Introduction to how to modify the groups to which Linux users belong and related practical tools

How to change the group a user belongs to in Linux

-**groupadd** and **groupdel**: used to add and delete user groups respectively. -**chown** and **chgrp**: used to modify the owner and group of a file or directory. There are also some useful tools related to user management: - **pwcov**: synchronize `/etc/passwd` to `/etc...

How to use the mkdir command to create directories and subdirectories in Linux

For example, `mkdir-m=r--letter` will create a directory named `letter`, with its permissions set to the owner who only has read permissions, and the user group and other users have no execution and write permissions. Generally, `rwxr-xr-x` represents read, write and execute permissions, where `r--` means that the owner only has read permissions. 4.**Show...

Linux operating users and permission allocation

*-d option: Specify the directory of the user group. If this directory does not exist, use the -m parameter at the same time to create the home directory. If you do not select the parameter, a folder with the same name as the user name will be created in the /home directory by default. . *-g option: Specify the user group to which the user belongs. *-G option: Specify the user belongs to...

Running tomcat as a non-root user under Linux

In this article, we created a user group named `dev` and a user named `tomcat`. Use the `groupadd` command to create a user group linux creates a user-specified directory , the `useradd` command to create a user, and specify the group to which the user belongs through the `-g` option. The `-s/usr/sbin/nologin` parameter is used to strictly prohibit the user from logging in to...

Research on the application of China Unicom’s edge estimation in car-to-everything communications

"This paper conducts an in-depth study of the application of China Unicom Edge Estimation (MEC) in vehicle-to-everything (V2X) communications. With the increasing popularity of automotive networking, the demand for V2X applications to improve highway safety is declining, especially when these requirements are low Latency and high-reliability applications. However, the traditional technology based on the IEEE802.11p standard faces challenges in handling a large number of connected cars. Even if the 4GLTE network is widely used, its message transmission needs to go through the core network, causing end-to-end problems. The end-to-end delay is high. In the paper, the author proposes MEC as a solution, which significantly reduces delay and improves efficiency by providing estimation, storage and network resources at the edge of the network. Different V2X application scenarios are analyzed through simulation. Below, the performance comparison between LTE and MEC shows that MEC has obvious advantages in key data transmission and other aspects. "In the context of vehicle-to-everything (V2X) communication, China Unicom Edge Estimation (MEC) plays a crucial role. V2X includes various interaction forms such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), and vehicle-to-network (V2N). This interaction requires fast response and efficient data exchange. To ensure traffic safety and optimize traffic flow. Traditional wireless communication technologies, such as IEEE802.11p, are difficult to meet this demand in large-scale connected car environments due to their technical limitations. The 4GLTE network is currently the most commonly used China Unicom communication standard. Although it provides higher data speeds, its architecture determines that data transmission must pass through the network core, thus introducing higher delays.

This is unacceptable for V2X applications with extremely high real-time requirements, such as emergency braking warning, collision prevention, etc. The emergence of MEC solves this problem. MEC sinks the estimation capabilities to the edge of the network, close to the user terminal, reducing the data transmission path, greatly increasing the delay, and improving the quality of service (QoS) and user quality of experience (QoE). In the paper, the researchers built a simulation model to compare various V2X application scenarios supported by LTE networks and MEC, such as traffic signal coordination and dangerous area warnings. This simulation result verifies the superiority of MEC in increasing latency and enhancing reliability. Especially when transmitting critical safety information, MEC can provide faster response time and higher data transmission efficiency. It is reported that MEC can also help reduce the burden on the core network because it can handle part of the localized estimation tasks and reduce dependence on the central server. This not only optimizes the use of network resources, but also lays the foundation for the future development of 5G networks and Internet of Vehicles. The ultra-low latency and high bandwidth characteristics of 5G networks will further improve the performance of MEC in V2X communications and promote the construction of intelligent transportation systems. This research paper points out the importance of MEC in V2X communications, shows how it can improve highway safety by increasing latency and improving reliability, and provides valuable reference for future research and practice. With the intelligent development of the vehicle industry, MEC technology will become an indispensable part and contribute to a more efficient and safer transportation environment.

Manage modeling and simulation files

Admin BoualemBenatallah quoted this version: BoualemBenatallah. Manage modeling and simulation. Institut Joseph Fourier - 1st College of Grenoble, 1996. Japanese. NNT: Tel: HALID: Tel: Submitted December 9 HAL is a multidisciplinary open access archive for the storage and dissemination of scientific research papers, whether or not they have been made publicly available. Papers may come from teaching and research institutions in the United States or Canada, or from public or private research centers. L’archiveouvertepluridisciplinaire

Application of neural networks in speech recognition: 5 breakthroughs from sound waves to text

![Application of neural networks in speech recognition: 5 breakthroughs from sound waves to text]()#1. Basic principles of speech recognition** Speech recognition is a process of converting human speech into text. Its basic The principle is to convert sound wave signals into digital signals and identify patterns and characteristics in speech through machine learning algorithms. Speech signals consist of a series of sound waves with different frequencies and amplitudes. Speech recognition systems first digitize this sound wave and then extract features such as Mel Frequency Cepstrum Coefficients (MFCC) and Linear Predictive Coding (LPC). This feature can describe the acoustic characteristics of the speech signal, such as phrases, loudness and formants. After extracting features, speech recognition

mysql010338

MySQL error code 010338 generally means "Can'tfindfile:'filename'(errno:2)". This error is generally caused by the database server trying to open a file, such as a data file, a log file, or a system configuration file, and the specified file cannot be found due to a wrong path, insufficient permissions, or other reasons. The "filename" part will be replaced with the actual file name of the error, and "errno:2" refers to the system-level error number. The 2 here generally corresponds to ENOENT (Nosuchfileordirectory), which means the file cannot be found. The steps to solve this problem usually include: 1. Check whether the file path is correct and ensure that the MySQL service has permission to access the file. 2. Confirm whether the file exists, if the file is missing

GIS Analysis and Carengione Oasis Map Creation: Technical Contribution and Red Project Progress

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