Quantum Computing 

Postulates and Formalism of Quantum Mechanics -II

Postulate 1 : Wave function / State function In 1 dimensional system like Hydrogen atom  is time independent wave function   is time dependent wave function In 3 dimensional system like helium atom   is time independent wave function is time dependent wave function Inside the atoms electron structure / 2 particle electron system of 3D […]

Quantum Computers

We know that quantum computers can solve problems of greater complexity in much less time and computational power as classical computers , and by the virtue of this innovation we stand on the edge of a breakthrough. Quantum computers provide an unprecedented advantage in simulation and mission-critical problem solving . Conceptualisation : Quantum mechanics date […]

Compton scattering

Compton scattering is scattering of a photon by a charged particle (usually an electron). Compton effect is decrease in energy (increase in wavelength) of the photon after scattering. It was discovered by Arthur Holly Compton, It is an example of inelastic scattering of light by a free charged particle, where the wavelength of the scattered […]

Photoeletric effect -Wave Particle Duality

Photoelectric effect is emission of electrons from surface of solid by light . The solid material is said to be photoemissive and ejected electrons are called photoelectrons. In 1887 observed by German physicist Heinrich Hertz during his experiment with spark gap generator(radio) as he noticed that adding ultraviolet light increases the sensitivity of the metal […]

Quantum Tunnelling and Moore’s Law on Transistors

Transistors are electronic switches in IC’s which drive all the electronics today and are fundamental to growth in tech and computing. They are nearing the end of Moore’s Law ( with states doubling transistor count and reducing gate size every 2 years ) . We are now almost at a stage of having quantum or […]

Quantum Mechanics-I

While classical physics deals with Macroscopic scales , Quantum mechanics applied to microscopic scales which are largely affected by wave-particle duality and uncertainty principle.  For such microscopic particles ( atomic and subatomic  electrons, protons, neutrons, quarks and gluons.  ) the energy, momentum, angular momentum, and other quantities of a bound system are restricted to discrete […]

  • Particle in a Box
    • Method of Separation of Variables and Particle in a 2 & 3 dimensional space
    • Time Dependant QM function
    • Particle in a well of Finite depth
  • Harmonic Oscillator Problem
  • Hydrogen Atom Problem
  • Time independent and Time dependant Perturbation theory
  • Variational Method
  • Algorithms in Quantum computing-II

Computer vision

CNN Computer vision

Deep Neural Network for Object Detection Convolution Neural Networks (CNN) LeNet (1989) LeNet-5 Alexnet GoogLeNet  / v1 Inception ResNet Object Classifcation Localization YOLO Transfer Learning Image Captioning This article explains popular CNN Architectures specific to object recognition. If you are new you should go through Computer vision basics first. Deep Neural Network for Object Detection […]

Computer vision basics

Computer vision has roots in cognitive sceince . Inside computer vision are many subjects like : object detection, image captioning, semantic segmentation, visual question answering, visual instruction navigation, scene graph generation. Feature Extractors Dimensionality reduction by which an initial set of raw data is reduced to more manageable groups for processing. Used in Machine learning […]

Computer Vision for Garbage Detection in Real-Time Video Stream

Garbage detection and classification is a critical need of hour to not only provide clean enviornment but also to help in recycling . The area of automatic garbage detection has far reaching impacts for socital welbeing and saving the environment. To detect grabge , litter , trash from a realtiem video stream is an ardous […]



Biometrics is the science of measuring an individual’s physiological or behavioral characteristics for automatic identification. Biometrics is the only viable approach to personal recognition. It can give automatic personal recognition based on physiological or behavioral Characteristics. Any human biometric character satisfies A) Universality B) Distinctiveness C) Permanence D) Collectiveness. Biometry offers greater security and convenience […]


Robotic Arm with 6 degree of Freedom

This document describes technicals of robotic arm for 6 degrees of freedom (DOF) using shared control structure. This control structure should also have semiautonomous sensor-based actions. Aim: Aim is to establish simple actions such as gripping an object in an unstructured environment or pouring a cup with a water. Out of Scope of this study: locating objects or planning a […]

Computer Science


Secure Channel Symmetric Encryption Authentication using public-key cryptography Digital Signature Access-control Access control Matrix Firewalls Security Management CA Public key certificates diffie-hellman-key-exchange Secure Channels Symmetric keys Asymmetric keys Algorithm same key for encryption and decryption public key for encryption and private key for decryption Security and sharing shared key should be secret between the two […]

