How Cloud Computing Works

Cloud computing basics. 

 

The advancement of technology and encompassing networks storage and processing power led to epitome of computing. 

 

In this century it’s called cloud computing or commonly referred to as cloud. What is cloud computing? 

 

Cloud computing is a paradigm that allow on-demand network access to shared computing resources, a model for managing, storing and processing data online via the Internet. Some cloud computing characteristics include; On-demand service: 

 

You use it when you need it. Network access: Using Internet as a medium. Shared resources: Resources are pulled together and used by multiple clients. Scalability: 

 

Allows elasticity of resources. Three delivery models of cloud computing: SaaS, PaaS and IaaS. Cloud computing offers different services based on three delivery models. When arranged in a pyramid form. They follow the order of SaaS, PaaS and IaaS. 

 

What is SaaS? SaaS or software as a service. It is a service that offers on-demand pay per use of application software to users. Unlike licensed bought programs. This service is platform independent and you don’t need to install the software on your PC. 

 

The cloud runs a single instance of the software and makes it available for multiple end-users. This makes cloud computing cheap. All the computing resources responsible for delivering SaaS are entirely managed by the vendor. 

 

This service is accessible via a web browser or lightweight client applications. Who use Saas – End customers are frequent users of SaaS. Example product and services of SaaS. Popular SaaS providers offer the following products and services. 

 

The Google ecosystem such as Gmail, Google Docs and Google Drive. Microsoft Office 365, HR and helpdesk solutions and customer relationship management services such as Salesforce. Pros: Universally accessible from any platform. No need to commute you can work from any place. 

 

Excellent for collaborative working. Vendor provides modest software tools. Allows for multi-tenancy. Cons: Portability and browser issues. Internet performance may dictate overall performance. Compliance restrictions. 

 

What is PaaS? PaaS or platform-as-a-service. This service is mainly a development environment and is made up of a programming language execution environment, an operating system a web server and a database. 

 

All of this encapsulate the environment where users can build, compile and run their programs without worrying at the underlying infrastructure. In this model you manage data and the application resources. All other resources are managed by the vendor. 

 

Who uses PaaS? This is a domain for developers. Example products and services of PaaS. Cloud providers have the following as the PaaS products and services: 

 

Amazon Web Services elastic Beanstalk, Google App Engine, Windows Azure, Heroku and force.com 

 

Pros: Cost-effective rapid development. it’s scalable. Faster market for developers. Easy deployment of web applications. Private or public deployment is possible. 

 

Cons: Developers are limited to providers languages and tools. Migration issues such as the risk of vendor lock-in. What is IaaS? 

 

IaaS or infrastructure-as-a-service this service offers the computing architecture and infrastructure that is it offers all computing resources but in a virtual environment so that multiple users can access them. 

 

These resources include data storage, virtualization, servers and networking. Most vendors are responsible for managing the above for resources. If you will use this service you will be responsible for handling other resources such as applications, data, runtime and middleware Who use IaaS? 

 

IaaS is mainly for SysAdmin. Example products and services of IaaS they include Amazon EC2, GoGrrid and Rackspace.com 

 

Pros: The cloud provides the infrastructure. Enhanced scalability dynamic workloads are supported. IaaS is flexible. 

 

Cons: Security issues. Network and service delays. Examples of companies that use cloud computing. Amazon’s AWS or Amazon Web Services. When it comes to companies using cloud computing, AWS takes the lead. This cloud computing company offers IaaS and PaaS services to its customers. 

 

it’s popular for its Elastic Compute cloud EC2. Among other services such as elastic beanstalk, Simple Storage Service (S3) and relational database service or RDS. Apart from the complete suite of cloud computing. 

 

It offers other cloud related services including internet of things (IOT), cloud security and mobile services. iCloud: This cloud from Apple is majorly for Apple products and allows you to backup and store all your multimedia and other documents online. 

 

This content is then seamlessly integrated onto all your devices or apps. In case you access it from them. Microsoft Azure: This cloud is used and offered by Microsoft. It offers IaaS, PaaS and SaaS for its enterprise software and developer tools. 

 

If you have ever used Office 365 products, then you have used SaaS. Google Cloud: The Google cloud platform is a universal cloud for Google’s vast ecosystem and also for other products such as Microsoft 

 

Office it allows collaboration, storage of data and also other services offered by its cloud computing suite. 

 

IBM SmartCloud: Using Private, Public and Hybrid deployment models IBM SmartCloud provides a full range of IaaS, Paas and SaaS cloud computing services to businesses. 

 

Using pay-as-you-go model, this cloud generates revenue for IBM. 

What is Modulation

Modulation is one of the most frequently used technical words in communications technology. One good example is that of your FM radio, where FM stands for frequency modulation.

