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1. Online Millimeter Wave Phased Array Calibration Based on Channel Estimation

   https://doi.org/10.1109/MDAT.2020.2968286  

   Moon, Thomas; Gaun, Junfeng; Hassanieh, Haitham (January 2020, IEEE Design & Test)

   This article introduces a new over-the-air calibration method for millimeter wave phased arrays. Our method leverages the channel estimation process which is a fundamental part of any wireless communication system. By performing the channel estimation while changing the phase of an antenna element, the response of the element is obtained. Unlike prior work, our method includes all the system components and thus, spans the full chain. By overriding channel estimation, no additional circuits are required, and online calibration is possible without pausing the communication process. We tested our method on an eight-element-phased array at 24GHz which we designed and fabricated in PCB for verification. 

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2. New remote method to systematically extract bedrock channel width of small catchments across large spatial scales using high‐resolution digital elevation models

   https://doi.org/10.1002/esp.5560  

   Eidmann, Johanna Sophie; Gallen, Sean (February 2023, Earth Surface Processes and Landforms)

   Abstract Bedrock river width is an essential geometric parameter relevant to understanding flood hazards and gauging station rating curves, and is critical to stream power incision models and many other landscape evolution models. Obtaining bedrock river width measurements, however, typically requires extensive field campaigns that take place in rugged and steep topography where river access is often physically challenging. Although prior work has turned to measuring channel width from satellite imagery, these data present a snapshot in time, are typically limited to rivers ≥ 10–30 m wide due to the image resolution, and are physically restricted to areas devoid of vegetation. For these reasons, we are generally data limited, and the factors impacting bedrock channel width remain poorly understood. Due to these limitations, researchers often turn to assumptions of width‐scaling relationships with drainage area or discharge to estimate bedrock channel width. Here we present a new method of obtaining bedrock channel width at a desired river discharge through the incorporation of a high‐resolution bare‐earth digital elevation model (DEM) using MATLAB Topotoolbox and the HEC‐RAS river analysis system. We validate this method by comparing modeled results to US Geological Survey (USGS) field measurements at existing gauging stations, as well as field channel measurements. We show that this method can capture general characteristics of discharge rating curves and predict field‐measured channel widths within uncertainty. As high‐resolution DEMs become more available across the United States through the USGS three‐dimensional elevation program (3DEP), the future utility of this method is notable. Through developing and validating a streamlined, open‐source, and freely available workflow of channel width extraction, we hope this method can be applied to future research to improve the quantity of channel width measurements and improve our understanding of bedrock channels. 

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3. A method to detect abrupt shifts in river channel position using a Landsat‐derived water occurrence record

   https://doi.org/10.1002/esp.5472  

   Lee, Dylan B.; Martin, Harrison K.; Edmonds, Douglas A. (September 2022, Earth Surface Processes and Landforms)

   Abstract The lateral migration of river channels is an important control on the evolution of alluvial fans, deltas, and floodplains. Lateral migration consists of both gradual riverbank migration and abrupt shifts in location due to avulsions or cutoffs. Methods exist to measure bank migration, but abrupt shifts in position are rarely considered or are not emphasized. Here we describe a new method using Landsat‐derived water occurrence images that primarily focuses on detecting when a channel has abruptly shifted position, either from avulsion or cutoff. The method does not assume any a priori model of channel geometry or evolution. Within a given area of interest, binary channel images created from the fluvial water occurrence record are stacked through time. Then a channel shift intensity, , is created by estimating the number of possible ending times for fluvial water voxels (a point in three‐dimensional space) in the stacked occurrence record. The number of possible end‐times for fluvial water voxels within a given region of the occurrence record reveals the likelihood that a reach of a river underwent an abrupt channel shift during the observation period. We present the results of this analysis for a 194 481 km²region of the Amazonian basin. Follow‐up validation found three avulsions and 270 cutoffs within regions identified by this method. We show that areas above a threshold contain an avulsion or cutoff with high probability. This highlights the method's potential to detect and quantify abrupt channel shifts at the basin scale. The method also successfully distinguishes between abrupt channel movement and complex braiding behaviour. As this method is applicable to any binary water‐masked time series images, future applications of this method have the potential to provide insight into the controls and spatial variance of avulsions and cutoffs across a variety of scales. 

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4. Channel Pruning for Deep Neural Networks via a Relaxed Groupwise Splitting Method

   https://doi.org/DOI 10.1109/AI4I.2019.0003  

   Biao Yang, Jack Xin (October 2019, 2019 Second International Conference on Artificial Intelligence for Industries (AI4I))

   null (Ed.)

   A relaxed groupwise splitting method (RGSM) is developed and evaluated for channel pruning of deep neural networks. Experiments with VGG-16 and ResNet-18 architectures on CIFAR-10/100 image data show that RGSM can achieve much higher channel sparsity than group Lasso method, while keeping comparable accuracy 

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5. Residual self-interference cancellation and data detection in full-duplex communication systems

   https://doi.org/10.1109/ICC.2017.7997326  

   Koohian, Abbas; Mehrpouyan, Hani; Nasir, Ali Arshad; Durrani, Salman; Blostein, Steven D. (January 2017, IEEE International Conference on Communicaitons)

   Residual self-interference cancellation is an important practical requirement for realizing the full potential of full-duplex (FD) communication. Traditionally, the residual self-interference is cancelled via digital processing at the baseband, which requires accurate knowledge of channel estimates of the desired and self-interference channels. In this work, we consider point-to-point FD communication and propose a superimposed signaling technique to cancel the residual self-interference and detect the data without estimating the unknown channels. We show that when the channel estimates are not available, data detection in FD communication results in ambiguity if the modulation constellation is symmetric around the origin. We demonstrate that this ambiguity can be resolved by superimposed signalling, i.e., by shifting the modulation constellation away from the origin, to create an asymmetric modulation constellation. We compare the performance of the proposed detection method to that of the conventional channel estimation-based detection method, where the unknown channels are first estimated and then the data signal is detected. Simulations show that for the same average energy over a transmission block, the bit error rate performance of the proposed detection method is better than that of the conventional method. The proposed method does not require any channel estimates and is bandwidth efficient. 

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