question_id string | site string | title string | body string | link string | tags list | votes int64 | creation_date timestamp[s] | comments list | comment_count int64 | category string | diamond int64 |
|---|---|---|---|---|---|---|---|---|---|---|---|
401 | dsp | a moving average relation that I can't find a counter-example to | Hi: I'm new to this list but I had a question that's not exactly related to dsp but maybe in a slight way and I didn't know where else to send it. So, here goes and my apologies if this is totally the wrong place to send it.
The following describes the background as far as number generation.
Suppose have a series of... | https://dsp.stackexchange.com/questions/9915/a-moving-average-relation-that-i-cant-find-a-counter-example-to | [
"algorithms"
] | 5 | 2013-07-12T06:20:42 | [
"also, a different explanation of the same problem is in the article at arxiv.org/abs/1212.4890. it's very long but might be clearer. thanks again.",
"sorry jason. my mistake. it should read that $winnum = log(x_{tstarstar})−log(x_{tstar})$. thank you for pointing that out.",
"The above description of your game... | 3 | Technology | 0 |
402 | mattermodeling | Contribution in action from collisions for a gas? | So if I write the [action](https://en.wikipedia.org/wiki/Action_\(physics\)) for a gas:
$$ S = \int (T -U) dt \tag{1}$$ where $T$ is the kinetic energy and $U$ is potential energy.
I suspect there is a constant term (which does not affect the equations of motion) for the gas (in classical mechanics). I was hoping to ... | https://mattermodeling.stackexchange.com/questions/8498/contribution-in-action-from-collisions-for-a-gas | [
"molecular-dynamics",
"thermodynamics"
] | 8 | 2022-01-07T07:08:23 | [
"(by linking to your paper you are now Less Anonymous :)"
] | 1 | Science | 0 |
403 | puzzling | REALLY important days in history | @Z. Dailey asks a mathematical puzzle [Important days in history... and to come!](https://puzzling.stackexchange.com/questions/29503/important-days-in-history-and-to-come) with a series of dates in years 1973, 1978, 1983, 1992, 2005.
My puzzle asks the question: What is the previous date in my series? Explain!!
... | https://puzzling.stackexchange.com/questions/29533/really-important-days-in-history | [
"knowledge",
"pattern",
"number-sequence",
"sequence",
"history"
] | 22 | 2016-03-24T02:41:27 | [
"I'm assuming it's not January 3, 1972 and April 1, 1975...",
"@Haobin Is the hint in any way related to the Lufthansa logo?",
"Nothing failed about it. Also it's valid from a math p.o.v. ;check the MM/DD also.",
"@Overmind I would question your failed conclusion.",
"Logic dictates there's a high chance tha... | 7 | Culture & Recreation | 1 |
404 | puzzling | Can you find the cipher that I used? | I have encoded a phrase, using a cipher that I invented. But I don't want you to decode it, rather I want you to figure out how my cipher works.
This is the phrase that I encrypted
> Find the connection between this phrase and the output. You don't even have to do any solving, just figure out how this was encrypted
... | https://puzzling.stackexchange.com/questions/96886/can-you-find-the-cipher-that-i-used | [
"cipher"
] | 11 | 2020-04-09T08:43:03 | [
"That's much better, nice job! +1."
] | 1 | Culture & Recreation | 0 |
405 | puzzling | A Glutton and a Split Check | **N** , **T** , **A** , **B** are arbitrary constants in this problem. I have only definitively solved the **N=1** subproblem, so, if the general problem cannot be solved, I will be satisfied to mark as accepted a solution to this subproblem. I may put a bounty out for the general solution before that.
## Problem Stat... | https://puzzling.stackexchange.com/questions/111330/a-glutton-and-a-split-check | [
"mathematics",
"strategy",
"game-theory"
] | 9 | 2021-08-16T15:49:43 | [
"@Feryll Ah sorry, missed that N was your friends, not the number of people at the table. I see now the problem statement clarifies that. Thanks!",
"You have N friends, so, there are N+1 people in total who have precommitted to splitting the $T check. What they have not decided in advance is who is ordering what.... | 9 | Culture & Recreation | 0 |
406 | puzzling | Who wins the game of "Sticky Gomoku" on an infinite board? | This is a [Gomoku](https://en.wikipedia.org/wiki/Gomoku) like game, played by two players with Go pieces (black and white stones) on an infinite (in all four directions) Go board.
Rules
1. **Four in a row:** players alternate turns placing a stone of their color on an empty intersection. Black plays first. The winn... | https://puzzling.stackexchange.com/questions/112346/who-wins-the-game-of-sticky-gomoku-on-an-infinite-board | [
"game",
"board-games"
] | 7 | 2021-10-28T02:56:16 | [
"@Eric I see, thanks for the clarification! I guess it would be very hard to solve, as one doesn't expect to find a finite game tree that totally describes optimal moves.",
"@WhatsUp I heard of this game from an internet friend, who allegedly had invented it a few years ago, and had played it with friends since. ... | 7 | Culture & Recreation | 0 |
407 | puzzling | Best moves for a 7X7 4 queen board | There is a 7x7 board and 2 players, each having 2 queens. The queens can move just like the queens in chess, but cannot capture each other. At the beginning, the first player places both the queens on any 2 different squares. Then the second player does the same with his queens. From this point, the players alternate t... | https://puzzling.stackexchange.com/questions/59804/best-moves-for-a-7x7-4-queen-board | [
"board-games"
] | 7 | 2018-01-25T21:09:16 | [
"@SuhailGupta I hope that this answers most of your doubts. [1]:",
"didn't read the \"can't move across\" part sry, so I guess they can't.",
"@Untitpoi How does it matter?",
"If I have two queen in A1 and B1 can I make the queen in A1 move into C1? At the same time I choose to move my queen in B1 in C3!... | 13 | Culture & Recreation | 0 |
408 | puzzling | What is a 255b Word™? | This is in the spirit of the [What is a Word/Phrase™](https://puzzling.stackexchange.com/search?q=%22what+is+a%22+word+is%3Aquestion) series started by [JLee](https://puzzling.stackexchange.com/users/463) with a special brand of [Phrase™](https://puzzling.stackexchange.com/search?q=%22Phrase%22%20user%3A463%20is%3Aques... | https://puzzling.stackexchange.com/questions/92184/what-is-a-255b-word | [
"steganography",
"computer-puzzle",
"word-property"
] | 7 | 2019-12-22T04:56:24 | [
"@Jasen Yes, both are correct.",
"are both lists correct?",
"@Vepir Yeah, I deliberately misspelled a few letters in CSV. :)",
"Is the CSV misspelled? (\"DECENT'H'ALIZATION\" with 'H' in CSV, but with 'R' in the table) Is CSV purposely not fully capitalized? (such as 'g' in \"KNOWLED'g'EABLE\" and 'l' in \"C... | 4 | Culture & Recreation | 0 |
409 | puzzling | Need help with a cipher: "poems" with capital letters | I am trying to figure out a cipher I _think_ I found in a book from 1982 and it's a 36 year old mystery we are trying to solve (I will reveal the book if this turns out to be something so everyone can play along!). The book has several poems in it that has has lines that start with capital letters. There is also severa... | https://puzzling.stackexchange.com/questions/53173/need-help-with-a-cipher-poems-with-capital-letters | [
"cipher",
"real",
"unsolved-mysteries"
] | 6 | 2017-07-05T14:13:38 | [
"thesecret.pbworks.com/w/page/22148585/To%20Do",
"@Rubio As far as I can tell no one has come up with this cipher. I believe the only ones that are important are the first letters (besides using the clues in the verse to guide you too) as part of a secret cipher for several reasons.Preiss doesn't give us a way i... | 6 | Culture & Recreation | 0 |
410 | puzzling | Rare but Abundant in Hill and Hole | > I am uncommon,
> But a worthy goal.
> Rare but abundant
> In hill and hole.
> Who am I?
You may already know the answer, so the task is not to answer the riddle per se, but to solve the following 'What is a Word' puzzle, use the words in the puzzle to find another four word phrase (2 from each side), and... | https://puzzling.stackexchange.com/questions/109321/rare-but-abundant-in-hill-and-hole | [
"riddle",
"word",
"pattern",
"word-property",
"letters"
] | 6 | 2021-04-07T21:21:04 | [] | 0 | Culture & Recreation | 0 |
411 | cs | Can a calculus have incremental copying and closed scopes? | A few days ago, I proposed the [Abstract Calculus](https://medium.com/@maiavictor/the-abstract-calculus-fe8c46bcf39c), a minimal untyped language that is very similar to the Lambda Calculus, except for the main difference that substitutions are `O(1)` (i.e., variables only occur once) and copying is an explicit, consta... | https://cs.stackexchange.com/questions/96798/can-a-calculus-have-incremental-copying-and-closed-scopes | [
"lambda-calculus",
"type-theory",
"functional-programming",
"language-design"
] | 24 | 2018-08-27T17:09:19 | [
"@chi I was reading Lamping's original paper right now, seems like he doesn't propose a textual calculus indeed. What I proposed is just a textual interpretation of his algorithm (in any of its stages). That representation can itself can be considered a calculus with 4 reduction rules, but requires abandoning the n... | 6 | Science | 0 |
412 | cs | Is the two-color leapfrog problem in P? | My question is whether a specific decision problem is in P or not. It's straightforwardly in NP. The decision problem is a specific case of the general $k$-color leapfrog problem.
I can already show that when $k=1$, the problem is in P. And when $k$ is unlimited, the problem is NP-complete. I have not been able to fin... | https://cs.stackexchange.com/questions/127611/is-the-two-color-leapfrog-problem-in-p | [
"complexity-theory",
"turing-machines"
] | 18 | 2020-06-24T01:51:59 | [
"A case is a set of additional constraints that we might choose to impose. E.g., \"Is there a solution in which urns 3 and 5 finish with at least 1 A-ball each, and urns 2 and 5 finish with at least 1 B-ball each?\" The idea being to come up with a set of at most polynomially many cases such that (a) any solution t... | 14 | Science | 0 |
413 | cs | Test whether two languages are equal, when give in algebraic form | This sub-problem is motivated by [Algorithm to test whether a language is regular](https://cs.stackexchange.com/q/18010/755).
Suppose we have two languages $L_1,L_2$ that are expressed in "algebraic" form, as formalized below. I want to determine whether $L_1 = L_2$.
