SGEU-Net:用于从高分遥感影像中提取道路的空间分组增强注意力网络

道路提取是现代路网规划的重要组成部分。近来,许多深度学习方法已被应用于该领域。然而,由于车辆以及树木和建筑物阴影的遮挡,在保持连续性的同时准确提取道路区域仍然是一个问题。论文提出了一种新型的道路提取网络-空间分组增强网络(SGEU-Net),由两个部分构成:一个改进的U-Net编码器-解码器网络和空间分组增强(SGE)注意力模块。SGE模块可以明显改善不同语义子特征在组内的空间分布,产生更可观的统计差异,增强语义区域的特征学习。改进的算法在马萨诸塞州道路数据集上进行实验,结果表明,与当前先进算法相比,所提算法提高了从遥感图像中提取道路的效果。

基于空间分组GCN的UAV航拍视频行为识别

人体行为识别(human action recognition,HAR)是从无人机捕获视频中理解行人意图的一项关键技术。但无人机平台算力有限、现有行为识别方法效率较低。提出轻量级的空间分组注意力图卷积网络,降低网络深度,提升效率并保证行为识别精度。为了捕获能够代表全局运动的肢体部位,提出空间分组注意力模型,增强与全局特征相似性高的局部特征。此外,仅靠关节和骨架特征无法有效区分具有相似运动轨迹的行为,构建骨骼角度的高阶特征编码,捕获更能反映细微运动差异的肢体关节间角度的变化,提升特征的表示能力。最后,针对无人机航拍视频的低帧率问题,提出基于帧间差异的线性插帧方案,提升样本信息量。实验结果表明,与现有SOTA方法相比,该方法在UAV-Human数据集上的识别率、参数量、训练耗时、执行耗时都具有更好的性能。

空间分组增强注意力的轻量级人脸表情识别

由于人脸表情特有的复杂性与微妙性,对表情进行高精度识别是一个困难问题。针对轻量级网络在自然环境下对面部表情的特征提取不够充分、泛化能力不足等问题,提出了一种基于空间分组增强注意力的轻量级人脸表情识别方法。在浅层网络设计了并行的深度卷积残差结构,以增强模型对面部表情局部细节的表征能力,并与全局整体特征相融合。在深层网络建立了空间分组增强注意力机制,以提高表情特征分布的稳定性,并强化模型对表情细微变化的判别能力。为了避免模型过拟合,在不大量增加计算复杂度的前提下,对主干网络输出结构进行改进。该方法在公开的七分类数据集RAF-DB、AffectNet-7以及八分类数据集AffectNet-8上的表情识别准确率分别达到了88.33%、63.09%和60.12%,实验结果表明,所提方法在降低网络参数的同时,提高了表情识别准确率,证明了该方法的有效性,具有一定的应用前景。

利用空间分组的CDMA系统多用户检测技术

多用户检测技术可以增加CDMA系统的用户容量。将天线阵列和空间滤波器运用于基站多用户检测之前的信号接收,并通过某一准则将不同方向上的用户分为互相关性很小以至可以忽略的不同相似组,进而忽略不同组的用户之间的多址干扰(MAI),在此基础上再对各组分别进行信息检测,将能大大减小多用户检测的计算量,提高信号处理速度。

基于改进MobileNet V2的多视图三维人脸重建

针对多视图三维人脸重建时,由于图像特征提取能力有限而导致三维人脸模型重建效果不佳的问题,本文提出了一种基于改进MobileNet V2网络的三维人脸重建方法。首先在MobileNet V2网络中引入多路径结构,使不同子路径的特征能够进行交互,从而增强网络的表达能力;然后在通道维度上加入压缩激励(Squeeze and Excitation,SE)模块,在空间维度上加入空间分组增强(Spatial Group-wise Enhance,SGE)模块,从而有效提取人脸形状参数和表情参数;最后使用三维可形变模型(3D Morphable Model,3DMM),并根据形状参数和表情参数完成三维人脸重建。在300W-LP数据集上,与基于卷积神经网络(Convolutional Neural Network,CNN)的重建方法以及基于Visual Geometry Group Batch Normalization(VGG-BN)改进网络的重建方法进行对比实验,实验结果表明平均重建精度分别提升约0.46%和0.31%。

一种改进的真三维R树空间索引方法

利用k-均值算法和覆盖体积与重叠体积之和作为分组的综合指标,改进了现有的三维空间聚簇分组和R树插入算法。实验证明,该算法显著减少了R树兄弟节点之间的重叠现象,而且节点尺寸均匀,有利于海量三维空间数据的高效管理与实时可视化应用。

现实场景典型空间位置关系客体的解码效应

通过探讨典型空间关系客体对中单个客体的视觉工作记忆,考察空间位置关系的解码特征和主动客体记忆优势。结果发现:(1)当客体以符合空间位置关系方式呈现时,记忆更准确;(2)符合空间位置关系条件下单个客体提取反应时更长,上方客体反应时更短,记忆更准确;(3)兼具空间位置关系与动作关系客体对中的主动客体记忆正确率更高。结果表明,现实场景客体空间分组中单个客体提取时存在解码现象和顺序效应,对现实中的上方与主动客体存在加工偏好。

