Ionic liquids (ILs) are promising eco-friendly solvents for carbon dioxide (CO2) dissolution and capture. Utilizing deep neural network modeling to accelerate the design and …
Physics–Informed Neural Networks (PINNs) have demonstrated efficacy in solving both forward and inverse problems for nonlinear partial differential equations (PDEs). However, they …
In industrial manufacturing, the measurability of surface defects directly impacts the accuracy of quality assessment and the effectiveness of process control. While object …
This study evaluates the applicability of the physics-informed operator network (PIO-Net) for reconstructing subsurface density anomalies (SDAs) based on sea surface density. …
Hyperbolic conservation laws play a critical role in various fields, including aerodynamics, physics, and oceanography. However, traditional physics-informed neural networks …
传统的胶囊网络架构是基于动态路由机制实现的，需要大量迭代和向量计算来更新权值系数，并且胶囊之间不存在信息共享，导致信息冗余。针对这一缺陷，本工作提出了一种基于融合深度胶囊网络的多声音事件检测模型，在门控卷积和3D卷积下通过动态路由减少了特征重叠导致的信息冗余，并且对原始特征进行编码，将其用于特征信息补充，提高了训练次数模型的速度和准确性。本工作使用 …
The concentration characteristics of SO2, NO2, O3, and CO in the marine atmosphere are of great significance for understanding air-sea interactions and regional atmospheric …
Accurate estimation of high-resolution thermocline depth is important for investigating ocean processes and climate variability on multiple scales. Due to the sparse coverage and …
In this article, the problem of event-triggered (ET) adaptive finite-time tracking control is investigated for full-state constrained stochastic nonlinear systems with unknown …
This paper proposes an innovative adaptive event-triggered control strategy for a class of state time-delays nonlinear multi-agent systems (MASs) with full state constraints. …
单桩是海上风电工程中最常用的基础形式，桩-土相互作用关系是桩基设计中需要重点考虑的因素。现有设计规范中的推荐公式适用于砂土和黏土这两种极端土质。然而，在全球范围内广泛分布着兼具砂土和黏土特性（非零内聚力和非零摩擦角）的过渡土质——粉土。若仅考虑单一土质特性，可能会造成桩基设计的不经济性和不可靠性。此外，传统的p-y模型主要针对单一长径比的桩基，而对于长径比动 …
Multi-object tracking (MOT) is a pivotal research area in computer vision. Effectively tracking objects in scenarios with frequent occlusions and crowded scenes has become a key …
The Ekman equation is a fundamental model for describing the wind stress response in the ocean's upper layer,with its key parameters—the vertical eddy viscosity coefficient (VEVC) …
Accurate disparity estimation in diverse and complex scenes remains a significant challenge in stereo matching, requiring precise geometric perception and robust generalization. …
The rapid and stable monitoring of CO2 emissions from point sources in localized regions remains a key challenge in energy conservation and emission reduction efforts. To address …
An adaptive tracking control scheme based on a multi-dimensional Taylor network(MTN) is proposed for nonlinear systems with multiple sensor faults and actuator saturation. This …
Deep operator networks (DeepONets), as a powerful tool to approximate nonlinear mappings between different function spaces, have gained significant attention recently for …
This paper investigates the adaptive tracking control problem for nonlinear multi-agent systems operating under simultaneous input saturation and output performance constraints. To …
Sound event detection (SED) is a challenging task where ambient sound events are detected from a given audio signal, which includes categorizing the events and estimating their …
Ozone (O3) is a major atmospheric pollutant, and accurate prediction of its concentrations remains challenging due to its complex nonlinear relationships with precursor compounds. …
Three extreme cold events occurred in eastern Asia in January 2016, January 2021, and December 2023. As important factors in atmospheric circulation anomalies, the Blocking High …
Recently, the utilization of pre-trained models to transfer knowledge to downstream tasks has become an increasing trend. In this paper, we present an effective sound event …
In this paper, we present a new scheme to design an adaptive neural backstepping tracking controller for a class of stochastic nonlinear systems with unknown input constraints …
This paper presents a practical predefined time control approach for nonlinear multi-agent systems with input saturation. A novel predefined time command filter, constructed using …
Tropical cyclones (TCs) in the western North Pacific (WNP) can modulate the intensity of ENSO by weakening the Walker circulation and exciting or enhancing the eastward oceanic …
Accurate sea surface temperature (SST) prediction is vital for disaster prevention, ocean circulation, and climate change. Traditional SST prediction methods, predominantly reliant …
This paper considers the event-triggered adaptive fault-tolerant control (FTC) problem fora class of stochastic nonlinear systems suffering from finite number of actuator failures …
Variations in ocean mixed layer depth (MLD) show a significant impact on energy balance in the global climate systems and marine ecosystems. So far, the accuracy of modeling MLD, …
The Kuroshio Current (KC) has witnessed rapid surface warming during the past half-century, impacting the marine ecosystems in surrounding regions. However, the vertical structure …
The recent success of emission reduction policies in China has significantly lowered sulfur dioxide (SO2) levels. However, accurately forecasting these concentrations remains …
Increased ocean heat transport (OHT) to the Arctic Ocean from the Atlantic and Pacific oceans contributes to Arctic Ocean warming and sea ice decline in a warming climate, …
Marine heatwaves (MHWs) are extreme coherent ocean temperature events that can have devastating impacts on marine ecosystems and socio-economies. This study assesses the prediction …
This study explored the observation strategy and effectiveness of synoptic-scale adaptive observations for improving sea fog prediction in coastal regions around the Bohai Sea …
The Arctic Ocean’s Beaufort Gyre, the largest Arctic freshwater reservoir, plays a crucial role for climate and marine ecosystems. Understanding how it changes in a warming climate …
This paper studies the finite-time control problem of a class of switched non-linear systems under time-varying state constraints and proposes an adaptive finite-time controller …
Timely and accurate representation of sea surface dynamic fields is crucial for oil spill drift prediction. Numerically forecasted sea surface dynamic fields are available in a …
This paper proposes a novel event‐triggered adaptive asymptotic tracking control (ATC) method for stochastic non‐linear systems with unknown hysteresis. Firstly, in order to reduce …
为了探究全球变暖对斜压不稳定的影响，本研究采用1°×1°的温度、盐度和流场格点数据，对1993～2022年南太平洋热带-副热带海区(south Pacific tropical-subtropical,SPTS)表层强化的Charney型斜压不稳定的长期变化趋势及其机制进行了分析。发现南太平洋热带区(south Pacific tropical,SPT)斜压 …
For the nonlinear systems with input delay, an adaptive fixed-time tracking control strategy based on multi-dimensional Taylor network (MTN) is proposed for the first time. First, …
Marine heatwave(MHW) events refer to periods of significantly elevated sea surface temperatures(SST), persisting from days to months, with significant impacts on marine ecosystems, …
风应力拖曳系数是风暴潮模型中的重要参数之一。本工作基于二维的风暴潮数值模型和伴随同化模型，利用数据同化方法反演出了空间分布形式的风应力拖曳系数。研究了空间分布形式的风应力拖曳系数和三种经验公式的风应力拖曳系数对渤、黄、东海海域内7303号台风发生期间的风暴潮水位的影响。结果表明，与风应力拖曳系数经验公式计算的风暴潮水位相比，利用空间分布形式的风应力拖曳系数计 …
The Arctic Ocean’s Eurasian Basin underwent notable atlantification during the 2010s, characterized by warming of the Atlantic Water layer and increased upper ocean salinity. …
Chinese poetry has been a favorite literary genre for thousands of years. Chinese ancient poetry is still being read and practiced, and many famous ancient Chinese poets are …
This paper presents a referential adaptive asymptotic tracking control scheme for nonlinear multi-input and multi-output (MIMO) systems with time-varying full-state constraints and …
Marine heatwaves (MHWs) and total heat exposures (THEs), extreme warming events occurring across the global oceans, seriously threaten marine ecosystems and coastal communities as …
We present a hollow cylindrical three-dimensional nonlinear photonic crystal for annular beam shaping. By inducing a modification with the near-infrared femtosecond laser inside …
Diamond, known for its exceptional thermal, electrical, and mechanical properties, is widely used in precision machining tools, MEMS, and electronic devices. However, because of …
For nonlinear systems with asymmetric input saturation, an adaptive fixed-time control strategy via multidimensional Taylor network (MTN) is proposed to effectively solve the …
