Face Recognition Technology

Wouldn’t you love to replace password based access control to avoid having to reset forgotten password and worry about the integrity of your system? Wouldn’t you like to rest secure in comfort that your healthcare system does not merely on your social security number as proof of your identity for granting access to your medical records?
Because each of these questions is becoming more and more important, access to a reliable personal identification is becoming increasingly essential. Conventional method of identification based on possession of ID cards or exclusive knowledge like a social security number or a password are not all together reliable. ID cards can be lost forged or misplaced; passwords can be forgotten or compromised. But a face is undeniably connected to its owner. It cannot be borrowed stolen or easily forged.
The information age is quickly revolutionising the way transactions are completed. Everyday actions are increasingly being handled electronically, instead of with pencil and paper or face to face. This growth in electronic transactions has resulted in a greater demand for fast and accurate user identification and authentication. Access codes for buildings, banks accounts and computer systems often use PIN's for identification and security clearances.
Using the proper PIN gains access, but the user of the PIN is not verified. When credit and ATM cards are lost or stolen, an unauthorized user can often come up with the correct personal codes. Despite warning, many people continue to choose easily guessed PIN's and passwords: birthdays, phone numbers and social security numbers. Recent cases of identity theft have hightened the nee for methods to prove that someone is truly who he/she claims to be.
Face recognition technology may solve this problem since a face is undeniably connected to its owner expect in the case of identical twins. Its nontransferable. The system can then compare scans to records stored in a central or local database or even on a smart card.

The Face :

The face is an important part of who you are and how people identify you. Except in the case of identical twins, the face is arguably a person's most unique physical characteristics. While humans have the innate ability to recognize and distinguish different faces for millions of years , computers are just now catching up.

Face recognition technology analyze the unique shape ,pattern and positioning of the facial features. Face recognition is very complex technology and is largely software based. This Biometric Methodology establishes the analysis framework with tailored algorithms for each type of biometric device. Face recognition starts with a picture, attempting to find a person in the image. This can be accomplished using several methods including movement, skin tones, or blurred human shapes. The face recognition system locates the head and finally the eyes of the individual. A matrix is then developed based on the characteristics of the individual’s face. The method of defining the matrix varies according to the algorithm (the mathematical process used by the computer to perform the comparison). This matrix is then compared to matrices that are in a database and a similarity score is generated for each comparison.

Electronics : Silicon Memory

Abstract

The limits of pushing storage density to the atomic scale are explored with a memory that stores a bit by the presence or absence of one silicon atom. These atoms are positioned at lattice sites along self-assembled tracks with a pitch of five atom rows.

The memory can be initialized and reformatted by controlled deposition of silicon. The writing process involves the transfer of Si atoms to the tip of a scanning tunneling microscope. The constraints on speed and reliability are compared with data storage in magnetic hard disks and DNA.
In 1959 physics icon Richard Feynman estimated that “all of the information that man has carefully accumulated in all the books in the world, can be written in a cube of material one two-hundredth of an inch wide”. Thereby, he uses a cube of 5×5×5 = 125 atoms to store one bit, which is comparable to the 32 atoms that store one bit in DNA. Such a simple, back-of-the-envelope calculation gave a first glimpse into how much room there is for improving the density of stored data when going down to the atomic level.
In the meantime, there has been great progress towards miniaturizing electronic devices all the way down to single molecules or nanotubes as active elements. Memory structures have been devised that consist of crossed arrays of nanowires linked by switchable organic molecules or crossed arrays of carbon nanotubes with electro statically switchable intersections

Introduction

Now, a little more than 40 years after Feynman's prescient estimate, scientists have created an atomic-scale memory using atoms of silicon in place of the 1s and 0s that computers use to store data. The feat represents a first crude step toward a practical atomic-scale memory where atoms would represent the bits of information that make up the words, pictures and codes read by computers.
It is our goal to push the storage density to the atomic limit and to test whether a single atom can be used to store a bit at room temperature. How closely can the bits be packed without interacting? What are the drawbacks of pushing the density to its limit while neglecting speed, reliability and ease of use?
The result is a two-dimensional realization of the device envisaged by Feynman, as shown in figure 1. A bit is encoded by the presence or absence of a Si atom inside a unit cell of 5×4 = 20 atoms. The remaining 19 atoms are required to prevent adjacent bits from interacting with each other, which is verified by measuring the autocorrelation. A specialty of the structure in figure 1 is the array of self-assembled tracks with a pitch of five atom rows that supports the extra atoms. Such regular tracks are reminiscent of a conventional CDROM. However, the scale is shrunk from µm to nm. Although the memory created now is in two dimensions rather than the three-dimensional cube envisioned by Feynman, it provides a storage density a million times greater than a CD-ROM, today's conventional means of storing data

