58 research outputs found

    Outage Performance and Optimal Design of MIMO-NOMA Enhanced Small Cell Networks With Imperfect Channel-State Information

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    This paper focuses on boosting the performance of small cell networks (SCNs) by integrating multiple-input multiple-output (MIMO) and non-orthogonal multiple access (NOMA) in consideration of imperfect channel-state information (CSI). The estimation error and the spatial randomness of base stations (BSs) are characterized by using Kronecker model and Poisson point process (PPP), respectively. The outage probabilities of MIMO-NOMA enhanced SCNs are first derived in closed-form by taking into account two grouping policies, including random grouping and distance-based grouping. It is revealed that the average outage probabilities are irrelevant to the intensity of BSs in the interference-limited regime, while the outage performance deteriorates if the intensity is sufficiently low. Besides, as the channel uncertainty lessens, the asymptotic analyses manifest that the target rates must be restricted up to a bound to achieve an arbitrarily low outage probability in the absence of the inter-cell interference.Moreover, highly correlated estimation error ameliorates the outage performance under a low quality of CSI, otherwise it behaves oppositely. Afterwards, the goodput is maximized by choosing appropriate precoding matrix, receiver filters and transmission rates. In the end, the numerical results verify our analysis and corroborate the superiority of our proposed algorithm

    Parity Splitting and Polarized-Illumination Selection of Plasmonic Higher-Order Topological States

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    Topological states, originated from interactions between internal degree of freedoms (like spin and orbital) in each site and crystalline symmetries, offer a new paradigm to manipulate electrons and classical waves. The accessibility of spin degree of freedom has motivated much attention on spin-related topological physics. However, intriguing topological physics related to atomic-orbital parity, another binary degree of freedom, have not been exploited since accessing approaches on atomic orbitals are not well developed. Here, we theoretically discover spectral splitting of atomic-orbital-parity-dependent second-order topological states on a designer-plasmonic Kagome metasurface, and experimentally demonstrate it by exploiting the easy controllability of metaatoms. Unlike previous demonstrations on Hermitian higher-order topological insulators, radiative non-Hermicity of the metasurface enables far-field access into metaatomic-orbital-parity-dependent topological states with polarized illuminations. The atomic-orbital parity degree of freedom may generate more intriguing topological physics by interacting with different crystalline symmetries, and promise applications in polarization-multiplexing topological lasing and quantum emitters.Comment: 19 pages, 4 figure

    Conjuntos excepcionais e alguns problemas de Mahler

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    Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, 2017.Seja f uma função inteira e transcendente. Denotamos por Sf o conjunto de todos os α ∈ ´Q tais que f(α) ∈ ´Q (o conjunto excepcional de f). Nessa dissertação, mostraremos quais subconjuntos de ´Q podem ser o conjunto excepcional de alguma função inteira e transcendente. Além disso, trataremos de dois problemas de Mahler relacionados a propriedades de funções inteiras e transcendentes. Mostraremos que existem funções inteiras e transcendentes que levam um subconjunto dos números de Liouville nele mesmo e daremos uma resposta positiva ao Problema B de Mahler: Problema B: Existe uma função inteira e transcendente f(z) = Σn =0 ∞ a nz n com coeficientes racionais tal que f( ´Q ) ⊆ ´Q e f−1( ´Q ) ⊆ ´Q ? .Let f be an entire transcendental function. We denote by Sf the set of all α ∈ ´Q such that f(α) ∈ ´Q (exceptional set of f). Throughout this dissertation, we will show which subsets of ´Q can be the exceptional set of some entire transcendental function. Moreover, we will deal with two of Mahler’s problems related to properties of entire transcendental functions. We will show that there are entire transcendental functions that map a subset of Liouville numbers in itself and we will give a positive answer for Mahler’s Problem B: Problem B: Is there an entire transcendental function f(z) = Σn =0 ∞ a nz n with rational coefficients such that que f( ´Q ) ⊆ ´Q e f−1( ´Q ) ⊆ ´Q ?

    Students’ Perceptions of Online Learning in the Post-COVID Era: A Focused Case from the Universities of Applied Sciences in China

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    Currently, while most universities around the world have returned to offline teaching, most universities in China are still using online teaching. In the current educational context, Chinese universities switch between online and offline teaching modes at any time depending on the epidemic situation in their city. This paper discusses students’ perceptions of online learning in the post-COVID era in China. Based on the data collected from student questionnaires, the teaching and learning situation in the post-COVID era and student preferences for online learning are discussed. In addition to this, the statistics program JMP was used to perform the data analysis. The correlations among study characteristics, socio-economic factors, organisational and didactic design, and the acceptance and use of online learning are analysed. The results show that students spend more time in university courses in the post-COVID era than in previous academic years. Students prefer to study alone and at individual times that are set by themselves. Study characteristics and the socio-economic situation of the students are not related to the acceptance and usage behaviour of online learning. The organisational and didactic design of online learning is correlated with its acceptance. In the end, the reflection on opportunities for online learning in the post-COVID era is concluded

    Ghost-Free Multi-Exposure Image Fusion Technology Based on the Multi-Scale Block LBP Operator

