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	<title>Konstantin Shemyak - blog</title>
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	<link>http://www.konstantin.shemyak.com/blog</link>
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		<title>Web surfing privacy and being multilingual</title>
		<link>http://www.konstantin.shemyak.com/blog/2010/02/15/web-surfing-privacy-and-being-multilingual/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2010/02/15/web-surfing-privacy-and-being-multilingual/#comments</comments>
		<pubDate>Mon, 15 Feb 2010 14:37:19 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[IT]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=353</guid>
		<description><![CDATA[In many cases, it&#8217;s easy to track your browsing &#8211; thanks to JavaScript which is by default executed in most browsers. For example, any site can figure out did you visit a particular another site or not. Like, find out which social networks you hang in. So far, it was mostly about showing more targeted [...]]]></description>
			<content:encoded><![CDATA[<p>In many cases, it&#8217;s easy to track your browsing &#8211; thanks to JavaScript which is by default executed in most browsers. For example, any site can figure out did you visit a particular another site or not. Like, <a href="http://whattheinternetknowsaboutyou.com/docs/details.html">find out which social networks you hang in</a>. So far, it was mostly about showing more targeted advertisements.</p>
<p>Nothing bad has happened to me because of this, and one may argue that targeted ads are better than non-targeted. But I do not like the idea of being tracked &#8211; and I shut off all web ads anyway with <a href="http://adblockplus.org/">AdBlock</a>. Additionally, I have <a href="http://noscript.net/">NoScript</a> always on (and allow sites selectively each time when &#8220;some site does not work&#8221;).</p>
<p>Today I have been told that there is a way to track me even without JavaScript and tracking images from spyhouse sites. It is demonstrated here:</p>
<p><a href="https://panopticlick.eff.org/">https://panopticlick.eff.org/</a></p>
<p>I have quite long &#8220;<em>accept-language</em>&#8221; header set in my browsers, as I can read web pages in several languages. panopticlick shows that I&#8217;m one such user out of about half million (it might be that I&#8217;m just the only one with this value of <em>accept-language</em>, who made a check there).</p>
<p>I&#8217;m not feeling paranoid because of this. But I&#8217;ll be happy to know, is there a way to pass my (complicated <img src='http://www.konstantin.shemyak.com/blog/wp-includes/images/smilies/icon_smile.gif' alt=':)' class='wp-smiley' />  ) language preferences without allowing for easy fingerprinting.</p>
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		<title>Winter fun plus a survival training</title>
		<link>http://www.konstantin.shemyak.com/blog/2010/01/28/winter-fun-plus-a-survival-training/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2010/01/28/winter-fun-plus-a-survival-training/#comments</comments>
		<pubDate>Thu, 28 Jan 2010 08:24:10 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[Outdoors]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=335</guid>
		<description><![CDATA[ We have a beautiful, real winter here in Finland. The weather I just desire: stable negative temperature never creeping to zero, enough snow for any winter fun &#8211; about which I may blog more some time later. One of the cool things to do this time of the year is to ski, skate, walk [...]]]></description>
			<content:encoded><![CDATA[<p><a href="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2010/01/27012010305.jpg"><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2010/01/27012010305-300x219.jpg" alt="27012010305" title="27012010305" width="300" height="219" class="alignleft size-medium wp-image-336" /></a> We have a beautiful, real winter here in Finland. The weather I just desire: stable negative temperature never creeping to zero, enough snow for any winter fun &#8211; about which I may blog more some time later. One of the cool things to do this time of the year is to ski, skate, walk or cycle over the frozen water. For example, last cold (or, better say, just normal) winter of year 2003 we <a href="http://konstantin.shemyak.com/cycling/Alands/">cycled from the Åland archipelago to the continental Finland</a>. When not going this far, I regularly ski around the Suvisaaristo islands next to which I live (<a href="http://maps.google.com/maps/ms?ie=UTF8&#038;hl=en&#038;msa=0&#038;msid=118397091897014227191.00047c9509a45819e6ab0&#038;ll=60.12165,24.701684&#038;spn=0.078332,0.2108&#038;z=12">recorded route here</a>). Moving over ice is great!</p>
<p>But what if the ice breaks and you fall in the zero degrees cold water? </p>
<p>There is a simple answer: try this before it hits. Your chances to get out alive become higher. Read on for the boring theory and a short report of how I did this recently in a mild -17&deg;C afterwork evening.<span id="more-335"></span></p>
<p>The first thing to really understand is that <strong>this can happen</strong>. If you ever move on the ice, this can happen <strong>to you</strong>. I learned it from my own experience.</p>
