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    <title>lewinb.net - Lewin Bormann on Lewin Bormann</title>
    <link>https://lewinb.net/</link>
    <description>Recent content in lewinb.net - Lewin Bormann on Lewin Bormann</description>
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    <item>
      <title>See more on SkySee</title>
      <link>https://lewinb.net/posts/29_skysee_developed/</link>
      <pubDate>Tue, 17 Mar 2026 18:59:26 +0100</pubDate>
      <guid>https://lewinb.net/posts/29_skysee_developed/</guid>
      <description>&lt;p&gt;After I released &lt;a href=&#34;../28_skysee&#34;&gt;the first version of SkySee&lt;/a&gt; - see &lt;a href=&#34;https://skysee.ch&#34;&gt;skysee.ch&lt;/a&gt; - I quickly received&#xA;feedback, and also felt myself, the limits of a pure SHV number based tagging. To recap, Swiss glider pilots are&#xA;obligated to put their Swiss paragliding/delta association (SHV) membership number on the down-facing side of their&#xA;glider, for accountability purposes. The original SkySee idea was to repurpose this number for sharing flight photos&#xA;among pilots.&lt;/p&gt;&#xA;&lt;p&gt;However, depending on the perspective, in dynamic situations, or from far away, the letters can not always be read&#xA;easily; especially on snapshots or videos with limited resolution. In addition, there are plans to replace the physical&#xA;SHV number with an electronic identification system in the next few years: so the days of SHV number tagging would be&#xA;limited anyway.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Building SkySee</title>
      <link>https://lewinb.net/posts/28_skysee/</link>
      <pubDate>Fri, 06 Feb 2026 17:18:38 +0100</pubDate>
      <guid>https://lewinb.net/posts/28_skysee/</guid>
      <description>&lt;h2 id=&#34;context&#34;&gt;Context&lt;/h2&gt;&#xA;&lt;p&gt;In the past weeks, I&amp;rsquo;ve built a web application from the ground up, scratching an itch I&amp;rsquo;ve had for&#xA;a long time. Since fall 2024, I&amp;rsquo;ve been the proud owner of a Swiss paragliding license, and I&amp;rsquo;ve&#xA;been making use of this privilege quite a bit (but not as much as I would have liked).&lt;/p&gt;&#xA;&lt;p&gt;My second-favorite part of a day going flying is the time spent in between flights. Whether that&amp;rsquo;s&#xA;talking to other pilots, hiking, eating lunch, or taking photos. This means I&amp;rsquo;ve ended up with a&#xA;whole lot of photos of other pilots: sometimes during the final leg before landing, or during their&#xA;take-off, and often enough even while in the air.&lt;/p&gt;</description>
    </item>
    <item>
      <title>News in uvco</title>
      <link>https://lewinb.net/posts/27_uvco_news/</link>
      <pubDate>Sun, 07 Dec 2025 12:52:35 +0100</pubDate>
      <guid>https://lewinb.net/posts/27_uvco_news/</guid>
      <description>&lt;p&gt;How time passes! This is already the third article discussing my &lt;a href=&#34;https://github.com/dermesser/uvco&#34;&gt;uvco&lt;/a&gt; library for&#xA;asynchronous programming in C++ - the &lt;a href=&#34;https://lewinb.net/tags/uvco&#34;&gt;uvco tag&lt;/a&gt; shows all past and future articles.&lt;/p&gt;&#xA;&lt;p&gt;The reason for this installment are several fundamental improvements I&amp;rsquo;ve implemented in recent weeks, turning the&#xA;fledgling, sometimes unstable and hard to use uvco library discussed in those previous articles, into a more robust and&#xA;scalable framework for almost-serious asynchronous programming in C++. In addition, several benchmarks have been&#xA;implemented to better quantify the throughput and latency numbers currently achievable with uvco.&lt;/p&gt;</description>
    </item>
    <item>
      <title>But what is a Quantum Control System?</title>
      <link>https://lewinb.net/posts/26_qcs/</link>
      <pubDate>Tue, 21 Oct 2025 09:32:14 +0200</pubDate>
      <guid>https://lewinb.net/posts/26_qcs/</guid>
      <description>&lt;p&gt;In my job at Zurich Instruments, I&amp;rsquo;m busy most days building software for a &lt;em&gt;quantum control system&lt;/em&gt; (QCS). And even&#xA;though that&amp;rsquo;s something very tangible for me, it&amp;rsquo;s often difficult to explain to folks outside of the field, and&#xA;sometimes I struggle to describe precisely to other physicists what a QCS is or does.&lt;/p&gt;&#xA;&lt;p&gt;So first, for a working definition we use internally: A QCS is a system used in building quantum computers, specifically&#xA;concerned with controlling the individual qubits. Each qubit is a discrete physical system typically exhibiting two&#xA;energy states, and by coupling them to each other, quantum computations can be executed on the quantum computer. How&#xA;specifically that works is beyond this discussion (and also beyond me, if I&amp;rsquo;m honest). Oftentimes, the chip (if it is a&#xA;chip) containing qubits is called the &lt;em&gt;QPU&lt;/em&gt;, or Quantum Processing Unit, in analogy to the CPU or GPU. But as I will&#xA;describe further down, this term is not quite clear and can be used in a different way. Also note that despite having an&#xA;education in physics, I&amp;rsquo;m working on the QCS &lt;em&gt;software&lt;/em&gt; &amp;ndash; I have many extremely competent colleagues with PhDs in&#xA;quantum computing who are much better able to explain the finer aspects of quantum computing.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Design of the uvco async library</title>
      <link>https://lewinb.net/posts/25_uvco_design/</link>
      <pubDate>Tue, 30 Jul 2024 22:06:26 +0200</pubDate>
      <guid>https://lewinb.net/posts/25_uvco_design/</guid>
      <description>&lt;p&gt;&lt;strong&gt;&lt;center&gt;New article, discussing recent developments and improvements: &lt;a href=&#34;https://lewinb.net/posts/27_uvco_news&#34;&gt;News in uvco&lt;/a&gt;&lt;/center&gt;&lt;/strong&gt;&lt;/p&gt;&#xA;&lt;p&gt;I&amp;rsquo;ve already presented my &amp;ldquo;uvco&amp;rdquo; library in a &lt;a href=&#34;https://lewinb.net/posts/21_uvco_asynchronous_library/&#34;&gt;previous post&lt;/a&gt;. Here I want to go&#xA;deeper on the underlying design ideas and mechanics of using C++ coroutines to make using libuv a lot more ergonomic&#xA;than otherwise.&lt;/p&gt;&#xA;&lt;p&gt;The outcome is similar to e.g. Node.js concurrency - not surprising, because that&amp;rsquo;s still libuv&amp;rsquo;s main use case - or Python&amp;rsquo;s&#xA;&lt;code&gt;asyncio&lt;/code&gt; library.&lt;/p&gt;&#xA;&lt;h2 id=&#34;getting-started-with-c-coroutines&#34;&gt;Getting Started with C++ coroutines&lt;/h2&gt;&#xA;&lt;p&gt;When coroutines were first standardized, I was looking forward to using them. Having used Go before, I hoped that&#xA;writing concurrent and parallel code would finally become more accessible in C++. However, if you read references for&#xA;C++ coroutines, you&amp;rsquo;ll notice that they never talk about concurrency at all. That was initially a bit difficult to&#xA;understand, and I wasn&amp;rsquo;t quite sure what coroutines would be good for then.&lt;/p&gt;</description>
    </item>
    <item>
      <title>ELF Linking and Loading in Practice</title>
      <link>https://lewinb.net/posts/24_elf_linking_and_loading/</link>
      <pubDate>Mon, 22 Apr 2024 19:28:54 +0200</pubDate>
