Hello Habr! Now that is summer vacation season. Many of you will take a flight to a place far from your everyday routine at home. Before this hot vacation season starts, we should discuss an interesting and useful method on how to save money using a VPN.

One of the easiest ways to see the value in this is looking at car rentals while on vacation.

If you were asked to draw a picture of several people in ski gear, standing in the snow, chances are you’d start with an outline of three or four people reasonably positioned in the center of the canvas, then sketch in the skis under their feet. Though it was not specified, you might decide to add a backpack to each of the skiers to jibe with expectations of what skiers would be sporting. Finally, you’d carefully fill in the details, perhaps painting their clothes blue, scarves pink, all against a white background, rendering these people more realistic and ensuring that their surroundings match the description. Finally, to make the scene more vivid, you might even sketch in some brown stones protruding through the snow to suggest that these skiers are in the mountains.

Now there’s a bot that can do all that.

Uber, as we know, operates only in 650 cities and remains the best among all taxi apps. But have you ever imagined about other cities and their demand for taxi applications? If you did, you would have certainly come across a few regional apps like Ola, Didi Chuxing, Japan Taxi, etc. These apps are focused on fulfilling the demands of locals; and in that way, they have succeeded and generated revenue tremendously. If you search for the reason behind the success of these apps, it inevitably ends up in the kind of service it provides its customers. So, it all depends on how well you bestow your service (whether you focus regionally or globally).

Alexandr Epaneshnikov, a 19-year-old Russian student who is legally blind, recently decided he wanted to be more independent by commuting on his own and relying less on his mom for rides to school. It meant taking a streetcar to a subway to his high school in Moscow, a 30-minute trip that Epaneshnikov assuredly navigates with a cane and Moovit, an urban mobility app optimized for screen readers.

Before reading this article, it is recommended to read the previous one: Audio over Bluetooth: most detailed information about profiles, codecs, and devices / по-русски

Some wireless headphone users note low sound quality and lack of high frequencies when using the standard Bluetooth SBC codec, which is supported by all headphones and other Bluetooth audio devices. A common recommendation to get better sound quality is to buy devices and headphones with aptX or LDAC codecs support. These codecs require licensing fees, that's why devices with them are more expensive.

It turns out that the low quality of SBC is caused by artificial limitations of all current Bluetooth stacks and headphones' configuration, and this limitation can be circumvented on any existing device with software modification only.

This article is also available in Russian / Эта статья также доступна на русском языке

The mass market of smartphones without the 3.5 mm audio jack changed headphones industry, wireless Bluetooth headphones have become the main way to listen to music and communicate in headset mode for many users.
Bluetooth device manufacturers rarely disclose detailed product specifications, and Bluetooth audio articles on the Internet are contradictory and sometimes incorrect. They do not tell about all the features, and often publish the same false information.
Let's try to understand the protocol, the capabilities of Bluetooth stacks, headphones and speakers, Bluetooth codecs for music and speech, find out what affects the quality of the transmitted audio and the delay, learn how to capture and decode information about supported codecs and other device features.

TL;DR:

• SBC codec is OK
• Headphones have their own per-codec equalizer and post processing configuration
• aptX is not as good as the advertisements say
• LDAC is a marketing fluff
• Voice audio quality is still low
• Browsers are able to execute audio encoders compiled to WebAssembly from C using emscripten, and they won't even lag.

Hello, dear Habr users! This article is about Web 3.0 — the decentralized Internet. Web 3.0 introduces the concept of decentralization as the foundation of the modern Internet. Many computer systems and networks require security and decentralization features to meet their needs. A distributed registry using blockchain technology provides efficient solutions for decentralization.

RUVDS and Habr continue the series of interviews with interesting people in IT field. Last time we talked to Richard «Levelord» Gray, level designer of popular games Duke Nukem, American McGee’s Alice, Heavy Metal F.A.K.K.2, SiN, Serious Sam, author of well-known «You’re not supposed to be here» phrase.