Estimating the ocean’s subsurface thermohaline information from satellite measurements is essential for understanding ocean dynamics and the El Niño phenomenon. This paper proposes …
For the tracking control problem of a class of nonlinear systems with input saturation constraint and time-varying delay, an adaptive tracking control scheme based on …
An extreme cold event outbreaks in Eastern China (EC) in December 16-22, 2023. Its maximum intensity (-8.30 degrees C) and duration (7 days) are in the second place in December …
The earliest Asian summer monsoon onset (SMO) occurs in the Bay of Bengal (BoB), heralding the coming of the rainy season. In late April or early May, the strong sea surface …
As a frequently-observed phenomenon in the northern South China Sea (nSCS),subsurface chlorophyll maximum (SCM) evolution from summer to winter remains unclear,neither the …
Digital video watermark is widely used to protect copyright and content authentication. DWT-SVD based method, i.e., discrete wavelet transform (DWT) and singular value …
Content-based image retrieval is an active area of research where image content is used to guide the search of relevant images from a dataset. Given a query image, the images in …
In this paper, an adaptive prescribed performance tracking control(PPTC) problem of uncertain nonlinear systems with unknown hysteresis input is investigated. For the purpose of …
Automatic modulation recognition (AMR) technology enables receivers to automatically recognize the modulation type of the received signal for correct demodulation of the received …
This paper introduces a distributed adaptive fault-tolerant control scheme for nonlinear multi- agent systems afflicted by actuator failures. The proposed scheme ensures that the …
In December 2022, the United States (US) experienced an extreme cold event. Its duration was 5 days, and it ranked third in intensity (-9.16 degrees C) during the period from 1979 …
Grid resolution and assimilation window size play significant roles in storm surge models. In the Bohai Sea, Yellow Sea, and East China Sea, the influence of grid resolution and …
Estimating ocean subsurface thermohaline information from satellite data is vital for understanding ocean dynamics and El Niño. This paper presents a double-output Residual Neural …
In this article, the problem of adaptive finite-time tracking control for a class of nonlinear systems subject to backlash-like input hysteresis and multiple objective constraints …
通过将超大型浮式结构物(a very large floating structure,简称VLFS)模拟为黏弹性薄板，本工作对VLFS的非线性水弹性响应进行了解析研究。运用同伦分析方法(the homotopy analysis method,简称HAM),计算出速度势和板挠度的近似迭代解，并根据计算结果着重探究了几个重要的物理参数对黏弹性板形变的影响。结 …
Ocean waves are a critical component of the Earth system, yet directly coupling wave models in climate simulations is computationally expensive. We introduce GWSM4C, a Global Wave …
新背景下给教学带来极大挑战，而互联网教育理念下的移动教学却给师生带来无限生机。当今时代，网络技术迅猛发展，传统的课件媒体、板书教学与基于移动智能终端 APP 的现代化教学深度融合，逐渐形成了移动教学模式。移动教学模式不仅以移动智能终端 APP 和网络电脑终端为线上学习平台，还结合多媒体、课件等进行线下课堂教学，体现了互动、交互式的课堂环境，助推了评价方式由结 …
目前主要从时空角度出发对海洋三维温度场进行预测，却忽略了相邻位置的海温相关关系。为弥补这一不足，构建一种融合了自注意力记忆模块与卷积式长短时记忆神经网络（ConvLSTM）模型的SA-ConvLSTM三维温度场预测模型，不仅可以从历史三维温度场中提取海温时空特征，还能获取并记忆相邻点位置信息，从而实现对三维温度场时空变化的把握。实验结果表明：相较于 …
Predefined-time control has experienced substantial advancements in recent years. Nevertheless, the current technology has not achieved widespread adoption in nonlinear multi-agent …
伴随全球变暖和有卫星观测记录以来北极秋季海冰密集度的下降，近几年，东亚地区极端降温事件频繁发生。基于北极涛动指数、北极海冰密集度及温度、位势高度和风场等大气环流数据，研究2021年1月和2024年1月我国极端寒潮的时空变化特征及其原因机制。2021年1月1日至9日，2024年1月17日至24日，我国东部地区（115°00′～120°00′E, …
In marine ecology research, it is crucial to accurately identify the marine mammal species active in the target area during the current season, which helps researchers understand …
该文基于多源辐射观测资料，采用随机森林（RF）算法、季节差分自回归移动平均（SARIMA）模型及特征重要性等方法，对山东省济南市太阳辐射长期变化趋势和影响因素进行综合分析。结果显示：RF模型拟合月太阳辐射效果较好，决定系数和平均绝对百分比误差分别为0.92和9%，优于SARIMA模型；济南市及周边地区月太阳辐射1980—2020年经历“变暗”到“变亮”的过程 …
Insufficient studies in characterizing vertical structure of Chlorophyll-a (Chl-a) in the ocean critically limit better understanding about marine ecosystem based on global climate …
In this paper, an event-triggered adaptive tracking control strategy is proposed for strict-feedback stochastic nonlinear systems with predetermined finite-time performance. …
This article investigates the problem of adaptive tracking control for stochastic nonlinear systems with deferred state constraints. The novel unified universal barrier function …
Reliable long-term wave data are significant for understanding changes and variability of ocean waves, which has important implications for coastal engineering, land erosion, and …
We experimentally demonstrate the highly-efficient nonlocal erasing and writing of ferroelectric domains using a femtosecond laser in lithium niobate. Based on the induction of a …
In this paper, the control issue of adaptive fault-tolerant is studied for a class of stochastic nonlinear systems with multiple faults and full state constraints, with multiple …
海表面温度(sea surface temperature, SST)是影响海洋和气候变化的重要因素之一，准确预测SST的变化对于海洋生态环境、气象和航行等至关重要。传统的SST预测方法通常依赖于数值模式，但是其计算成本较高。该文基于深度学习模型(3D U-Net)，将SST、海表面高度异常(sea surface height anomalies, …
针对提升利用卫星观测海面信息重构三维温盐场精度的问题,本文提出了一种基于多尺度耦合正交分解的三维温盐场重构方法。该方法利用多尺度耦合正交分解对历史温盐剖面进行从大尺度到小尺度的迭代分解,以分层提取不同尺度三维温盐场的特征信息,然后分别建立海洋表面卫星观测与不同尺度的三维温盐场特征信息的重构模型,从而达到三维温盐场重构的目的。本文分别利用多尺度耦合正交分解法与 …
Soil carbon content prediction based on hyperspectral images can achieve large-scale spatial measurement, which has the advantages of wide coverage and fast information collection, …
Sound event detection (SED) is a widely studied field that has achieved considerable success. The dynamic routing mechanism of capsule networks has been used for SED, but its …
WeexperimentallyextendthenonlinearGaussiantofat-topbeamshapingfromonetotwodimensionsthroughathree-dimensionalnonlinearphotoniccrystal.Employinganear-infraredfemtosecondlaser,weindu …
Finer resolution is one of the development trends in ocean surface waves simulation and forecasting. However, high-resolution numerical models for ocean surface waves have led to …
It is the first report about fault-tolerant-based prescribed performance control of switched nonlinear systems under multiple faults. The concerned faults include not only external …
In this paper, the tracking control problem of the state constrained stochastic nonlinear systems with unknown control direction is studied, and a novel adaptive prescribed …
To improve Arctic sea ice simulations by the First Institute of Oceanography–Earth System Model (FIO–ESM), the model version has been updated from FIO–ESM v2.0 to FIO–ESM v2.1 by …
Exploring methods to reconstruct the ocean interior from surface data is a crucial focus in the study of ocean processes and phenomena due to the shortage of subsurface and …
This paper investigates the adaptive tracking control problem of a class of nonlinear systems with intermittent actuator faults and prescribed performance. In the backstepping …
The coupling between wind stress perturbations and sea surface temperature(SST)perturbations induced by tropical instability waves(TIWs) in the Pacific Ocean has been revealed …
Sketch-based image retrieval is an important research topic in the field of image processing. Hand-drawn sketches consist only of contour lines, and lack detailed information such …
For a class of stochastic nonlinear systems, this paper proposes a novel event-triggered adaptive control scheme by means of multi-dimensional Taylor network (MTN) approach for the …
As a ubiquitous motion phenomenon in the ocean, mesoscale eddies play a key role in the transport and distribution of global heat, salinity, energy and marine biochemical …
Mesoscale eddies are swirling motions with a radius ranging from several tens to a hundred of kilometers. The mesoscale eddies can cause strong vertical displacement of isopycnals, …
We investigate the problem of oil spill timely backtracking. Most existing methods for backtracking oil spills rely heavily on historical wind fields. However, during the crucial …
Accurately and effectively estimating of the barrier layer thickness (BLT) is essential for the research of ocean thermodynamics, ocean dynamics, and air-sea interaction. …
Accurately and effectively estimating of the barrier layer thickness (BLT) is essential for the research of ocean thermodynamics, ocean dynamics, and air-sea interaction. …
As important atmospheric circulation patterns in Northern Hemisphere(NH), the North Atlantic Oscillation(NAO) and the Western Pacific teleconnection(WP) affect the winter climate …