<p>So, the second thing is <strong>to be prepared</strong>. In this case, being prepared is relatively easy. </p>
<p>There is a general &#8220;smart&#8221; advice: <em>do not panic, know the theory, act calm and fast</em>. Anyone who had ever been in a stress situation knows that the latter can&#8217;t be just easily followed. When the life is at stake, all your skills can degrade in one moment down to what is learned in practice. So &#8211; just do it. </p>
<ul>
<li>Find an ice opening, where you can safely get out. In Finland, we have maintained winter swimming spots which are perfect for this task</li>
<li>Call a friend or two who will pull out your body on a rope in case something gets really wrong.</li>
<li>Make sure they actually can do it &#8211; test this on the ground first; one should be reasonably fit in order to be able to lift a person of similar weight. </li>
<li>Prepare full change of the clothes, including shoes. (Never attempt such fun disrobed. You can cut yourself with ice edges.)</li>
<li>Read more theory below.</li>
</ul>
<p><a href="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2010/01/Jaanaskalit.jpg"><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2010/01/Jaanaskalit-300x218.jpg" alt="Jaanaskalit" title="Jaanaskalit" width="300" height="218" class="alignleft size-medium wp-image-343" /></a></p>
<p>It&#8217;s nice to practice next to a warm place &#8211; a house or a car, which you can jump into after the exercise. But in fact I recommend doing it without such possibility. Getting out of the water is just first stage of your game; second, maybe equally dangerous and sometimes underestimated stage is recovering your warmth afterward. Climbed out, one may fall in an euphoric feeling &#8220;I did it&#8221; and end up with <a href="http://en.wikipedia.org/wiki/Frostbite">frostbitten</a> extremities. (For ones looking for real horror pictures of frostbitten hands, see <a href="http://www.e1.ru/talk/forum/read.php?f=106&#038;i=133031&#038;t=133031&#038;page=0">bottom of this page</a>. And the story started innocently: small dipping in water in the cold.) You&#8217;ll know fascinating details: wet shoelaces freeze and you can&#8217;t take the shoes off; zippers freeze and do not open; and so on. Reading about such issues from a computer screen does not always deliver the idea that this is serious.</p>
<p>One more &#8220;do-and-do-not&#8221; list:</p>
<ul>
<li><strong>always</strong> carry awls with which to climb out of the opening back to the ice (pictured above; <em>jäänaskalit</em> in Finnish; I wonder how is it called in English or Russian). In some cases, it may be impossible to climb out, as the ice may be slippery and your hands just slide helplessly. They must be hanging on the neck, not in a backpack or a pocket.</li>
<li><strong>always</strong> carry some spare clothes. Full set is the best; at least something is a must. It must be packed so that it stays dry after your potential bathing</li>
<li>climb out <strong>to the direction you came from</strong></li>
<li>when got out, <strong>immediately</strong> do whatever you can to the wet clothes (in 15 minutes, it may be already too late) &#8211; change it if you have change, wriggle it as good as you can otherwise</li>
<li><strong>never</strong> take alcohol or anything like that.</li>
</ul>
<p><a href="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2010/01/27012010306.jpg"><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2010/01/27012010306-300x203.jpg" alt="27012010306" title="27012010306" width="300" height="203" class="alignleft size-medium wp-image-338" /></a></p>
<p>So, how was it in practice? Pretty cool. Real winter fun (with necessary precautions). Unfortunately, the water level in our test lake was lower than I expected &#8211; just up to shoulders, so I could actually stay and push myself up. This made climbing out easier than it might have been. I climbed first time without pulling the awls out; but I guess the possibility to jump on the bottom makes a huge difference. After that, I decided to still test the awls and crashed ice edge the second time. Naturally, it was even easier.</p>
<p>Now I would like to repeat the exercise in a place where I do not reach the bottom with feet. And of course getting a bit nicer pictures does not harm. It may be not immediately clear without explanation, that the picture to the left shows a floating object in the ice opening, and that this object is in fact me giving a short lecture on how it feels.</p>
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		<title>HP photosmart c8180: perfect Linux support</title>
		<link>http://www.konstantin.shemyak.com/blog/2009/11/29/hp-photosmart-c8180-perfect-linux-support/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2009/11/29/hp-photosmart-c8180-perfect-linux-support/#comments</comments>
		<pubDate>Sun, 29 Nov 2009 13:26:02 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[IT]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=327</guid>
		<description><![CDATA[Short summary of this post: HP Photosmart C8180 all-in-one printer works perfectly with Linux right out of the box.

