What is Statistics

Hello all,

I plan to start a series of tutorials in Data Analysis and SQL and it all starts with introduction to statistics as follow ..

ًWhat is statistics ?

Statistics is a science (close to and uses mathematics) with huge interest of understanding and learning from data, specially big amount of data.

Activities in statistics science include collecting, organizing, analyzing and interpreting data, making inferences, probabilities and expectation from data.


Why do we study statistics ?

The main big reason is that it helps us in decision making bY answering important questions, producing results (conclusions) or predicting information that we can build trustable decision over it.


Let me give you some beautiful insights about what statistics do for us.:


  • If we have marks of Math for students in a classroom. Knowing 1 value in statistics called “range” can tell you that between all students there is no mark greater than any other mark in the class with value more than  5. This can give you better understanding of your students marks that marks are close to each others enough.


  • With statistics you can predict the price of your house based on information about prices in the area of other houses that have some common/different attributes
  • If we have data about salaries of all people in a city. Statistics can tell you that 75% of salaries in the city lies between 1000 and 1500 so if you are going to price your product it should fit in that range.
  • In telecommunication, If you have data about people calls and duration, statistics can give you information like those segment of customers always spend more than 1000 minutes per week. You can use this to make special marketing package for them with better price to guarantee their loyalty.


Those are tiny examples of what statistics can do for us. There are much much more. Specially in the inferencing/predicting part. Take for example giving the probability of some disease for some person, or predicting student marks in an exam based on previous indicator.


I hope you got the sense of what statistics is and what it can do for us. Next part we start digging in.

CSys Electronics Recommended Books

Salam 3lykom w ra7mat Allah,

If you are interested in hardware and want to work in the hardware or embedded systems field, you have to study electronics well.C and C++ is a must,
and you may also Study JAVA to be qulaified for work positions related to CSYS dept.

Recommended Books to help you in Studying Electronics:

Book1: Electronics Fundamentals, Floyd

Book2: Electronic Devices , Floyd

CLick on the Book name and in the page Click TOC in the upper left corner for the content.

other useful web pages in this post

see this Ad:

In shaa Allah I will post the useful things related to CSys department in this blog in non-regular basis.

about CSys Department

Salam 3lykom W ra7mat Allah,
Here I will talk little about CSys department for whom want to join it or still thinking…

Simply, CSys is about the integration between programming and hardware, how computer systems are built and building computer networks.

Computer System : means a system contains Processor, some sort of memory and some peripherals built and programmed to do a specific task.

What task ?

Tasks are mainly control tasks like controlling a production line, controlling some motors doing some jobs, reading data from sensors in an environment and pass it to other equipments or taking decisions based on this data.

you may also build systems that utilize your PC to control other systems; you job here will be the interfacing between the PC and those equipments, how to control them, send data to them or read from.

What will you learn inside CSys department courses ?

First Semester :

1- Microprocessor-based Systems :
—-> The proposed target for this course is to be able to design a computer system by choosing your microprocessor, your memory, your output devices, connecting them together and programming them to do some task. note: Try to reach this target by your self if your instructor didnt help you to do so.

  • you will study the architecture of the micropreocessor (internal registers, buses, interrupts, direct memory access (DMA),
  • how to interface a microprocessor with memory
  • how interface a microprocessor with input/output devices
  • how to program the microprocessor ( in assembly)

In Lab: you will see the hardware componnets and learn how to connect them

2- Computer Networks
you will learn the basic of computer networks, how to build a computer network and programming application to work over network (say chat application)

In Lab
:you will study the CCNA certificate topics which include how to build and configure a small – to – medium computer network.by the way , it isn’t just connecting the cables and configuring the pc ip address, there are many and many to do in network.

3-Digital Signal Processing
you will study Signals from the mathematics prospective. signals are functions having some paramters and by changing the parameters you may affect the signal and so doing the magic with just a few numbers. note : Try to have this point in your mind as you may not feel it during the course lectures.

In Lab
: you will study practical examples for applying this mathematics and will solve some problems.
one project we made was Sound and Image effects Package.you choose image and apply effects on it also the sound (echo – multi echo … etc.) and it was very interesting .

4- Data Communcation

you will study how data are tansmitted via a medium. what are these mediums, how data are encoded and decoded to be transmitted and how to control the transmission errors.

In Lab
: you will solve some problems from the subject book.

5- Selected Topic: (High Performance Computing – HPC)
Imagine if you have a computationaly intensive problem (problem with huge number of computaions required) , If you tried to solve it using your PC , it may take days.How to overcome this problem by studying the concept of parallel computing is the target of this course.
Course link here

In Lab:you will study how to program a parallel application in c++ using a library called MPI-CH. This targets the following: if you have a problem and want to solve it in parallel then you designed its parallel solution and want to prgram it .. how to write the code utilizing this library (MPI-CH)
Also there was an interesting project for designing and implemeting a real hardware circuit for 1-bit pattern matching (you will learn about it in the course) but we designed the circuit in a software called Eagle and made its PCB (printed circuit board) like this and this , you will learn how to make a circuit like this and will make it in shaa Allah.


