Mobile User Interface Pattern Clustering Using Improved Semi-Supervised Kernel Fuzzy Clustering Method

Wei Jia,Qingyi Hua,Minjun Zhang,Rui Chen,Xiang Ji,Bo Wang 한국정보처리학회 2019 Journal of information processing systems Vol.15 No.4

Mobile user interface pattern (MUIP) is a kind of structured representation of interaction design knowledge. Several studies have suggested that MUIPs are a proven solution for recurring mobile interface design problems. To facilitate MUIP selection, an effective clustering method is required to discover hidden knowledge of patterndata set. In this paper, we employ the semi-supervised kernel fuzzy c-means clustering (SSKFCM) method tocluster MUIP data. In order to improve the performance of clustering, clustering parameters are optimized byutilizing the global optimization capability of particle swarm optimization (PSO) algorithm. Since the PSOalgorithm is easily trapped in local optima, a novel PSO algorithm is presented in this paper. It combines animproved intuitionistic fuzzy entropy measure and a new population search strategy to enhance the populationsearch capability and accelerate the convergence speed. Experimental results show the effectiveness andsuperiority of the proposed clustering method.

Multi-scale Local Difference Directional Number Pattern for Group-housed Pigs Recognition

( Weijia Huang ),( Weixing Zhu ),( Zhengyan Zhang ),( Yizheng Guo ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.9

In this paper, a multi-scale local difference directional number (MLDDN) pattern is proposed for pig identification. Firstly, the color images of individual pig are converted into grey images by the most significant bits (MSB) quantization, which makes the grey values have better discrimination. Then, Gabor amplitude and phase responses on different scales are obtained by convoluting the grey images with Gabor masks. Next, by calculating the main difference of local edge directions instead of traditionally edge information, the directional numbers of Gabor amplitude and phase responses are encoded. Finally, the block histograms of the encoded images are concatenated on each scale, and the maximum pooling is adopted on different scales to avoid the high feature dimension. Experimental results on two pigsties show that MLDDN impressively outperforms the other widely used local descriptors.

Hardware/Software Partitioning of Combination of Clustering Algorithm and Genetic Algorithm

Weijia Li,Lanying Li,Jianda Sun,Zhiqiang Lv,Fei Guan 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.1

Seismic wave propagation through surface basalts – implications for coal seismic surveys

Weijia Sun,Binzhong Zhou,Peter Hatherly,Li-Yun Fu 한국지구물리.물리탐사학회 2010 지구물리와 물리탐사 Vol.13 No.1

Seismic reflection surveying is one of the most widely used and effective techniques for coal seam structure delineation and risk mitigation for underground longwall mining. However, the ability of the method can be compromised by the presence of volcanic cover. This problem arises within parts of the Bowen and Sydney Basins of Australia and seismic surveying can be unsuccessful. As a consequence, such areas are less attractive for coal mining. Techniques to improve the success of seismic surveying over basalt flows are needed. In this paper, we use elastic wave-equation-based forward modelling techniques to investigate the effects and characteristics of seismic wave propagation under different settings involving changes in basalt properties, its thickness,lateral extent, relative position to the shot position and various forms of inhomogeneity. The modelling results suggests that:1) basalts with high impedance contrasts and multiple flows generate strong multiples and weak reflectors; 2) thin basalts have less effect than thick basalts; 3) partial basalt cover has less effect than full basalt cover; 4) low frequency seismic waves (especially at large offsets) have better penetration through the basalt than high frequency waves; and 5) the deeper the coal seams are below basalts of limited extent, the less influence the basalts will have on the wave propagation. In addition to providing insights into the issues that arise when seismic surveying under basalts, these observations suggest that careful management of seismic noise and the acquisition of long-offset seismic data with low-frequency geophones have the potential to improve the seismic results.

Dynamic/static stability characteristics of sandwich FG porous beams

Weijia Yu,Linyun Zhou 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.2

In the present research, dynamic deflections of a sandwich beam having functionally graded (FG) porous core have been investigated assuming that the sandwich beam is exposed to a pulse load of blast type. The two layers of sandwich beam have been made of a polymeric matrix reinforced by graphene oxide powder (GOP). The micromechanical formulation of the layers has been done via Halpin-Tsai model. The solution method is chosen to be Ritz method which is an efficient method to solve the system of equations of beams modeled based on a higher-order theory. To derive the time history of sandwich beam under pulse load, Laplace method has been used. The porosity content of the core, the GOP content of the layers, thickness of the layer and also duration of the applied load have great influences of the responses of sandwich beam.

Starch graft copolymer and polymer gel applied in Bohai oilfield for water plugging and profile control and their mechanisms

Weijia Cao,Kun Xie,Xiaoyan Wang,Xiangguo Lu,Xin He,Guorui Xu,Xiang Li 한국자원공학회 2020 Geosystem engineering Vol.23 No.4

Water plugging and profile control are becoming increasingly important in water-flooding oilfields. In this study, the experiments were conducted to determine the microscopic mechanisms and effects of water plugging, profile control, and ‘water plugging + profile control’. Initially, the starch graft copolymer and polymer gel used showed only slight changes in viscosity. However, within 12 h, the viscosities exceeded 100,000 mPa·s, which indicated that the two agents had good plugging effects. When the plugging agent was starch graft copolymer, the oil recovery with water plugging was 2% and 0.8% higher than the values for profile control with polymer gel on a heterogeneous core and parallel core, respectively. The recoveries with the ‘water plugging + profile control’ combination for the heterogeneous core and parallel core were 25.9% and 25.5%, respectively, which showed the superior enhanced oil recovery. The mechanism research showed that when the reservoir entered the middle and high water-cut development stages, the residual oil was mainly distributed in the middle- and low-permeability layers near the oil well. Thus, water plugging provided a greater increase in oil recovery. Under the actual demands of the Bohai oilfield, it would be better to adopt a combined water plugging and profile control operation.