In this paper, the adaptive fault-tolerant control (FTC) problem is addressed for the stochastic nonlinear systems with multiple faults. The multiple faults, including the actuator …
Steady-state hydroelastic waves generated by a moving load with a uniform current are investigated analytically in the framework of nonlinear potential theory. Considering the load …
海洋沉积物粒度研究对解析人类活动的环境影响具有重要意义，为提升沉积物粒度光谱分类精度，提出一种主成分分析（PCA）与连续投影算法（SPA）融合的特征提取方法（FOPAS），综合两种算法优势，丰富特征波长信息，剔除无关干扰的同时最大限度保留有效特征。以青岛东大洋村潮间带32份表层沉积物为研究对象，按0.3~0.2 mm、0.2~0.1 mm、0.1~0.075 …
北斗一代和北斗二代短报文每次通信数据长度只有78个字节,每次通信后间隔60秒或者300秒才能进行下一次通信,远远满足不了海洋观测实时通信的需求。设计了一套基于北斗短报文的海洋观测实时通信系统,北斗多卡机作为数据发送端,采用哈夫曼压缩算法将观测数据压缩后分成多个数据包,通过多个北斗卡分别发送,岸站接收系统接收到分包的数据后,将接收的数据包解压缩并整合成完整的观 …
针对飞行器纵向模型的不确定性参数和随机干扰，研究了一类飞行器航迹倾角的自适应跟踪控制问题。 在控制器设计过程中，将多维泰勒网(multidimensional Taylor network, MTN)的逼近特性和自适应backstepping方法相结合， 利用MTN网络逼近未知光滑非线性函数，提出了一种新的自适应MTN控制方法。通过Lyapunov稳定性理论 …
In this paper, the problem of sampled-data adaptive tracking control for a class of switched nonlinear systems with prescribed performance is considered. In order to guarantee the …
The development of high-resolution, fully coupled, regional Earth system model systems is important for improving our understanding of climate variability, future projections, and …
El Niño and the Southern Oscillation (ENSO) is the most influential interannual climate variability on Earth. The tendency of the mature phase of ENSO, characterized by the …
This paper focuses on an adaptive decentralized prescribed performance control problem for a class of large-scale stochastic nonlinear systems with asymmetric input saturation and …
强国必须强军，军强才能国安。在国际形势复杂多变的背景下，以习近平同志为核心的党中央提出了建设一支听党指挥、能打胜仗、作风优良的人民军队，把人民军队建设成为世界一流军队的强军目标。新时代强军目标的理论内涵丰富，听党指挥是强军之魂，能打胜仗是强军之要，作风优良是强军之基，这充分体现了人民军队建设的现代化导向、实践性要求和全局性战略。坚决贯彻党在新时代的强军目标， …
The sampling interval for reliably monitoring interannual variability of the Kuroshio transport was studied using satellite altimeter data and outputs from HYbrid Coordinate Ocean …
In this article, the problem of event-triggered adaptive asymptotic tracking control (ATC) for stochastic nonlinear systems with unknown control directions (UCDs) and full state …
This paper is concerned with the tracking control for a class of switched nonlinear systems subject to prescribed performance. Firstly, a barrier function and a normalized function …
Curved plasma channels have been proposed to guide intense lasers for various applications, such as x-ray laser emission, compact synchrotron radiation, and multistage laser …
本文利用东京台风中心(Tokyo-Typhoon Center)发布的热带气旋(Tropical cyclone, TC) best-tracks资料，统计了1979—2019年经过黑潮关键区热带气旋的强度变化特征，并进一步分析了其中的物理机制。统计结果显示，黑潮对不同强度TC的加热效果不同，整体而言，TC外缘靠近黑潮关键区至TC中心进入关键区阶段，TC风速 …
通过使用天气研究与预报(Weather Research and Forecasting, WRF)模式对热带气旋(Tropical Cyclone, TC)个例“派比安”(1807)进行了一组数值试验，分析了东海黑潮暖舌对“派比安”强度的影响。研究结果表明，东海黑潮暖舌高海面温度(以下简称“海温”)导致TC区域内海气界面热通量显著增加，并造成TC边界层不稳 …
Abstract. Arctic Ocean simulations in 19 global ocean–sea-ice models participating in the Ocean Model Intercomparison Project (OMIP) of the Coupled Model Intercomparison Project …
The finite-time control of switched nonlinear systems subject to multiple objective constraints is investigated in this article. Firstly, with the aim of dealing with the major …
A recent study by Liu et al.(2020) suggested that due to the saturation of equatorially trapped planetary waves with different dynamical types, temporal periods, meridional and …
By virtue of the rapid development of ocean observation technologies, tens of petabytes of data archives have been recorded, among which, the largest portion are those derived from …
An adaptive non-intrusive multi-fidelity reduced basis method for parame-terized partial differential equations is developed. Based on snapshots with differentfidelity, the method …
海洋次表层的热力结构对于海洋环流和全球气候变化具有重要的意义。提出一种新的融合高斯混合模型(gaussion mixture model, GMM)和 轻量级梯度提升机(light gradient boosting machine, LightGBM)算法的海洋次表层温度(ocean subsurface temperature, OST)反演 模型，利用 …
Offshore marine engineering, offshore aquaculture, and offshore environmental protection require periodic offshore surveys. At present, the main means of offshore marine surveys …
Climate change in the Arctic has substantial impacts on human life and ecosystems both within and beyond the Arctic. Our analysis of CMIP6 simulations shows that some climate …
Nitrogen dioxide (NO2) is an important precursor of atmospheric aerosol. Forecasting urban NO2 concentration is vital for effective control of air pollution. This paper proposes a …
As a fundamental nutrient for marine biogeochemical processes, the magnitude and spatial distribution of nitrate concentrations are insufficiently measured in the interior ocean. …
利用1961—2016年山东省济南市太阳年总辐射量观测数据，通过模型识别和统计检验，对比分析时间序列模型AR(5)和ARIMA((1,2,4),1,0)的拟合结果。残差检验结果表明，疏系数模型ARIMA ((1,2,4),1,0)可用于预测地表太阳年总辐射量，预测结果显示2017—2025年济南市地表太阳辐射的年际变化整体呈增长趋势。对比多元线性回归模型结果 …
In this article, adaptive tracking control for a class of switched stochastic nonlinear systems subject to unknown dead-zone input using multi-dimensional Taylor network (MTN) is …
We experimentally demonstrate to drive domain growth in lithium niobate crystal by using a focused infrared femtosecond laser without relative displacement or any additional …
Richards’ equation is a classical differential equation describing water transport in unsaturated porous media, in which the moisture content and the soil matrix depend on the …
Nowadays, one of the most common approaches for video watermarking is to use singular value decomposition in the discrete wavelet transform domain. In our prior work, we formulated …
Ocean wave climate, including wind waves and swells, is essential to human marine activities and global or regional climate systems, and is highly related to harnessing wave energy …
The tendency of El Niño/Southern Oscillation (ENSO) events to peak during boreal winter is known as ENSO phase-locking, whose accurate simulation is essential for ENSO prediction. …
This paper introduces a simple but powerful segmentation algorithm for 3D meshes. Our algorithm consists of two stages: over-segmentation and region fusion. In the first stage, …
In the storm surge model, the wind drag coefficient C-d is a critical parameter that has a great influence on the forecast of the storm surge level. In the present study, the …
Polyphonic sound event detection aims to detect the types of sound events that occur in given audio clips, and their onset and offset times, in which multiple sound events may …
With the rapid marine economic development, the problem of the marine ecological environment has become progressively prominent. Mariculture monitoring plays an essential role in …
In underwater acoustic communications, a hydrophone array is often used to receive the underwater acoustic signals to improve the gain of the received signal. The direction of …
Weexperimentallydemonstratetheuseofafemtosecondlaser-inducedthermoelectricfieldtomanipulateremotely—notonlyatthefocalspot—theinversionandgrowthofferroelectricdomaininlithiumniobate. …
Characterization of nonlocality is an open problem in physics and engineering. This paper conducts a detailed investigation on two nonlocal models, namely, the fractional …
声音事件检测是目前计算机听觉领域中的重要问题，而多声音事件检测是其中一个极具挑战性的研究热点。基于最新提出的非迭代的自注意力路由方法和胶囊网络，本文提出了一种基于自注意力路由的多路径胶囊网络模型，将其用于多声音事件检测。由于自注意力路由方法是非迭代且高度并行的，大大加快了模型的训练速度；多路径基础胶囊层使用不同大小的非对称卷积核，不仅使模型能获得不同分辨率的 …
Monitoring the spatiotemporal iability of nutrient concentrations in shelf seas is important for understanding marine primary productivity and ecological problems. However, long …
自然资源部第一海洋研究所地球系统模式FIO-ESM是自主研发的、以耦合海浪模式为特色的地球系统模式，包括物理气候模式和全球碳循环模式。该模式从第一代版本FIO-ESM v1.0发展到第二代版本FIO-ESM v2.0，其物理气候模式和全球碳循环模式都取得了改进与提升。FIO-ESM v2.0全球碳循环模式的海洋碳循环模式由v1.0的营养盐驱动模型升级为 …
In this article, the issues of asymmetric input saturation and asymmetric time-varying state constraints are integrated into nonlinear systems for the first time, and a new …
For large-scale switched nonlinear systems subject to asymmetric input saturation and output hysteresis, an adaptive control strategy is put forward by using a novel neural …
For the large-scale nonlinear systems subject to dynamic uncertainties, an adaptive multi-dimensional Taylor network (MTN)-based decentralized control strategy is proposed, which …
In this article, an adaptive multi-dimensional Taylor network (MTN) control approach is developed for nonlinear systems subject to input saturation and full state time-ying …
As a keystone instrument on the Fengyun-3C (FY-3C) satellite, the medium resolution spectral imager (MERSI) provides global coverage of top-of-atmosphere radiances for a broad …