 

In this article, we are going to learn the basics of modulation techniques and see how they are applied in modern cellular and communications technology.

 

Frequency and wavelength of a wave are inversely connected. Humans have the capability to hear sound frequency from 20 hertz to 20 kilohertz.

 

But if a radio tower transmits electromagnetic waves of the same frequency, the size of the antennas required will be really high. 

 

In the antenna video we have already seen that the size of the antenna is proportional to the wavelength. If we had transmitted the electromagnetic wave in the same frequency of sound, the antenna size required would have been in the range of kilometers. 

 

This is why we need modulation. Before the electromagnetic waves are transmitted they should be modulated to a high frequency signal. We can understand the way we modulate the signals with a simple analogy. 

 

Try throwing a piece of paper, it won’t go far. Now tie it to a stone and throw it again. The second method is obviously more efficient than the first one. This is exactly how we do modulation. 

 

In place of a stone modulation uses a high frequency signal known as a carrier signal. As we know any signal has three basic properties amplitude, frequency and phase. In the modulation process, one of the properties of the carrier signal is varied in accordance with the message signal. 

 

For example, the frequency of the carrier signal is varied according to the amplitude of the message signal. This technique is known as frequency modulation. Please note that the frequency of a carrier signal is always high, which means the modulated signal is also of high frequency and energy. 

 

The value of the originalsignal can be easily retrieved from the frequency of the modulated signal. In the same way, we can also achieve amplitude modulation. 

 

Here the amplitude of the carrier signal is varied based on the value of the message signal. The modulation techniques we have discussed so far have all been analog types. 

 

However, they are already obsolete. Analog modulation is susceptible to noise, which degrades the quality of signals. And moreover, in today’selectronic instruments, all operations are carried out in digital form where the digital signals are either a one or a zero. 

 

So, let’s discuss the digital modulation techniques that are currently used. More specifically, let’s see how the digital bit flow is converted to an electromagnetic wave. 

 

The first digital technique is amplitude shift keying. Here based on the digital pulses, the amplitude of the carrier signal is adjusted. 

 

High amplitude relates to one and low amplitude relates to zero. The next technique is called frequency shift keying. Here based on the value of digital pulses, the frequency of the carrier signal is adjusted. 

 

In this case high frequency relates to one and low frequency relates to zero. The third technique is phase shift keying. Here the phase of the carrier signal is changed by 180 degrees when the digital pulse moves from one to zero or zero to one. 

 

Telecommunications technology is all about increasing data transfer speed and efficiency. But if you use any of the digital modulation techniques explained previously, you wouldn’t get a high data transfer speed. 

 

However, there is a technique in physics which if you use it means you can practically send up to six bits of information as a single electromagnetic wave. 

 

This technique is known as quadrature amplitude modulation. To understand QAM in an easy way, let’s take two analog signals. The beauty of QAM is that you can modulate these two different signals as a single signal and then transmit it. 

 

Then at the receiver end, you will be able to separate out the original signals, thereby saving bandwidth. 

 

Let’s see how this modulation is done. In QAM, the first signal is amplitude modulated using a carrier wave as shown. 

 

The second signal is also amplitude modulated with a carrier wave of the same frequency and amplitude but after giving the carrier signal a 90 degree phase shift. Now these two modulated signals are mixed together and form a single signal, wecall it a multiplexed signal. 

 

The interesting thing is that on the receiver side, we can easily separate out the original signals from the multiplexed signal. In the case of digital QAM, a similar approach is used. Here instead of analog signals, different combinations of bits are added together to produce a multiplexed signal. 

 

Let’s see how a 16 QAM works. If you are familiar with digital technology, you know that any form of data is just a collection of ones and zeros. 

 

In 16 QAM, we can pack four bits together and send it as a single electromagnetic wave. Based on the values of the four bits, this output will have different phase angles and amplitude. This means the phase angle and amplitude of the multiplex signal can completely represent four bits of data. 

 

In 16 QAM, such 16 bit values can be represented by adjusting the phase and amplitude of the multiplex signal. And this single multiplexed signal is then used for the transmission. 

 

You can see how the different amplitude and phase electromagnetic signals represent various four bits of data. Using a similar technique to that used an analog modulation, here the amplitude modulated signals are also mixed together. 

 

And finally, a single output is produced. As we have seen in this modulation two carrier signals that are out of phaseby 90 degrees are used. Hence, the word quadrature is used to refer to this technique. 

 

If instead of QAM, we had used a normal modulation technique to send bits of data we would have used for electromagnetic signals. Thus, 16 QAM increases the data transfer speed by four times. Scientists have even achieved 64 QAM which is used in 4G communications. 

 

64 QAM uses six bits of data at a time, thus making the data transfer speed six times faster compared to a normal modulation technique. 

