Public Domain Clip Art
http://www.pdclipart.org/index.php
Monday, October 18, 2010
Saturday, August 7, 2010
Hiking
Below are the Good hiking information sources
1. SF south bay and Peninsula
http://www.bahiker.com/
http://openspace.org/
2. Other sites
http://www.slackpacker.com
3. APPs
http://www.everytrail.com/ (has free mobile app to track the route)
App - http://www.everytrail.com/mobile - app available for iphone, andriod, windows mobile, blackberry
1. SF south bay and Peninsula
http://www.bahiker.com/
http://openspace.org/
2. Other sites
http://www.slackpacker.com
3. APPs
http://www.everytrail.com/ (has free mobile app to track the route)
App - http://www.everytrail.com/mobile - app available for iphone, andriod, windows mobile, blackberry
Thursday, April 1, 2010
Computer Data
kilobyte (kB) | 103 | 210 |
megabyte(MB) | 106 | 220 |
gigabyte (GB) | 109 | 230 |
terabyte (TB) | 1012 | 240 |
petabyte (PB) | 1015 | 250 |
exabyte (EB) | 1018 | 260 |
zettabyte (ZB) | 1021 | 270 |
yottabyte (YB) | 1024 | 280 |
Friday, February 19, 2010
Optical basics
Optical Terminology
Optical fiber - 3 components, Core, Cladding, Coating
Fiber types - MM (Multi Mode), SM (Single Mode) (Generally SM is yellow color cable and MM is orange color cable)
Data is sent as light pulses through the optical cable.
Conventional optical networks wave lengths - 850nm, 1310nm, 1550nm.
Light source
WDM - Wavelength Division Multiplexing.
DWDM - Dense Wavelength Division Multiplexing
In DWDM space between channels(wavelengths) is less, so needs good light source to send good signal.
DWDM uses expensive powerful lasers.
DWDM is used for long distance transmissions.
CWDM - Coarse Wavelength Division Multiplexing
In CWDM channels are spaced widely.
oesn't need powerful laser.
Used for shorter/medium distances
OADM - Optical Add Drop Multiplexers.
EDFA - Erbium Doped Fiber Amplifier (used in DWDM to Amplify the signal)
Connectors
Cable Connector type - (SC, LC are widely used)
SM | - Single Mode fiber. |
MM | - Multi Mode fiber. |
WDM | - Wave length Division Multiplexing. |
DWDM | - Dense Wavelength Division Multiplexing. |
CWDM | - Coarse Wavelength Division Multiplexing. |
OADM | - Optical Add Drop Multiplexers. |
EDFA | - Erbium Doped Fiber Amplifier. |
GBIC | - Giga Bit Interface Converter. |
SFP | - Small Form-factor Pluggable). |
O-E-O | - Optical-Electrical-Optical. |
FC | - Fiber Channel. |
OSNR | - Optical Signal to Noise Ratio |
Optical fiber - 3 components, Core, Cladding, Coating
Fiber types - MM (Multi Mode), SM (Single Mode) (Generally SM is yellow color cable and MM is orange color cable)
Data is sent as light pulses through the optical cable.
Conventional optical networks wave lengths - 850nm, 1310nm, 1550nm.
Light source
- 850nm uses LED (Cheap, short distance)
- 1310nm uses LED or laser (Cheap, medium distance)
- 1550nm uses High quality laser(Expensive .
WDM - Wavelength Division Multiplexing.
DWDM - Dense Wavelength Division Multiplexing
In DWDM space between channels(wavelengths) is less, so needs good light source to send good signal.
DWDM uses expensive powerful lasers.
DWDM is used for long distance transmissions.
CWDM - Coarse Wavelength Division Multiplexing
In CWDM channels are spaced widely.
oesn't need powerful laser.
Used for shorter/medium distances
OADM - Optical Add Drop Multiplexers.
EDFA - Erbium Doped Fiber Amplifier (used in DWDM to Amplify the signal)
Connectors
- GBIC - Giga Bit Interface Converter
- SFP - Small Form-factor Pluggable) - upto 4.25 Gbits/s
- XFP - 10 gig support for dieerent protocols
- SFP+ - 10 gig Ethernet and 8 gig FC, modified/updated XFP (SFP+ is small size, low power consumption, less expensive) .
Cable Connector type - (SC, LC are widely used)
Saturday, February 13, 2010
Virtual PDF printer
When you are not connected to printer and if you have webpage/coupon which can be printed only once the you need a virtual PDF printer. After installation virtual pdf printer will install a printer.
Just click print in the browser and select the virtual printer, this will create pdf file.
You can use this application to create pdf files from any application which has print option.
Some of the virtual pdf printer applications are mentioned below
bullzip (Freeware) - http://www.bullzip.com/products/pdf/info.php#download
win2pdf - Free (Free version adds a extra page at the end of the pdf document)
http://www.win2pdf.com/
Just click print in the browser and select the virtual printer, this will create pdf file.
You can use this application to create pdf files from any application which has print option.
Some of the virtual pdf printer applications are mentioned below
bullzip (Freeware) - http://www.bullzip.com/products/pdf/info.php#download
win2pdf - Free (Free version adds a extra page at the end of the pdf document)
http://www.win2pdf.com/
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