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Questions tagged [algorithm]

The tag has no usage guidance.

0
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0answers
14 views

Android / Java: Time efficient large scale Image processing to create median image [on hold]

I am trying to create an android app [using android studio]. the app captures 200 - 500 pictures in a set period of time, and then does some processing on all the images together. each picture's size ...
0
votes
0answers
4 views

the running time in Python and MATLAB about the simultaneous minimum and maximum algorithm [on hold]

The simultaneous minimum and maximum algorithm uses 3*n/2 comparisons, while the general one uses 2*n comparisons. But via Python or MATLAB, the former one's running time is higher than the general ...
1
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0answers
37 views

What determines what algorithms are available to OpenSSH?

Is the version of OpenSSH or the version of OpenSSL (or a combination of the two) that is installed on a given system what determines which Ciphers, KexAlgorithms, and MACs are available to be ...
1
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0answers
21 views

How to analyze file and know if messy or encrypted or else? [closed]

This is a abstract question for me, hope someone can direct me to one lane. I want to analyze content of file and want to know info like below: Is data of file suitable to do dedup? or it too messy ...
0
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1answer
280 views

Use ffmpeg for thumbnail selections

This is a follow-up question from HERE. I want to sample k frames out of the n number of frames in a given video using FFMpeg and its thumbnail filter. There is a post here providing some insights how ...
50
votes
1answer
5k views

What exactly is Excel's Auto Fill algorithm?

What is the algorithm used by Auto Fill in Excel? For example, when I enter the numbers 3,4,5,7,8 into a column and then use Auto Fill, I get the following result: 3 4 5 7 8 9.3 10.6 11.9 13....
-2
votes
1answer
53 views

Will this program terminate for every Integer? [closed]

In a Part Test for GATE Preparation there was a question : f(n): if n is even: f(n) = n/2 else f(n) = f(f(n-1)) I answered "It will terminate for all integers", because even for negative ...
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0answers
87 views

Override El Capitan Hash Algorithm to read High Sierra DMG image?

My Mac OS was corrupted, so in recovery mode I made a backup of my data files while @High Sierra (10.13.3). Unbeknownst to me, this created a DMG file that can only be opened in High Sierra. I ...
-3
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1answer
224 views

Designing a custom small DDoS detection and defense sytem [closed]

Am very new to the topic so I would like some guidance where to get started. What I want is, some tools to programmatically observe network traffic and preform some actions on the traffic. I don't ...
0
votes
1answer
782 views

Finding permutations of a number using bash script

Is it possible to write a bash script which takes a 4 digit number as an command line argument and produces all permutations of that number with using only pure bash?
1
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0answers
98 views

Implementation of qsort [closed]

I have been looking for implementation for qsort but using google I find implementation for something like this void qsort(int[] arr, int left, int right); What I want is implementation for ...
1
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0answers
36 views

Creating an specific type of meta-algorithm

I need to create a program able to create an algorithm to Matlab. For instance, in this program, I want to give it an integer n>0 and make it create a Matlab algorithm with the following code: u1 = ...
4
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3answers
804 views

How to achieve high-quality downscaling of diagrams (like in Firefox)?

I often need to downscale raster images consisting of thick straight lines and other thick curves, like this one: . Using GIMP 2.8.16 and its various interpolation options to resize the image to ...
1
vote
1answer
349 views

How can I find vendor name from MAC address of my NIC

So far I learned having my first 3 bytes of my MAC address(HEX format: 00:00:00:00:00:00) I can find my NIC's vendor name(which is a string). Can you elaborate this algorithm? No websites/tools links ...
-1
votes
2answers
122 views

How to make an arbitrary Microsoft FILETIME?

I would like to make an arbitrary Microsoft FILETIME. The algorithm is more important than the Microsoft programming language. For example if today is June 2 2016, I would like to calculate the ...
0
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0answers
36 views

Does such a cache (unreduce) actually exist?

