• How to milk cows with robots and make an industrial startup of it. The history of the R-SEPT development

    • Translation

    In 2017, the media heard a very interesting story about a startup that robotizes milking cows on industrial dairy farms. The company is called R-SEPT, and back then it received 10 million rubles of investment. But a year has passed, and there's still no news on what happened further. We contacted Aleksey Khakhunov (AlexeiHahunov), the founder of the startup, and discussed the development. It turns out that the whole year his team was getting the prototype of the robot into shape, and just a week ago they conducted their first field test on the farm.

    Under the cut there's a story about a robotics student who grew up on his parents' farm, turned the University diploma into an industrial startup, as he collected the first manipulators with his friends, and then scaled up to the level of state programs for the robotization of agriculture. And the most important is how the iron hand of the robot and the machine vision are better than a living milkmaid.
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  • I am a useless idiot, so I want to quit my job: 10 questions to a software developer, a pilot episode

    • Translation

    Hi there, Habr!

    Remember the story of Steve Jobs and Dennis Ritchie? Without any intention to rekindle the debates or moralize on the subject, let’s face the truth: thousands of stellar techies live in the shadow, while their own stories are hidden in a dusty cupboard.

    We, the Habr editorial team, are keen to tackle this injustice. From now on, we will regularly interview people who keep a low profile in media and social networks. So if you have anything to tell about yourself, get ready.

    To give you an idea of what this will look like, we will lead the way. Click below to see 10 general questions we will ask every guest. For our pilot episode, the first guest to answer the questions was fillpackart. (This month I’ve had several quite good interview sessions with him, see articles one, two, three). Please read them, and if you make up your mind on telling your own story in a similar way, just send me or baragol a message.
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  • How does a barcode work?

      Hi all!

      Every person is using barcodes nowadays, mostly without noticing this. When we are buying the groceries in the store, their identifiers are getting from barcodes. Its also the same with goods in the warehouses, postal parcels and so on. But not so many people actually know, how it works.

      What is 'inside' the barcode, and what is encoded on this image?

      Lets figure it out, and also lets write our own bar decoder.
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    • (in)Finite War

        infitite war

        We have a problem. The problem with testing. The problem with testing React components, and it is quite fundamental. It’s about the difference between unit testing and integration testing. It’s about the difference between what we call unit testing and what we call integration testing, the size and the scope.

        It's not about testing itself, but about Component Architecture. About the difference between testing components, standalone libraries, and final applications.

        Everyone knows how to test simple components(they are simple), probably know how to test Applications(E2E). How to test Finite and Infinite things…

        But... no, nobody knows actually.
      • Naming things

          There are only two hard things in Computer Science: cache invalidation
          and naming things.

          — Phil Karlton

          We, developers, spend more time reading code than writing it. It is important for the code to be readable and clear about its intent.

          Below are some advice based on my experience naming things.

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        • Chemistry lesson: how to expose a microchip's crystal for photography


          If you have dabbled into microchip photographing before, then this article will probably not offer much to you. But if you want to get into it, but don’t know where to start, then it’s exactly for you.

          Before we start, a fair warning: while the procedure is quite entertaining, at first it’ll probably be physically painful. The chemicals used during the process are toxic, so please handle them carefully – that way it’ll still hurt, but less so. Also, if you have even a slight amount of common sense, conduct the procedure in a fully-equipped chemical laboratory under supervision of trained professionals: we’ve had to deal with people who tried to do it at home immediately after reading the guide. And finally: if you don’t know whether you need to pour acid into water or water into acid without a Google search and don’t realize what this lack of knowledge will entail – stop reading this immediately and go to a chemistry 101 course in a local college or something.