Conventional Storage Media

We are going to discuss about atomic scale memory at a silicon surface .But some knowledge about the conventional storage media will help us to understand the atomic scale memory deeply.

The highest commercial storage density is achieved with magnetic hard disks, whose aerial density has increased by seven orders of magnitude since their invention in Feynman's days. Currently, the storage density is approaching 100 Gigabits per square inch in commercial hard disks. Typical storage media consist of a combination of several metals, which segregate into magnetic particles embedded into a non-magnetic matrix that keeps them magnetically independent. A strip of particles with parallel magnetic orientation makes up a bit, as color coded red and turquoise in the figure below. (The dimensions keep getting smaller.) When such a bit is imaged by a magnetic force microscope the collection of these particles shows up as white or dark line, depending on the magnetic orientation

The density limit in magnetic data storage is largely determined by the in homogeneity of the magnetic particles that make up the storage medium. Overcoming variations in particle size, shape, spacing, and magnetic switching currently requires the use of about 100 particles per bit. The error limits are extremely stringent (less than one error in 108 read/write cycles, which can be reduced further to one error in 1012 cycles by error-correcting codes). The individual particles in today's media approach the super paramagnetic limit already (about 10 nm), where thermal fluctuations flip the magnetization.
For further improvements one has to use fewer, but more homogeneous particles. These can be synthesized with great perfection by growing them with a protective surfactant shell. Our current research is aimed at depositing an ordered array of such nano particles onto structured silicon surfaces. The ultimate goal is a single particle per bit memory, which would increase the storage density by a factor of 100

The new memory was made without the use of lithography as required to make conventional memory chips. To make conventional memory chips, light is used to etch patterns on a chemically treated silicon surface. To use lithography to make chips that are denser than the best available chips is prohibitively expensive and difficult.
The self-assembled memory structure shown in figures 1 and 2 is obtained by depositing 0.4 monolayer of gold onto a Si(111) surface at 700 ◦C with a post-anneal at 850 ◦C, thereby forming the well-known Si(111)5 × 2–Au structure. All images are taken by STM with a tunneling current of 0.2 nA and a sample bias of −2 V. At this bias the extra silicon atoms are enhanced compared to the underlying 5 × 2 lattice. A stepped Si(111) substrate tilted by 1◦___ towards the azimuth is used to obtain one of the three possible domain orientations exclusively.
The surface arranges itself into tracks that are exactly five atom rows wide (figure 1). They are oriented parallel to the steps. Protrusions reside on top of the tracks on a 5 × 4 lattice. Only half of the possible sites are occupied in thermal equilibrium (figure 4(a)).When varying the Au coverage the occupancy remains close to 50%. Excess Au is taken up by patches of the Au-rich Si(111)√3 × √3–Au phase, and Au deficiency leads to patches of clean Si(111)7 × 7. In order to find out whether the protrusions are Si or Au, we evaporate additional Si and Au at low temperature (300 ◦C). Silicon fills the vacant sites (figures 4(b) and (d)), but gold does not.
In figure 4(b) the occupancy of the 5 × 4 sites has increased to 90±3% from 53±4% in figure 4(a). Higher annealing allows the extra Si to diffuse away to the nearest step and causes vacancies to reappear, confirming that the half-filled structure is thermodynamically stable. Thus, an average code with 1 and 0 in equal proportion is particularly stable.

