Linus

Standard Paper Size

2018-01-10T19:43:00.002-08:00

Standard Paper Size

Small paper size is A10 and if we double the width of A10 then we get A9. This process is repeated untill 4A0 size.

Size	W x H (mm)	W x H (in)
4A0	1682 x 2378 mm	66.2 x 93.6 in
2A0	1189 x 1682 mm	46.8 x 66.2 in
A0	841 x 1189 mm	33.1 x 46.8 in
A1	594 x 841 mm	23.4 x 33.1 in
A2	420 x 594 mm	16.5 x 23.4 in
A3	297 x 420 mm	11.7 x 16.5 in
A4	210 x 297 mm	8.3 x 11.7 in
A5	148 x 210 mm	5.8 x 8.3 in
A6	105 x 148 mm	4.1 x 5.8 in
A7	74 x 105 mm	2.9 x 4.1 in
A8	52 x 74 mm	2.0 x 2.9 in
A9	37 x 52 mm	1.5 x 2.0 in
A10	26 x 37 mm	1.0 x 1.5 in

Travel: Death Valley

2018-01-08T22:27:00.000-08:00

Travel: Death Valley

Death Valley national park is at the border of California and Nevada. it has the lowest area, The hottest temperature ever recorded on Earth, It is Largest national park on lower 48 states. Its around 120 miles from las vegas.

Death valley national park has diverse environment even though its in desert. it has sand dunes, slat flats, mountains, valleys.

Following are the attractions in death valley

1. Mesquite Flat Sand dunes
2. Furnace Creek Visitor Center
3. Badwater Basin
4. Artist's Palette
5. Devils Golf Course
6. Natural Bridges Trail
7. Zabriskie Point
8. Dantes view
9. Borax museum
10. Race Track
11. Ubehebe Crater
12. Scottys Castle - road closed

There are several other places you can see in Death valley.

Below is the map of some of the important attractions.

Travel: Antelope Canyon

2018-01-03T19:10:00.000-08:00

Antelope Canyon

Antelope Canyons are "slot"canyons (slot canyons formed by water rushing thought the rocks and they are narrow and deeper. Check Wikipedia for more about slot canyons https://en.wikipedia.org/wiki/Slot_canyon). This post only talks about traveling information, read online for more about the canyons.

Antelope Canyons are in Page, AZ which is a small town near Utah border. There are several other slot canyons in the area (in Utah) but antelope canyons are more popular. These canyons can be accessed only by guided tours.

There are two canyons in page, "Upper antelope canyon" and "Lower antelope canyon". To access lower antelope canyon, we need to climb down stairs. So people with mobility issues or cant climb stairs can take upper canyon tours. Most of the tour buses offer upper canyon tour, so the tickets to upper canyon are sold out early. Since these canyons are popular, tour get sold out often, advanced reservation is recommended. There are two tour operators for lower antelope canyon and three tour operators for upper antelope canyon. Reserve the tour tickets in advance by calling them or online.

All the companies offer two types of tours, sightseeing tours and photography tours. photography tours allow to take tripods and recommended for professional photographers.

These canyons are in Native indian reservation, so entrance fee need to be paid along with tour fee.

When we visited in dec 2017, sightseeing tour for lower antelope canyon for adult is $25 and entrance fee is $8 (total $33) and was told that the tour prices are going up in 2018. These are guided tours and there will be a guide for every 15 people. In summer it will be too hot and crowded.

Tips:

- Advanced tour ticket reservation is recommended.

- Choose mid day time for tour, canyons colors pop out when there is sun light.

- Change your camera settings to get the colors (in iphone change filter to chromo/vivid)

You can also visit the following places when visiting antelope canyons

- Horse shoe bend

- Glen canyon Dam

- Wahweep overlook

- Lake powell

Tour
Lower Antelope canyon
Dixie Ellis - www.antelopelowercanyon.com 928 640 1761
Ken's Tours - www.lowerantelope.com 928 606 2168

Upper Antelope canyon
Antelope slot canyon tours - www.antelopeslotcanyon.com 928 645 5594

Antelope canyon - www.antelopecanyon.com 928 645 9102

Navajo antelope canyon - www.navajoantelopecanyon.com 928 380 1874

Navajo tours - www.navajotours.com 928 310 9458 (not sure if this is same as third one)

Also check www.lakepowelllife.com for more information.

