期刊文献+
共找到1,674篇文章
< 1 2 84 >
每页显示 20 50 100
Dual-doping for enhancing chemical stability of functional anionic units in sulfide for high-performance all-solid-state lithium batteries
1
作者 Peiwen Yu Niaz Ahmad +6 位作者 Jie Yang Chaoyuan Zeng Xiaoxiao Liang Weiming Huang Mei Ni Pengcheng Mao Wen Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期382-390,I0009,共10页
The sulfide-based solid-state electrolytes(SEs)reactivity toward moisture and Li-metal are huge barriers that impede their large-scale manufactu ring and applications in all-solid-state lithium batteries(ASSLBs).Herei... The sulfide-based solid-state electrolytes(SEs)reactivity toward moisture and Li-metal are huge barriers that impede their large-scale manufactu ring and applications in all-solid-state lithium batteries(ASSLBs).Herein,we proposed an Al and O dual-doped strategy for Li_(3)PS_(4)SE to regulate the chemical/electrochemical stability of anionic PS_(4)^(3-)tetrahedra to mitigate structural hydrolysis and parasitic reactions at the SE/Li interface.The optimized Li_(3.08)A_(10.04)P_(0.96)S_(3.92)O_(0.08)SE presents the highestσLi+of 3.27 mS cm^(-1),which is~6.8 times higher than the pristine Li_(3)PS_(4)and excellently inhibits the structural hydrolysis for~25 min@25%humidity at RT.DFT calculations confirmed that the enhanced chemical stability was revealed to the intrinsically stable entities,e.g.,POS33-units.Moreover,Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)SE cycled stably in Li//Li symmetric cell over 1000 h@0.1 mA cm^(-2)/0.1 mA h cm^(-2),could be revealed to Li-Al alloy and Li_(2)Oat SE/Li interface impeding the growth of Li-dendrites during cycling.Resultantly,LNO@LCO/Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)/Li-In cell delivered initial discharge capacities of 129.8 mA h g^(-1)and 83.74%capacity retention over 300 cycles@0.2 C at RT.Moreover,the Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)SE presented>90%capacity retention over 200 and 300 cycles when the cell was tested with LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA)cathode material vs.5 and 10 mg cm^(-2)@RT. 展开更多
关键词 Dual doping High Li^(+) conductivity Air-stability Pos_(3)^(3-) functional units Stable SE/electrode interface
下载PDF
Block copolymer electrolyte with adjustable functional units for solid polymer lithium metal battery 被引量:2
2
作者 Zhiyuan Lin Xianwei Guo +3 位作者 Yubo Yang Mingxue Tang Qi Wei Haijun Yu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第1期67-74,I0003,共9页
Solid polymer electrolytes have been considered as the promising candidates to improve the safety and stability of high-energy lithium metal batteries.However,the practical applications of solid polymer electrolytes a... Solid polymer electrolytes have been considered as the promising candidates to improve the safety and stability of high-energy lithium metal batteries.However,the practical applications of solid polymer electrolytes are still limited by the low ionic conductivity,poor interfacial contact with electrodes,narrow electrochemical window and weak mechanical strength.Here,a series of novel block copolymer electrolytes with three-dimensional networks are designed by cross-linked copolymerization of the polyethylene glycol soft segments and hexamethylene diisocyanate trimer hard segments.Their ionic migration performances and interface compatibilities with Li metal anode have been optimized delicately by tailoring the ratio of these functional units.The optimized block copolymer electrolyte has shown an amorphous crystalline structure,a high ionic conductivity of ~5.7×10^(-4)S cm^(-1),high lithium ion transference number(~0.49),wide electrochemical window up to ~4.65 V(vs.Li+/Li) and favorable mechanical strength at 55℃.Furthermore,the enhanced interface compatibility can well support the normal operations of lithium metal batteries using both LiFePO4 and LiNi0.8Co0.15Al0.05O2 cathodes.This study not only paves a new way to develop solid polymer electrolyte with optimizing functional units,but also provides a polymer electrolyte design strategy for the application demand of lithium metal battery. 展开更多
关键词 Block copolymer electrolyte functional units Ionic migration performance Interface compatibility Lithium metal battery
下载PDF
SCHWARZ-PICK ESTIMATES FOR PARTIAL DERIVATIVES OF ARBITARY ORDER OF BOUNDED HOLOMORPHIC FUNCTIONS IN THE UNIT BALL OF C^n 被引量:5
3
作者 戴绍虞 陈怀惠 《Acta Mathematica Scientia》 SCIE CSCD 2011年第4期1624-1632,共9页
This paper gives a Schwarz-Pick estimate for bounded holomorphic functions in the unit ball of C n .
