Dec 09

Mysql: Repair database and/or tables

"
mysqldump db_name t1 > dump.sql mysql db_name < dump.sql

mysqldump db_name > dump.sql mysql db_name < dump.sql

mysqldump –all-databases > dump.sql mysql < dump.sql

ALTER TABLE t1 ENGINE = InnoDB;

REPAIR TABLE t1;

mysqlcheck –repair –databases db_name … mysqlcheck –repair –all-databases

"

Reference: https://dev.mysql.com/doc/refman/5.7/en/rebuilding-tables.html
—

Sayed Ahmed

BSc. Eng. in Comp. Sc. & Eng. (BUET)
MSc. in Comp. Sc. (U of Manitoba, Canada)
MSc. in Data Science and Analytics (Ryerson University, Canada)
Linkedin: https://ca.linkedin.com/in/sayedjustetc

Blog: http://Bangla.SaLearningSchool.com, http://SitesTree.com
Online and Offline Training: http://Training.SitesTree.com

Get access to courses on Big Data, Data Science, AI, Cloud, Linux, System Admin, Web Development and Misc. related. Also, create your own course to sell to others to earn a revenue.
http://sitestree.com/training/

If you want to contribute to the operation of this site (Bangla.SaLearn) including occasional free and/or low cost online training (using Zoom.us): http://Training.SitesTree.com (or charitable/non-profit work in the education/health/social service sector), you can financially contribute to: safoundation at salearningschool.com using Paypal or Credit Card (on http://sitestree.com/training/enrol/index.php?id=114 ).

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Dec 09

Magento 2: Indexing Options

sudo php bin/magento indexer:info
design_config_grid Design Config Grid
customer_grid Customer Grid
catalog_category_product Category Products
catalog_product_category Product Categories
catalogrule_rule Catalog Rule Product
catalog_product_attribute Product EAV
cataloginventory_stock Stock
inventory Inventory
catalogrule_product Catalog Product Rule
catalog_product_price Product Price
scconnector_google_remove Google Product Removal Feed
scconnector_google_feed Google Product Feed
catalogsearch_fulltext Catalog Search—

Sayed Ahmed

BSc. Eng. in Comp. Sc. & Eng. (BUET)
MSc. in Comp. Sc. (U of Manitoba, Canada)
MSc. in Data Science and Analytics (Ryerson University, Canada)
Linkedin: https://ca.linkedin.com/in/sayedjustetc

Blog: http://Bangla.SaLearningSchool.com, http://SitesTree.com
Online and Offline Training: http://Training.SitesTree.com

Get access to courses on Big Data, Data Science, AI, Cloud, Linux, System Admin, Web Development and Misc. related. Also, create your own course to sell to others to earn a revenue.
http://sitestree.com/training/

If you want to contribute to the operation of this site (Bangla.SaLearn) including occasional free and/or low cost online training (using Zoom.us): http://Training.SitesTree.com (or charitable/non-profit work in the education/health/social service sector), you can financially contribute to: safoundation at salearningschool.com using Paypal or Credit Card (on http://sitestree.com/training/enrol/index.php?id=114 ).

Affiliate Links: Deals on Amazon :
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Hottest Deals on Amazon CA: http://tiny.cc/bgnddz

Hottest Deals on Amazon Europe: http://tiny.cc/w4nddz

Dec 09

Magento 2: Reset indexes

Reset indexes if index reindexing causes issues. All possible combinations for native indexes:

"

bin/magento indexer:reset design_config_grid; bin/magento indexer:reset customer_grid; bin/magento indexer:reset catalog_category_product; bin/magento indexer:reset catalog_product_category; bin/magento indexer:reset catalogrule_rule; bin/magento indexer:reset catalog_product_attribute; bin/magento indexer:reset cataloginventory_stock; bin/magento indexer:reset catalog_product_price; bin/magento indexer:reset catalogrule_product; bin/magento indexer:reset catalogsearch_fulltext;

Reference:https://mirasvit.com/knowledge-base/magento-2-reindex-error-locked.html

Dec 08

posted by rafiq

The video is created by Sayed. Rafiq (contractor of Justetc/8112223 Canada Inc.) just bought this from our old site to this site. [All articles where it says: Posted by Rafiq — just mean Rafiq is not the author/creator/writer/in the video — he just did the data entry]

—

Sayed Ahmed

BSc. Eng. in Comp. Sc. & Eng. (BUET)
MSc. in Comp. Sc. (U of Manitoba, Canada)
MSc. in Data Science and Analytics (Ryerson University, Canada)
Linkedin: https://ca.linkedin.com/in/sayedjustetc