Second Term:

1- Embedded Systems
—> in Microprocessor-based system, you will not have the chance to build a real system or even see or know about. here in Embedded System, it’s totally diffrent. You have a real systems, have a real component, programming a real Microcontroller and see actual runing systems.
read this post to know what’s an embedded system

– Microcontroller concepts and Archittecture (microcontroller is a simple processor with memory and i/o pins included in the same chip).you will study the 8051 microcontroller
– Interface this microcontroller with LCDs , Motors , sensors ..etc
Complete Lab Syllabus here and projects you can make in this course here and other projects here

2- Computer Peripherals
interesting easy subject teaches you how to interface your pc with the outside world.

– Parallel Port Interfacing ( means how to use your PC parallel port to control some device such as a lamp or motor ) . you can see here a description for parallel port and here a project build using parallel port

– Serial Port Interfacing
– USB interfacing (not in deep)
– Interfacing motors and LCDs using these ports

ther is also a project here utilizing the serial port

In Lab:
you may apply this concepts and make a real implemetation utilizing the usage of this ports like controlling LCD from parallel port or moving a motor.

3- Parallel Architecture
beside the topics of the high perfomance computing in the first term add to them the study of the architecture of parallel machines and parallel search and graph algorithms.
Course Link here

In Lab: you will study many things
2- MPI again
3- some Computer Vision concepts

4- Computer Security
studying the Encryption and Decryption techniques used to encrypt/decrypt data during their transmission. you will study and implement this techniques in the course
In Lab : solving some problems of the book and explaining some others

5-Selected Topics
some different copmanies teach us some new technologies and tools to make you little close to the market. This offer is by the ITI

Just Choose the department you like and want to study its subjects.

Transistor Design

Transistor Design … Simple Approach

The following is a rundown of how to design simple NPN transistor circuits.
Basically, a transistor sets the Collector current (Ic) to be equal to the Base current (Ib) multiplied by the transistor’s Gain “Hfe” (typically around 100). [IC = Ib*Hfe]

This lets you turn a large device (such as a motor or a Laser) from a small signal (such as from a microcontroller or a sensor). However, the transistor also requires a voltage Vbe between its Base and Emitter (typically around 0.7V). Here is an example circuit:

1st step is to determine how much current & power your load will take. If the load is a Laser or a Relay, then it should only be about 100mA at 5 or 12V, which is upto 1.2Watts (Power = Volts * Current).

2nd step is to determine the maximum Base current (Ib) you will have. If the Base resistor (Rb) is connected to a microcontroller, then this is generally a maximum of 20mA (enough to power a simple LED but not much more).

From these 2 steps you should find a transistor that has Max Collector Current (Ic) and Max Power Dissipation (Pd) ratings that are atleast twice your requirements (for safety), and has a DC Gain (Hfe) large enough to convert your Ib into your Ic. To amplify small signals or to turn on a small Relay / Motor / Laser under 100mA using a microcontroller, use a small transistor (eg: BC548) in the TO-92 package, but for any larger currents or power you will need a larger transistor (eg: TO-220 package), possibly with a metal heatsink.

3rd step is to determine the Base resistor value (Rb) to give the correct voltage Vbe (typically around 0.7V) for the transistor, based on what you are connecting it to. Use Ohm’s Law (V=I*R) to work out the resistor that would give you the desired current (Ib) between the resistor’s voltages (Vin and Vbe). Ideally, Ic = Hfe * Ib = Hfe * (Vin – Vbe) / Rb. However, transistors aren’t perfectly linear amplifiers, so you wont get quite this much current output.

When you are trying to either switch something to be completely ON or completely OFF (which is a good idea for Relays, Lasers and Motor PWM), then you want to use the transistor at its “Saturation” limits, which means making Ib about twice as much as you originally calculated, so that it is definitely ON or OFF. In these cases, you can think of the transistor as a switch, that is open (not letting any current through, therefore Vce = Vcc) when Ib = 0, and closed (letting all the current through, therefore Vce = 0 or ‘short circuit’) when Ib = max. Just be aware that even when you have saturated the transistor on (Ib is max), Vce wont actually reach 0volts, but will usually be between 0.2 – 0.7V depending on the transistor.

Transistor Leads:


Why Pullup Resistors ?

