Problem Of Non-uniform Distribution Research Articles

Adaptive Superpixel-Based Disparity Estimation Algorithm Using Plane Information and Disparity Refining Mechanism in Stereo Matching

The motivation of this paper is to address the limitations of the conventional keypoint-based disparity estimation methods. Conventionally, disparity estimation is usually based on the local information of keypoints. However, keypoints may distribute sparsely in the smooth region, and keypoints with the same descriptors may appear in a symmetric pattern. Therefore, conventional keypoint-based disparity estimation methods may have limited performance in smooth and symmetric regions. The proposed algorithm is superpixel-based. Instead of performing keypoint matching, both keypoint and semiglobal information are applied to determine the disparity in the proposed algorithm. Since the local information of keypoints and the semi-global information of the superpixel are both applied, the accuracy of disparity estimation can be improved, especially for smooth and symmetric regions. Moreover, to address the non-uniform distribution problem of keypoints, a disparity refining mechanism based on the similarity and the distance of neighboring superpixels is applied to correct the disparity of the superpixel with no or few keypoints. The experiments show that the disparity map generated by the proposed algorithm has a lower matching error rate than that generated by other methods.

MVTLR-HCFS: Density Peak Algorithm Based on Multi-View and Tensor Low Rank Expression

With the rapid development of hardware and software technology, modern industry has produced a large amount of high-dimensional unlabeled data, such as pictures and videos. As clusters of these data sets may exist in some subspaces, traditional algorithms are no longer applicable. The related algorithms based on sparse subspace can find clusters in the subspace, which solves the problem of high data dimension. However, their clustering process based on only one single feature, which results in their performance being particularly sensitive to this single view. Affected by the integrated algorithm, a large number of multi-view methods began to emerge. These methods improve the clustering performance by integrating the subspace expressions of multiple views, but the problem is that the complementary information of multiple views cannot be fully considered. In addition, the problem of non-uniform distribution in clusters also exists in high-dimensional data sets. In this paper, based on the multi-view subspace clustering method, a clustering algorithm based on tensor low rank expression is proposed to solve the clustering problem of high-dimensional datasets. On the one hand, this paper solves the problem of noise and data corruption by combining the method of $\ell _{2,1} $ norms, which transform the optimization problem of solving multi-view subspace expression into a low-rank expression problem of tensor to fully consider the complementarities between views. On the other hand, the proposed scheme solves the problem of non- uniform distribution in clusters in high-dimensional data by combining with the density peak algorithm based on hierarchical strategy. Experiment results show the effectiveness of the algorithm.

Simulation and Experiment of New Ultrasonic Vibration Network

A reasonable ultrasonic vibration network can improve the casting quality of aluminum alloy. Ultrasonic vibration network based on a honeycomb structure has been designed, referred to as a new vibration network. The new vibration network can solve the problems of nonuniform distribution of power ultrasonic wave, small working area and low volume of ultrasonic vibration network, low efficiency of the frequency spectrum and power spectrum, and poor quality of aluminum alloy casting. The number of vibration nodes can be determined based on the number of layers of the vibration source nodes. The edge length of regular hexagonal honeycomb cells can be determined based on the size of the casting ingot. The output power and resonant frequency of the ultrasonic vibration network can be adjusted in real time according to the status of aluminum alloy melt. A seven-node new ultrasonic network and a four-node ultrasonic network with a traditional structure were selected and used in the experiment and simulation of a 500 mm diameter 2219 aluminum alloy ingot. In comparison with the traditional four-node ultrasonic network, the effective volume and area, frequency spectrum efficiency, and comprehensive coverage probability of the seven-node new ultrasonic vibration network increased by 34.06%, 23.12%, 17.25%, and 0.308, respectively. The difference between the desired value and average efficiency of the power spectrum was 0.292 W/cm2, and the average grain size of aluminum alloy decreased by 34.98 microns. These results indicate that the efficiency of ultrasonic-vibration-assisted casting system and the quality of aluminum alloy casting can be improved using the new ultrasonic vibration network.

Turbulent heat transfer analysis in supercritical hydrogen fuel flow considering thermal stratification

Due to the single-side heating on the rectangular channel, the coolant faces a serious thermal stratification problem, and thus the heat transfer performance is reduced. To effectively improve flow and heat transfer characteristics, and weaken nonuniform distribution problem, a new cooling structure with combining fin and spherical convexity is built in this paper. The study results indicate that the new structure effectively reduced the maximum heat wall temperature, and weakened the fluid nonuniform distribution problem. Comparing with smooth channel and spherical convexity structure, the maximum temperature is decreased by 18.4% and 10.3%, and temperature nonuniform index is decreased by 25.1% and 20.8%. In addition, as the higher fluid temperature means the higher specific heat capacity, the new structure made full use of the heat sink of hydrogen, making the more heat can be quickly taken away from the heat wall. The thermal stratification phenomenon can be obviously weakened.

Study of Particle Distribution in Al-SiC Particulate Composite by Random Motion of Mould

Synthesis of Al metal matrix composites (MMCs) with ceramic particulate reinforcements through casting route is associated with the problem of non-uniform distribution of particulate. The problem of non-uniform distribution is more for the case of larger particulate volume fraction. In the present study a novel method has been tried to overcome this. It involves random movement of mold containing liquid aluminium and ceramic particulates ieSiC. In the present studythe spherical mold containing molten aluminium and SiC particulates of size 50-100µm is allowed to rotate in a cylindrical drum to impart a random rotation as well translation Before the design of experiment the process simulation has already been done. Accordingly the process has been fabricated. At present the process is a crude one. Preliminary experiments show that the distributions of particles obtained by this technique are better as compared to that of stir cast composites with similar volume fraction of reinforcement. However, the result obtained by the novel technique varied as proper control over the random motion of the mold was not possible. Although uniform microstructure could be obtained in most of the experiment in some cases and certain zones the microstructure showed a non uniform distribution of particles. The temperature of mold before it is subjected to random movement is strongly influenced the particle distribution.

Sampling of Nicotiana tabacum leaf lamina to surmount the problem of nonuniform distribution of total alkaloids

Nonuniform distribution of total alkaloids in leaf lamina of Nicotiana tabacum requires precise positioning of the fixed diameter cutter in obtaining leaf disks which provide a reliable estimate of total alkaloids content of the leaf. This is time-consuming. Other methods such as the whole leaf technique yield excessive amounts of tissue to process. Our procedure uses a band technique that overcomes the problems associated with the unequal distribution of total alkaloids in the lamina and increases sampling rate threefold. This procedure is superior to others for sampling the different sizes of leaves on the plant at anyone time until maturity.