In this paper,the stochastic nonlinear systems with full state constraints and dead-zone input are considered in the same framework for the first time,and a new adaptive controller …
Aiming at switched nonlinear systems subject to input delay and saturation,a novel adaptive control strategy is proposed.Firstly,a compensation system is designed,which solves the …
It is a huge challenge for the receiver to correctly identify the modulation types due to the complex underwater channel environment and severe noise interference, while real-time …
Arctic near-surface air temperature warms much faster than the global average, a phenomenon known as Arctic Amplification. The change of the underlying Arctic Ocean could influence …
The effective estimation of mixed-layer depth (MLD) plays a significant role in the study of ocean dynamics and global climate change. However, the methods of estimating MLD still …
Reanalysis wind fields are obtained by correcting the numerically forecasted wind fields based on observation data (i.e., either remote sensing or in-situ observations, or both). …
The effective estimation of mixed-layer depth (MLD) plays a significant role in the study of ocean dynamics and global climate change. However, the methods of estimating MLD still …
提出了一种基于深度卷积神经网络的海洋多目标涡旋检测方法。首先利用改进的密集卷积精确提取海洋涡旋特征，并使用跨层融合技术提高特征的利用率，来充分捕捉边缘信息；然后结合转置卷积和跳过连接构建上采样路径得到检测结果，以获得更高的检测准确率；最后在CMEMS(哥白尼海洋环境监测服务中心)发布的公开数据集上对本工作提出的方法进行了对比实验，实验结果表明：与 …
The Southern Ocean, characterized by strong westerly winds and a rough sea state, exhibits the most pronounced sea spray effects. Sea spray ejected by ocean surface waves enhances …
In this paper, the full state constraints and input delay of stochastic nonlinear systems are studied. A new adaptive control algorithm is proposed using backstepping approach and …
Thanks to attractive properties, such as defect tolerance, broad bandgap tunability, high quantum yields, and large absorption coefficient, perovskites have emerged as a star …
This paper investigates the adaptive decentralized control problem for a class of large-scale nonlinear systems with finite-time output constraints. In order to ensure that the …
This paper serves as an introduction to the Deep-Sea Research II special issue entitled an ocean perspective on CMIP6 model evaluations, which reported the progress of CMIP6 …
Accurately estimating the ocean's interior structures using sea surface data is of vital importance for understanding the complexities of dynamic ocean processes. In this study, we …
基于北极海冰密集度、海冰范围、大气环流和海温数据，研究了1982—2001年与2002—2021年两阶段各20 a间北极秋季海冰的时空变化特征及其原因。结果表明，近20 a(2002—2021年）北极海冰密集度的下降中心由过去（1982—2001年）的楚科奇海及白令海峡一带，转移至亚欧大陆海岸的巴伦支海附近，且海冰范围每10 a减少量由0.44×10~ 6 …
For switched nonlinear systems with output hysteresis, by working on multi-dimensional Taylor network (MTN), an adaptive control strategy is put forward, which can effectively …
潮滩沉积物含水量的时空变化会直接影响生源要素含量，实时、准确、快速监测其含水量对潮滩研究与资源开发具有重要意义。本研究采集青岛东大洋村潮间带115份沉积物样品，测定新鲜、风干4周、风干8周样品的可见近红外光谱与含水量，分别采用db10和sym6小波基对原始光谱进行小波变换，结合偏最小二乘回归建立潮滩沉积物含水量预测模型。通过10阶小波变换获取光谱的低频信息 …
Fine particle (PM2.5) mass concentration and relative humidity (RH) are the primary factors influencing atmospheric visibility. There are some studies focused on the complex, …
In a model plankton ecosystem containing phytoplankton and zooplankton, the later usually avoids toxic phytoplankton and prefers nontoxic species by modulating its grazing rate. …
For the tracking control problem of a class of switched nonlinear systems with input delay, this article proposes an adaptive tracking control scheme based on multi-dimensional …
In this article, the problem of adaptive multi-dimensional Taylor network control for strict-feedback nonlinear stochastic systems with time-delay is investigated. To overcome the …
For the tracking control problem of a class of switched nonlinear systems with input delay, this article proposes an adaptive tracking control scheme based on multi-dimensional …
This paper investigates an adaptive decentralized predefined performance control problem for a class of large-scale nonlinear systems with nonsymmetric input saturation by using …
Subsurface chlorophyll maxima (SCMs), commonly occurring beneath the surface mixed layer in coastal seas and open oceans, account for main changes in depth-integrated primary …
本工作选取多种经典相关系数进行了对比研究,如Pearson相关系数、Spearman相关系数、距离相关系数、最大信息系数及HHG相关系数。具体地,在不同数据规模及噪声水平下,对线性、非线性单调、非单调、非函数等不同类型变量的相关性分别进行研究,得到各相关系数的统计功效。通过分析发现,Pearson相关系数、Spearman相关系数更适合衡量线性、非线性单调相 …
In this paper, the adaptive multi-dimensional Taylor network (MTN) control problem is investigated for nonlinear stochastic systems with full state time-ying constraints and the …
As a prime circulation system, the western Pacific subtropical high (WPSH) significantly impacts tropical cyclone (TC) activities over the western North Pacific (WNP), especially …
In this paper, the problem of adaptive finite-time multi-dimensional Taylor network (MTN) control for a class of stochastic nonlinear systems is investigated. By combining the …
Inthispaper,thedifferenteffectsoftheeasternequatorialPacific(EP)andcentralequatorialPacific(CP)Ocean El Niño–Southern Oscillation (ENSO) events oninterannual variation in the …
在大学数学教学活动中，广大高校数学教师面临的一个突出问题是如何做好教学和科研的融合，有效提升人才培养质量.为了解决这个问题，本文总结了我校数学建模活动促进科教融合的相关举措与实践经验.长期的教学实践表明，构建层次化的建模活动平台，多学科协同育人，是实现数学建模教学常态化、课外实践经常化和应用研究专业化的有效举措.该举措能够培养具有扎实数学应用能力的创新型人才 …
This paper concerns on the control problem of a class of nonlinear systems with input delay and dynamic uncertainties using multi-dimensional Taylor Network (MTN) control method. …
文化创意产业与区域经济之间存在一种相互促进、互为因果的耦合关系。运用动态耦合模型, 对青岛市2008—2019年的文化创意产业与区域经济的动态耦合程度进行实证分析。 结果表明,两者的综合水平均呈现曲折上升趋势,耦合度先上升后降低。 目前,青岛市正处于文化创意产业与区域经济的协调发展阶段,且整个系统将在未来一段时间内长期处于这一发展阶段, 同时,文化创意产业对 …
Marine heatwaves (MHWs) are extreme climatic events that last for days to months and can extend up to thousands of kilometers and cause substantial ecological, social, and economic …
Hyperspectral image (HSI) contains rich spatial and spectral information, which has been widely used in resource exploration, ecological environment monitoring, land cover …
Very high resolution (VHR) satellite and aerial images often suffer from scene occlusion caused by redundant objects. The task of removing these redundant objects can be solved by …
本文解析研究了外加移动载荷下定常流对非线性水弹性波的动力特性。假设流体是不可压缩的、无黏的,运动是无旋的,且所涉及波浪为非线性行进波。首先构建由水动力、弹性力、惯性力和外加载荷作用下的控制方程和非线性边界条件。随后借助同伦分析方法(HAM)求得收敛的近似解析解,着重研究外加载荷的移动速度对水弹波的影响。
The wind stress drag coefficient plays an important role in storm surge models. This study reveals the influences of wind stress drag coefficients, which are given in form of …
Chinese poetry has been a favorite literary genre for thousands of years. Chinese ancient poetry is still being read and practiced, and many famous ancient Chinese poets are …
Targeted observation is an appealing procedure for improving model predictions. However, studies on oceanic targeted observations have been largely based on modeling efforts, and …
The sensitive area of targeted observations for short-term(7 d) prediction of vertical thermal structure(VTS) in summer in the Yellow Sea was investigated. We applied the …
Changes in land cover will cause the changes in the climate and environmental characteristics, which has an important influence on the social economy and ecosystem. The main form …
The increased trends of extreme precipitation events over China have been partially attributed to global warming, while it is unclear how the natural climate iability affect these …
实验室光谱仪是指通过光谱仪仅能获取光谱信号的光谱仪，高光谱相机可通过图像获取图像和光谱两种信息。在使用实验室光谱仪的条件下，针对不同温度、不同实验室的光谱仪、不同测量条件、不同地区间样品等因素的模型转移均已有研究报道，但是，针对高光谱相机与实验室光谱仪之间的模型转移问题的研究较少。本研究以青海 164 份土壤样品为例，获取其实验室光谱仪光谱数据和高光谱相机数 …
We develop a memory graph convolutional network (MGCN) framework for sea surface temperature (SST) prediction. The MGCN consists of two memory layers: one graph layer and one …
This paper proposes a nonlocal fractional peridynamic (FPD) model to characterize the nonlocality of physical processes or systems, based on analysis with the fractional derivative …
We investigate the problem of training an oil spill detection model with small data. Most existing machine-learning-based oil spill detection models rely heavily on big training …
Autumn Arctic sea ice has been declining since the beginning of the era of satellite sea ice observations. In this study, we examined the factors contributing to the decline of …
Autumn Arctic sea ice has been declining since the beginning of the era of satellite sea ice observations. In this study, we examined the factors contributing to the decline of …
