English, Web Design: what does deprecated mean?

Tutoring English, fresh vocabulary keeps writing interesting. The tutor brings up a term he reads in connection with computer science.

deprecated (adj)

viewed unfavourably, viewed with disapproval.

In computer science, certain ways of writing code can become deprecated after newer, preferred ways supplant them. The deprecated code may continue to be supported for a time, but after being labelled “deprecated”, it’s vulnerable to sudden dysfunction.

Source:

developer.mozilla.org

Gilmour, Lorna (ed). Collins Essential Canadian English Dictionary & Thesaurus. Glasgow: HarperCollins, 2006.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Computer networks: what is a switch?

More technology self-tutoring: the tutor explains his understanding of switch, a term he’s found tricky to define.

For background, my post from April 2, as well as my post from yesterday, connect with today’s topic.

Switches can be used in a variety of ways, so a simple conception only explains one application. However, I find this idea helpful:

Imagine a self-contained local network of computers physically connected. A given member can send a message to a specific other, or to all others at once. Then, the simplest central connection among these computers is a switch.

A switch is different from a hub (once again, my post from yesterday) in that the switch can forward a message to a specific intended recipient, whereas the hub just forwards it to everyone.

Source:

askleo.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Computer science, networks: what is a hub?

More technology self-tutoring: the tutor investigates the term hub in networking.

hub (in computer network):
a central device to which computers can be connected to form a local network. Data the hub receives from one computer will be forwarded to all the others to which it’s connected.

Source:

askleo.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Computer science, networks: what is a Peer-to-peer (P2P) network?

More self-tutoring about computer networks: the tutor shares the definition of peer-to-peer network.

Peer-to-Peer (P2P) network:

A network in which any computer is directly connected to any other, rather than through a server. The premise of P2P seems to be that the members are physically connected by wire.

The arrangement could be two computers connected, for example, by USB. It could also be a larger set of computers all connected along one main rail.

Source:

www.computerworld.com

www.w3schools.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Networking, OSI model: Layer 2 vs Layer 3

Reading about networks leads to self-tutoring: the tutor mentions some ideas about Layer 2 vs Layer 3 in computer networks.

As I understand, Layer 2, aka the link layer, is associated with data transmission in the context of frames. A simplified point of view about it imagines physically connected devices communicating. In broadcast mode, every member forwards all its output to every other member. However, output can be sent to only a specific member. Connected members have no nodes between them; each member is directly connected to any other. The Layer 2 network is self-contained.

Layer 3 uses packets, rather than frames, to organize data. It’s populated by routers. In Layer 3, a given data packet has one intended recipient; the others on the network will not see it. The router conducts each packet to its appropriate destination. Layer 3 is needed when there are intervening nodes between ones that want to communicate – hence, the need for routing the packets of information to their specific destinations. Layer 3 is the context for communication to happen between different networks.

Source:

www.wideband.net.au

stackoverflow.com

www.networkworld.com

networkengineering.stackexchange.com

askleo.com

www.computerworld.com

documentation.meraki.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Video games, graphics: what is ambient occlusion?

More self-tutoring about modern terms: the tutor shares what he learned about ambient occlusion.

ambient occlusion

a way of depicting a scene that shows features darker or lighter based on their exposure to ambient light, rather than a directed light source.

In many settings, such as within a dungeon or room in a deserted building, we often don’t imagine a light source. Therefore, the ambient lighting model makes sense.

Example: With ambient occlusion, a surface that crosses line of sight will be lighter than one running parallel to line of sight.

Source: Techquickie, on youTube

www.w3schools.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Computer science: networking: what is a virtual connection?

In tutoring, definitions are always important. The tutor shares the definition of virtual connection.

virtual connection:

A virtual connection is a software-initiated connection between two nodes in a network. (See yesterday’s post for the definition of a node.)

When you visit a site on the internet from your browser, you establish a virtual connection with that server.

Source:

www.pcmag.com

www.w3schools.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Computer science, networks: what is a node?

Understanding computer networking leads to self-tutoring: the tutor defines node in computer networks.

node (noun):

an endpoint, or else a directing or processing device between endpoints. The endpoint could be a PC, printer, scanner, server, etc: at an endpoint, content either enters the network or is received there.

The directing device could be a router.

There are different points of view about nodes depending on the type of network, etc. However, one point of view imagines a node as a point where information enters, is received, or is processed in some way to make it available to its end user. A router, for instance, directs information to its various specific requesters.

Source:

audiopedia

www.lifewire.com

www.lifewire.com

whatismyipaddress.com/router

www.howtogeek.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Computer science: value parameter vs variable parameter

Tutoring computer science, the difference between variable and value parameters is interesting. The tutor illustrates it.

value parameter:

the parameter’s value is sent to the function or method, but the function can’t change the parameter itself. For instance:

j=5

function(value_parameter p){

p=p+1;

output “p=” p;
output “j=” j;
}

function(j);

will give the output

p=6
j=5 //j is still 5

variable parameter

the parameter itself is sent to the function. Changes made to it by the function will persist in the external program.

j=5

function(variable_parameter p){

p=p+1;

output “p=” p;
output “j=” j;
}

function(j);

will give the output

p=6
j=6 //j has been changed to 6 by the function

Source:

docwiki.appmethod.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Perl programming: can you increment a counter variable by a decimal?

Tutoring programming, you encounter all kinds of instances. The tutor mentions, with Perl, incrementing a counter variable in a for loop by a decimal amount.

Can you increment a counter variable by a decimal amount? In my experience, with Perl, you can:

for($i=0;$i<0.1;$i+=0.01){ print "Now i is ".$i."\n"; }

prints, in my terminal,

0.01
0.02
0.03
[and so on]

Source:

McGrath, Mike. Perl in easy steps. Southam: Computer Step, 2004.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.