After our older printer has died, I had to select a new one. There is too many printers in the market, but the choice decision for me is easier: I just look for Linux support at the [...]]]></description>
			<content:encoded><![CDATA[<p><a href="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/11/hp-photosmart-c8180.jpg"><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/11/hp-photosmart-c81801.jpg" alt="hp-photosmart-c8180" title="hp-photosmart-c8180" width="170" height="112" class="alignleft size-full wp-image-328" /></a>Short summary of this post: HP Photosmart C8180 all-in-one printer works perfectly with Linux right out of the box.<br />
<span id="more-327"></span><br />
After our older printer has died, I had to select a new one. There is too many printers in the market, but the choice decision for me is easier: I just look for Linux support at the vendor site, plus availability in the local store. Note: nowadays, most printers work with Linux thanks to the volunteer effort; but I want to pay my money to the company, which claims the support officially. This pretty much narrows the selection to HP and Epson (and I can&#8217;t think of a situation when the offer from these two vendors is not enough). Quotes from their web sites:</p>
<ul>
<li>&#8220;Epson tests and certifies most common Linux and Unix platforms with our printers&#8221; (quote from <a href="http://www.business-solutions.epson.co.uk/Compatible.htm">here</a>)</li>
<li>&#8220;The HP Linux Imaging and Printing project provides printing support for 1,949 printer models&#8221; (quote from <a href="http://hplipopensource.com/hplip-web/supported_devices/index.html">here</a>)</li>
</ul>
<p>Finally, my choice has fallen on HP c8180. At this moment, <a href="http://openprinting.org">openprinting.org</a>, the source for Linux printer support information, does not list this model (it&#8217;s quite new). But having configured it as &#8220;HP C8100 series&#8221; in Ubuntu 9.10, both printing and scanning work just fine right out of the box without any additional installations or configurations.</p>
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		<title>Self-made ultralight camelbak</title>
		<link>http://www.konstantin.shemyak.com/blog/2009/11/07/self-made-ultralight-camelbak/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2009/11/07/self-made-ultralight-camelbak/#comments</comments>
		<pubDate>Sat, 07 Nov 2009 13:27:12 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[Cycling]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=318</guid>
		<description><![CDATA[ This is my DIY ultralight water bag. The bag itself, without the bladder, weighs 20 grams.

Normally I do not need any &#8220;hydration systems&#8221;. In fact their justifications, like &#8220;hydrate or die&#8221; or &#8220;drink up to 24% more&#8221; sound completely idiotic to me. Exception is the endurance winter bike rides with local Espoo cycling club [...]]]></description>
			<content:encoded><![CDATA[<p><a href="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/11/self-made-camelback.jpg"><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/11/self-made-camelback-150x150.jpg" alt="self-made-ultralight-camelbak" title="self-made-ultralight-camelbak" width="150" height="150" class="alignleft size-thumbnail wp-image-319" /></a> This is my DIY ultralight water bag. The bag itself, without the bladder, weighs 20 grams.<br />
<span id="more-318"></span><br />
Normally I do not need any &#8220;hydration systems&#8221;. In fact their justifications, like <em>&#8220;hydrate or die&#8221;</em> or <em>&#8220;drink up to 24% more&#8221;</em> sound completely idiotic to me. Exception is the <a href="http://www.fillarikalenteri.fi/eventinstance/486/2009-11-1">endurance winter bike rides</a> with local Espoo cycling club <a href="http://www.ik-32.org/">IK-32</a>. Water in the bottles freezes while we ride for 5-6 hours non-stop in sub-zero temperatures &#8211; and it&#8217;s hard to explain to the unexperienced what you think about your water bottles in such case. Most often it means that you quit the ride, founding yourself in sweat-through clothes within some 40 km towards home. Even when it&#8217;s a bit above 0&deg;C, as it is now, drinking water warm is much better than ice-cold.</p>
