320 Matching Annotations
  1. Jul 2021
  2. bafybeic2mwwizbcleyp2to22xtg7gutywzhoiwxcbuumkhpxugdnbaswoq.ipfs.localhost:8080 bafybeic2mwwizbcleyp2to22xtg7gutywzhoiwxcbuumkhpxugdnbaswoq.ipfs.localhost:8080
    1. linear combination of theksolutions

      解的线性组合

    2. omogeneous linearrecurrence relation

      齐次线性递归

    3. non-homogeneous linearrecurrence relation

      非齐次线性递归

    4. derivative

      形式幂级数的导数

    5. quotient formal powerseries

      形式幂级数的商不一定存在

    6. formal power series

      形式幂级数

    7. multiplication rule

      形式幂级数的乘法规则

    8. generating function

      生成函数

    9. characteristic polynomial

      特征多项式

    1. FCFS

      same as SJF

    2. response time
      t0      t1      P       cpu             queue
      0       1       P2      busy                
      1       2       -       cs              [P1]
      2       7       P1      busy                
      7       8       -       cs              [P4,P5,P3]
      8       10      P4      busy
      10      11      -       cs              [P5,P3]
      11      14      P5      busy
      14      15      -       cs              [P3]
      15      19      P3      busy
      
      total response time: (1-0) + (7-2) + (10-4) + (14-7) + (19-8) = 30
      
    3. response time
      t0      t1      P       cpu             queue
      0       1       -       cs              [P2]
      1       2       P2      busy                
      2       3       -       cs              [P1]
      3       6       P1      busy                
      6       7       -       cs              [P4,P1,P5]
      7       9       P4      busy
      9       10      -       cs              [P1,P5,P3]
      10      12      P1      busy
      12      13      -       cs              [P5, P3]
      13      16      P5      busy                
      16      17      -       cs              [P3]
      17      20      P3      busy
      20      21      -       cs              [P3]
      21      22      P3      busy
      
      total response time: (2-0) + (12-2) + (9-4) + (16-7) + (22-8) = 40
      
    4. finish time - the arrival time

      turnaround time

  3. May 2021
  4. bafybeidej4tasx6dk67t6srmq5fhdy32z26kyrsweo2nskxx7eds6y2bgm.ipfs.localhost:8080 bafybeidej4tasx6dk67t6srmq5fhdy32z26kyrsweo2nskxx7eds6y2bgm.ipfs.localhost:8080
    1. Use forward difference approximation. Cannot use central difference approximation

      Neumann 边值条件处理方式

    2. Dirichlet boundary condition

      Dirichlet 边值条件 $$ y(a) = \beta $$

    3. Neumann boundary condition

      Neumann 边值条件 $$ y'(a) = \alpha $$

  5. bafybeidej4tasx6dk67t6srmq5fhdy32z26kyrsweo2nskxx7eds6y2bgm.ipfs.localhost:8080 bafybeidej4tasx6dk67t6srmq5fhdy32z26kyrsweo2nskxx7eds6y2bgm.ipfs.localhost:8080
    1. second order central difference $$ \frac{\partial \phi}{\partial x} = \frac{\phi{i+1} - \phi{i-1}}{2\Delta x} $$

      $$ \frac{\partial^2\phi}{\partial x^2} = \frac{\phi_{i+1} - 2\phi + \phi_{i-1}}{\Delta x^2} $$

  6. bafybeicq7ssvd6yyrdzgs4bpby23imx7vdxhb55w7hmt7zu7m2n6ybmnly.ipfs.localhost:8080 bafybeicq7ssvd6yyrdzgs4bpby23imx7vdxhb55w7hmt7zu7m2n6ybmnly.ipfs.localhost:8080
    1. STABILITY OF CRANK-NICOLSON

      稳定性

    2. So the local truncation error for Crank-Nicolsonformula is and the global truncation error

      local truncation error $$ O(\Delta t^3) $$ global truncation error $$ O(\Delta t^2) $$

    3. ACCURACY OF CRANK-NICOLSON

      精度

    4. Crank-Nicolson
      • Explicit Euler
      • Implicit Euler
      • Crank-Nicolson
    5. Crank-Nicolson formula

      $$ x_{n+1} = x_n + \frac{\Delta t}{2}\left[f(t_n,x_n) + f(t_{n+1}, x_{n+1}) \right] $$

