摘要 :
This paper proposed a novel method, scaleable moving window (SMW), to mine spatial association rules while fully taking the fact that spatial heterogeneity may widely exist. SMW is based on the traditional association rule mining ...
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This paper proposed a novel method, scaleable moving window (SMW), to mine spatial association rules while fully taking the fact that spatial heterogeneity may widely exist. SMW is based on the traditional association rule mining algorithm, Apriori. However, we integrated different moving windows (in terms of window size and shape) with Apriori. During the spatial association mining process, various sizes of windows were used to move over the region of interest. Each window, after moving through the whole region, will produce a set of association rules within the current location of the moving window. The spatial association pattern was represented by the support value and confidence value of spatial association within all the locations of the moving window by Apriori algorithm. Different windows were tested to compare the effectiveness of the windows. Compared with traditional method where the spatial association was assumed to be for the whole region, the proposed method could well reflect the reality by giving the fact that spatial association spatially varies when spatial heterogeneity exists. This proposed method was applied in the provincial capital city, Wuhan, Hubei province, China where the spatial associations between residential buildings and roads showed spatially varied, which reflected the real condition of the city.
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摘要 :
This paper proposed a novel method, scaleable moving window (SMW), to mine spatial association ruleswhile fully taking the fact that spatial heterogeneity may widely exist. SMW is based on the traditional associationrule mining al...
展开
This paper proposed a novel method, scaleable moving window (SMW), to mine spatial association ruleswhile fully taking the fact that spatial heterogeneity may widely exist. SMW is based on the traditional associationrule mining algorithm, Apriori. However, we integrated different moving windows (in terms of window size andshape) with Apriori. During the spatial association mining process, various sizes of windows were used to move overthe region of interest. Each window, after moving through the whole region, will produce a set of association ruleswithin the current location of the moving window. The spatial association pattern was represented by the supportvalue and confidence value of spatial association within all the locations of the moving window by Apriori algorithm.Different windows were tested to compare the effectiveness of the windows. Compared with traditional methodwhere the spatial association was assumed to be for the whole region, the proposed method could well reflect thereality by giving the fact that spatial association spatially varies when spatial heterogeneity exists. This proposedmethod was applied in the provincial capital city, Wuhan, Hubei province, China where the spatial associationsbetween residential buildings and roads showed spatially varied, which reflected the real condition of the city.
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摘要 :
Under the influence of the wind loads, the prestress of guy in the guyed door type transmission tower has a great impact on the mechanical properties of its structure. In order to study this effect, The paper establishes the appro...
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Under the influence of the wind loads, the prestress of guy in the guyed door type transmission tower has a great impact on the mechanical properties of its structure. In order to study this effect, The paper establishes the appropriate nonlinear finite element model of the guy-door- type transmission tower through the use of structural analysis software, analysis the mechanical properties of the tower structure under different initial stress on the condition of the most negative angle of attack, obtain the rule that the changes of initial stress of guy has an influence on the support reaction of guyed transmission tower, the maximum displacement of tower nodes and the bar axial stress, providing the available value for the design and constriction of tower structure, and ensuring transmission tower structure self-reliance .stability and well run.
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摘要 :
Under the influence of the wind loads, the prestress of guy in the guyed door type transmission tower has a great impact on the mechanical properties of its structure. In order to study this effect, The paper establishes the appro...
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Under the influence of the wind loads, the prestress of guy in the guyed door type transmission tower has a great impact on the mechanical properties of its structure. In order to study this effect, The paper establishes the appropriate nonlinear finite element model of the guy-door-type transmission tower through the use of structural analysis software, analysis the mechanical properties of the tower structure under different initial stress on the condition of the most negative angle of attack, obtain the rule that the changes of initial stress of guy has an influence on the support reaction of guyed transmission tower, the maximum displacement of tower nodes and the bar axial stress,providing the available value for the design and constriction of tower structure,and ensuring transmission tower structure self-reliance ,stability and well run.
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This paper presents an approach for improving the stability and adaptability of normal-mode theory, applied to marine environment sound field modeling and calculation. Firstly, based on the custom loss function, both Single Output...
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This paper presents an approach for improving the stability and adaptability of normal-mode theory, applied to marine environment sound field modeling and calculation. Firstly, based on the custom loss function, both Single Output Joint Neural Network (SOJNN) and Multi Output Neural Network (MONN) with physical constraints are constructed to obtain the prediction of wave numbers and eigenfunction. Secondly, we converted the complex wave numbers of normal-mode into a function to find the extreme value, as well as combining the boundary conditions set as the loss function. In this way, the problem space is constrained to the solution space and the dimension of the search space is reduced. Finally, the corresponding sound field is obtained according to the wave numbers and eigenfunction output by neural network. We set the sound velocity at 1500m/s with the density of water is 1g/cm3, place the sound source at 32 meters underwater. The upper boundary is absolutely soft and the lower boundary is absolutely hard. The effectiveness of our method is verified by simulation.