Seasonal variation in species composition and abundance of tintinnids in Shantou coastal water,China

Two cruises were conducted to study the composition and seasonal variation of tintinnids （Protozoa： Ciliata） in Shantou coast water dudng spring and fall. Remarkable seasonal variations in environmental parameters, and tintinnids composition were observed. Tintinnids samples were enumerated and identified from 5 stations. 14 species belonging to 7 genuses of tintinnids were identified, and the dominate species was Leprotintinnus simple in these season. High tintinnids diversity and low abundance occurred in the fall, and on the contrary, low tintinnids diversity and high abundance occurred in the spring. No significant correlation occurred between tintinnids abundance and nutrients. Tintinnids abundance showed negative relationship with salinity （r2=0.63, P 〈 0.05）, maybe this was due to the cold raised water carried sum nutrients rise to the surface water in the fall, rich nutrients and high phytoplankton biomass decrease the importance of tintinnids in the energy flow of aquatic food web.

Distribution and composition of tintinnids ciliates in the northern South China Sea during summer

Tintinnids were enumerated and identified in samples collected from 36 stations between 18°-22°N, 107°-122 °E in the northern South China Sea （NSCS）. 44 species belonging to 24 genera of tintinnids were recorded. The dominant species were He/icostome/la /onga and Tintinnopsis radix. Tintinnids abundance ranged from 0 to 2 200 cell/L, and mean abundance was 221cell/L in the surface water. Tintinnids abundance and species numbers decreased from coast to offshore. Upwelling and Pearl River discharge influenced the distribution of tintinnids by regulating nutrients supply. Maximum abundance （2 200 cell/L） was found in the surface water of A1. Tintinnids abundance showed positive relationship with chlorophyll a （Chl a） concentration, and no significant relationship was found between tintinnids abundance and temperature.

一种新OFDM系统及其信道盲估计性能的研究

提出了一种采用不等长分组新的OFDM系统。采用不等长分组的好处是不需要加循环前缀,就能在发射序列中引入周期平稳性,因此采用子空间算法可实现信道的盲辨识。还对信道盲估计性能进行了分析。

Spatial channel pairing-based maximum ratio combining algorithm for cooperative relay networks

To improve the reliable performance of information transmission in cooperative relay networks, the scheme of the max-rate spatial channel pairing （SCP） based on maximum ratio combining （MRC） is proposed. The scheme includes three steps： channel phase cancellation, MRC, and SCP. Eventually, the solution of the scheme is modeled as convex optimization. The objective function of the optimization problem is to maximize the transmission rate and the optimization variable is the strategy of pairing between the uplink spatial sub-channels of each user and the corresponding downlink spatial ones. The theorem of the arrangement inequalities is adopted to obtain the approximate closed-form solution of the optimal pairing for this convex optimization. Simulation results demonstrate that compared to the existing distributed space-time block coding and coherent combined schemes without SCP, the proposed max-rate SCP plus MRC algorithm achieves appreciable improvements in symbol error rate in medium and high signal-to-noise ratio regimes. The achievable performance gain is due to the use of maxrate SCP.

Diatom distribution as an environmental indicator in surface sediments of the West Philippine Basin

The distribution of diatoms from surface sediments of the West Philippine Basin was analyzed, with 68 species and varieties of diatoms from 26 genera identified. Diatom abundance varied spatially, with the absolute abundance of diatoms ranging from 0 to 3.4× 104 frustules/g. The seven tropical pelagic diatoms were Alveus marinus, Azpeitia africana, Azpeitia nodulifera, Hemidiscus cuneiformis, Hernidiscus cuneiformis var. ventricosus, Roperia tesselata and Rhizosolenia bergonii. The relative abundance of these species was greater than 20%, and their distribution pattern in the sediments was overlaid by the flow of the Kuroshio Current. Ethmodiscus rex was present at 159 stations, formed the most abundant and dominant species in the diatomaceous ooze, and thus referred to as Ethmodiscus ooze. Ethmodiscus rex was also a major contributor to primary production in the region. A principal component analysis was employed to explain the relationship between samples and variations in diatom species from the WPB. Four diatom assemblages were distinguished, representing different oceanographic conditions; their spatial distributions were closely related with the North Equatorial Current and Kuroshio Current patterns in the region. These diatom assemblages can therefore be useful in deciphering late Quaternary palaeoceanographic reconstructions of the West Philippine Basin.