Is this decidable? If yes, can anyone suggest an a... | https://cs.stackexchange.com/questions/18062/test-whether-two-languages-are-equal-when-give-in-algebraic-form | [
"algorithms",
"formal-languages",
"regular-languages",
"decision-problem"
] | 15 | 2013-11-15T19:08:21 | [
"If it is limited to regular languages, then you can compare them. Regular languages can be converted to finite state machine. And if you minimise two different finite state machines and you end up with the same answer for both, then they are infact the same. (They both handle the same language if they simplify to ... | 4 | Science | 0 |
414 | cs | What can be proven regarding the differences in power between unary ECMAScript regex functions and primitive recursive functions? | In 2014, inspired by [Regex Golf](https://alf.nu/RegexGolf), I started exploring, along with a mathematician going by the name **teukon** , what could be done in the unary domain in ECMAScript regex that went significantly beyond matching primes and powers of 2 (both of which were puzzles in the Regex Golf site). This ... | https://cs.stackexchange.com/questions/137112/what-can-be-proven-regarding-the-differences-in-power-between-unary-ecmascript-r | [
"complexity-theory",
"computability",
"space-complexity",
"number-theory",
"primitive-recursion"
] | 14 | 2021-03-25T14:34:10 | [
"@Nayuki That logic doesn't work. The equivalent of only a finite number of digits of the transcendental number need to be calculated. By your logic, it wouldn't even be possible in a Turing-complete language to take a natural number N as input and calculate the first N digits of pi as output, but that is possible.... | 2 | Science | 0 |
415 | cs | Choosing a subset of binary variables to maximize the sum of the highest $K$ | Consider the following problem:
**Input:**
* integers $n > m > k$;
* $n$ numbers $0 \leq p_1, \ldots, p_n \leq 1$;
* $n$ numbers $r_1, \ldots, r_n$ where ($r_i \geq 0$).
Let $X_1,\dots,X_n$ be $n$ independent random variables with distribution $X_i \sim \text{Bernoulli}(p_i)$ and define $Y_i = r_iX_i$.
**Ou... | https://cs.stackexchange.com/questions/37294/choosing-a-subset-of-binary-variables-to-maximize-the-sum-of-the-highest-k | [
"algorithms",
"complexity-theory",
"probability-theory"
] | 13 | 2015-01-16T13:41:23 | [] | 0 | Science | 0 |
416 | cs | Covering a complete graph with n copies of an arbitrary graph: NP-complete? | > Given a complete graph $G$, an arbitrary graph $H$, and a positive integer $n$, are there subgraphs $A_1,\dots,A_n$ of $G$ (not necessarily disjoint) such that their union is $G$, and each of them are isomorphic to $H$?
This is a problem which I believe is NP-complete, but I am unsure if it is actually so. Any ideas... | https://cs.stackexchange.com/questions/89221/covering-a-complete-graph-with-n-copies-of-an-arbitrary-graph-np-complete | [
"algorithms",
"complexity-theory",
"graphs",
"np-complete"
] | 12 | 2018-03-11T15:07:57 | [
"Do you mean a subgraph by a subgraph induced by a subset of vertices of $G$ (which is the definition used in subgraph isomorphism problem)? How do you define the union of two subgraphs?",
"Another special case that looks hard (an open problem since 1967) is when $H$ is a collection of vertex-disjoint cycles: en.... | 4 | Science | 0 |
417 | cs | Is extensionality for coinductive datatypes consistent with Coq's logic? | Given a coinductive datatype, one can usually (always?) define a bisimulation as the largest equivalence relation over it. I would like to add an axiom stating that if two members of the type are related by the bisimulation, they are equal in the sense of Leibniz equality (`=`). Would this make the logic inconsistent?
... | https://cs.stackexchange.com/questions/63197/is-extensionality-for-coinductive-datatypes-consistent-with-coqs-logic | [
"coq",
"equality",
"coinduction"
] | 12 | 2016-09-06T08:12:19 | [
"The last paragraph of section 2.2.2 of Simon Boulier's PhD thesis \"Extending type theory with syntactic models\" (tel.archives-ouvertes.fr/tel-02007839) states that it is provable in a univalent setting, if you use a well-chosen definition of stream, and gives references.",
"@paulotorrens No -- I still believe ... | 3 | Science | 0 |
418 | cs | Regularity profiles | A standard exercise in formal language theory uses [Lagrange's four-square theorem](https://en.wikipedia.org/wiki/Lagrange%27s_four-square_theorem) to construct a language $L$ such that $L$ isn't regular but $L^2$ is regular. (Let $A = \\{ a^{n^2} : n \geq 0 \\}$. Then $A$ isn't regular, but $A^4 = \\{ a^n : n \geq 0 \... | https://cs.stackexchange.com/questions/113326/regularity-profiles | [
"regular-languages"
] | 11 | 2019-09-02T07:08:40 | [
"@BaderAbuRadi I'm not aware of any progress on these questions, though I'm not sure I would know. Nobody contacted me regarding them.",
"Yuval, do you have an idea if these questions have been studied yet, or did they remain open?"
] | 2 | Science | 0 |
419 | cs | (Slightly) faster simulation of quantum Fourier transform | Suppose I want to write a classical software simulator of a quantum circuit with $N$ qubits. When it comes time to simulate the quantum Fourier transform I can evaluate all $2^N$ states to determine the probability amplitudes, and then perform a Fast-Fourier Transform on the probability amplitudes in time $o(N 2^N)$. F... | https://cs.stackexchange.com/questions/13325/slightly-faster-simulation-of-quantum-fourier-transform | [
"randomized-algorithms",
"quantum-computing",
"fourier-transform"
] | 11 | 2013-07-17T20:50:14 | [
"suggest migrate to Theoretical Computer Science"
] | 1 | Science | 0 |
420 | cs | Change in the distances in a graph after removal of a node | Given an undirected unweighted graph $G=(V,E)$ and a node $s \in V$, we are looking for a vector $\operatorname{diff}[]$, such that,
$$\operatorname{diff}[v] = \sum_{u \in V \setminus \\{v\\}}{(d^{G \setminus \\{v\\}}_{su}-d^G_{su})}$$
In other words, we are looking for the difference in distances from $s$ to every ... | https://cs.stackexchange.com/questions/29746/change-in-the-distances-in-a-graph-after-removal-of-a-node | [
"algorithms",
"graphs",
"shortest-path"
] | 11 | 2014-09-07T20:47:48 | [
"@FrankW If that distance goes through a child, then it will be the minimum is the first term $diff[v']+1$.",
"there are at least 3 papers by Camil on that page, & online paper links are not given so far. the papers generally look at adding/ removing vertices/ edges.",
"@vzn The paper by Camil investigates edge... | 4 | Science | 0 |
421 | cs | Minimum edge deletion partitioning of a planar graph | I'm interested in the time complexity of the following problem:
Given an undirected _planar_ graph $G=(V,E)$ and a weight function $w:E \rightarrow \mathbb{Z}$ (so weights can be negative, too), color the vertices in such a way that the sum of the weights of the monochromatic edges (i.e. those between same color verti... | https://cs.stackexchange.com/questions/45731/minimum-edge-deletion-partitioning-of-a-planar-graph | [
"complexity-theory",
"graphs",
"np-hard",
"weighted-graphs"
] | 11 | 2015-08-31T06:00:04 | [
"If you restrict the number of colors to 2, then the problem is equivalent to max-cut (with possibly negative edge weights), which is NP-hard for general graphs but solvable in polynomial time for planar graphs. So maybe planarity could help here as well.",
"The interesting property of planar graphs in this conte... | 5 | Science | 0 |
422 | cs | When can you "invert" an equation in the lambda calculus | Suppose that $M$ is a full model of the simply typed lambda calculus. Suppose each base type is infinite.
Now suppose that $f$ and $g$ are two functions in $M$ (not necessarily in the same domain) that are not definable by any pure term, and that $\alpha$ is a pure term of the $\lambda$-calculus such that: $$M(\alpha)... | https://cs.stackexchange.com/questions/57786/when-can-you-invert-an-equation-in-the-lambda-calculus | [
"lambda-calculus",
"combinatory-logic"
] | 11 | 2016-05-23T18:15:31 | [] | 0 | Science | 0 |
423 | scifi | Novel about an immortal man exposed by world government relates his life through history | I read the book from my local library in the early- to mid- seventies. It was hardcover (library bound) and the dust jacket had a printed burlap or canvas background. The back flap mentioned that the author's name was a pseudonym. The book had lots of conversation, anecdotes and opinions with little to no 'action'. I c... | https://scifi.stackexchange.com/questions/66361/novel-about-an-immortal-man-exposed-by-world-government-relates-his-life-through | [
"story-identification",
"novel",
"immortality"
] | 59 | 2014-08-23T20:23:52 | [
"The part about the protagonist being thousands of years old eliminates the novel Operation Longlife by E. Hoffmann Price. Doc Brandon, an obvious knockoff of the pulp hero Doc Savage, was less than two centuries old when the government realized he'd somehow stumbled across a method of keeping himself young and fit... | 10 | Life & Arts | 1 |
424 | scifi | Looking for science fiction assassination story with mysterious girl | For years I've been looking for a short science fiction story about a man who was released from a prison planet in order to assassinate a candidate for galactic president. He does this on a space station, and escapes with the help of a mysterious and very attractive girl with silvery hair and multi-colored skin.
I rea... | https://scifi.stackexchange.com/questions/27694/looking-for-science-fiction-assassination-story-with-mysterious-girl | [
"story-identification",
"short-stories"
] | 55 | 2012-12-06T11:39:59 | [
"Jupiter Ascending? Which is a 2015 film, and not a short story I read somewhere in the early 2000s. I saw that film, and never even noticed any common plot elements. Sorry.",
"Sounds like Jupiter Ascending (imdb.com/title/tt1617661).",
"Aspects remind me of Spinrad's \"Agent of Chaos\". But that was a full n... | 8 | Life & Arts | 0 |
425 | scifi | Story about man unable to wake up from dream | I am looking for a story which I read a long time back but cannot recall the name. The plot line was:
In a futuristic world, there are dream parlors which provide sleep with dream services. The protagonist is a frequenter of them.
One day, it was found that he is unable to wake up after slipping into a dream. All e... | https://scifi.stackexchange.com/questions/117737/story-about-man-unable-to-wake-up-from-dream | [
"story-identification",
"dreams"
] | 43 | 2016-02-08T02:42:15 | [
"Sounds like a good story... Were there aliens/robots or anything?",
"Damn, I have read this before, but I cannot for the life of me remember the name of the story. I think it was a short story from an anthology by Heinlein, but I can't say for sure.",
"When was \"a long time ago\"? You may not remember exactl... | 3 | Life & Arts | 0 |
426 | scifi | A space story about a desert planet and a cup of water | I read this story over 15 years ago. It is probably a lot older. I read it in Serbian magazine (Politikin Zabavnik) but I think that the language of the original is in English. It's a short story, less than two A4 formats long.
The story as I remember it is as follows:
A young man/boy (crash)lands on a desert planet.... | https://scifi.stackexchange.com/questions/79870/a-space-story-about-a-desert-planet-and-a-cup-of-water | [
"story-identification",
"short-stories"
] | 42 | 2017-09-28T09:16:06 | [
"It was a kid's story-they read it to us in class back in the 2nd or 3rd grade-so this would put the book at least before 1990, if that helps anyone"
] | 1 | Life & Arts | 0 |
427 | scifi | Futuristic world where reality is humanity's plaything and God is in a zoo | This is a novel I read in 2015. It was an older book. The cover was black and hardcover. Don't remember any specific details. The book was in English. I believe it was from the 1980s or ‘90s.