关键词 unit ball holomorphic function Schwarz-Pick estimate
下载PDF
Incremental multivariable predictive functional control and its application in a gas fractionation unit 被引量:3
4
作者 施惠元 苏成利 +3 位作者 曹江涛 李平 宋英莉 李宁波 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4653-4668,共16页
The control of gas fractionation unit(GFU) in petroleum industry is very difficult due to multivariable characteristics and a large time delay.PID controllers are still applied in most industry processes.However,the t... The control of gas fractionation unit(GFU) in petroleum industry is very difficult due to multivariable characteristics and a large time delay.PID controllers are still applied in most industry processes.However,the traditional PID control has been proven not sufficient and capable for this particular petro-chemical process.In this work,an incremental multivariable predictive functional control(IMPFC) algorithm was proposed with less online computation,great precision and fast response.An incremental transfer function matrix model was set up through the step-response data,and predictive outputs were deduced with the theory of single-value optimization.The results show that the method can optimize the incremental control variable and reject the constraint of the incremental control variable with the positional predictive functional control algorithm,and thereby making the control variable smoother.The predictive output error and future set-point were approximated by a polynomial,which can overcome the problem under the model mismatch and make the predictive outputs track the reference trajectory.Then,the design of incremental multivariable predictive functional control was studied.Simulation and application results show that the proposed control strategy is effective and feasible to improve control performance and robustness of process. 展开更多
关键词 gas fractionation unit multivariable process incremental predictive functional control
下载PDF
THE ASYMPTOTIC FORMULA OF THE ORTHOGONAL RATIONAL FUNCTION ON THE UNIT CIRCLE
5
作者 Zhu Laiyi People’s Universityy of China, China 《Analysis in Theory and Applications》 1993年第2期24-36,共13页
In this paper we obtained the asymptotic formula of the orthogonal rational function on the unit circle with respect to the weight function μ(z) with preasigned poles, which are in the exterior of the unit disk.
关键词 PRO RATIONAL THE ASYMPTOTIC FORMULA OF THE ORTHOGONAL RATIONAL function ON THE unit CIRCLE 六丁
下载PDF
Uniqueness Theorem of Algebroidal Function in the Unit Disc
6
作者 ZHANG Xiao-mei SUN Dao-chun 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第3期357-363,共7页
In this paper, discussed are the problems about uniqueness of algebroidal functions in the unit disc with share-values in a sector domain instead of the whole disk. Results are obtained extending some uniqueness theor... In this paper, discussed are the problems about uniqueness of algebroidal functions in the unit disc with share-values in a sector domain instead of the whole disk. Results are obtained extending some uniqueness theorems of meromorphic functions. 展开更多
关键词 algebroidal function UNIQUENESS unit disk
下载PDF
A SCHWARZ LEMMA FOR HARMONIC FUNCTIONS IN THE REAL UNIT BALL
7
作者 Shaoyu DAI Huaihui CHEN 《Acta Mathematica Scientia》 SCIE CSCD 2019年第5期1339-1344,共6页
We establish a precise Schwarz lemma for real-valued and bounded harmonic functions in the real unit ball of dimension n. This extends Chen's Schwarz-Pick lemma for real-valued and bounded planar harmonic mapping.
