Randomized Polar Subcodes With Optimized Error Coefficient

2020 ◽  
Vol 68 (11) ◽  
pp. 6714-6722
Author(s):  
Peter Trifonov
Keyword(s):  
1968 ◽  
Vol 32 (1) ◽  
pp. 122 ◽  
Author(s):  
G. Ray Funkhouser ◽  
Edwin B. Parker

Author(s):  
M.K Bowen ◽  
Ronald Smith

Lagrange interpolation estimates a function at a reference position Χ from known values of the function at distinct non-uniformly spaced points x 1 , …, x n . Here, the corresponding n -point finite-difference formulae are derived to estimate derivatives up to order n −1 at Χ . A recurrence relation is derived that permits the errors to be determined as a Taylor series to any accuracy. The error coefficient multiplying the n + j th derivative is a polynomial of order j +1 in the elementary symmetric functions for the displacements x 1 − Χ ,…, x n − Χ . Appendices state finite-difference formulae to estimate the derivatives and the first four error terms for n =1,…,5.


2020 ◽  
Vol 71 (4) ◽  
pp. 561-570
Author(s):  
Siheng Sun ◽  
Guozhong Huang ◽  
Jiaran Cai ◽  
Dong Jiang

The reuse of wastewater improves the comprehensive utilization of water resources, and reduces the shortage of water resources. In this paper, the accumulation of heavy metal Cd risk in reclaimed water irrigated soil to human health was analysised through experiments and simulations. Firstly, according to the static adsorption experiment of sandy clay loam, the fitting effect of Freundlich equation on Cd is better for the certainty coefficient R2 reaches 0.97. Then, use the more accurate DEM model of CXTFIT2.1 software to fit the Cl- penetration curve. Finally, made the heavy metal leading experiment, found that the TSM model has a good fitting effect on the penetration curve of Cd, with a determination coefficient close to 1 and a small standard error coefficient. Based on the results of the above experiments, the HYDRUS-1D was used to analyze and predict the cumulative risk of Cd in reclaimed water irrigated soil. The results showed that: after 100 years under current situations, the predicted concentration of Cd in soil may reach 0.742 mg/kg, which exceeded the national soil environmental quality standard, may be a serious health hazard. Measures should be taken to reduce the risk of human health by ingestion and accumulation of crops and vegetables.


BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5417-5432
Author(s):  
Chao Li ◽  
Xilong Wang ◽  
Yizhuo Zhang

To explore the overall mechanical properties of bamboo-wood composite cross-laminated timber (BCLT), a simulation model of BCLT mechanical behavior based on the solid element was established using the finite element software ABAQUS. The actual four-point bending experiment was compared and analyzed with the finite element numerical simulation. The total curve error coefficient of the BCLT specimen at 18-mm displacement was 0.2988 while the interval was 0.5 mm. The error coefficient was 0.0178 when the maximum load was reached, and the minimum error coefficient was 0.0015 at 12 mm of displacement. Analysis of the influence of material parameters, meshing density, and material arrangement on the final stress distribution indicate that the difference in the elastic parameters of the material greatly influence the final stress distribution, and the arrangement and combination of materials also have an effect on the overall mechanical properties of the BCLT board. The combination CLT1-2-1 (i.e., the upper and lower layers of the bamboo are Arrangement 1 and the hemlock is Arrangement 2) have a maximum load of 57682 Ν and a maximum stress of 103.9 MPa.


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