It was set in the future where the world is united as one.
I'll try to outline all the major events that I remember, in as mu... | https://scifi.stackexchange.com/questions/203664/futuristic-world-where-reality-is-humanitys-plaything-and-god-is-in-a-zoo | [
"story-identification",
"novel",
"genetic-engineering"
] | 39 | 2019-01-17T20:42:52 | [
"@NeoDarwin Does anything in this question of mine sound familiar? scifi.stackexchange.com/questions/14510/…",
"Reality anchor is in quotes because it had a complicated name. It's purpose was to anchor reality.",
"This got nothing",
"It is not this book",
"Very confident. I read it only 3 years ago and have... | 8 | Life & Arts | 0 |
428 | scifi | Old SF novel, set on a military ship, one character can't order spaghetti and meatballs because of sudden mid-voyage rationing? | This one is a real longshot. I won't be surprised if nobody can identify it. I read this book sometime in the early-to-mid-1980s. Science fiction novel, checked out from a public library, written in English, and I am pretty sure it was in hardback. Told in the third person, with multiple viewpoint characters, and a fai... | https://scifi.stackexchange.com/questions/145076/old-sf-novel-set-on-a-military-ship-one-character-cant-order-spaghetti-and-me | [
"story-identification",
"spaceship"
] | 36 | 2016-11-13T18:07:05 | [
"Seems similar enough that it might be a duplication of this answered question.scifi.stackexchange.com/questions/286709/…",
"This makes me think of a story I read in which garlic has been restricted onboard a spaceship, not due to a shortage, but because the aliens who have infiltrated the ship are allergic to it... | 19 | Life & Arts | 0 |
429 | scifi | Short story about a man in a madhouse who asks the guard for a cigarette and tells him his story about having swapped bodies before | I am searching for a short story about a man locked in a madhouse who swaps his body with the guard/doctor while he tells him the story about his own body being swapped.
I remember the following:
* The madman asks the guard for a cigarette and starts telling him his own story.
* There was some relative of the mad... | https://scifi.stackexchange.com/questions/223920/short-story-about-a-man-in-a-madhouse-who-asks-the-guard-for-a-cigarette-and-tel | [
"story-identification",
"short-stories"
] | 35 | 2019-12-03T05:39:17 | [
"I, too, remember this story. I've been trying to recall the title for years now. I first read it sometime in the early 90s in a short story anthology I picked up while living in Brazil. I'm pretty sure the collection was published for ESL students, as I remember it was in the library of the language school \"Assoc... | 6 | Life & Arts | 0 |
430 | scifi | A story about a doctor who travels to a parallel universe to seek a cure for bubonic plague | Recent news has been reminding me of various things I've read about the black death, including a story I believe I only saw once, and never stumbled across again. I encountered it over 30 years ago, so I remember nothing of such details as character names. (Not even what city, in what country, it was set within.) I kno... | https://scifi.stackexchange.com/questions/230744/a-story-about-a-doctor-who-travels-to-a-parallel-universe-to-seek-a-cure-for-bub | [
"story-identification",
"short-stories",
"alternate-history"
] | 33 | 2020-05-02T21:28:52 | [
"Nourse did write at least one story about the plague but it has a very different plot.",
"0 I have read this story and remember it. I am 80% certain it was a short story written by Alan E Nourse, who wrote lots of medical sci fi stories. Hunted through my collection to see if I can locate it but annoyingly, I c... | 5 | Life & Arts | 0 |
431 | scifi | SciFi Short Story about an immortal man digging through an asteroid to meet a woman | Short story from the 80's or 90's, I saw someone asking about this on another forum but never got an answer. I've been curious ever since.
The story is set in a decadent future where everyone lives forever and mostly they go to parties. Guy meets a girl at a party, suggest he start at one side of an asteroid and digs ... | https://scifi.stackexchange.com/questions/120302/scifi-short-story-about-an-immortal-man-digging-through-an-asteroid-to-meet-a-wo | [
"story-identification",
"short-stories"
] | 30 | 2016-02-22T23:57:46 | [
"That's not a knife, that's a spoon!"
] | 1 | Life & Arts | 0 |
432 | scifi | A man sent to a parallel Earth to save someone important | This is not a novel, but "longish" short fiction, novelette or novella. I read it around 1984, in English, in an already used collection containing half a dozen or so stories.
A man, on our Earth, is contacted by a bizarre agency that offers him to get his mind transferred to a body in an alternate Earth, in order to ... | https://scifi.stackexchange.com/questions/211068/a-man-sent-to-a-parallel-earth-to-save-someone-important | [
"story-identification",
"parallel-universe",
"novella"
] | 29 | 2019-04-28T10:07:19 | [
"@MadPhysicist Very funny. I was referring to en.wikipedia.org/wiki/Graphic_violence IIRC the scenes with the cannibals did involve some violence and some blood, but well within the very moderate criteria of SF at that time. So as I understand this wiki page, they was no \"gore\".",
"@Alfred en.m.wikipedia.org/w... | 25 | Life & Arts | 0 |
433 | scifi | Short story about an elite that has mentally regressed due to assistive AI technologies | I came upon a comment describing a scifi short story where reliance on technology meant to improve appearance and demeanor has led to mental regression and AI control of the upper class that employs it. Unfortunately, I only have the following description to go on:
> I'm reminded of a Nebula(?) Award winning short sto... | https://scifi.stackexchange.com/questions/216852/short-story-about-an-elite-that-has-mentally-regressed-due-to-assistive-ai-techn | [
"story-identification",
"short-stories"
] | 29 | 2019-07-31T04:37:14 | [
"\"The Girl-Thing who went out for Sushi\"? Pat Cadigan, won the Hugo award for best novelette in 2013. Doesn't match all the details perfectly though.",
"You've rekindled a memory - I have definitely read this story! But I can't for the life of me remember the name nor author. I hope you find the answer. I'll ha... | 5 | Life & Arts | 0 |
434 | scifi | Old sci-fi short story about buying an android? | Long, long time ago I came upon a collection of old (pre 1980s?) short sci-fi stories. I'm not 100% sure, but something makes me think they were by Russian authors.
One of them was about a woman, who lives a lonely life in her flat. She decides to buy a male android. There's an android factory where you can choose you... | https://scifi.stackexchange.com/questions/63197/old-sci-fi-short-story-about-buying-an-android | [
"story-identification",
"short-stories",
"androids"
] | 28 | 2014-07-13T13:24:36 | [
"this may help you en.wikipedia.org/wiki/List_of_fictional_robots_and_androids",
"Not Asimov's Satisfaction Guaranteed?"
] | 2 | Life & Arts | 0 |
435 | scifi | Aliens secretly use video game to get humans to solve their problems | I recall a story probably 20-30 years ago (pretty sure it was a short story) in which a top gamer hears about a new computer game out that no one can beat. So he gets it and starts playing it. (Pretty sure it was before the age of playstation & x-box so it might be even older)
IIRC the game had little or no intro or r... | https://scifi.stackexchange.com/questions/253816/aliens-secretly-use-video-game-to-get-humans-to-solve-their-problems | [
"story-identification",
"short-stories",
"aliens",
"computers"
] | 28 | 2021-09-14T22:10:07 | [
"Vinge's The Peace War has an orbital mechanics game , but no aliens",
"Last Starfighter had a weaker variant of this.",
"While Pegman is a similar story (Aliens use humans to solve their problems by playing a video game) it is not the story I was thinking of. And a glance through Peace War it did not involve A... | 9 | Life & Arts | 0 |
436 | scifi | 70s book/short story, Man wakes up from suspend animation or cryo and world has collapsed | In the book, the protagonist wakes up from either suspended animation or cryo (Probably supposed to be a short test), After 10-20 years have passed.
He finds the facility abandoned (and looted?), gets to the surface and it looks like a war zone. Wreckage everywhere, smashed buildings, bullet holes everywhere. (I think... | https://scifi.stackexchange.com/questions/185987/70s-book-short-story-man-wakes-up-from-suspend-animation-or-cryo-and-world-has | [
"story-identification",
"short-stories",
"post-apocalyptic",
"suspended-animation"
] | 27 | 2018-04-19T23:18:42 | [
"I wonder if this is one of Octavia Butler’s novels? Or a confused misremembering, perhaps of the Clay’s Ark series?",
"@AcePL Your probably right, I maybe miss remembering tYotQS.",
"@OrganicMarble - I vote for your proposition. Except for suspended animation it all adds up. And description of the device to tr... | 6 | Life & Arts | 0 |
437 | scifi | Old SF novel about Earth as a prison planet; newly arrived convict has a secret agenda | I think I read this no later than the year 1986. English language, hardback, available in a public library in Indiana in the mid-1980s. I don't think it was by any of the Big Names of 20th Century science fiction, or else I would have run across it again by now. It was a stand-alone novel; no cliffhanger ending, and no... | https://scifi.stackexchange.com/questions/214680/old-sf-novel-about-earth-as-a-prison-planet-newly-arrived-convict-has-a-secret | [
"story-identification",
"novel"
] | 27 | 2019-06-17T19:10:13 | [
"Heh, thanks for the help. You solved mine but I didn't solve yours. I never heard of some of these others but thought the other forums might trigger ideas. .. Ah, yas... \"the boredom of a too-civilized society\". . . as if Heinlein hadn't harped on that enough. thanks for the story reminder.",
"@OccamShave \"... | 12 | Life & Arts | 0 |
438 | scifi | Story about a rainstorm that only the blind can see | I would have read this some time probably in the early 1990s. I don't remember how old it was at the time.
I only remember the beginning, and a snatch of details from it:
* Several blind characters
* One of the blind characters told his mother to take her umbrella with her, because it was raining. She looked but... | https://scifi.stackexchange.com/questions/144809/story-about-a-rainstorm-that-only-the-blind-can-see | [
"story-identification"
] | 27 | 2016-11-08T08:30:37 | [
"synesthesia is the name of the phenomenona where the senses get cross wired and the subject sees sounds and hears colors and so on. In case it helps someone. en.m.wikipedia.org/wiki/Synesthesia_in_fiction",
"I don't understand. What good were the umbrellas if the raindrops were making holes in them? Why did... | 16 | Life & Arts | 0 |
439 | scifi | Aliens try to liberate "enslaved" dogs from humans | I saw this story in an anthology in a used bookstore in 2009.
When the aliens came, we negotiated a peace treaty with them. Everything was going fine until they said "oh, and you'll have to stop keeping dogs as slaves, of course."
Humans said "what? No, they're not slaves, they're pets. They're not sapient!"
Aliens ... | https://scifi.stackexchange.com/questions/213338/aliens-try-to-liberate-enslaved-dogs-from-humans | [
"short-stories",
"aliens",
"story-identification"
] | 25 | 2019-05-26T20:15:07 | [
"Hi! Welcome to sci-fi. For some help improving your question, see this awesome guide."