Photos

Lower Antelope Canyon

Horse Shoe Bend

wahweep overlook

Glen Canyon dam

US School information

2013-10-23T15:12:00.001-07:00

US school boundaries and school ratings can be found in the following link
http://www.hometownlocator.com/

For california use below link.
http://california.hometownlocator.com/schools/

This will give school boundary when you give address.

U.S Visas

2011-07-20T12:21:00.000-07:00

Below are the different types of US visas

A-1	Diplomats
A-2	Foreign Govt officials
A-3	Servants of A-1 and A-2

B-1	Bussiness visitor
B-2	Tourist visitor

C-1, C-2, C-3	Foreigners in Transit
C-1	Foreign travelers in transit through US
C-2	Foreign travelers in transit to UN headquarters
C-3	Foreign Govt Officials and Family in transit through US

D-1, D-2	Crewmen
D-1	Crew members who land temporarily and depart on the same ship or plane
D-2	Crew members who land temporarily and depart on the another ship or plane

E-1	Treaty Trades and family
E-2	Treaty Investors
E-3	Australian Speciality workers

F-1	Student
F-2	Family member of F-1

G-1 to G-4	International organization Staff
G5	Servents of G-1 to G-4

H-1B	Speciality Workers
H-1B1	Chileans and Singaporeans
H-1C	Registered Nurse
H-2A	Agricultural Worker
H-2B	Seasonal Worker
H-3	Trainees
H-4	Family of H-1, H-2, H-3

I	Foreign News media

J-1	Exchange visitor
J-2	Family member of J-1

K-1	Fiance or Fiancee
K-2	Childern of K-1
K-3	Spouses of US citizens
K-4	Childern of K-3

L-1	Intra company transfer
L-2	Family member of L-1

M-1	Vocational student
M-2	Family member of M-1

N-8	Parent of SK3
N-9	Child of N-8

O-1	Extraordinary Ability
O-2	Support staff of O-1
O-3	Family of O-1, O-2

P-1	Athletes or Entertainers
P-2	Artists or Entertainers
P-3	Artists or Entertainers
P-4	Family of P-1, P-2, P-3

Q-1	Cultural Exchange
Q-2	Irish national
Q-3	Family member of Q-1

R-1	Religious Workers
R-2	Family member of R-1

S-1 to S-7	Informants to US govt

T-1	Victims of Trafficking
T-2	Spouse of T-1
T-3	Childern of T-1
T-4	Parents of T-1
TN	NAFTA Professional (Canada, Mexico)
TD	Family member of TN

U-1	Victims of Crime
U-2	Spouses of U-1
U-3	Childern of U-1
U-4	Parents of U-1

V-1	Spouses of US residents
V-2	Childern of US residents
V-3	Childern of V-1 or V-2

Links

2011-05-29T12:37:00.000-07:00

1. Events

http://upcoming.yahoo.com/
http://www.artsopolis.com/http://savvycities.com/
2. Travel
http://www.trekaroo.com
travel.yahoo.com

3. Hiking
http://www.bahiker.com/
http://www.everytrail.com/

4. Other

Apartment searching site - padmapper.com/

2011-05-13T10:56:00.000-07:00

http://www.padmapper.com/

Good site to search apartments for rent. It displays posting from several site (like craigslist etc) on google map.

QR code

2011-01-24T21:22:00.000-08:00

Quick Response code is a square bar code. QR codes can store lot of data compared to barcodes.
QR codes can store url's, email address, small emails, vcard etc.

QR codes can be read by using mobile phone application

QR-Code Data Capacities
Numeric only Max 7,089 characters
Alphanumeric Max 4,296 characters
Binary (8 bits) Max 2,953 bytes

QR-Codes dont need to scan from one particular angle, they can be read from any angle.

Ethernet cable

2011-01-22T13:29:00.001-08:00

Inside the ethernet cable, there are 8 color coded wires.
These wires are twisted into 4 pairs of wires.
One wire in the pair is solid colored wire and the other is primarily white wire with a colored stripe.

T568A and T568B are the two color codes used for wiring eight-position RJ45 modular plugs.
Both are allowed under the ANSI/TIA/EIA wiring standards.
The only difference between the two color codes is that the orange and green pairs are interchanged.