      <guid>https://lewinb.net/posts/24_elf_linking_and_loading/</guid>
      <description>&lt;p&gt;I&amp;rsquo;ve programmed in C and C++, later in Rust and OCaml, for more than 12 years now. One of the most interesting aspects&#xA;to me were the operating system, how code interacts with it, and how code is run. Like most people, I followed the&#xA;typical journey: compile your first code using &lt;code&gt;gcc -c hello.c&lt;/code&gt;, then link it using &lt;code&gt;gcc -o hello hello.o&lt;/code&gt;, and finally&#xA;run it using &lt;code&gt;./hello&lt;/code&gt;. With &lt;a href=&#34;https://github.com/dermesser/libsocket&#34;&gt;libsocket&lt;/a&gt; I published a library for both C and&#xA;C++, facilitating using the sockets API on Unix systems - and as a library, I had to learn how to build a dynamic&#xA;library (shared object, SO), and how to link against it. I&amp;rsquo;ve had my fair share of linker errors, too, but one thing&#xA;stood out to me: linking and loading are complex processes, but generally so reliable that they almost always work. And&#xA;if they don&amp;rsquo;t it&amp;rsquo;s usually my own fault - a missing translation unit, or something similar.&lt;/p&gt;</description>
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    <item>
      <title>A simple Priority Queue in OCaml</title>
      <link>https://lewinb.net/posts/22_priorityqueue_ocaml/</link>
      <pubDate>Sat, 30 Dec 2023 18:26:38 +0100</pubDate>
      <guid>https://lewinb.net/posts/22_priorityqueue_ocaml/</guid>
      <description>&lt;p&gt;While working on some programming quiz in &lt;a href=&#34;https://lewinb.net/tags/ocaml&#34;&gt;OCaml&lt;/a&gt;, I needed to use a priority queue (or&#xA;heap) in order to solve some graph traversal problem. However, unfortunately, OCaml doesn&amp;rsquo;t provide&#xA;any sort of priority queue or heap in its standard library. And after a brief search I haven&amp;rsquo;t found&#xA;any that satisfied me in terms of their interface.&lt;/p&gt;&#xA;&lt;p&gt;However, in I came across the idea to simply use a &lt;code&gt;Set&lt;/code&gt; keyed by &lt;code&gt;(int * &#39;a)&lt;/code&gt; where &lt;code&gt;int&lt;/code&gt; is the&#xA;priority and &lt;code&gt;&#39;a&lt;/code&gt; the payload. That&amp;rsquo;s clever! The access complexity for the min (or max) element is&#xA;now &lt;code&gt;log N&lt;/code&gt; but that is still better than not having a proper heap. I also didn&amp;rsquo;t feel like writing&#xA;my own heap based on an array or a simple tree structure; making use of the well-known &lt;code&gt;Base.Set&lt;/code&gt;&#xA;module seemed more attractive. I generally use Jane Street&amp;rsquo;s &lt;code&gt;Base&lt;/code&gt; and &lt;code&gt;Core&lt;/code&gt; all the time, as they&#xA;are a bit more pleasant to use and more complete than the standard library.&lt;/p&gt;</description>
    </item>
    <item>
      <title>The uvco C&#43;&#43; async library</title>
      <link>https://lewinb.net/posts/21_uvco_asynchronous_library/</link>
      <pubDate>Sun, 26 Nov 2023 23:37:20 +0100</pubDate>
      <guid>https://lewinb.net/posts/21_uvco_asynchronous_library/</guid>
      <description>&lt;p&gt;&lt;em&gt;Updated: May 7, 2024&lt;/em&gt;&lt;/p&gt;&#xA;&lt;p&gt;&lt;strong&gt;&lt;center&gt;New article, going in depth on uvco: &lt;a href=&#34;https://lewinb.net/posts/25_uvco_design&#34;&gt;Design of the uvco async library&lt;/a&gt;&lt;/center&gt;&lt;/strong&gt;&lt;/p&gt;&#xA;&lt;p&gt;Since starting my new position at &lt;a href=&#34;http://zhinst.com&#34;&gt;Zurich&#xA;Instruments&lt;/a&gt; I&amp;rsquo;ve worked a lot with the lovely  &lt;code&gt;kj&lt;/code&gt;&#xA;framework, in conjunction with &lt;a href=&#34;http://capnproto.org/&#34;&gt;capnproto RPC&lt;/a&gt;. &lt;code&gt;kj&lt;/code&gt; is&#xA;an asynchronous network programming library, and gained support for C++&#xA;coroutines in &lt;a href=&#34;https://capnproto.org/news/2023-07-28-capnproto-1.0.html&#34;&gt;version&#xA;1.0&lt;/a&gt;. For this use&#xA;case, coroutines are great, simplify usage, and may even yield performance&#xA;improvements.&lt;/p&gt;&#xA;&lt;p&gt;To get a better understanding, I attempted my hand at writing a small coroutine&#xA;framework driven by the &lt;a href=&#34;http://libuv.org&#34;&gt;libuv&lt;/a&gt; event loop. While there were&#xA;some snags to be navigated, this turned out to be a great fit, and I quickly&#xA;managed to map a good part of its functionality to a coroutine-based&#xA;implementation.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Functional JSON Access</title>
      <link>https://lewinb.net/posts/20_functional_json_access/</link>
      <pubDate>Sat, 26 Aug 2023 13:49:15 +0200</pubDate>
      <guid>https://lewinb.net/posts/20_functional_json_access/</guid>
      <description>&lt;p&gt;While working on &lt;a href=&#34;https://lewinb.net/posts/19_typst_of_jupyter/&#34;&gt;typst_of_jupyter&lt;/a&gt;, I came across a very common problem: efficiently and&#xA;reliably accessing nested JSON structures. This is an age-old problem that every programmer will have come across, and&#xA;it&amp;rsquo;s easier in some languages &amp;ndash; dynamically typed ones like Python or JavaScript &amp;ndash; and more annoying in others.&lt;/p&gt;&#xA;&lt;p&gt;typst_of_jupyter is written in &lt;a href=&#34;https://ocaml.org/&#34;&gt;OCaml&lt;/a&gt;, which &amp;ndash; being statically typed &amp;ndash; rather falls into the&#xA;second category. In order to generate typst code for a Jupyter notebook, the JSON structure representing the notebook&#xA;must be processed. It is not a very complicated structure, but enough to be annoying to deal with in a plain way.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Typst_of_jupyter: Better notebook PDFs</title>
      <link>https://lewinb.net/posts/19_typst_of_jupyter/</link>
      <pubDate>Thu, 27 Jul 2023 00:30:02 +0200</pubDate>
      <guid>https://lewinb.net/posts/19_typst_of_jupyter/</guid>
      <description>&lt;p&gt;If you have followed my posts (unlikely, given the visitor counts of my website), you have seen&#xA;&lt;a href=&#34;https://lewinb.net/posts/14_typst_and_a_cv_template/&#34;&gt;one&lt;/a&gt; or &lt;a href=&#34;https://lewinb.net/posts/15_typst_for_technical_documentation/&#34;&gt;two&lt;/a&gt; posts about&#xA;&lt;a href=&#34;https://typst.app&#34;&gt;Typst&lt;/a&gt;, the new text-based typesetting system. I&amp;rsquo;ve already shown in &lt;a href=&#34;https://lewinb.net/posts/15_typst_for_technical_documentation/&#34;&gt;a previous&#xA;post&lt;/a&gt; that Typst can be very useful as an intermediate language for&#xA;generating PDFs.&lt;/p&gt;&#xA;&lt;p&gt;Disappointed by the various ways of exporting &lt;a href=&#34;https://jupyter.org&#34;&gt;Jupyter notebooks&lt;/a&gt; &amp;ndash; printing from the browser, converting to LaTeX,&#xA;pandoc, etc. &amp;ndash; I was looking for an approach that allows for archiving and sharing high-quality versions of Jupyter&#xA;notebooks preferably as PDF files. The idea to use Typst for generating such PDFs was obvious!&lt;/p&gt;</description>
    </item>
    <item>
      <title>Playing with OCaml Effects</title>
      <link>https://lewinb.net/posts/17_playing_with_ocaml_effects/</link>
      <pubDate>Sun, 23 Jul 2023 15:40:04 +0200</pubDate>