Blog: http://Bangla.SaLearningSchool.com, http://SitesTree.com
Online and Offline Training: http://Training.SitesTree.com

Get access to courses on Big Data, Data Science, AI, Cloud, Linux, System Admin, Web Development and Misc. related. Also, create your own course to sell to others to earn a revenue.
http://sitestree.com/training/

If you want to contribute to the operation of this site (Bangla.SaLearn) including occasional free and/or low cost online training (using Zoom.us): http://Training.SitesTree.com (or charitable/non-profit work in the education/health/social service sector), you can financially contribute to: safoundation at salearningschool.com using Paypal or Credit Card (on http://sitestree.com/training/enrol/index.php?id=114 ).

Affiliate Links: Deals on Amazon :
Hottest Deals on Amazon USA: http://tiny.cc/38lddz

Hottest Deals on Amazon CA: http://tiny.cc/bgnddz

Hottest Deals on Amazon Europe: http://tiny.cc/w4nddz

Dec 08

Insert Products into Magento Programmatically

Magento 2 – how to add products in Magento using REST API and C #

https://www.iperiusbackup.net/en/magento-2-data-load-through-rest-api-interface-and-c/

magento-2-create-product-programmatically.html

https://www.mageplaza.com/devdocs/magento-2-create-product-programmatically.html

insert product programmatically

https://magento.stackexchange.com/questions/62036/insert-product-programmatically

Programmatically (manually) creating simple Magento product

https://inchoo.net/magento/programming-magento/programatically-manually-creating-simple-magento-product/

By

Sayed Ahmed

BSc. Eng. in Comp. Sc. & Eng. (BUET)
MSc. in Comp. Sc. (U of Manitoba, Canada)
MSc. in Data Science and Analytics (Ryerson University, Canada)
Linkedin: https://ca.linkedin.com/in/sayedjustetc

Blog: http://Bangla.SaLearningSchool.com, http://SitesTree.com
Online and Offline Training: http://Training.SitesTree.com

Get access to courses on Big Data, Data Science, AI, Cloud, Linux, System Admin, Web Development and Misc. related. Also, create your own course to sell to others to earn a revenue.
http://sitestree.com/training/

If you want to contribute to the operation of this site (Bangla.SaLearn) including occasional free and/or low cost online training (using Zoom.us): http://Training.SitesTree.com (or charitable/non-profit work in the education/health/social service sector), you can financially contribute to: safoundation at salearningschool.com using Paypal or Credit Card (on http://sitestree.com/training/enrol/index.php?id=114 ).

Dec 06

Python Machine Learning Codes

Sebastian Raschka has shared the codes for his upcoming book "Python Machine Learning – 3rd Edition" in the below github repository. https://lnkd.in/ex7J-EY

Dec 06

Administering Magento 2 on AWS Platform

Varnish:
Configuring Varnish Server i.e. a Cache Server
https://varnish-cache.org/docs/5.1/reference/varnishd.html#http-resp-hdr-len

/opt/bitnami/varnish/varnishd

varnishd [-a address[:port][,PROTO]] [-b host[:port]] [-C] [-d] [-F] [-f config] [-h type[,options]] [-I clifile] [-i identity] [-j jail[,jailoptions]] [-l vsl[,vsm]] [-M address:port] [-n name] [-P file] [-p param=value] [-r param[,param…]] [-S secret-file] [-s [name=]kind[,options]] [-T address[:port]] [-t TTL] [-V] [-W waiter] [-x parameter|vsl|cli|builtin] [-?]

—

How to fix 503: Backend Fetch error
Give it a try; no guarantee. Purge Varnish cache as well. magento cache clearing also causes varnish cache Purge
https://community.magento.com/t5/Magento-2-x-Programming/how-to-fix-Error-503-Backend-fetch-failed/td-p/84061

—-

Configure And Use Varnish (TM)

See if your version and platform is right before applying
https://docs.bitnami.com/bch/apps/wordpress/administration/configure-use-varnish/

Deploy content

setup:static-content:deploy [-f|–force] [-s|–strategy [STRATEGY]] [-a|–area [AREA]] [–exclude-area [EXCLUDE-A
REA]] [-t|–theme [THEME]] [–exclude-theme [EXCLUDE-THEME]] [-l|–language [LANGUAGE]] [–exclude-language [EXCL
UDE-LANGUAGE]] [-j|–jobs [JOBS]] [–max-execution-time [MAX-EXECUTION-TIME]] [–symlink-locale] [–content-versi
on CONTENT-VERSION] [–refresh-content-version-only] [–no-javascript] [–no-css] [–no-less] [–no-images] [–no
-fonts] [–no-html] [–no-misc] [–no-html-minify] [–] [<languages>…]