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        • Running image viewer from Windows XP on modern Windows

            I have a directory with old images which I collected in the noughties. I move it with all my other files from one computer to another on every upgrade. Every now and then, when I feel a bit nostalgic, I open it and look through the pictures. There are a few GIF files with animation, and every time I notice that the default image viewer from Windows 7 does not support it. I remembered, that the image viewer from Windows XP was able to play GIF animation properly. So, I spent a bit of time to overcome a few obstacles and to run the old image viewer on modern Windows, a small launcher was created for this purpose. Now I can watch these old images in authentic interface of the old image viewer from Windows XP.

            Download: shimgvw_xp32.7z (includes a binary and source code of the launcher, and the shimgvw.dll from English Windows XP SP3).

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          • Internet Issues & Availability Report 2018–2019


              While working on the annual report this year we have decided to avoid retelling the news headlines of the previous year and, though it is almost impossible to ignore memories absolutely, we want to share with you the result of a clear thought and a strategic view to the point where we all are going to arrive in the nearest time — the present.

              Leaving introduction words behind, here are our key findings:

              • Average DDoS attack duration dropped to 2.5 hours;
              • During 2018, the capability appeared for attacks at hundreds of gigabits-per-second within a country or region, bringing us to the verge of “quantum theory of bandwidth relativity”;
              • The frequency of DDoS attacks continues to grow;
              • The continuing growth of HTTPS-enabled (SSL) attacks;
              • PC is dead: most of the legitimate traffic today comes from smartphones, which is a challenge for DDoS actors today and would be the next challenge for DDoS mitigation companies;
              • BGP finally became an attack vector, 2 years later than we expected;
              • DNS manipulation has become the most damaging attack vector;
              • Other new amplification vectors are possible, like memcached & CoAP;
              • There are no more “safe industries” that are invulnerable to cyberattacks of any kind.

              In this article we have tried to cherry-pick all the most interesting parts of our report, though if you would like read the full version in English, the PDF is available.
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            • Top 10 bugs of C++ projects found in 2018

                It has been three months since 2018 had ended. For many, it has just flew by, but for us, PVS-Studio developers, it was quite an eventful year. We were working up a sweat, fearlessly competing for spreading the word about static analysis and were searching for errors in open source projects, written in C, C++, C#, and Java languages. In this article, we gathered the top 10 most interesting of them right for you!

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              • Exploiting signed bootloaders to circumvent UEFI Secure Boot

                  Русская версия этой статьи.
                  Modern PC motherboards' firmware follow UEFI specification since 2010. In 2013, a new technology called Secure Boot appeared, intended to prevent bootkits from being installed and run. Secure Boot prevents the execution of unsigned or untrusted program code (.efi programs and operating system boot loaders, additional hardware firmware like video card and network adapter OPROMs).
                  Secure Boot can be disabled on any retail motherboard, but a mandatory requirement for changing its state is physical presence of the user at the computer. It is necessary to enter UEFI settings when the computer boots, and only then it's possible to change Secure Boot settings.

                  Most motherboards include only Microsoft keys as trusted, which forces bootable software vendors to ask Microsoft to sign their bootloaders. This process include code audit procedure and justification for the need to sign their file with globally trusted key if they want the disk or USB flash to work in Secure Boot mode without adding their key on each computer manually.
                  Linux distributions, hypervisors, antivirus boot disks, computer recovery software authors all have to sign their bootloaders in Microsoft.

                  I wanted to make a bootable USB flash drive with various computer recovery software that would boot without disabling Secure Boot. Let's see how this can be achieved.
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                • Citymobil — a manual for improving availability amid business growth for startups. Part 3

                    This is the next article of the series describing how we’re increasing our service availability in Citymobil (you can read the previous parts here and here). In further parts, I’ll talk about the accidents and outages in detail. But first let me highlight something I should’ve talked about in the first article but didn’t. I found out about it from my readers’ feedback. This article gives me a chance to fix this annoying shortcoming.
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                  • What is going to happen on February 1, 2020?

                      TL;DR: starting February 2020, DNS servers that don’t support DNS both over UDP and TCP may stop working.

