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Sunday, April 21, 2019

What is the importance of 12/31/1969 to the IT world?

What is the importance of 12/31/1969 to the IT world?

  • New Years Eve
  • The first release of Windows 1.0 was shipped
  • The Beginning of That 70s Show
  • The beginning date of Unix and where it starts counting time from 
What is the importance of 12/31/1969 to the IT world?

EXPLANATION

 Linux is following the tradition set by Unix of counting time in seconds since its official "birthday," -- called "epoch" in computing terms -- which is Jan. 1, 1970.

A more complete explanation can be found in this Wired News article. It explains that the early Unix engineers picked that date arbitrarily, because they needed to set a uniform date for the start of time, and New Year's Day, 1970, seemed most convenient.

 The Unix epoch is midnight on January 1, 1970. It's important to remember that this isn't Unix's "birthday" -- rough versions of the operating system were around in the 1960s. Instead, the date was programmed into the system sometime in the early '70s only because it was convenient to do so, according to Dennis Ritchie, one of the engineers who worked on Unix at Bell Labs at its inception.

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How do you block a user from opening a folder, when that group has full permissions?

How do you block a user from opening a folder, when that group has full permissions?

  • In AD uncheck Allow on the User in the group
  • Explicit Deny User on the folder 
  • Click Stop Permissions on the User in AD
  • Create Exception on the folder for User 
 

EXPLANATION

Access Based Enumeration will be your best solution. That way even though the user account may be able to see a share, they can't see any of the contents. You could go a step further and create a Deny-SMB security group with that account as its sole member and then nest all of your other user level security groups in a group that is granted permissions to access shares.


Overall, more information is going to make the best possible route easier to recommend

Please report us in comment box if answer is incorrect.
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Friday, April 19, 2019

Within HTTP, which header includes the URL of the web page containing the link that initiated the current request?

Within HTTP, which header includes the URL of the web page containing the link that initiated the current request?

  • Referer
  • Host
  • Post
  • Send 


 EXPLANATION

HTTP referer


The HTTP is an HTTP header field that identifies the address of the webpage that linked to the resource being requested. By checking the referrer, the new webpage can see where the request originated.
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What technology do Multimode fiber cables use to transmit data?

What technology do Multimode fiber cables use to transmit data?

  • Fluorescents
  • LEDs
  • Magic
  • Lasers 
What technology do Multimode fiber cables use to transmit data?

 EXPLANATION

According to Wiki.

Multi-mode fibers are described by their core and cladding
diameters. Thus, 62.5/125 Âµm multi-mode fiber has a core size of 62.5 micrometres (µm) and a cladding diameter of 125 Âµm. The transition between the core and cladding can be sharp, which is called a step-index profile, or a gradual transition, which is called a graded-index profile. The two types have different dispersion characteristics and thus different effective propagation distance.[6] Multi-mode fibers may be constructed with either graded or step-index profile.[7]
In addition, multi-mode fibers are described using a system of classification determined by the ISO 11801 standard — OM1, OM2, and OM3 — which is based on the modal bandwidth of the multi-mode fiber. OM4 (defined in TIA-492-AAAD) was finalized in August 2009,[8] and was published by the end of 2009 by the TIA.[9] OM4 cable will support 125m links at 40 and 100 Gbit/s. The letters "OM" stand for optical multi-mode.
For many years 62.5/125 Âµm (OM1) and conventional 50/125 Âµm multi-mode fiber (OM2) were widely deployed in premises applications. These fibers easily support applications ranging from Ethernet (10 Mbit/s) to gigabit Ethernet (1 Gbit/s) and, because of their relatively large core size, were ideal for use with LED transmitters. Newer deployments often use laser-optimized 50/125 Âµm multi-mode fiber (OM3). Fibers that meet this designation provide sufficient bandwidth to support 10 Gigabit Ethernet up to 300 meters. Optical fiber manufacturers have greatly refined their manufacturing process since that standard was issued and cables can be made that support 10 GbE up to 400 meters. Laser optimized multi-mode fiber (LOMMF) is designed for use with 850 nm VCSELs.
The migration to LOMMF/OM3 has occurred as users upgrade to higher speed networks. LEDs have a maximum modulation rate of 622 Mbit/s because they cannot be turned on/off fast enough to support higher bandwidth applications. VCSELs are capable of modulation over 10 Gbit/s and are used in many high speed networks.
Some 200 and 400 Gigabit Ethernet speeds use wavelength-division multiplexing (WDM) even for multi-mode fiber which isn't specified up to and including OM4. In 2017, OM5 has been standardized by TIA and ISO for WDM MMF, specifying not only a minimum modal bandwidth for 850 nm but a curve spanning from 850 to 953 nm.
Cables can sometimes be distinguished by jacket color: for 62.5/125 Âµm (OM1) and 50/125 Âµm (OM2), orange jackets are recommended, while aqua is recommended for 50/125 Âµm "laser optimized" OM3 and OM4 fiber.[4] Some fiber vendors use violet for "OM4+". OM5 is officially colored lime green.
VCSEL power profiles, along with variations in fiber uniformity, can cause modal dispersion which is measured by differential modal delay (DMD). Modal dispersion is caused by the different speeds of the individual modes in a light pulse. The net effect causes the light pulse to spread over distance, introducing intersymbol interference. The greater the length, the greater the modal dispersion. To combat modal dispersion, LOMMF is manufactured in a way that eliminates variations in the fiber which could affect the speed that a light pulse can travel. The refractive index profile is enhanced for VCSEL transmission and to prevent pulse spreading. As a result, the fibers maintain signal integrity over longer distances, thereby maximizing the bandwidth.

