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Annotation 7601408576780

#golang-migrate
  • Migrate reads migrations from sources and applies them in correct order to a database.
  • Drivers are "dumb", migrate glues everything together and makes sure the logic is bulletproof. (Keeps the drivers lightweight, too.)
  • Database drivers don't assume things or try to correct user input. When in doubt, fail.
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Unknown title
B Breadcrumbs migrate / README.md Top File metadata and controls Preview Code Blame 195 lines (146 loc) · 8.07 KB Raw migrate Database migrations written in Go. Use as CLI or import as library. <span>Migrate reads migrations from sources and applies them in correct order to a database. Drivers are "dumb", migrate glues everything together and makes sure the logic is bulletproof. (Keeps the drivers lightweight, too.) Database drivers don't assume things or try to correct user input. When in doubt, fail. Forked from mattes/migrate Databases Database drivers run migrations. Add a new database? PostgreSQL PGX v4 PGX v5 Redshift Ql Cassandra SQLite SQLite3 (todo #165) SQLCipher MySQL/ Mari



Annotation 7601410149644

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Unknown title
sure the logic is bulletproof. (Keeps the drivers lightweight, too.) Database drivers don't assume things or try to correct user input. When in doubt, fail. Forked from mattes/migrate Databases <span>Database drivers run migrations. Add a new database? PostgreSQL PGX v4 PGX v5 Redshift Ql Cassandra SQLite SQLite3 (todo #165) SQLCipher MySQL/ MariaDB Neo4j MongoDB CrateDB (todo #170) Shell (todo #171) Google Cloud Spanner CockroachDB YugabyteDB ClickHouse Firebird MS SQL Server Database URLs Database connection strings are specified via URLs. The URL format is driver dependent but generally has the form: dbdriver://username:password@host:port/dbname?param1=tru



Annotation 7601423518988

#golang-migrate

Coming from another db migration tool?

Check out migradaptor. Note: migradaptor is not affliated or supported by this project
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Unknown title
s to come) Migration files Each migration has an up and down migration. Why? 1481574547_create_users_table.up.sql 1481574547_create_users_table.down.sql Best practices: How to write migrations. <span>Coming from another db migration tool? Check out migradaptor. Note: migradaptor is not affliated or supported by this project Versions Version Supported? Import Notes master ✅ import "github.com/golang-migrate/migrate/v4" New features and bug fixes arrive here first v4 ✅ import "github.com/golang-migrate/migra



Annotation 7601501113612

The Go Programming Language Specification (whole document)
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The Go Programming Language Specification - The Go Programming Language
brary Release Notes <div> Packages Community navigate_next navigate_beforeCommunity Recorded Talks Meetups open_in_new Conferences open_in_new Go blog Go project Get connected <div> <span>The Go Programming Language Specification Version of Aug 2, 2023 Table of Contents Introduction Notation Source code representation Characters Letters and digits Lexical elements Comments Tokens Semicolons Identifiers Keywords



Annotation 7601516580108

Definition of Root Locus
根轨迹简称根迹，它是开环系统某一参数从零变到无穷时，闭环系统特征方程式的根在\(s\)平面上变化的轨迹。
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Flashcard 7601518415116

Question
根轨迹简称根迹，它是[...]时，闭环系统特征方程式的根在\(s\)平面上变化的轨迹。
Answer
开环系统某一参数从零变到无穷

statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill

Definition of Root Locus
根轨迹简称根迹，它是开环系统某一参数从零变到无穷时，闭环系统特征方程式的根在\(s\)平面上变化的轨迹。






Flashcard 7601519987980

Question
根轨迹简称根迹，它是开环系统某一参数从零变到无穷时，[...]。
Answer
闭环系统特征方程式的根在\(s\)平面上变化的轨迹

statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill

Definition of Root Locus
根轨迹简称根迹，它是开环系统某一参数从零变到无穷时，闭环系统特征方程式的根在\(s\)平面上变化的轨迹。






Annotation 7601521560844

求取闭环极分布问题的实质
当闭环系统没有零点与极点相消时，闭环特征方程式的根就是闭环传递函数的极点，我们常简称之为闭环极点。因此，从已知的开环零、极点位置及某一变化的参数来求取闭环极点的分布，实际上就是解决闭环特征方程式的求根问题。
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Flashcard 7601523395852

Question
当闭环系统没有零点与极点相消时，闭环特征方程式的根就是闭环传递函数的极点，我们常简称之为闭环极点。因此，从已知的开环零、极点位置及某一变化的参数来求取闭环极点的分布，实际上就是解决[...]。
Answer
闭环特征方程式的求根问题

statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill

求取闭环极分布问题的实质
当闭环系统没有零点与极点相消时，闭环特征方程式的根就是闭环传递函数的极点，我们常简称之为闭环极点。因此，从已知的开环零、极点位置及某一变化的参数来求取闭环极点的分布，实际上就是解决闭环特征方程式的求根问题。






Flashcard 7601528114444

Question
当闭环系统没有零点与极点相消时，闭环特征方程式的根就是闭环传递函数的极点，我们常简称之为闭环极点。因此，从[...]，实际上就是解决闭环特征方程式的求根问题。
Answer
已知的开环零、极点位置及某一变化的参数来求取闭环极点的分布

statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill

求取闭环极分布问题的实质
当闭环系统没有零点与极点相消时，闭环特征方程式的根就是闭环传递函数的极点，我们常简称之为闭环极点。因此，从已知的开环零、极点位置及某一变化的参数来求取闭环极点的分布，实际上就是解决闭环特征方程式的求根问题。






