channel variation
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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.


2019 ◽  
Vol 8 (2S11) ◽  
pp. 3075-3077

With the advancement of remote correspondence, the confinement of sign estimation under channel variation condition and their belongings were expanding. Different systems were proposed in past for the improvement of sign estimation effectiveness dependent on reference data utilizing versatile, visually impaired or semi visually impaired methodologies. Where visually impaired and semi visually impaired are seen to beat the versatile based methodologies, further upgrades are still on research to improve the productivity with least time union. To accomplish this goal, estimation calculations in time, recurrence and time-recurrence area were created. These methodologies attempt to accomplish the productivity targets by either expanding the estimation recursion or restricting the mistake likelihood. This paper exhibits a methodology for accomplishing improved estimation proficiency with least time assembly and lesser mistake likelihood, in MIMO correspondence framework utilizing the kalman filtration approach. A ghastly estimation rationale dependent on vitality of the sign range is made.


Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 483 ◽  
Author(s):  
Marianne Laslier ◽  
Laurence Hubert-Moy ◽  
Simon Dufour

Riparian zones experience many anthropic pressures and are the subject of European legislation to encourage their monitoring and management, to attenuate these pressures. Assessing the effectiveness of management practices requires producing indicators of ecological functions. Laser Detection and Ranging (LiDAR) data can provide valuable information to assess the ecological status of riparian zones. The objective of this study was to evaluate the potential of LiDAR point clouds to produce indicators of riparian zone status. We used 3D bispectral LiDAR data to produce several indicators of a riparian zone of a dammed river in Normandy (France). The indicators were produced either directly from the 3D point clouds (e.g., biomass overhanging the channel, variation in canopy height) or indirectly, by applying the Random Forest classification algorithm to the point clouds. Results highlight the potential of 3D LiDAR point clouds to produce indicators with sufficient accuracy (ca. 80% for the number of trunks and 68% for species composition). Our results also reveal advantages of using metrics related to the internal structure of trees, such as penetration indexes. However, intensity metrics calculated using bispectral properties of LiDAR did not improve the quality of classifications. Longitudinal analysis of the indicators revealed a difference in attributes between the reservoir and areas downstream from it.


2019 ◽  
Vol 9 (5) ◽  
pp. 886
Author(s):  
Chao Wang ◽  
Jianhua Zhang ◽  
Guangzhong Yu

In wireless communication systems, channels evolve when user terminals move. To further understand channel variation, and especially the evolution of clusters in mobile channels, a set of experiments was designed. First, we performed pedestrian mobile measurements in an urban macro (UMa) scenario at 3.5 GHz, and the K-power means-Kalman filter (KPMKF) algorithm was used for clustering and tracking. By this process, the trajectory of different clusters could clearly be described during measurement. The birth and death rate of clusters per snapshot show that the change of one or two clusters in each snapshot takes more probabilities. In addition, the differences of the cluster lifetime between the clustering process with and without the Kalman filter (KF) algorithm are given to show the effect from the KF. Second, channel simulations were implemented based on the above observed results. The spatial-consistency feature was introduced to get closer to the measured channels, which is based on the primary module of International Mobile Telecommunications-2020 (IMT-2020) channel model. Comparisons among measurements and simulations with and without this feature show that adding this feature improves simulation accuracy. To explore a novel method to characterize clusters during linear movement, a gradient boosted decision-tree (GBDT) algorithm is introduced. It uses the above characteristics of clusters and channel impulse responses (CIRs) as the training and validating dataset. The root mean square error (RMSE) shows that this is promising.


2018 ◽  
Vol 6 (3) ◽  
pp. 763-778 ◽  
Author(s):  
Jasper R. F. W. Leuven ◽  
Sanja Selaković ◽  
Maarten G. Kleinhans

Abstract. Fluvial–tidal transitions in estuaries are used as major shipping fairways and are characterised by complex bar and channel patterns with a large biodiversity. Habitat suitability assessment and the study of interactions between morphology and ecology therefore require bathymetric data. While imagery offers data of planform estuary dimensions, only for a few natural estuaries are bathymetries available. Here we study the empirical relation between along-channel planform geometry, obtained as the outline from imagery, and hypsometry, which characterises the distribution of along-channel and cross-channel bed levels. We fitted the original function of Strahler (1952) to bathymetric data along four natural estuaries. Comparison to planform estuary shape shows that hypsometry is concave at narrow sections with large channels, while complex bar morphology results in more convex hypsometry. We found an empirical relation between the hypsometric function shape and the degree to which the estuary width deviates from an ideal convergent estuary, which is calculated from river width and mouth width. This implies that the occurring bed-level distributions depend on inherited Holocene topography and lithology. Our new empirical function predicts hypsometry and along-channel variation in intertidal and subtidal width. A combination with the tidal amplitude allows for an estimate of inundation duration. The validation of the results on available bathymetry shows that predictions of intertidal and subtidal area are accurate within a factor of 2 for estuaries of different size and character. Locations with major human influence deviate from the general trends because dredging, dumping, land reclamation and other engineering measures cause local deviations from the expected bed-level distributions. The bathymetry predictor can be used to characterise and predict estuarine subtidal and intertidal morphology in data-poor environments.


2018 ◽  
Author(s):  
Jasper R. F. W. Leuven ◽  
Sanja Selaković ◽  
Maarten G. Kleinhans

Abstract. Fluvial-tidal transitions in estuaries are used as major shipping fairways and are characterised by complex bar and channel patterns with a large biodiversity. Habitat suitability assessment and study of interactions between morphology and ecology therefore require bathymetric data. While imagery offers data of planform estuary dimensions, only for a few natural estuaries bathymetries are available. Here we study the relation between along-channel planform geometry, obtained as the outline from imagery, and hypsometry, which characterises the distribution of along-channel and cross-channel bed-levels. We fitted the original function of Strahler (1952) to bathymetric data along four natural estuaries. Comparison to planform estuary shape shows that hypsometry is concave at narrow sections with large channels, while complex bar morphology results in more convex hypsometry. We found a relation between hypsometric function shape and the degree to which the estuary width deviates from an ideal convergent estuary, which is calculated from river width and mouth width. This implies that the occurring bed level distributions depend on inherited Holocene topography and lithology. Our new empirical function predicts hypsometry and along-channel variation in intertidal and subtidal width. Combination with the tidal amplitude allows an estimate of inundation duration. A validation of the results on available bathymetry shows that predictions of intertidal and subtidal area are accurate within a factor 2 for estuaries of different size and character. Locations with major human influence deviate from the general trends, because dredging, dumping, land reclamation and other engineering measures cause local deviations from the expected bed-level distributions. The bathymetry predictor can be used to characterise and predict estuarine subtidal and intertidal morphology in data-poor environments.


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