In the field of biomedicine, advances in high-throughput sequencing have generated vast amounts of high-dimensional multi-omics data. Survival analysis methods with multi-omics data can comprehensively uncover the heterogeneity and complexity of diseases from multiple perspectives, thereby improving prognostic predictions for patients, which is critical for developing personalized treatment strategies in precision medicine. Recently, Transformer architecture has emerged as a dominant paradigm in multiple domains. However, due to the inherent challenges in modeling right-censored data, it remains unclear how to effectively utilize Transformer architecture in multi-omics survival analysis to fully extract complementary information across different omics for improving survival prediction performance. In this work, we propose an innovative collaborative Transformer framework for multi-omics survival analysis, namely CoFormerSurv, with two consecutive Transformer architectures including an inter-omics Transformer and an inter-sample graph Transformer. The inter-omics Transformer learns multiple meaningful feature interactions by multi-head self-attention mechanism to capture and quantify complementary information across different omics, while the inter-sample graph Transformer integrates structural information from the fused multi-omics graph into the Transformer architecture, enabling more effective exploration of neighborhood relationships among samples. The two kinds of Transformer architectures can work collaboratively to generate more comprehensive multi-omics features for improving the Cox-PH model performance in survival analysis. Experimental results on multiple real-world datasets show that our proposed method outperforms both single-Transformer architectures and existing survival prediction models by simultaneously exploring complementary information from inter-omics and cross-sample perspectives.

Multi-omics data often suffer from the "big $p$, small $n$" problem where the dimensionality of features is significantly larger than the sample size, making the integration of multi-omics data for survival analysis of a specific cancer particularly challenging. One common strategy is to share multi-omics data from other related cancers across multiple institutions and leverage the abundant data from these cancers to enhance survival predictions for the target cancer. However, due to data privacy and data-sharing regulations, it is challenging to aggregate multi-omics data of related cancers from multiple institutions into a centralized database to learn more accurate and robust models for the target cancer. To address the limitation, we propose a multi-omics survival prediction model with self-attention mechanism (MOSAHit), trained within a federated transfer learning framework with differential privacy. This approach enables the learning of a more robust multi-omics survival prediction model for a local target cancer with limited training data by effectively leveraging multi-omics data of related cancers distributed across multiple institutions while preserving individual privacy. Results from the comprehensive experiments on real-world datasets show that the proposed method effectively alleviates data insufficiency and significantly improves the generalization performance of multi-omics survival prediction model for a target cancer while avoiding the direct sharing of multi-omics data for related cancers.

MOTIVATION: High-throughput techniques have produced a large amount of high-dimensional multi-omics data, which makes it promising to predict patient survival outcomes more accurately. Recent work has showed the superiority of multi-omics data in survival analysis. However, it remains challenging to integrate multi-omics data to solve few-shot survival prediction problem, with only a few available training samples, especially for rare cancers. RESULTS: In this work, we propose a meta-learning framework for multi-omics few-shot survival analysis, namely MMOSurv, which enables to learn an effective multi-omics survival prediction model from a very few training samples of a specific cancer type, with the meta-knowledge across tasks from relevant cancer types. By assuming a deep Cox survival model with multiple omics, MMOSurv first learns an adaptable parameter initialization for the multi-omics survival model from abundant data of relevant cancers, and then adapts the parameters quickly and efficiently for the target cancer task with a very few training samples. Our experiments on eleven cancer types in The Cancer Genome Atlas datasets show that, compared to single-omics meta-learning methods, MMOSurv can better utilize the meta-information of similarities and relationships between different omics data from relevant cancer datasets to improve survival prediction of the target cancer with a very few multi-omics training samples. Furthermore, MMOSurv achieves better prediction performance than other state-of-the-art strategies such as multitask learning and pretraining. AVAILABILITY AND IMPLEMENTATION: MMOSurv is freely available at https://github.com/LiminLi-xjtu/MMOSurv.

Abstract It is very challenging to accurately segment smoke images because smoke has some adverse vision characteristics, such as anomalous shapes, blurred edges, and translucency. Existing methods cannot fully focus on the texture details of anomalous shapes and blurred edges simultaneously. To solve these problems, a Dense Multi‐scale context and Asymmetric pooling Embedding Network (DMAENet) is proposed to model the smoke edge details and anomalous shapes for smoke segmentation. To capture the feature information from different scales, a Dense Multi‐scale Context Module (DMCM) is proposed to further enhance the feature representation capability of our network under the help of asymmetric convolutions. To efficiently extract features for long‐shaped objects, the authors use asymmetric pooling to propose an Asymmetric Pooling Enhancement Module (APEM). The vertical and horizontal pooling methods are responsible for enhancing features of irregular objects. Finally, a Feature Fusion Module (FFM) is designed, which accepts three inputs for improving performance. Low and high‐level features are fused by pixel‐wise summing, and then the summed feature maps are further enhanced in an attention manner. Experimental results on synthetic and real smoke datasets validate that all these modules can improve performance, and the proposed DMAENet obviously outperforms existing state‐of‐the‐art methods.