Numerical models and correct predictions are important for marine forecasting, but the forecasting results are often unable to satisfy the requirements of operational wave …
This paper investigates the possibility of using machine learning technology to correct wave height series numerical predictions. This is done by incorporating numerical …
Accurately predicting wave height has a significant impact on offshore production and marine transportation. Numerical model predictions are the most commonly used wave height …
Textures contain a wealth of image information and are widely used in various fields such as computer graphics and computer vision. With the development of machine learning, the …
Estimating the ocean subsurface thermal structure (OSTS) based on multisource sea surface data in the western Pacific Ocean is of great significance for studying ocean dynamics …
Organic−inorganic halide perovskites have excellent intrinsic properties, such as long carrier lifetime, high photoluminescence quantum yield, and high gain, in whispering gallery …
The spatiotemporal variability of rainfall in the dry (October-March) and wet (April-September) seasons over eastern China is examined from 1901-2016 based on the gridded rainfall …
次表层叶绿素最大值(subsurface chlorophyll maxima, SCMs)广泛存在于全球各海域,该最大值层往往具有较高的海洋初级生产力和新生产力,因此研究其年际变化特征对深入理解气候变化影响下海洋生态系统变化有重要意义。本文采用一维物理-生态耦合模型 …
Summary In view of the result and performance of control are affected by the existence of input constraints and requirements, adaptive multi‐dimensional Taylor network (MTN) …
Numerous studies have revealed that the sparse spatiotemporal distributions of ground-level PM2.5 measurements affect the accuracy of PM2.5 simulation, especially in large …
研究一类具有有限时间输出约束的切换非线性时滞系统的控制器设计问题.为了在有限时间将输出跟踪误差限制在预定边界内,引入一种改进的有限时间性能函数(FTPF).在控制器的设计过程中,利用障碍Lyapunov函数来解决输出约束问题.然后,将多维泰勒网(MTN)的逼近特性与自适应反步技术相结合,提出一种新的自适应MTN控制方法.在该方法中,通过设计 …
North Pacific ocean desert (NPOD) refers to the subtropical North Pacific Ocean of low chlorophyll-a (Chl-a) concentrations, as the largest ocean desert globally. Studies have …
This paper is concerned with the problem of multi-dimensional Taylor network (MTN) tracking control for a class of nonlinear systems with unknown control direction. By combining …
This paper presents an adaptive multi-dimensional Taylor network (MTN) control approach for a class of nonlinear systems with unknown parameters. MTN is employed to identify …
The Kuroshio Extension (KE) region in the Northwestern Pacific Ocean is one of the most eddy-energetic regions of the global ocean. In the past decades, much has been investigated …
In this paper, an observer-based adaptive Multi-dimensional Taylor network (MTN) controller is proposed for strictly feedback nonlinear systems with time-delay and unmeasurable …
Digital video watermark is widely used to protect copyright and content authentication. DWT-SVD based method, i.e., discrete wavelet transform (DWT) and singular value …
To investigate the effect of wave-induced mixing on the upper ocean structure, especially under typhoon conditions, an ocean-wave coupled model is used in this study. Two physical …
Nonlinear hydroelastic interaction among a floating elastic plate, a train of deepwater waves, and a current which decays exponentially with depth is studied analytically. We …
《数学物理方程与特殊函数》是理工科研究生重要的公共基础课程之一,它在化学、机电、材 料等领域中有着广泛应用,该课程以从物理学及其他技术科学中产生的偏微分方程为研究对象,对方程 的定解问题的建立过程、典型求解方法及解的定性理论进行分析。基于该课程特点及案例教学法的优 点,本文提出将数学建模思想融入该课程教学的案例教学法,并给出交通、工程技术和环境中的典型教学 …
Ocean surface waves are essential to navigation safety, coastal activities, and climate systems. Numerical simulations are still the primary methods used in wave climate research, …
The sea surface temperature (SST) seasonal cycle in the eastern equatorial Pacific (EEP) plays an important role in the El Niño–Southern Oscillation (ENSO) phenomenon. However, the …
作为一种新兴的网络结构,胶囊网络用向量输出替代标量输出,能够捕捉图像特征之间的空间关系,改善卷积神经网络的局限性。首先对胶囊网络进行训练实现图像分类,得到图像的预测类标签,判定出查询图像的所属类别,然后将网络的数字胶囊层中的特征参数作为图像的特征向量,在查询图像的所属类别集合中利用图像特征向量找到与查询图像相似的图像。分别在FASHION-MNIST和 …
基于Angstrom-Prescott模型和空间插值法构建了山东省各地的月太阳辐射估算方法,并利用山东省3个国家站(济南、莒县和福山)和菏泽、聊城、淄博及青岛的辐射观测数据验证了估算方法的准确性。首先利用山东省3个国家站1992年—2015年的辐射与日照百分率观测数据,采用最小二乘法拟合得到不同月份Angstrom-Prescott模型系数并以2016年观测 …
In this paper, a new framework for stress analysis of three-dimensional (3D) composite (multi-layered) elastic materials is presented. In our computations, the composite material …
In recent years, due to the rapid development of Chinese textile industry, the domestic demand for cotton increases sharply. Conversely, the cotton plantation area increasingly …
The local connection characteristics of convolutional neural network (CNN) are linked with the local spatial correlation of image pixels for water depth retrieval in this article. …
Hybrid perovskites have recently attracted attention in both materials science and opto-electronics research, because of their excellent opto-electronic properties and facile …
Both the Arctic and Antarctic sea ice extents (SIEs) from 44 coupled models in the Coupled Model Intercomparison Project Phase 6 (CMIP6) are evaluated by comparing them with …
Microwave technology has been widely used in rubber industry. In order to solve the problem of uneven temperature distribution, a novel control method of adaptive …
When it comes to feature retention in multi-scale representations of ocean flow fields, not all data points are equal. Therefore, this paper proposes a method of selecting data …
To improve the accuracy and efficiency of measuring fracturing proppant sphericity and roundness, a measurement scheme is designed by combining fuzzy connectedness and shape …
Calibration transfer between hyperspectral cameras and conventional spectrometers remains a key challenge for quantitative soil nutrient analysis. This study collected 164 soil …
In this paper, the output feedback adaptive multi-dimensional Taylor network (MTN) tracking control for a class of nonlinear systems with unmeasurable states is investigated. …
Owing to its distinctive merits, non-orthogonal multiple access (NOMA) techniques have been utilized in unmanned aerial vehicle (UAV) enabled wireless base stations to provide …
In this paper, the existence and uniqueness of response solutions, which has the same frequency ω with the nonlinear terms, are investigated for a quasiperiodic singularly …
针对不同波源下微波加热多层橡胶复合材料,建立基于Maxwell方程的一维非稳态有源加热偏微分方程(PDE)模型,以丁苯橡胶材料和丁腈橡胶材料复合为例,采用时域有限差分法进行模拟仿真,研究多层(两层)橡胶复合材料在单/双波源下材料厚度和微波功率对加热温度场和界面特性的影响。结果表明:微波功率变化会影响多层橡胶复合材料加热温度分布;在叠加橡胶材料的交界面处,微波 …
Matching pursuit is an effective method for seismic data decomposition. The traditional matching pursuit has one single objective that successively maximizes the inner products …
Orthogonal matching pursuit (OMP) is an efficient method for decomposing a seismic trace with regard to an atom dictionary. The original OMP optimizes one unique single objective …
In this paper, a multi-dimensional Taylor network (MTN)-based adaptive tracking control approach is proposed for a class of switched nonlinear systems with input nonlinearity. …
In this paper, the output feedback adaptive multi-dimensional Taylor network (MTN) tracking control for a class of nonlinear systems with unmeasurable states is investigated. …
Accurate prediction of the traffic state has received sustained attention for its ability to provide the anticipatory traffic condition required for people’s travel and traffic …
In this paper, an adaptive decentralized control approach is proposed for a class of large-scale nonlinear systems with unknown dead-zone inputs using neural network. Firstly, the …
The impacts of different wave spectrum formulations with high frequency tail on the Stokes drift are studied in this paper. Two wave spectrum formulations are described. One is …
Triangulated irregular networks (TINs) are widely used in terrain visualization due to their accuracy and efficiency. However, the conventional algorithm for multi-scale terrain …
太阳辐射的预估研究对太阳能资源的有效利用有重要意义。应用山东省福山、莒县、济南三所气象站2000—2003年的数据,建立Elman神经网络模型,对日总辐射曝辐量进行时间序列预估研究。结果表明:Elman神经网络预估效果受天气状况影响较大,晴好天气下日总辐射预估结果较精确,福山站预估与观测差值最小,范围在-2～2 MJ·m~ (-2)。城市大气污染对日曝辐量影 …
The prediction ability of the climate system is highly depended on the efficient integration of observations and simulations of the Earth, which is regarded as a canonical example …
In this study, water levels observed at tide stations in the Bohai Sea, Yellow Sea, and East China Sea during Typhoons 7203 and 8509 were assimilated into a numerical assimilation …
