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Everything posted by Sensei
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Blocking Strangers From Following Me
Sensei replied to iNow's topic in Suggestions, Comments and Support
That looks very suspicious... If somebody truly wants to just read the all messages that you posted, you can't do anything with it because in the worst scenario he or she will write crawler/harvester which will visit person profile every couple minutes or seconds (script with wget/curl in a loop), parse it, and check if sonebody wrote anything new and then parse new messages and add to the database. ps. Beware of attaching photos. Remove meta-data from photos. Don't add photos from smartphone on mobile version of this site directly! Use PC. You have no idea what meta-data they contain! Always check them if you took photo. The details of the device, once automated (with millions other photos), also can be used for identification and tracking. ps2. Beware of attaching links from newsfeed or links from search engine etc. They have your personal GUID (global unique identifier) to track you and activity ("xxx was shared by yyy number of people" there is such field on FB). Always remove query string to absolute minimum (on mobile it is very unpleasant job).. -
Distance depends on air polution, humidity, fog, dust etc. Water and other particles disperse light in the all directions randomly. In vacuum there is not enough particles to scatter photons thus we can see light from distant stars..
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How many quarks in a proton?
Sensei replied to Curious layman's topic in Modern and Theoretical Physics
What is missing, but a key essential element (including this thread), in the Standard Quark Model there are "valence quarks" i.e. those that contribute to the total Baryon Number, and other quantum numbers, and those that are not valence quarks (they cancel out their quantum numbers with their antiparticles). https://en.wikipedia.org/wiki/Quark_model Some people/scientists simply skip word "valence", taking it as granted, while talking about "the number of quarks in composite particle". -
Here you have nice explanations of various types of manometers with images: https://www.engineeringclicks.com/manometer/
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Experimentally.. e.g. have thermometer and manometer. Increase temperature with fixed volume (closed container) and observe readings from manometer..
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Does absolute measurement only exist in the mind?
Sensei replied to Alex Mercer's topic in Other Sciences
The same like with my quantum scale decay example - some rivers appear, some rivers occasionally disappear, e.g. rain/dry weather and their quantity changes.. -
Does absolute measurement only exist in the mind?
Sensei replied to Alex Mercer's topic in Other Sciences
Quantity of objects is exact integer number (unless multiverse or parallel universes are introduced). At quantum level everything changes and do it very fast in human terms. One measurement you have neutron, in another you may have decay of unstable isotope in which neutron was part of nucleus, and your previous measurement no longer represents current state.. -
Oncogenes do not cause cancer. They just have the potential to cause cancer. that is, after severe code damage during replication, it may prevents programmed cell death. For me thread title sounded more like you are interested in "genetic disorder", "genetic disease", not "cancer".. Damage of the code done several generations ago, which spread to organim offspring. https://en.m.wikipedia.org/wiki/Genetic_disorder To some extent genetic disorders are fixable by specially prepared viruses which will inject the corrected genetic material into existing cells and fix the problem. Such therapy is extremely expensive, counted in hundred thousands or millions USD, per person, and only the richest people can afford it, for the rest there is needed crowdfunding.. https://en.m.wikipedia.org/wiki/Viral_vector https://en.m.wikipedia.org/wiki/Oncolytic_virus
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..but OP didn't say the answer should be in Python...
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Hangman game? In two weeks? Your teacher is very gracious.. ps. If you will write it in 60 minutes, you will be spared..
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Where is the core principles that govern mathematics?
Sensei replied to Alex Mercer's topic in Mathematics
In textbooks? -
Does stereotypical nerd or geek exists?
Sensei replied to CurseNight102's topic in Psychiatry and Psychology
Nerds and geeks are not antisocial. They simply don't want to waste their time on talking with lower form of intelligence i.e. people who mock of them.. Nerds and geeks are spending time with other nerds and geeks. Likewise people understand each other, have common worldview, have common subjects for discussions etc. etc. -
Regardless of source of data there are stock operations like stock split and stock merge which dramatically change stock price when in the reality they are neutral . Read here: https://en.m.wikipedia.org/wiki/Stock_split https://en.m.wikipedia.org/wiki/Reverse_stock_split Which will completely confuse script or program which doesn't handle them or stock data doesn't contain information about the operation. E.g. one day stock price is $100 and the next day is $20. Script will interpret it as 80% drop of price when in the reality there was no drop but quantity of shares was 5x multiplied. Yet another operation influencing price is dividend. Read here: https://en.m.wikipedia.org/wiki/Dividend
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Are you against shale gas and fracking technology only? Or against drilling tradidional way natural gas too? In your posts you are mixing them. 39 mln tones worldwide is leakage from both technologies. Fracking is minority of worldwide production of gas. Contrary to US were it is dominant technology. (People in US are often forgetting that World is not only US..) Decide if you want to talk about US or World. Don't mix World data with US data. Keywords for search engine "natural gas market share" "shale gas market share". https://www.eia.gov/todayinenergy/detail.php?id=27512
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It is easy to dismiss it as "prime trigger of global warming". Anthropogenic methane emissions worldwide in 2019 was 363 mln tons. 33% of it was coal, oil and gas production, distribution and usage. USA had 6.2% share of methane emissions in 2012. In 1970 it was over 11%. (in absolute numbers it also dropped). See table in below article. https://en.m.wikipedia.org/wiki/Methane_emissions Coal, oil and gas industry by themselves should be the most interested in methods limiting leakage of methane because they simply can't sell leaked product to end customers and lose money. If entire US would stop coal, oil and gas production and usage (regardless of whether it is using fracking or not), methane emissions worldwide would drop only by 2%. Attempt to fight with anthropogenic global warming is job of entire worldwide population, not just one country, or group of countries. Personally I think attempt to fight with it by taxation is silly and instead of solving existing problems, it makes new ones, economical e.g. movement of investors to countries without this silly CO2 emission tax. Which ends up with people being fired (unhappy and rejecting AGW), production unprofitable, reduction of country export (higher costs of production) etc. etc.