I'm reading about cache replacement algorithms and one states (source, page 37) Def. A reduced schedule is a schedule that only inserts an item into the cache in a step in which that item is ...
1
vote
1answer
2k views

Allow browser to use more cores

I wrote an algorithm with JavaScript. When I execute it in Google Chrome, it takes about 30min, which is quite long. When I open the task manager during the computation, I can see that Chrome takes ...
0
votes
1answer
48 views

Is there a piece of software that will help me convert “Hex” code based on already known input and output? [closed]

The title is a little confusing, but the jist of it is this: I have a list of "HexCode" (I use that term loosely as they are not actually hex codes) from both before conversion and after conversion. ...
-1
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2answers
249 views

How to write a VBA code me which displays 10 random numbers between 1 to 50 without a repeat of the numbers

How do I write a VBA code me which displays 10 random numbers between 1 to 50 without a repeat of the numbers?
1
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1answer
1k views

How to simplify Excel/Google Sheets formula with redundant method calls?

I have an Excel (Well, technically Google Sheets) workbook containing product inventory warehouse storage information. I figured out how to construct queries so it grabs the needed information from ...
0
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0answers
401 views

Combining all combinations of data from 8, 9 and 10 columns in excel

I'm attempting to figure out how to run all possible combinations for data in 8, 9 and 10 columns (each on different pages) and would love to have a macro for each. Below is a macro for three ...
0
votes
1answer
20 views

Running time of locating a file in a directory

When you search for a file in a directory with a large number of files (n), what is the worst case running time of locating this file? I mean does the OS (linux) sequentially check all filenames in ...
1
vote
1answer
2k views

What is the hash algorithm for owncloud passwords

I need to know the algorithm used to generate the password hashs that look like this: $2a$08$ztQUBr1vx97Rc9MiJVr05.LZWg92jGYkRFEJViHhfZjaWpB0xfgGu It looks like bcrypt to me but when I hashed my ...
1
vote
1answer
115 views

Wireless Client Algorithm Used to Choose SSID/AP

Does anybody happen to know if it is possible to find (or determine) the actual algorithm that wireless clients use to choose which the BSSID to connect to when there are multiple SSIDs available at ...
0
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0answers
40 views

What is the data structure used by Recycle bin & hows it implemented [duplicate]

In a Windows file system, we cannot created a folder or file with the same name. For example, New Folder. If there is a existing folder already named as "New Folder" and if we create another folder ...
2
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0answers
82 views

Back of the envelope calculation for speed of matrix multiplications [closed]

I'm trying to develop an intuition for how feasible/scalable machine learning algorithms are. The dominant cost is always matrix multiplications, but there seem to be no readily Google-able resource ...
0
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1answer
459 views

Algorithm/Code for detecting colours in a picture [closed]

Is it possible to have code that can automatically detect the colours in a picture? If so what is this technology? Thanks,
1
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0answers
276 views

Understanding how Native Instruments Traktor analyzes and beat-grids songs

Quick Summary: How does NI Traktor determine: BPM (beats per minute) beat-grid key of song auto-gain Detailed Description: I am very interested in understanding exactly how Traktor analyzes a song; ...
2
votes
2answers
91 views

When we save a file in windows - is actual location of file on hard disk random or deterministic?

I want to know when we try to save a file to harddisk how the os saves the file to hard disk. Will two computers with same configuration and ALSO SAME INTERNAL STATE save the file on the same location ...
1
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0answers
147 views

How does a Benes network work?