<p>Other riders carry water bottles in their back pockets, but my jacket has pockets which are not really suitable for it. So I decided to try a camelbak.  But models in the store make my digestive tract to work in the wrong direction. Such simple thing as bag for the plastic water bladder is made of tens of various colorful cloth pieces, contains plastic foam padding everywhere, several strips and bindings all over the body, and <strong>weighs up to <font size="bigger">500g!</font></strong> I&#8217;m not much of a weightweenie, but half-kilo just does not make any sense here. All this plastic foam and nylon base becomes completely wet during the ride, I&#8217;d have to carry half kilogram more of own sweat each time, and wash it away at home. And for these rides, grams actually matter: for me, it easily can mean keeping up with the group until the end or dropping out somewhere in the middle.</p>
<p>I realized that I&#8217;m not taking any of these fancy ready camelbaks even for free. I bought just the plastic water bladder (it was marked &#8220;Platypus&#8221;, weighted 120 g.) and sew quickly an ultra-thin nylon cover for it together with two thin, minimally padded shoulder straps. The latter attach directly to the top closing of the bladder. As I said, all my creature weighs <strong>20 grams</strong> and does not collect more sweat than the inner lining of the jacket. In fact even much less.</p>
<p>Last weekend this masterpiece was successfully tested. I didn&#8217;t drop out of the ride. Well, the pace was a bit more peaceful than it had been some times before. Here is the map.</p>
<p><iframe width="320" height="480" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="http://maps.google.com/maps/ms?ie=UTF8&amp;hl=en&amp;msa=0&amp;msid=118397091897014227191.000477513deb3e7ad5bb9&amp;ll=60.348696,24.602509&amp;spn=0.32611,0.439453&amp;z=10&amp;output=embed"></iframe><br /><small><a href="http://maps.google.com/maps/ms?ie=UTF8&amp;hl=en&amp;msa=0&amp;msid=118397091897014227191.000477513deb3e7ad5bb9&amp;ll=60.348696,24.602509&amp;spn=0.32611,0.439453&amp;z=10&amp;source=embed" style="color:#0000FF;text-align:left">View in a larger map</a></small></p>
<p>It worked! It takes 2l of fluid and weighs less than 2 x 1l. standard water bottles with holders. I&#8217;m taking it next time.</p>
<p>See you on the ride!</p>
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		<title>Nexus-7 exact ratios and tooth counts &#8220;from the source&#8221;</title>
		<link>http://www.konstantin.shemyak.com/blog/2009/10/27/nexus-7-exact-ratios-and-tooth-counts-from-the-source/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2009/10/27/nexus-7-exact-ratios-and-tooth-counts-from-the-source/#comments</comments>
		<pubDate>Tue, 27 Oct 2009 12:48:49 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[Cycling]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=295</guid>
		<description><![CDATA[Previously, I have tried to find &#8220;theoretically&#8221; the tooth counts of the Nexus-7 internal gear hub. Some nice numbers were obtained, but there were some suspects (you may think yourself what can be wrong with the numbers given in the link). Soon after, I disassembled the real hub and counted the teeth of all rings. [...]]]></description>
			<content:encoded><![CDATA[<p>Previously, <a href="http://konstantin.shemyak.com/blog/2009/10/22/nexus-7-gear-tooth-counts-and-exact-transmission-ratios/">I have tried to find &#8220;theoretically&#8221; the tooth counts of the Nexus-7 internal gear hub</a>. Some nice numbers were obtained, but there were some suspects (you may think yourself what <strong>can</strong> be wrong with the numbers given in the link). Soon after, I disassembled the real hub and counted the teeth of all rings. Here are <strong>the real numbers</strong>. <span id="more-295"></span> This is how the hub works:</p>
<ul>
<li>There are two planet carrierrs. Call &#8220;first&#8221; the one which is closer to the sprocket.</li>
<li>Both rings have two suns, two gears on the planets, and only one ring gear. The ring gear meshes with the smaller gear of the planets.</li>
<li>In lower gears 1 and 2, power input applies to the ring of the first planet carrier. This carrier lowers down the transmission ratio, depending on which sun is locked to the axle by a pawl. The second carrier is not involved.</li>
<li>In higher gears 6 and 7, the first carrier is not involved. Power is applied to the planet ring of the second carrier. Depending on which sun is locked to the axle by a pawl, two step-up ratios are obtained.</li>
<li>In middle gears 3, 4 and 5, both planet carriers are involved.</li>
</ul>
<p>The table explains which exactly rings are engaged, and gives tooth numbers:</p>
<table border="1" cellspacing="0" cellpadding="1">
<tr>
<td>Gear</td>
<td>Power<br />transmission</td>
<td>Sun</td>
<td>Planet<br />meshed<br />with<br />sun</td>
<td>Planet<br />meshed<br />with<br />ring</td>
<td>Ring</td>
<td>Exact<br />ratio</td>
<td>Documented<br />ratio</td>
</tr>
<tr>
<td>1</td>