] | 1 | Life & Arts | 0 |
440 | scifi | Spanish-language comic book story about time-traveling Jewish kids becoming the legendary Adam and Eve? | Around 1992 or 1993, I borrowed a comic-book-format magazine from someone. It was a pretty thick publication (well over 100 pages, I'm thinking; maybe over 200?) and was printed in **Spanish.** I _think_ I noticed this particular magazine had been published in Argentina, but I won't swear to that. The contents of this ... | https://scifi.stackexchange.com/questions/148842/spanish-language-comic-book-story-about-time-traveling-jewish-kids-becoming-the | [
"story-identification",
"comics",
"time-travel"
] | 25 | 2016-12-30T16:54:31 | [
"@RobertColumbia I don't think I've ever read anything by Borges, so I have no idea whether he ever did an \"Adam and Eve\" story or not. For all I know, it's possible that what I saw was a comic book adaptation based on the plot of a prose story written many years earlier by Borges (or by someone else).",
"I see... | 8 | Life & Arts | 0 |
441 | scifi | Car crash leaves man in a world devoid of animal and human life. Sees red flashes with demons and voices | It was a movie from the late '80's to the early '90's.
A man and his girlfriend/wife are in a car arguing, driving down a road on a stormy night. They wreck, and she is gone, and he has a bad headache. He suffers headaches throughout the movie I think.
During the day there is nobody on the planet (no animals either),... | https://scifi.stackexchange.com/questions/215178/car-crash-leaves-man-in-a-world-devoid-of-animal-and-human-life-sees-red-flashe | [
"story-identification",
"movie",
"horror"
] | 24 | 2019-06-27T15:37:29 | [
"A really long shot, but any chance that this was the man and this was the woman? I fed some of the keywords you mentioned to IMDb and it came up with something called Cumulus 9 from 1992, though it's doubtful this film was even officially released.",
"I recommend you to check this website, it might help you reme... | 2 | Life & Arts | 0 |
442 | scifi | Short story involving a lost-tech green glass highway in Australia | My mom's been wondering if I could find this story but I really can't without more specific details than she can give me. It's rather old, she guessed somewhere in the 1960s or 70s. The story wasn't centered about the science fiction aspects from what she remembers, it was more of a murder mystery or detective story th... | https://scifi.stackexchange.com/questions/104888/short-story-involving-a-lost-tech-green-glass-highway-in-australia | [
"story-identification",
"short-stories"
] | 24 | 2015-10-11T12:49:43 | [
"It's not the answer, but my first thought was Terry Dowling's shatterwrack (but that comes from the vehicles not the road)",
"Although it was published in 2005, Sean Williams's \"The Resurrected Man\" has some elements in common with this. It stars a private detective in a future Australia. There's a bit where a... | 5 | Life & Arts | 0 |
443 | scifi | Astronauts on Europa (moon), time-shift future, gravity, intelligent computer, Aries, 1960s? | I'm looking for the title and artists of a comic about some astronauts (around five I think) doing research/archaeology on (I think) Europa (Jupiter's moon). They're working when one or more of them sees the ghostly image of a girl/young woman shimmering at a distance. Later the woman appears again, seemingly more soli... | https://scifi.stackexchange.com/questions/102392/astronauts-on-europa-moon-time-shift-future-gravity-intelligent-computer-a | [
"story-identification",
"comics",
"time-travel",
"space",
"hard-sci-fi"
] | 24 | 2015-09-09T12:40:42 | [
"@Buzz You edited this question just to correct \"where ever\" to \"whereever\"? So now I have to correct \"whereever\" to \"wherever\".",
"I don't know the answer, but the genre makes it sound like it might originally have been published in one of EC Comics' sci-fi magazines; Weird Science, Weird Fantasy, Weird ... | 2 | Life & Arts | 0 |
444 | scifi | Short story where scientist flees to the ancient past, tries to stop scientific progress to keep man "pure"? | **Plot Summary/Details**
I can only recall the broad theme and a few details on this one. The protagonist, who was a scientist of some sort, has fled his own time to return to man's early period. I'm not sure of the exact time period, but I would guess it is very early on in the era of _Homo Sapiens_.
I cannot remem... | https://scifi.stackexchange.com/questions/167572/short-story-where-scientist-flees-to-the-ancient-past-tries-to-stop-scientific | [
"story-identification",
"short-stories"
] | 24 | 2017-08-19T17:49:57 | [] | 0 | Life & Arts | 0 |
445 | scifi | Article about science fiction languages | I'm looking for a journal item, probably written between 1992 and 1994, which discusses languages from Venus on the Half-Shell, Sagan's Contact, and several other novels, usually science fiction, containing "made up" languages. I got the books and cannot find the article; it is not in the book Aliens and Science Fictio... | https://scifi.stackexchange.com/questions/55517/article-about-science-fiction-languages | [
"story-identification",
"languages"
] | 24 | 2014-05-03T00:04:46 | [
"In case it helps, a wealth of resources, links etc at joerg-rhiemeier.de/Conlang",
"There have been many articles written in constructed languages in science fiction. You'll really have to give more than that.",
"Any idea in which journal you might have come across it?",
"You might be interested in the \"Lin... | 6 | Life & Arts | 0 |
446 | scifi | Looking for the source of this quote I copied in Dec 1987 | The copied quote is:
> 12-2-87
>
> "Forty thousand legions walked across the desert of the moon in search of the land of Narda. The fly space was crowded by their cars and travel logs. The sun rose in the East as the terminator marched over the dusty air-less surface pockmarked by the cosmic acne of space.
>
> They ... | https://scifi.stackexchange.com/questions/255498/looking-for-the-source-of-this-quote-i-copied-in-dec-1987 | [
"story-identification"
] | 22 | 2021-10-30T14:34:01 | [
"Jacob, good question, but it doesn't read like my writing style. Guess I'll never know.",
"If you don't recall its source, what makes you think it was a quote at all and not simply your own composition? Was manually copying long SF passages something you specifically remember doing?",
"You've got a date of \"1... | 8 | Life & Arts | 0 |
447 | scifi | Man accidentally hired into government position, uncovers an attempted alien invasion | This is a book science fiction story. A man was accidentally hired into a (secret?) government position due to having the same exact name as their intended hire. I think that his name was "Mr. Kennedy", but I'm not sure. I don't remember, is he required to take the job or not, but he takes it. He then becomes a part of... | https://scifi.stackexchange.com/questions/228567/man-accidentally-hired-into-government-position-uncovers-an-attempted-alien-inv | [
"story-identification",
"aliens",
"dystopia"
] | 22 | 2020-03-13T13:57:56 | [
"I'd be interested in reading this book one day. It sounds like a good book. :)",
"Also if you do post the answer, please post excerpts of the book which match these parts of the plot that I remember reading.",
"@Jenayah I originally read this book 10 years ago in a public library. I don't know the name of the ... | 4 | Life & Arts | 0 |
448 | scifi | Short story: Lost starship crew in suspended animation trying to return to Earth. Crew suicide a factor | Read a sci-fi anthology sometime in the 1980s, though the story feels like it's from the 50s or 60s. An all-male starship crew is trying to return to Earth after performing some mission, but they're lost and for [reasons] are reduced to wandering from system to system.
The crew is in suspended animation between system... | https://scifi.stackexchange.com/questions/139009/short-story-lost-starship-crew-in-suspended-animation-trying-to-return-to-earth | [
"story-identification",
"short-stories"
] | 22 | 2016-08-28T10:36:03 | [
"Haven't figured it out yet. The lighthouse bit sounds right. Getting closer...",
"Hey, I’m searching for this short story as well. Did you ever find out the title? I think the structure is a stone lighthouse (I could be wrong) and the captain reads the account of mankind’s extinction in a log book of sorts. I th... | 7 | Life & Arts | 0 |
449 | scifi | A ruined USA, where protagonists are captured by a biker bandits encamped in a zoo | It was written in English. I read it around 2013-2014 in British Columbia, Canada when I was in middle school.
It could have been a short series, or one book.
The protagonists are young adults, and so the book was probably for young adults.
The setting is a post-apocalyptic/heavily resource-drained world, with the ... | https://scifi.stackexchange.com/questions/166731/a-ruined-usa-where-protagonists-are-captured-by-a-biker-bandits-encamped-in-a-z | [
"story-identification",
"young-adult",
"post-apocalyptic"
] | 22 | 2017-08-08T01:29:33 | [
"Can you remember whether there were religious undertones? I read something similar in the '80s. The people still celebrated Christmas but it was illegal to believe in God or have a religion. Does that ring a bell? Not that I can remember the book!",
"This question would be improved by going through the checklist... | 2 | Life & Arts | 0 |
450 | scifi | WW2 airman is thawed out, and saves Earth from interplanetary invasion | I am trying to find the title and author of an extremely pulpy science fiction yarn. Unfortunately I do not know how the cover was - the version I had was secondhand, and in the vicissitudes of its life the cover was lost by the time the book came to me. It was definitely old - I suspect from either the 1950s, or possi... | https://scifi.stackexchange.com/questions/246437/ww2-airman-is-thawed-out-and-saves-earth-from-interplanetary-invasion | [
"story-identification",
"novel"
] | 21 | 2021-04-29T05:53:07 | [
"@user14111 Yes to both questions. I also have the impression it was British rather than American, but I am not 100% sure of that.",
"English language? Paberback?",
"This is of course not the yarn you're looking for, but such a rotating bowl of mercury was used by Number 774, the Martian protagonist of Raymond ... | 6 | Life & Arts | 0 |
451 | scifi | Short story about a giant ship that thoughtlessly destroys planets as it travels, is visited by a victim | I think I came across this ten or fifteen years ago, I cannot remember much clearly so some of these details may be mistaken. The story is told from the perspective of a crew member, on the bridge I think.
The ship is described as utterly enormous, sleek, and silver colored; I think it has been cruising at (near?) lig... | https://scifi.stackexchange.com/questions/240103/short-story-about-a-giant-ship-that-thoughtlessly-destroys-planets-as-it-travels | [
"story-identification",
"short-stories",
"aliens",
"generation-ship"
] | 21 | 2020-12-07T03:28:52 | [
"I'm thinkng of Stephen Baxter's Xeelee Sequence, particularly Flux (if the \"ship\" is allowed to be a neutron star).",
"@Tango: No, the description doesn't match a Berserker story. Berserker ships have an AI and are definitely not piloted by lifeforms. They may have prisoners, and in at least one case an obedie... | 5 | Life & Arts | 0 |
452 | scifi | What's this serialised comic strip about a girl who discovers everyone around her is a robot? | As a kid in the '80s, I found myself often in doctor's waiting rooms. I devoured most of the comic magazines there. In one of those, I read fragments of a story that I would like to find.