  7. bafybeifdxtggnhokzsb6hg4ve3sijpewdbwc4fxo56mhc5e6ockfih6rvy.ipfs.localhost:8080 bafybeifdxtggnhokzsb6hg4ve3sijpewdbwc4fxo56mhc5e6ockfih6rvy.ipfs.localhost:8080
    1. 4th order Runge Kutta

      4th order Runge-Kutta $$ \begin{aligned} k_1 & = f(t_n, x_n) \ k_2 & = f\left(t_n + \frac{\Delta t}{2} , x_n + \frac{\Delta t}{2} k_1\right)\ k_3 & = f\left(t_n + \frac{\Delta t}{2} , x_n + \frac{\Delta t}{2} k_2\right)\ k_4 & = f\left(t_n + \Delta t, x_n + \Delta t k3\right)\ x{n+1} & = x_n + \left(\frac{1}{6}k_1 + \frac{1}{3}(k_2+k_3) + \frac{1}{6}k_4\right)\Delta t \end{aligned} $$

    2. 2nd order Runge Kutta

      2nd order Runge-Kutta $$ \begin{aligned} k_1 & = f(t_n, x_n) \ k_2 & = f(t_n + \Delta t , x_n + \Delta t k1)\ x{n+1} & = x_n + \left(\frac{1}{2}k_1 + \frac{1}{2}k_2\right)\Delta t \end{aligned} $$

    3. 2nd order Runge-Kutta $$ \begin{aligned} k_1 & = f(t_n, x_n) \ k_2 & = f(t_n + \Delta t , x_n + \Delta t k1)\ x{n+1} & = x_n + \left(\frac{1}{2}k_1 + \frac{1}{2}k_2\right)\Delta t \end{aligned} $$

    1. Derivedoperators

      $$ [a]\varphi \equiv \neg \langle a\rangle\neg \varphi $$

      $$ x\models \langle a\rangle\top \Leftrightarrow \exist_{x'} x\overset{a}{\to} x' \land x'\models \top $$

      $$ \begin{aligned} x\models [a]\perp & \Leftrightarrow \forall_{x'} x\overset{a}{\to} x' \Rightarrow x'\models\perp \\ & \Leftrightarrow x\overset{a}{\nrightarrow} \end{aligned} $$

    2. $$ [a]\varphi \equiv \neg \langle a\rangle\neg \varphi $$

    3. satisfaction

      $$ \models $$

  8. bafybeicq7ssvd6yyrdzgs4bpby23imx7vdxhb55w7hmt7zu7m2n6ybmnly.ipfs.localhost:8080 bafybeicq7ssvd6yyrdzgs4bpby23imx7vdxhb55w7hmt7zu7m2n6ybmnly.ipfs.localhost:8080
    1. approximate the first derivatives

      中心差分二阶导数

    2. source $$ f(x+h) = f(x) + f'(x)h + \frac1{2}f''(x)h^2 +\frac1{6}f'''(\xi_3)h^3,\f(x-h) = f(x) - f'(x)h + \frac1{2}f''(x)h^2 -\frac1{6}f'''(\xi'_3)h^3\ f'(x) \approx \frac{f(x+h)-f(x-h)}{2h} $$

    3. Numerical Methods for Engineers
  9. bafybeiakog6znbrgrydmhpruc5nzmoreo2gg7dwtpfvgxnelgbgcxuit3a.ipfs.localhost:8080 bafybeiakog6znbrgrydmhpruc5nzmoreo2gg7dwtpfvgxnelgbgcxuit3a.ipfs.localhost:8080
    1. A (2, 5)

      $$A(2,5) = A(1,A(2, 4)) = 2^{2^{(2^{16})}}$$

      $$\Longleftarrow A(2,4) = A(1, A(2,3)) =2^{(2^{16})}$$

      $$\begin{aligned} \Longleftarrow A(2,3) = A(1, A(2,2)) = 2^{16} \end{aligned} $$

      $$\begin{aligned} \Longleftarrow A(2,2) &= A(1, A(2,1)) \\ & = A(1, A(1, 2)) \\ & = A(1, 4) = 16 \end{aligned} $$