<td>Ring1->Planets1</td>
<td colspan="2">42</td>
<td rowspan="2">14</td>
<td rowspan="2">72</td>
<td>12/19</td>
<td>0.632</td>
</tr>
<tr>
<td>2</td>
<td>Ring1->Planets1</td>
<td>36</td>
<td>20</td>
<td>20/27</td>
<td>0.741</td>
</tr>
<tr>
<td>3</td>
<td colspan="6">Gears 1 and 6 together</td>
<td>0.843</td>
</tr>
<tr>
<td>4</td>
<td colspan="6">Gears 2 and 6 together</td>
<td>0.989</td>
</tr>
<tr>
<td>5</td>
<td colspan="6">Gears 2 and 7 together</td>
<td>1.145</td>
</tr>
<tr>
<td>6</td>
<td>Planets2->Ring2</td>
<td>30</td>
<td>19</td>
<td rowspan="2">14</td>
<td rowspan="2">66</td>
<td>279/209</td>
<td>1.335</td>
</tr>
<tr>
<td>7</td>
<td>Planets2->Ring2</td>
<td colspan="2">36</td>
<td>17/11</td>
<td>1.545</td>
</tr>
</table>
<p>Note that in the step-up ring (Ring2), 30+19+14=63, while the ring has 66 teeth. Also, 36+14+14=64. I saw one tooth differences between sums of sun and planets and the ring, but at the moment I do not understand how so big difference (3 teeth) can make working combination.</p>
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		<title>Nexus-7 gear tooth counts and exact transmission ratios &#8211; wrong version</title>
		<link>http://www.konstantin.shemyak.com/blog/2009/10/22/nexus-7-gear-tooth-counts-and-exact-transmission-ratios/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2009/10/22/nexus-7-gear-tooth-counts-and-exact-transmission-ratios/#comments</comments>
		<pubDate>Thu, 22 Oct 2009 14:58:07 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[Cycling]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=278</guid>
		<description><![CDATA[ Vendors of internal gear bicycle hubs naturally give the transmission ratios of own products. But I was always curious how exactly these ratios are obtained, i.e. which planet gears are engaged in which combination and how many teeth each gear has. This information was surprisingly hard to find &#8211; in fact, the only vendor [...]]]></description>
			<content:encoded><![CDATA[<p><a href="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/10/ShimanoNexus7.jpg"><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/10/ShimanoNexus7.jpg" alt="ShimanoNexus7" title="ShimanoNexus7" width="320" height="349" class="alignleft size-full wp-image-288" /></a> Vendors of internal gear bicycle hubs naturally give the transmission ratios of own products. But I was always curious how exactly these ratios are obtained, i.e. which planet gears are engaged in which combination and how many teeth each gear has. This information was surprisingly hard to find &#8211; in fact, the only vendor who <a href="http://www.rohloff.de/de/technik/technik_cd/index.html">discloses this is Rohloff</a>! It is certainly possible to just disassemble the hub, but, you know, sitting half-day at the computer screen is more attractive nowadays <img src='http://www.konstantin.shemyak.com/blog/wp-includes/images/smilies/icon_smile.gif' alt=':)' class='wp-smiley' />  I have Nexus-7 hub on one of my bikes, and<strong> I have &#8220;reverse engineered&#8221; the exact tooth counts.</strong><span id="more-278"></span></p>
<p>I found the <a href="http://konstantin.shemyak.com/wiki/images/c/c1/NEXUS_SG-7R40-Werkstatthandbuch.pdf">service instruction in German</a>, explaining which planet rings are transmitting the torque in which gear. This, plus the transmission ratios with three decimal digit precision, plus some general theory proved to be sufficient. <strong>Update:</strong> No! The numbers below are <strong>wrong</strong>. You may think, how this can be seen from them. See <a href="http://www.konstantin.shemyak.com/blog/2009/10/27/nexus-7-exact-ratios-and-tooth-counts-from-the-source">the real counts from the disassembled hub</a> for correct counts.</p>
<p>To understand the numbers below, you must know that Nexus-7 has two planet carriers; each has planets with two bound gears. One of them meshes with the ring gear. Each of planet gears meshes with corresponding sun gear. The latter can be rotating freely, or fixed to the immobile axle with pawls, activated by the shifter. In gears 1 and 2, only the first step-down ring is engaged. In gears 6 and 7, only the second step-up gear is engaged. Read the service instruction linked above for further information.</p>
<p>I give values for the active sun, planet meshed with the sun, planet meshed with the ring, and the ring. Next, the exact fractional ratio is shown, and it&#8217;s decimal value with 5 digits. Last in the line is the 3-digit decimal value from the manuals. We see the rounding errors (and sometimes inconsistencies).</p>
<p style="clear:left;">
First ring, step-down:<br />