The story was set in (then) current time. The protagonist was a teen girl, who discovered that people around her had been replaced ... | https://scifi.stackexchange.com/questions/199749/whats-this-serialised-comic-strip-about-a-girl-who-discovers-everyone-around-he | [
"story-identification",
"comics",
"robots"
] | 21 | 2018-12-03T01:28:10 | [] | 0 | Life & Arts | 0 |
453 | scifi | Old movie involving unexplained handprint on mirror in spaceship | I would like the title of an old black-and-white movie. My best guess is that it would have been released in the 1950s or early 1960s, as I saw at least a small part of it when I was about ten years old (1964).
It was a live-action film in English, presumably American or British in origin, but it could have been dubb... | https://scifi.stackexchange.com/questions/188716/old-movie-involving-unexplained-handprint-on-mirror-in-spaceship | [
"story-identification",
"movie"
] | 21 | 2018-05-30T15:02:29 | [
"The only image of a handprint in a glass in a spaceship that comes to my mind belongs to Ark (2009). A canceled TV series (only one episode) from director Trey Strokes. I could be a coincidence or possibly inspired by your movie. imgur.com/a/PEVjPKk",
"Sounds like an awesome premise for a sci fi psychological/h... | 2 | Life & Arts | 0 |
454 | scifi | Continent sized, X-shaped alien | I have a vague recollection of this book, mostly the X-shaped alien. I can’t find anything through internet searches. I thought it may be some sort of “choose your adventure” book, but I haven’t seen it on any lists or pages discussing those sorts of books.
Alien description:
* Hugging a water world. Looks like reg... | https://scifi.stackexchange.com/questions/268271/continent-sized-x-shaped-alien | [
"story-identification",
"books"
] | 20 | 2022-10-03T11:36:53 | [
"Legacy by Greg Bear is about continental scale organisms",
"I read this as well! There was another scene in which one of the protagonists lay down on a stone altar/bed, and the alien began lulling him to sleep and moulding itself to his form. Also looking for it, but know that I read it sometime before the turn ... | 8 | Life & Arts | 0 |
455 | scifi | A story about a music teacher, cheated by a used-car salesman, and society begins to unravel | The story opens with the teacher (I can't remember his name, so call him 'Whosit') stranded because his 'new' car has died, phoning the salesman, hoping for redress, and being blown off.
Suddenly the world turns on the salesman: at first amusingly, but then it snowballs into horror — we see the salesman's wife walking... | https://scifi.stackexchange.com/questions/263954/a-story-about-a-music-teacher-cheated-by-a-used-car-salesman-and-society-begin | [
"story-identification"
] | 20 | 2022-06-03T12:56:22 | [
"Almost certainly a short story. Maybe a long short story--I always remember things as shorter than they were.",
"Is this a short story, or a novel?",
"Scope-wise, it sounds very Twilight Zone-y."
] | 3 | Life & Arts | 0 |
456 | scifi | Lost novella or short story: Either uplifted or evolved animals finally break through a barrier to discover that the humans have left Earth | The protagonist, possibly an uplifted or naturally evolved bear is in charge of a project to breach a barrier. This has kept all intelligent species from leaving the area. They eventually break through to discover a final message left by humans.
They have left the Earth to move out into space and were either responsib... | https://scifi.stackexchange.com/questions/237062/lost-novella-or-short-story-either-uplifted-or-evolved-animals-finally-break-th | [
"story-identification",
"short-stories"
] | 20 | 2020-09-16T10:31:39 | [
"Heinlein's novella Lost Legacy ends with an idea like this, but it's only the last 2-3 paragraphs, not the entire novella.",
"Wow, this question is from 2020? And ChatPig can't tell you?",
"L. Sprague de Camp wrote some stories about an uplifted bear, Johnny Black, but the ones I've skimmed all feature humans ... | 9 | Life & Arts | 0 |
457 | scifi | Looking for a children's or young adult novel about three kids travelling to a fantasy land | I've been trying to remember the title of a children's or young adult book I read as a child about thirty years ago. (So it may be from '70s or '80s). I don't remember many of the details.
There were three main protagonists; I want to say that all three were boys (maybe one was a girl), one of them may have been from... | https://scifi.stackexchange.com/questions/35701/looking-for-a-childrens-or-young-adult-novel-about-three-kids-travelling-to-a-f | [
"story-identification",
"young-adult",
"childrens-novel"
] | 20 | 2013-05-16T13:16:21 | [] | 0 | Life & Arts | 0 |
458 | unix | How to escape from a hardened chroot on Linux when only file capabilities are available to the attacker? | There is a chroot environment in `/var/myroot`, and an attacker has obtained arbitrary machine code execution in a process running as root (EUID 0) in the chroot. But the processes under control of the attacker don't have all capabilities enabled (just filesystem capabilities). The attacker wants to escape the chroot, ... | https://unix.stackexchange.com/questions/492473/how-to-escape-from-a-hardened-chroot-on-linux-when-only-file-capabilities-are-av | [
"linux",
"security",
"chroot",
"capabilities"
] | 6 | 2019-01-04T05:23:07 | [
"@A.B: I agree that using a well-maintained container setup tool (such as LXC or runc) gives better security than reinventing the wheel and doing it halfway. However, in this question I'd like to better understand what the attack vectors are (some of which may be mitigated by LXC and runc, some aren't). I've just u... | 4 | Technology | 0 |
459 | unix | Restoring in-memory/swapped page state on resume from hibernation | I'm a big fan of Linux's hibernation support, which works extremely well on all the (admittedly slightly older) hardware I've tried it on. I highly prefer it to full shutdown and power up.
There's one thing about hibernation that's bugged me for a while, though: a hibernated system is always sluggish and unresponsive ... | https://unix.stackexchange.com/questions/242264/restoring-in-memory-swapped-page-state-on-resume-from-hibernation | [
"linux",
"swap",
"io",
"hibernate",
"high-performance"
] | 5 | 2015-11-10T17:00:13 | [
"Note: implemented a script to read memory of specified PIDs back to memory explicitly. Maybe it can be a part of the solution."
] | 1 | Technology | 0 |
460 | stats | Is there a general expression for ancillary statistics in exponential families? | An i.i.d sample $X_1,\dots,X_n$ from a scale family with c.d.f. $F(\frac{x}{\sigma})$ has $S(X)$ as an ancillary statistic if $S(X)$ depends on the sample only through $\frac{X_1}{X_n},\cdots,\frac{X_{n-1}}{X_n}$.
1. Is this result also sufficient?
2. Is there a parallel result for a general exponential family whi... | https://stats.stackexchange.com/questions/193331/is-there-a-general-expression-for-ancillary-statistics-in-exponential-families | [
"mathematical-statistics",
"references",
"exponential-family",
"information-geometry",
"ancillary-statistics"
] | 25 | 2016-01-31T06:18:42 | [
"Not yet. Exponential families can have multiple parameters and the distributions can vary widely. It's really hard to come up with a general expression that is independent of all these parameters.",
"Ghosh, M., et al. “ANCILLARY STATISTICS: A REVIEW.” Statistica Sinica, vol. 20, no. 4, Institute of Statistical S... | 5 | Science | 0 |
461 | stats | Is the Wilcoxon two-sample test maximally powered to detect proportional odds alternatives? | We know from the literature that
* The Wilcoxon-Mann-Whitney two-sample rank sum test is optimal for detecting simple location shifts when comparing two continuous random variables that each have a logistic distribution
* The Wilcoxon test is a special case of the semiparametric proportional odds ordinal logistic ... | https://stats.stackexchange.com/questions/439672/is-the-wilcoxon-two-sample-test-maximally-powered-to-detect-proportional-odds-al | [
"statistical-power",
"wilcoxon-mann-whitney-test",
"ordered-logit",
"semiparametric"
] | 21 | 2019-12-06T12:55:57 | [] | 0 | Science | 0 |
462 | stats | Generalization of degrees of freedom for t distribution for coefficients after multiple imputation | Donald Rubin has shown that regression coefficient estimates have fatter tails after multiple imputation and has provided a formula for the degrees of freedom to use as a t-distribution approximation to the coefficient estimates resulting from Rubin's rule for combining multiple imputations. I would like a generalizati... | https://stats.stackexchange.com/questions/220005/generalization-of-degrees-of-freedom-for-t-distribution-for-coefficients-after-m | [
"bayesian",
"missing-data",
"multiple-imputation",
"degrees-of-freedom",
"t-distribution"
] | 9 | 2016-06-21T08:41:32 | [] | 0 | Science | 0 |
463 | stats | Distribution/expected length of the shortest path in infinite random geometric graphs | Consider an infinite random geometric graph $G(\rho,d)$ in which vertices are uniformly and independently scattered over the 2D plane with density $\rho$ and edges connect the vertices that are closer than $d$.
What is the distribution/expected value of the length of the shortest path from a vertex $v_0$ to another v... | https://stats.stackexchange.com/questions/48063/distribution-expected-length-of-the-shortest-path-in-infinite-random-geometric-g | [
"probability",
"stochastic-processes",
"density-function",
"asymptotics",
"graph-theory"
] | 9 | 2013-01-18T15:57:33 | [
"The probability of having a neighbor at distance $l$ grows linearly since the circumference of the circle is $2\\pi r$. $\\frac{1}{\\pi d^2}$ is the normalizing factor to make the probabilities sum to unity.",
"I asked the question about a year ago and I can't remember if I copied the formula from somewhere or n... | 3 | Science | 0 |
464 | stats | First two moments of the ratio of the geometric mean to the arithmetic mean of Gamma random variables | Let $X_1,\ldots, X_n$ be $n$ uncorrelated random variables from a Gamma distribution with **different parameters** : $X_i \sim Gamma(k_i, \theta_i)$. What is the distribution of $$ U=\log \left[ \dfrac{\bar{X}}{\tilde{X}}\right]$$ where $\bar{X}$ is the sample arithmetic mean and $\tilde{X}$ is the geometric mean.
ED... | https://stats.stackexchange.com/questions/336677/first-two-moments-of-the-ratio-of-the-geometric-mean-to-the-arithmetic-mean-of-g | [
"mean",
"gamma-distribution"
] | 8 | 2018-03-25T14:57:11 | [
"@Jason, if the $\\theta_i$'s are not identical then we can consider each r.v. a scaled $\\chi^2$, then $\\sum X_i$ would be a sum of scaled $\\chi^2$ r.v. which can be approximated by another scaled $\\chi^2$ which would be a Gamma r.v.",
"@ToneyShields Can you clarify that point a little? I'm familiar with the ... | 21 | Science | 0 |
465 | stats | Time evolution of a Bayesian posterior | I have a question regarding the time evolution of a quantity related to a Bayesian posterior.
Suppose we have binary parameter space $\\{ s_1, s_2 \\}$ with prior $(p, 1-p)$, The data generating processes are Brownian motions with parameter-determined drift:
$$ dX_t = \theta_i(t) dt + dB_t $$
for deterministic func... | https://stats.stackexchange.com/questions/254097/time-evolution-of-a-bayesian-posterior | [
"probability",
"bayesian",
"mathematical-statistics",
"stochastic-processes",
"posterior"
] | 8 | 2017-01-01T16:33:21 | [
"How are the parameters $s_1$ and $s_2$ involved in the data generating process?"