SOURCE

https://en.wikipedia.org/wiki/Multi-mode_optical_fiber

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Which of the following is a near universal text format?

Which of the following is a near universal text format?

  • Plain Text
  • PDF
  • Word 97-2003
  • Rich Text Format 

Which of the following is a near universal text format?

EXPLANATION

Word 97-2003 Document So you've got Word 2010, but your parents are still plugging along with Word 97. The latter can't open documents created by the former (not without a converter, anyway), but at least Word lets you save files using the older formats. Some kinds of formatting may get lost in translation, but this should work for most kinds of documents.


Rich Text Format RTF might best be described as a "universal word-processing format," as it's supported by just about every word processor. However, unlike plain text, it retains basic formatting information, like font sizes and styles.

PDF Adobe's Portable Document Format also has universal appeal, as it can be opened using any number of viewers (including, most commonly, Adobe Reader). You'd use PDF to produce your document in a read-only format, meaning it couldn't easily be edited. It's also a good way to distribute documents online, as most browsers can view PDFs without the need to download them fist.


Plain Text Just like it sounds, this format saves only the raw text--no formatting, no hidden codes, just your words. You might use this to export text that needs to be imported into another program, like a blog tool or text editor--something that won't like all of Word's underlying extras.


 
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In Windows, If you want to put a windows on a side, what key command will move it for you?

In Windows, If you want to put a windows on a side, what key command will move it for you?

  • Windows-Directional arrow
  • Ctrl-Shift-Directional arrow
  • Alt-Shift-Directional arrow
  • Ctrl-Windows-Directional arrow 
In Windows, If you want to put a windows on a side, what key command will move it for you?

EXPLANATION

Windows 7

This feature is built in, and it's called Aero Snap. You can use the following keyboard shortcuts to get the behavior you want:

  • Win + moves the current window to the left half of the screen.
  • Win + moves the current window to the right half of the screen.
  • Win + maximes the current window.

Windows XP and Vista

GridMove allows you to setup regions to snap windows to via a shortcut key. I mapped Win + 1 to move a window to the left half of the screen and Win + 2 to use the right half.
AeroSnap makes Windows 7's native keyboard shortcuts available in Windows Vista and Windows XP.

Mac OS X

Cinch, SizeUp (both unlimited free trials) and TwoUp (discontinued – available here) from Irradiated Software all accomplish this task perfectly. SizeUp adds some extra features, including multiple monitor support.

 


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Which computer has been designed to be as compact as possible?


Which computer has been designed to be as compact as possible?
  • Super computer
  • Mainframe
  • Mini
  • Micro computer

Which computer has been designed to be as compact as possible?


EXPLANATION

Micro computer : A microcomputer is a small, relatively inexpensive computer with a microprocessor as its central processing unit. It includes a microprocessor, memory, and minimal input/output circuitry mounted on a single printed circuit board. 

SOURCE

https://www.examveda.com/which-computer-has-been-designed-to-be-as-compact-as-possible-10133/
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