By

Sayed Ahmed

BSc. Eng. in Comp. Sc. & Eng. (BUET)
MSc. in Comp. Sc. (U of Manitoba, Canada)
MSc. in Data Science and Analytics (Ryerson University, Canada)
Linkedin: https://ca.linkedin.com/in/sayedjustetc

Blog: http://Bangla.SaLearningSchool.com, http://SitesTree.com
Online and Offline Training: http://Training.SitesTree.com

Get access to courses on Big Data, Data Science, AI, Cloud, Linux, System Admin, Web Development and Misc. related. Also, create your own course to sell to others to earn a revenue.
http://sitestree.com/training/

If you want to contribute to the operation of this site (Bangla.SaLearn) including occasional free and/or low cost online training (using Zoom.us): http://Training.SitesTree.com (or charitable/non-profit work in the education/health/social service sector), you can financially contribute to: safoundation at salearningschool.com using Paypal or Credit Card (on http://sitestree.com/training/enrol/index.php?id=114 ).

Affiliate Links: Deals on Amazon :
Hottest Deals on Amazon USA: http://tiny.cc/38lddz

Hottest Deals on Amazon CA: http://tiny.cc/bgnddz

Hottest Deals on Amazon Europe: http://tiny.cc/w4nddz

Dec 05

Find answers to the questions to know more on Radar. Sure, you can apply the knowledge in sel-driving car engineering?

What is echo signal in radar?
"Noun. 1. radar echo – an electronic signal that has been reflected back to the radar antenna; contains information about the location and distance of the reflecting object. electronic signal – a signal generated by electronic means. Radar echo – definition of radar echo by The Free Dictionary" https://www.thefreedictionary.com › radar+echo

How does power density of the echo signal differ from the received power by the radar? Conceptually and in the equations?
Ans: Ae = effective area of the receiving antenna

What is the relation between G (Gain in the direction of target) and Ae? Any explanation of the equation and relation?

What are the units of the parameters in the equations?

What is the symbol used for Wavelength?

How do you calculate the distance beyond what the target cannot be detected? i.e. Rmax, give the equation and explain

How can you achieve a long distance?

To get a long distance, will Pt need to be large?

To get a long distance, will radiated energy need to be concentrated into a narrow beam?

To get a long distance, will the received energy must be collected with a large antenna?

To get a long distance, will the receiver must be sensitive to weak signals?

Is the predicted radar range very accurate or usually optimistic? why or why not?

What are the parameters that can make the predicted radar range not very accurate?

Can you describe the maximum range of a Radar just by one number?

Is it true? radar range (max) must include probability, the target type, and range possible

What are the unpredictable or statistical parameters in the equation for max range?

Is Smin = minimum detectable signal predictable in the equation?

Is target cross section (sigma) predictable in the equation?

Are meteorological conditions predictable in the equation?

What do you mean by Smin = minimum detectable signal ? Any little details in any direction?

Is Smin = minimum detectable signal: affected by noise energy?

Does Smin = minimum detectable signal: also depend on the threshold set at the output of the receiver? Why is the threshold there? What happens if you lower the threshold? Does low threshold mean less perfection?

Where does noise in the receiver originate from? Can the receiver itself introduce noise? What can be different sources of noise?

What is thermal noise power? Give the equation. Explain the concept and the equation. k* T * Bn, T in kelvin

Half-power bandwidth? Noise bandwidth? 3-DB bandwidth : what are these? What is the relation with Bn or thermal noise power if any?

What are the different sources of noise?
Galactic, Solar, Atmosphere, man made, Ground, Receiver

True or false? Noise entering the filter is Gaussian

How does Rayleigh relates to the probability density of a narrowband IF filter?

Probability of false alarm: what is the equation? What is the relation with TNR (Thermal noise ratio) and Bandwidth? Give a diagram.