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    This paper proposes a ghost-free multi-exposure image fusion technique based on the multi-scale block LBP (local binary pattern) operator. The method mainly includes two steps: first, the texture variation, brightness, and spatial consistency weight maps of the image are computed, and then these three image features are used to construct the initial weight map. Finally, the multi-resolution method is used to fuse the images to obtain the resulting image. The main advantage of this technique lies in the step of extracting the details of the source image based on the multi-scale block LBP operator, which is used to preserve the details of the brightest and darkest areas in high dynamic range scenes and preserve the texture features of the source image. Another advantage is that a new LBP operator-based motion detection method is proposed for fusing multi-exposure images in dynamic scenes containing moving objects. In addition, this paper also studies two spatially consistent weight distribution methods and compares and discusses the effects of these two methods on the results of dynamic image fusion. Through a large number of experimental comparisons, the superiority and feasibility of this method are proved

    Reflection about popular culture in the context of visual communication

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    Conference Name:2011 International Conference on Material Science and Information Technology, MSIT2011. Conference Address: Singapore, Singapore. Time:September 16, 2011 - September 18, 2011.Singapore Institute of ElectronicsTaking popular culture in the context of visual communication as its research objectives, this article mainly analyses the visual hegemony of popular culture and the plight of paper-reading from the perspective of a reflective angle of view under the visual shift of popular culture. It reveals that the visual shift of popular culture causes the plight of paper-reading and has adverse affect on human thinking and traditional cultural heritage. Meanwhile, human are always be 'monitored' and the privacy can not be protected. And the willing to be 'monitored' and adopt privacy becomes the means for individual or group to get benefit. 漏 (2012) Trans Tech Publications, Switzerland

    Ghost-Free Multi-Exposure Image Fusion Technology Based on the Multi-Scale Block LBP Operator

    No full text
    This paper proposes a ghost-free multi-exposure image fusion technique based on the multi-scale block LBP (local binary pattern) operator. The method mainly includes two steps: first, the texture variation, brightness, and spatial consistency weight maps of the image are computed, and then these three image features are used to construct the initial weight map. Finally, the multi-resolution method is used to fuse the images to obtain the resulting image. The main advantage of this technique lies in the step of extracting the details of the source image based on the multi-scale block LBP operator, which is used to preserve the details of the brightest and darkest areas in high dynamic range scenes and preserve the texture features of the source image. Another advantage is that a new LBP operator-based motion detection method is proposed for fusing multi-exposure images in dynamic scenes containing moving objects. In addition, this paper also studies two spatially consistent weight distribution methods and compares and discusses the effects of these two methods on the results of dynamic image fusion. Through a large number of experimental comparisons, the superiority and feasibility of this method are proved

    New insights into the role of immunity and inflammation in diabetic kidney disease in the omics era

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    Diabetic kidney disease (DKD) is becoming the leading cause of chronic kidney disease, especially in the industrialized world. Despite mounting evidence has demonstrated that immunity and inflammation are highly involved in the pathogenesis and progression of DKD, the underlying mechanisms remain incompletely understood. Substantial molecules, signaling pathways, and cell types participate in DKD inflammation, by integrating into a complex regulatory network. Most of the studies have focused on individual components, without presenting their importance in the global or system-based processes, which largely hinders clinical translation. Besides, conventional technologies failed to monitor the different behaviors of resident renal cells and immune cells, making it difficult to understand their contributions to inflammation in DKD. Recently, the advancement of omics technologies including genomics, epigenomics, transcriptomics, proteomics, and metabolomics has revolutionized biomedical research, which allows an unbiased global analysis of changes in DNA, RNA, proteins, and metabolites in disease settings, even at single-cell and spatial resolutions. They help us to identify critical regulators of inflammation processes and provide an overview of cell heterogeneity in DKD. This review aims to summarize the application of multiple omics in the field of DKD and emphasize the latest evidence on the interplay of inflammation and DKD revealed by these technologies, which will provide new insights into the role of inflammation in the pathogenesis of DKD and lead to the development of novel therapeutic approaches and diagnostic biomarkers

    The Integration of New-Type Urbanization and Rural Revitalization Strategies in China: Origin, Reality and Future Trends

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    New-type urbanization and rural revitalization have gradually become national strategies, and are an objective requirement for China to be able to enter into a new era of socialism with Chinese characteristics and also an inevitable result of the integration of new-type urbanization and rural development in the new stage. This paper reviews the classic theories and cognition of the research on urban–rural relations at home and abroad, and outlines the stage evolution characteristics of urban–rural relations in China. It is believed that urban-biased urbanization has widened the development gap between urban and rural areas since reform and opening up. Under the guidance of the two strategies of new-type urbanization and rural revitalization, urban and rural areas have transitioned from “one-way flow” to “bilateral interaction”, and from “urban bias” to “urban–rural integration”. This paper puts forward a research framework and scientific issues regarding the integration of new-type urbanization and rural revitalization from multidisciplinary perspectives. The integration of these two major strategies will contribute to a new situation of the coordinated and high-quality development of urban and rural areas in the new era
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