Today we welcome Randall Steward «Randy» Pitchford II, president, CEO and co-founder of Gearbox Software video game development company.

Randy started in 3D Realms where contributed to Duke Nukem 3D Atomic Edition and Shadow Warrior. Then he founded Gearbox Software and made Half-Life: Opposing Force, which won D.I.C.E in 2000. Other Gearbox titles include Half-Life: Blue Shift, Half-Life: Decay, Counter-Strike: Condition Zero, James Bond 007: Nightfire, Tony Hawk's Pro Skater 3, Halo: Combat Evolved and of course Borderlands.

The interview team also includes editor of Habr Nikolay Zemlyanskiy, Richard «Levelord» Gray, Randy’s wife Kristy Pitchford and Randy’s son Randy Jr.

We’re excited to announce the preview availability of the new Azure IoT Edge Tools Extension (Preview) for Visual Studio 2019. The extension provides a rich set of functionalities to support development of IoT Edge solutions with Visual Studio 2019:

The role of project management is becoming more and more relevant no matter in which area or industry it is implemented. In fact, it balances all project processes and steps and helps project teams meet their goals and objectives.

Project management helps to reach goals faster, cheaper and avoid risks thereby contributing greatly to business strategy execution. More companies cannot imagine their performance success without project management as one of the key business competencies. Since this competence is actively developing, professional project management software is also evolving with it in the same way.

The animation is at the heart of mobile app User experience (UX). Truth be told, energized changes quietly impart an assortment of messages and show the client the best way to explore through the mobile app by just coordinating the client's consideration.

For instance, liveliness can signify a connection between shared components. They can likewise be fundamental in demonstrating the progression between two states or direct the client's thoughtfulness regarding a suggestion to take action catch.

Such powerful development in mobile apps is dependably a utilitarian segment as opposed to adornments like structure components. Thus, movement in the UX configuration ought to be approached from the earliest starting point when the group designs the client's voyage.

At the point when the impact and ease of use of enlivened components are broken down during the QA testing stage, these changes can likewise be wiped out on the off chance that they neglect to convey a positive effect.

Vivified connections can make consistent cooperative energy between screens or realize a snapshot of progress. For instance, these activities can be any or the majority of the accompanying:

• Check the container
• Explore to another page
• Open settings
• Give framework status
• Communicate something specific

The above is only a glimpse of something larger. So as we quickly approach the finish of 2018, we should investigate the three most blazing mobile app movement inclines that are upgrading UX no matter how you look at it.

What is 3D printing?

3D printing is a new way of manufacturing solid objects based on the principle of discrete-stacking.
With the evolution of the trend, 3D printing has become a way to promote smart manufacturing, flexible manufacturing and green manufacturing. It can realize the integrated formation of complex structures that are difficult to process or even cannot be processed by traditional manufacturing technologies, greatly enhancing the process realization capability. Subversive advancement in equipment design and manufacturing.

From the past used to manufacture models, and now gradually realize the direct manufacturing of products, 3D printing manufacturing technology is developing towards the integration of “design-material-manufacturing”. According to research, the size of the world 3D printing market in 2017 was 3.86 billion US dollars. In 2018, the scale of China's 3D printing market was as high as 7.75 billion US dollars, which has more than doubled in two years. From behind the scenes to the forefront of the industry, the development of the 3D printing industry has moved from the concept introduction period to the rapid development period, all thanks to: "application." Members of the World 3D Printing Association have said:

“When 3D printing technology goes out of the lab,
Its development motivation lies in its application”

The San Juan Math, Science, and Technology center in Puerto Rico is using game-based learning to pave the way for a new level of engagement among their students. The institution is part of San Juan’s municipal education system and is recognized by Microsoft alongside a global community of other schools engaged in K-12 education transformation. The school decided to integrate Minecraft: Education Edition into their curriculum and have seen exciting results in STEM learning.