The Pull-up Resistor

This time in Very Basic Circuits, I would like to talk about pull-up resistors. The basic function of a pull-up resistor is to insure that given no other input, a circuit assumes a default value. Actually, there are two flavors of this circuit. A pull-up and a pull-down. Their function is the same, to create a default value for a circuit, but one pulls the line high, the other pulls it low.

A floating input gate. Not Good!

Consider this schematic. The gate U1A has an input (pin 1) and an output (pin 2). The input state of most logic gates is called a high impedance. This means it provides no real power of its own. Therefore, if nothing is connected to pin 1, the value of the input is considered to be floating. Most gates will float towards a high state. This is a very weak condition, and any electrical noise could cause the input to go low.

When switch S1 is closed (on), the input state at pin1 goes low. Since there is a definite connection to an electrical potential (in this case ground), the state of the pin is stable.

When switch S1 is open (off), then input pin 1 is susceptible to a wide array of electrical problems. The traces or wires connected to pin 1 may very well allow enough electrical noise in (by acting as little antennas) to cause pin 1 to incorrectly switch states. What is needed here is a way to connect pin 1 to an electrical potential that can be removed when the switch is closed. This electrical potential will allow the pin to keep a steady state.

One thought is to tie the pin to Vcc (+5 volts) to insure that pin 1 doesn’t float. The circuit to the right certainly does that. With pin 1 tied directly to Vcc, the line does not float, and has an ON state.

The problem with this circuit is what happens when switch S1 is closed. This creates a direct electrical connection between Vcc and GND. In other words, it will short out the circuit. If you are lucky, it will just stop your entire system from working. If you are unlucky, it will burn up the wires!

The problem with short circuits is they allow too much current to flow from Vcc to GND. This causes heat to be generated, which can sometimes burn parts, wires, or even start fires. In addition, most circuits fail to function correctly because the voltage at the power supply drops to zero. In general, this is a bad situation!

A very bad idea!

Pull-up resistor limits the current

Now consider the next schematic, which is similar to the first but has added a pull-up resistor. This resistors function is to limit the amount of current that can flow through the circuit.

When switch S1 is open (off), pin 1 is tied to Vcc through the resistor. Since pin1 is a high impedance input, a voltage meter or logic probe placed on pin 1 will show Vcc (+5v) if connected to pin 1.

When switch S1 is closed (on), pin 1 has a direct connection to GND, which takes it to the low state. The pin1 side of R1 also has a direct connection to ground. Current will flow from Vcc, through R1, and to ground. It isn’t considered a short, however, because R1 will limit the amount of current that can flow to a very small amount. In fact, you can compute this using Ohms law.

I = V / R

I = 5v / 10,000ohms

I = .0005A (.5mA)

A variation on this them is a pull-down resistor. Just like the pull-up resistor, it is used to limit the current that can flow between Vcc and ground. Though less often used, it is still a valid thing to do.

Most digital circuits use a 10k or a 47k resistor for pullups. The exact value doesn’t actually matter, as long as it is high enough to prevent too much current from flowing. 10k seems to be the most common, but if you are hoping to save as much power as possible, the a 47k resistor may be right for your application. In some cases, you can go higher, but then you are depending on characteristics of the pins on the chip.

In Summary

You will find that pull-up resistors are extremely common is most digital circuits. The key function for a pull-up is to prevent input lines from floating. The key function for the resistor itself is to prevent too much current from flowing through the pull-up circuit.



Control Your PC Via Remote Control

Hi All ,

This is another project I made and want to share.

Description :

with the help of this project you can control your PC via a remote control (any remote control , e.g. you TV remote). Controlling the PC means you can open and close programs , Increase or decrease the Volume , showing your powerpoint presentations , switching between songs and movies …. etc, all while you are away from your PC (using your remote).

You can program the remote buttons as you want to do any selected task.


using an infrared receiver and program the signals received from it.

the circuit connected to the PC via serial port.

Pictures :







Electronics Helpful Websites

Welcome to the Electronics Club

Link : http://www.kpsec.freeuk.com/index.htm
My Rating : Excellent
Description :-
Helps IN :
If you are Looking for Tutorial That help You in the following

– How To Solder and How to build electronic circuits and understanding circuits diagrams
– Contain excellent explanation to some electronic components and how to connect and test them such as Resistors ,Capacitors , transistors , relays , switches ,LEDs

– Contain explained projects that make you practice
such as Drive a LED , Traffic light generator , dice , and more here


Understanding Electronics Components
link : http://www.mikroe.com/en/books/keu/00.ht

Description :-
teaches the basic components and how the are used in circuits starting with resistors till transistors and ICs and other components like speakers and microphones .It also include some practical circuits using these components

Helps IN:
If you want t to start electronics fast without going into more details ,laws, calculations and so on .
it also helps as a revision if you studied electronics before and want to revise basics in a fast way.

added: 20-8-2008


doctronics Educational Publishing for Design & Technology