] | 1 | Science | 0 |
466 | stats | Can these asymptotic conditional expectations be bounded from above? | **Problem Setup**
Let $\\{X^d_1, X^d_2, \cdots, X^d_n\\}$ be a $d-$dimensional zero-mean, i.i.d. random variables. Let $S_n^d$ be $$ S^d_n = \frac{\sum_{i=1}^n X_i^d}{\sqrt{n}} $$
Let $Y^d$ be a zero-mean normal random variable with covariance $\Sigma^d = \mathbb{E}\big[X^d(X^d)^T\big]$
The paper by [Bentkus](http:/... | https://stats.stackexchange.com/questions/210943/can-these-asymptotic-conditional-expectations-be-bounded-from-above | [
"normal-distribution",
"conditional-probability",
"conditional-expectation",
"asymptotics"
] | 8 | 2016-05-04T15:41:00 | [
"The last step is correct but useless because $\\int\\big|p_S(x)-p_Y(x)\\big|dx$ is total variation distance and it takes supremum over class of all sets. However $c_d(\\mathcal{A})$ is bounded only when the $\\mathcal{A}$ is set of convex set or Euclidean balls.",
"Are $S_n$ and $Y$ in the $\\sup$ inequality the... | 3 | Science | 0 |
467 | stats | QR decomposition of normally distributed matrices | Assume $M$ is an $N \times k$ Gaussian matrix, i.e., its entries are i.i.d. standard normal random variables, with $N>>k$. Take $D=\text{diag}(\lambda_1, \dotsc ,\lambda_N)$ for some fixed real scalars. I am interested in finding the p.d.f. of the $N \times k$ "unitary" matrix $Q$ from the QR decomposition of $DM$ (and... | https://stats.stackexchange.com/questions/228224/qr-decomposition-of-normally-distributed-matrices | [
"normal-distribution",
"linear-algebra",
"matrix-decomposition",
"chi-distribution"
] | 8 | 2016-08-04T03:21:51 | [
"@whumber , could you please clarify the simplest case with $N=2$ and $k=1$?",
"In general they are arbitrary. At the moment I am focusing on the case where $\\lambda_1=1$ and $\\lambda_i=\\lambda^{i-1}$ for $i=2,3,\\dotsc ,N$, i.e., they are geometrically decaying with a fixed parameter $\\lambda \\in (0,1)$.",
... | 4 | Science | 0 |
468 | stats | Sum of absolute values of T random variables | Where X is a r.v. following a symmetric T distribution with 0 mean and tail parameter $\alpha$.
I am looking for the distribution of the n-summed variable $ \sum_{1 \leq i \leq n}|x_i|$.
$Y=|X|$ has for PDF $\frac{2 \left(\frac{\alpha }{\alpha +y^2}\right)^{\frac{\alpha +1}{2}}}{\sqrt{\alpha } B\left(\frac{\alpha }... | https://stats.stackexchange.com/questions/79001/sum-of-absolute-values-of-t-random-variables | [
"probability",
"distributions",
"t-distribution",
"convolution"
] | 8 | 2013-12-08T13:18:38 | [
"I think this is very relevant stats.stackexchange.com/questions/10856/… because the distribution of |X| is 2 times the distribution of X and over the positive reals instead of the whole real line.",
"When $\\alpha$ is a positive odd integer, the PDF is a linear combination of the inverse tangent of $x/\\sqrt\\al... | 2 | Science | 0 |
469 | security | What encryption type does Windows Hello use for fingerprint information on Windows 10 latest build? | I've contacted Microsoft support and they said they don't support encryption, which is why I'm posting here.
Basically, what I'm wondering is, if a modern laptop has TPM 2.0 enabled and hardware encryption enabled and then they want to use Windows Hello for their fingerprint, what encryption type is used for that biom... | https://security.stackexchange.com/questions/148465/what-encryption-type-does-windows-hello-use-for-fingerprint-information-on-windo | [
"encryption",
"windows",
"fingerprint"
] | 5 | 2017-01-15T13:16:52 | [] | 0 | Technology | 0 |
470 | medicalsciences | What happened to all the centers for hiatus hernia? | I have been doing much research for years on the esophageal hiatal hernia. I found exactly one paper on-line (from the US military, I believe, I cannot relocate it) that mentioned in passing that there were dedicated hiatal hernia treatment centers all across the country around the 1950s.
What happened to them?
If th... | https://medicalsciences.stackexchange.com/questions/9258/what-happened-to-all-the-centers-for-hiatus-hernia | [
"gastroenterology",
"abdominal",
"esophagus",
"hernia"
] | 5 | 2016-09-15T17:27:15 | [
"Can you name a single center that does not exist anymore?"
] | 1 | Science | 0 |
471 | scicomp | Padua-type pointset for functions singular on line $x=y$ | The Padua points $\mathrm{Pad}_{n} \subset [-1,1]^{2}$ are a unisolvent pointset with optimal growth of Lebesgue constant, described in detail [here](https://www.researchgate.net/profile/Stefano_De_Marchi/publication/220493368_Algorithm_886_Padua2D---Lagrange_Interpolation_at_Padua_Points_on_Bivariate_Domains/links/091... | https://scicomp.stackexchange.com/questions/29179/padua-type-pointset-for-functions-singular-on-line-x-y | [
"algorithms",
"interpolation",
"projection",
"chebyshev"
] | 5 | 2018-03-28T08:42:32 | [
"The series is required for the interpolation, so I was hoping that I could get both out of the same code.",
"You should add those details to your question. Although, I am bit confused now do you want a Chebyshev interpolation or a Chebyshev series?",
"Let me clarify: The goal is to construct a routine which co... | 8 | Science | 0 |
472 | mythology | What is the origin of the story that kefir grains were given to Orthodox Christians in the Northern Caucasus by the Prophet Mohammed? | Several websites (for example, [here](https://www.russianlife.com/stories/online-archive/magical-kefir/) and [here](http://www.thewalkingencyclopedia.com/kefir/)) report the story that kefir grains, which are used in the making of [the fermented milk drink kefir](https://en.wikipedia.org/wiki/Kefir), were given to Orth... | https://mythology.stackexchange.com/questions/4828/what-is-the-origin-of-the-story-that-kefir-grains-were-given-to-orthodox-christi | [
"folklore"
] | 6 | 2018-04-28T18:35:52 | [
"I think its obviously \"propaganda\" both Russians and Byzantines were in contact with tribes that made kefir since time immemorial. So it would be like giving them yeast."
] | 1 | Culture & Recreation | 0 |
473 | mythology | Primary sources for Persian land of Shadu-kam? | I'd like to find the primary sources (if any) for a Persian mythical land called Shadu-kam. It's supposed to be the realm of the Peris, a kind of fairyland, but I can't seem to find much about it.
I discovered the name in Umberto Eco's _The Book of Legendary Lands_ , where it's described very briefly:
> ...Persian ro... | https://mythology.stackexchange.com/questions/1474/primary-sources-for-persian-land-of-shadu-kam | [
"persian",
"shahnameh"
] | 9 | 2016-03-02T07:02:42 | [
"You're on the right track when you mention the similarities between Caherman and Nariman: remember, translation techniques have improved vastly since Keightley was alive. I could be wrong, but my initial impression is that the best way to answer this question would be to try to search for parallels between Shad-u-... | 2 | Culture & Recreation | 0 |
474 | quant | What is the probability of ruin of a Geometric Ornstein-Uhlenbeck process? | I would like to calculate the probability of ruin (or, default), i.e. $$\text{Pr}(\tau<T),$$ where $\tau$ is the default time and $X_t$ follows the Geometric Ornstein-Uhlenbeck (O-U) process
$$dX_t=\kappa (\theta - X_t) dt + \sigma X_t^{\delta}dW_t,$$ with $\delta=1$.
I can find closed-form solutions for the cases $\... | https://quant.stackexchange.com/questions/34759/what-is-the-probability-of-ruin-of-a-geometric-ornstein-uhlenbeck-process | [
"mean-reversion",
"default-probability"
] | 7 | 2017-06-18T14:43:29 | [
"I tried to answer the question, but I am having difficulty interpreting the $\\delta$ parameter. Intuitively, wouldn't $\\delta = 1$ correspond with GBM?",
"True, so let's consider the case where $\\kappa<0$ and $\\theta >0$. In this case, my intuition is that default is possible. Think of $\\kappa=-1$ for simpl... | 5 | Business | 0 |
475 | quant | Taking into account the correlation in Barrier options on a Basket | In a Barrier option (where the contract cancels when the underlying hits the barrier) I succesfully found the way to compute the probability of a single underlying touching the barrier (with constant volatility). The problem comes when I have an average basket of underlyings $B_t$ $$ B_t = \sum_{i=1}^n \omega_iS_t,\qqu... | https://quant.stackexchange.com/questions/2420/taking-into-account-the-correlation-in-barrier-options-on-a-basket | [
"correlation",
"basket"
] | 7 | 2011-11-23T08:38:53 | [
"I think that $\\langle dW_t^{i},dW_{t}^{j}\\rangle=\\rho_{ij}dt$",
"@FKaria: Thanks for your explanation. Now I understand the relevance of your question. One workaround is of course to only check the barrier at the discrete timesteps, but this is sometimes a crude approximation I guess.",
"@user561749 This is... | 5 | Business | 0 |
476 | space | Does Privateer's tracking software Crow's Nest actually offer users something better than the previous state of the art? | CNN's [Steve Wozniak's new venture takes aim at space junk](https://edition.cnn.com/2022/03/01/tech/space-junk-steve-wozniak-privateer-scn/index.html) discusses a project with [Wozniak](https://en.wikipedia.org/wiki/Steve_Wozniak), [Alex Fielding](https://en.wikipedia.org/wiki/Alex_Fielding) and [Moriba Jah](https://en... | https://space.stackexchange.com/questions/58535/does-privateers-tracking-software-crows-nest-actually-offer-users-something-be | [
"debris",
"tracking",
"collision-avoidance",
"business",
"artificial-intelligence"
] | 7 | 2022-03-05T21:22:00 | [
"@DavidHammen one can now download the \"puffery\" and give it a try, it's in public beta. See the links in the bounty message.",
"In this case, I suspect the PR-puffery to which @OrganicMarble alluded was the standard crud in seen in press releases and related items. Almost all startups funded by venture capital... | 12 | Technology | 0 |
477 | space | Crew Dragon: How thick is the skin? | Auto body panels are about 20-gauge, or just under 1 mm thick. This is fine for many reasons: thin panels are light for good fuel economy and crumple easily for shock absorption without unnecessary mass---especially since body panels aren't normally part of a car's load-bearing structural frame.
