HYDRAULIC EXPERIMENTS ON THE INFLUENCE OF SEDIMENTATION AROUND A LOW WATER REVETMENT OR SPUR DIKE TO CHANNEL VARIATION

Author(s):  
Satomi YAMAGUCHI ◽  
Tomoko KYUKA
Keyword(s):  
Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1104
Author(s):  
Siti Raihanah Abdani ◽  
Mohd Asyraf Zulkifley ◽  
Nuraisyah Hani Zulkifley

Pterygium is an eye condition that is prevalent among workers that are frequently exposed to sunlight radiation. However, most of them are not aware of this condition, which motivates many volunteers to set up health awareness booths to give them free health screening. As a result, a screening tool that can be operated on various platforms is needed to support the automated pterygium assessment. One of the crucial functions of this assessment is to extract the infected regions, which directly correlates with the severity levels. Hence, Group-PPM-Net is proposed by integrating a spatial pyramid pooling module (PPM) and group convolution to the deep learning segmentation network. The system uses a standard mobile phone camera input, which is then fed to a modified encoder-decoder convolutional neural network, inspired by a Fully Convolutional Dense Network that consists of a total of 11 dense blocks. A PPM is integrated into the network because of its multi-scale capability, which is useful for multi-scale tissue extraction. The shape of the tissues remains relatively constant, but the size will differ according to the severity levels. Moreover, group and shuffle convolution modules are also integrated at the decoder side of Group-PPM-Net by placing them at the starting layer of each dense block. The addition of these modules allows better correlation among the filters in each group, while the shuffle process increases channel variation that the filters can learn from. The results show that the proposed method obtains mean accuracy, mean intersection over union, Hausdorff distance, and Jaccard index performances of 0.9330, 0.8640, 11.5474, and 0.7966, respectively.


2016 ◽  
pp. 193-199
Author(s):  
S.Y. Hao ◽  
Y.F. Xia ◽  
H. Xu
Keyword(s):  

2017 ◽  
pp. 145-150
Author(s):  
H.X. Liu ◽  
M.C. Zhu ◽  
T.J. Huang ◽  
Y.J. Lu

2013 ◽  
Vol 405-408 ◽  
pp. 799-802
Author(s):  
Hui Xu ◽  
Ming Zhang ◽  
Wan Qi Zhang

A three-dimensional (3D) flow mathematical model has been applied to simulate the flow field around spur dikes. In the vertical plane, the z-coordinate was adopted, and the additional layer was used to track the free water surface. The standard k-ε model was adopted, additionally, wall function and large coefficient method was applied to treat the boundary of the spur dike. Simulated results of velocity distribution, turbulent kinetic energy and its dissipation rate around the spur dike agree well with the experimental data.


2018 ◽  
Vol 25 (3) ◽  
pp. 671-680 ◽  
Author(s):  
Mohammad Vaghefi ◽  
Arash Ahmadi ◽  
Behroz Faraji

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1417 ◽  
Author(s):  
Manish Pandey ◽  
Wei Haur Lam ◽  
Yonggang Cui ◽  
Mohammad Amir Khan ◽  
Umesh Kumar Singh ◽  
...  

Scour is the main cause of failure for spur dike. The accurate prediction of scour around spur dike is essential to design a spur dike. The present study focuses on the maximum scour depth in equilibrium condition and parameters, which influence it in a sand–gravel mixture bed. Outcomes of the present experimental study showed that the non-dimensional maximum equilibrium scour depth increases with critical velocity ratio (U/Uca), water depth-armour particle ratio (h/da), Froude number for sediment mixture (Frsm), water depth-spur dike length ratio (h/l), and decreases with increase in armour particle-spur dike length ratio (da/l). The maximum scour depth is proportional to dimensionless parameters of U/Uca, h/da, Frsm, h/l, but the scour depth is inverse proportional to da/l. Scour around spur dike in a sand–gravel mixture is mainly influenced by the property of the sediment mixture. The scour increases with decrease in non-uniformity of the sediment mixture. A non-linear empirical equation is proposed to estimate the maximum scour depth at an upstream nose of rectangular spur dike with a maximum error of 15%. The sensitivity analysis indicates that the maximum non-dimensional equilibrium scour depth depends on Frsm, followed by the secondary sensible parameters da/l, h/l, and h/da.


Sign in / Sign up

Export Citation Format

Share Document