                      Bangkok, in general, is a strange place to stay. Of course, it is warm there, rather cheap and some might find the cuisine interesting, along with the fact that about half of the world’s population does not need to apply for a visa in advance to get there. However, you still need to get acquainted with the smells, and the city streets are casting cyberpunk scenes more than anything else.

                      In particular, a photo to the left has been taken not far from the center of Thailand’ capital city, one street away from the Shangri-La hotel, where the 30th DNS-OARC organization meeting took place on May 12 and 13. It is a non-profit organization dedicated to security, stability, and overall development of the DNS — the Domain Name System.

                      Slides from the DNS-OARC 30 meeting are recommended for everyone interested in how the DNS works, though perhaps the most interesting is what is absent in those slides. Namely, a 45-minute round table with a discussion around the results of DNS Flag Day 2019, which occurred on February, 1, 2019.

                      And, the most impressive result of a round table is the decision to repeat DNS Flag Day once again.
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                    • Top 5 Tips Developers Should Know For Python Codes Optimization

                      Optimization of Python codes deals with selecting the best option among a number of possible options that are feasible to use for developers. Python is the most popular, dynamic, versatile, and one of the most sought after languages for mobile application development. Right from the programming projects like machine learning and data mining, Python is still the best and most relevant language for application developers.

                      Code Optimization Tips for Python Developers

                      In this post, I will discuss some of the optimization procedures and patterns in Python coding in an effort to improve the overall coding knowledge.

                      Optimizing Slow Code First

                      When you run your Python program, the source code .py is compiled using CPython into bytecode (.pyc file) saved in a folder (_pycache_) and at the end interpreted by Python virtual M2M code (machine to machine). Since Python uses an interpreter to execute the bytecode at runtime which makes the process a bit slower.

                      To make your execution faster on CPython, get PyPy v7.1 that include two different interpreters and the feature of its predecessor PyPy3.6-beta and Python 2.7. Compared to CPython it is 7.6X faster which is critical for coding. Programs in CPython takes a lot of space, but PyPy takes up less space in programs.
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                    • How to quickly check out interesting warnings given by the PVS-Studio analyzer for C and C++ code?

                        Once in a while, programmers who start getting acquainted with the PVS-Studio code analyzer ask me: «Is there a list of warnings that accurately indicate errors?» There is no such list because uninteresting (false) warnings in one project are very important and useful in another one. However, one can definitely start digging into the analyzer from the most exciting warnings. Let's take a closer look at this topic.
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                      • Audio over Bluetooth: most detailed information about profiles, codecs, and devices

                          XKCD comic. How standards proliferate. SITUATION: there are 14 competing standards. Geek: 14?! Ridiculous! We need to develop one universal standard that covery everyone's use cases. Geek's girlfriend: yeah! SOON: Situation: there are 15 competing standards.

                          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.


                          • 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.

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                        • Reverse engineering a high-end soldering station

                            (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.
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                          • IntelliJ IDEA, ReSharper, SonarLint and SonarQube find the same errors, as PVS-Studio — so why do we need PVS-Studio?

                              Sometimes people ask the question, which addresses a certain topic but is actually about another thing. As the saying goes, a competently asked question contains half the answer.

                              Recently I've returned from the JPoint conference, where we first presented our new PVS-Studio analyzer for Java. Interest in static analysis is growing strongly in the last few years, so the audience perceived PVS-Studio enthusiastically. In addition to the positive feedback, as it happens, we had to handle objections. The most frequent objection to the suggestion to try PVS-Studio sounds something like this: «C'mon, why do we try PVS-Studio? We use IntelliJ IDEA, ReSharper, SonarLint and SonarQube. We've run PVS-Studio recently and it found errors, already highlighted by IntelliJ IDEA!»

                              I just can't help but write a small reply note to this comment. I even have two responses to this objection. And yes, I intentionally stated ReSharper, as there are some questions to our C# analyzer as well. Well, here comes the answer.
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