<strong>Gear 1:</strong> 31, 17, 22, 69. Ratio: 69 * 17 / ( 69 * 17 + 31 * 22) = 1173 / 1855 ~ 0.63234 ~ <strong>0.632</strong><br />
<strong>Gear 2:</strong> 24, 22, 22, 69. Ratio: 69 / (24 + 69) = 23 / 31 ~ 0.74193 ~ <strong>0.741</strong> </p>
<p>Both rings engaged:<br />
<strong>Gear 3:</strong> G1*G6. Ratio: (1173 / 1855) * (617 / 462) = (17 * 23 * 617) / (2 * 5 * 7^2 * 11 * 53) = 241247 / 285670 ~ 0.84449 ~ <strong>0.843</strong><br />
<strong>Gear 4:</strong> G2 * G6. Ratio: (23 / 31) * (617 / 462) = (23 * 617) / (31 * 2 * 3 * 7 * 11) ~ 0.99085 ~ <strong>0.991</strong><br />
<strong>Gear 5:</strong> G2 * G7. Ratio: (17 / 11) * (23 / 31) =  391 / 341 ~ 1.14663 ~ <strong>1.145</strong></p>
<p>Second ring, step-up:<br />
<strong>Gear 6:</strong> 31, 21, 15, 66. Ratio: 1 + (31 * 15) / (21 * 66) = 617 / 462 ~1.33549 ~1.335<br />
<strong>Gear 7:</strong> 36, 15, 15, 66. Ratio: 1 + 36/66 = 17 / 11 ~1.54545 ~<strong>1.545</strong></p>
<p>The inspiration for this feat was John Allen&#8217;s <a href="http://john-s-allen.com/gears/hubratios.htm">table of tooth counts for various hubs</a>. John did this by some guessing-and-trial-and-error, putting numbers in a spreadsheet with the formulas. Unfortunately his data does not include the two hubs I have, Nexus-7 and Nexus-8. I decided to leave the guessing to the computer and wrote a script, which does exhaustive search over all reasonable combinations. There are two restrictions on numbers of teeth in a working planetary gear (diameters should add up in a known way, and some counts must be divisible by number of the planets for them to be equally spaced; ask me if you want to get techy). Allowing the precision of the resulting ratio down to the last decimal number given in the documentation, the search returned <strong>just one result</strong> for both planet rings of the Nexus! I was so delighted to get such a consistent answer.</p>
<p><strong>Update once again:</strong> this &#8220;consistent answer&#8221; is wrong. <a href="http://www.konstantin.shemyak.com/blog/2009/10/27/nexus-7-exact-ratios-and-tooth-counts-from-the-source">Here</a> is the right one.</p>
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		<title>Difficult elementary school math problems</title>
		<link>http://www.konstantin.shemyak.com/blog/2009/10/02/difficult-elementary-school-math-problems/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2009/10/02/difficult-elementary-school-math-problems/#comments</comments>
		<pubDate>Fri, 02 Oct 2009 18:45:38 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=275</guid>
		<description><![CDATA[Many math problems are fascinating. Often they are also difficult, so that only those who have high enough education can understand their beauty. But sometimes a really simple problem &#8211; such that anyone with just the elementary school knowledge can solve it &#8211; can be quite cute as well. Most elementary school math questions are [...]]]></description>
			<content:encoded><![CDATA[<p>Many math problems are fascinating. Often they are also difficult, so that only those who have high enough education can understand their beauty. But sometimes a really simple problem &#8211; such that anyone with just the elementary school knowledge can solve it &#8211; can be quite cute as well. Most elementary school math questions are truly boring, but it&#8217;s possible to add some spice to this mass.</p>
<p><strong>1</strong> (I knew this earlier) <strong>&#8220;Dried cucumbers&#8221;</strong>:<br />
Cucumber contains 99% of water. A box of cucumbers weighs 100kg. During winter storage, cucumbers dried out so that they now contain only 98% of water. How much does the box weigh now?</p>
<p><strong>2</strong> (I got this today, which inspired me for this post) <strong>&#8220;Probability for doctors&#8221;</strong>:<br />
Assume a test for a rare disease (which affects 1 person in a million) is 99.99% accurate. A patient tests positive. What are the probabilities he actually has the disease?</p>
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		<title>Heavy-duty self-made mudflap</title>
		<link>http://www.konstantin.shemyak.com/blog/2009/09/08/heavy-duty-self-made-mudflap/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2009/09/08/heavy-duty-self-made-mudflap/#comments</comments>
		<pubDate>Tue, 08 Sep 2009 06:45:15 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[Cycling]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=270</guid>
		<description><![CDATA[ Bicycle mudguards are frequently made shorter than they should have been. I was not able to find a front mudguard which would protect front chainrings from water jets pouring from the front wheel.