When I used to start a conversation about neural networks over a bottle of beer, people were casting glances at me of what seemed to be fear; they grew sad, sometimes with their eyelid twitching. In rare cases, they were even eager to take refuge under the table. Why? These networks are simple and instinctive, actually. Yes, believe me, they are! Just let me prove this is true!

Suppose there are two things I’m aware of about the girl: she looks pretty to my taste or not, and I have lots to talk about with her or I haven’t. True and false will be one and zero respectively. We’ll take similar principle for appearance. The question is: “What girl I’ll fall in love with, and why?”

We also can think it straight and uncompromisingly: “If she looks pretty and there’s plenty to talk about, then I will fall in love. If neither is true, then I quit”.

But what if I like the lady but there’s nothing to talk about with her? Or vice versa?

What is my advice for people who want to become game developers? After 25 years in the industry, I do have some advice to offer.

The Worlds Leading Real-time Messaging, Audio & Video Chat Solutions That Made Biggest Impact In 2019


With the growing trend of digitalization, most enterprises have transformed their communication methodology from mainstream to digital. In order to keep up with competitors, companies regularly upgrade their services, specially the way they relay information to their customers as well as their employees. Today, seamless real-time networking plays a critical role in engaging with individuals and enterprises, and the best way to implement such a feat is onboarding a Real-Time Chat, Voice & Video Calling SDK/API providers.

Hi guys,

Before you is an article guide to open data sets for machine learning. In it, I, for a start, will collect a selection of interesting and fresh (relatively) datasets. And as a bonus, at the end of the article, I will attach useful links on independent search of datasets.

Less words, more data.

A selection of datasets for machine learning:

• Data deaths and battles from the game of thrones — This data set combines three data sources, each based on information from a series of books.
• Global Terrorism Database — Over 180,000 terrorist attacks worldwide, 1970-2017.
• Bitcoin, historical data — Bitcoin data with an interval of 1 minute from selected exchanges, January 2012 — March 2019

This week I spent coding my very first public pet-app based on Telegram chat bot which acts as a Bitcoin wallet and allows to send and receive tips between Telegram users and other so-called “Lightning Apps”. I assume that you are familiar with Bitcoin & Telegram in general, i’ll try to post short and without deep jump into details. More resources about Bitcoin can be found here and Telegram is simply an instant messenger that allows you to create your custom apps (chat-bots) using their platform.

What are the key points of such app?

• Allows to rate other users ideas and answers with real value instead of
  ‘virtual likes’. This brings online conversation to completely new level
• Real example of working micro-payment app which can act with other entities
  over internet using open protocol
• All the modules are open-source projects and can be easy re-used and adjusted
  for your own project. App does not relay on third-party commercial services.
  Even it falls under e-commerce field, which is currently almost closed, the app
  is based on open solutions.

What are the use-cases?

something like this…

Introduction

In early March 2019, Intersoft Eurasia team completed work on a test batch of DO-RA gadgets — personal, cross-platform dosimeters-radiometers to monitor the radiation situation at the measurement site, compatible with iOS and Android smartphones and tablets.

By buying such a device, the user receives the following: reliable electronics which have undergone radiation testing in the factory laboratory, stylish colored case in the spirit of Malevich ;) for every taste, gift packaging, color insert instructions in Russian and English, special USB charging cable, a free updateable DO-RA.Pro application from the App Store and Google Play.

The next step in our project implementation is to find the best sales channels for Made in Russia products in the challenging environment of stagnant purchasing power.

(This is the translation of the original article performed by baragol)

We had a bunch of photographs of the main PCB, a YouTube video with drain-voltage waveforms of MOSFETs, a forum post with a breakdown of the capacitance values of LC circuit capacitors and also a number of unboxing videos showing the heating-up of the soldering tip. The only thing that really worried me was the video with the measurement of the peak power consumption during the heating-up. There is nothing in the world more helpless and irresponsible and depraved than burned cartridge newly bought for 60 bucks from Amazon. But let me start from the beginning.