Batch Size vs Mini Batch Size

Published on 2023-06-03 in Speech Recognition

Batch Size: There is no such a thing as batch size, there’s only mini batch size which is number of the samples you train your model on before updating the weight and biases but sometimes programmers just drop the mini in the term, and use batch sizes instead so basically batch size is exactly the same as the minibatch size. If we want to be absolutely correct though then the batch size is the number of samples we have in our data set and it’s not a number that you can specify in your program
MSE: Mean square root error will work best if you want to calculate the error for predicting a function regression, like predicting stock price, or a product lifetime failure function. In fact, there is no mean in MSE algorithm And the error is calculated between the neural network output and the prediction label. and then summation over all different samples.
Cross Entropy: Cross Entropy will work best if you want to do a classification like binary classification or even a multi-class classification. It helps by penalizing wrong class detection. The calculation of the cross-entropy function is fairly easy it is -log(p_target_class). So basically it only depends on the class that the input data is belonged to. In this case other classes error don’t have any impact on the network loss.
ArgMax: ArgMax is a function that is used at the final output layer of the neural network. It simply changes the class with the maximum number to one and all other cases to zero

slavv – 37 reasons why your neural network-is-not-working

Golden SSH Commands

Published on 2023-05-19 in Linux

Are you tired of entering your password for sshing into a remote server?
Are you tired of verifying host fingerprint changes every time?

Use this golden ssh command and save your valuable time

ssh -o "StrictHostKeyChecking no" -i ~/Documents/identify root@ip
echo "y\n" | HOSTNAME=`hostname` ssh-keygen -t rsa -C "$HOSTNAME" -f "$HOME/.ssh/id_rsa" -P ""
# copy key to remote
ssh-copy-id userid@hostname
sshpass -p pass ssh root@ip

CronTab @Reboot

Published on 2023-05-19 in Linux

You can use the @reboot keyword in crontab to start a shell script at system startup but here is why this isn’t a very good solution to do that.

The problem is that if you don’t shut down the system cleanly on the next startup this message will pop up and cron will simply skip over running your command.

"Skipping @reboot jobs -- not system startup"

The solution is easy, just use a systemd service.

/etc/systemd/system/service_name.service
------------------------------------------
[Unit]
Description=some description
After=network.target
StartLimitIntervalSec=0

[Service]
Type=simple
User=root
ExecStart=/home/user/script.sh

[Install]
WantedBy=multi-user.target

UnixDaemon – How Does Cron Reboot Work

Useful Firefox/Windows Hacks

Published on 2023-02-24 in Windows

Disable Firefox Update Prompt

run in cmd

reg ADD HKLM\SOFTWARE\Policies\Mozilla\Firefox /v DisableAppUpdate /t REG_DWORD /d 1 /f

or run ff_update_dis.reg

Disable Windows Keys

reg ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer /v NoWinKeys /t REG_DWORD /d 1 /f

or run win_key_dis.reg

Disable Shutdown Prompt Ending Application

reg ADD HKCU\Control Panel\Desktop /v AutoEndTasks /t REG_SZ /s "1" /f

or run win_end_task.reg

Disable Share Screen Prompt/Overlay

privacy.webrtc.hideGlobalIndicator

media.navigator.permission.disabled

Auto YouTube Play

media.block-autoplay-until-in-foreground

AddOn Restriction URL

extensions.webextensions.restrictedDomains -> set to null

privacy.resistFingerprinting.block_mozAddonManager -> true

RegEx: My Greatest Fear

Published on 2023-01-30 in Linux

Regex, Sed, and AWK are freaks in programming but they are pretty simple, well not at the beginning though.

Here I summarize some of the most amazing ones for RegEx

To Be or Not To Be, is possible with: LookAround
Stop Worrying! Regex101 is all you need to know

Qt MSVC vs MinGW in Windows

Published on 2022-12-31 in Software, Windows

I starting to use WinRT with Qt today and now after long time with MinGW, I’m switching to MSVC in Windows. Here is why

MinGW is opensource but deep down if you are in Win32, MSVC compiler always offers better API compatibility
WinRT is available only on MSVC
MSVC is better with memory control access management using SEH which MinGW doesn’t offer
MSVC offers pdb files That can help you if your program crashes. Then you can generate the core dump and debug using WinDbg
If you ever get around to some dll that simply doesn’t work with your project, it’s because MinGW and MSVC ABI are not the same. and probably that DLL was compiled by MSVC not MinGW. Same OS and still a different ABI, sounds too Windowsy to me
Because you are on Windows, show some support to the closed-source community!

COM Object and C++

Published on 2022-07-31 in Software, Windows

• CoInitialize:

Initializes the COM library for use by the calling thread, sets the thread’s concurrency model, and creates a new apartment

• CoInitializeEx: More advanced version CoInitialize that specify the thread’s concurrency model

• CoUninitialize:

Should be called on deconstructor

And Bash Is Awesome!!!

Published on 2022-07-08 in Linux

Here I list cool bash tricks I learned:

– Bash Heredoc

Chrome DevTools Remote Control in Linux Bash

Published on 2022-05-06 in Linux

Ok the title is a bit long but why google create such a nice debug interface and make it so difficult to access it.

1. open chrome with remote debug enabled

chromium --remote-debugging-port=9222 https://github.com/

2. Install websocat to create websocket to chrome

sudo pacman -S websocat

3. Find magic chrome ws url. To do that visit following url

http://127.0.0.1:9222/json/list

4. Connect to the websocket

websocat ws://127.0.0.1:9222/devtools/browser/<GUID>

5. Execute magic command. Here just scrolling the page

{"id": 1, "method": "Runtime.evaluate", "params": {"expression": "document.documentElement.scrollTop = 600"}}

Few Notes

Websocket URL directly from chrome(stdout) don’t address any target page. Stick to http://127.0.0.1:9222/json/list or see cdp tutorial for further information.

For automated command execution in debug session you can use following scripting

chrome_loop.sh
inotifywait -q -m -e close_write cmd | 
while read -r filename event; do 
     cat cmd | websocat -n1 ws://127.0.0.1:9222/devtools/page/<GUID>
done

cmd
{"id": 1, "method": "Runtime.evaluate" , "params": {"expression": "alert('hi')"}}

Kaldi Confidence Score

Published on 2022-04-30 in Speech Recognition

To calculate word level confidence score Kaldi uses a method called MBR Decoding. MBR Decoding is a decoding process that minimize word level error rate (instead of minimizing the whole utterance cost) to calculate the result. This may not give the accurate result but can be use to calculate the confidence score up to some level. Just don’t expect too much as the performance is not well-accurate.

Here are some key concepts:

1. Levenshtein Distance: Levenshtein Distance or Edit Distance compute difference between two sentences. It computes how many words are different between the two. Lets say X and Y are two word sequence shown below. The Levenshtein distance would be 3 where Ɛ represent empty word

To calculate the Levenshtein distance you can use following recursive algorithm where A and B are word sequence with length of N+1

As in all recursive algorithm to decrease amount of duplicate computation Kaldi used the memoization technique and store the above three circumstances in a1, a2 and a3 respectively

2. Forward-Backward Algorithm: Lets say you want to calculate the probability of seeing a waveform(or MFCC features) given a path in a lattice (or on HHM FST). Then the Forward-Backward Algorithm is nothing more than a optimized way to compute this probability.

3. Gamma Calculation: TBA

4. MBR Decoding: TBA

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