So I made my own from a 2mm thick rubber sheet. It is heavy and non-aerodynamic. It is heavy-duty! It makes difference [...]]]></description>
			<content:encoded><![CDATA[<p><a href="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/09/diy-mudflap.jpg"><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/09/diy-mudflap-300x250.jpg" alt="Self-made heavy-duty mudflap" title="Self-made heavy-duty mudflap" width="300" height="250" class="alignleft size-medium wp-image-271" /></a> Bicycle mudguards are frequently made shorter than they should have been. I was not able to find a front mudguard which would protect front chainrings from water jets pouring from the front wheel.</p>
<p>So I made my own from a 2mm thick rubber sheet. It is heavy and non-aerodynamic. It is heavy-duty! It makes difference when riding in the rain. It is tested. Highly recommended for bike commuters.</p>
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		<title>Ovi Maps from Nokia: purely ashaming</title>
		<link>http://www.konstantin.shemyak.com/blog/2009/07/12/ovi-maps-from-nokia-purely-ashaming/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2009/07/12/ovi-maps-from-nokia-purely-ashaming/#comments</comments>
		<pubDate>Sun, 12 Jul 2009 16:18:52 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[IT]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=248</guid>
		<description><![CDATA[Nokia has released own online maps, &#8220;maps.ovi.com&#8221;. I have tried this, and found them to be so much inferior to the competitors that I even feel ashamed for its home country (which is now my home country as well). I think in this area Google Maps set the reference, so I&#8217;ve done a small comparison [...]]]></description>
			<content:encoded><![CDATA[<p>Nokia has released own online maps, &#8220;maps.ovi.com&#8221;. I have tried this, and found them to be so much inferior to the competitors that I even feel ashamed for its home country (which is now my home country as well). I think in this area Google Maps set the reference, so I&#8217;ve done a small comparison of the two.<span id="more-248"></span></p>
<p>First of all, what I see when trying to access the site, is this great information:<br />
<img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/07/ovi-maps-does-not-work.png" alt="ovi-maps-does-not-work" title="ovi-maps-does-not-work" width="402" height="387" class="alignleft size-full wp-image-249" /> They kindly inform me that it&#8217;s &#8220;not yet available on UNIX&#8221;. And that I should use Firefox 3. Which I am, in fact, using now. But Ovi does not work anyway. Google maps have been working for my platform with Firefox <strong>already for years</strong>.</p>
<p>The first dumbest thing to do is to use a <a href="https://addons.mozilla.org/fi/firefox/addon/59">user agent switcher add-on</a>, which just tells to the server &#8220;I&#8217;m Internet Explorer&#8221;, and see if that works. What a surprise, it does. So, these Ovi maps just check what my user agent is saying and refusing to serve other agents without visible reason. Disgusting. OK, I still continue.</p>
<div style="clear: left;"><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/07/ovi-maps-margins.png" alt="ovi-maps-margins" title="ovi-maps-margins" width="400" height="438" class="alignleft size-full wp-image-251" clear="left" /> The main screen has&#8230; about 1 cm margins on all sides. What the hell. Screen space is a valuable resource, and everybody wants the map to be larger. In fact that&#8217;s one reason why I still buy paper maps: there is no screen (and certainly no portable screen) which can show as large area in as much detail, as paper map does. Now, they just made my screen 2 cm less in each dimension. I&#8217;m not sure I want to continue. Google does not do that &#8211; <strong> I come for maps, and I get maps. Not white margins.</strong></div>
<div style="clear:left;">These two are the blocking points for me. The Nokia creation is inferior to Google&#8217;s also in other ways:</p>
<ul>
<li>The <strong>density of the map information</strong> is poor. For example, they could put more street titles on the screenshot above, without making it overloaded and crammed. They did not.</li>
<li>The <strong>routing just did not work</strong> for me. Not with the &#8220;unsupported operating system&#8221; &#8211; I tried that under MS Windows. I&#8217;m not interested to dig out, what can I do so that it starts working; Google maps work without any tweaks, and I&#8217;ll use them.</li>
<li>&#8220;Satellite&#8221; and &#8220;terrain&#8221; views did not work. Yea, under the &#8220;supported&#8221; operating system.</li>
<li>I do not see an option to provide a link to the map I&#8217;m looking at now. And this is my frequent use case &#8211; quickly drawing some map and sending it to my companions.
</ul>
<p>I have found only one advantage of Ovi maps: they have better map material for the small roads in Finland (which I&#8217;m mostly interested in for my bicycle rides). Google does not know about track-type roads, Ovi often does. This is an important point for me. Below is the map of the same region from GMaps on the left and from Ovi maps to the right. Note how much more small roads Ovi has. Unfortunately, there is still much to wish; many of these paths are private and closed for access, which it&#8217;s not marked in any way.</p>
<p>Checking other places randomly, I found maps of Lithuania and Russia to be even less satisfactory than the Google&#8217;s ones.
