Local density distribution in a new FCC feed injection scheme

2014 ◽  
pp. 337-342
Keyword(s):  
Density Distribution ◽  
Local Density ◽  
Injection Scheme

scholarly journals An Improved K-means Method with Density Distribution Analysis

2018 ◽  
Vol 176 ◽  
pp. 01019
Author(s):  
Huiwen Xue ◽  
Haochen Li ◽  
Yanfei Wang
Keyword(s):  
Density Distribution ◽  
Clustering Algorithm ◽  
Local Density ◽  
Synthetic Data ◽  
Original Data ◽  
Cluster Center ◽  
Distribution Analysis ◽  
Time Cost ◽  
Improved Method ◽  
Business Data

In this paper, a novel K-means clustering algorithm is proposed. Before running the traditional Kmeans, the cluster centers should be randomly selected, which would influence the time cost and accuracy. To solve this problem, we utilize density distribution analysis in the traditional K-means. For a reasonable cluster, it should have a dense inside structure which means the points in the same cluster should tightly surround the center, while separated away from other cluster canters. Based on this assumption, two quantities are firstly introduced: the local density of cluster center ρi and its desperation degree δi, then some reasonable cluster centers candidates are selected from the original data. We performed our algorithm on three synthetic data and a real bank business data to evaluate its accuracy and efficiency. Comparing with Traditional K-means and K-means++, the results demonstrated that the improved method performs better.

A Method to Determine the Effect of Microscale Heterogeneities on Macroscopic Web Mechanics

2004 ◽  
Vol 72 (3) ◽  
pp. 365-373
Author(s):  
Lewis Thigpen ◽  
Patrick T. Reardon ◽  
Jeremy W. Leggoe ◽  
Alan L. Graham ◽  
Mark Fitzgerald
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Spatial Heterogeneity ◽  
Density Distribution ◽  
Local Density ◽  
Manufacturing Defects ◽  
Modeling Approach ◽  
Local Material ◽  
Roller System ◽  
The Web

The effect of a spatially heterogeneous density distribution on the development of defects during the transport of nonwoven webs through roller systems has been investigated numerically. A modeling approach has been developed by which the spatial heterogeneity in web mechanical properties can be characterized statistically and recreated for use in finite element simulations. The approach has been applied to model the transport of a carded nonwoven web, consisting of an agglomeration of polypropylene fibers bound together by a regular array of thermal bond points. The web was scanned optically to obtain a gray scale light distribution representing the local material density. Analysis of the local density distribution permitted the generation of “virtual webs” for use in heterogeneous finite element models, in which local mechanical properties were governed by local density. Virtual web response was investigated under two loading configurations; simple tensile testing, and web transport under tension through a three-roller system. The modeling approach provided results that were in good agreement with experimentally observed web mechanics, failure mechanisms, and processing instabilities. Spatial heterogeneity in material properties was found to strongly influence both general web behavior and the tendency for the web to incur manufacturing defects during transport through roller systems.

Sign in / Sign up

Export Citation Format

Share Document