关键词 HARMONIC functionS Schwarz-Pick LEMMA unit BALL
下载PDF
针对性气道护理对重症监护室患者舒适度与呼吸机相关性肺炎的影响 被引量:1
8
作者 周晓玲 邵小燕 +2 位作者 丁菊红 龚亚驰 陆玉梅 《护理实践与研究》 2024年第1期106-111,共6页
目的探讨针对性气道护理模式在重症监护室(ICU)患者中的应用效果。方法选择2021年1月—2022年12月医院120例ICU患者,按组间基线资料可比的原则将其分为对照组和观察组,每组60例。对照组予以常规护理,观察组采用针对性气道护理。观察两... 目的探讨针对性气道护理模式在重症监护室(ICU)患者中的应用效果。方法选择2021年1月—2022年12月医院120例ICU患者,按组间基线资料可比的原则将其分为对照组和观察组,每组60例。对照组予以常规护理,观察组采用针对性气道护理。观察两组患者护理干预前、护理干预5 d后的呼吸状况及舒适度,比较其康复进程、导管堵塞情况及呼吸机相关性肺炎(VAP)发生情况。结果观察组患者护理干预5 d后的PaO_(2)水平高于对照组,组间比较差异有统计学意义(P<0.05)。PaCO_(2)水平低于对照组,组间比较差异有统计学意义(P<0.05)。观察组患者护理干预5 d后的Kolcaba舒适状况量表(GCQ)评分高于对照组,差异有统计学意义(P<0.05)。观察组患者机械通气时间及ICU治疗时间分别为6.50±1.08 d和7.84±1.50 d,短于对照组的7.22±1.36 d和8.68±1.74 d,差异有统计学意义(P<0.05);观察组患者机械通气期间的导管堵塞程度较对照组轻,且VAP发生率低于对照组,差异均有统计学意义(P<0.05)。结论针对性气道护理模式可改善ICU患者呼吸状况及舒适度,缩短康复进程,并可减轻患者机械通气治疗期间导管堵塞程度,降低VAP发生率。 展开更多
关键词 气道护理 重症监护室 呼吸功能 呼吸机相关性肺炎 舒适度
下载PDF
Composite Cost Function Based Solution to the Unit Commitment Problem
9
作者 Srikrishna Subramanian Radhakrishnan Anandhakumar 《Smart Grid and Renewable Energy》 2010年第2期88-97,共10页
This paper presents a new approach via composite cost function to solve the unit commitment problem. The unit com-mitment problem involves determining the start-up and shut-down schedules for generating units to meet ... This paper presents a new approach via composite cost function to solve the unit commitment problem. The unit com-mitment problem involves determining the start-up and shut-down schedules for generating units to meet the fore-casted demand at the minimum cost. The commitment schedule must satisfy the other constraints such as the generating limits, spinning reserve, minimum up and down time, ramp level and individual units. The proposed algorithm gives the committed units and economic load dispatch for each specific hour of operation. Numerical simulations were carried out using three cases: four-generator, seven-generator, and ten-generator thermal unit power systems over a 24 h period. The produced schedule was compared with several other methods, such as Dynamic programming, Branch and bound, Ant colony system, and traditional Tabu search. The result demonstrated the accuracy of the proposed method. 展开更多