 

The modulation techniques are not restricted to only cellular communication and FM radio, but also have applications in television broadcasting, Wi-Fi, optical fibers et cetera. We hope this article has given you a clear understanding about the concepts of modulation. Thank you.

How to Learn Faster

If you’d like to memorize 10 times faster,this video will show easily you can improve. 

 

You remember information in two main ways– as words, using your verbal memory, or as pictures, using your visual memory. 

 

They’re different mental processes and they achieve dramatically different results. People never believe how absolutely crazy the difference is, so here’s a challenge for you and you can prove it for yourself. 

 

First, let’s test your verbal memory. I’ll give you a list of ten words and let’s see how many you’re able to remember. Here we go: PianoElephant TruckBottle BasketballChair PineappleDog PaintingTrampoline Ok, pause the video and write down all the words you can remember. 

 

How’d you go? If you’re like the average person, you were able to recall about five to seven words, not necessarily in the right order. 

 

So that was your verbal memory, now let’s test your visual memory. I’ll give you another list of words, but this time, I’ll also give a short story and draw a picture. To activate your visual memory, just create a mental picture of everything I describe and draw. 

 

You can even close your eyes and just listen to my voice. Here we go. Ferrari – Imagine you’re driving a bright red Ferrari with the top down. 

 

The music is pumping above the throaty growl of the engine, and your hair is blowing in the wind. Chicken – With a loud ‘thump’ a giant chicken lands in the seat next to you. 

 

It’s the size of a person, enormous and yellow. It must have fallen out of the sky. Watermelon – The chicken opens the car door and leaps out onto the road. 

 

As it stands there, an enormous green watermelon rolls over the top of it and keeps rolling down the road. Barack Obama – 

 

You watch the watermelon roll down the road and straight into Barack Obama. The watermelon splits in half and Obama is left standing there, dripping in watermelon juice. 

 

Poodle – Obama picks up a passing poodle and uses it to wipe juice off his face. The poodle is pure white, but as it soaks up watermelon juice it slowly turns bright pink. 

 

Flagpole – Obama throws the poodle away,it flies through the air and lands on the top of a tall flagpole. The weight of the juicy poodle causes the flagpole to slowly topple over. 

 

Cake – With a loud and messy ‘splat’ the flagpole falls into the middle of an enormous birthday cake. Icing, cream and candles go flying everywhere,raining down on people passing by. 

 

Doll – A large dollop of cream lands on the head of an oversized Barbie doll. It creates a weird chemical reaction and the doll shoots into the sky like a space rocket, blonde hair trailing behind her. 

 

Pizza – The doll rockets upwards and justas it starts to fall, a large pizza explodes open above her head like a parachute. The pizza is attached to the doll by long strings of melted cheese. Giraffe – 

 

The pizza eventually lands on the ground, covering the doll, and a giraffe walks over and starts eating the pizza, benyding its long neck and stretching its tongue to lick up the delicious cheese. 

 

Skateboard – After eating too much pizza,the giraffe pulls out a skateboard, jumps on it, and starts gliding down the street,ducking signs and street lights as it rolls along. 

 

Cigarette – The skateboard begins coughing,and it stops and uses one of its wheels to light a cigarette. The cigarette becomes engulfed in flames and the skateboard throws it away. Statue of Liberty – 

 

The flaming cigarette flies through the air and lands on the torch being held aloft by the Statue of Liberty. The torch bursts into flames too. 

 

Ice cream – The Statue of Liberty comes alive and thrusts the burning torch deep into a big bucket of ice cream. It’s cherry chocolate ice cream that melts and starts to bubble ominously. 

 

Fireworks – The ice cream explodes into fireworks, lighting up the sky above the Statue of Liberty with brightly colored fireworks forming the words ‘The End’. Ok, pause the video again and write down how many words you’re able to recall using your visual memory. 

 

The trick is to re-create a picture in your mind of each image in the story. Did you see the difference? And I did something sneaky, I gave you fifteen words, not ten, but the average person would have been able to recall from ten up to all fifteen words, and mostly in the correct order. Leave a comment below and let me know how your verbal memory scored against your visual memory. 

 

Visual memory techniques have been around for thousands of years, but for some strange reason, most people only know verbal memory techniques. 

 

Verbal techniques are things like acronyms and acrostics, word associations and rhymes, and even songs, and they all need a serious chunk of boring repetition. They can be fantastic for a small number of words, but they don’t activate the amazing power of your visual memory.

What is field Effect Transistor

Effect Transistor:- In this article we will briefly learn about the field effect transistor.

 

The field effect transistor or FET is a three terminal device, which uses the electric field to control the flow of current through the device. 

 

And it is very useful in many applications. In fact today most of the integrated circuits including the computers are designed using this FETs.

 

So the three terminals of the FET are known as gate, drain and source. so inFET, the current used to flow between the drain and the source terminal. 