In this paper, we investigate the texture synthesis method generated from the hand-made sketches. In recent years, GANs have been vigorously studied in the field of image synthesis …
As the most significant interannual variability in the climate system, El Niño-Southern Oscillation (ENSO) has critical effects on global weather and climate patterns. To simulate …
Introduction: We aimed to estimate the frequency of each AT(N) (beta-amyloid deposition [A], pathologic tau [T], and neurodegeneration [N]) profile in different clinical diagnosis …
针对土壤养分光谱检测中特征波长优选问题，提出一种多分类器融合的特征波长提取方法。以不同地区土壤样品为研究对象，采集可见-近红外光谱，测定总碳、总氮、总磷含量；采用连续投影算法（SPA）、无信息变量消除法（UVE）、遗传算法（GA）、相关系数法（CC）提取特征波长，引入投票法与加权投票法融合多算法结果，利用偏最小二乘回归（PLSR）构建预测模型。结果表明，多分 …
文章基于2015年中国综合社会调查数据和省际截面数据,采用SE-DEA和Ologit模型结合的方法实证研究了公众对政府环保成效的满意程度。结果表明,公众无法准确评价政府环保成效,并且在政府环保成效较高的地区,公众对政府环保工作满意程度评价有下降趋势。此外,环保投资率、环保劳动力投入率以及环保工资的比率与政府环保工作的公众满意度均为正向相关关系。因此,提升公众 …
研究了漂浮在流体表面的超大型浮体的非线性水弹性响应。基于special Cosserat板理论将浮体简化为弹性Plotnikov and Toland板,在势流理论的框架下控制方程和反映水动力、惯性力和弹性力耦合作用的边界条件。运用同伦分析方法分析了一些重要参数对板的水弹性相应的影响,并比较了将浮体简化为非线性板和简化为线性板的差别。结果发现在较小板挠度情形 …
In this paper, an adaptive neural output feedback control scheme based on backstepping technique and dynamic surface control (DSC) approach is developed to solve the tracking …
In this paper, an adaptive neural output feedback control scheme based on backstepping technique and dynamic surface control (DSC) approach is developed to solve the tracking …
In this paper, an observer-based adaptive neural tracking control approach is proposed for a class of stochastic nonlinear systems with immeasurable states. The radial basis …
Nowadays, over 90 percent of the medical data comes from the medical image. People can reduce the medical faults in diagnoses by using computer to analyze and process these medical …
针对运动目标检测中ViBe算法的鬼影、阴影和噪声干扰问题,本研究提出一种融入改进混合高斯模型(GMM)的ViBe算法。该算法改进混合高斯模型的自适应性,使混合高斯模型的K值与学习率对背景进行自适应调节;对视频帧进行训练,构造\"虚拟\"背景代替第一帧图像进行背景建模,算法能够有效地提取背景建模初始化的视频运动目标,从而消除鬼影现象。该算法用像素分类法提取前景 …
运用超效率数据包络分析法(SE-DEA)模型和固定效应回归模型探究中国\"十二五\"期间环境规制效率的时空差异和驱动机制。结果表明:(1)\"十二五\"时期,中国的环境规制综合效率平均值在0.86～1.16范围内波动,产生波动的原因主要是投入的环境保护资源被利用的程度不同。(2)\"十二五\"时期,中国环境规制综合效率、纯技术效率和规模效率均呈现东部地区 …
针对视频中运动目标的提取问题,提出一种基于形态学的高斯模型和八邻域帧差法相融合的提取算法。该算法首先将视频中某些帧转化为灰度图,建立以混合高斯分布为基础的统计模型,并结合八邻域帧差法提取出运动目标的大致轮廓,然后利用自适应更新的高斯模型算法进行精确的减除,最后再进行形态学处理,从而使检测出的运动目标更加清晰完整。实验结果表明,该算法对含有低速运动物体、阴影较 …
Highlights•We propose a new sea surface temperature inversion model.•The model is based on deep neural network.•This model is more accurate than traditional method.•The model is …
The compressive sampling matching pursuit (CoSaMP) algorithm is widely used in orthogonal frequency division multiplexing (OFDM) underwater acoustic (UWA) sparse channel estimation …
This study revisits the Arctic sea ice extent (SIE) for the extended period of 1979–2015 based on satellite measurements and finds that the Arctic SIE experienced three different …
Based on tropical cyclone (TC) track data and gridded observational rainfall data of CN05.1 during the period of 1961 to 2014, we examine the contribution of TCs on three metrics …
Haze particles as a key air pollutant contain high level of toxins, which were hypothesized to inhibit phytoplankton growth when deposited to the ocean, and thus indirectly affect …
This study compares the interdecadal variations in tropical cyclone (TC) activities over the western North Pacific (WNP) basin during the peak season (July–September) and late …
Fog has recently become a frequent high-impact weather phenomenon along the coastal regions of North China. Accurate fog forecasting remains challenging due to limited …
US EPA's Community Multiscale Air Quality modeling system (CMAQ) with Process Analysis tool was used to simulate and quantify the contribution of individual atmospheric processes …
采用广义回归神经网络(generalized regression neural network,GRNN)模型对山东烟台市福山气象站2000～2003年日总辐射曝辐量进行预估。模型通过交叉验证方法确定其关键参数(光滑因子),以日照时数、平均气压、平均气温、日最高气温、相对湿度、气溶胶光学厚度6个变量作为输入量。结果显示:GRNN15.9%,均方根误差为 …
This paper takes the map load as the evaluation indicator for multi-scale representations of ocean flow fields using Euler method. First, the map load of the ocean flow fields is …
Similarity learning plays a fundamental role in the fields of multimedia retrieval and pattern recognition. Prediction of perceptual similarity is a challenging task as in most …
目前,世界气候研究计划（WCRP）组织的国际耦合模式比较计划（CMIP）已经进入到第六阶段（CMIP6),CMIP6试验的开展也已成为国内外地球系统模式工作组的首要工作之一。自然资源部第一海洋研究所地球系统模式FIO-ESM是以耦合自主开发的海浪模式为特色的地球系统模式。在参与CMIP5的FIO-ESM v1.0的基础上,通过升级分量模式、改进海气通量相关物 …
The seasonal prediction of sea surface temperature (SST) and precipitation in the North Pacific based on the hindcast results of The First Institute of Oceanography Earth System …
海洋数值模式是定量描述海洋物理现象及其变化的数值模型,也是海洋与气候研究、预测的核心工具。随着海洋观测的不断投入与积累、对海洋认识的不断深入,特别是在高性能计算技术的支撑下,海洋数值模式已有了长足进步,正朝着高分辨率和多物理过程的方向发展。随着分辨率的提高、物理过 程的细 化,海洋数值模式的发展面临着多个方面的挑战。当前,海洋数据数量和种类不断增多,同时超级 …
本文研究了垂向速度呈指数形式分布的有旋剪切流作用下浮体的非线性动力特性。引入流函数构建控制方程和非线性边界条件。对于浮体为无限长板情形,运用同伦分析方法,得到收敛的近似解析解。结果表明,顺水剪切流使得波峰更尖锐、波谷更平坦,而顺水剪切流的作用则相反;同向的行进波和剪切流使得波速增加,而波流反向时波速减小。
In this paper, the form of a right linear map preserving the left spectrum of quaternion matrices of order 2 is characterized. The obtained conclusion is different from the …
Using the data of three M eteorological Stations at Fushan, Jiʼnan and Juxian, 2000-2003, the Elman neural network model was established to estimate the daily solar irradiance. The …
Although visible-near-infrared spectroscopy can rapidly and accurately determine soil nutrients without sample destruction,some problems remain unresolved, such as the mismatch of …
为了更好地保护图像版权信息,本工作结合超混沌系统和RBF神经网络,提出一种基于超混沌的RBF神经网络模型加密算法,根据JND(最小可视觉误差)模型实现水印的自适应嵌入,并应用RBF神经网络进行水印信息盲检测。实验研究表明:该算法复杂度较低、容易实现,并且具有良好的安全性、不可感知性和鲁棒性。
Let and be a right quaternion linear map from the set of matrices over the quaternion division ring into itself such that the set of matrices over the complex field is invariant …
The generalized finite difference method (GFDM) is a relatively new meshless method for the numerical solution of certain boundary value problems. The method uses the Taylor series …
Mesh denoising is of great practical importance in geometric analysis and processing. In this paper we develop a novel L0sparse regularization method to robustly and reliably …
The interfacial Dzyaloshinskii-Moriya interaction (iDMI) was observed in the bilayer consisting of a heavy metal and a ferromagnetic insulator such as Pt vertical bar Tm3Fe5O12 …
Observations and analyses from the Variational Doppler Radar Assimilation and Analysis System (VDRAS) were used to investigate the convection initiation mechanism of a nocturnal …
从整车物流的具体实例出发,首先,根据给定的轿运车和乘用车的规格,以轿运车运能最大化为目标,求得轿运车的最佳配载方案;其次,以多目的地不同订单需求等为约束,以轿运车使用数量最少和成本最低为目标函数,建立整车配载运送优化模型;最后,利用整单和零单的思想和方法,对优化模型求解,得出轿运车的最佳配载运送方案.所提出的求解方法能大大缩小解的搜索空间,提高运算效率,对解 …
In order to improve the reliability of moving objects detection and tracking, this paper presents a method for moving object real-time detection and tracking based on Vibe and …
Due to the high cost of ocean observation system, the scientific design of observation network becomes much important. The current network of the high frequency radar system in the …
The current main stream researches on state fragility are mostly focusing on the social, political, ecological and economic aspects. However, as one of the most critical issues on …
Dust deposition is an important nutrient source to the South China Sea (SCS), but few in situ experiments were conducted on phytoplankton response to the deposition. We conducted …
The Kuroshio Extension (KE) region is the key area in mid-latitude ocean-atmosphere interaction where mesoscale eddies achieve their largest activity. The eddy-mean flow …
In this paper, multi-dimensional Taylor network (MTN) tracking control scheme is proposed for a class of stochastic nonlinear systems with unknown input dead-zone. The …
The independent point scheme (IPS) is applied to inverting initial condition with the adjoint method for the ocean pollutant transport model in this work. As an improvement, the …
Fog that refers to the concentration of ice or water droplets in the near surface air is an important short-time meteorological phenomenon. As the measure of visibility of air …
针对视频版权的保护,提出了一种基于改进的JND模型的视频水印算法。此算法首先选取二值图像作为图像水印,利用Logistic混沌映射对图像进行加密;然后对载体视频进行关键帧提取,将提取的帧进行4层小波分解,结合分形理论对小波系数进行D树和R树的存储,并根据人类视觉系统(HVS)提出改进的JND模型,进而将处理后的水印信息按照三个方向自适应的嵌入到D树和R树中。 …
本文研究了在剪切流和深水行进波的共同作用下超大型海洋浮体(VLFS)的非线性水弹性响应问题。针对垂向速度呈指数分布的有旋剪切流情形,提出引入流函数构建物理模型的方法,并运用不依赖于任何物理小参数的同伦分析方法(HAM)求得收敛的近似解析解。最后利用计算结果详细讨论了几种重要物理量对板的非线性水弹性响应的影响,我们发现指数剪切流与行进波同向时,涡量越大板的波形 …
The diurnal cycle of sea surface temperature (SST) plays an important role in the upper ocean and climate system. One way to represents the diurnal variation of SST in Ocean …