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摘要 :
Aiming at the problem of early weak fault diagnosis for rolling bearings, an early fault diagnosis method based on time-domain marginal spectrum of S transform and successive variational mode decomposition(SVMD) is proposed. First...
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Aiming at the problem of early weak fault diagnosis for rolling bearings, an early fault diagnosis method based on time-domain marginal spectrum of S transform and successive variational mode decomposition(SVMD) is proposed. Firstly, the S transform is used to process the bearing fault signal and the time-domain marginal spectrum is extracted. Then time-domain marginal spectrum S transform is decomposed adaptively by using SVMD and the IMF components which are close to the bearing fault feature frequency are automatically selected for reconstruction. Finally, spectrum analysis of the reconstructed time-domain marginal spectrum of S transform is employed to realize bearing fault diagnosis. Experimental results show that the proposed method can extract weak fault feature components effectively, thereby significantly improving early fault diagnosis accuracy for rolling bearings.
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Misfire of diesel engine was simulated by the bench test. Top center signal and cylinder vibration signal were collected under different states. The vibration signal from each cylinder's combustion period was intercepted according...
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Misfire of diesel engine was simulated by the bench test. Top center signal and cylinder vibration signal were collected under different states. The vibration signal from each cylinder's combustion period was intercepted according to the diesel combustion sequence, effective value was calculated. The short-time effective values were reduced by rough sets, and BP Neural Network model built with the reduced character was used to diagnosis diesel misfire. The result showed this method could locate the misfire cylinder correctly, and it was meaningful for guiding the detection and repair of vehicle.
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摘要 :
Based on the Rayleigh-Plesset-Keller-Kolodner equation, the dynamics of single bubble is calculated regarding water as work medium in the conditions of different ratio of inlet pressure and outlet pressure. The flow field in ventu...
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Based on the Rayleigh-Plesset-Keller-Kolodner equation, the dynamics of single bubble is calculated regarding water as work medium in the conditions of different ratio of inlet pressure and outlet pressure. The flow field in venturi is simulated by fluid dynamics. The results show that the velocity in throat location and maximum cavitation volume fraction increase with ratio of inlet pressure and outlet pressure increasing. The area of cavitation extends. The pressure in throat location reduces and then become stable. The maximum growth rate of single bubble and pressure pulse in bubble increase significantly. The recurrence times of growth and collapsing increases. The influence of single bubble dynamics on the distribution of the whole flow field depends on the turbulence intensity. The more severe the turbulence in venture, the less the effect of single bubble on the whole flow field.
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摘要 :
Based on the Rayleigh-Plesset-Keller-Kolodner equation, the dynamics of single bubble is calculated regarding water as work medium in the conditions of different ratio of inlet pressure and outlet pressure. The flow field in ventu...
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Based on the Rayleigh-Plesset-Keller-Kolodner equation, the dynamics of single bubble is calculated regarding water as work medium in the conditions of different ratio of inlet pressure and outlet pressure. The flow field in venturi is simulated by fluid dynamics. The results show that the velocity in throat location and maximum cavitation volume fraction increase with ratio of inlet pressure and outlet pressure increasing. The area of cavitation extends. The pressure in throat location reduces and then become stable. The maximum growth rate of single bubble and pressure pulse in bubble increase significantly. The recurrence times of growth and collapsing increases. The influence of single bubble dynamics on the distribution of the whole flow field depends on the turbulence intensity. The more severe the turbulence in venture, the less the effect of single bubble on the whole flow field.
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摘要 :
Based on the Rayleigh-Plesset-Keller-Kolodner equation, the dynamics of single bubble is calculated regarding water as work medium in the conditions of different ratio of inlet pressure and outlet pressure. The flow field in ventu...
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Based on the Rayleigh-Plesset-Keller-Kolodner equation, the dynamics of single bubble is calculated regarding water as work medium in the conditions of different ratio of inlet pressure and outlet pressure. The flow field in venturi is simulated by fluid dynamics. The results show that the velocity in throat location and maximum cavitation volume fraction increase with ratio of inlet pressure and outlet pressure increasing. The area of cavitation extends. The pressure in throat location reduces and then become stable. The maximum growth rate of single bubble and pressure pulse in bubble increase significantly. The recurrence times of growth and collapsing increases. The influence of single bubble dynamics on the distribution of the whole flow field depends on the turbulence intensity. The more severe the turbulence in venture, the less the effect of single bubble on the whole flow field.
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