Tuesday 21 June 2016

Arduino Yun

Overview;
The Arduino Yun is a microcontroller board based on the ATmega32u4 and the Atheros AR9331. The Atheros processor supports a Linux distribution based on OpenWrt named OpenWrt-Yun. The board has built-in Ethernet and WiFi support, a USB-A port, micro-SD card slot, 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator, a micro USB connection, an ICSP header, and a 3 reset buttons.

Technical Specifications:

Microcontroller ATmegs32U4
Operating Voltage 5V
Input Voltage 5v
Digital I/O Pins 20
Pwm Channel 7
Analog Input Pins 12
Flash Memory 32 KB
SRAM 2.5 KB
EEPROM 1 KB
Clock Speed 16 MHz

OpenWrt-Yun

The Yun runs a distribution of Linux called OpenWrt-Yun, based on OpenWrt. While it's possible to configure the system from the command line, there is a web page that allows you to configure many of the different options available. The interface (called LuCi) gives you access to most any setting you would need for maintaining the WiFi interface.

Accessing the web interface is described below.

To install additional software on OpenWrt-Yun, you need to use the the Linux package manager opkg. 

When interfacing with the OpenWrt-Yun system, you have to use a command line, either accessing it through the Arduino's Bridge library, or via SSH. If you are unfamiliar with the command line, you may want to read about some basics about it and some of the programs that are frequently used.

Python

An installation of Python 2.7 is included with OpenWrt-Yun, with which you can write applications or scripts.

External storage on the Yún

You can use external memory like a microSD card or thumb drive for saving data, or your own scripts, web pages, etc. For the Yún to access and store information on these drives through the 32U4, they need to have a directory named arduino in the root of the volume.

For additional information and documentation, refer 

Friday 11 December 2015

Google's Quantum Computer

Nowdays,Google is testing a quantum computer—a machine based on the seemingly magical principles of quantum mechanics, the physics of things like atoms and electrons and photons. This computer, called the D-Wave, carries a $10 million price tag, and the idea is that it can perform certain tasks exponentially faster than computers built according to the laws of classical physics—the physics of the everyday world.

In the future, says Hartmut Neven, who oversees Google’s experiments with the D-Wave, it may significantly improve machine learning, the technique by which computers analyze vast troves of data to learn skills like recognizing photos, identifying spoken words, understanding natural language, and, maybe one day, mimicking common sense.

Neven—who helped write the Google research paper, released earlier this week, that details the company’s experiments—compares the D-Wave to the airplane the Wright brothers flew at Kitty Hawk in 1903. The Wright Flyer barely got off the ground, but it foretold a revolution. “Their airplane took a trajectory through the air,” he says. “That’s the point”

In the same way, he says, the D-Wave has solved problems following a flight path that defies the laws of classical physics. “In fact, the trajectory went through parallel universes to get to the solution,” he says. “It is literally that. That is an amazing, somewhat historical, event. It has worked in principle. The thing flew.”

The tech company says its mammoth D-Wave 2X quantum computing machine has been figuring out algorithms at 100,000,000 times the speed that a traditional computer chip can, and that could make a huge difference in the processing power at our disposal in the future.

n quantum computing (closely linked to quantum mechanics), quantum bits (or 'qubits') can simultaneously hold values of 1, 0, or both, rather than being set to 1 or 0 as traditional electronic bits are. The qubits are tiny particles suspended in temperatures just above absolute zero, and as more qubits are added, the available processing power goes up exponentially. Big data problems, such as weather forecasts or chemical analysis, could be dealt with much faster through the power of quantum computing.

Friday 2 October 2015

NS3 Installation


Steps For NS3 Installation In Fedora 20:




1) Yum update



2)Update libraries



yum install gcc gcc-c++ python python-devel mercurial bzr gsl gsl-devel gtk2 gtk2-devel gdb valgrind doxygen graphviz ImageMagick python-sphinx dia texlive texlive-latex flex bison sqlite sqlite-devel libxml2 libxml2-devel uncrustify openmpi-devel gnuplot

yum install graphviz graphviz-devel python-setuptools-devel python-kiwi pygoocanvas pygraphviz


copy it in one sh file and rn that sh file. Eg ns_install.sh



3)Download tar file of latest NS3 release from www.nsnam.org and unzip it.



4) cd ns-allinone-3.23 and run command



                ./build.py --enable-examples --enable-test .



5)cd ns-3.23 and run command

             
                ./test.py.



6) for running simple program copy program into scratch folder


              eg.  cp exaples/tutorials/first.cc scratch/sample.cc



(do not edit or run program in examples/tutorials directory, copy it and then run it )



7) for running c program(.cc) program , run commad

           
              ./waf --run filename.