  10. bafybeiax3vr6i7wslj3n5rckyvavow3p2myxquup4cismrern5p6nxjapi.ipfs.localhost:8080 bafybeiax3vr6i7wslj3n5rckyvavow3p2myxquup4cismrern5p6nxjapi.ipfs.localhost:8080
    1. $$ \begin{align} \hat{\bar{x}}_k = {\color{red} F} \bar{x}_{k-1} \\ \hat{P}_k = {\color{red} F}P_{k-1}{\color{red} F^\intercal} + {\color{red} Q} \\ K = \hat{P}_k{\color{red} H^\intercal}({\color{red} H}\hat{P}_k{\color{red} H^\intercal} + {\color{red} R})^{-1}\\ \bar{x}_k = \hat{\bar{x}}_k + K(\bar{z}_k - {\color{red} H}\hat{\bar{x}}_k) \\ P_k = (I-K{\color{red} H})\hat{P}_k \end{align} $$

    2. Further, especially when getting into nonlinear filtering, if the state information is not perfect,but the uncertainty is set to 0 (or just too small a value) it might cause the filter to be unstable.

      unstable

    3. xk

      $$\hat{\bar{x}}_k$$

    1. incident to some vertex

      vertex cover

    Annotators

    1. Markov chain with the same boundary values.

      harmonic is unique

    2. This current is

      $$ \begin{aligned} i_a &= \sum_y(v_a-v_y)C_{ay} \\ & = v_a\sum_yC_{ay} - \sum_y v_yC_{ay} \\ & = C_a v_a - \sum_y v_y P_{ay} C_a \\ & = C_a (1 - \sum_y P_{ay} v_y) \end{aligned} $$

    3. flowing into

      the current is from outside source

  11. Apr 2021
    1. which stores the last operationfrom thesametransaction

      prevLSN

    2. status:

      事务的三种状态: 运行中, 提交中, 终止中

    3. a sequence of log records

      Log record 类型

      • UPDATE
      • COMMIT
      • ABORT
      • END
      • CLR
    4. how a database can abort a transaction

      终止事务的原因:

      • 死锁
      • 用户主动终止
      • 操作违反约束
      • 系统崩溃
    5. what inequality must hold
      1. 所有被写入磁盘的日志的序列号都 <= flushedLSN
      2. 日志被数据先写入磁盘
    6. prevLSN
      • flushedLSN 保存在内存
      • prevLSN 保存在 log record
      • pageLSN 保存在 data page
    7. crease by 10 each time

      为什么不是连续的?

    8. two rules
      1. 日志要在数据之前写入磁盘
      2. 当事务提交时所有日志必须写入磁盘
    9. Durability

      持久性

  12. Jun 2019
    1. The Strategy Pattern defines a family of algorithms, encapsulates each one, and makes them interchangeable. Strategy lets the algorithm vary independently from clients that use it.

      a behavioral pattern

    2. Favor composition over inheritance.

      composition vs inheritance

      • Document title: MCUXpresso SDK USB Stack User’s Guide
      • Document number: MCUXSDKUSBSUG
      • Document version: Rev. 9, December 2018

    Tags

    Annotators

    1. Full Speed USB connector (USB0)

      J3

      • title: LPCXpresso546x8/540xx/54S0xx Board User Manual
      • version: Rev. 2.1—7th January 2019

    Annotators

    1. splinters

      碎片

    2. block size

      include the header and padding

    Annotators

  13. May 2019
    1. The stator, or stationary part of the stepping motorholds multiple windings. The arrangement of thesewindings is the primary factor that distinguishesdifferent types of stepping motors from an electricalpoint of view.

      定子上的线圈排列是步进电机电气上的主要区分因素

    2. variable reluctance

      可变磁阻

    3. stator

      定子

    4. rotor

      转子

    5. Brushless

      无刷

    Annotators

    1. The ADC converts an analog input voltage to a 10-bit digital value through successive approximation.

      successive approximation

    2. The ADC contains a Sample and Hold circuit which ensures that the input voltage to the ADC is held at a constant level during conversion.

