computer teacher

 Smart Cities With rapid urbanization, the load on our cities are increasing day-by-day, and there are challenges in management of resources like land water, waste, air pollution, health and sanitation, traffic congestions, public safety and security, besides the overall city infrastructures including road, rail, bridge, electricity, subways, disaster management, sports facilities, etc.  These challenges are forcing many city planners around the world to look for smarter ways to manage them and make cities sustainable and livable. The idea of a smart city as shown in Figure 3.11 makes use of computer and communication technology along with IoT to manage and distribute resources efficiently.   The smart building shown here uses sensors to detect earthquake tremors and then warn nearby buildings so that they can prepare themselves accordingly.  The smart bridge uses wireless sensors to detect any loose bolt, cable or crack. It alerts concerned...

 Cloud Services A better way to understand the cloud is to interpret everything as a service. A “service” corresponds to any facility provided by the cloud.  There are three standard models to categorize different computing services delivered through cloud as shown in Figure 3.12.  These are Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). Infrastructure as a Service (IaaS) The IaaS providers can offer different kinds of computing infrastructure, such as servers, virtual machines (VM), storage and backup facility, network components, operating systems or any other hardware or software.  Using IaaS from the cloud, a user can use the hardware infrastructure located at a remote location to configure, deploy and execute any software application on that cloud infrastructure.  They can outsource the hardware and software on a demand basis and pay as per the usage, thereby they can save the cost o...

 Grid Computing A grid is a computer network of geographically dispersed and heterogeneous computational resources as shown in Figure 3.13.  Unlike cloud, whose primary focus is to provide services, a grid is more application specific and creates a sense of a virtual supercomputer with an enormous processing power and storage.  The constituent resources are called nodes.  These different nodes temporarily come together to solve a single large task and to reach a common goal. Nowadays, countless computational nodes ranging from hand-held mobile devices to personal computers and workstations are connected to LAN or Internet. Therefore, it is economically feasible to reuse or utilise their resources like memory as well as processing power.   The grid provides an opportunity to solve computationally intense scientific and research problems without actually procuring a costly hardware. Grid can be of two types— (i) Data grid, used to manage larg...

 Blockchain technology  Traditionally, we perform digital transactions by storing data in a centralized database and the transactions performed are updated one by one on the database. That is how the ticket booking websites or banks operate. However, since all the data are stored on a central location, there are chances of data being hacked or lost. The blockchain technology works on the concept of decentralized and shared database where each computer has a copy of the database.  A block can be thought as a secured chunk of data or valid transaction. Each block has some data called its header, which is visible to every other node, while only the owner has access to the private data of the block. Such blocks form a chain called blockchain as shown in Figure 3.14. We can define blockchain as a system that allows a group of connected computers to maintain a single updated and secure ledger. Each computer or node that participates in the blockchain receives...