Kubernetes Redis cluster with 3 master and 3 slave. Native Redis cluster is deployed on 3 servers. Each server hold one master and one slave. The conclusion is the kubernetes cluster is around 30% slower than native cluster. This is understandable since are a lot layers in kubernetes (container, kube dns…), but the benefit is …
Tensorflow record 1. Download Tensorflow 2. Create a simple model
|
1 |
https://www.tensorflow.org/tutorials/keras/save_and_restore_models |
3. Training The primary use case is to automatically save checkpoints during and at the end of training. This way you can use a trained model without having to retrain it, or pick-up training where you left of—in case the training process was interrupted. …
1.Quick found Data structure. • Integer array id[] of size N. • Interpretation: p and q are connected if they have the same id. Find Check if p and q have the same id. Time complexity: O(1) Union To merge components containing p and q, change all entries with id[p] to id[q]. Time complexity: O(N) …
Kafka is a distributed publish-subscribe messaging system. Publish-subscribe refers to a pattern of communication in distributed systems where the producers/publishers of data produce data categorized in different classes without any knowledge of how the data will be used by the subscribers. The consumers/subscribers can express interest in specific classes of data and receive only those …
https://www.cnblogs.com/qiuyong/p/6791720.html?utm_source=itdadao&utm_medium=referral
ARIMA, Autoregressive Integrated Moving Average Model
ARIMA(p,d,q)
Advantage: Easy.
Disadvantage:
1. Time series or after differencing must be stationary.
2. Only linear relationship.
stationary means now trend, no seasonality.
p–lags Auto-Regressive
d–n differ can be stationary. Integrated
q–lags of error Moving Average
1.synchronized & asynchronized
To share final variable in multiple threads, must use synchronized or volatile.
2. mutual exclusion or visibility
mutual exclusion: only one thread can hold a lock at a time.
visibility: make sure the later thread can see the former thread changes to data.
3.Atom
Atom operation might not be thread safe.
thread can save duplicates of variable in itself memory.
Eight Queen Problem
This idea is from https://www.cnblogs.com/bigmoyan/p/4521683.html. It greatly reduces the space complexity compare to any 2D array solution.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 |
public class EightQueen { // layer int n = 8; int[] r = new int[n]; int count = 0; public void queen(int row) { if (row == n) { count++; return; } for (int i = 0; i < n; i++) { r[row] = i; if (isValid(row)) { queen(row + 1); } } } private boolean isValid(int row) { for (int i = 0; i < row; i++) { if (r[row] == r[i] || row - r[row] == i - r[i] || row + r[row] == i + r[i]) { return false; } } return true; } public static void main(String[] args) { EightQueen eq=new EightQueen(); eq.queen(0); System.out.println(eq.count); } } |
Convolution: 180 degree kernel before operation.
Cross-correlation problem, and need to normalized it.
Harris-Laplace
SIFT
http://blog.csdn.net/zddblog/article/details/7521424
1.ALLOWED_HOSTS
2.SECURE_HSTS_SECONDS=3600
3.SECURE_HSTS_INCLUDE_SUBDOMAINS=True
4.SECURE_CONTENT_TYPE_NOSNIFF=True
5.SECURE_BROWSER_XSS_FILTER=True
6.SECURE_SSL_REDIRECT=True
7.SESSION_COOKIE_SECURE=True
8.CSRF_COOKIE_SECURE=True
9.X_FRAME_OPTIONS=’DENY’
10.SECURE_HSTS_PRELOAD=True
http://image.sciencenet.cn/olddata/kexue.com.cn/upload/blog/file/2010/9/2010929122517964628.pdf
1.
Use Integer.parseInt instead of Integer.valueOf
Static method, less objects
2.
Use String.valueOf instead of Integer.toString
or check null by ourselves
3.
Use StringBuffer instead of s=s+””
Static method, less objects