      <guid>https://lewinb.net/posts/17_playing_with_ocaml_effects/</guid>
      <description>&lt;p&gt;A few weeks ago I finally started seriously working with &lt;a href=&#34;https://ocaml.org/&#34;&gt;OCaml&lt;/a&gt;, after having ignored it for a long&#xA;time. The main reason was the lack for multithreading, which I felt is essential these days (even though most code, of&#xA;course, doesn&amp;rsquo;t make use of it.) But OCaml 5 was released a few months ago, and has removed this barrier &amp;ndash; along with&#xA;introducing &lt;a href=&#34;https://dl.acm.org/doi/pdf/10.1145/3453483.3454039&#34;&gt;&lt;em&gt;Effect handlers&lt;/em&gt;&lt;/a&gt;, a smooth way for handling all kinds&#xA;of ways to hack a program&amp;rsquo;s control flow.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Foothills of Zug</title>
      <link>https://lewinb.net/photos/11_foothills/</link>
      <pubDate>Fri, 21 Jul 2023 23:31:49 +0200</pubDate>
      <guid>https://lewinb.net/photos/11_foothills/</guid>
      <description>&lt;p&gt;The &amp;ldquo;secret&amp;rdquo; to the most cliché idyllic landscapes is to not look in the alpine regions, but in the foothills preceding&#xA;them. In this case, in the canton of Zug between Aegerisee and Raten pass (1080 m above sea level). With the farmers&#xA;rushing to take in hay before the arriving rainstorm, the perfect scene was set.&lt;/p&gt;&#xA;&lt;p&gt;No more talk &amp;ndash; the photos speak for themselves:&lt;/p&gt;&#xA;&lt;p&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6507942.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6507942_hu_753a26e1a1d3cb46.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6507949.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6507949_hu_1a9fcd90db78558f.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6507954.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6507954_hu_282ed8a690505bf7.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6507971.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6507971_hu_48199c9c4c7dce8e.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=47.14444722222222,8.658848333333333&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6507979.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6507979_hu_aec7c7b033b9a44.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=47.14659944444444,8.65796388888889&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6507983.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6507983_hu_ac365c247f00d9d8.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=47.147615277777774,8.657154444444444&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6508005.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6508005_hu_88ba8e9ccbe80e26.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=47.14789583333333,8.655621944444444&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6508023.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6508023_hu_ca9658a2eaa71a.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=47.14953583333333,8.652457222222223&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6508030.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6508030_hu_9b88dd4f851c43b6.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Mount Rigi and Pilatus, near Lucerne.&lt;/b&gt; &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=47.141504166666664,8.663085555555556&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6508032.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6508032_hu_38e718d57af9f35f.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=47.14151361111111,8.663044166666667&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/11_foothills/D6508043.JPG&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/11_foothills/D6508043_hu_a1015c124f53718e.JPG&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Mount Rigi (on the right)&lt;/b&gt; &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=47.141551388888885,8.662883333333333&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&lt;/p&gt;</description>
    </item>
    <item>
      <title>The Law of Lawyers</title>
      <link>https://lewinb.net/posts/16_law_of_lawyers/</link>
      <pubDate>Sun, 18 Jun 2023 13:47:26 +0200</pubDate>
      <guid>https://lewinb.net/posts/16_law_of_lawyers/</guid>
      <description>&lt;h2 id=&#34;background&#34;&gt;Background&lt;/h2&gt;&#xA;&lt;p&gt;Over the past years, I&amp;rsquo;ve repeatedly seen articles claiming a looming shortage of lawyers:&lt;/p&gt;&#xA;&lt;ul&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://www.thomsonreuters.com/en-us/posts/legal/long-term-legal-labor-shortage/&#34;&gt;Reuters: &amp;ldquo;Could the legal industry be entering a long-term lawyer labor shortage?&amp;rdquo;&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://www.deutschlandfunk.de/juristen-mangel-in-deutschland-zu-wenige-richter-und-lange-100.html&#34;&gt;Deutschlandfunk: &amp;ldquo;Zu wenige Richter und lange Justiz-Verfahren&amp;rdquo;&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://apnews.com/article/georgia-justice-judiciary-courts-lawyer-shortage-fa4c1c5fceeaaca635cfad8dbbb27d2f&#34;&gt;AP: &amp;ldquo;Georgia chief justice says lawyer shortage slows down courts&amp;rdquo;&lt;/a&gt;&lt;/li&gt;&#xA;&lt;/ul&gt;&#xA;&lt;p&gt;But I&amp;rsquo;ve wondered: is such a shortage serious, and more importantly, would having more lawyers (which in the following&#xA;also includes judges and so on, essentially jurists) help ameliorating the situation?&lt;/p&gt;</description>
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    <item>
      <title>Typst for Technical Documentation</title>
      <link>https://lewinb.net/posts/15_typst_for_technical_documentation/</link>
      <pubDate>Fri, 16 Jun 2023 17:49:37 +0200</pubDate>
      <guid>https://lewinb.net/posts/15_typst_for_technical_documentation/</guid>
      <description>&lt;p&gt;In my second post on Typst &amp;ndash; after the &lt;a href=&#34;https://lewinb.net/posts/14_typst_and_a_cv_template/&#34;&gt;CV template&lt;/a&gt; which already ranks me fairly&#xA;high in the search results for those terms :-) &amp;ndash; I want to present a use case of Typst I found while working on my&#xA;master&amp;rsquo;s thesis on integrated photonics devices for multiplexing at low temperatures.&lt;/p&gt;&#xA;&lt;p&gt;That use case is short techical reports respectively &amp;ldquo;data sheets&amp;rdquo;, and I&amp;rsquo;m proud that this one too doesn&amp;rsquo;t fall under&#xA;the apparently intended main application of Typst, which would be writing (academic) publications. In addition, I&amp;rsquo;ve&#xA;also written various pieces of technical documentation with it, but those are rather conventional (and could have easily&#xA;been written in LaTex or Word).&lt;/p&gt;</description>
    </item>
    <item>
      <title>Typst and a CV template</title>
      <link>https://lewinb.net/posts/14_typst_and_a_cv_template/</link>
      <pubDate>Sun, 23 Apr 2023 10:41:18 +0200</pubDate>
      <guid>https://lewinb.net/posts/14_typst_and_a_cv_template/</guid>
