|“The NAND gate has the property of functional completeness. That is, any other logic function (AND, OR, etc.) can be implemented using only NAND gates. An entire processor can be created using NAND gates alone.’
” —Steven Colyer
Today’s WhatIs.com Word of the Day is quad gate. A quad gate an IC (integrated circuit or chip) containing four logic gates. The quad NAND gate is of particular interest, because any of the basic logic functions can be derived by connecting multiple NAND gates together. This feature makes the quad NAND gate useful as a “universal digital substitute,” and also can help students learn how digital logic circuits work.
Today’s WhatIs.com Word of the Day is minification. It’s the the removal of unnecessary characters from source code. The term minification is often associated with interpreted scripted languages that are deployed and transmitted over the Internet.
|“By convention, stacks usually grow down. This means that the stack starts at a high address in memory and progressively gets lower.” — Ian Wienand
I have to take a minute here to plug Ian Wienand’s free online book “Computer Science from the Bottom Up.” If you’re interested in looking underneath the hood, this is the book to help you understand what you’re seeing.
Mr. Wienand explains the concept of a stack as clearly as anyone I’ve ever heard or read:
A stack is generic data structure that works exactly like a stack of plates; you can push an item (put a plate on top of a stack of plates), which then becomes the top item, or you can pop an item (take a plate off, exposing the previous plate).
Stacks are fundamental to function calls. Each time a function is called it gets a new stack frame. This is an area of memory which usually contains, at a minimum, the address to return to when complete, the input arguments to the function and space for local variables.
|“At some point in the future, I think we’re likely to see most of the power and cabling overhead with the raised floor used mainly for water piping to serve cooling needs of close-coupled cooling systems.” — Robert McFarlane|
Today’s WhatIs.com Word of the Day is raised floor, a data center construction model in which a slightly higher floor is constructed above the building’s original concrete slab floor, leaving the open space created between the two for wiring or cooling infrastructure.
Although raised floors have been the norm in the modern-day data center, we have recently begun to see a return to construction that puts power and cooling above the hardware instead of below it. It’s being pushed as being a “green data center” solution. For one thing, putting the cooling system in the ceiling and allowing physics to let the cold air fall uses less power.
|“The adjustment [to data visualization tools] been a difficult one, both operationally and culturally. Business users trust their spreadsheets and don’t want to give them up.” — Ron Van Zanten|
Today’s WhatIs.com Word of the Day is data visualization, a general term for technology that provides a graphical representation of data. Data visualzation tools have executive dashboards that translate raw data numbers into colorful pie charts and bar graphs for faster, easier consumption of data.
|“Text analytics — also known as text mining or text data mining — helps organizations identify and understand what people think about them, their products and their services. The software, which combines advanced search techniques with speech-pattern-recognition capabilities, allows users to quickly scour mountains of unstructured or free-form text in the hope of identifying trends in customer sentiment that will ideally lead to positive change.”
Mark Brunelli, Text analytics tools require serious devotion to customers
|“Predictive modeling allows for more informed marketing decisions and more effective resource allocation. Instead of blasting the same offers to everyone, you can target multiple offers by segment or focus on particular customer groups based on current or potential value.”
Colleen Ryan, Predictive Modeling: Turning Data Into Insight
Today’s WhatIs.com Word of the Day is predictive modeling. It’ s used a lot in customer relationship management (CRM) and enterprise resource planning (ERP).
Colleen Ryan does an excellent job explaining how predictive modeling works. While it might seem like voodoo, it’s really mathematical. Remember learning about probability and outcome back in sixth grade? Well, in the real world, its not just about rolling a pair of dice.
Or maybe it is.
Maybe trying to predict outcomes of any kind is still just…gambling.
|“For many years, open source was seen as a trailing effort to proprietary projects. In the big data/NoSQL space, this has been turned on its head. Cassandra is a really good example of how openness is leading the development of next-generation infrastructure technology.” — Joe Brockmeier|
Today’s WhatIs.com Word of the Day is Cassandra, a highly-scalable NoSQL open source database system that was created for Facebook but has since become a top-level project over at the Apache Software Foundation. Cassandra’s claim to fame? She can handle hundreds of thousands of requests per second. According to Apache, the largest Cassandra production cluster as of this writing exceeds 300 terabytes of data over 400 machines.
|“Coaxial cables use a single copper conductor at the center, insulated by a plastic layer and a braided metal shield, which blocks interference. Coaxial cables are hard to install, but can support greater cable lengths than twisted pair.” — Carrie Higbie|
Today’s WhatIs.com Word of the Day is conductor. Conductivity, in general, is the capacity to transmit something, such as electricity or heat.
An electrical conductor is a substance in which electrical charge carriers, usually electrons, move easily from atom to atom with the application of voltage. A substance that does not conduct electricity is called an insulator or dielectric material.
|“Built on mostly open source software and commodity hardware, Digg dropped its open source MySQL database in favor of Cassandra, a non-relational, “NoSQL” database that was developed by Facebook and handed over to the Apache Software Foundation.” — Rob Barry|
Today’s WhatIs.com Word of the Day is Digg, a social news site that allows members to raise the visibility of stories they like best and bury stories they don’t like. Digg was launched back in 2004.