 

And this current can be controlled by applying the voltage between the gateand the source terminal. 

 

So these applied voltage generates the electric field within the device and by controlling this electric field or in a way by controlling this voltage we can control the flow of current through the device.so basically in this field effect transistor, by controlling the electric field we can control the flow of current. 

 

And that is why it is known as the field effect transistor. 

 

So this field effect transistor is the voltage control device that means the input voltage between the gate and the source terminal controls the output current. 

 

On the other end if you look at the BJT or the BipolarJunction Transistor, it is a current controlled device, where the input basen current controls the output collector current.

 

So this is the one of the differences but in the field effect transistor and the bipolar Junction transistor.

 

The second difference is the FET is a unipolar device, while the BJT is bipolar device. Meaning that the BJT relies on the two types of charges, the free electron and the holes. 

 

But the operation of the FET relies on either holes or electron. 

 

Now in terms of the application, the FETs are used in almost all the applications where the BJTs are used. For example they are used as a amplifier or oscillator in many applications and apart from that also used as analog switch in many applications. 

 

But the biggest difference between the field effect transistor and the BJT is that the input impedance of the field effect transistor is very high and due to that they are used as a buffer amplifier in many applications.

 

Apart from that the FETs are smaller in size compared to the BJTs. And that’s why they are commonly used in the integrated circuits. 

 

Apart from that now if we talk in terms of the power consumption the power consumption of the FET is less than BJT.

 

And that’s why they are preferred in many high power applications as well as in the computing applications, particularly where the required power consumption should be minimum. 

 

So these are the few differences between the FETand the BJT. 

 

Now let us see the different types of FETs. So basically there are two types of FETs.  The first is the junction field effect transistor or the JFET. 

 

And the second type is IG-FET. or it is known as the insulated gate field effect transistor. And the MOSFET is the most common type of IG-FET. 

 

So let us briefly discuss about these two types of FETs. Now as I said earlier the FET has three terminals. The gate source and the drain. 

 

And the current flows between the drain and the source terminals. Now in this field effect transistor the path through which these charge carrier flows is known as the channel and if this channel is made up of n-type semiconductor then the field effect transistor is known as the n-channel FET.  Likewise, if the channel is made up of p-type material then it is known as the p-channel FET. 

 

And in this FET, the gate terminal is placed very close to this channel, so that it can control the flow of current through this channel. 

 

Now in this JFET this gate terminal is provided using this PN Junction. 

 

So if you see the n-type JFET,two small p-type regions are fabricated near this channel. And due to that the PN Junction is formed near this channel and whenever this PN Junction is reversed bias then the depletion region of this PN Junction isolates the gate terminal from the channel. 

 

And only a small amount of reverse saturation current used to flow between these two regions. So in a way this reverse bias PNJunction isolates the gate terminal from the channel and that is why this type of field effect transistor is known as the JFET or the junction field effect transistor.

 

 Now as I said earlier if this channel is made up of n-type semiconductor then it is known as the n-channel JFET. And likewise if it is made up of p-type semiconductor then the JFET is known as the p-channel JFET.

 

So in this way there are two types of JFET. The n-channel and p-channel JFET.so now let us talk about the second type of FET. So this IG-FET uses an insulated layer between the gate terminal and the channel. 

 

And typically this insulated layer is formed from the oxide layer of the semiconductor.now here the name IG-FET refers to the any type of FET which has an insulated gate. 

 

And the most common form of IG-FET is the MOSFET.So in this MOSFET, the gate is made up of a metal layer and the insulating layer is made up of silicon dioxide. now this MOSFET can be further classified into two types. 

 

The depletion type and the enhancement type. So let us underst and briefly about these two types.

 

Now when we apply the voltage at the gate terminal then due to the electric field it can either deplete or enhance a number of charge carriers in this given channel. So by the application of the voltage if the number of charge carriers gets depleted in this channel then it is known as the depletion type of FET. 

 

And if the number of charge carrier increases then it is known as the enhancement type of FET.

 

So this structure which is shown in this diagram is the depletion type of MOSFETwhere the applied voltage at the gate terminal depletes the charge carriers in this n channel. While this structure which is shown in the diagram is the enhancement type of MOSFET. 

 

So in this type of MOSFET the channel is formed between these two n- regions whenever we apply the voltage at the gate terminal.So these are the two types of MOSFETs. and these two types of MOSFETs can be further classified either as n-channel or p-channel MOSFETs. so these are the basic types of a FETs. 

 

And of course there are other types of FETs likeFin-FET and the CMOS, but we will talk about it in the separate article. so from the next Article onwards we will see the working of this JFET and the MOSFET. And we will also see the symbol as well as a transfer characteristic of this different types of FETs. And once we finish that then we will see that how tobias this FETs.