The majority of studies on texture analysis focus on classification and generation, and few works concern perceptual similarity between textures, which is one of the fundamental …
The Arctic near-surface air temperatures are increasing more than twice as fast as the global average–a feature known as Arctic amplification (AA). A modified AA index is …
In a stratified water column, the nitracline is a layer where the nitrate concentration increases below the nutrient-depleted upper layer, exhibiting a strong vertical gradient in …
针对视频版权的保护,提出一种基于Chebyshev混沌神经网络的视频水印算法。首先选取二值图像作为图像水印,利用Chebyshev混沌神经网络对图像进行加密;然后对宿主视频进行分帧处理,通过Henon映射产生混沌序列提取关键帧,同时提取关键帧亮度分量的低频系数,将处理后的图像水印自适应地嵌入小波变换后亮度分量的低频系数中。实验结果表明,该算法具有较好的不可见 …
针对数字图像版权的保护,本文提出了一种小波域内基于分形理论的零水印算法。首先对载体图像进行Haar小波变换,接着对小波低频系数进行分形编码,通过分形匹配获得图像的重要特征信息;然后建立特征信息与图像水印之间的关系,进行水印的双重嵌入;由于算法没有对图像进行任何修改就完成了水印的嵌入,很好地解决水印鲁棒性与不可见性之间的矛盾。仿真实验结果表明,算法对常见的图像 …
The ensemble Kalman filter (EnKF) performs well because that the covariance of background error is varying along time. It provides a dynamic estimate of background error and …
Because fog is a high-impact weather phenomenon, there has been increased demand for its accurate prediction. Both surface data and wind profiler data possess great potential for …
High-speed underwater wireless transmission technologies are urgently demanded to transmit three-dimensional high-resolution observation data timely in ocean exploration. …
本发明涉及视频图像处理技术领域,尤其涉及一种基于分形理论的小波域视频水印方法。在水印的嵌入过程中,首先分别对提取的关键帧和水印图像同时进行小波变换并进行小波树D和小波树R分解,然后直接乘以强度系数对应嵌入其中。本发明的基于分形理论的小波域视频水印方法提供了一种向视频中嵌入水印的方法,能够对视频版权进行有效的保护,解决了视频容量大、计算复杂度高,水印嵌入困难的 …
Effects of underlying uniform current on the nonlinear hydroelastic waves generated due to an infinite floating plate are studied analytically, under the hypotheses that the fluid …
Sparse approximation has shown to be a significant tool in improving image restoration quality, assuming that the targeted images can be approximately sparse under some transform …
本文解析研宄了在均匀流作用下漂浮在流体表面的无限长薄板的非线性水弹性响应。 在势流理论框架下， 假设流体是无粘的、 不可压缩的，运动是无旋的。 我们以拉普拉斯方程为控制方程， 在板同场中构建非线性动力学和运动学边界条件。借助同伦分析方法求得速一度势、 板挠度的收敛近似解析解； 并深入考査了些重要物理量对非线性水弹动力特性的影响。其中发现薄板的非线 …
随着网络、个人存储设备的发展,数字图像的传播也越来越便捷。但是,恶意篡改、盗用数字图像的现象也日益严重,所以保护数字图像的版权是亟待解决的问题。提出一种基于小波分析的数字水印方法,利用小波域内的JND(最小视觉误差)模型,对载体图像的小波系数进行修改,完成水印嵌入,进而达到保护数字图像版权的目的。实验结果表明,水印的不可感知性很好,在抵抗平滑、中值滤波、椒盐 …
主要研究了单/多列车运行优化控制问题.首先建立了面向节能的单列车能耗优化模型,采用节能控制策略对模型进行求解,得出节能运行的速度距离曲线;其次对多列车多区段的节能运行进行优化控制设计,以再生能量利用最大化为目标,分别建立多列车能耗优化通用模型和高峰/非高峰情形下优化模型,利用模拟退火算法求解模型,得出使总能耗最低的列车运行方案;最后针对晚点情况下追踪运行的多 …
针对数字图像版权的保护,本文提出了一种基于分形的小波域数字图像水印算法。首先将载体图像进行Haar小波变换,将小波系数树分为同方向小波树,并在同方向小波树中构造域子树和值子树,通过分形匹配将域子树分为嵌入域子树和非嵌入域子树,然后在嵌入域子树中加入水印。在水印嵌入时,只嵌入部分水印信息来减少水印的嵌入量,同时运用人类视觉系统HVS模型控制水印嵌入的强度,保证 …
The Arctic sea ice minimum records appeared in the Septembers of 2007 and 2012, followed by high snow cover areas in the Northern Hemisphere winters. The snow cover distributions …
Energy consumption of hotel can be a hot topic in smart city. To find the key impact factors of energy consumption to realize the energy saving target. This paper examined the …
In this paper, we analyzed the correlation relationship among PM2.5 from other five Air Quality Indices(AQIs) based on the grey relational degree, and built a multivariate …
本文首先对直杆在太阳下的影长变化进行分析,建立影长变化模型,并画出给定时间和地点的直杆影长变化曲线;其次,根据所给直杆影子顶点的坐标数据,建立经纬度模型并利用遗传算法求解,确定直杆所处的地点及观测日期;最后对所给视频进行采样分析,将采样帧中的影子顶点坐标转化成现实世界中的坐标,然后求出影长,利用经纬度模型求得视频拍摄的地点及日期。
准确、快速解析混合样品的组成比例，对食品与农产品加工过程的质量控制和配方设计具有重要作用。传统解决方法多依赖大量代表性样品建立统计模型，耗时耗力。本研究以醇类及酸类液体混合样品、以无近红外特征吸收的四氯化碳为溶剂的低浓度溶液混合样品的透射光谱，以及片状烟叶样品漫反射光谱为研究对象，采用导数光谱与S.G.平滑预处理，结合非负回归系数回归法（配方回归），验证了该 …
Abstract With global warming and declining Arctic sea ice area in autumn observed by satellites since 1979, anomalous cold snaps in recent winters have affected large parts of …
Using Ensemble Adjustment Kalman Filter (EAKF), two types of ocean satellite datasets were assimilated into the First Institute of Oceanography Earth System Model (FIO-ESM), v1.0. …
图像是网络多媒体传播的重要对象,因此网络内图像的所有权、版权认证及内容完整性问题也就成了网络安全亟待解决的问题。为了解决该问题,本文提一种Logistic混沌映射和小波分解相结合的数字水印算法。在水印加密与水印嵌入过程中同时引入混沌映射,使水印的安全性能得到了提升。
Effects of the sharp stratification of fluid density on the nonlinear hydroelastic waves traveling in an infinite elastic plate floating on a two-layer inviscid fluid are …
Westerly wind trends at 850 hPa over the Southern Ocean during 1979–2011 exhibit strong regional and seasonal asymmetries. On an annual basis, trends in the Pacific sector …
In order to identify and quantify intrinsic errors in the atmosphere–land and ocean–sea ice model components of the Community Earth System Model version 1 (CESM1) and their …
Recently atmospheric and oceanic observations indicate the tropical Pacific is at the El Niño condition. However, it’s not clear whether this El Niño event of this year is …
北极海冰范围从１９７９年有卫星观测资料以来呈现明显下降趋势，尤其是９月份。２０１２年９月，北极海冰范围达到有观测记录以来的最小值，而２０１３年９月比２０１２年同期增加了６０％。增加的区域主要在东西伯利亚海区、楚科奇海和波弗特海区。本文应用距平和经验模态分解方法，分析了美国国家冰雪数据中心的北极海冰卫星数据、欧洲预报中心的夏季底层大气环流数据和上层海洋的温度， …
Satellite records show the minimum Arctic sea ice extents (SIEs) were observed in the Septembers of 2007 and 2012, but the spatial distributions of sea ice concentration reductlon …
信息媒体的数字化为信息的保存和提取提供了极大的方便,随着数字媒体的传送空间不断扩大,传送时间也在不断缩短,数字产品在发布和传送过程中很容易被侵权、盗版或随意篡改。本文针对图像信息的版权、所有权和内容完整性的保护等问题,利用低位水印技术,重点解决图像信息认证问题,以实现对图像信息的版权、所有权和内容完整性保护及双方责任鉴定等功能。
In this paper, an annular neural network model with three neurons and delays is considered. Time delay can be regard as a source of instability, so that regarding the time-delay τ …
In this paper, 1945--2012 years seawater temperature and salinity data analysis of the vertical structure of temperature and salinity, heat content, temperature and salinity. The …
A nonlinear short-crested wave system, consisting of two progressive waves propagating at an oblique angle to each other in a fluid of finite depth, is investigated by means of an …
A bell-shaped vertical profile of chlorophyll a (Chl a) concentration, conventionally referred to as a subsurface chlorophyll maximum (SCM) phenomenon, has frequently been observed …
在我国金融开放度日益深化的条件下,银行服务质量与效率决定其市场竞争力。近年随着商业银行零售业务的快速发展,我们逐渐意识到排队问题是影响银行服务质量和水平的重要因素.本文在排队论的基础上,利用统计的方法,针对银行窗口排队问题,建立数学模型,以实现银行窗口的设置和排队的优化,为银行服务系统提供有益的参考。
The nonlinear hydroelastic response of very large floating structures (VLFSs) or an ice sheet floating on the surface of deep water, idealized as a semi-infinite thin elastic …
The annual cycle of sea surface temperature (SST) in the eastern equatorial Pacific (EEP) has the largest amplitude in the tropical oceans, but it is poorly represented in the …
Rossby Wave is asort of planetary-scale wave with major influence in marine science and atmospheric science. It has long wavelength and propagates slowly. People can only study it …
In the South China Sea (SCS), the subsurface chlorophyll maximum (SCM) is frequently observed while the mechanisms of SCM occurrence have not been well understood. In this study, a …
云计算安全问题是限制云计算发展的主要问题,一直是IT界研究的热点。介绍了云计算的特点和服务模式,总结了云计算的安全问题,最后根据云计算的层次架构探讨了解决各层次安全问题的安全策略,并在此基础上提出了一种云计算安全框架。
本文研究了一种基于SURF视频分割和小波变换的改进的视频水印算法。首先介绍了基于SURF快速鲁棒特征点的视频分割方法,并采用该方法对源视频进行分割处理;然后再对分割出的每个视频段进行ICA分析,并且得到一系列独立分量帧;最后以这些独立分量帧作为载体,利用小波变换实现水印的嵌入。
基于Jenkins(1989)建立的包含Stokes漂流、风输入和波耗散影响的修正Ekman模型,采用Paskyabi等(2012)使用的推广的Donelan等(1987)中的谱和波耗散函数,并利用Paskyabi等(2012)中修正方法给出的包含高频波的风输入函数,在粘性不依赖于水深及粘性随深度线性变化的条件下,研究了包含高频毛细重力波的随机表面波对 …
We consider a class of two- dimensional nonlinear dynamic system with a forced term on a time scale T and obtain sufficient conditions for all solutions of the system to be …
An analytic approximation method known as the homotopy analysis method (HAM) is applied to study the nonlinear hydroelastic progressive waves traveling in an infinite elastic plate …
借助时间尺度的有关理论,运用不动点定理和不等式技巧研究时间尺度上一类非线性动力系统的渐近性和振动性。给出具有某种渐近性的非振动解存在和所有解振动的充要条件,推广并改进已有某些结果。
随着经济的快速发展,公允价值取代历史成本作为会计计量属性的趋势日益显著,然而由于公允价值尚处于发展的初级阶段,人们对于公允价值计量的可靠性存在着一定的质疑,对其理解还不够全面,相关原则、法规及应用指南也有待于完善,本文从公允价值可靠性的定义入手,分析了可靠性的影响因素,并提出了一些提高公允价值可靠性的建议。
Nowadays, one of the most common approaches for video watermarking is to use singular value decomposition in the discrete wavelet transform domain. In our prior work, we formulated …
The nonlinear hydroelastic waves propagating beneath an infinite ice sheet floating on an inviscid fluid of finite depth are investigated analytically. The approximate series …
We consider a class of nonlinear two-dimensional dynamic systems of the neutral type (x(t) - a(t)x(tau(1)(t)))(Delta) = p(t)f(1)(y(t)), y(Delta)(t) = -q(t)f(2)(x(tau(2)(t))). We …