关键词 COMPOSITE COST function Generation SCHEDULING unit COMMITMENT
下载PDF
基于深度学习的盾构机土舱压力场预测方法
10
作者 张超 朱闽湘 +2 位作者 郎志雄 陈仁朋 程红战 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第2期307-315,共9页
土舱压力是盾构机受力状态和掌子面稳定等核心问题中的关键因素。土舱压力具有显著的空间变异性,其形成演化机制源于装备与岩土之间的复杂耦合作用,与地质特征、掘进参数等多源参数相关。然而,现有土舱压力预测方法一般未考虑空间分布... 土舱压力是盾构机受力状态和掌子面稳定等核心问题中的关键因素。土舱压力具有显著的空间变异性,其形成演化机制源于装备与岩土之间的复杂耦合作用,与地质特征、掘进参数等多源参数相关。然而,现有土舱压力预测方法一般未考虑空间分布特征或地质参数影响。针对该问题,提出了一种基于空间分布物理特征函数导引深度学习的盾构机土舱压力场预测方法。该方法构建物理特征函数用于解耦土舱压力空间分布特征,采用卷积神经网络和门控循环单元分别提取多源参数历史信息的空间特征和特征系数的时序特征,结合多源参数实时信息对特征系数进行预测,从而实现土舱压力场的预测。以长沙地铁四号线某区段为案例,利用该方法准确预测了土舱压力空间分布实测数据,准确率高达0.98,验证了所提方法的有效性。敏感性分析表明,不同地层中土舱压力空间分布特征系数的主要敏感参数基本一致,但其敏感度随地层地质条件的变化规律差异显著,可为复杂地层盾构机土舱压力精细化调控提供参考。 展开更多
关键词 土舱压力场 卷积神经网络 门控循环单元 物理特征函数 土压平衡盾构机 盾构隧道
下载PDF
基于GRU的仪表着陆系统故障预测方法研究
11
作者 张强 祁江涛 +1 位作者 焦浩博 黄莉莉 《航空工程进展》 CSCD 2024年第3期62-70,共9页
故障预测技术在保障仪表着陆系统的可靠运行、提高空管效能等方面具有重要应用价值。结合仪表着陆系统运行特征和实际运行维护工作,提出一种基于GRU的仪表着陆系统故障预测方法。以航向信标为研究对象,在分析其监控参数与设备运行状态... 故障预测技术在保障仪表着陆系统的可靠运行、提高空管效能等方面具有重要应用价值。结合仪表着陆系统运行特征和实际运行维护工作,提出一种基于GRU的仪表着陆系统故障预测方法。以航向信标为研究对象,在分析其监控参数与设备运行状态之间的关系后,将监控参数作为故障特征参数;根据监控参数时间步长、时变性特征显著的特点,采用GRU预测监控参数的未来变化趋势;根据监控参数的隶属函数计算出参数未来时刻可能发生“故障”的概率,实现对航向信标故障的预测。结果表明:基于GRU的仪表着陆系统预测方法的相对预测精度在95%以上。 展开更多
关键词 仪表着陆系统 故障预测 监控参数 门控循环单元 隶属度函数
下载PDF
美国教师专业标准的功能定位及其背景与动因
12
作者 王静 饶从满 吴宗劲 《外国教育研究》 北大核心 2024年第5期3-17,共15页
标准的功能定位是影响教师标准价值实现的关键因素。而教师标准应该如何进行功能定位不可抽象而论,应置于特定的时空环境中加以审视。在提升教育质量成为压倒性诉求、以问责制为主导话语的教育改革时代,美国却选择了发展导向的教师标准... 标准的功能定位是影响教师标准价值实现的关键因素。而教师标准应该如何进行功能定位不可抽象而论,应置于特定的时空环境中加以审视。在提升教育质量成为压倒性诉求、以问责制为主导话语的教育改革时代,美国却选择了发展导向的教师标准。美国之所以作出如此选择,背后有着教师地位不高进而影响教师供给的客观背景,职业专业主义的思想背景以及分权制背景下美国联邦政府期望透过发展导向教师标准干预教师质量提升的主观考量。 展开更多
关键词 美国 教师 专业标准 功能定位 教师质量
下载PDF
Cost Effective Operating Strategy for Unit Commitment and Economic Dispatch of Thermal Power Plants with Cubic Cost Functions Using TLBO Algorithm
13
作者 E. B. Elanchezhian S. Subramanian S. Ganesan 《Journal of Power and Energy Engineering》 2015年第6期20-30,共11页