But what about a space... | https://space.stackexchange.com/questions/51782/crew-dragon-how-thick-is-the-skin | [
"spacex",
"falcon-9",
"dragon",
"structural-design"
] | 8 | 2021-04-29T21:41:01 | [
"Hmmm... how thick are panels on commercial jetliners? Quick search says 2 to 4 mm for pressurized craft.",
"+1 and relevant to my comment where I'd assumed 3 mm of aluminum without a source."
] | 2 | Technology | 0 |
478 | space | Dragon Pad Abort hot fire, how much cleanup work was needed? | The day before the Pad Abort test attempt (May 5, 2015) SpaceX test fired the SuperDraco engines in a hot fire. Similar to how they test the Falcon 9 a day or three before launch, the engines spin up and fire, the booster/capsule is mechanically held down for the test.
But normally, SpaceX burns LOX/RP1 whose exhaust ... | https://space.stackexchange.com/questions/9045/dragon-pad-abort-hot-fire-how-much-cleanup-work-was-needed | [
"spacex",
"testing",
"abort",
"dragon-v2"
] | 8 | 2015-05-06T05:57:32 | [
"The Nitrogen Tetroxide fuels are quite toxic because they react with h2o to form nitric acid. For that reason, you don't want to breath the stuff in, burning the lungs. But the same high reactivity also means that the stuff will break down quickly. In the case of the shuttle, the landing team had a giant fan to bl... | 3 | Technology | 0 |
479 | or | MIP formulation for graph planarity test | In [this question](https://cstheory.stackexchange.com/questions/48099/integer-linear-program-formulation-of-planarity), it was asked wether a MIP formulation exists to test for a graph's planarity. The inputs are the graph's nodes and edges, and the output would be a certificate which guarantees that the graph is, or i... | https://or.stackexchange.com/questions/10399/mip-formulation-for-graph-planarity-test | [
"mixed-integer-programming",
"modeling",
"graphs"
] | 8 | 2023-05-01T00:42:22 | [
"As far as I checked Euler's theorem, It is not correct for the space with dimension $\\mathbb{R}^2$. As the graph was planar. (I am not aware of if there exists a counterpart).",
"My best bet would be that you can check if the graph has $K_5$ or $K_{3,3}$ as a minor, which is equivalent to planarity by Wagner's ... | 2 | Science | 0 |
480 | quantumcomputing | Is HHL still BQP-complete when the matrix entries are only in {0,1}? | I'm studying BQP-completeness proofs of a number of interesting problems of Janzing and Wocjan, and Wocjan and Zhang. Janzing and Wocjan show that estimating entries of [matrix powers](https://www.researchgate.net/publication/220295493_A_Simple_PromiseBQP-complete_Matrix_Problem) $(A^m)_{ij}$ with $A_{ij}\in\\{-1,0,1\\... | https://quantumcomputing.stackexchange.com/questions/13404/is-hhl-still-bqp-complete-when-the-matrix-entries-are-only-in-0-1 | [
"complexity-theory",
"hhl-algorithm",
"bqp"
] | 14 | 2020-08-19T17:26:40 | [
"(Having said that, seeing how having entries of {0,1} for $A$ is still not the same as having {0,1} entries for $A^{-1}$ or a matrix $\\tilde A$ whose powers you would like to learn about, I still think that having non-negative entries for $A$ itself is a bit of a red herring... once you take the inverse of $A$, n... | 6 | Technology | 0 |
481 | quantumcomputing | Can you programatically check whether a given set of gates is universal? | I am wondering if there is an automated way to determine whether a given set of quantum operations is universal.
More precisely, given a set of 1 and 2 qubit gates, can we write a program to determine whether this constitutes a universal gate set? If so, how might we do this?
**EDIT:** To clarify I'm interested in bo... | https://quantumcomputing.stackexchange.com/questions/32408/can-you-programatically-check-whether-a-given-set-of-gates-is-universal | [
"quantum-gate",
"universal-gates",
"transpile"
] | 9 | 2023-05-02T13:13:45 | [
"I came across this paper, and I think this will be useful to you.",
"It might be an incomplete analogy but - we can't square the circle with a ruler and a compass; however, Archimedes taught us that we can get arbitrarily close, by inscribing and circumscribing polygons. With that in mind, can the ruler and com... | 9 | Technology | 0 |
482 | quantumcomputing | Better "In-Place" Amplification of QMA | $\def\braket#1#2{\langle#1|#2\rangle}\def\bra#1{\langle#1|}\def\ket#1{|#1\rangle}$ In [MW05](https://arxiv.org/abs/cs/0506068) the authors demonstrate so-called "in-place" amplitude amplification for QMA, exhibiting a method for Arthur to amplify his success probability without requiring any increase in the size of Mer... | https://quantumcomputing.stackexchange.com/questions/8586/better-in-place-amplification-of-qma | [
"quantum-algorithms",
"complexity-theory",
"qma"
] | 8 | 2019-10-27T15:47:51 | [] | 0 | Technology | 0 |
483 | quantumcomputing | Qubit fidelity of DWAVE device | Since DWAVE quantum device is constructed using superconducting flux qubits, each qubit cannot be produced identically so that the fidelity of the qubit must be different. DWAVE only provides the information of their devices in terms of number of qubits, couplers, etc without any calibration data of each qubit on their... | https://quantumcomputing.stackexchange.com/questions/23916/qubit-fidelity-of-dwave-device | [
"experimental-realization",
"fidelity",
"d-wave"
] | 8 | 2022-02-02T07:43:05 | [] | 0 | Technology | 0 |
484 | retrocomputing | How much did Atari pay for GEM? | Atari licensed Digital Research's GEM graphic user interface for the ST. As <https://www.filfre.net/2015/04/the-68000-wars-part-2-jack-is-back/> puts it:
> And of course in the wake of the Macintosh the ST simply had to ship with a mouse and an operating system to support it.
> It was this latter that presented by fa... | https://retrocomputing.stackexchange.com/questions/15377/how-much-did-atari-pay-for-gem | [
"history",
"atari",
"atari-st"
] | 10 | 2020-06-28T21:34:26 | [
"@tofro - details of other similar deals (eg Microsoft's licensing of SCP's 86-DOS) are known. It's plausible that details of this deal have come to light via a similar route.",
"Sadly, I suspect that the intersection of “people who would have even known at the time” (C-suite, accountant) and “people who care eno... | 6 | Technology | 0 |
485 | retrocomputing | What was IBM's internal Specification Language of the 1980s? | Within IBM's internal Development community, there was a move in the 1980s to bring our skills up to date. As part of this, we were introduced to a specification language, independent of the programming languages of the time (PL/S and Basic Assembler for example), in which a specification would be implemented. This spe... | https://retrocomputing.stackexchange.com/questions/25868/what-was-ibms-internal-specification-language-of-the-1980s | [
"history"
] | 10 | 2022-12-14T00:21:28 | [
"Thanks @davidbak I’m not thinking of VDM which, like Z, is more mathematically formal than the IBM language I am searching for.",
"See if this article rings a bell - dl.acm.org/doi/abs/10.1145/356596.356598 (PDF is freely available here)",
"I'm thinking it was the \"Vienna Definition Language\"? foldoc.org/Vie... | 3 | Technology | 0 |
486 | stackoverflow | Ограничения на поиск пользователей через users.search api vk | У api вконтакте есть ограничение - 3 запроса в секунду. Однако у `users.search` есть какое-то своё ограничение на количество вызовов.
> Помимо ограничений на частоту обращений, существуют и количественные ограничения на вызов однотипных методов. По понятным причинам, мы не предоставляем информацию о точных лимитах.
... | https://ru.stackoverflow.com/questions/451645/%d0%9e%d0%b3%d1%80%d0%b0%d0%bd%d0%b8%d1%87%d0%b5%d0%bd%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bf%d0%be%d0%b8%d1%81%d0%ba-%d0%bf%d0%be%d0%bb%d1%8c%d0%b7%d0%be%d0%b2%d0%b0%d1%82%d0%b5%d0%bb%d0%b5%d0%b9-%d1%87%d0%b5%d1%80%d0%b5%d0%b7-users-search-api-vk | [
"javascript",
"vkontakte-api"
] | 8 | 2015-09-17T05:51:12 | [
"Возможный дубликат вопроса: Ограничения VK-APi",
"Но нельзя не согласиться с тем, что эта мера с неизвестным лимитом сильно портит жизнь и тем, кто готов играть по правилам. Видимо, выбирая защиту от злоупотреблений, недовольством соблюдающих правила пользователей решили пренебречь.",
"Если допустимое кол-во з... | 5 | Technology | 0 |
487 | stackoverflow | Максимально возможное заполнение в клеточном автомате "Life" | Меня интересует алгоритм вычисления максимально возможного количества "живых" клеток на поле размером 100х100. Предполагается, что это поле - развернутый тор. Стартовое и конечное положения меня не интересуют. Но это должно быть возможное игровое состояние - т.е. состояние, соответствующее правилам (а не, например, про... | https://ru.stackoverflow.com/questions/502844/%d0%9c%d0%b0%d0%ba%d1%81%d0%b8%d0%bc%d0%b0%d0%bb%d1%8c%d0%bd%d0%be-%d0%b2%d0%be%d0%b7%d0%bc%d0%be%d0%b6%d0%bd%d0%be%d0%b5-%d0%b7%d0%b0%d0%bf%d0%be%d0%bb%d0%bd%d0%b5%d0%bd%d0%b8%d0%b5-%d0%b2-%d0%ba%d0%bb%d0%b5%d1%82%d0%be%d1%87%d0%bd%d0%be%d0%bc-%d0%b0%d0%b2%d1%82%d0%be%d0%b... | [
"алгоритм"
] | 8 | 2016-03-14T07:25:23 | [
"Комментарии не предназначены для расширенной дискуссии; разговор перемещен в чат."
] | 1 | Technology | 0 |
488 | chemistry | Dry water using graphite | [Dry water](https://en.wikipedia.org/wiki/Dry_water) or "powdered water" is essentially a bunch of extremely small water droplets surrounded by $\ce{SiO2}$.
