21 research outputs found

    Defect detection of wire rope for oil well based on adaptive angle

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    This paper uses a digital image processing method which is based on texture feature of steel cable to detect the fracture of steel wire. At first, it uses a modified homomorphic filtering method to eliminate environment heterogeneous shining. Next, it obtains the body image of the steel line by using the method of edge detecting and section counting filtering to detect the bunch part of steel wire. By using an improved Radon transformation method to indicate if those steel wire are in good condition or not. Finally, by using BP neural network model it aims to judge the final result. Test result shows that this method is easy to use and fulfill real time request

    Defect detection of wire rope for oil well based on adaptive angle

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    This paper uses a digital image processing method which is based on texture feature of steel cable to detect the fracture of steel wire. At first, it uses a modified homomorphic filtering method to eliminate environment heterogeneous shining. Next, it obtains the body image of the steel line by using the method of edge detecting and section counting filtering to detect the bunch part of steel wire. By using an improved Radon transformation method to indicate if those steel wire are in good condition or not. Finally, by using BP neural network model it aims to judge the final result. Test result shows that this method is easy to use and fulfill real time reques

    Comprehensive Management and Operational Development of Suomu Ski Resort

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    This article-based thesis is a specific research about the management and operation of Suomu Ski Resort. The thesis consists of five separate articles regarding the ski resort’s marketing, destination management, human resource management, risk and crisis management and sustainability. General introduction of Suomu, background of study and methods used in the research process have been illuminated in the common theoretical framework. The authors demonstrated the results of their individual study and devised development plan for the ski resort in conclusions of the research

    A Block Object Detection Method Based on Feature Fusion Networks for Autonomous Vehicles

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    Nowadays, automatic multi-objective detection remains a challenging problem for autonomous vehicle technologies. In the past decades, deep learning has been demonstrated successful for multi-objective detection, such as the Single Shot Multibox Detector (SSD) model. The current trend is to train the deep Convolutional Neural Networks (CNNs) with online autonomous vehicle datasets. However, network performance usually degrades when small objects are detected. Moreover, the existing autonomous vehicle datasets could not meet the need for domestic traffic environment. To improve the detection performance of small objects and ensure the validity of the dataset, we propose a new method. Specifically, the original images are divided into blocks as input to a VGG-16 network which add the feature map fusion after CNNs. Moreover, the image pyramid is built to project all the blocks detection results at the original objects size as much as possible. In addition to improving the detection method, a new autonomous driving vehicle dataset is created, in which the object categories and labelling criteria are defined, and a data augmentation method is proposed. The experimental results on the new datasets show that the performance of the proposed method is greatly improved, especially for small objects detection in large image. Moreover, the proposed method is adaptive to complex climatic conditions and contributes a lot for autonomous vehicle perception and planning

    The Suppression Characteristics of NH4H2PO4/Red Mud Composite Powders on Methane Explosion

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    The composite powders composed of red mud (RM) and NH4H2PO4 (NH4H2PO4/RM) were successfully prepared by the anti-solvent method. The composition and structure of the NH4H2PO4/RM composite powders were characterized by the techniques of X-ray diffraction (XRD), SEM, N2 adsorption-desorption and Thermogravimetry-Differential scanning calorimetry (TG-DSC). The analysis results indicate that the as-prepared samples are composed with uniform nanoparticles and possess the porous structure. The methane explosion suppression characteristics of the NH4H2PO4/RM composite powders were tested by a 20 L spherical explosion system and a 5 L pipe test system. The results show that the NH4H2PO4/RM composite powders possess considerable suppression properties on methane explosion. When the loading content of NH4H2PO4 reached 30%, the maximum pressure and the maximum pressure rise rate of methane explosion were decreased by 35.1% and 95.8%, respectively. When comparing with no powder addition, the time to reach the pressure peak was extended from 0.07 s to 0.50 s. The NH4H2PO4/RM composite powders presented a synergistic suppression effect between NH4H2PO4 and RM, which made it exhibit considerable suppression property than that of pure NH4H2PO4 or red mud powders

    Video-Based Vehicle Counting for Expressway: A Novel Approach Based on Vehicle Detection and Correlation-Matched Tracking Using Image Data from PTZ Cameras

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    Vehicle counting plays a significant role in vehicle behavior analysis and traffic incident detection for established video surveillance systems on expressway. Since the existing sensor method and the traditional image processing method have the problems of difficulty in installation, high cost, and low precision, a novel vehicle counting method is proposed, which realizes efficient counting based on multivehicle detection and multivehicle tracking. For multivehicle detection tasks, a construction of the new expressway dataset consists of a large number of sample images with a high resolution (1920 × 1080) captured from real-world expressway scenes (including the diversity climatic conditions and visual angles) by Pan-Tilt-Zoom (PTZ) cameras, in which vehicle categories and annotation rules are defined. Moreover, a correlation-matched algorithm for multivehicle tracking is proposed, which solves the problem of occlusion and vehicle scale change in the tracking process. Due to the discontinuity and unsmooth of the trajectories that occurred during the tracking process, we designed a trajectory optimization algorithm based on least square method. Finally, a new vehicle counting method is designed based on the tracking results, in which the driving direction information of the vehicle is added in the counting process. The experimental results show that the proposed counting method in this research can achieve more than 93% accuracy and an average speed of 25 frames per second in expressway video sequence

    The Inhibition Effect of Gas–Solid Two-Phase Inhibitors on Methane Explosion

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    In order to study the inhibition effect of gas⁻solid two-phase inhibitors on a methane explosion, the influence of these parameters was investigated and compared with that of single-phase inhibitors. The results show that the inhibition effect of gas⁻solid two-phase inhibitors on a methane explosion is better than the added effect of two single-phase inhibitors, indicating that a synergistic effect can be obtained by gas⁻solid two-phase inhibitors. The two-phase inhibitors which are composed of NaHCO3 (BC) powders and inert gas have a better suppressing property than those composed of NH4H2PO4 (ABC) powders and inert gas. The two-phase inhibitors composed of CO2 and powders have a better suppressing property than those composed of N2 and powders. The 9.5% premixed methane⁻air mixture can be completely inhibited by 0.10 g/L BC powders mixed with 8% CO2. The suppression mechanisms of the gas⁻solid two-phase inhibitors on the methane explosion were discussed

    Borane-Catalyzed Transfer Hydrogenations of Pyridines with Ammonia Borane

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    With the use of ammonia borane as a hydrogen source, a borane catalyzed metal-free transfer hydrogenation of pyridines was successfully realized for the first time to furnish a variety of piperidines in 44–88% yields with moderate to excellent <i>cis</i>-selectivities. The ease in handling without requiring high pressure H<sub>2</sub> makes this transfer hydrogenation practical and useful
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