This paper deals with a Unit Commitment (UC) problem of a power plant aimed to find the optimal scheduling of the generating units involving cubic cost functions. The problem has non convex generator characteristics, ... This paper deals with a Unit Commitment (UC) problem of a power plant aimed to find the optimal scheduling of the generating units involving cubic cost functions. The problem has non convex generator characteristics, which makes it very hard to handle the corresponding mathematical models. However, Teaching Learning Based Optimization (TLBO) has reached a high efficiency, in terms of solution accuracy and computing time for such non convex problems. Hence, TLBO is applied for scheduling of generators with higher order cost characteristics, and turns out to be computationally solvable. In particular, we represent a model that takes into account the accurate higher order generator cost functions along with ramp limits, and turns to be more general and efficient than those available in the literature. The behavior of the model is analyzed through proposed technique on modified IEEE-24 bus system. 展开更多
关键词 CUBIC COST functionS RAMP Rate TEACHING Learning Based Optimization unit COMMITMENT
下载PDF
大型硫回收装置多功能CO变换加氢催化剂应用总结
14
作者 裴爱霞 《炼油技术与工程》 CAS 2024年第5期53-56,共4页
普光气田是国内成功开发的首个高含硫气田,原料气(天然气)碳硫比高,再生酸性气CO_(2)含量高,会反应生成CO继而生成COS、CS_(2)等有机物,成为影响装置达标排放的关键因素之一。研究开发了具有CO变换功能的克劳斯尾气加氢催化剂,并成功应... 普光气田是国内成功开发的首个高含硫气田,原料气(天然气)碳硫比高,再生酸性气CO_(2)含量高,会反应生成CO继而生成COS、CS_(2)等有机物,成为影响装置达标排放的关键因素之一。研究开发了具有CO变换功能的克劳斯尾气加氢催化剂,并成功应用于中国石化中原油田普光气田天然气净化厂200 kt/a硫回收装置。工业应用结果表明:加氢反应器过程气CO变换率超过90%,在线炉制氢天然气消耗量减少279 m^(3)/h,催化剂加氢转化率、有机硫水解率均超过99%,烟气SO_(2)排放浓度降至200 mg/m^(3)以下,CO排放浓度降低了90%,效益显著。 展开更多
关键词 硫回收装置 多功能 CO变换 加氢催化剂 反应温度 反应空速 活性 有机硫
下载PDF
一种融合注意力机制的CNN-BiGRU磁盘故障预测方法研究
15
作者 王艳 刘亚东 +1 位作者 皮婵娟 施君豪 《大数据》 2024年第5期109-122,共14页
磁盘作为重要的存储介质,一旦出现故障很可能会导致存储数据丢失,给个人及企业带来难以估量的损失。现有磁盘故障预测模型存在不能很好地平衡磁盘数据样本、未充分利用磁盘数据的时序特性等问题。以Backblaze云存储公司公布的真实磁盘... 磁盘作为重要的存储介质,一旦出现故障很可能会导致存储数据丢失,给个人及企业带来难以估量的损失。现有磁盘故障预测模型存在不能很好地平衡磁盘数据样本、未充分利用磁盘数据的时序特性等问题。以Backblaze云存储公司公布的真实磁盘数据为研究对象,提出了一种融合注意力机制的卷积神经网络(CNN)和双向门控循环单元(BiGRU)网络的磁盘故障预测模型。在数据预处理方面,采用负采样与焦点损失函数来平衡正负样本,利用CNN进行特征提取,并结合BiGRU网络来有效地处理时序数据。通过融合注意力机制,能够让模型快速地捕捉更多关键特征信息,将筛选出的特征与数据输入模型进行训练。通过对比其他故障预测模型,本文提出的模型在精确率等4个评价指标上均有1%~7%的性能提升,为提高磁盘存储的可靠性提供了有力的支撑。 展开更多
