage degree reduction scheme is proposed to find an independent covering set of nodes in the covered region of the target field and to reduce the coverage degree by one through sleeping those nodes. Repeat the 1-coverage hole detection algorithm and the higher order of coverage holes can be found. By iterating the above steps for k-1 times, the boundary edges and boundary cycles of all k-coverage holes can be discovered. Finally, the proposed algorithm is compared with a location-based coverage hole detection algorithm. Simulation results indicate that the proposed algorithm can accurately detect over 99% coverage holes.
文摘Pipeline plays a vital role in transporting fluids like oils, water, and petrochemical substances for longer distances. Based on the materials they carry</span><span style="white-space:normal;font-size:10pt;font-family:"">,</span><span style="white-space:normal;font-size:10pt;font-family:""> prolonged usage may cause the initiation of defects in the pipeline. These defects occur due to the formed salt deposits, chemical reaction happens between the inner surface and the transferring substance, prevailing environmental conditions, etc. These defects, if not identified earlier may lead to significant losses to the industry. In this work, an in-line inspection system utilizes the nondestructive way for analyzing the internal defects in the petrochemical pipeline. This system consists of a pipeline inspection robot having two major units namely the visual inspection unit and the power carrier unit. The visual inspection unit makes use of a ring-type laser diode and the camera. The laser diode serves as a light source for capturing good quality images of inspection. This unit is controlled by the Arduino in the power carrier unit which provides the necessary movement throughout the pipe. The inspected images captured by the camera are further processed with the aid of NI vision assistant software. After applying the processing function parameters provided by this software, the defect location can be clearly visualized with high precision. Three sets of defects are introduced in a Polylactide (PLA) pipe based on its position and angle along the circumference of the pipe. Further, this robot system serves as a real-time interactive image synchronization system for acquiring the inspected images. By comparing the actual and calculated defect size, the error percentage obtained was less than 5%.
文摘In some scattered point cloud triangular mesh restoration algorithm, small triangular mesh holes problem will often affect the quality of the model. For small holes at the details, this paper propose a method for identifying and extracting hollow edge,and use a triangle growth way based on boundary edge angle to fill the empty void. First, according the relationship of the point, side and face of the triangle mesh model to identify the hole, then extracting the holes boundary edge and classifying it. Finally, using a triangle growth method based on holes boundary edge angle to fill each small holes separated from the boundary. Compared with other algorithm of filling holes, this method is high efficiency for small holes of smooth surface,and itimprovesthe quality of the triangular mesh model.
文摘The identification of objects in binary images is a fundamental task in image analysis and pattern recognition tasks. The Euler number of a binary image is an important topological measure which is used as a feature in image analysis. In this paper, a very fast algorithm for the detection and localization of the objects and the computation of the Euler number of a binary image is proposed. The proposed algorithm operates in one scan of the image and is based on the Image Block Representation (IBR) scheme. The proposed algorithm is more efficient than conventional pixel based algorithms in terms of execution speed and representation of the extracted information.