Writing is more difficult. While atoms can be positioned controllably at liquid helium temperature, that is much harder to achieve that at room temperature. In order to prevent them from moving around spontaneously it is necessary to choose atoms that are strongly bound to the surface. Pushing them around with the STM tip requires a close approach, which entails the risk of an atom jumping over to the tip. This problem can be turned into a solution by using the STM tip to remove silicon atoms for writing zeros. The memory is pre-formatted with a 1 everywhere by controlled deposition of silicon onto all vacant sites Advantages and Disadvantages
An intriguing aspect of atomic scale memory is that memory density is comparable to the way nature stores data in DNA molecules. The Wisconsin atomic-scale silicon memory uses 20 atoms to store one bit of information, including the space around the single atom bits. DNA uses 32 atoms to store information in one half of the chemical base pair that is the fundamental unit that makes up genetic information. Compared to conventional storage media, both DNA and the silicon surface excel by their storage density. Obviously there are some drawbacks. The memory was constructed and manipulated in a vacuum, and that a scanning tunneling microscope is needed to write memory which makes the writing process very time consuming.
Moreover, there is a tradeoff between memory density and speed. As density increases, the ability to read the memory comes down because we get less and less of a signal. As we make things smaller, it's going to get slower

Conclusion and Future Scope

The push towards the atomic density limit requires a sacrifice in speed. Practical data storage might evolve in a similar direction, with the gain in speed slows down as the density increases. Somewhere on the way to the atomic scale ought to be an optimum combination of density and speed. If the reading and writing speed is improved and the memory is made cost effective, this will revolutionize the field of secondary storage devices. Researchers are working on manufacturing STM with multiple tips or heads that can perform parallel read-write processes.
This type of memory may eventually become useful for storing vast amounts of data, but because the stability of each bit of information depends on one or a few atoms, it likely to be used for applications where a small number of errors can be tolerated

Electronics : Brain Gate

Abstract

BrainGate is a brain implant system developed by the bio-tech company Cyberkinetics in 2003 in conjunction with the Department of Neuroscience at Brown University. The device was designed to help those who have lost control of their limbs, or other bodily functions, such as patients with amyotrophic lateral sclerosis (ALS) or spinal cord injury.

The computer chip, which is implanted into the brain , monitors brain activity in the patient and converts the intention of the user into computer commands. Cyberkinetics describes that "such applications may include novel communications interfaces for motor impaired patients, as well as the monitoring and treatment of certain diseases which manifest themselves in patterns of brain activity, such as epilepsy and depression."
Currently the chip uses 100 hair-thin electrodes that sense the electro-magnetic signature of neurons firing in specific areas of the brain, for example, the area that controls arm movement. The activities are translated into electrically charged signals and are then sent and decoded using a program, which can move either a robotic arm or a computer cursor. According to the Cyberkinetics' website, three patients have been implanted with the BrainGate system. The company has confirmed that one patient ( Matt Nagle ) has a spinal cord injury, while another has advanced ALS.

Brain Gate Neural Interface System

The Brain Gate Neural Interface System is currently the subject of a pilot clinical trial being conducted under an Investigational Device Exemption (IDE) from the FDA. The system is designed to restore functionality for a limited, immobile group of severely motor-impaired individuals. It is expected that people using the BrainGate System will employ a personal computer as the gateway to a range of self-directed activities. These activities may extend beyond typical computer functions (e.g., communication) to include the control of objects in the environment such as a telephone, a television and lights.

The BrainGate System is based on Cyberkinetics' platform technology to sense, transmit, analyze and apply the language of neurons. The System consists of a sensor that is implanted on the motor cortex of the brain and a device that analyzes brain signals. The principle of operation behind the BrainGate System is that with intact brain function, brain signals are generated even though they are not sent to the arms, hands and legs. The signals are interpreted and translated into cursor movements, offering the user an alternate "BrainGate pathway" to control a computer with thought, just as individuals who have the ability to move their hands use a mouse.

IBM, in partnership with scientists at Switzerland's Ecole Polytechnique Federale de Lausanne's (EPFL) Brain and Mind Institute will begin simulating the brain's biological systems and output the data as a working 3-dimensional model that will recreate the high-speed electro-chemical interactions that take place within the brain's interior
These include cognitive functions such as language, learning, perception and memory in addition to brain malfunction such as psychiatric disorders like depression and autism. From there, the modeling will expand to other regions of the brain and, if successful, shed light on the relationships between genetic, molecular and cognitive functions of the brain