      Sample and Hold circuit.

    3. 0x08

      TWSR: a START has been trasmitted.

    Annotators

  14. Mar 2019
  15. Feb 2019
    1. any word beginning with an upper-case letter is a Prolog variable
    2. This is the way logical conjunction is expressed in Prolog (that is, the comma means and )
    3. the semicolon ; is the Prolog symbol for or

      how to express disjunction

  16. Oct 2018
    1. the potency of a substance in inhibiting a specific biological or biochemical function

      物质抑制某特定生物/生化功能的效力

    2. inhibitory concentration

      抑制浓度

    1. In certain databases the key values may be points in some multi-dimensional space

      what is the best data structure for such search problems?

  17. Sep 2018
    1. it is usual to use a suffix / followed by a number to indicate the predicate’s arity

      后缀 /

  18. people.inf.ethz.ch people.inf.ethz.ch
    1. 2.2.1 Pinhole Camera Model

      $$s\tilde{\mathbf{m}} = \mathbf{A}[\mathbf{R}\ \mathbf{t}]\tilde{M}$$

    2. 2.2.2 Absolute Conic

    1. the :- means implication, the , means conjunction, and the ; means disjunction
      • :-: means implication
      • ; : means conjunction
      • , : means disjunction
    1. This will introduce us to the three basic constructs in Prolog: facts, rules, and queries.

      facts, rules, queries

  19. Aug 2018
    1. network *net = make_network(sections->size - 1);

      网络层数由配置文件中的 section 数决定: net->n = n;

    2. get_network_output_layer
    3. net->outputs = out.outputs;

      网络的输出

    1. Enter a directory where you’d like to store your code and run: scrapy startproject tutorial

      创建一个Scrapy project

    2. we want the attribute href

      ::attr(href)

  20. Jul 2018
    1. How big is your cache block

      Cache block size: 2 (in words) = 8 (in bytes)

    2. How much data fits in the WHOLE cache

      Capacity: 8 words = 32 Bytes

    1. Your processor must provide the following outputs

      九个输出

    2. Your processor has 2 inputs

      两个输入: 指令 和 时钟

    1. The __thiscall calling convention is used on member functions and is the default calling convention used by C++ member functions that do not use variable arguments.

      成员函数使用 __thiscall 调用约定

    1. Qt add-ons
      • for specific purposes
    2. Qt essentials
      • general and useful
      • available on all supported platforms
    1. There are a few different options to run GUI applications inside a Docker container like using SSH with X11 forwarding, or VNC but the simplest one that I figured out was to share my X11 socket with the container and use it directly.
      docker run -ti --rm \
             -e DISPLAY=$DISPLAY \
             -v /tmp/.X11-unix:/tmp/.X11-unix \
             firefox
      
    1. 2/3" (~ 8.8 x 6.6 mm)

      海康 DS-2CD7A86F-IZ(S) 800万 2/3" CMOS ICR日夜型筒型网络摄像机<br> 镜头参数: 2.8~16mm @F1.4,水平视场角:23.8°~98.5°

      math.atan(8.8 / 2 / 2.8) * 180 / math.pi * 2
      
  21. Jun 2018
    1. Floating Point Calling Conventions

      浮点参数传递方式及返回值

    2. CPU Registers

      CPU寄存器

    3. The supported data types are as follows

      数据类型

    4. Comments

      注释语句

    5. Parameter Passing

      参数传递

    6. Floating Point Instructions

      浮点指令运算

    1. The idea of the numeric_limits<T> trait class is due to John Barton and Lee Nackman

      numeric_limits<T>

  22. May 2018
    1. 计算机图形显示和图象处理的算法<br>

      英文原版: Algorithms for Graphics and Image Processing <br> see here <br> 作者: Theo Pavlidis

    1. 中文翻译版为: <br> 计算机图形显示和图象处理的算法, 1987, 科学出版社

    2. 这本书涉及了许多图像处理中经典的算法, 包括:

      • 细化 Thinning
      • 边界追踪 Contour Tracing
      • 边界填充 Contour Filling?
    3. Algorithms for Graphics and Image Processing
    1. 机器人机构学的数学基础 - 丁靖军, 刘辛军, 丁希仑, 戴建生 编著 (1-50)