      <description>&lt;p&gt;&lt;em&gt;Updated 2023-08-30&lt;/em&gt;&lt;/p&gt;&#xA;&lt;p&gt;If you are interested in typesetting outside the normal options (Word, LibreOffice), and have had a gnawing feeling that&#xA;LaTeX is, after all, a bit annoying to use (and I say that as a maybe not power user, but having used it for the past&#xA;ten years, including all important documents), &lt;a href=&#34;https://typst.app&#34;&gt;Typst&lt;/a&gt; may be for you.&lt;/p&gt;&#xA;&lt;p&gt;It&amp;rsquo;s a new document language, conceptually somewhere between LaTeX and Markdown, has been hyped a bit recently &amp;ndash; and&#xA;that hype is fully deserved. Having had no experience in it, I rewrote my CV on a Sunday morning&#xA;within less than two hours, and it looks better than the prior LaTeX version. Written in Rust, it is easily installable&#xA;through &lt;code&gt;cargo&lt;/code&gt;, as a standalone binary, or usable on the web. I went the first route (as a matter of pride).&lt;/p&gt;</description>
    </item>
    <item>
      <title>Just some cat photos</title>
      <link>https://lewinb.net/photos/10_just_some_cat_photos/</link>
      <pubDate>Wed, 19 Apr 2023 20:58:32 +0200</pubDate>
      <guid>https://lewinb.net/photos/10_just_some_cat_photos/</guid>
      <description>&lt;p&gt;I&amp;rsquo;ve recently had the privilege of meeting several lovely cats who agreed to have their photos taken (at least that&amp;rsquo;s&#xA;how I interpreted their behavior).&lt;/p&gt;&#xA;&lt;p&gt;All photos except for the last one were taken with my &lt;a href=&#34;https://lewinb.net/photos/04_auto_revuenon/&#34;&gt;&lt;em&gt;Auto Revuenon f/1.4 55mm&lt;/em&gt;&lt;/a&gt; lens.&lt;/p&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/10_just_some_cat_photos/uediker_buesi.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/10_just_some_cat_photos/uediker_buesi_hu_b971483b006487df.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Uediker Büsi&lt;/b&gt; &#xA;        &#xA;        &#xA;        &#xA;         ---- &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&lt;p&gt;This Dorito-colored cat visited my garden a few days ago. We&amp;rsquo;d been acquainted already when it came out of its house (in&#xA;my neighborhood) to get a pat on the head one night.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Thermal Limits of Quantum Compting</title>
      <link>https://lewinb.net/posts/13_thermal_limits_of_quantum_computing/</link>
      <pubDate>Sun, 25 Dec 2022 14:30:17 +0100</pubDate>
      <guid>https://lewinb.net/posts/13_thermal_limits_of_quantum_computing/</guid>
      <description>&lt;p&gt;&lt;em&gt;Disclaimer: I have little knowledge about the details of quantum computing!&#xA;Neither do you need any to understand this short article.&lt;/em&gt;&lt;/p&gt;&#xA;&lt;p&gt;I am working on my master&amp;rsquo;s thesis these days, or more specifically the&#xA;research that will hopefully lead to having something to write about. While I&#xA;cannot go into details due to my host institutes customs on intellectual&#xA;property etc. &amp;ndash; the world will have to wait for my thesis to be published &amp;ndash; I&#xA;am fortunately allowed to talk about the context and the problem. Later on, I&#xA;hope to write a few more articles on the specific technologies I am using, while&#xA;remaining at a high enough abstraction level to not violate any rules. I also&#xA;won&amp;rsquo;t go into extreme details: for that you will have to wait for my master&amp;rsquo;s&#xA;thesis.&lt;/p&gt;</description>
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    <item>
      <title>What Every Programmer Should Know About Optical Fiber</title>
      <link>https://lewinb.net/posts/12_what_every_programmer_should_know_about_optical_fiber/</link>
      <pubDate>Mon, 15 Aug 2022 22:53:25 -0700</pubDate>
      <guid>https://lewinb.net/posts/12_what_every_programmer_should_know_about_optical_fiber/</guid>
      <description>&lt;p&gt;Could you imagine an internet with just text? No photos, no audio, and certainly no video? Forget&#xA;about memes, Youtube, and Netflix! All these very essential services could simply not exist&#xA;without&amp;hellip; &lt;strong&gt;Optical Fiber&lt;/strong&gt;!&lt;/p&gt;&#xA;&lt;p&gt;So when compiling a list of technologies with the highest impact on our daily lives, optical fiber&#xA;would certainly take up one of the top spots. As long as the internet is mentioned, fiber needs to&#xA;be credited. The main question that I had for years, as programmer, software engineer, and generally&#xA;computer person &amp;ndash; and that probably you might have too, if you have read anything about&#xA;fiber-related technologies &amp;ndash; is: &lt;em&gt;how is fiber so damn fast?&lt;/em&gt;&lt;/p&gt;</description>
    </item>
    <item>
      <title>The Sony Zeiss 16-70mm f/4 Lens</title>
      <link>https://lewinb.net/photos/09_sony_ze_1670/</link>
      <pubDate>Sat, 30 Jul 2022 22:08:20 -0700</pubDate>
      <guid>https://lewinb.net/photos/09_sony_ze_1670/</guid>
      <description>&lt;p&gt;After noticing that by far most visitors to my website don&amp;rsquo;t come for my technical/scientific&#xA;content (sad!) but for my &lt;a href=&#34;https://lewinb.net/photos/04_auto_revuenon/&#34;&gt;Auto Revuenon review&lt;/a&gt;, I figured I may expand&#xA;my portfolio of &lt;a href=&#34;https://lewinb.net/tags/lensreview&#34;&gt;lens reviews&lt;/a&gt;, and present more of my not-so-rare knowledge and&#xA;probably-wrong opinions publicly.&lt;/p&gt;&#xA;&lt;p&gt;Thus: This review of &lt;strong&gt;Sony&amp;rsquo;s Z 16-70 mm f/4 E&lt;/strong&gt; lens, or fully &lt;strong&gt;Vario-Tessar T* E 16-70 mm F4 ZA&#xA;OSS&lt;/strong&gt;, or technically just &lt;strong&gt;SEL1670Z&lt;/strong&gt;.&lt;/p&gt;&#xA;&lt;h2 id=&#34;overview&#34;&gt;Overview&lt;/h2&gt;&#xA;&lt;p&gt;The technical aspects you can find on &lt;a href=&#34;https://www.sony.com/electronics/support/lenses-e-mount-lenses/sel1670z/specifications&#34;&gt;Sony&amp;rsquo;s&#xA;site&lt;/a&gt;, and I&#xA;won&amp;rsquo;t repeat them here. Instead I&amp;rsquo;ll provide my subjective impression so far (no shots of diagrams&#xA;or walls either). You can click the images to obtain a full-size (camera-resolution) JPEG.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Hollywood Hills</title>
      <link>https://lewinb.net/photos/08_hollywoodhills/</link>
      <pubDate>Fri, 24 Jun 2022 21:54:00 -0700</pubDate>
      <guid>https://lewinb.net/photos/08_hollywoodhills/</guid>
