244 research outputs found
Routing Protocols for Underwater Acoustic Sensor Networks: A Survey from an Application Perspective
Underwater acoustic communications are different from terrestrial radio communications; acoustic channel is asymmetric and has large and variable endâtoâend propagation delays, distanceâdependent limited bandwidth, high bit error rates, and multiâpath fading. Besides, nodesâ mobility and limited battery power also cause problems for networking protocol design. Among them, routing in underwater acoustic networks is a challenging task, and many protocols have been proposed. In this chapter, we first classify the routing protocols according to application scenarios, which are classified according to the number of sinks that an underwater acoustic sensor network (UASN) may use, namely singleâsink, multiâsink, and noâsink. We review some typical routing strategies proposed for these application scenarios, such as crossâlayer and reinforcement learning as well as opportunistic routing. Finally, some remaining key issues are highlighted
Bring Me a Good One: Seeking High-potential Startups using Heterogeneous Venture Information Networks
Identifying startups with the highest potential for success is a complex task, necessitating the examination of various information sources, including firm demographics, management team composition, and financial performance. The effectiveness of existing methodologies, such as feature-based and network-topological approaches, is limited for predicting high-potential startups. In response, we propose a novel Venture Graph Neural Network (VenGNN) model, leveraging Heterogeneous Information Networks (HIN) and Graph Neural Networks (GNN) techniques to address the prediction problem. Specifically, we construct a Heterogeneous Venture Information Network (HVIN) using raw business data and deem the prediction a node classification task. Our model integrates theory-guided semantic meta-paths, firm demographics, sampling-based self-attention, and centrality encoding to overcome certain constraints of existing GNNs. Our experimental analysis reveals that VenGNN outperforms state-of-the-art models by 15-20% across a wide range of performance metrics. Our study also includes a comprehensive interpretation analysis to provide investors with an essential understanding for better decision-making
Masked Vision-Language Transformers for Scene Text Recognition
Scene text recognition (STR) enables computers to recognize and read the text
in various real-world scenes. Recent STR models benefit from taking linguistic
information in addition to visual cues into consideration. We propose a novel
Masked Vision-Language Transformers (MVLT) to capture both the explicit and the
implicit linguistic information. Our encoder is a Vision Transformer, and our
decoder is a multi-modal Transformer. MVLT is trained in two stages: in the
first stage, we design a STR-tailored pretraining method based on a masking
strategy; in the second stage, we fine-tune our model and adopt an iterative
correction method to improve the performance. MVLT attains superior results
compared to state-of-the-art STR models on several benchmarks. Our code and
model are available at https://github.com/onealwj/MVLT.Comment: The paper is accepted by the 33rd British Machine Vision Conference
(BMVC 2022
Bring Me a Good One: Seeking High-potential Startups using Heterogeneous Venture Information Networks
A Network Topology Control and Identity Authentication Protocol with Support for Movable Sensor Nodes
It is expected that in the near future wireless sensor network (WSNs) will be more widely used in the mobile environment, in applications such as Autonomous Underwater Vehicles (AUVs) for marine monitoring and mobile robots for environmental investigation. The sensor nodesâ mobility can easily cause changes to the structure of a network topology, and lead to the decline in the amount of transmitted data, excessive energy consumption, and lack of security. To solve these problems, a kind of efficient Topology Control algorithm for node Mobility (TCM) is proposed. In the topology construction stage, an efficient clustering algorithm is adopted, which supports sensor node movement. It can ensure the balance of clustering, and reduce the energy consumption. In the topology maintenance stage, the digital signature authentication based on Error Correction Code (ECC) and the communication mechanism of soft handover are adopted. After verifying the legal identity of the mobile nodes, secure communications can be established, and this can increase the amount of data transmitted. Compared to some existing schemes, the proposed scheme has significant advantages regarding network topology stability, amounts of data transferred, lifetime and safety performance of the network
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