    2. 第1章 绪论

      1.1 机构学与机器人学的发展历史概述

      机构学广义上成为机构与机器科学 (Mechanism and Machine Science)

      • 第一阶段(古世纪--18世纪中叶): Aristotle, Problems of Machines
    1. 机器人机构学的数学基础 - 丁靖军, 刘辛军, 丁希仑, 戴建生 编著 (版权页, 前言页, 目录页)

    1. The chapter 2 (Multilayer Networks) gives a overview of the most prominent <s>convolutional network architectures</s> multilayer architectures.

    1. 49-50<br> George Polya<br>Most famous for his classical problem book (known as Polya-Szego), he is also revered as the godfather of combinatorics.

      L. J. Mordell and Gabor Szego<br>Speaking of Szego, here he is (right). Mordell was a great number theorist, known for, among other things, the deep conjecture (related to Fermat's last "theorem") that was proved by Falting (#579) in 1983.

      PT42

    1. 577-578<br> J. E. Taylor<br>Jean, another Council shot, works on minimal surfaces; she has been known to talk about soap bubbles, of course, and crystals too.

      R. A. Askey<br>I caught Dick during a Bloomington visit in March 1984. Hist specialty is special functions, such as ultraspherical polynomials and Jocobi polynomials; a part of his work was involved in de Branges' solution of the Bieberbach conjecture.

      PT315

    1.  Borodovsky  &  Ekisheva  (2006),

      Problems and Solutions in Biological Sequence Analysis

    2. What  is  the  probability  P(S)  that  this  sequence  S  was  generated  by  the  HMM  model?

      计算序列由模型生成的概率

    3. Viterbi  algorithm

      the probability of the most probable path ending in state \(k\) with observation \(i\) is

      $$ p_l(i,x) = e_l(i)\max_k(p_k(j, x-1)\cdot p_{kl}) $$

      or using the log of the probabilities $$ \ln p_l(i,x) = \ln e_l(i) + \max_k(\ln pk(j, x-1) + \ln p{kl}) $$

    4. HMM  :  Viterbi  algorithm  -­a  toy  example
  23. Apr 2018
    1. two cate-gories.

      基于深度学习的自然场景文字检测大致可分为两类:

      1. 将文字当为一般对象采用一般对象的检测范式, 对多方向文字处理有问题
      2. 分割出文字区域再进行复杂的后期处理
  24. Mar 2018
    1. a revolutionary technique(expression tem-plates,invented independently by Todd Veldhuizen-'' andDavid Vandevoorde") could be used to improve dramaticallythe runtime efficiency of high-level C++ code like sumlt.

      expression templates invented independently by Todd Veldhuizen and David Vandevoorde

    1. Beating the Abstraction Penalty in C++ Using Expression Templates,
    2. DisambiguatedGlommableExpressionTemplates

      Disambiguated Glommable Expression Templates, Computers in Physics 11, 263 (1997)

    3. Todd Veldhuizen - Techniques for Scientific C++ (RT542.pdf)

    4. Scienti candEngineeringC++

      Barton and Nackman, Scientific and Engineering C++

  25. eigen.tuxfamily.org eigen.tuxfamily.org
    1. MSVC (Visual Studio), 2010 and newer.

      vs2010 及以上版本

    2. Eigen is a pure template library defined in the headers

      纯模板库

    1. expres-sion templates (CIP 10:6, 1996 p. 552; CJP I 1 :3, 1997, p. 263)
      1. Beating the Abstraction Penalty in C++ Using Expression Templates, Computers in Physics 10, 552 (1996)
      2. Disambiguated Glommable Expression Templates, Computers in Physics 11, 263 (1997)
    2. Todd Veldhuizen, the co-discoverer of expres-sion templates (CIP 10:6, 1996 p. 552; CJP I 1 :3, 1997, p. 263), i now a graduate student at the Univer-sity of Waterloo.

      Todd Veldhuizen 创建Blitz++ 时是滑铁卢大学的一名研究生

    1. the checker board

      checker board classification example