• Laravel excel 3.0 document


    Basics The simplest export method is to create a custom export class. Here we use invoice export as an example stayApp/ExportsCreate nextInvoicesExportclass namespace App\Exports; use Maatwebsite\Excel\Concerns\FromCollection; class InvoicesExport implements FromCollection { public function collection() { return Invoice::all(); } } In the controller, you can use the following methods to download public function export() { return […]

  • [system architecture] understand the shengteng Da Vinci architecture computing unit


      Welcome to my official account, to get more notes.   O_o   >_<   o_O   O_o   ~_~   o_O This paper explains the architecture and computing principle of computing unit in shengteng Da Vinci architecture in detail. 1. Da Vinci Architecture Overview Da Vinci architecture is a “domain specific architecture” (DSA) chip. The […]

  • Audio and video data processing (I) – H264 / AVC video stream analysis


    1、 H264 overview H264 is the tenth part of MPEG-4. It is a video codec standard jointly proposed by ITU-T and ISO / IEC. This standard is usually called h.264/avc. H264 coding is a mainstream coding method. This paper mainly analyzes H264 video bitstream from the perspective of data processing. 2、 H264 bitstream structure H264 […]

  • docker-compose


    docker-compose https://docs.docker.com/compose/ Two important concepts:Service: an application container can actually contain several container instances running the same image Project: a complete business unit composed of a group of associated application containers, which is located in docker-compose.com YML file definition =====pre=====install docker vi /etc/sysctl.conf net.ipv4.ip_forward = 1 =====install=====curl -L “https://github.com/docker/compose/releases/download/1.28.5/docker-compose-$(uname -s)-$(uname -m)” -o /usr/local/bin/docker-composechmod +x /usr/local/bin/docker-composeln […]

  • Learn D3 getting started document: Data


    Introduction FollowLearn D3: By ExampleThe third article is only an English translation. The modifiable code is replaced by static pictures. If you want real-time interaction, please read the original text. Original text:Learn D3: Data Version: Published Mar 24, 2020 Origin My GitHub text There are several methods on observableget data。 But since we’re just getting […]

  • HBase learning 1 (basic introduction)


    1、 What is HBase? HBase is a distributed, column oriented open source database. This technology comes from the Google paper “BigTable: a distributed storage system of structured data” written by Fay Chang. Just as BigTable makes use of the distributed data storage provided by Google file system, HBase provides capabilities similar to BigTable on Hadoop. […]

  • X86 architecture (CPU, bus, memory)


    It is hereby explained that Liu Chao’sOn Linux operating systemIt is an important reference. Most of the content and all the pictures of this article come from this column. 00. Working mode of computer key word: CPU, bus, memory, other devicesunderstand: the computer only performs data operation through the CPU, saves the intermediate results to […]

  • Linux command final


    System foundation relatedUse the environment variable of the root user to switch to the root user su-Displays the current working path PWDDisplays the current system default language and keyboard layout localectlDisplays all languages that can be supported in the system, localectl list localesThe default language of the configuration system is Chinese localectl set locale lang […]

  • Centos7 housekeeper systemctl


    Blog reference http://www.178linux.com/48343 http://www.178linux.com/48674 http://www.178linux.com/48563 http://www.jinbuguo.com/systemd/index.html Introduction to SYSTEMd SYSTEMd was developed by Lennart poetering, an employee of red hat company. SYSTEMd is the latest initialization system (init) in Linux system. Its main design purpose is to overcome the inherent shortcomings of sys V and improve the startup speed of the system. SYSTEMd and upstart […]

  • Machine learning from 0 – neural network recognition of handwritten characters!


    1、 Problem description Today, Denglong shared with you the method of using feedforward neural network to recognize 10 types of handwritten characters. Students who don’t know the basics of neural network can check my last article:Machine learning from 0 – Fundamentals of neural networks Our goal is to use a trained neural network to predict […]

  • Training neural networks for machine learning: Best Practices


    This part introduces the failure cases of back propagation algorithm and the common methods of regularized neural network. Failure cases Many common situations will lead to the error of back propagation algorithm. Gradient disappearance The gradient of the lower layer (closer to the input) may become very small. In the depth network, the calculation of […]

  • Multi Center disaster recovery practice: how to realize real multi activity in different places?


    Introduction:In the realization of multi live in different places, the core technology to solve the real multi live in different places is that the data can be synchronized in two directions between three or more centers. Based on the three center and cross overseas scenario, this paper shares a multi center disaster recovery architecture and […]