Results 21 to 30 of about 10,420 (169)
Analysis the self-similarity of network traffic in fractional Fourier transform domain [PDF]
, 2013 Statistical characteristics of network traffic data in FrFT domain were analyzed,which indicates the self-simi-larity feature.Further,Hurst parameter estimation methods based on modified ensemble empirical mode decomposi-tion-detrended fluctuation ...
Ju-long LAN +3 more
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Very Short-Term Wind Direction Multistep Forecast Based on VMD-LSTM [PDF]
, 2023 [Introduction] In order to accurately forecast the wind direction in the next 4 hours, a very short-term wind direction multistep forecast algorithm based on VMD-LSTM（Variational Mode Decomposition-Long Short-Term Memory） is proposed.
Desheng MIAO +5 more
core +1 more source
Research on Bonnet Polishing Machine Tool Precision and Optics Surface Mid-spatial Frequency Error Controlling Technique [PDF]
, 2015 大口径自由曲面光学元件广泛应用于强激光装置、大型天文望远镜、卫星用光学系统等大中型光学系统中，随着国家重大光学工程及国防尖端技术对它们的需求量越来越大，实现大口径自由曲面光学元件的高效、高精度加工是光学元件制造领域需要解决的关键问题。抛光加工作为大口径自由曲面光学元件超精密加工的一个重要工序，其材料去除效率、加工精度以及加工表面纹理控制等对光学元件的最终质量有重要影响。气囊抛光技术采用具有一定充气压力的柔性橡胶气囊作为抛光工具，通过选取不同的工艺参数（如气囊充气压力、气囊压缩量、主轴转速、气囊头直径 ...
姜涛
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Rare Metals, EarlyView.ABSTRACT High‐entropy alloys (HEAs) have attracted considerable interest from researchers owing to their tunable chemical compositions, exceptional structural stability, and promising catalytic properties. However, their large‐scale application is often hindered by complex manufacturing techniques and poor durability.
Sheng Guo +9 more
wiley +1 more source
Research on Sand Dumping Detection of Harbor Dredging Based on Signal Enhancement and Feature Extraction [PDF]
, 2016 随着海洋经济发展，各国对港区建设和航道维护愈加重视。但是，在利益驱使下，疏浚驳船常常在非指定区倾倒泥沙，导致航道内泥沙淤积甚至断航，航道维护成本增加和生态坏境破坏。目前，国内普遍采用安装摄像头、吃水线检测等监控方法，但易受人为破坏和环境因素的影响无法获得好的效果。国外采用更改倾倒区和自然处理的手段并不适用于我国流域众多的国情。因此，航道管理部门急需一种非接触式、稳定可靠的监控手段，以保证疏浚工程作业的质量。 本文根据混浊海水声吸收的原理，周期性地发送和接收Chirp探测信号 ...
钟张婷
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Conservation Biology, Volume 40, Issue 1, February 2026.Abstract Spatial segregation in at‐sea distribution is frequently observed in seabirds and can have important implications for conservation and management. Globally, many albatross and petrel populations are declining due to bycatch in fisheries. In South Georgia, the decrease in wandering albatrosses (Diomedea exulans) differs among breeding sites ...
V. Warwick‐Evans +3 more
wiley +1 more source
Generation and Propagation Characteristics of Continental Shelf Wave in the Northern South China Sea [PDF]
, 2016 南海是西北太平洋最大的边缘海，频发的寒潮和热带气旋激发了丰富而活跃的海洋动力过程。强风所激发的陆架波是南海北部陆架区重要的海洋动力过程之一。本文基于验潮站水位数据、潜标海流数据和卫星高度计数据，结合海面风和气压数据、观测站地面气温和气压数据、MODIS影像数据，利用小波变换、交叉小波变换及经验模态分解等数据处理手段，系统地分析了南海北部海域寒潮及热带气旋激发陆架波的特性。 2008年1—3月的强寒潮引起了三次海面水位振荡事件，分别发生在1月9—21日、2月5—18日和2月20日—3月8日。第一 ...
李君益
core
Modeling and Predicting Time Series with Non-stationarity and Volatility [PDF]
The difficulty of time series prediction lies in how to handle non-stationarity and volatility. When dealing with non-stationarity, existing deep learning models adopt a method of stabilizing the input sequences before training, which has problems of ...
FENG Qiang, ZHAO Jianguang, YANG Rong, NIU Baoning
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Deep quantile regression for growth and maturation reaction norms
Methods in Ecology and Evolution, Volume 17, Issue 1, Page 111-124, January 2026.Abstract Understanding species' growth and maturation responses to anthropogenic and environmental pressures is crucial for tracking demographic shifts, phenotypic change and ensuring population sustainability. Traditional regression methods often focus on modelling the conditional mean of life‐history traits, potentially overlooking heterogeneity in ...
Guankui Liu +4 more
wiley +1 more source
Time-Varying Frequency and Statistical Analysis Methods for Biomedical Signals [PDF]
, 2017 生物医学信号由于其产生机理复杂，一般具有信号弱、噪声大、随机性强等特点，所以处理起来十分困难。由此衍生出的算法也是具有多样性。本文回顾了几种经典且常用处理生物医学信号的方法，其中涵盖了基于时域、频域以及时变频率特性的分析方法。结合实际应用，重点介绍了时域分析中的带阻滤波器和自相关函数；频域分析中的功率谱密度；时变频率特性分析中的短时傅里叶变换、小波分析、Wigner-Ville分布、匹配追踪以及集成经验模态分解等。同时还提出了一种新颖的分析信号方法——时变统计特性分析 ...
陈品男
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