244 research outputs found
Linear Convergence of Adaptively Iterative Thresholding Algorithms for Compressed Sensing
This paper studies the convergence of the adaptively iterative thresholding
(AIT) algorithm for compressed sensing. We first introduce a generalized
restricted isometry property (gRIP). Then we prove that the AIT algorithm
converges to the original sparse solution at a linear rate under a certain gRIP
condition in the noise free case. While in the noisy case, its convergence rate
is also linear until attaining a certain error bound. Moreover, as by-products,
we also provide some sufficient conditions for the convergence of the AIT
algorithm based on the two well-known properties, i.e., the coherence property
and the restricted isometry property (RIP), respectively. It should be pointed
out that such two properties are special cases of gRIP. The solid improvements
on the theoretical results are demonstrated and compared with the known
results. Finally, we provide a series of simulations to verify the correctness
of the theoretical assertions as well as the effectiveness of the AIT
algorithm.Comment: 15 pages, 5 figure
Graph Partitioning Algorithms and Applications on CyTOF Experiments
Graph partitioning is a fundamental problem in computer science and engineering with diverse applications in fields such as circuit design, network analysis, and data mining [6]. The goal of graph partitioning is to divide a given graph into multiple clusters, with the aim of minimizing certain criteria, such as the number of edges between clusters. Numerous algorithms are available for graph partitioning, ranging from simple heuristics to sophisticated optimization techniques. Due to the NP-hard nature of graph partitioning problems, finding efficient algorithms for large-scale graphs partitioning is crucial. This thesis comprehensively studies existing graph partitioning algorithms, including a recently proposed novel algorithm [1]. The performance of these algorithms is compared in terms of accuracy and timing on various datasets. The accuracy of the partitioning results is compared with the true partitioning groups by using the Normalized Mutual Information (NMI) value and the purity measurement. Additionally, these partitioning algorithms are applied to data from a CyTOF experiment, a significant field in biostatistics. The results demonstrate that the proposed algorithm generally outperforms the spectral partitioning algorithm from k-means in terms of partitioning quality, but it requires more time to converge, resulting in higher computational costs. Overall, the proposed algorithm shows promise for producing improved partitioning results, but further optimization for computational efficiency is needed. This work contributes to the understanding of graph partitioning algorithms and their performance, providing insights for future research in this area.Bachelor of Scienc
Modeling and Applied Research in Sustainable Development
We develop an algebraic polynomial model to measure and compare the sustainability in 4 countries after studying existing sustainable development index systems. The model consists of three facets of indicators: natural resources reserve, environment carrying capacity and social welfare level. We use recursive least-squares method (RLS) to determine the parameters of the fitted model and apply this model to design a sustainable development plan for Tanzania. Considering the country profile and model testing results, the plan comprises of five programs: producing clean water, generating electricity, improving transport conditions, developing tourism industry and advancing medical and health services. Finally we predict the change of each indicator in the next two decades and compare the results under natural state, finding that the sustainability of Tanzania will increase
Afghanistan and Regional Security: Implications for China
[The United States is going to start off the well-publicized withdrawal of coalition
forces from Afghanistan. This will signify a major shift of US strategic designs in
the region: from short-time tactical operation to long-term strategic presence. The
US forces in Afghanistan will likely be further reduced in due time, but the US efforts
for transforming Afghanistan into a strategic stronghold will be enhanced. Such a
shift will undoubtedly bring about a major implication for China, as a neutral and
stable Afghanistan is in its interest. It is thus recommended to make joint efforts
with like-minded countries to prevent Afghanistan from sliding into chaos and thus
jeopardizing China, and to prevent the perpetualization of US strategic presence in
Afghanistan.]
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Federated Knowledge Graph Completion via Latent Embedding Sharing and Tensor Factorization
Knowledge graphs (KGs), which consist of triples, are inherently incomplete
and always require completion procedure to predict missing triples. In
real-world scenarios, KGs are distributed across clients, complicating
completion tasks due to privacy restrictions. Many frameworks have been
proposed to address the issue of federated knowledge graph completion. However,
the existing frameworks, including FedE, FedR, and FEKG, have certain
limitations. = FedE poses a risk of information leakage, FedR's optimization
efficacy diminishes when there is minimal overlap among relations, and FKGE
suffers from computational costs and mode collapse issues. To address these
issues, we propose a novel method, i.e., Federated Latent Embedding Sharing
Tensor factorization (FLEST), which is a novel approach using federated tensor
factorization for KG completion. FLEST decompose the embedding matrix and
enables sharing of latent dictionary embeddings to lower privacy risks.
Empirical results demonstrate FLEST's effectiveness and efficiency, offering a
balanced solution between performance and privacy. FLEST expands the
application of federated tensor factorization in KG completion tasks.Comment: Accepted by ICDM 202
Spatiotemporal Attention Enhances Lidar-Based Robot Navigation in Dynamic Environments
Foresighted robot navigation in dynamic indoor environments with
cost-efficient hardware necessitates the use of a lightweight yet dependable
controller. So inferring the scene dynamics from sensor readings without
explicit object tracking is a pivotal aspect of foresighted navigation among
pedestrians. In this paper, we introduce a spatiotemporal attention pipeline
for enhanced navigation based on 2D lidar sensor readings. This pipeline is
complemented by a novel lidar-state representation that emphasizes dynamic
obstacles over static ones. Subsequently, the attention mechanism enables
selective scene perception across both space and time, resulting in improved
overall navigation performance within dynamic scenarios. We thoroughly
evaluated the approach in different scenarios and simulators, finding good
generalization to unseen environments. The results demonstrate outstanding
performance compared to state-of-the-art methods, thereby enabling the seamless
deployment of the learned controller on a real robot
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