Ahmed Ghazey

Hello all, Sigmoid Function or Logistic Function , it is used in Machine Learning problems for the purpose of learning (Neural network ) on curves. its range between ]0,1[ it is horizontal asymptotic on 0 and 1, because of its range between 0 and 1 it is used in classification using threshold for example if we take 0.5 as a threshold  values greater than 0.5 are considered Ones and  values less than or Equal  0.5 considered 0. it has the following formula :   and it shape as following : from wikipedia  so it accept differentiation over its domain unlike Step Function. differentiation of sigmoid function :  I finished the article , i hope you understand it . Thanks for your time and effort if you like it share and follow me :)

SA one of my objectives for this article making you curios to know about XML , and make you search the web for more info about it , and i hope do that , lets start. what is XML stand  for ? e X tensible  M arkup L anguage. it is used to transport data over the internet , you can invent your own tags , no restriction . for example if you want transport data for weather news: < weathernews > < new > < city > Cairo < / city > < max >36< / max > < min > 22 < / min > < / new > < / weathernews > XML   consist of main three component : tagged elements. attributes. text. lets see example: < bookstore > < book category="CHILDREN" > < title lang="en" > Harry Potter< /title > < author>J K. Rowling< /author > < year >2005< /year > < price>29.99 < /price > < /book > < book category="WEB" > < title lang="e

Salmo Aliko . today I'll write about Machine Learning  , it is interesting topic. I put assumption I'm talking to computer since students. first of all , many of us dreamed to make robot, auto detection for missiles and treat it automatically and many awesome dreams, but we didn't know how achieve it. let me start with the definition and mentioning some of ML -M achine L earning -  applications . What is Machine Learning?   is the ability to learn without being explicitly programmed   and if we like mentioning more formal definition it is   A computer program is said to learn from experience E with respect to some class of tasks T and performance measure P, if its performance at tasks in T, as measured by P, improves with experience E. application of ML : Computer Vision. Natural Language Processing. Game playing. Market segmentation. Medical Diagnosis.   Stock Market Analysis. Search Engines. Robotics. One word describing this applications just "

Al Salmo Aliko . Hello, in this post I'll discuss with you how to design good Entity Relationship Diagram ERD . this article for: IT Students learning about database. you are having difficulties in creating ERD. you are developer that need help in database design.   let's ask ourselves Why good database design is good ? or why we need ERD?         when I started programming Eng / Eman Ahmed was my First teacher, she said you must write your code with pen, and now I told you good database design start with paper and pen or in technological terms start with ERD, ERD is the model which shows logical layout of your database. let's List some advantages of good database design : very low or no redundant data is stored.  supporting planed or unplanned queries. good design easy to maintain and modify. from first glance you can understand it. an ERD consist from Entities and relationships between them; there exist many notation in textbooks and all are right I

I faced many problems when installing OpenCV on eclipse, so I decide write this tutorial . I'll explain steps in Order : 1- Open eclipse create new empty project (C or C++ project). 2- make sure that  "MinGW"  toolchain is selected . 3- press next . 4- right click on project -> properties . 5-Under "C/C++build "  section select -> setting , then select "tool setting " tab, Then select the "Includes" folder (on older versions of eclipse it is the "Directories" folder) in the GCC Compiler branch and add the opencv include directory to Include paths (-I): "C:\OpenCV2.1\include\opencv\", of course you have to change the directory if you install OpenCV in another place. 6- Now, under the MinGW Linker select the "Libraries" folder and add the following to the Libraries (-l) section (note not all of these are necessarily needed for your project but these are all the libraries available in opencv. cv2

SA I write this post because I failed yesterday to solve the topcoder TCO 250 problem , it was about find the LCM -Least Common multiple -simply it is smallest number which accept the division on - non zero - numbers . how we calculate it? there exist two ways lets discuss both: for example 3,4,6 first way find the multiple of all numbers 2,3,4...etc. Multiples of 2: 4,6,8,10, 12 ,14,16. Multiples of 3: 6,9, 12 ,15. Multiples of 4: 8, 12 ,16,20. as you see 12 is the smallest common number which appear on all numbers . second way factor each number into it prime component and do the following steps : 1-Count the number of times each prime number appears in each of the factorizations. 2-For each prime number, take the largest of these counts. 3-Write down that prime number as many times as you counted for it in step 2. 4-The least common multiple is the product of all the prime numbers written down. example 5,6,15. Factor into primes Prime facto

Hi this is my first technical post , really i find this topic very interesting and i like it . actually I worked now on good project which utilize my Genetic algorithms , neural networks and parallel computing knowledge . when searching i hit in this topic . pointers to function : who should read this article are computer science students and programing Students introduction :  you can write good code without knowing any thing about pointers , but if you used pointers you will write all your codes with pointers , it is best invention after electricity , it will attract you , and you will feel the infinite happiness  . what is pointer ? you know int , float , double you can think on this data type as box which contain some value . but pointers is different it stores the reference of this value -memory address - then you can access the value in this pointer by dereference it . declare pointer int *ptr; dereference pointer *ptr ; but take care you have to assign value to the p