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If aim is to have Deuterium, search net how to make heavy water. Once you have heavy water you can just do electrolysis of water. Typical source of Hydrogen in lab is electrolysis of water. Normal tap water has very little amount of Deuterium. Sea water has a bit more. Search net for "abundance of Deuterium". It is 1 per 6400. So there are three possible combinations H2, DH and D2. H2 is the most abundant and D2 is the least abundant. Similar situation is with water. There are three combinations H2O, HDO and D2O. From normal water you make semiheavy water and then semiheavy water is enriched to heavy water. https://en.m.wikipedia.org/wiki/Semiheavy_water From more info read production of the heavy-water https://en.m.wikipedia.org/wiki/Heavy_water
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Artificial Intelligence with n-gram(Python 2.7 (64 bits) Scripts)
Sensei replied to fredreload's topic in Computer Science
Caching thousands the most used words in ASCII would take a few dozen kilobytes. Not MB. Not GB. But KB. In Unicode 2-4x more. You are caching to not have to lookup things like "I", "you", "it", etc. etc. -
Artificial Intelligence with n-gram(Python 2.7 (64 bits) Scripts)
Sensei replied to fredreload's topic in Computer Science
Make cache in memory. Check if word is present in dynamically allocated array or key-value pair associative array, if it is, increase usage counter of the entry. If it is not present, lookup the database and put the new entry in the cache. Have 1000, 10000, or so, the most used entries. From time to time flush cache of the least used entries. The most frequently used words-entries-phrases will be cached at all times during execution of the script. You can make separate caches for words, phrase with two words. three words. Each with user configurable max number of entries. In OOP language you should just make class for cache which will cover entire database code. -
Artificial Intelligence with n-gram(Python 2.7 (64 bits) Scripts)
Sensei replied to fredreload's topic in Computer Science
Do you have SSD? Do you have NVMe? What is transfer of data during db access? How many GB of memory does your computer have? Try using virtual disk in memory to see whether there will be change in speed. How are you storing, querying and updating db? Show SQL query string for them all. You can try: - calculate md5 (or so) of phrase text first. It will be hash code. - phrase table. Use above hash as unique key together with each phrase text. - frequency table. Use above hash code in second table with quantities / frequencies as integer. Therefore update should be faster. Won't require adding or replacing entire string. Alternatively don't store phrases as plain text. Have dictionary with words with unique indices. 4 bytes integer is enough to have 4.2 bln words. Then make phrase dictionary table. One with two columns for word indexes. Second table with three columns for word indexes. etc. in the future you will add more. -
@MigL You can't /shouldn't trash old CDs, DVDs, HDDs, pendrives, computers, laptops, tablets, smartphones, anything with your personal data. Especially if they were damaged. E.g. many people thoughtlessly throw away a smartphone with a cracked screen. If the device will be intercepted by a competent person such as a hacker, he/she will fix it and get the all data from it. Possible consequences are stolen identity, yours, a family member or other person (do you have contacts in smartphone with phone numbers and emails? content of emails with long discussion about private subjects). If you can't remove data storage from a device e.g. smartphone or table, you shouldn't use electronic repair service either if you can't see entire process personally. If a hacker works in a repair service, they will get your personal data. You can get an unwanted unauthorised loan, interception of bank accounts, and similar accidents..
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Paper is made of wood. Freshly cut tree contains trace amount of radioactive isotope of Carbon C-14 with half life ~ 5730 years. https://en.m.wikipedia.org/wiki/Carbon-14 There is aluminum foil in each kitchen. It is used to cover cakes in the oven. You can buy it at almost any grocery store around the corner.
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Grow up my child, grow up..
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Repeat the question after 10, 15 or 20 years when there will be no working CD/DVD reader/writer anymore. Who cares about UV light? Write 10+ copies of the same files with checksums every 1 kb or so. If you will have in 2030-2040 working reader which will work with PC you will be able to recover data from 10 copies.. but most likely your readers will be broken and modern in 2030-2040 PC won't allow plugging ancient CD/DVD readers anymore..
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If you are concerned about the safety of data storage after years, you should answer the question of whether you are able to load data from a tape recorded in the 80's or 90's... In my laptop there is no built-in CD/DVD reader at all.. (in my PC I don't have it either plugged all the time) Do you have it in your laptop? It increases weight of the device therefore it is used less and less.. Do you have external CD/DVD reader/writer? Soon it will be hard to get them at all. Like tapes. Or similar things from the past years.