</p></div>
<p><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/07/gmaps-roads.png" alt="gmaps-roads" title="gmaps-roads" width="320" height="333" class="alignleft size-full wp-image-256" /><img src="http://www.konstantin.shemyak.com/blog/wp-content/uploads/2009/07/ovi-roads.png" alt="ovi-roads" title="ovi-roads" width="317" height="331" class="alignleft size-full wp-image-257" /></p>
<div style="clear:left;">
Concerning the mobile version of the application. Nokia is a mobile phone company, so it shall work on phones perfectly, at least on Nokia&#8217;s?</p>
<ul>
<li>I have two Nokia smartphones, E61 and E90. Google mobile maps work <strong>in both devices</strong>. <strong>Nokia</strong> Maps can not be installed in <strong>Nokia</strong> E61 at all.</li>
<li>Google maps show your approximate location based on the serving cell when the GPS is not available. Nokia maps do not.</li>
<li>Google maps start up so much faster than Nokia&#8217;s.</li>
<li>Google maps have &#8220;public transportation&#8221; feature. Way cool for me.</li>
</ul>
<p>To be fare, here is an advantage of Nokia mobile maps, which is important in some cases: maps can be downloaded to the phone and used offline. So, in the field, they work faster, and do not consume two valuable resources: battery power and money for the data transfer. But, what a surprise: you need MS Windows with installed Nokia software for that. So you can&#8217;t do it with just a phone, or at your friend&#8217;s home. [Oh what a happiness, it fact this can be done, bypassing the official Nokia instructions; <a href="http://diabo.110mb.com/symbian/nokiamaps/maps00_01_22_103.html">read this</a>.]
</div>
<p><strong>My message to Ovi managers:</strong> you are not only several years behind in time. You are also way behind in the implementation. I don&#8217;t see how you are going to catch up.</p>
<p>And, sure, I&#8217;m not working on either of the companies I compare.</p>
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		<title>Welcome to Vantaankoski evening rides</title>
		<link>http://www.konstantin.shemyak.com/blog/2009/06/26/welcome-to-vantaankoski-evening-rides/</link>
		<comments>http://www.konstantin.shemyak.com/blog/2009/06/26/welcome-to-vantaankoski-evening-rides/#comments</comments>
		<pubDate>Fri, 26 Jun 2009 07:56:29 +0000</pubDate>
		<dc:creator>konstantin</dc:creator>
				<category><![CDATA[Cycling]]></category>

		<guid isPermaLink="false">http://www.konstantin.shemyak.com/blog/?p=245</guid>
		<description><![CDATA[Living in Helsinki region, looking for a company for evening sporty road rides? Come to Vantaankoski (the home mark on the map below) on Tuesdays and Thursdays by 18:00.
What to expect there?  A sporty ride for 2-3 hours; this time we rode 87km in 2:40h, which makes 32.8km/h average. 
View  in a larger [...]]]></description>
			<content:encoded><![CDATA[<p>Living in Helsinki region, looking for a company for evening sporty road rides? Come to <strong>Vantaankoski</strong> (the home mark on the map below) on Tuesdays and Thursdays by 18:00.</p>
<p>What to expect there? <span id="more-245"></span> A sporty ride for 2-3 hours; this time we rode <strong>87km</strong> in <strong>2:40h</strong>, which makes <strong>32.8km/h</strong> average. </p>
<p><iframe width="320" height="420" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="http://maps.google.com/maps/ms?ie=UTF8&amp;hl=en&amp;msa=0&amp;msid=118397091897014227191.00046d3ad314a406de3ef&amp;ll=60.404358,24.934845&amp;spn=0.284859,0.439453&amp;z=10&amp;output=embed"></iframe><br /><small><a href="http://maps.google.com/maps/ms?ie=UTF8&amp;hl=en&amp;msa=0&amp;msid=118397091897014227191.00046d3ad314a406de3ef&amp;ll=60.404358,24.934845&amp;spn=0.284859,0.439453&amp;z=10&amp;source=embed" style="color:#0000FF;text-align:left">View  in a larger map</a></small></p>
<p>Almost 33km/h average speed may sound too sporty for many. But it&#8217;s a group ride, and the power for 33km/h in draught is comparable to maybe 27.5-28km/h average alone. Also, the group motivates! I&#8217;m unlikely to pedal the same distance even at 27.5km/h average because of my lack of motivation &#8211; I need a reason to push myself. When there are 15 persons hanging around, I need a reason to drop out. Sometimes there is one (too fast! <img src='http://www.konstantin.shemyak.com/blog/wp-includes/images/smilies/icon_smile.gif' alt=':)' class='wp-smiley' />  ), but now I holded until the end. Of course there is absolutely no problem if anyone wants to stop or continue own way &#8211; just inform somebody in the head so that others do not think that you have some technical problem and do not stop to wait.</p>
<p>It was sunny, dry, and a bit over +20&deg;C. We do not have that good cycling weather too often in Finland, so it must be used effectively!</p>
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