Pin Numbering in the clip

Signals on the Pins

In straight cable pin 1 to 8 on one side is connected to pin 1 to 8 on other side

1 <--> 1
2 <--> 2
3 <--> 3
4 <--> 4
5 <--> 5
6 <--> 6
7 <--> 7
8 <--> 8

In Crossover cable Tx is connected to Rx (ie Tx+ to Rx+, Tx- to Rx-, Rx+ to Tx+, Rx- to Tx-)

1 <--> 3
2 <--> 6
3 <--> 1
4 <--> 4
5 <--> 5
6 <--> 2
7 <--> 7
8 <--> 8

In Rolled or rollver cables pin 1 to 8 on one side is connected to pin 8 to 1 on other side

1 <--> 8
2 <--> 7
3 <--> 6
4 <--> 5
5 <--> 4
6 <--> 3
7 <--> 2
8 <--> 1

If same type of devices needs to be connected cross cable is used. ie to connect PC to PC, switch to switch or router to router.

Straight cable is used if both sides of the cables are different types of devices. ie to connect PC to switch or PC to router or switch to router etc.

Gigabit Ethernet ports which support auto sensing (MDI/MDIX) doesn't require cross cable. Straight cable can be used.

Difference Between Similar Terms and Objects

2011-01-22T13:17:00.000-08:00

To find Difference Between Similar Terms and Objects see http://www.differencebetween.net/

Clip art

2010-10-18T16:13:00.000-07:00

Public Domain Clip Art

http://www.pdclipart.org/index.php

Hiking

2010-08-07T13:44:00.000-07:00

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

Computer Data

2010-04-01T11:22:00.000-07:00

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

Optical basics

2010-02-19T10:39:00.000-08:00

Optical Terminology

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)

Virtual PDF printer

2010-02-13T13:41:00.001-08:00

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/

Basic application software install on clean OS install

2009-11-06T17:17:00.000-08:00

If you do clean install of windows and want to install all the basic software required, instead of downloading all software and installing them one by one, go to http://ninite.com/ select the software you want and download the installer. Run the installer, it will install all the selected software on your PC. This is much faster than individual download and install.

GSM phones

2009-01-28T11:32:00.000-08:00

GSM (Global System for Mobile communications) operate in 4 frequencies.
850, 900, 1800, 1900 MHz

If a phone is quad band phone, it supports all 4 frequencies. so it works any where in the world.

If it is not quad band phone we need to check what frequencies the phone supports and check if the operators in the area where you are planning to use the phone operates in that frequencies.

Suppose if you have a tri band phone which operates in 850/1800/1900, the phone doesnt works with operators that use 900 frequency.

In US ATT operates with both 850 and 1900 frequencies and T-Mobile operates at 1900.
In India Airtel, BSNL, IDEA operates at 900 frequency and Vodafone, Reliance, tata indicom operates at 1800 frequency.

If you take a tri band phone with 850/1800/1900 phone which worked in US with ATT or T-mobile, In india this phone works only with Vodafone, Reliance, tata indicom. it doesnt works with Airtel, BSNL, IDEA.

check the below link for more information on frequencies operated by various service provides in different countries.

http://www.gsmworld.com/roaming/gsminfo/index.shtml

Freeware

2008-12-03T14:05:00.000-08:00

List of Best Freeware by category is found in below link

http://www.techsupportalert.com/pc-tools.html

Flash Memory - 1

2008-11-17T21:53:00.000-08:00

Flash memory is non-volatile memory, which means that no power is needed to maintain the information stored in the chip.

Technology:
It is a specific type of EEPROM (Electrically Erasable Programmable Read-Only Memory) .

It comes in NAND and NOR types. NOR-type has long erase and write times, but provides full address and data buses, allowing random access to any memory location. while NAND-type has faster erase and write times, and requires a smaller chip area per cell, (thus allowing greater storage densities and lower costs per bit than NOR flash). it also has up to ten times the endurance of NOR flash. However, the I/O interface of NAND flash does not provide a random-access external address bus.
NOR type flash is for faster read access (can be used where ROM is required), NAND type is used for storage (can replace hard drives, CD, DVD etc).

Advantages:
Unlike in hard drives theres no moving part in flash memory, so it requires less power, and more shock resistance. so flash is becoming more popular in portable devices.
less latencies compared to hard drive.

Limitations:
1. with flash memory is it has a finite number of erase-write cycles.
2. limited capacity compared to hard drives
but the number of cycles, capacity increases with technology improvements.

Transfer Rates:
Commonly advertised is the maximum read speed. it is represented in "x" format or MB/s
1x is equal to 150 kilobytes per second.