关键词 注意力机制 磁盘故障预测 双向门控循环单元 卷积神经网络 焦点损失函数
下载PDF
基于SwinT-YOLOX模型的自动扶梯行人安全检测算法
16
作者 侯颖 杨林 +3 位作者 胡鑫 贺顺 宋婉莹 赵谦 《计算机工程》 CAS CSCD 北大核心 2024年第3期277-289,共13页
自动扶梯被广泛应用在公共场合,乘客摔倒事故如果不能被及时发现并处理,会造成严重的人身伤害,因此实现自动扶梯智能化监控管理势在必行。受自动扶梯运行环境复杂、行人多以及局部遮挡情况的影响,传统的人体姿态特征摔倒检测模型效果不... 自动扶梯被广泛应用在公共场合,乘客摔倒事故如果不能被及时发现并处理,会造成严重的人身伤害,因此实现自动扶梯智能化监控管理势在必行。受自动扶梯运行环境复杂、行人多以及局部遮挡情况的影响,传统的人体姿态特征摔倒检测模型效果不佳且检测速度减慢。融合Swin Transformer和YOLOX目标检测算法的优秀策略,提出一种基于SwinT-YOLOX网络模型的自动扶梯行人摔倒检测算法。采用Swin Transformer模型作为骨干网络,颈部网络使用添加注意力机制的YOLOX模型,进一步提升特征图的多样性和表达能力。此外,利用漏斗修正线性单元视觉激活函数构建CBF模块,改进颈部网络和Head网络结构,从而获得更优的特征检测性能。实验结果表明,针对自建扶梯行人摔倒数据库和网络采集实际扶梯行人摔倒事故,与AlphaPose、OpenPose、YOLOv5等算法相比,该算法检测性能明显提高,行人摔倒平均检测精度可以达到95.92%,检测帧率为24.08帧/s,能够快速、精准地检测到乘客摔倒事故发生,监控管理平台立刻采取安全急停措施以保证乘客安全。 展开更多
关键词 自动扶梯 摔倒检测 深度学习 YOLOX模型 Swin Transformer模型 漏斗修正线性单元视觉激活函数
下载PDF
基于特定设计条件分析的空间赋形思维模型构建
17
作者 周琮 房立敏 +1 位作者 门艳红 郑恒祥 《华中建筑》 2024年第7期169-173,共5页
通过讨论“造形问题”在建筑设计中的关键作用,认为设计工作的核心是以空间赋形的方式综合处理各种分支问题,教学内容只有当其直接或间接地与这一过程相关,才具有意义。随后以“环境”和“功能”为主要线索,尝试构建空间赋形的思维模型... 通过讨论“造形问题”在建筑设计中的关键作用,认为设计工作的核心是以空间赋形的方式综合处理各种分支问题,教学内容只有当其直接或间接地与这一过程相关,才具有意义。随后以“环境”和“功能”为主要线索,尝试构建空间赋形的思维模型。结合建筑学二年级的幼儿园课程设计内容,通过教案编排使教学内容与思维模型匹配,达到有效训练“群落式”建筑空间赋形的目的,进而培养学生在建筑入门阶段具备将建筑形态与具体问题结合,在不同因素中获得主导权的设计能力。 展开更多
关键词 形态 空间赋形 环境与功能 群落式空间 思维模型
下载PDF
基于演化博弈的车联网分发消息激励机制
18
作者 王桐 林孟瑜 +1 位作者 欧阳敏 曹越 《应用科技》 CAS 2024年第3期114-120,共7页
由于车联网中节点资源有限,车联网中存在不愿意传递消息的自私车辆节点,严重影响网络性能。为了改善网络性能,提出了一种基于演化博弈的车联网消息合作分发的激励机制,利用节点始终追求最大收益的有限理性的特点,根据节点传递消息的数... 由于车联网中节点资源有限,车联网中存在不愿意传递消息的自私车辆节点,严重影响网络性能。为了改善网络性能,提出了一种基于演化博弈的车联网消息合作分发的激励机制,利用节点始终追求最大收益的有限理性的特点,根据节点传递消息的数量以及节点在固定时间内的空闲程度设计收益函数,引导自私节点努力参与到车联网中消息的传递过程,同时引入路边单元作为监管者加速车辆节点的策略更新过程。仿真结果表明自私节点比例越多,网络性能越差,而该激励机制可以有效地改善存在自私节点的车联网的网络性能。 展开更多
关键词 车联网 自私节点 演化博弈 激励 收益函数 路边单元 数据包投递率 平均传输时延
下载PDF
Predicting Wavelet-Transformed Stock Prices Using a Vanishing Gradient Resilient Optimized Gated Recurrent Unit with a Time Lag
19
作者 Luyandza Sindi Mamba Antony Ngunyi Lawrence Nderu 《Journal of Data Analysis and Information Processing》 2023年第1期49-68,共20页