Annotation 7601529687308

根轨迹法的意义
当开环增益或其他参数改变时，其全部数值对应的闭环极点均可在根轨迹图上简便地确定。同时因为系统的稳定性由系统闭环极点唯一确定，而系统的稳态性能和动态性能又与闭环零极点在\(s\)平面上的位置密切相关，所以根轨迹图不仅可以直接给出闭环系统时间响应的全部信息，而且可以指明开环零、极点应该怎样变化才能满足给定的闭环系统的性能指标要求
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Flashcard 7601532308748

Question
当开环增益或其他参数改变时，其全部数值对应的闭环极点均可在根轨迹图上简便地确定。同时因为系统的稳定性由系统闭环极点唯一确定，而系统的稳态性能和动态性能又与闭环零极点在\(s\)平面上的位置密切相关，所以根轨迹图不仅可以[...]，而且可以指明开环零、极点应该怎样变化才能满足给定的闭环系统的性能指标要求
Answer
直接给出闭环系统时间响应的全部信息

statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill

根轨迹法的意义
当开环增益或其他参数改变时，其全部数值对应的闭环极点均可在根轨迹图上简便地确定。同时因为系统的稳定性由系统闭环极点唯一确定，而系统的稳态性能和动态性能又与闭环零极点在\(s\)平面上的位置密切相关，所以根轨迹图不仅可以直接给出闭环系统时间响应的全部信息，而且可以指明开环零、极点应该怎样变化才能满足给定的闭环系统的性能指标要求






Flashcard 7601535192332

Question
当开环增益或其他参数改变时，其全部数值对应的闭环极点均可在根轨迹图上简便地确定。同时因为系统的稳定性由系统闭环极点唯一确定，而系统的稳态性能和动态性能又与闭环零极点在\(s\)平面上的位置密切相关，所以根轨迹图不仅可以直接给出闭环系统时间响应的全部信息，而且可以[...]
Answer
指明开环零、极点应该怎样变化才能满足给定的闭环系统的性能指标要求

statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill

根轨迹法的意义
当开环增益或其他参数改变时，其全部数值对应的闭环极点均可在根轨迹图上简便地确定。同时因为系统的稳定性由系统闭环极点唯一确定，而系统的稳态性能和动态性能又与闭环零极点在\(s\)平面上的位置密切相关，所以根轨迹图不仅可以直接给出闭环系统时间响应的全部信息，而且可以指明开环零、极点应该怎样变化才能满足给定的闭环系统的性能指标要求






Annotation 7601537551628

根轨迹与系统性能的关系

通过分析根轨迹图，可以分析系统的稳定性、稳态性能和动态性能：
- 稳定性：系统根轨迹若不穿过虚轴则系统对所有$K$值都是稳定的；根轨迹若穿过虚轴则$K$值大于系统临界开环增益时系统不稳定

- 稳态性能：暂且略过

- 动态性能：根据系统根轨迹在复平面上的不同位置，可以判断系统输出类型的变化以及临街增益。比如在系统稳定的情况下，根轨迹在实轴上时系统为过阻尼系统，根轨迹在虚轴上时系统为振荡系统，根轨迹在其他位置时系统为阻尼振荡系统
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Flashcard 7601539386636

Question
通过分析根轨迹图，可以分析系统的[系统性能]
Answer

- 稳定性：系统根轨迹若不穿过虚轴则系统对所有\(K\)值都是稳定的；根轨迹若穿过虚轴则\(K\)值大于系统临界开环增益时系统不稳定

- 稳态性能：暂且略过

- 动态性能：根据系统根轨迹在复平面上的不同位置，可以判断系统输出类型的变化以及临街增益。比如在系统稳定的情况下，根轨迹在实轴上时系统为过阻尼系统，根轨迹在虚轴上时系统为振荡系统，根轨迹在其他位置时系统为阻尼振荡系统


statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill

根轨迹与系统性能的关系
通过分析根轨迹图，可以分析系统的稳定性、稳态性能和动态性能






Annotation 7601541745932

相角条件和幅值条件

根轨迹上的点必须满足相角条件和幅值条件：

- 相角条件：\(\begin{gathered}\sum_{j=1}^m \angle\left(s-z_j\right)-\sum_{i=1}^n \angle\left(s-p_i\right)=(2 k+1) \pi \\k=0, \pm 1, \pm 2, \cdots\end{gathered}\)

- 幅值条件：\(K^*=\frac{\prod_{i=1}^n\left|s-p_i\right|}{\prod_{j=1}^m\left|s-z_j\right|}\)
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Flashcard 7601543580940

Question

根轨迹上的点必须满足相角条件和幅值条件：

- 相角条件： [...]

- 幅值条件： [...]

Answer

- 相角条件：\(\begin{gathered}\sum_{j=1}^m \angle\left(s-z_j\right)-\sum_{i=1}^n \angle\left(s-p_i\right)=(2 k+1) \pi \\k=0, \pm 1, \pm 2, \cdots\end{gathered}\)

- 幅值条件：\(\displaystyle K^*= \frac{\displaystyle\prod_{i=1}^n\left|s-p_i\right|}{\displaystyle \prod_{j=1}^m\left|s-z_j\right|}\)


statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill

相角条件和幅值条件
根轨迹上的点必须满足相角条件和幅值条件： - 相角条件：\(∑j=1m∠(s−zj)−∑i=1n∠(s−pi)=(2k+1)πk=0,±1,±2,⋯\begin{gathered}\sum_{j=1}^m \angle\left(s-z_j\right)-\sum_{i=1}^n \angle\left(s-p_i\right)=(2 k+1) \pi \\k=0, \pm 1, \pm 2, \cdots\end{gathered}\) - 幅值条件：\(K^*=\frac{\prod_{i=1}^n\left|s-p_i\right|}{\prod_{j=1}^m\left|s-z_j\right|}\)