      <description>&lt;p&gt;I walked off the busy Hollywood streets &amp;ndash; with the LA pride in full swing &amp;ndash; into the Hollywood&#xA;hills. Looking at all these rich people&amp;rsquo;s houses didn&amp;rsquo;t do much to help my confidence. At least it&#xA;was a colorful and impressive walk. 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/&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.111972216666665,-118.33094388333333&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/241.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/241_hu_37399af8d6be04a0.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11452083333333,-118.33036638333333&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/248.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/248_hu_a8ba868b35a08667.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11513721666667,-118.32896638333334&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/249.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/249_hu_da22f7152acb597e.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11514833333333,-118.32893638333333&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/252.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/252_hu_3f8762531961e234.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11530388333333,-118.32701305&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/253.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/253_hu_2a9f73441a4c8c23.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11524915,-118.32711083333334&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/256.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/256_hu_69195b06caac304d.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.115220816666664,-118.32683943333333&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/263.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/263_hu_e6875a31b9a76599.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11533055,-118.32813748333334&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/269.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/269_hu_53cb6b2beb100a3b.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.115649166666664,-118.32853&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/270.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/270_hu_1a31ffdc1273deb1.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11567,-118.32850666666667&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/274.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/274_hu_a5e1b7391e64340c.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11607805,-118.32971026666667&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/283.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/283_hu_917ff9c3f3423fe0.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11767416666667,-118.33040555&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/285.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/285_hu_7f03f3cc0b7df76f.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11770526666667,-118.33037888333334&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/286.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/286_hu_1ed7cb1c2e8ed487.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.1176675,-118.33034555&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/302.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/302_hu_b5db54fbfa352647.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.11796416666667,-118.33223581666667&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/308.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/308_hu_7e4d62522e3000f3.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.10188,-118.31662331666666&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/08_hollywoodhills/312.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/08_hollywoodhills/312_hu_47c457b765ee47c3.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;        &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=34.101885833333334,-118.31630248333333&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         E 16-70mm F4 ZA OSS &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&lt;/p&gt;</description>
    </item>
    <item>
      <title>Weighted Means - a Bayesian View</title>
      <link>https://lewinb.net/posts/11_weighted_mean_bayesian_view/</link>
      <pubDate>Wed, 25 May 2022 20:37:01 -0700</pubDate>
      <guid>https://lewinb.net/posts/11_weighted_mean_bayesian_view/</guid>
      <description>&lt;p&gt;Every student in quantitative sciences &amp;ndash; I will argue &amp;ndash; sooner or later comes across the weighted&#xA;mean, a tool to incorporate measurements with different uncertainties into a overall measurement of&#xA;better uncertainty than any single measurement. This is commonly defined for measurements $x_i$ with&#xA;uncertainties $\sigma_i$ as the following:&lt;/p&gt;&#xA;&lt;p&gt;$$\overline x = \frac{\sum_i x_i/\sigma_i^2}{\sum_i 1/\sigma_i^2}$$&#xA;$$\overline\sigma^2 = \sum_i \frac{1}{\sigma_i^2}$$&lt;/p&gt;&#xA;&lt;p&gt;It is straight-forward to interpret this as a weighted sum of measurements, with &amp;ldquo;better&amp;rdquo;&#xA;(low-uncertainty/high-precision) measurements receiving a higher weight than less precise ones.&lt;/p&gt;</description>
    </item>
    <item>
      <title>California</title>
      <link>https://lewinb.net/photos/07_california/</link>
      <pubDate>Tue, 03 May 2022 22:03:42 -0700</pubDate>
      <guid>https://lewinb.net/photos/07_california/</guid>
      <description>&lt;p&gt;Staying in California obviously gives some great opportunities to take amazing photos. The ones you&#xA;can see are just a small taste; you can see a much greater selection on&#xA;&lt;a href=&#34;https://flic.kr/s/aHBqjzGG6B&#34;&gt;Flickr&lt;/a&gt;. Click images to magnify.&lt;/p&gt;&#xA;&lt;ul&gt;&#xA;&lt;li&gt;&lt;a href=&#34;#kingscanyon&#34;&gt;Kings Canyon&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;#davis&#34;&gt;Davis&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;#campus&#34;&gt;UC Davis Campus&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;#reyes&#34;&gt;Point Reyes&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;#yosemite&#34;&gt;Yosemite National Park&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;#berryessa&#34;&gt;Lake Berryessa&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;#coaststarlight&#34;&gt;Amtrak Coast Starlight (Davis - Los Angeles)&lt;/a&gt;&lt;/li&gt;&#xA;&lt;/ul&gt;&#xA;&lt;h2 id=&#34;kingscanyon&#34;&gt;Kings Canyon/Sequoia National Park&lt;/h2&gt;&#xA;&lt;p&gt;&lt;a href=&#34;https://flic.kr/s/aHBqjzQg7r&#34;&gt;(Flickr)&lt;/a&gt;&lt;/p&gt;&#xA;&lt;p&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/07_california/kc0.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/07_california/kc0_hu_1ed19fde30549a19.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Driving to Kings Canyon&lt;/b&gt; &#xA;        &#xA;        &#xA;        &#xA;         FE 50mm F1.8 &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/07_california/kc2.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/07_california/kc2_hu_43e8e34e57ce9d49.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Road into Kings Canyon/Roads End&lt;/b&gt; &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=36.82257555,-118.83532638333334&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         30mm F1.4 DC DN | Contemporary 016 &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/07_california/kc3.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/07_california/kc3_hu_31115ffea0ad8b3f.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;View of Palmer Mountain&lt;/b&gt; &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=36.805878316666664,-118.54671083333334&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         30mm F1.4 DC DN | Contemporary 016 &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/07_california/kc4.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/07_california/kc4_hu_9caae87647b096b5.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Secret submarine base?