Graph theory and Algorithms

Lets discuss Trees which represent structural relationship in data and are used to represent hierarchies . Tree node struct TreeNode { Object element ; TreeNode * firstChild ; TreeNode * nextSibling ; }; Tree height – (longest root-to-leaf path int height(Tree root) { if (root == null) return 0; else { return 1 + Math.max(height(root.left),height(root.right)); […]

Programming language Idioms

A programmer should acquire good algorithms and idioms.  Alan J. Perlis – SICP Foreword So what is an programming idiom ?  An Idiom is a low-level pattern specific to a programming language. It describes how to implement particular aspects of the components or the relationships between them using the features of a given language. In my opinion it […]

TLS ( Transport Layer Security)

TLS provides a secure channel between two communicating peers; the only requirement from the underlying transport is a reliable, in-order data stream. It has roots in SSL (Secure socket Layer ) and is used by popular application layer protocols like HTTP, FTpP SMTP, XMPP, SIP over TLS, DTLS etc. Historically TLS has been used with […]

Semaphores and Mutex

Proposed by Dijkstra in 1965 for concurrent process management . A non negative variable used by threads for process synchronisation . In a multi process environment serval threads may be concurrently accessing a shared resource. This could lead to Race condition or data inconsistency. Semaphores follow mutual exclusion principle and solve the critical section problem […]


An operator is a symbol that tells the compiler or interpreter to perform specific mathematical, relational or logical operation. Arithmetic + Adds – Subtracts * Multiplies / Divides % Modular / Remainder Relational == equals != not equal > greater than < less than >= greater than or equal to <= less than or equal […]

Operating systems

What is an Operating System? A program that acts as an intermediary between a user of a computer and the computer hardware. Roles of OS  Program execution – system capability to load a program into memory and to run it. I/O operations – since user programs cannot execute I/O operations directly, the operating system must […]

Computer organization and Architecture

Topics covered OS and schedulling Machine Instruction Addressing Modes ALU Data Path Control Unit Instruction pipelining Memory hierarchycache , main memory , secondary storage IO interface  interrupt, DMA model first documented computer architecture was in the correspondence between Charles Babbage and Ada Lovelace, describing the analytical engine. Further paper describing stored instruction John von Neumann‘s […]

Problems and Algorithms

A process or set of rules to be followed in calculations or other problem-solving operations, especially by a computer. – Definitions from Oxford Languages Some of the catagories of algorithms and theor description are below Brute Force Recurssive Divid And Conquer Greedy Route Finding MST APSP SSSP Heuristic Backtracking Primarity Test Integer Factorization Sequenxe Sorts […]

Software engineering

Design Patterns in Java

Summary of popular Design pattern and Architectural design in Java projects. The exmaples are derived form a Java Soring project managing internation addresses. The link to the project is at the end of this article under references . IOC ( Inversion of Control )  The container injects the dependencies when it creates the bean Spring […]

Architetural Styles and Architetural Patterns

An architectural style is how the code is organized from a abstracted viewpoint while and architectural pattern is solution can be used to solve a reoccurring problem. A design pattern on the other hand is the accumulated best practices and idomatic code that proficient software professional use over the years of experience to write high […]

Design Patterns

Article references Gangs of four on Creational , structural and behavioural design partterns with diagrams , samples , pros /cons and uses . Bonus interview or exam questions on design pattern in software architecture and engineering

Btech Information Technology (Anna University) – Syllabus and Curriculum 2007-2011

Description and details of  bachelors of technology degree in Information Technology course from Anna university in term 2007 -2011  Content include Data structures Software Engineering DBMS OOPS Operating Systems , distributed systems and embedded system Networks Maths Digital signal processing and Telecommunication Microprocessor and microcontroller Data Structures CS1151 Data structures  Marks 61/100 UNIT I  PROBLEM […]

Language Theory

Types of Languages : Regular DCFL ( Deterministic context free language) CFL ( context Free Language) IND ( Indexed Language) CSL ( Context Sensitive Language) Recursive RE ( Recursively enumerable language) Regular and Non Regular Languages Regular languages are defined recursively over an alphabet A as follows: The empty set \null is regular. The set […]

Working with GIT

Git is a distributed version control system that is used for software development. Its strength are in ease of managing non-linear workflows. There are 4 major steps for git to function . 1.Make a project and add the repo link git remote add origin <remote repository URL> 2. Identify and add the files . git add […]

Search Engine Optimization (SEO)

