Accurate segmentation of Whole Slide Image (WSI) remains a significant challenge in medical image analysis. Current methods often struggle with effective feature extraction and precise segmentation. To address these, this paper introduces a convolutional neural network, MSAF-UNet, which extracts and fuses color features and texture features. The model employs edge detection operator and Otsu algorithm to highlight texture details, then use K-means clustering and median filtering to highlight color details. The Multi-Scale Attention Fusion (MSAF) module cross-splices the feature maps and integrates the highlighted features through global and local attention branches. Additionally, K-means clustering and Generalized Hough Transform (GHT) methods reduce manual annotation effort while improving segmentation accuracy. Comprehensive comparative experiments and ablation experiments on the CAMELYON16&17 and EBHI-Seg datasets demonstrate that the performance of the proposed method achieved state-of-the-art, verifying the advantages of the proposed method demonstrate that the proposed model outperforms other representative models with 1)an average improvement of 2.27% and reached 94.5% in accuracy; 2)a sound adaptability to support varying image data.

A User Equipment (UE) beamforming method is proposed for massive MIMO based stratospheric communications with multiple High Altitude Platforms (HAPs). The method leverages multiple-antenna UEs to mitigate interference from neighboring HAPs. No additional channel information exchange between UEs and HAPs is needed. The beamforming vector is obtained at the UE side by using the semi-definite relaxation based method. Both the Rician channel model and the HAP- MIMO channel model based on the dynamic evolution of scatters are adopted. Simulations under various environmental configurations demonstrate the performance improvement of the proposed method.

With Massive MIMO installed on High Altitude Platforms (HAPs), capacity analysis is conducted for both sparse users and hotspot users. Sparse users are assumed to follow the Poisson Point Process and their capacities are obtained via the random geometry theorem. For hotspot users, Massive MIMO combined with HAP-based communication is shown to be able to achieve the multiplexing gain thus increase the hotspot capacity. The channel correlation model of UPA under LOS propagations is obtained for users within the hotspot. An upper bound of the correlation function is further derived to show that the correlation between hotspot users can be sufficiently low, resulting in hotspot capacity improvement. The hotspot capacity is affected by location distributions of the scheduled users. Four user location distribution models are considered, which leads to the capacity upper bound, the practical schemes to implement and the capacity estimation method respectively.

This paper proposes a three-dimensional (3-D) multiuser channel model for stratospheric multipath-fading channel. The birth-death process is used to model the non-stationary properties that scatterers “appear” and “disappear” on the array axes. The spatial correlation of multiuser High Altitude Platform (HAP) multiple-input multiple-output (MIMO) channel is investigated in this paper. This model can be used to estimate the acquired antenna separation at Stratospheric Base Station (SBS) and user to achieve uncorrelated channel matrix between two adjacent users. Numerical results show that the proposed model is able to capture characteristics as observed in measurements.

In massive multiple-input multiple-output (MIMO) systems, the effect of small-scale fading and noise disappear when the number of base station antennas goes to infinity. The only remaining impairment is pilot contamination. In this paper, interference mitigation method is proposed by leveraging the dual antenna user equipments. Given the antenna correlation matrix at the user side, the optimal beamforming weight is obtained explicitly. Using the proposed beamforming weight, the interference are reduced during both the uplink pilot transmission and the downlink data transmission, thus the cell capacity is improved. Simulations under various environmental configurations verify the capacity improvements.

Content Security Policy CSP is a popular and effective security mechanism against content injection vulnerabilities such as cross-site scripting for web applications. Unfortunately, there are many problems in analysis, design, and evaluation of CSP, which are hindering the wide adoption of CSP by real-world web applications. In this paper, we give a systematic study and propose workable solutions for these problems. We systemically analyze the methodology of CSP, namely how it works and prevents attacks. We present the security weaknesses in the methodology, namely which attacks it cannot prevent. We give the formalized definitions and proofs of the properties for theoretically accurate design and evaluation of CSP in web applications. We give a practical policy tool named ACSP to help developers or analysts to automatically design CSP with the best security and availability or exactly evaluate the security and availability of the used CSP in one or a number of web pages. We perform a large scale evaluation of the CSP policies in real-world applications. The most serious problem that we find out is that their policies only leverage a small part of security ability of CSP. Copyright © 2016 John Wiley & Sons, Ltd.

In wireless sensor networks (WSNs), keeping all sensor nodes connected to the sink for collecting data is very important. Nonetheless, when some sensor nodes fail due to emergencies, the connection may be lost and the network may be partitioned into several isolated segments. To restore the connections between each segment and the sink in order to gather the measured data, relay nodes need placing properly in the gap regions. Besides, we usually would like to keep the connectivity for a certain period of time in the real scene. However, obtaining the minimal number, the optimal positions and the optimal transmission power of the placed relay nodes subjected to the network lifetime requirement is NP-hard and heuristics are thus pursued. In this paper, we propose a distributed and energy efficient algorithm, Relay node Placement with Guaranteed Lifetime (RPGL), to reconnect the network while demanding minimal relay nodes subjected to that the network will not be partitioned again due to the failure of the relay nodes within the required time. Simulation results not only verify the theoretical analysis but also show that the number of the relay nodes required is less than the other efficient algorithms in the references.