Mars rover Opportunity is still silent because of the dust storm on Mars

Mars rover Opportunity is still silent because of the dust storm on Mars  
These two photos taken by Curiosity on May 21 (left) and June 17 (right) show how different the current level of illumination of Mars, in the atmosphere of which the dust storm rages, is from the normal situation.
 
 
On Mars for many weeks now raging dust storm , which covered almost the entire planet. Because of it, the Opportunity rover does not receive the necessary amount of sunlight, which is converted by photocells into electricity. The Rover has gone into sleep mode and will not be able to get out of it until the atmosphere clears itself of dust and the sun's rays reach the surface of Mars.
 
 
When th...
+ 0 -

String concatenation, or Patches bytecode

Not so long ago I read article on optimizing the performance of Java code - in particular, string concatenation. In it there was a raised question - why when using StringBuilder in the code under the cut the program runs slower than with the simple addition. In this case + = at compilation turn into calls StringBuilder.append ().
 
 
I immediately had a desire to understand the problem.
 
classmate. yegorf1 decided to understand why and how exactly this magic happens.
 
 

Oracle Java SE


 
The obvious solution is to compile the sources into bytecode, and then look at its contents...[/h]
+ 0 -

Optimizing the placement of virtual machines on servers

Optimizing the placement of virtual machines on serversSome time ago, one of my colleagues said that the place in DC is running out, there is nowhere to place the server, and the load is growing and it's unclear what to do, and probably will have to change all available servers to more powerful ones.
 
 
At that time I was busy with the task of drawing up optimal schedules, and I thought - what if using optimization algorithms to increase server utilization in DC? Hence the project was born, which I want to write about.
 
 
For the advanced, I will immediately say that in this article we will talk about bin packing, and the rest, who wants to learn ...
+ 0 -

Curves of the development of the programmer and a little about the effect of Dunning - Kruger

Curves of the development of the programmer and a little about the effect of Dunning - Kruger
 
 
There are two main ways of establishing top management in IT companies:
 
 
 
Managerial - when the project manager starts to manage other managers.
 
Tehnarskiy - when the developer starts to manage other developers and the number of personnel managed by him increases.
 
 
The first way is more natural, since it implies the development of the basic qualities of the manager as it grows. In fact, the manager remains the manager, only becomes a specialist of a higher level.
 
 
The second way is more long and does not guarantee success, because it is contrary to the essence of the introvert programmer...
+ 0 -

Bloomberg: hedge funds recognized the result of Brexit before others and earned billions of

Bloomberg: hedge funds recognized the result of Brexit before others and earned billions of
 
 
Image:
Unsplash

 
 
Bloomberg published story On the cooperation of hedge funds with organizers of British pre-election polls. Thanks to them, financial companies multiply their profits many times, being able to prepare for a situation in which, contrary to forecasts and the first calculated results, the British voted to withdraw from the European Union. In our material - the main facts of the investigation. The Black Swan ...
+ 0 -

City interface: tactile tiles on the sidewalks

For some time he lived in Copenhagen, and looked around. Once I looked at my feet, and found that the tiles were put on a special system.
 
First tried to understand - why in the whole city so often shift the tiles on the sidewalks? It turned out that everything is done for the blind.
 
I want to show you how the city of Copenhagen makes the life of the blind easier with tiles.
 
City interface: tactile tiles on the sidewalks
 
Guide tile
 
Pay attention to the paths lined with a wide tile.
 
 
They share a narrow strip of small tiles, which can be felt even in shoes with ...
+ 0 -

Amazon plans to land on the moon by 2023

Amazon plans to land on the moon by 2023  
 
On the moon, it seems, everyone wants now: Russians, Americans, Chinese, Hindus and even Pakistan. Own programs for the development of the moon are developed as state organizations that receive money from their own country's budget, as well as private ones. As for the latter, the other day the regiment arrived - Luna decided to tackle and Jeff Bezos.
 
 
And we are not talking about lunokhods, but about guided mission , which Blue Origin is planning to send to the natural Earth satellite. The ...
+ 0 -

Synchronization of wallets with Bitcoin network

Synchronization of wallets with Bitcoin networkLet's talk about synchronization of digital wallets with Bitcoin network. Let's designate the basic approaches, the principles of their work and complexity. The material can be useful not only to developers, but also to ordinary users for acquaintance with features of the device of digital purses and aspects of safe work with purses.
 
" is recorded. Synchronization of wallets with Bitcoin network ".
 
 

The basic functions of the purse are


 
Let's start with the basic functionality of the digital wallet:
 
 
 
backup of private keys;
 
acceptance of payments;
 
balance display;
 
display ...[/h]
+ 0 -

What is behind the Defold and with what it is eaten?

What is behind the Defold and with what it is eaten?

 
This is a small analysis of the game engine Defold in a practical example (under Andoid), as well as a little bit of subjective criticism and praise, well, in general review. Who is interested in learning more about this engine, there is one interview, read . Information about Defold in the network is small, so this will contribute to a very small piggy bank.
 
site editor Defold version 2 (1 is no longer supported), there we create our own project and download. The project is then stored on the site, or locally (if we are afraid that the cunning Defold will spy). Next, open through the ...
+ 0 -