&lt;/b&gt; &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=36.830436666666664,-118.54293443333333&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         30mm F1.4 DC DN | Contemporary 016 &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/07_california/kc5.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/07_california/kc5_hu_497eb46911016c89.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Driving in the Canyon&lt;/b&gt; &#xA;        &#xA;        &#xA;        &#xA;         30mm F1.4 DC DN | Contemporary 016 &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/07_california/kc1.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/07_california/kc1_hu_3022b5004cab1141.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Sunset over Kings Canyon NP&lt;/b&gt; &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=36.83367388333333,-118.90087416666667&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         30mm F1.4 DC DN | Contemporary 016 &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&#xA;&lt;a href=&#34;https://lewinb.net/photos/07_california/kc6.jpg&#34; target=&#34;_blank&#34; &gt;&#xA;    &lt;img src=&#34;https://lewinb.net/photos/07_california/kc6_hu_7f695c0d0e89d720.jpg&#34; /&gt;&#xA;&lt;/a&gt;&#xA;&lt;center&gt;&lt;i&gt;&#xA;         &lt;b&gt;Old redwood stumps (Big Stump Grove)&lt;/b&gt; &#xA;        &#xA;        &#xA;        (&lt;a href=&#34;https://maps.google.com/?q=36.71828055,-118.96747331666667&#34; target=&#34;_blank&#34;&gt;Location&lt;/a&gt;) &#xA;         30mm F1.4 DC DN | Contemporary 016 &#xA;    &#xA;&lt;/i&gt;&lt;/center&gt;&#xA;&lt;/p&gt;</description>
    </item>
    <item>
      <title>Miscellaneous</title>
      <link>https://lewinb.net/miscellaneous/</link>
      <pubDate>Thu, 14 Apr 2022 20:53:20 -0700</pubDate>
      <guid>https://lewinb.net/miscellaneous/</guid>
      <description>&lt;p&gt;&lt;em&gt;Minor works or interesting tidbits go here. Don&amp;rsquo;t expect great insights!&lt;/em&gt;&lt;/p&gt;&#xA;&lt;ul&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://lewinb.net/doc/vorticity.pdf&#34;&gt;Derivation of the (full and quasigeostrophic) Vorticity and Divergence equations (ATM 111 class, UC Davis)&lt;/a&gt;&#xA;&lt;ul&gt;&#xA;&lt;li&gt;This is of interest to those excited about atmospheric dynamics. Otherwise, it probably isn&amp;rsquo;t.&lt;/li&gt;&#xA;&lt;/ul&gt;&#xA;&lt;/li&gt;&#xA;&lt;/ul&gt;</description>
    </item>
    <item>
      <title>Some data algorithms</title>
      <link>https://lewinb.net/posts/10_some_data_algorithms/</link>
      <pubDate>Thu, 17 Mar 2022 17:22:16 +0100</pubDate>
      <guid>https://lewinb.net/posts/10_some_data_algorithms/</guid>
      <description>&lt;p&gt;In the past half year, I&amp;rsquo;ve implemented various data analytics algorithms for my own understanding.&#xA;Mostly on a toy level, they are all implemented in Julia as Pluto notebooks and I hope they are&#xA;helpful as reference (if only for me). Here&amp;rsquo;s the line-up:&lt;/p&gt;&#xA;&lt;ul&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://lewinb.net/doc/data/adaboost.jl.html&#34;&gt;&lt;em&gt;AdaBoost&lt;/em&gt;&lt;/a&gt; &amp;ndash; how to use enough shitty classifiers to make up a&#xA;not-so-shitty classifier. &lt;em&gt;(Note: the last plot is supposed to contain a heatmap, which sometimes&#xA;only shows up after refreshing the page)&lt;/em&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://lewinb.net/doc/data/EM.jl.html&#34;&gt;&lt;em&gt;Expectation Maximization&lt;/em&gt;&lt;/a&gt; &amp;ndash; k-means clustering, but better&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://lewinb.net/doc/data/GLM.jl.html&#34;&gt;&lt;em&gt;GLM&lt;/em&gt;&lt;/a&gt; &amp;ndash; generalized linear models for multi-class classification&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://lewinb.net/doc/data/logistic.jl.html&#34;&gt;&lt;em&gt;logistic&lt;/em&gt;&lt;/a&gt; &amp;ndash; logistic regression; similar to GLM (but less general)&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://lewinb.net/doc/data/SVM.jl.html&#34;&gt;&lt;em&gt;SVM&lt;/em&gt;&lt;/a&gt; &amp;ndash; the old-but-gold classic, here implemented in four flavors.&lt;/li&gt;&#xA;&lt;/ul&gt;&#xA;&lt;p&gt;I hope they are useful to you (although probably not). Either way, note how easy Julia makes it to&#xA;implement these (admittedly simple) algorithms, compared to e.g. Python with numpy. For example,&#xA;being able to take the gradient of a function without further troubles (like frameworks&#xA;etc.) is often very useful for quickly optimizing some function; and matrix arithmetics are easier&#xA;to use anyway.&lt;/p&gt;</description>
    </item>
    <item>
      <title>More Coupled Oscillators</title>
      <link>https://lewinb.net/posts/09_more_coupled_oscillators/</link>
      <pubDate>Wed, 19 Jan 2022 21:35:54 +0100</pubDate>
      <guid>https://lewinb.net/posts/09_more_coupled_oscillators/</guid>
      <description>&lt;p&gt;A very important concept in condensed matter physics (or solid-state physics, specifically) are&#xA;lattice vibrations and their quantized form, phonons. I&amp;rsquo;ve mentioned before that I like using a&#xA;computational approach to better understand concepts, and it&amp;rsquo;s not different here.&lt;/p&gt;&#xA;&lt;p&gt;I will assume no prior knowledge on your part, and additionally, I want to state that I don&amp;rsquo;t claim&#xA;to be anything but a humble student of this matter. If you find errors, please let me know&#xA;discretely to save me the embarrassment :)&lt;/p&gt;</description>
    </item>
    <item>
      <title>Integer Programming (and Operations Research)</title>
      <link>https://lewinb.net/posts/08_integer-programming/</link>
      <pubDate>Wed, 01 Dec 2021 21:59:40 +0100</pubDate>
      <guid>https://lewinb.net/posts/08_integer-programming/</guid>
      <description>&lt;p&gt;&lt;em&gt;updated: 2021-12-27&lt;/em&gt;&lt;/p&gt;&#xA;&lt;p&gt;Towards the end of my Bachelor&amp;rsquo;s program, I decided to broaden my horizon and expand my options &amp;ndash;&#xA;and subsequently enrolled not only for Master&amp;rsquo;s studies in Physics, but also in Economics. This is&#xA;a special curriculum offered by my university for students of science and engineering.&lt;/p&gt;&#xA;&lt;p&gt;Long story short, whereas some courses are quite, hm, boring &amp;ndash; I&amp;rsquo;ve been amazed by the &lt;em&gt;Operations&#xA;Research I&lt;/em&gt; lecture (given by Prof. Lübbecke). In fact, I even chose Operations Research as the&#xA;focus of studies for the economics degree. But what is Operations Research (OR) in the first place?&#xA;Being very much a beginner in this field, I don&amp;rsquo;t dare give a good definition or even overview of&#xA;it. Generally, this field is concerned with optimization problems, often discrete ones, with&#xA;applications in business, logistics, government, military, and so on. Typical problems in OR are route&#xA;planning (including travelling sales person/TSP), packing, scheduling, allocation of resources, and&#xA;so on.&lt;/p&gt;</description>
    </item>
    <item>
      <title>RWTH in Fall</title>
      <link>https://lewinb.net/photos/06_rwth_fall/</link>
      <pubDate>Thu, 11 Nov 2021 22:17:48 +0100</pubDate>
      <guid>https://lewinb.net/photos/06_rwth_fall/</guid>