So a 100x memory card goes to 150 KB x 100 = 15000 KB per second = 14.65 MB per second.

--------------------------
Rating   Speed (MB/s)
-------------------------
6x        0.9
32x       4.8
40x       6.0
66x       10.0
100x      15.0
133x      20.0
150x      22.5
200x      30.0
-----------------------

Flash memory comes in different types, capacities, shapes and sizes.
different companies makes them in different varieties. below are list
of popular flash memory types.

Compact flash from sandisk

Memory Stick from sony/sandisk

Secure digital (SD) from panasonic, toshiba, sandisk

xD from olympus, fujifilm

USB flash drives from various manufactures, and Universally compatible across all computer platforms using USB 1.1/2.0

Compact Flash

Memory stick
1. standard (50 mm x 21.5 mm x 2.8 mm),
2. Duo(31 mm x 20 mm x 1.6 mm),
3. Pro Duo(31 mm x 20 mm x 1.6 mm)
4. Micro(15 mm x 12.5 mm x 1.2 mm)

 1          2        3     4

SD, mini SD, micro SD, SDHC

SDHC extension to SD, it has capacities exceeding 2GB
SDHC has speed class rating
class 2 - 2MB/s
class 4 - 4MB/s
class 6 - 6MB/s

xD (standard, type M, type H)
Thin and small (20 mm × 25 mm × 1.78 mm)

USB (no standard size, comes in various sizes and capacities)

DVD regeions

2008-11-17T21:25:00.000-08:00

NTSC (National Television Standards Committee) is a standard
used in North America and Japan. It has the ability to display
up to 525 lines of resolution.

PAL (Phase Alternating Line), a standard used almost everywhere
else in the world, has the ability to display 625 lines of resolution.

SECAM (Sequential Color Memory) is used sparingly around the
world and can be found in France, parts of Greece, Eastern Europe,
Russia, Africa and a few other parts of the world. However, any
SECAM country can display PAL tapes in full color, but not all PAL
countries can display all SECAM tapes in color. Only if they are true
SECAM and not MESECAM can those VCR's display SECAM.

Region 01
U.S., U.S. Territories, Canada

Region 02
Albania, Andorra, Austria,
Bahrain, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria,
Canary Islands, Croatia, Cyprus, Czech Republic,
Denmark, Egypt, Estonia, European Union,
Faroe Islands, Finland, France, France, Georgia,
Germany, Gibraltar, Greece, Greenland, Hungary,
Iceland, Iran, Iraq, Ireland, Israel, Italy, Japan, Jordan,
Kuwait, Latvia, Lebanon, Liechtenstein, Lithuania,
Luxembourg, Macedonia (the Former Yugoslav Republic), Malta, Moldova,
Principality of Monaco, Netherlands, Norway, Oman, Poland, Portugal,
Qatar, Romania, Russian Federation, San Marino, Saudi Arabia, Slovakia,
Slovenia,South Africa, Spain, Sweden, Switzerland, Syrian Arab Republic,
Turkey, Ukraine, United Arab Emirates, United Kingdom,
United Kingdom (Channel Islands), Vatican City State, Yemen, Yugoslavia

Region 03
Southeast Asia, East Asia (including Hong Kong)

Region 04
Australia, New Zealand, Pacific Islands, Central America, Mexico, South America, Caribbean

Region 05
Former Soviet Union, Indian Subcontinent, Africa (also North Korea, Mongolia)

Region 06
China

Region 07
Reserved

Region 08
Special international venues (airplanes, cruise ships, etc.)

Reliability: nines

2008-11-17T20:58:00.000-08:00

The uptime and reliability of a system is measured in "nines". "Five nines" means 99.999% availability, which means downtime of approximately five minutes and fifteen seconds per year.

see the below table


-----------------------------------------------------------
                  per year      per month      per week
-----------------------------------------------------------
98%               7.30 days     14.4 hours     3.36 hours
99%               3.65 days     7.3 hours      1.68 hours
99.5%             1.83 days     3.6 hours      50.4 min
99.9%             8.76 hours    43.2 min       10.1 min
99.99%            52.6 min      4.32 min       1.01 min
99.999%           5.26 min      25.9 sec       6.05 sec
99.9999%          31.5 sec      2.59 sec       0.605 sec
-----------------------------------------------------------

Display Standards

2008-11-17T20:48:00.000-08:00

Different display standards
image shows different video display standards and their aspect ratios

from wikipedia