ZigBee is a published specification set of high level communication protocols designed to use small, low-power digital radios based on the IEEE 802.15.4 standard for wireless personal area networks (WPANs). The relationship between IEEE 802.15.4-2003 and ZigBee is analogous to that existing between IEEE 802.11 and the Wi-Fi Alliance. The ZigBee 1.0 specifications were ratified on December 14, 2004 and are available to members of the ZigBee Alliance. An entry level membership in the ZigBee Alliance costs US$ 3500 and provides access to the specifications. For non-commercial purposes, the ZigBee specification is available to the general public at the ZigBee Alliance homepage.
The technology is designed to be simpler and cheaper than other WPANs such as Bluetooth. The most capable ZigBee node type is said to require only about 10% of the software of a typical Bluetooth or Wireless Internet node, while the simplest nodes are about 2%. However, actual code sizes are much higher, more like 50% of Bluetooth code size. ZigBee chip vendors announced 128-kilobyte devices.
As of 2005, the estimated cost of the radio for a ZigBee node is about $1.10 to the manufacturer in very high volumes. Most ZigBee solutions require an additional micro controller driving the price further up at this time. In comparison, before Bluetooth was launched (1998) it had a projected price, in high volumes, of $4-$6. The price of consumer-grade Bluetooth chips are now under $3.
ZigBee has started work on version 1.1. Version 1.1 is meant to take advantage of improvements in the 802.15.4b (still in draft) specification, most notably that of CCM* as an alternative to CCM(CTR + CBC-MAC)CCM mode. CCM* enjoys the same security proof as CCM and provides greater flexibility in the choice of Authentication and Encryption.
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Saturday, November 13, 2010
Blue Eyes
Is it possible to create a computer which can interact with us as we interact each other? For example imagine in a fine morning you walk on to your computer room and switch on your computer, and then it tells you “Hey friend, good morning you seem to be a bad mood today. And then it opens your mail box and shows you some of the mails and tries to cheer you. It seems to be a fiction, but it will be the life lead by “BLUE EYES” in the very near future.
The basic idea behind this technology is to give the computer the human power. We all have some perceptual abilities. That is we can understand each others feelings. For example we can understand ones emotional state by analyzing his facial expression. If we add these perceptual abilities of human to computers would enable computers to work together with human beings as intimate partners. The “BLUE EYES” technology aims at creating computational machines that have perceptual and sensory ability like those of human beings.
Mesotechnology
Mesotechnology describes a budding research field which could replace nanotechnology in the future as the primary means to control matter at length scales ranging from a cluster of atoms to microscopic elements. The prefix meso- comes from the Greek word mesos, meaning middle, hence the technology spans a range of length scales as opposed to nanotechnology which is concerned only with the smallest atomic scales.
describes very well phenomena on the atomic to nanoscale while classical Newtonian Mechanics describes the behavior of objects on the microscale and up. However, the length scale in the middle ( Although the term itself is still quite new, the general concept is not. Many fields of science have traditionally focused either on single discrete elements or large statistical collections where many theories have been successfully applied. In the field of physics for example, Quantum Mechanicsmesoscale) is not well described by either theory. Similarly, psychologists focus heavily on the behavior and mental processes of the individual while sociologists study the behavior of large societal groups, but what happens when only 3 people are interacting, this is the mesoscale.
describes very well phenomena on the atomic to nanoscale while classical Newtonian Mechanics describes the behavior of objects on the microscale and up. However, the length scale in the middle ( Although the term itself is still quite new, the general concept is not. Many fields of science have traditionally focused either on single discrete elements or large statistical collections where many theories have been successfully applied. In the field of physics for example, Quantum Mechanicsmesoscale) is not well described by either theory. Similarly, psychologists focus heavily on the behavior and mental processes of the individual while sociologists study the behavior of large societal groups, but what happens when only 3 people are interacting, this is the mesoscale.
Brain-Computer Interface
in-Computer Interfacing is an attention-grabbing, dynamic and highly inter-corrective explore issue at the interface between medicine, psychology, neurology, therapy-engineering, man-machine interaction, machine learning and signal processing.
BRAIN-COMPUTER INTERFACE SYSTEM :
In this system, Signals from the brain are acquired by electrodes on the scalp, the cortical surface, or from within the brain and are processed to extract specific signal features that reflect the user’s intent. Features are translated into commands that operate a device (e.g., a simple word processing program, a wheelchair, or a neuroprosthesis).
These BCI systems measure specific features of brain activity and translate them into
device control signals
BCI system
• Give answer of the simple questions rapidly
• Manage the environment
• Perform time-consuming word processing.