Using GIS Spatial Distribution to Predict Soil Organic Carbon in Subtropical China

Spatial distribution of organic carbon in soils is difficult to estimatebecause of inherent spatial variability and insufficient data. A soil-landscape model for a region,based on 151 samples for parent material and topographic factors, was established using a GISspatial analysis technique and a digital elevation model (DEM) to reveal spatial distributioncharacteristics of soil organic carbon (SOC). Correlations between organic carbon and topographicfactors were analyzed and a regression model was established to predict SOC content. Results forsurface soils (0-20 cm) showed that the average SOC content was 12.8 g kg^(-1), with the SOC contentbetween 6 and 12 g kg^(-1) occupying the largest area and SOC over 24 g kg^(-1) the smallest. Also,soils derived from phyllite were the highest in the SOC content and area, while soils developed onpurple shale the lowest. Although parent material, elevation, and slope exposure were allsignificant topographic variables (P < 0.01), slope exposure had the highest correlation to SOCcontent (r = 0.66). Using a multiple regression model (R^2 = 0.611) and DEM (with a 30 m X 30 mgrid), spatial distribution of SOC could be forecasted.

Schmidt Decomposition of Quaternion Matrix and the Orthonormalization of Vectors in a Generalized Unitary Space

In this paper we derive a practical method of solving simultaneously the problem of Schmidt decomposition of quaternion matrix and the orthonormalization of vectors in a generalized unitary space by using elementary column operations on matrices over the quaternion field.

Spatial Organization Mechanism of Aircraft Manufacturing

Unquestionably,aircraft industry plays an important part in both economy and security of a nation.However,few of articles have dealt with the spatial development of this industry sector.The purpose of this article is to analyze the dynamics of agglomeration and diffusion of aircraft industry.In a historical view,with some spatial analysis methods,this research discusses the characteristics and patterns of aircraft industry's spatial organization and evolution,globally,nationally and regionally respectively.We find out there is a ‘Matthew effect' in aircraft industry of the world,and the spatial evolution of the industry is consistent with the nation's industrialization process.Then,it concludes that the main agglomeration forces consist of capital,talents,technology and cluster's advantages,and the main diffusion forces include comparative advantages,cost and risk sharing,emerging markets,development policy for backward regions and military requirements.All the factors can be divided into market forces making the spatial development of aircraft industry normal and non-market forces making that irregular.In particular,lessons from the USA and France are expected to be conducive to the rise of China's aircraft industry in the future.

A New System of Variational Inclusions with （H,η）-accretive Operators in Banach Spaces

In this paper, we first introduce a new class of generalized accretive operators named （H,η）-accretive in Banach space. By studying the properties of （H,η）-accretive, we extend the concept of resolvent operators associated with m-accretive operators to the new （H,η）-accretive operators. In terms of the new resolvent operator technique, we prove the existence and uniqueness of solutions for this new system of variational inclusions. We also construct a new algorithm for approximating the solution of this system and discuss the convergence of the sequence of iterates generated by the algorithm.

Multiverse Spacetime

A theological train of reasoning is avoided in this paper. The properties of the equal operator presented earlier by Alnobani are given here. A view of the present time is given. As a consequence of the presence of time state, the verses are arranged in couples and every verse including in which we live is a live verse in the same context of human life. This paper interferes with and changes the procedures and philosophy of mathematics itself. Space, mass and time are parts of one whole which is called simply time. The aim of this paper is to make the knowledge of its subject public, so other researchers can contribute to it. The concept of a gate between verses is investigated.

Study on City Residential Area Entrance Intercourse Space

Residential area entrance space is an important part of residential areas, which influences space form and also influences the space composition of residents. Through different feature analyses of entrance space for different influences of residents, it can achieve humanized space design and improve the overall level of residential area.

World Cities and International Organizations: Political Global-city Status of Chinese Cities

In this study, the authors use a political perspective to explore the relative global status of cities in China. Two questions are addressed. Firstly, by using international organizations as the subjects and quantitative analysis of the spatial distribution of their offices, the overall position of Chinese cities in the global distribution of international organizations is estimated. The results show that 22 Chi- nese cities are involved in international political affairs. Beijing, Shanghai and Guangzhou dominate these activities and have high po- litical global-city status. Secondly, through qualitative analysis of Guangzhou City, the authors explore how its status as a center for intemational organizations has been shaped in recent years. The locational decision-making process is analyzed and the factors are demonstrated at both national and city scales. The definition of international organizations as used in this study refers not only to those supranational bodies that have the ability to manage relations across states （such as the European Union）, but also those in- ter-governmental organizations （IGOs）, international non-governmental organizations （INGOs） and diplomatic representatives and delegations that today also manage and regulate relations between and among states.

Solutions and Conditional Lie-Backlund Symmetries of Quasi-linear Diffusion-Reaction Equations

New classes of exact solutions of the quasi-linear diffusion-reaction equations are obtained by seeking for the high-order conditional Lie-Baeklund symmetries of the considered equations. The method used here extends the approaches of derivative-dependent functional separation of variables and the invariant subspace. Behavior to some solutions such as blow-up and quenching is also described.