Some time ago, I was messing around and mixed some powdered graphite with water. (The graphite was obtained from a pencil, so it was not pure. Also I mixed the tw... | https://chemistry.stackexchange.com/questions/61838/dry-water-using-graphite | [
"water",
"mixtures"
] | 7 | 2016-10-30T06:48:15 | [
"Graphite for pencils is mixed with clay, which is largely composed of silicates. I don't know whether pure graphite powder would display the same behavior you describe.",
"I may end up doing something similar to this for a school project. If I decide to mix the graphite with water instead of ink, I will measure ... | 4 | Science | 0 |
489 | chemistry | Mathematical models of oscillatory chemical reactions | I am a mathematician working on real-life models in ordinary differential equations. I want to know if there are any models of oscillatory chemical reactions that consist of three ordinary differential equations where one variable is much slower than the other two. In particular I am interested in bursting behavior, wh... | https://chemistry.stackexchange.com/questions/166898/mathematical-models-of-oscillatory-chemical-reactions | [
"physical-chemistry",
"kinetics",
"theoretical-chemistry"
] | 7 | 2022-08-05T08:27:40 | [
"related? wrap.warwick.ac.uk/60495/1/WRAP_computation-02-00047.pdf",
"Related: mattermodeling.stackexchange.com/q/8812/5",
"Somewhat related"
] | 3 | Science | 0 |
490 | chemistry | Interaction of trifluoroacetates with acetylcholinesterase | There exists a substance called TMTFA, or 3-(_N,N,N_ -Trimethylammonio)-2,2,2-trifluoroacetophenone. It is known for being able to inhibit acetylcholinesterase at femtomolar concentrations. The TMTFA-AChE adduct resembles the tetrahedral transition state through which the hydrolysis of acetylcholine by the enzyme norma... | https://chemistry.stackexchange.com/questions/135747/interaction-of-trifluoroacetates-with-acetylcholinesterase | [
"organic-chemistry",
"biochemistry",
"proteins",
"esters",
"enzymes"
] | 5 | 2020-06-24T21:41:08 | [
"According to Ref.2, TMTFA binds titly to AcE from a Pacific electric ray, Torpedo californica. It might not do the same to Human AcE. I believe your intention is for inhibitors of Human AcE."
] | 1 | Science | 0 |
491 | chemistry | Reaction of Rubidium with vacuum system viewport | I have a vacuum system ($<1\times10^{-7}$ mbar) filled with Rubidium ($^{87}$Rb) vapour, at room temperature.
We also have a viewport near the Rubidium source, made of a stainless steel flange and a glass substrate, connected with a [Kovar](https://en.wikipedia.org/wiki/Kovar) alloy.
We are seeing potential degradat... | https://chemistry.stackexchange.com/questions/81551/reaction-of-rubidium-with-vacuum-system-viewport | [
"everyday-chemistry",
"home-experiment"
] | 5 | 2017-08-21T04:23:40 | [
"btw, thanks to ability of rubidium to form suboxides even tiniest amount of oxygen may bind a lot of rubidium.",
"Please, check the mark of the glass and if it is suited for work with rubidium in this particular settings. In general, glasses are oxides that can potentially react with alkali metals in right circu... | 2 | Science | 0 |
492 | hsm | Whence “homomorphism”, “homomorphic”? | The [kernel](https://hsm.stackexchange.com/questions/2149/what-came-first-the-kernel-from-vector-spaces-or-from-group-theory) question leads to another : Today, **_homomorphism_** (resp. _isomorphism_) means what Jordan ([1870](https://archive.org/stream/traitdessubsti00jorduoft#page/56)) had called _isomorphism_ (resp... | https://hsm.stackexchange.com/questions/6460/whence-homomorphism-homomorphic | [
"terminology",
"abstract-algebra",
"group-theory"
] | 9 | 2017-08-26T17:04:12 | [
"Now cross-posted: mathoverflow.",
"Homomorphism is etymologically correct in the sense that the structures of two groups exhibit a degree of similarity when one can map into the other (trivial cases apart). Isomorphism is then more accurately used to mean \"congruent\" structure. (\"Isos\" is more commonly used ... | 3 | Science | 0 |
493 | hsm | Who was the first to use the "does not exist" sign ∄? | Who was the first to use the "does not exist" sign ∄? I'm aware that Giuseppe Peano originated serifed ∃ and, moreover that Whitehead and Russell repurposed Peano's serifed ∃; I'm also aware that Gerhard Gentzen introduced the ∃ sans serif (and used it like Russell and Whitehead rather than like Peano). Yet, I cannot f... | https://hsm.stackexchange.com/questions/7181/who-was-the-first-to-use-the-does-not-exist-sign-%e2%88%84 | [
"terminology",
"notation",
"mathematical-logic"
] | 9 | 2018-03-26T14:01:36 | [] | 0 | Science | 0 |
494 | hsm | Who first defined polynomials as sequences? | > **Question 1.** When did the modern definition of a **polynomial** (as a sequence of coefficients, with multiplication defined by $\left(ab\right)_n = \sum\limits_{k=0}^n a_k b_{n-k}$) emerge?
Let me clarify: People have been working with some notion of polynomials for centuries, but mostly without a rigorous concep... | https://hsm.stackexchange.com/questions/9710/who-first-defined-polynomials-as-sequences | [
"mathematics",
"abstract-algebra"
] | 8 | 2019-06-07T14:43:53 | [
"Not in the modern sense, but that can be said about most of algebra until the late 18th century. Hudde further treated polynomials purely algebraically in the 17th. Dieudonne, before reinterpreting Euler's manipulations in terms of formal power series, states the following:\"These series appear in print in Hilbert... | 3 | Science | 0 |
495 | proofassistants | Unintentionally proven false theorem with type-in-type outside logic and foundations? | We are all familiar with Russell's paradox, and [it is known](https://proofassistants.stackexchange.com/a/1220) that Per Martin-Löf proved that type-in-type is normalizing and consistent (which is false), by accidentally using an assumption in his meta-theory that is essentially type-in-type. But all these arise in the... | https://proofassistants.stackexchange.com/questions/1238/unintentionally-proven-false-theorem-with-type-in-type-outside-logic-and-foundat | [
"foundations",
"history",
"predicativity",
"universe",
"consistency"
] | 13 | 2022-04-04T07:40:29 | [
"And negation is not even needed, nor is any notion at all about 'categories'. To see why, if type∈type, then let S be the 'type' of all types x such that ∀t∈{ 0 : x∈x } ( ⊥ ), and it is trivial to obtain ⊥ by constructive proof: Given any t∈{ 0 : S∈S }, we have S∈S and so ∀t∈{ 0 : S∈S } ( ⊥ ), hence ⊥. Therefore S... | 15 | Science | 0 |
496 | proofassistants | Rules for mutual inductive/coinductive types | Some proof assistants, like Agda and maybe Coq, allow families of mutually defined types, or nested definitions of types, in which some are inductive and others are coinductive. I have no idea what the type-theoretic introduction/elimination rules should be for such a family, and as shown in [this question](https://pro... | https://proofassistants.stackexchange.com/questions/980/rules-for-mutual-inductive-coinductive-types | [
"type-theory",
"coinductive-type",
"inductive-type"
] | 12 | 2022-03-06T12:57:18 | [
"I'm aware of Hening Basold's thesis. And Danielsson and Altenkirch's Mixing Induction and Coinduction has a long list of related work, some of which may have rules (e.g. the work on sized types).",
"I mean the 'partiality monad', which you can model as a HIT/QIT via the free ω-complete partial order on a type. A... | 4 | Science | 0 |
497 | biology | What's the difference between proliferation and diffusion when talking about changes in tumor density? | Cell proliferation and cell diffusion seem to be important quantities to estimate when trying to understand or measure tumor growth, but I don't really understand a) the difference between them or b) their relationship to tumor growth.
Cell proliferation refers to cellular subdivision. This doesn't necessarily mean t... | https://biology.stackexchange.com/questions/57119/whats-the-difference-between-proliferation-and-diffusion-when-talking-about-cha | [
"cell-biology",
"growth",
"differentiation",
"cancer"
] | 5 | 2017-03-08T10:29:49 | [
"A tumor by definition is an abnormal proliferation of cells but I don't think diffusion has anything to do with cells actually diffusing. Rather, the carrying capacity of a tumor depends on such parameters as nutrients or oxygen, which must diffuse further inwards until they cannot reach cells. Hence, the core of ... | 2 | Science | 0 |
498 | stackoverflow | ある一定のダウンタイムがある並列システムを、特定の確率以上で常に必要並列数を上回らせるために必要な並列数は? | 例えば web サービスは一般的にロードバランサーと並列数`N`で表されるワーカープロセスによって構築される場合が多いです。
今、あるワーカーが故障した時、そのワーカーが復帰するために必要な時間を`t`とします。ワーカーは、単位時間あたり`λ`の確率で故障し、その故障確率はそれまでの稼動時間に依らない、とします。
今、このサービスが問題なく稼動してワークロードをさばくためには、最低`m`個のワーカーがダウンしていない状態で稼動している必要があるとします。
このとき、確率論的に、ある一定の期間 `T` が与えられたとき、その期間の間のすべてのタイミングにおいて、上記の `m` 個のワーカーが稼動している確率 `p` が定義でき... | https://ja.stackoverflow.com/questions/85441/%e3%81%82%e3%82%8b%e4%b8%80%e5%ae%9a%e3%81%ae%e3%83%80%e3%82%a6%e3%83%b3%e3%82%bf%e3%82%a4%e3%83%a0%e3%81%8c%e3%81%82%e3%82%8b%e4%b8%a6%e5%88%97%e3%82%b7%e3%82%b9%e3%83%86%e3%83%a0%e3%82%92-%e7%89%b9%e5%ae%9a%e3%81%ae%e7%a2%ba%e7%8e%87%e4%bb%a5%e4%b8%8a%e3%81%a7%e5%b8%b8%e3%... | [
"数学"
] | 5 | 2022-01-01T23:26:31 | [
"> \"N, m, t, λ, T についての関数になっていると思うのですが\" 関数形を解析的に書けないように思います。 パラメータの値を具体的に与えたうえでシミュレーションして確率を求める方針をとることはできます。",
"課題か何かでしょうか。実務的にはほとんど意味がない計算にしかならないと思います(構成要素の網羅度が足りなさすぎる、ある程度網羅したら複雑すぎて計算は困難)"
] | 2 | Technology | 0 |
499 | retrocomputing | Plessey computer at Stanford? | While updating the wiki article on the 4004, I came across an interesting claim by Ted Hoff, who stated the idea of using a general-purpose CPU in a calculator came to him due to a minicomputer that had been donated to Stanford by the UK company Plessey.
I'm at a loss as to what this might be... I know Plessey had a r... | https://retrocomputing.stackexchange.com/questions/24545/plessey-computer-at-stanford | [
"minicomputers"
] | 9 | 2022-05-23T09:04:36 | [
"On the face of it, the dates don't work, but 1. the information in Wikipeda is not sourced 2. a prototype might have been given to a university before it was ready for sale - perhaps hardware would have been available before suitable software was written.",
"@mikado - had not heard of this - a little late for th... | 7 | Technology | 0 |
500 | retrocomputing | Looking for late 90s shareware open world racing game | I'm trying to track down a shareware racing game released somewhere between 1999 and 2004 - or at least, my parents found it bundled in a computer magazine during that time.
Here's what I remember about it:
* It was a Win9x game, 3D Flat shaded with hard edges and basically no textures, no actual transparency and r... | https://retrocomputing.stackexchange.com/questions/21755/looking-for-late-90s-shareware-open-world-racing-game | [
"identify-this-game"
] | 9 | 2021-09-09T01:58:28 | [
"Are you really sure that it is a Win9x game? Low Poly graphics without texturing could also mean, that it was a DOS game.",
"@thkala you were absolutely alone against time, and the car in the demo was just one extremely low poly sedan. The physics and handling weren’t too arcades, but very far from current day r... | 9 | Technology | 0 |
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