      <description>&lt;p&gt;I like taking photos of my university campus; so much, in fact, that I&amp;rsquo;ve created a &lt;a href=&#34;https://www.flickr.com/groups/rwthaachen/&#34;&gt;Flickr group&#xA;dedicated to it&lt;/a&gt;. These days, the late fall light gives&#xA;some special feeling to the Melaten campus especially (that&amp;rsquo;s the part built as a greenfield project&#xA;some time in the 1970s, I believe).&lt;/p&gt;&#xA;&lt;p&gt;My endearingly snarky treatment of my &lt;em&gt;alma mater&lt;/em&gt; is well-deserved, and I hope some things will&#xA;change in the upcoming years. Except for the bunnies, of course.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Bachelor thesis</title>
      <link>https://lewinb.net/posts/07_bachelor/</link>
      <pubDate>Thu, 14 Oct 2021 14:06:37 +0200</pubDate>
      <guid>https://lewinb.net/posts/07_bachelor/</guid>
      <description>&lt;p&gt;I spent this past summer writing my Bachelor of Science thesis at RWTH Aachen&amp;rsquo;s &lt;em&gt;Nuclear&#xA;Verification and Disarmament&lt;/em&gt; chair (Prof. Malte Goettsche) about &lt;em&gt;Reconstructing Nuclear Fuel&#xA;Cycles using Bayesian Inference: A First Implementation&lt;/em&gt;.&lt;/p&gt;&#xA;&lt;p&gt;Recently, I received the feedback, which will hopefully soon result in me getting my &amp;ldquo;BSc RWTH&amp;rdquo;&#xA;degree. For my work, I received a 1.0 grade (which is the best grade on the German scale of 1.0 -&#xA;4.0); for this, I&amp;rsquo;m obviously happy. I am grateful for the support I received by Prof. Goettsche as&#xA;well as my supervisor, Max Schalz. Computing resources were provided by RWTH Aachen&amp;rsquo;s data center.&lt;/p&gt;</description>
    </item>
    <item>
      <title>(DE) Wieso eigentlich keine Kernenergie?</title>
      <link>https://lewinb.net/posts/06_wieso-keine-kernenergie/</link>
      <pubDate>Mon, 30 Aug 2021 11:24:58 +0200</pubDate>
      <guid>https://lewinb.net/posts/06_wieso-keine-kernenergie/</guid>
      <description>&lt;p&gt;&lt;em&gt;This article about why nuclear energy is questionable in this day and age is written in German, as&#xA;the topic of leaving nuclear energy is actively discussed in these days in Germany.&lt;/em&gt;&lt;/p&gt;&#xA;&lt;p&gt;In diesen Tagen der Klimakrise &amp;ndash; Wälder im Mittelmeer verbrennen, deutsche Städte werden&#xA;hinweggeschwemmt, der neue IPCC-Report warnt vor Erreichen des 1.5-Grad-Ziels bis 2030 &amp;ndash; hört man&#xA;immer wieder von Kernenergie. Glücklicherweise nicht an prominentester Stelle, doch hin und wieder von&#xA;Kolumnisten und Kommentatoren in der einen oder anderen Publikation.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Ordinary</title>
      <link>https://lewinb.net/photos/05_ordinary/</link>
      <pubDate>Wed, 14 Jul 2021 21:58:40 +0200</pubDate>
      <guid>https://lewinb.net/photos/05_ordinary/</guid>
      <description>&lt;p&gt;Unfortunately not always, but sometimes, I have a mind free enough to just go out and take photos.&#xA;Aachen definitely has some nice corners, but isn&amp;rsquo;t known for its breathtaking&#xA;all-encompassing beauty (as opposed to, say, Monschau &amp;ndash; a nearby, very picturesque village). All&#xA;the more interesting is the consequence of this lack of specialty: even &lt;strong&gt;ordinary&lt;/strong&gt; things can look&#xA;interesting when they are inside a photo, maybe with a bit of color corrections and definitely a&#xA;&lt;em&gt;tastefully&lt;/em&gt; blurred background.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Bayesian Inference</title>
      <link>https://lewinb.net/posts/05_bayesian-inference/</link>
      <pubDate>Wed, 23 Jun 2021 22:39:44 +0200</pubDate>
      <guid>https://lewinb.net/posts/05_bayesian-inference/</guid>
      <description>&lt;p&gt;&lt;em&gt;updated 2021-07-14&lt;/em&gt;&lt;/p&gt;&#xA;&lt;p&gt;&amp;ldquo;Bayesian Inference&amp;rdquo; &amp;ndash; sounds fancy, eh? So non-frequentist, machine-learny,&#xA;does it not? Anyway, I hadn&amp;rsquo;t really heard too much about it before, but had to&#xA;invest some time understanding it in order to work on my BSc thesis (proposed&#xA;title: &lt;em&gt;Reconstructing Nuclear Fuel Cycles Using Bayesian Inference: a first&#xA;implementation&lt;/em&gt;), and now I seem to see it everywhere.&lt;/p&gt;&#xA;&lt;p&gt;But let&amp;rsquo;s start with the &lt;em&gt;Bayes&lt;/em&gt; in &lt;em&gt;Bayesian inference&lt;/em&gt;.&#xA;If you are like me, then you&amp;rsquo;ve probably heard about Bayes&amp;rsquo; theorem, which is&#xA;usually presented in the form&lt;/p&gt;</description>
    </item>
    <item>
      <title>The Auto Revuenon 55/1.4 Lens</title>
      <link>https://lewinb.net/photos/04_auto_revuenon/</link>
      <pubDate>Mon, 14 Jun 2021 11:07:03 +0200</pubDate>
      <guid>https://lewinb.net/photos/04_auto_revuenon/</guid>
      <description>&lt;p&gt;Just recently I bought an Auto Revuenon 55mm (f/1.4) lens off of ebay. It came&#xA;with an M42 screw mount, fitting an adapter that I&amp;rsquo;d already had. For less than&#xA;€40, it didn&amp;rsquo;t take a lot of time to decide; and the fact that I confused it&#xA;with the multi-coated &lt;strong&gt;50mm&lt;/strong&gt; f/1.4 lens, which actually appears to be quite a&#xA;bit better, probably also helped. I had hoped that in comparison to my Zenit&#xA;Helios 44-2, the larger aperture (1.4 vs 2.0, implying twice as much light!)&#xA;would allow for photos taken in even darker conditions. And, of course, more&#xA;bokeh. Because that&amp;rsquo;s what we all want, after all.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Linear &#34;Machine Learning&#34;</title>
      <link>https://lewinb.net/posts/04_linear-meachine-learning/</link>
      <pubDate>Sat, 12 Jun 2021 07:39:44 +0200</pubDate>
      <guid>https://lewinb.net/posts/04_linear-meachine-learning/</guid>
      <description>&lt;p&gt;There is this meme floating around (you can google for it, and find many&#xA;instances), that machine learning is just statistics (and sometimes even just a&#xA;linear regression). While this is obviously simplifying how it is, the&#xA;techniques to do either are similar: you can &amp;ldquo;learn&amp;rdquo; a linear regression, and a&#xA;linear regression can look from the outside like a machine learning algorithm.&#xA;(Provided a simple enough problem)&lt;/p&gt;&#xA;&lt;p&gt;Personally, I&amp;rsquo;m more fascinated by fundamental techniques in machine learning.&#xA;While deep learning is all fun and so on, going back to the roots is what really&#xA;interests me. So I wanted to see how to easily implement a linear model using&#xA;what can be described as &amp;ldquo;machine learning&amp;rdquo;.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Geohub</title>
      <link>https://lewinb.net/posts/03_geohub/</link>
      <pubDate>Sat, 22 May 2021 21:11:10 +0200</pubDate>
      <guid>https://lewinb.net/posts/03_geohub/</guid>
