We are looking for cycles on the Lorenz attractor in the Maxima package

We are looking for cycles on the Lorenz attractor in the Maxima package
 
 
This topic continues a series of my articles on Habré devoted to the study of the Lorenz attractor.
 
 
Part 1. A critical look at the Lorenz attractor
 
Part 2. The dynamic Lorentz system and the computational experiment
 
Part 3. On the existence of periodic solutions in the Lorentz system
 
Part 4. Three cycles in the Lorenz attractor
 
 
Thus, consider the nonlinear system of differential equations introduced by Edward Lorentz in 1963:
 

where
 

classical ...
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Poll from Veeam Academy. Do you want to go through C # in the summer?

You can not go on vacation: is there a summer semester from Veeam Academy?
 
 
This summer Veeam Academy is going to launch another intensive programming in C #. To find out your opinion about how much education is relevant in the summer, at the end of the article we put a vote. And if you do not already know what Veeam Academy is, we'll be happy to tell you. In short: Veeam Academy - This is a free evening course in C # for beginner programmers. Graduates have a real chance to work in the group of companies Veeam Software. More - under the cut. ...
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DevConf: promising databases for highload

DevConf 2018 already next week! Last year Yury Nasretdinov conducted an interesting survey of promising data storage systems for highload. Video with the report is available at page of the report . And for habra-readers I offer a brief retelling.
 
 
DevConf: promising databases for highload In the beginning I'll tell you how to approach the choice of technology for a highload project.
 
 
 
First of all, there must be an understanding of how it works. Not only strong, but also weak points.
 
Knowing how to monitor and backup. Without good tools for this, this technology is early to use in production.
 
Sooner or later the systems ...
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Messenger problems: disappearing messages in Signal for Mac are not permanently deleted

Messenger problems: disappearing messages in Signal for Mac are not permanently deleted
 
 
The researcher of information security Alec Muffett (Alec Muffett)
found
the ability to restore vanishing messages in the Mac version of the secure Signal messenger. As a result, sensitive user information may be at risk. I was able to understand in the reasons for the incorrect work of the messenger. According to him, macOS creates copies of disappearing messages in a special user-accessible database in the Notification Center of the operating system - only a part of them is copied for long messages. From this source, they can be restored at any time after the message has been deleted from ...
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Patch Tuesday: critical patches that you might miss

We hope that the next day off in the middle of the week you did not relax and you carefully followed the "Tuesday of updates", which actually begins at 9-10 in Moscow. If the Victory Parade and the trip to the dacha knocked you out of the working rhythm a little, then welcome to the cat. Vendors rolled out several important patches that cover really serious vulnerabilities, so we recommend that you pay attention.
 
 
Patch Tuesday: critical patches that you might miss
 
 
The name Patch Tuesday came up with in Microsoft, so we'll start with them.
 
 
Microsoft Exchange immediately eliminated 5 vulnerabilities, one of which - ...
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What's new in PostgreSQL 11: improvements in casting

What's new in PostgreSQL 11: improvements in casting  
 
Continuing the theme of the new features of the upcoming release of PostgreSQL 11 (the previous posts: Times , two , tree ), I would like to tell you about one small but important change. Change this applies to casting some types in others. And, of course, it concerns JSONB, because in PostgresPro we love it very much! patch c0cbe00f :
 
 
commit c0cbe00fee6d0a5e0ec72c6d68a035e674edc4cc
 
Author: Teodor Sigaev
 
Date: Thu Mar ???:33:??? ...
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DevOps Moscow meetup: Monitoring

May 16 we invite engineers to the next Mitap of the DevOps Moscow community to Avito's office. The second meeting will be devoted to monitoring after a long break. In the program - reports on both the monitoring toolkit and the incident-management in general. Representatives Avito, Okmeter.io and Badoo will perform. Register for a meeting and invite colleagues. Under the cut - abstracts of speeches, links to the registration and video transmission of mitapa.
 
DevOps Moscow meetup: Monitoring registration is required ...
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Segmentation of tomographic data

Segmentation of tomographic data  
 

Why does it need


 
What is the tomographic study for? In most cases, for the sake of medical diagnosis, sometimes for scientific purposes. The purpose of medical diagnostics is to reveal a pathology, or to obtain additional information about it, or to make sure that it does not exist. How is this achieved? In most cases, by sequential manual analysis of slices generated by a tomograph. Often this is enough. But in some cases, it is impossible to obtain sufficient information only on the basis of the analysis of flat sections, or the picture is incomplete: for example, when searching for vascular ...[/h]
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Security of web applications: fight against oneself, or draw a line of adequacy

Security of web applications: fight against oneself, or draw a line of adequacy  
 
How secure is the application? For some, this question does not make sense. "As much as possible." The safer, the better. " But this is not an exhaustive answer. And it does not help to formulate a security policy in the project. Moreover, if we only adhere to this directive ("the more security, the better"), we can render a disservice to ourselves. Why? The answer is under the cut. https://doc.cuba-platform.com/manual-6.8-ru/roles.html ) And the access groups ( https: //doc.cuba- platform.com/manual-6.8-ru/groups.html ...
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Basics of optimizing the game code

Basics of optimizing the game code

 
Many beginner indie developers are too late to think about code optimization. It is given to the engines or frameworks or is considered as a "complex" technique that is inaccessible to their understanding. However, there are optimization methods that can be implemented in a simpler way, allowing the code to work more efficiently on more systems. Let's start with the very basics of code optimization.
 
 

Optimization for the sake of players and their own mental health


 
Quite often, indie developers imitate methods of optimization of large companies. This is not always a bad thing, but the ...[/h]
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