By

Sayed Ahmed

BSc. Eng. in Comp. Sc. & Eng. (BUET)
MSc. in Comp. Sc. (U of Manitoba, Canada)
MSc. in Data Science and Analytics (Ryerson University, Canada)
Linkedin: https://ca.linkedin.com/in/sayedjustetc

Blog: http://Bangla.SaLearningSchool.com, http://SitesTree.com
Online and Offline Training: http://Training.SitesTree.com

Get access to courses on Big Data, Data Science, AI, Cloud, Linux, System Admin, Web Development and Misc. related. Also, create your own course to sell to others to earn a revenue.
http://sitestree.com/training/

If you want to contribute to the operation of this site (Bangla.SaLearn) including occasional free and/or low cost online training (using Zoom.us): http://Training.SitesTree.com (or charitable/non-profit work in the education/health/social service sector), you can financially contribute to: safoundation at salearningschool.com using Paypal or Credit Card (on http://sitestree.com/training/enrol/index.php?id=114 ).

Affiliate Links: Deals on Amazon :
Hottest Deals on Amazon USA: http://tiny.cc/38lddz

Hottest Deals on Amazon CA: http://tiny.cc/bgnddz

Hottest Deals on Amazon Europe: http://tiny.cc/w4nddz

Dec 04

Radar Equations

Describe/Explain Radar operation? i.e. for example, how is radar used to detect an aeroplane? Show radar components and how they function to detect an aeroplane and how is the distance calculated https://www.explainthatstuff.com/radar.html

What is the equation to calculate the range to a target using Radar Systems. Use speed of light in the equation. https://www.radartutorial.eu/01.basics/Distance-determination.en.html
R = c * Tr/2 , c = speed of light, Tr = travel time back and forth
R in km = 0.15 * Tr (in micro sec) , speed of light = 150 meters in 1 microsecond
c = 3 * 10 to the power 8 m/s = 3 * 100 = 300 m/ micro sec = 0.3 km/ micro sec

What is the maximum unambiguous range? c * Tp/2 = c / (2 * freq)
Tp = Pulse repetition interval
Freq = 1/Tp or Tp = 1/f

What are the factors that influence the performance of Radars?

Does Antenna gain influence radar performance? if so why and how? May be explain with equations in addition to giving conceptual explanation

Does Antenna effective aperture influence radar performance? if so why and how? May be explain with equations in addition to giving conceptual explanation

Does Transmitter power influence radar performance? if so why and how? May be explain with equations in addition to giving conceptual explanation

Does System losses influence radar performance? if so why and how? May be explain with equations in addition to giving conceptual explanation

Does Radar cross section influence radar performance? if so, why and how? May be explain with equations in addition to giving conceptual explanation

What is the power density for Radars? Does it relate to receiver anyway? Can you give equations for power density for directive and isotropic antennas?

What is the uncommon parameter in the equation of power density for directive and isotropic antennas?

How do you calculate average transmitter power from Peak power?

Is average power a function of pulse width (tau), Tp – pulse-repetition period?

What is the power density of the echo signal?

By


Sayed Ahmed

BSc. Eng. in Comp. Sc. & Eng. (BUET)
MSc. in Comp. Sc. (U of Manitoba, Canada)
MSc. in Data Science and Analytics (Ryerson University, Canada)
Linkedin: https://ca.linkedin.com/in/sayedjustetc

Blog: http://Bangla.SaLearningSchool.com, http://SitesTree.com
Online and Offline Training: http://Training.SitesTree.com

Get access to courses on Big Data, Data Science, AI, Cloud, Linux, System Admin, Web Development and Misc. related. Also, create your own course to sell to others to earn a revenue.
http://sitestree.com/training/

If you want to contribute to the operation of this site (Bangla.SaLearn) including occasional free and/or low cost online training (using Zoom.us): http://Training.SitesTree.com (or charitable/non-profit work in the education/health/social service sector), you can financially contribute to: safoundation at salearningschool.com using Paypal or Credit Card (on http://sitestree.com/training/enrol/index.php?id=114 ).

Affiliate Links: Deals on Amazon :
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Dec 03

Artificial Intelligence to Watch

These Scientists Are Trying to Build Powerful Computers Inspired by Our Brains

https://www.bloomberg.com/news/videos/2019-10-29/these-scientists-are-trying-to-build-powerful-computers-inspired-by-our-brains-video

These Researchers Are Getting Us Closer to Making Contact with Aliens

https://www.bloomberg.com/news/videos/2019-10-29/these-researchers-are-getting-us-closer-to-making-contact-with-aliens-video

Scientists Are Racing to Eliminate the World’s Fastest Spreading Tropical Disease

https://www.bloomberg.com/news/videos/2019-10-29/scientists-are-racing-to-eliminate-the-world-s-fastest-spreading-tropical-disease-video

The U.K. Startup Trying to Change the Way the World Gets its Energy

https://www.bloomberg.com/news/videos/2019-10-29/the-u-k-startup-trying-to-change-the-way-the-world-gets-its-energy-video