      <description>&lt;p&gt;&lt;strong&gt;&lt;a href=&#34;https://github.com/dermesser/geohub&#34;&gt;Geohub on Github&lt;/a&gt;&lt;/strong&gt;&lt;/p&gt;&#xA;&lt;p&gt;A couple months ago I finally realized an idea that I&amp;rsquo;d had for several years.&#xA;Not a breakthrough idea, mind you, but something I thought would be nice to&#xA;have, and that to me didn&amp;rsquo;t exist yet.&lt;/p&gt;&#xA;&lt;p&gt;Specifically, I&amp;rsquo;d wanted a system for e.g. my phone to send location data to,&#xA;which could then both be stored in a structured form and be available for later&#xA;analysis, and also be available live for tracking applications. Thus, &lt;strong&gt;Geohub&lt;/strong&gt;&#xA;was born, which I (somewhat sarcastically) call a &lt;em&gt;real-time geo data&#xA;framework&lt;/em&gt;.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Light at Night</title>
      <link>https://lewinb.net/photos/03_nightlights/</link>
      <pubDate>Sun, 16 May 2021 21:19:08 +0200</pubDate>
      <guid>https://lewinb.net/photos/03_nightlights/</guid>
      <description>&lt;p&gt;One of my favorite kind of scenes is nightly cities. Recently this has become a&#xA;bit more difficult due to the nightly curfews &amp;ndash; but as more people are becoming&#xA;vaccinated, I hope to soon be able to take photos at night again.&lt;/p&gt;&#xA;&lt;p&gt;The two most important elements in my mind are a stabilizer in your camera or&#xA;lens, and a bright lens: f/1.8 is ok, f/1.4 is good. Then you don&amp;rsquo;t even need a&#xA;tripod.&lt;/p&gt;</description>
    </item>
    <item>
      <title>RWTH Wallpapers</title>
      <link>https://lewinb.net/photos/02_rwth_wallpaper/</link>
      <pubDate>Sat, 15 May 2021 23:48:25 +0200</pubDate>
      <guid>https://lewinb.net/photos/02_rwth_wallpaper/</guid>
      <description>&lt;p&gt;The RWTH&amp;rsquo;s general student&amp;rsquo;s committee (AStA) put out a call for Zoom (video&#xA;conference) background images, in order to &amp;ldquo;spice up&amp;rdquo; the online studies. I&#xA;already had quite some images in the bank, so it was an easy decision to submit&#xA;some of my favorite motives of Aachen. These are some of my submissions:&lt;/p&gt;&#xA;&lt;p&gt;&lt;img src=&#34;https://lewinb.net/img/photo/wallpaper/01.jpg&#34; alt=&#34;The new administrative building, Super C&#34;&gt;&#xA;The flagship administrative building, called Super C.&lt;/p&gt;&#xA;&lt;p&gt;&lt;img src=&#34;https://lewinb.net/img/photo/wallpaper/02.jpg&#34; alt=&#34;Pariser Ring, in the morning&#34;&gt;&#xA;Pariser Ring, near the modern Campus Melaten in the west of Aachen.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Diffraction</title>
      <link>https://lewinb.net/posts/02_diffraction/</link>
      <pubDate>Sat, 15 May 2021 20:58:52 +0200</pubDate>
      <guid>https://lewinb.net/posts/02_diffraction/</guid>
      <description>&lt;p&gt;Inspired by drudging through optics material for a recent exam, I wanted to get&#xA;a more intuitive feeling for diffraction phenomena, specifically diffraction of&#xA;spherical waves through a plane aperture.&lt;/p&gt;&#xA;&lt;h2 id=&#34;setup&#34;&gt;Setup&lt;/h2&gt;&#xA;&lt;p&gt;The most general still-understandable way of calculating diffraction of such a&#xA;configuration is the Kirchhoff diffraction formula. We assume at least one point&#xA;source in a distance $z_s$ from the screen at $z = 0$, which emits a wave&lt;/p&gt;</description>
    </item>
    <item>
      <title>Technical Aspects of Nuclear Verification</title>
      <link>https://lewinb.net/posts/01_technical_aspects/</link>
      <pubDate>Fri, 14 May 2021 19:45:07 +0200</pubDate>
      <guid>https://lewinb.net/posts/01_technical_aspects/</guid>
      <description>&lt;p&gt;As part of a seminar I recently took with Prof. Göttsche from the &lt;em&gt;Nuclear&#xA;Verification and Disarmament&lt;/em&gt; group at RWTH, I wrote a handout about the&#xA;technical aspects of verifying nuclear arms treaties. It touches on satellite&#xA;and aerial surveillance, radar, infrared, seismic, and acoustic methods, and how&#xA;these different methods fit into the international arms control regime.&lt;/p&gt;&#xA;&lt;p&gt;You can read the &lt;a href=&#34;https://lewinb.net/doc/TechnicalAspectsOfVerification.pdf&#34;&gt;result here&lt;/a&gt;.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Majestic Sunrays</title>
      <link>https://lewinb.net/photos/01_clouds/</link>
      <pubDate>Fri, 14 May 2021 12:46:06 +0200</pubDate>
      <guid>https://lewinb.net/photos/01_clouds/</guid>
      <description>&lt;p&gt;Aachen is &amp;ndash; at least among locals &amp;ndash; known for its brilliant sunsets and&#xA;dramatic weather. Here, we see a dark cloud mixture pierced by bright rays of&#xA;sunlight. No wonder people used to believe in angels!&lt;/p&gt;&#xA;&lt;p&gt;&lt;img src=&#34;https://lewinb.net/img/photo/20210514_clouds.jpg&#34; alt=&#34;Clouds&#34;&gt;&lt;/p&gt;&#xA;&lt;p&gt;&lt;img src=&#34;https://lewinb.net/img/photo/20210514_glitter.jpg&#34; alt=&#34;Glittery Sunset&#34;&gt;&lt;/p&gt;&#xA;&lt;p&gt;Taken with Helios 44-2 through my slightly rained-on kitchen window.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Resume</title>
      <link>https://lewinb.net/resume/</link>
      <pubDate>Fri, 14 May 2021 12:22:17 +0200</pubDate>
      <guid>https://lewinb.net/resume/</guid>
      <description>&lt;p&gt;Please &lt;a href=&#34;https://lewinb.net/contact&#34;&gt;contact&lt;/a&gt; me and I will gladly send you my CV in either English or German language!&lt;/p&gt;</description>
    </item>
    <item>
      <title>About</title>
      <link>https://lewinb.net/about/</link>
      <pubDate>Fri, 14 May 2021 08:15:25 +0200</pubDate>
      <guid>https://lewinb.net/about/</guid>
      <description>&lt;p&gt;Hi there! &amp;ndash; I&amp;rsquo;m Lewin, owner of this little website. I&amp;rsquo;m living in Switzerland, working for Zurich Instruments on the&#xA;software stack for quantum computing control systems. Fortunately, that is the best thing I can currently imagine&#xA;working on, and I&amp;rsquo;m having great fun!&lt;/p&gt;&#xA;&lt;h3 id=&#34;what-came-before&#34;&gt;What came before&lt;/h3&gt;&#xA;&lt;p&gt;My career started right after high school, when I joined Google in Zürich (Switzerland) back in 2014, and worked for&#xA;four years as Systems Engineer in Site Reliability Engineering (&lt;a href=&#34;https://sre.google&#34;&gt;sre.google&lt;/a&gt;). There, I took care of&#xA;Google Docs, Google Drive, and later, Borg &amp;ndash; the global computing grid that all of Google runs on. Although it was my&#xA;dream job, I left it in 2018  &amp;ndash; to fulfill my long-held dream of studying physics.&lt;/p&gt;</description>
    </item>
    <item>
      <title>Contact</title>
      <link>https://lewinb.net/contact/</link>
      <pubDate>Fri, 14 May 2021 08:15:25 +0200</pubDate>
      <guid>https://lewinb.net/contact/</guid>
      <description>&lt;h1 id=&#34;lewin-bormann&#34;&gt;Lewin Bormann&lt;/h1&gt;&#xA;&lt;p&gt;You can reach me by email at &lt;em&gt;info - at - lewinb.net&lt;/em&gt;, or on&#xA;Telegram at @lewinb. I have accounts on different platforms as well:&lt;/p&gt;&#xA;&lt;ul&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://www.linkedin.com/in/lewin-bormann&#34;&gt;LinkedIn&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://github.com/dermesser&#34;&gt;GitHub&lt;/a&gt;&lt;/li&gt;&#xA;&lt;li&gt;&lt;a href=&#34;https://flickr.com/lewinb&#34;&gt;Flickr&lt;/a&gt;&lt;/li&gt;&#xA;&lt;/ul&gt;</description>
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