Modeling Dynamic Systems: How does the Moon move?

Modeling Dynamic Systems: How does the Moon move? The bright memory of my teacher - the first dean of the Physics and Mathematics Faculty of the Novocherkassk Polytechnic Institute, the head of the department "Theoretical Mechanics" Alexander N. Cabelkova
 
 

Introduction


 
 
August, summer is coming to an end. The people furiously jerked to the seas, but it is not surprising - the season itself. And on the habra, meanwhile, In a violent color, pseudoscience disintegrates and smells. . If we talk about the topic of this issue of "Modeling ", then we will combine business with pleasure - we will continue the promised cycle and quite ...[/h]
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We are writing a Linux kernel module: GPIO with IRQ support

Habr, greetings!
 
 
This article is devoted to the development of GPIO (General-Purpose Input /Output) of the Linux kernel module. As in the previous article we implement the basic structure of the GPIO driver with interrupt support (IRQ: Interrupt Request).
 
 
We are writing a Linux kernel module: GPIO with IRQ support  
here .
 
 

Step One


 
First, let's get acquainted with the principle of GPIO driver interaction through the user console.
 
Using a small bash script, create /sysfs controls for each GPIO. To do this, enter the following script in the command line:
 
 
for i in {248255}; do echo $ i> /sys /class /gpio /export; ...[/h]
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How effective is the virtual file system procfs and whether it can be optimized for

How effective is the virtual file system procfs and whether it can be optimized forThe proc file system (hereinafter simply procfs) is a virtual file system that provides information about processes. It is a "perfect" example of the interfaces of the following "everything is a file" paradigm. Procfs was developed a long time ago: at a time when servers on average served several dozen processes, when opening a file and subtracting information about the process was not a problem. However, time does not stand still, and now servers serve hundreds of thousands, or even more processes at the same time. In this context, the idea of ​​"opening a file for each process to subtract the ...
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Basics of working with futés

Basics of working with futés<{full}>
Futex (futex - short for Fast Userspace mutex) is a mechanism proposed by Linux developers from IBM in 2002 and included in the kernel at the end of 2003. The main idea was to provide a more efficient way to synchronize user threads with a minimal number of calls to the OS kernel.
 
 
In this article, we will review the futures, try to understand the principles of their operation, and also use them as bricks to build higher-level (and familiar) synchronization objects.
 
 
An important point: futexes are a fairly low-level tool, it's worth using it directly when developing fundamental libraries...
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How to play a roommate

How to play a roommate

From the translator


 
Student Tufts University tells how he tucked up his roommate. He even pinned me when he started his story with the fact that they have a 4K-TV in their dorm.
 
 

Introduction


 
Before I talk about how to bring the unfortunate Logan, I must explain the device of the media system in our room. Soon you will understand why.
 
 
Logan, if you're reading this, I hope you're more amused than not.
 
 

Disposition


 
We have a computer with a desktop Ubuntu, connected to a TV set. It acts as a media server. Since he still needs a permanent Internet connection...[/h][/h][/h]
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How I standard C ++ library wrote 11 or why boost is so terrible. Chapter 4.2.

How I standard C ++ library wrote 11 or why boost is so terrible. Chapter 4.2.

The summary of the previous parts


 
Because of the limitations on the ability to use the C ++ 11 compilers and the non-alternative to boost, there was a desire to write your own implementation of the standard C ++ 11 library on top of the C ++ 98 /C ++ 03 library supplied with the compiler.
 
 
were implemented. static_assert , noexcept , countof , as well as after reviewing all nonstandard defenses and compiler features, information has appeared on the functionality that is supported by the current compiler. The implementation of is included. nullptr , which is selected at ...[/h]
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Brain Trainer Qt (Learning to count in your mind or a weekend project)

I came across positions where the topic of effective account in the mind
was very vigorously discussed.  
One is , Two
 
The topic was interesting and I started looking for programs and services for training
 
 
Soon came the realization that it's faster to write your own application, under your own desks and with buttons where it's convenient for me, + the perspective of transferring to your favorite Windows Phone
 
 
For those who are interested to see /criticize - welcome to cat
 
Brain Trainer Qt (Learning to count in your mind or a weekend project)  
...
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Public Key Infrastructure: GnuPG /SMIME and PKCS # 11 tokens with support for Russian cryptography

 
Public Key Infrastructure: GnuPG /SMIME and PKCS # 11 tokens with support for Russian cryptography The hour "Ч" inexorably approaches: "the use of the signature scheme of GOST R ???-2001 for the formation of a signature after December 3? 2018 is not allowed!". And finally, on July 1? 2018 at site The federal e-government situation center appeared The notice on the commencement of the issuance of certificates for the verification of electronic signatures of the subordinate certifying centers at the head certification center in accordance with GOST R ???-2012. However, all the same it is not clear when the issue of old certificates will stop. But "the process has gone" and it pleases. ...
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Containers for adults: A practical guide to terminology (Part 02)

There are many container building templates. A container is just an executable version of its own image. Therefore, the way a container is constructed is closely related to how it is run.
 
 
Some container images work fine without any special privileges, others necessarily require root privileges. And the same image /container can combine several templates of construction and usage scenarios at once.
 
 
Containers for adults: A practical guide to terminology (Part 02)
 
 
Below we will consider the most typical scenarios for using containers.
 
 
(For an introduction to the terminology of containers, see of ...
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How I standard C ++ library wrote 11 or why boost is so terrible. Chapter 4.1

How I standard C ++ library wrote 11 or why boost is so terrible. Chapter 4.1

The summary of the previous parts


 
Because of the limitations on the ability to use C ++ 11 compilers and the non-alternative boost, there was a desire to write your own implementation of the standard C ++ 11 library on top of the C ++ 98 /C ++ 03 library delivered with the compiler.
 
 
were realized. static_assert , noexcept , countof , as well as after reviewing all nonstandard defenses and compiler features, information has appeared on the functionality that is supported by the current compiler. The implementation of is included. nullptr , which is selected at the compilation ...[/h]
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