How does a Benes network work? If I have a Benes network with 8 nodes on each side, like this one here: . . . how do I know whether or not I take the upper or lower port of a switch in each stage? ...
1
vote
0answers
217 views

How to unpack a compressed executable without knowing the compression algorithm

I'm not sure if this question was asked. I searched for it and could not find it. How can I unpack a compressed executable without knowing what compression algorithm was used to compress it? For ...
3
votes
1answer
705 views

A software to draw an algorithm [closed]

I'm currently working on a complex algorithm, and I want to draw it into a reference document. Basically, I have formulas, formulas are linked to their operands, operands are formulas themselves ...
0
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1answer
2k views

How to transfer data between two networks efficiently

I would like to transfer files between two places over the internet. Right now I have a VPN and I am able to browse, download and transfer files. So my question is not really how to transfer the files;...
6
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3answers
21k views

Scheduling algorithm used in Windows 7

What is the scheduling algorithm used in Windows 7?
3
votes
1answer
618 views

What algorithms are used in signature and heuristic virus detection? [closed]

I'm trying to write a paper on virus detection techniques. I've downloaded many journals, papers and used many websites. I have found overview definition for both of these terms but I would like to go ...
0
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4answers
2k views

Is there a hashing algorithm that allows me to specify output character length?

My security officer is looking for a hashing algorithm that will take a string of up to 20 characters, and then output a unique, 12-character alphanumeric hash. The 20-character string is generally ...
2
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1answer
890 views

Deleting music file duplicates but retaining iTunes metadata

Back when I first imported the majority of my iTunes library I had the copy files to iTunes Media folder when adding to library option checked, so basically my whole music library was duplicated on ...
4
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3answers
5k views

What's the fastest way to combine two or more files in Linux?

I want to combine two or more files in Linux, so I am using the following command: cat small_file LARGE_File LARGER_FILE > SUM_OF_FILES However this runs very slow. Does anyone know a Linux tool ...
4
votes
1answer
697 views

How synchronize two disks (or folders) using symbolic (or hard) links (like rsync)?

I'm searching a tool or a shell script or another program to synchronize two or more folders or disks. But it differs of rsync tool, because, I don't want to duplicate the missing file, but do a ...
2
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4answers
706 views

Encryption algorithm of gnome-keyring

What encryption algorithm does gnome-keyring use? I've tried looking for it on their site but it seems quite hidden.
1
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2answers
116 views

Algorithm Of Getting Information From Ip Adress [closed]

i want to know how some sites and some softwares give information from a given ip address?? i mean does it have a specific algorithm?
0
votes
1answer
57 views

A tool (library, source-code, algo) to select area in an image based on perceived focus plane

Say we have an image in which a human eye can distinctly see several "planes" of focus - a blurry background ("telelens"), the sharp(er) subject (a human, or an object), and again a blurry foreground (...
4
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2answers
2k views

How does SSD garbage collection work?

Correct me if I'm wrong but doesn't the block bitmap (which keeps track of free blocks on a disk drive) vary for different file systems (both location and structure wise)? So how can OCZ have a ...
5
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2answers
3k views

unix sort algorithm implementation

What sorting algorithm(s) is/are used in the unix sort command? Insertion/quicksort/etc.?
3
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3answers
425 views

When erasing freespace, why do utilities write random strings of data?

I've been reading about various utilities that erase the free space on your hard drive, and they all talk about doing multiple passes of writing random strings of 1's and 0's using various algorithms.....
13
votes
3answers
2k views

How do defragmenting programs work?

a) What algorithm would a typical defragmenting program use to get rid of the fragmentation? b) In Defraggler, I have a quick defrag option and a defrag option. Assuming defrag would do a normal ...
4
votes
3answers
6k views

Decrypt files encrypted with TrueCrypt

I have a usb pen memory crypted with TrueCrypt. Is there a way to decrypt ( without TrueCrypt ) files encrypted with TrueCrypt in linux ?
46
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7answers
120k views

What is the maximum compression ratio of gzip?

What is the largest size a gzip (say 10kb for the sake of an example) can be decompressed to?
37
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4answers
26k views

How are PID's generated?

On *nix, PIDs are unique identifiers for running processes. How are PID's generated? Is it just an integer which gets incremented or a more complex structure such as a list? How do they get recycled? ...
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4answers
3k views

week numbers in month. How to work it out?

ok, I am being stupid! I am doing a project plan and for each month I have the weeks 1-4. My question is, how to know which week number a particular date belongs to? I've played with outlook but it ...