MOTIVATION: Survival analysis is an important tool for modeling time-to-event data, e.g. to predict the survival time of patient after a cancer diagnosis or a certain treatment. While deep neural networks work well in standard prediction tasks, it is still unclear how to best utilize these deep models in survival analysis due to the difficulty of modeling right censored data, especially for multi-omics data. Although existing methods have shown the advantage of multi-omics integration in survival prediction, it remains challenging to extract complementary information from different omics and improve the prediction accuracy. RESULTS: In this work, we propose a novel multi-omics deep survival prediction approach by dually fused graph convolutional network (GCN) named FGCNSurv. Our FGCNSurv is a complete generative model from multi-omics data to survival outcome of patients, including feature fusion by a factorized bilinear model, graph fusion of multiple graphs, higher-level feature extraction by GCN and survival prediction by a Cox proportional hazard model. The factorized bilinear model enables to capture cross-omics features and quantify complex relations from multi-omics data. By fusing single-omics features and the cross-omics features, and simultaneously fusing multiple graphs from different omics, GCN with the generated dually fused graph could capture higher-level features for computing the survival loss in the Cox-PH model. Comprehensive experimental results on real-world datasets with gene expression and microRNA expression data show that the proposed FGCNSurv method outperforms existing survival prediction methods, and imply its ability to extract complementary information for survival prediction from multi-omics data. AVAILABILITY AND IMPLEMENTATION: The codes are freely available at https://github.com/LiminLi-xjtu/FGCNSurv.

The fundamental issue of how to calculate the false positive probability of widely used Bloom Filters (BF), from which the conventional wisdom is to derive the optimal value of$k$, remains elusive. Since Bloom gave the false positive formula in 1970, in 2008, Boseet al. pointed out that Bloomˆs formula is flawed; and in 2010, Christensenet al. pointed out that Bose's formula is also flawed and gave another formula. Although Christensen's formula is perfectly accurate, it is time-consuming and impossible to calculate the optimal value of$k$. Based on the following observation: for a BF with$m$bits and$n$elements, if and only if its entropy is the largest, its false positive probability is the smallest, we propose the first approach to calculating the optimal$k$without any false positive formula. Furthermore, we propose a new and more accurate upper bound for the false positive probability. When the size of a Bloom Filter becomes infinitely large, our upper bound turns equal to the lower bound, which becomes Bloomˆs formula and deepens our understanding towards it. Besides, we derive the bounds of correct rate of Counting Bloom Filters (CBFs) by applying our proposed formulas about BFs to them.

In this paper, we study periodic items in data streams, which refer to those items arriving with a fixed interval. All existing works involving mining periodic patterns does not fit for data stream scenarios. To find periodic items in real time, we propose a novel sketch, PeriodicSketch, aiming to accurately record top-$K$periodic items. To the best of our knowledge, this is the first work to find periodic items in data streams. Any interval may occur many times, and we use frequency to denote the number of an interval occurred. To pick out periodic items with high frequency, we propose a key technique called Guaranteed Soft Uniform (GSU) replacement strategy. Our theoretical proofs show that when replacement is successful, it is more likely that the new item has a higher frequency than the current smallest frequency; and GSU can ensure that our items in the sketch will approach the true periodic items closer and closer. And as soon as we get all the periodic items, the state would not change worse with high probability. We conduct extensive experiments, and the experimental results show that the Average Absolute Error (AAE) of our sketch using 1/10 memory is around 737 times (up to 2019 times) lower than the baseline solution. Finally, we provide a concrete case: Cache prefetch, which proves that PeriodicSketch can significantly improve the Cache hit ratio. All related codes of PeriodicSketch are open-sourced and available at GitHub [1].

Satellite detection has been an advantageous method in wildfire detection for its near-real-time monitoring and large coverage. In this paper, a time scale base wildfire detection is proposed based on himawari-8 satellite data. Firstly, we used adjusted Otsu algorithm to remove the cloud mask. Afterwards, 7 previous data of each 10 minutes before the current time of a pixel is input into a Long Short Term (LSTM) network to predict current data. Finally, the predicted data was compared with the ground truth to determine fire. The result showed a high accuracy in prediction and better performance in determining wildfire compared with traditional dynamic threshold method. The experiment is limited by the time of the selected wildfire data and expected to test the performance over different period.

The potential safety hazards for the power grid caused by explosion of insulators occur again and again. Thus, the detecting and monitoring of insulators on the transmission towers is vital. In the paper, a novel method was proposed to detect insulators with high resolution satellites images. First, the SuperView-1 (0.5 m) and WorldView-3 (0.3 m) scenes of Yunnan were gathered, and then gram-schmidt method was used to fusion the original images. Second, a wide deep super resolution network (WDSR) is used to enhance the images resolution by 4 times. Third, fake color output and 1% linear stretched were applied to enhance image detail. Then, an object detection neural network based on feature pyramid networks (FPN) was used to detect transmission tower. Finally, a high-resolution network (HR-Net) was used to detect insulators on the tower. For comparison, three different class weight calculation methods and online hard example mining (OHEM) training methods of HR-Net were also proposed. HR-Net-c2-ohem final achieved highest 0.8001 of F1-Score. Therefore, our proposed method is robust to detect the insulators of transmission line tower with high resolution satellites images.

When deploying network nodes, there are many redundant nodes, low network coverage and high energy consumption of network nodes, the node deployment method of wireless sensor networks(WSN) based on mobile edge computing is studied. WSN nodes are divided into anchor nodes and unknown nodes. Taking the location information of anchor nodes as a reference, the specific location of unknown nodes is obtained by trilateral measurement. Minimizing the node distance error is taken as the objective function, and the cuckoo search algorithm is used to solve it to obtain the final location result of the node. The mobile edge computing method is used to design the node deployment method of WSN to complete the node deployment. Simulation results show that the number of redundant nodes in this method is 3, maximum network coverage is 89%, maximum energy consumption of network nodes is 34.3J.