The development of accurate prediction models continues to be highly beneficial in myriad disciplines. Deep learning models have performed well in stock price prediction and give high accuracy. However, these models a... The development of accurate prediction models continues to be highly beneficial in myriad disciplines. Deep learning models have performed well in stock price prediction and give high accuracy. However, these models are largely affected by the vanishing gradient problem escalated by some activation functions. This study proposes the use of the Vanishing Gradient Resilient Optimized Gated Recurrent Unit (OGRU) model with a scaled mean Approximation Coefficient (AC) time lag which should counter slow convergence, vanishing gradient and large error metrics. This study employed the Rectified Linear Unit (ReLU), Hyperbolic Tangent (Tanh), Sigmoid and Exponential Linear Unit (ELU) activation functions. Real-life datasets including the daily Apple and 5-minute Netflix closing stock prices were used, and they were decomposed using the Stationary Wavelet Transform (SWT). The decomposed series formed a decomposed data model which was compared to an undecomposed data model with similar hyperparameters and different default lags. The Apple daily dataset performed well with a Default_1 lag, using an undecomposed data model and the ReLU, attaining 0.01312, 0.00854 and 3.67 minutes for RMSE, MAE and runtime. The Netflix data performed best with the MeanAC_42 lag, using decomposed data model and the ELU achieving 0.00620, 0.00487 and 3.01 minutes for the same metrics. 展开更多
关键词 Optimized Gated Recurrent unit Approximation Coefficient Stationary Wavelet Transform Activation function Time Lag
下载PDF
大概念统摄下的数学单元教学设计探析——以初中函数为例
20
作者 常宁 胡典顺 《数学教育学报》 北大核心 2024年第2期20-26,共7页
“大概念”和“单元教学”是实现学科核心素养落地的两个关键词.大概念作为知识通往素养的桥梁,强调知识的意义理解与自主迁移,帮助学生形成良好的认知结构和思维方式.大概念统摄下的数学单元教学设计,关注单元的整体性、注重单元的结... “大概念”和“单元教学”是实现学科核心素养落地的两个关键词.大概念作为知识通往素养的桥梁,强调知识的意义理解与自主迁移,帮助学生形成良好的认知结构和思维方式.大概念统摄下的数学单元教学设计,关注单元的整体性、注重单元的结构化、强调单元的素养化,使数学单元层级更为清晰,数学单元设计核心更为明确,是发展学生核心素养的重要途径.其结构要素主要有:命名单元主题、明确大概念群、识别基本问题、制定单元目标、理清形成路径、设计学习活动等.进行大概念统摄下的初中函数单元教学设计,为大概念在素养本位单元教学中的落实提供了一种探索性思路. 展开更多
关键词 大概念 初中函数 单元教学设计 数学核心素养
下载PDF
上一页 1 2 84 下一页 到第
使用帮助 返回顶部