Core@shell MOFs derived Co2P/CoP@NPGC as a highly-active bifunctional electrocatalyst for ORR/OER

Weijia Gong,Hongyu Zhang,Liuyang Zhou,Ya Yang,Jiashuo Wang,Heng Liang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

In this study, Co2P/CoP hybrid nanoparticles (NPs) imbedded on the surface of core–shell metal–organicframeworks (MOFs) derived three-dimensional N, P co-doped graphitized carbon (Co2P/CoP@NPGC) areprepared via direct pyrolysis of P-containing MOF precursors. P dopant dosage is tailored to adjust activesites and crystalline phases of Co2P/CoP@NPGC. The active Co2P and CoP NPs and the synergistic effectfrom the Co-Nx/C and Co-P/C active sites and porous NPGC make the dominant contributions to theORR/OER. For ORR, the half-wave potential of Co2P/CoP@NPGC-1 is 0.93 V, which is superior to that ofPt/C (E1/2 = 0.875 V). As for OER, Co2P/CoP@NPGC-1 displays a lower overpotential (ƞ = 340 mV) comparedto RuO2 (ƞ = 380 mV, at 10 mA cm2). The Co2P@CoOOH heterojunction guarantees intrinsic conductivity. Furthermore, doping with N and P can modify the surface electronic structure of catalyst to lower theenergy of oxygen adsorption and dissociation, which are beneficial to enhance the ORR and OER activity. Additionally, its bifunctional activity parameter (DE) for ORR and OER is only 0.64 V, which is lower thanthat of Pt/C and RuO2 (0.76 V). Therefore, this work proposes a new sight into constructing a competitivecore–shell MOFs derived electrocatalyst for ORR/OER.

Fractional Order Sliding Mode Control for Permanent Magnet Synchronous Motor Speed Servo System via an Improved Disturbance Observer

Weijia Zheng,Runquan Huang,Meijin Lin,Fang Guo,YangQuan Chen,Xiaohong Wang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4

A fractional order sliding mode control (FOSMC) method is developed in this paper to deal with the control problem of permanent magnet synchronous motor (PMSM) speed servo system subject to multiple disturbances including model uncertainties, unknown constant disturbances and harmonic disturbances. The lumped exogenous disturbances and uncertainties of the PMSM speed servo are estimated by an improved disturbance observer (DO) and an extended state observer (ESO), respectively. Then, a novel FOSMC law is developed by incorporating the feedforward compensation and a fractional order switching law. The stability of the closed-loop system is established based on Lyapunov stability approach. Under the FOSMC scheme, the tracking performance and robustness of the PMSM servo system are improved simultaneously in the presence of mismatched disturbance torques and measurement noise. The effectiveness and advantages of the proposed method are demonstrated by the PMSM speed regulation experiments and the comparisons with some existing methods.

Bandwidth-efficient Cooperative Diversity with Rotated Constellations and Its Performance Analysis

( Weijia Lei ),( Xiangming Li ),( Xianzhong Xie ) 한국인터넷정보학회 2010 KSII Transactions on Internet and Information Syst Vol.4 No.6

Cooperative diversity is a technique with which a virtual multiple antenna array is established among the single antenna users of the wireless network to realize space diversity. Signal space diversity (SSD) is a bandwidth-efficient diversity technique, which uses constellation rotation and interleaving techniques to achieve diversity gain. A new cooperative diversity scheme with rotated constellations (RCCD) is proposed in this paper. In this scheme, data are modulated by using a rotated constellation, and the source and the relays transmit different components of the modulated symbols. Since any one of the components contains full information of the symbols, the destination can obtain multiple signals conveying the same information from different users. In this way, space diversity is achieved. The RCCD scheme inherits the advantage of SSD - being bandwidth-efficient but without the delay problem of SSD brought by interleaving. The symbol error rate of the RCCD scheme is analyzed and simulated. The analysis and simulation results show that the RCCD scheme can achieve full diversity order of two when the inter-user channel is good enough, and, with the same bandwidth efficiency, has a better performance than amplify-and-forward and detect-and-forward methods.

Seismic wave propagation through surface basalts - implications for coal seismic surveys

Sun, Weijia,Zhou, Binzhong,Hatherly, Peter,Fu, Li-Yun Korean Society of Earth and Exploration Geophysici 2010 지구물리와 물리탐사 Vol.13 No.1

Seismic reflection surveying is one of the most widely used and effective techniques for coal seam structure delineation and risk mitigation for underground longwall mining. However, the ability of the method can be compromised by the presence of volcanic cover. This problem arises within parts of the Bowen and Sydney Basins of Australia and seismic surveying can be unsuccessful. As a consequence, such areas are less attractive for coal mining. Techniques to improve the success of seismic surveying over basalt flows are needed. In this paper, we use elastic wave-equation-based forward modelling techniques to investigate the effects and characteristics of seismic wave propagation under different settings involving changes in basalt properties, its thickness, lateral extent, relative position to the shot position and various forms of inhomogeneity. The modelling results suggests that: 1) basalts with high impedance contrasts and multiple flows generate strong multiples and weak reflectors; 2) thin basalts have less effect than thick basalts; 3) partial basalt cover has less effect than full basalt cover; 4) low frequency seismic waves (especially at large offsets) have better penetration through the basalt than high frequency waves; and 5) the deeper the coal seams are below basalts of limited extent, the less influence the basalts will have on the wave propagation. In addition to providing insights into the issues that arise when seismic surveying under basalts, these observations suggest that careful management of seismic noise and the acquisition of long-offset seismic data with low-frequency geophones have the potential to improve the seismic results.