              
               For eg ./waf --run sample



8) for running python program , run command 

               ./waf --pyrun filename.py.
9)for running animation
              
               cd netanim
              ./NetAnim

to read more go to www.nsnam.org


Monday 7 September 2015

802.15.4 – ZigBee


802.15.4 – ZigBee Physical Layer

ZigBee is a wireless technology developed as an open global standard to address the unique needs of low-cost, low-power wireless M2M networks. The ZigBee standard operates on the IEEE 802.15.4 physical radio specification and operates in unlicensed bands including 2.4 GHz, 900 MHz and 868 MHz.
The 802.15.4 specification upon which the ZigBee stack operates gained ratification by the Institute of Electrical and Electronics Engineers (IEEE) in 2003. The specification is a packet-based radio protocol intended for low-cost, battery-operated devices. The protocol allows devices to communicate in a variety of network topologies and can have battery life lasting several years.



The ZigBee Advantage

The ZigBee protocol is designed to communicate data through hostile RF environments that are common in commercial and industrial applications.
ZigBee protocol features include:

  • Support for multiple network topologies such as point-to-point,
    point-to-multipoint and mesh networks
  • Low duty cycle – provides long battery life
  • Low latency
  • Direct Sequence Spread Spectrum (DSSS)
  • Up to 65,000 nodes per network
  • 128-bit AES encryption for secure data connections
  • Collision avoidance, retries and acknowledgements.


Mesh Networks

A key component of the ZigBee protocol is the ability to support mesh networking. In a mesh network, nodes are interconnected with other nodes so that multiple pathways connect each node. Connections between nodes are dynamically updated and optimized through sophisticated, built-in mesh routing table.
Mesh networks are decentralized in nature; each node is capable of self-discovery on the network. Also, as nodes leave the network, the mesh topology allows the nodes to reconfigure routing paths based on the new network structure. The characteristics of mesh topology and ad-hoc routing provide greater stability in changing conditions or failure at single nodes.

ZigBee Applications

ZigBee enables broad-based deployment of wireless networks with low-cost, low-power solutions. It provides the ability to run for years on inexpensive batteries for a host of monitoring and control applications. Smart energy/smart grid, AMR (Automatic Meter Reading), lighting controls, building automation systems, tank monitoring, HVAC control, medical devices and fleet applications are just some of the many spaces where ZigBee technology is making significant advancements.
for more info-  http://www.digi.com/technology/rf-articles/wireless-zigbee










Monday 13 July 2015

A.M. Turing Award

Michael Stonebraker, Pioneer in Database Systems Architecture, Receives 2014 ACM Turing Award 

Michael Stonebracker is being recognized for fundamental contributions to the concepts and practices underlying modern database systems. Stonebraker is the inventor of many concepts that were crucial to making databases a reality and that are used in almost all modern database systems. His work on INGRES introduced the notion of query modification, used for integrity constraints and views. 

His later work on Postgres introduced the object-relational model, effectively merging databases with abstract data types while keeping the database separate from the programming language.

Stonebraker's implementations of INGRES and Postgres demonstrated how to engineer database systems that support these concepts; he released these systems as open software, which allowed their widespread adoption and their code bases have been incorporated into many modern database systems. 

Since the pathbreaking work on INGRES and Postgres, Stonebraker has continued to be a thought leader in the database community and has had a number of other influential ideas including implementation techniques for column stores and scientific databases and for supporting on-line transaction processing and stream processing.

For more info click here

Monday 6 July 2015

Can computers be creative?

World's first fictional ideation machine

The project acronym stands for the What-If Machine. It is also the name of the world's first fictional 'ideation' (creative process of generating, developing, and communicating new ideas) software, developed within the project. The software generates fictional mini-narratives or storylines, using natural language processing techniques and a database of facts mined from the web (as a repository of 'true' facts). The software then inverts or twists the facts to create 'what-ifs'. The result is often incongruous, 'What if there was a woman who woke up in an alley as a cat, but could still ride a bicycle?'

Can computers judge creativity?

WHIM is more than just an idea-generating machine. The software also seeks to assess the potential for use or quality of the ideas generated. Since the ideas generated are ultimately destined for human consumption, direct human input was asked for in crowd sourcing experiments. For example, WHIM researchers asked people whether they thought the 'what-ifs' were novel and had good narrative potential, and also asked them to leave general feedback. Through machine learning techniques, devised by researchers at the Jozef Stefan Institute in Ljubljana, the system gradually gains a more refined understanding of people's preferences.


Just the beginning

Generating fictional mini-narratives is just one aspect of the project. Researchers at the Universidad Complutense Madrid are expanding the mini-narratives into full narratives that could be more suitable for the complete plot of a film, for example. Meanwhile, researchers at the University College in Dublin are trying to teach computers to produce metaphorical insights and ironies by inverting and contrasting stereotypes harvested from the web, while researchers from the University of Cambridge are looking into web mining for ideation purposes. All of this work should lead to better and more complete fictional ideas.

More than a whim

While the fictional ideas generated may be whimsical, WHIM is based on solid science. It is part of the emerging field of computational creativity, a fascinating interdisciplinary discipline located at the intersection of artificial intelligence, cognitive psychology, philosophy, and the arts.

References:
 http://phys.org/news/2015-07-creative.html#jCp