Results 51 to 60 of about 57,925 (177)
The Interpretability and Predictability of Time-varying and Contagious Jumps to the Financial Markets [PDF]
, 2016 本文就时变及传染性跳跃对金融市场的解释和预测进行研究。具体而言，本文从理论和实证两方面就时变及传染性跳跃是否能够预测股票市场收益及波动率，是否有助于解释外汇市场之谜和研究汇率可预测性以及会如何影响高频期货与期权市场投资者行为进行了深入研究。我们首先将LPW模型和Du模型中的固定跳跃强度变换成服从自回归条件跳跃强度过程和平方贝塞尔过程的时变跳跃强度，然后应用校准出的时变跳跃溢价来预测市场超额收益及波动率。结果显示在样本内和样本外所有的跳跃溢价都具有显著的预测能力。在美国市场上 ...
郭宇强
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Insights for conservation from the Ecological Knowledge Games project
Conservation Biology, EarlyView.Abstract Environmental conservation research requires robust methods for collecting large‐scale behavioral data and engaging diverse stakeholders in decision‐making processes. We (Y.P., A.B.D., and N.B.) created EcoKnowGames (Ecological Knowledge Games), a transdisciplinary project that develops knowledge games for conservation science and data ...
Yuan Pan +4 more
wiley +1 more source
Jingshui jishu【目的】针对人工调控主导的水库型水源地水位变化规律复杂、传统预测方法精度不足的难题，本文旨在构建并验证一种物理信息融合的多模块机器学习耦合预测框架，以实现对此类水库水位的合理且兼具高时效性的预测，为水库的精细化调度提供决策支持。【方法】本文将该预测框架应用于JZ水库，对水库内运行机理不同的调控单元进行定制化建模：(1)对引水闸门流量预测采用双层级联模式，基于先知模型(Prophet)的闸门开度时序预测与基于极端梯度提升(XGBoost)的流量系数(C d )动态估计 ...
Zhang Wu
doaj +1 more source
Housing Price shocks、Macroeconomic Volatility and Monetary Policy [PDF]
, 2014 随着近二十年来全球范围的房地产繁荣与萧条周期循环，以及住房财富在家庭财富中所占比重的增长，越来越多的学者开始关注于房地产市场波动对宏观经济金融的冲击；尤其是2007年美国次贷危机之后，房价冲击对宏观经济的传导机制及其货币政策反应再次成为学者们关注的焦点。当前，全球经济正经历着艰难而曲折的复苏之路，中国也面临深刻的经济转型。在此背景下，本研究报告综合运用比较静态分析、动态最优化、门限模型、协整检验等理论与实证研究方法，揭示房价冲击向通胀、产出、家庭消费等宏观经济变量的传导机制 ...
段忠东
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Behavioral interventions to reduce demand for threatened freshwater turtles as pets
Conservation Biology, EarlyView.Abstract Growing demand for freshwater turtles as pets has fueled illegal trade and accelerated wild population declines, underscoring the need for theory‐based demand‐reduction interventions. We conducted a three‐part randomized controlled trial with active turtle keepers (n = 1800) in China to test conservation‐ and legality‐framed messages by ...
Wuji Zheng +9 more
wiley +1 more source
Gaoya dianqi, 2018 文中提出了一种基于改进支持向量机的变压器实时热点温度预测方法。该方法以变压器负载电流、环境温度和顶层油温为特征值,将变压器热点温度预警与预测相结合,目的在于实现基于近期历史运行数据的变压器实时热点温度预测。文中研究分析了基于改进网格搜索、遗传算法及粒子群算法的支持向量机在变压器短期热点温度预测中的应用效果,结果表明,3种改进方法均可有效提升预测精度,但基于改进网格搜索算法的支持向量机预测效率最高。最后,以某35 k V油浸式变压器实时热点温度数据为样本集,文中所述方法可有效实现变压器短期热点温度预警预测,
廖才波 +5 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT Although the use of AI technologies (e.g., chatbots and automated writing evaluations (AWE)) has gained considerable attention in language learning fields in recent years, how AI technologies have been designed and implemented in language learning education, as well as their effectiveness, is understudied.
Shen Qiao +2 more
wiley +1 more source
Assessment and Prediction of the Impact of Trade Liberalization on China's Carbon Emissions: Empirical Studies Based on GTAP Database [PDF]
, 2016 当今世界处于两个全球性进程，即经济全球化和气候变化的“双重暴露（doubleexposure）”之下。贸易自由化已经成为经济全球化的重要内容及目标，同时城市工业化进程的加快以及发展中国家经济的快速发展，导致大气中温室气体浓度增加并带来极端天气，这使得全球气候变化成为国际社会面临的重要挑战。作为全球化的两个进程，贸易自由化和气候变化之间相互联系、相互作用。一方面，已有研究表明，贸易自由化政策将通过影响经济系统的经济规模、经济结构、生产技术，进而影响生产过程中的能源消耗、能源结构、能源利用效率等 ...
余丽丽
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Profiling Metacognitive Knowledge and Growth Mindset in EFL Vocabulary Learning
International Journal of Applied Linguistics, EarlyView.ABSTRACT Guided by the self‐regulated learning (SRL) framework, the present study investigates the associations between metacognitive knowledge and growth mindset in EFL (English as a Foreign Language) vocabulary learning, addressing a critical gap in the literature. While metacognitive knowledge, comprising person, task, and strategy dimensions, plays
Weili (Allen) Xing, Mark Feng Teng
wiley +1 more source
Research on Energy Efficiency Optimization Algorithm for Copper Flash Smelting Process Based on Data-driven [PDF]
, 2016 铜闪速熔炼工序具有多变量、非线性、大时滞、强耦合、生产波动大的特点，传统的基于机理模型的优化控制系统很难适应多变的运行条件，预测结果偏差较大，影响最终的控制效果。随着计算机技术的发展，复杂工业过程中积累了大量生产数据，为我们从人工智能的角度进行建模与优化控制提供了数据基础。 本论文以某大型闪速炼铜企业的闪速熔炼生产过程为研究对象。为了实现铜闪速熔炼工序中的节能减耗，本文提出了一种满足三大工艺指标（冰铜品位，冰铜温度，渣中铁硅比）约束的能效优化模型：首先 ...
董云成
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