Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Survival Tree01:19

Survival Tree

105
Survival trees are a non-parametric method used in survival analysis to model the relationship between a set of covariates and the time until an event of interest occurs, often referred to as the "time-to-event" or "survival time." This method is particularly useful when dealing with censored data, where the event has not occurred for some individuals by the end of the study period, or when the exact time of the event is unknown.
 Building a Survival Tree
Constructing a...
105
Classification of Systems-II01:31

Classification of Systems-II

171
Continuous-time systems have continuous input and output signals, with time measured continuously. These systems are generally defined by differential or algebraic equations. For instance, in an RC circuit, the relationship between input and output voltage is expressed through a differential equation derived from Ohm's law and the capacitor relation,
171
Classification of Systems-I01:26

Classification of Systems-I

211
Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity.
Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as:
211
Multi-input and Multi-variable systems01:22

Multi-input and Multi-variable systems

127
Cruise control systems in cars are designed as multi-input systems to maintain a driver's desired speed while compensating for external disturbances such as changes in terrain. The block diagram for a cruise control system typically includes two main inputs: the desired speed set by the driver and any external disturbances, such as the incline of the road. By adjusting the engine throttle, the system maintains the vehicle's speed as close to the desired value as possible.
In the absence...
127
Per-Unit Sequence Models01:26

Per-Unit Sequence Models

93
An ideal Y-Y transformer, grounded through neutral impedances, displays per-unit sequence networks akin to those of a single-phase ideal transformer when subjected to balanced positive- or negative-sequence currents. These currents do not produce neutral currents, and their associated voltage drops.
Zero-sequence currents, which are identical in magnitude and phase, generate a neutral current, resulting in voltage drops across the neutral impedance and the low-voltage winding. If the...
93
Aggregates Classification01:29

Aggregates Classification

344
Aggregate classification is generally based on its size, petrographic characteristics, weight, and source. Size classification ranges from coarse to fine aggregates, defined by the size of the particles. Coarse aggregates are particles that do not pass through ASTM sieve No. 4, and aggregates that pass through the sieve are fine aggregates.
Petrographic classification groups aggregates based on common mineralogical characteristics. Some of the common mineral groups found in aggregates are...
344

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Phenotypic, genomic, and functional characterization of Corynebacterium sp. nov. isolated by droplet-based cultivation from vaginal swabs of a preeclampsia patient.

BMC microbiology·2026
Same author

Distinct vaginal microbial signatures in pregnancies complicated by antiphospholipid syndrome: depletion of <i>Lactobacillus johnsonii</i> and enrichment of <i>Bifidobacterium dentium</i>.

Microbiology spectrum·2026
Same author

A microbiota-host axis mediates prostaglandin sensitivity: Lactobacillus crispatus as a biomarker and regulator of human labor induction.

NPJ biofilms and microbiomes·2026
Same author

Photoinduced intramolecular S-α-C(sp<sup>3</sup>)-H functionalization enabled by an electron donor-acceptor complex-Mediated radical relay.

Chemical science·2026
Same author

Prognostic value of micro-RNA in ovarian cancer: a systematic review and meta-analysis.

Frontiers in oncology·2026
Same author

Targeted delivery to joints of the rheumatoid arthritis drug betulin using folic acid-coated nanoparticles based on human serum albumin.

International journal of biological macromolecules·2026

相关实验视频

Updated: Jul 16, 2025

Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis
06:56

Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis

Published on: September 22, 2023

1.1K

在基于TreeLSTM的复杂数据库系统中使用一个核心值估计器.

Kaiyang Qi1, Jiong Yu1,2, Zhenzhen He2

  • 1School of Software, Xinjiang University, Urumqi 830091, China.

Sensors (Basel, Switzerland)
|September 9, 2023
PubMed
概括

这项研究引入了一个新的TreeLSTM神经网络,以更准确地估计数据库查询的核心值. 新模型通过更好地处理复杂的查询和多个表相关性来改善查询优化.

科学领域:

  • 数据库管理系统数据库管理系统
  • 人工智能的人工智能
  • 机器学习 机器学习

背景情况:

  • 准确的枢密度估计对于数据库查询优化至关重要.
  • 传统方法难以处理多表相关性和复杂查询.
  • 现有的基于学习的方法有希望,但仍有局限性.

研究的目的:

  • 为复杂的SQL查询开发一个先进的枢密度估计模型.
  • 为了提高数据库系统中查询优化的准确性.
  • 为了解决当前基于学习的核心值估计技术的局限性.

主要方法:

  • 提出了一个基于采样的树长短期记忆 (TreeLSTM) 神经网络.
  • 将SQL查询建模为树,考虑预言关系和连接相关性.
  • 引入了一种新的损失函数,以提高跨不同枢密度尺度的估计准确性.

主要成果:

  • 树LSTM模型在核心值估计方面表现出卓越的表现.
  • 在现实数据集上表现优于传统方法和其他深度学习方法.
  • 在Q误差,平均绝对误差 (MAE) 和对称平均绝对百分比误差 (SMAPE) 中取得了显著改进.
关键词:
核心值估计的核心值估计深度学习是一种深度学习.查询优化 查询优化树长期短期记忆 树长期短期记忆

更多相关视频

Executing Complexity-Increasing Queries in Relational MySQL and NoSQL MongoDB and EXist Size-Growing ISO/EN 13606 Standardized EHR Databases
07:26

Executing Complexity-Increasing Queries in Relational MySQL and NoSQL MongoDB and EXist Size-Growing ISO/EN 13606 Standardized EHR Databases

Published on: March 19, 2018

9.4K
Large-scale Reconstructions and Independent, Unbiased Clustering Based on Morphological Metrics to Classify Neurons in Selective Populations
12:27

Large-scale Reconstructions and Independent, Unbiased Clustering Based on Morphological Metrics to Classify Neurons in Selective Populations

Published on: February 15, 2017

7.0K

相关实验视频

Last Updated: Jul 16, 2025

Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis
06:56

Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis

Published on: September 22, 2023

1.1K
Executing Complexity-Increasing Queries in Relational MySQL and NoSQL MongoDB and EXist Size-Growing ISO/EN 13606 Standardized EHR Databases
07:26

Executing Complexity-Increasing Queries in Relational MySQL and NoSQL MongoDB and EXist Size-Growing ISO/EN 13606 Standardized EHR Databases

Published on: March 19, 2018

9.4K
Large-scale Reconstructions and Independent, Unbiased Clustering Based on Morphological Metrics to Classify Neurons in Selective Populations
12:27

Large-scale Reconstructions and Independent, Unbiased Clustering Based on Morphological Metrics to Classify Neurons in Selective Populations

Published on: February 15, 2017

7.0K

结论:

  • 拟议的TreeLSTM模型有效地捕捉了复杂的查询结构和多表连接关系.
  • 这种方法显著提高了枢密度估计的准确性和质量.
  • 该方法为优化复杂的数据库查询提供了一个有希望的解决方案.