At the same time, the act of this new technology, measured in rate and accuracy, or in the complete measure, information transfer rate (i.e., bit rate), is self-effacing. Current systems can reach no more than 25 bits/min, even under finest conditions. The eventual value of this new technology will depend largely on the degree to which its information transfer rate can be increased.
BRAIN-COMPUTER INTERFACE SYSTEM :
In this system, Signals from the brain are acquired by electrodes on the scalp, the cortical surface, or from within the brain and are processed to extract specific signal features that reflect the user’s intent. Features are translated into commands that operate a device (e.g., a simple word processing program, a wheelchair, or a neuroprosthesis).
These BCI systems measure specific features of brain activity and translate them into
device control signals
BCI system
• Give answer of the simple questions rapidly
• Manage the environment
• Perform time-consuming word processing.
At the same time, the act of this new technology, measured in rate and accuracy, or in the complete measure, information transfer rate (i.e., bit rate), is self-effacing. Current systems can reach no more than 25 bits/min, even under finest conditions. The eventual value of this new technology will depend largely on the degree to which its information transfer rate can be increased.
Z-Wave
Z-Wave is the interoperable wireless communication standard developed by Danish company Zensys and the Z-Wave Alliance. It is designed for low-power and low-bandwidth appliances, such as home automation and sensor networks
Radio specifications
Bandwidth: 9,600 bit/s or 40,000 bit/s, fully interoperable
Radio specifics
In Europe, the 868 MHz band has a 1% duty cycle limitation, meaning that a Z-wave unit can only transmit 1% of the time. This limitation is not present in the US 908 MHz band, but US legislation imposes a 1 mW transmission power limit (as opposed to 25 mW in Europe). Z-wave units can be in power-save mode and only be active 0.1% of the time, thus reducing power consumption dramatically.
Topology and routing
Z-wave uses an intelligent mesh network topology and has no master node. A message from node A to node C can be successfully delivered even if the two nodes are not within range providing that a third node B can communicate with nodes A and C. If the preferred route is unavailable, the message originator will attempt other routes until a path is found to the 'C' node. Therefore a Z-wave network can span much further than the radio range of a single unit. In order for Z-wave units to be able to route unsolicited messages, they cannot be in sleep mode. Therefore, most battery-operated devices will opt not to be repeater units. A Z-wave network can consist of up to 232 units with the option of bridging networks if more units are required.
Application areas
Due to the low bandwidth, Z-wave is not suitable for audio/video applications but is well suited for sensors and control units which typically only transmits a few bytes at a time.
Radio specifications
Bandwidth: 9,600 bit/s or 40,000 bit/s, fully interoperable
Radio specifics
In Europe, the 868 MHz band has a 1% duty cycle limitation, meaning that a Z-wave unit can only transmit 1% of the time. This limitation is not present in the US 908 MHz band, but US legislation imposes a 1 mW transmission power limit (as opposed to 25 mW in Europe). Z-wave units can be in power-save mode and only be active 0.1% of the time, thus reducing power consumption dramatically.
Topology and routing
Z-wave uses an intelligent mesh network topology and has no master node. A message from node A to node C can be successfully delivered even if the two nodes are not within range providing that a third node B can communicate with nodes A and C. If the preferred route is unavailable, the message originator will attempt other routes until a path is found to the 'C' node. Therefore a Z-wave network can span much further than the radio range of a single unit. In order for Z-wave units to be able to route unsolicited messages, they cannot be in sleep mode. Therefore, most battery-operated devices will opt not to be repeater units. A Z-wave network can consist of up to 232 units with the option of bridging networks if more units are required.
Application areas
Due to the low bandwidth, Z-wave is not suitable for audio/video applications but is well suited for sensors and control units which typically only transmits a few bytes at a time.
Brain Gate
BrainGate was 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. 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. Currently the chip uses 100 hair-thin electrodes that 'hear' neurons firing in specific areas of the brain, for example, the area that controls arm movement. The activity is translated into electrically charged signals and are then sent and decoded using a program, thus moving the arm. According to the Cyberkinetics' website, two patients have been implanted with the BrainGate system.
visual prosthetic
A visual prosthetic is a form of neural prostheses intended to restore lost vision or amplify existing vision. Scientific research since at least the 1950s has investigated interfacing electronics at the level of the retina, optic nerve, thalamus, and cortex. Notable current researchers include Claude Veraart (optic nerve), Richard Normann (cortex), the brothers Alan and Vincent Chow (retina), and a California-based company named Second Sight.
An Implantable Miniature Telescope is one type of visual prosthetic that has met with some success in the treatment of end-stage age-related macular degeneration[1][2][3]. This type of device is implanted in the eye's posterior chamber and works by increasing (by about three times) the size of the image projected onto the retina in order to overcome a centrally-located scotoma or blind spot[2][3].
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