随着经济的快速发展,公允价值取代历史成本作为会计计量属性的趋势日益显著,然而由于公允价值尚处于发展的初级阶段,人们对于公允价值计量的可靠性存在着一定的质疑,对其理解还不够全面,相关原则、法规及应用指南也有待于完善,文章从公允价值可靠性的定义入手,分析了可靠性的影响因素,并提出了一些提高公允价值可靠性的建议。
借助时间尺度上的有关理论和不动点定理,研究一类较为广泛的时间尺度上高阶带强迫项非线性中立型动力方程,建立该类方程非振动解存在的充要条件。所得结果推广和改进了已有的结论,并通过一个例子阐述主要结果。
One of the common problems of the coupled atmosphere-ocean general circulation models (AOGCMs) without flux correction is that the simulated sea surface temperature (SST) deviates …
We consider the nonlinear dynamic system x(Delta)(t) = a(t)g(y(t)), y(Delta)(t) = -f(t, x(sigma)(t)). We establish some necessary and sufficient conditions for the existence of …
The Argo temperature and salinity profiles in 2005–2009 are assimilated into a coastal ocean general circulation model of the Northwest Pacific Ocean using the ensemble adjustment …
This paper investigates the impact of the parallel computational uncertainty due to the round-off error on climate simulations using the Community Climate System Model Version 3 …
针对金融市场中不同资产之间的尾部相关结构的非对称性和动态性,并通过分析几种常见的Copula函数在相关性分析上的优劣,本工作创新之处是构建了具有尾部变结构的Copula-GARCH模型。相比于单一的、静态的Copula函数,它具有多个Copula函数的混合特性。最后以上证综指和深证成指为例进行分析,结果表明:该模型能够更准确地描述投资组合中金融时间序列之间的 …
利用电子地图中透明度视觉变量产生的虚实感,在对当前焦点时刻时空内容进行完全表达的同时,以不同透明度图形对时间上下文中的内容进行辅助表达,实现兼顾焦点时刻和时间上下文的时空可视化。该方法能够从时间全局上描绘时空对象的时间分布和时态关系,帮助把握时空发展的趋势和规律,同时更加高效地利用地图幅面,时空信息量更加丰富。
This paper presents AutoSaver to balance the performance and resource utilization for a web application in virtualization environment. It consists of a feedback utilization …
海洋中叶绿素垂直分布极不均匀，次表层叶绿素最大值(SCMs)是其中一种主要表现形式，普遍存在于大洋及沿岸海域。次表层叶绿素最大值层（SCML）的深度、厚度与强度是表征海洋SCMs特征的三个主要因子，由海洋水文环境、营养盐分布以及浮游植物种类等因素共同决定。掌握SCMs特征因子的分布规律及主要控制因素，进而发展适合不同海区特点的叶绿素垂直分布模式，对估算海区初 …
Resource allocation for multi-tier web applications in virtualization environments is one of the most important problems in autonomous computing. On one hand, the more resources …
借助时间尺度上的有关理论和Banach压缩映射原理,研究一类较为广泛的时间尺度上高阶带强迫项中立型动力方程正解的存在性。建立该类方程正解存在的几个新的充分条件,并给出一个例子验证所得结果。
云计算为人们方便快捷地完成多媒体信息的存储与处理提供了良好的服务平台,但如何保护云内多媒体信息的版权、所有权和内容完整性成为制约云计算发展的瓶颈问题。本文通过介绍公共云内信息存储方法,针对目前公共云服务所存在的多媒体信息安全认证问题提出相应的策略,并在此基础上探讨了云计算中多媒体信息安全认证框架。
An ensemble adjustment Kalman filter (EAKF) is used to assimilate Argo profiles of 2008 in a global version of the Modular Ocean Model version 4. Four assimilation experiments are …
This paper studies mean square robust exponentially stability of uncertain stochastic systems, With the help of linear matrix inequality theory and Lyapunov function, and taking …
One of the challenges faced by the climate model of the Community Climate System Model version 3 (CCSM3) is the spuriously simulated semi-annual cycle of the sea surface …
被誉为IT界\"工业革命\"的云计算已经开始了其普及化的道路。传统的单点登录方式已经满足不了其对安全性的需求。提出了一个新的双因子登陆模型,使认证码的产生变得动态化且不再需要网络进行传播,从而可使用户登录信息的安全性得到很大程度的保障。
云计算数据库安全问题是制约云计算发展和应用的关键问题之一。首先介绍了云计算数据库的中心管理模式,然后分析了云计算数据库的优点,探讨了云计算数据库的缺陷以及目前所存在的安全问题,最后针对存在的问题提出一些安全策略。
Cloud computing is regarded as one of the most enticing technologies and potential silver bullet in the IT industry. Because of open condition and general-purpose nature of cloud, …
列车编组计划是编组站完成列车调度和组织工作的指导性文件之一,编制科学的列车编组计划是提高运输效率的重要保证。主要探讨了列车编组计划问题的建模、模型计算与求解的方法、编组计划的制定等问题。首先根据某站一天过站列车的数据,以白班和夜班的最小中时为指标,建立了列车解体和编组的优化模型。然后利用遗传算法和Matlab遗传算法工具箱对其进行了求解,最后给出了该站的列车 …
Almost surely asymptotic stability of the trivial solution of linear stochastic system with ime-varying de-lays is discussed , and is extended to the nonlinear stochastic …
An ensemble adjustment Kalman filter system is developed to assimilate Argo profiles into the Northwest Pacific MASNUM wave-circulation coupled model, which is based on the …
云计算的安全问题是影响和制约云计算应用和发展的关键问题,得到了广大科研人员的高度重视。从信息安全的角度出发,深入研究了云计算的可靠性、可用性、保密性、完整性、可控性和不可抵赖性等问题,并在此基础上探讨和设计了云计算的安全框架。
自从数据库诞生以来,其安全问题就一直受到了人们的关注,而数据库的身份验证是保障其安全性的最重要的一道防线,为防止验证密码被泄露盗用,将传统的26位仿射变换算法扩展到31位,并运用Java语言设计了一个密码自动随时间变化的加密解密器,将其引入数据库的密码验证程序后必会使其安全性大大提高。
提出了一个无几何数据冗余的河网渐进式传输多尺度数据结构。结合目标层次的河流选取和几何细节层次上的曲线化简建立河网多尺度数据结构。基于该数据结构,在Web环境下实现了河网数据的渐进式传输。
In this paper, a new VaR (Value-at-Risk) model of portfolios is established: factor APGARCH-M (factor Asymmetric Power GARCH-M), which is based on principal component analysis and …
An optimal interpolation assimilation model for satellite altimetry data is developed based on Princeton Ocean Model (POM), which is applied in a quasi-global domain, by the method …
本文通过运用高等代数中的矩阵方法解决随机变量独立性的判定问题,并且用随机变量的性质证明了高等代数中的两个重要不等式,说明了高等代数、概率论在解决问题过程中的相互渗透,揭示了它们之间的内在联系。
由于风险值VaR具有一定局限性,因此人们在VaR的基础上又提出了一种新的度量市场风险的方法:尾部条件期望TCE。利用GED分布和T分布的TGARCH-M模型建立计算公式,并实证比较了VaR和TCE度量市场风险的准确性,结果表明,在通常情况下TCE和VaR均能较准确地度量市场风险。
建立一种新的度量风险值(VaR)模型PGARCH-M(PowerGARCH-M),并利用该模型,通过对工业指数和地产指数的VaR计算,得出基于GED分布的PGARCH-M模型估计VaR极端值更为精确,优于基于正态分布的PGARCH-M模型和PGARCH模型。
提出一种新的图像混沌置乱及加密方法,利用2个耦合混沌映射产生混沌序列对,利用该序列对通过变换形成图像像素新的地址码,对原始图像进行混沌置乱,得到置乱图像。对乱序图像进行离散余弦变换(DCT),在DCT域内利用一个混沌序列对每个系数进行改变,从而对图像进行加密。恢复图像时,其解密和反置乱过程与上述过程相反。仿真实验结果表明,该方法简单易行,具有较强的安全性和可 …
提出了一种新的图像混沌置乱及加密的方法,首先利用2个耦合混沌映射产生一系列混沌序列对,利用该序列对形成图像像素新的地址码,对原始图像进行混沌置乱,从而得到乱序图像;其次对乱序图像进行DCT,在DCT域内再利用一个混沌序列对每一个系数进行自适应的改变,完成对图像的加密过程,图像的解密和反置乱过程与上述过程正好相反。为了验证本方法的安全性和可靠性,对其进行了仿真 …
在海气耦合模式CCSM3基础上引入波致混合作用后建立了改进的海气耦合模式, 设计了SST 同化方案, 并进行了2005, 2006和2007年ENSO 的集合后报和2008年气候预测数值试验.结果表明, 改进的海气耦合模式的同化效果优于原来的海气耦合模式CCSM3的同化效果.集合后报与观测资料对比表明:改进的海气耦合模式能够较好地预测当年ENSO事件的发生情 …
The paper presents a novel and robust video watermarking scheme based on fractal theory in DCT domain of every I-frame of video stream. Firstly, we select I-frames from video …
This paper proposes a new and secure video encryption method based on chaotic maps in DCT domain, which is quite in keeping with the common ideas and the frequent practices of …
Based on the development mechanism of BA growing networks, by a bipartite graph a model has been given which aims at a stationary growing social collaboration-competition network …
考虑时间测度上一阶线性超前型微分方程解的振动性,我们建立了这类方程的解振动的充分条件,所得结论包含了微分方程和差分方程的有关结果,同时,我们的结论也包括了更多种情况。
采用包含环境因素的多部门内生经济增长模型,讨论发展中区域的环境经济问题,探讨发展中区域环境经济可持续发展的可能性及相关的最优控制策略,为分析发展中区域环境经济提供了可行的模型和方法。
为了提高图像水印的鲁棒性和不可见性,结合小波变换和分形变换,提出了一种基于小波域内分形变换的图像数字水印方法。首先对图像进行小波变换,结合图像空域分形编码思想把图像的小波系数分成域子树和值子树两类,然后利用分形仿射变换选出具有相似性的域子树,将其作为水印的嵌入树,结合人类视觉系统的JND模型实现水印的嵌入和提取,最后针对该方法进行了JPEG压缩、剪切、滤波、 …
建立了多个同类企业的投资竞赛数学模型,运用稳定性理论,对系统不动点的稳定性做出分析,给出企业间投资保持均衡态势时参数的取值范围,并分析了其经济学意义.通过数据仿真验证了理论分析的正确性.
将模糊综合评判的数学方法应用于教师课堂教学质量的评估体系,建立了数学模型,对模型中的一级指标和二级指标分别采用德尔斐法和专家赋分的方法确定各评价指标权重。用此模型对被测教师的课堂教学质量进行了全面评价,并与专家评价结果进行比较,结果表明该模型具有较好的实用性。
信息与计算科学专业是一门新兴的理科专业,探索如何办好本专业是一项较有意义的工作,调整课程体系,拓宽专业口径,将信息与计算融为一体,是专业建设的新途径,另外,文章还初步讨论了信息与计算科学专业的实践教学和师资队伍建设问题。
随着招生规模的不断扩大,各高校学生的整体素质有所下降,并且个体差异很大,这给高等数学教学带了前所未有的难度,为了改变这一现状,一些院校开展了分层次教学改革的尝试,笔者根据多年来分层次教学改革的经验,深入探讨了高等数学分层次教学的必要性、意义、具体实施方案等,提出了建设性的对策和建议,并对自己的教学实践进行了详细的总结和分析。
Ocean forecasting with a General Circulation Model (GCM) commonly begins from an initial analysis obtained by data assimilation. Instead of a single initial state, bred-ensemble …
A common problem in the application of the coupled ocean-atmosphere general circulation models (CGCMs) without flux correction is that the simulated equatorial cold tongue in …
The scheme in this paper carries out embedding and detecting of watermarking by the fractal technology in DWT domain. This method introduces the threshold control, searches for the …
Copyright protection becomes a more and more important problem with the development of the creation and distribution of 3D model. The paper proposes a novel and robust watermarking …
Copyright protection becomes a more and more important issue with the rapid development of the creation of 3D model. The paper proposes a novel robust watermarking scheme for 3D …
Image encryption becomes more and more important with the development of the network technology and the multimedia technology. A novel and secure image encryption method based on …
The paper presents a novel and robust video watermarking scheme for copyright protection based on chaos, DWT and JND model of HVS. Firstly, in order to ensure security of …
The issue of Information security in the transmit process becomes more and more urgent with the development of the network technology and the information technology. A novel scheme …
针对单一金融产品和由多种资产组成的投资组合两种情况,用几只股票的历史收盘数据实证比较了两种先进的度量金融市场风险测度———风险值(VaR)和尾部条件期望(TCE)的有效性。结果显示,TCE比VaR更有效。
Underwater wireless sensor networks (UWSNs) have been shown to overcome the environmental extremes and energy dependency issues faced by traditional IoT in marine environments, …
For Underwater Internet of Things (UIoT) applications, the accurate and efficient estimation of the direction of arrival (DOA) is fundamental to technologies such as node …
Hydroacoustic signal demodulation plays a crucial role in underwater communication systems. Recently, deep learning-based methods have gained popularity due to their ability to …