Quite simply put , if the search engines do not list your site on the top page of results ton user search, chances of users landing on your website are pretty dim . It is, for this reason, that website owners try to incorporate small incremental changes which individually dont amount to much but together […]

Processes and Schedulars

Process It has 4 sections, text : compiled program code, read in from non-volatile storage when the program is launched. data : global and static variables, allocated and initialized prior to executing the main. heap : used for dynamic memory allocation, and is managed via calls to new, delete, malloc, free, etc. stack : used […]

Statistics, DataScience and Machine Learning

Statistical Sciences – brief list of subjects

This artcile is not descriptive , rather a list of subjects and topics and are often part of statistics . An outline of the topics mentione dbelow are Probability and Advance Probability Statistics and Probability , Applied Probability and Statistics Statistics for Data Science – Machine Learning , Applied Regression and Analysis of Variance , […]

Probabilistic programming

Derivatives and differential equations  

If y=f(x) is the function than y ‘ is the slope , defined as rate of change of y with respect to x. We know that equation for line is y = mx +c,  where m is the slope. m = y / x Therefore is there is a function that maps has two coordinates […]



JVM ( Java Virtual Machine)

Java is a high level, object-oriented all-purpose programming language. Read part 1 of this article Java introduction: https://programmingaltanai.wordpress.com/2014/07/22/java-intro/ To read about Java key concepts used in Java which define its usage and design such as Data structures, access modifiers, keywords – https://programmingaltanai.wordpress.com/2014/07/23/key-concepts/ The .class files generated by the compiler are not executable binaries but just contain bytecode […]

Java – Key concepts

Java is a high level, object-oriented all-purpose programming language. Read part 1 of this article Java introduction: https://programmingaltanai.wordpress.com/2014/07/22/java-intro/ This article describes key concepts used in Java which define its usage and design such as Data structures, access modifiers, keywords etc Overloading  Overloading is the ability to define more than one method with the same name in […]

Java – introduction

Java is a programming language originally developed by James Gosling Gosling at Sun Microsystems. It was acquired by the Oracle Corporation later. Top features : object-oriented, follow OOPS concepts like abstraction, encapsulation, inheritance, object-oriented, and polymorphism Multithreading support vast library of predefined objects and operations Just-In_Time Compiler (JIT) to convert bytecode into executables platform-independent thanks […]


Npm to github packages

Since npm is now merged with github ( + Microsoft ) , the npm package publishing process got broken somewhere i was facing errors on both npm install npm ERR! code E404 npm ERR! 404 Not Found – GET https://npm.pkg.github.com/after npm ERR! 404 npm ERR! 404 ‘after@0.8.2’ is not in the npm registry. npm ERR! […]


Nodejs lets you write web apps that use Javascript on both the server and the client, so you don’t need to know multiple programming languages to program your website. It’s also really good at handling real-time concurrent web applications, which makes it a great choice for a lot of modern web apps. Technically : Node.js […]

Java EE

Difference between MVC , Struts and Spring

MVC MVC stands for Model View and Controller. It is a design pattern that separates the business logic, presentation logic and data. Model : represents the state of the application i.e. data. It can also have business logic. bean classes or POJO , compromising of variables declarations , getters and setters, DAO operations View : […]

MVC Jsp Servlet CRUD project

The aim of this tutorial is to outline the steps of developing a CRUD (Create Read Update Delete) User Management Web Application . We would primarily be using Jsp, Servlet and MySQL for this purpose . The front-end will also contain JSTL tags and Jquery .  REQUIREMENTS : 1. Eclipse IDE for Java EE Developers Download […]

Threads and Multithreading in Java

Multiple contexts/program counters running within the same memory space . All objects can be shared among threads . Fundamentally nondeterministic Two ways to create a new thread of execution declare a class to be a subclass of Thread override the “run” method of class Thread instance of the subclass can then be allocated and started […]


Python programming

Python is cross platform , general-purpose interpreted, high-level programming language. Python source code is also available under the GNU General Public License (GPL). Read More : https://www.python.org/ Multi-Paradigm Python supports multiple programming paradigms, including object-oriented, imperative and functional programming or procedural styles. It features a dynamic type system and automatic memory management and has a […]


PHP: Hypertext Preprocessor

PHP is a server-side scripting language designed for web development but also used as a general-purpose programming language. Originally created by Rasmus Lerdorf in 1994 Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world. Read More : http://php.net/ Types Boolean : TRUE or FALSE , case […]

Digital Logic