Ethiopian multiplication Ethiopian multiplication You are encouraged to solve this task according to the task description, using any language you may know. A method of multiplying integers using only addition, doubling, and halving. Method: Take two numbers to be multiplied and write them down at the top of two columns. For example: 17 × 34 Halving the first column: Doubling the second column: Strike-out rows whose first cell is even: Sum the remaining numbers in the right-hand column: So 17 multiplied by 34, by the Ethiopian method is 578. The task is to define three named functions/methods/procedures/subroutines: one to halve an integer, one to double an integer, and one to state if an integer is even. Use these functions to create a function that does Ethiopian multiplication. References [edit] ACL2 [edit] ActionScript Output: ex. 17 348 68 Strike4 136 Strike2 272 Strike1 544 Keep= 578 [edit] Ada package Ethiopian is function Multiply(Left, Right : Integer) return Integer;end Ethiopian; [edit] Aime [edit] ALGOL 68 Output:
University of South Carolina researchers convert T-shirt into energy storage medium - Images The researchers used a standard T-shirt purchased from a local discount store for their work Image Gallery (8 images) As manufacturers of smartphones and mobile devices strive to make their products increasingly portable, they repeatedly come up against the constraints of existing battery technology. However, Xiaodong Li, a professor at the University of South Carolina (USC) believes that we will soon be able to employ the clothes we wear to help overcome such challenges and to this end, Li has transformed T-shirt material into an energy storage medium which could one day be used to power portable devices. View all Beginning with a standard T-shirt purchased from a local discount store, Li’s team soaked the garment in a solution of fluoride, then dried and baked the fabric at high temperature in an oven, which is designed to exclude oxygen in order to prevent the fabric from igniting. Source: University of South Carolina About the Author Adam is a tech and music writer based in North Wales.
Binary Game Skip to Content | Skip to Footer Cisco Binary Game The Cisco Binary Game is the best way to learn and practice the binary number system. It is great for classes, students and teachers in science, math, digital electronics, computers, programming, logic and networking. It is also a LOT of fun to play for anyone who likes to play fast-paced arcade games. Free Lectures Online Whether your goal is to earn a promotion, graduate at the top of your class, or just accelerate your life, lectures can help get you there. Our archives of lectures cover a huge range of topics and have all been handpicked and carefully designed by experienced instructors throughout the world who are dedicated to helping you take the next step toward meeting your career goals. Lifelong learns can turn their free time turn into self-improvement time. The online lectures on this list are more than lecture notes or a slideshow on a topic -- they were designed for audiences like you, with carefully sequenced themes and topics taught by veteran educators, and often with additional resources for your own independent study. Lecture courses are a valid and vital learning tool, and may be one of the best methods of learning available.
Low Level Bit Hacks You Absolutely Must Know I decided to write an article about a thing that is second nature to embedded systems programmers - low level bit hacks. Bit hacks are ingenious little programming tricks that manipulate integers in a smart and efficient manner. Instead of performing some operation (such as counting the 1 bits in an integer) by looping over individual bits, these programming nuggets do the same with one or two carefully chosen bitwise operations. To get things going I'll assume that you know what the two's complement binary representation of an integer is and also that you know all the the bitwise operations. I'll use the following notation for bitwise operations in the article: & - bitwise and | - bitwise or ^ - bitwise xor ~ - bitwise not << - bitwise shift left >> - bitwise shift right The numbers in the article are 8 bit signed integers (though the operations work on arbitrary length signed integers) that are represented as two's complement and they are usually named 'x'. Here we go. Bit Hack #1. 1. 2.
Why Nikola Tesla was the greatest geek who ever lived Additional notes from the author: If you want to learn more about Tesla, I highly recommend reading Tesla: Man Out of Time Also, this Badass of the week by Ben Thompson is what originally inspired me to write a comic about Tesla. Ben's also got a book out which is packed full of awesome. There's an old movie from the 80s on Netflix Instant Queue right now about Tesla: The Secret of Nikola Tesla. It's corny and full of bad acting, but it paints a fairly accurate depiction of his life.
Bit Twiddling Hacks By Sean Eron Anderson seander@cs.stanford.edu Individually, the code snippets here are in the public domain (unless otherwise noted) — feel free to use them however you please. The aggregate collection and descriptions are © 1997-2005 Sean Eron Anderson. Contents About the operation counting methodology When totaling the number of operations for algorithms here, any C operator is counted as one operation. Compute the sign of an integer int v; // we want to find the sign of v int sign; // the result goes here // CHAR_BIT is the number of bits per byte (normally 8). sign = -(v < 0); // if v < 0 then -1, else 0. // or, to avoid branching on CPUs with flag registers (IA32): sign = -(int)((unsigned int)((int)v) >> (sizeof(int) * CHAR_BIT - 1)); // or, for one less instruction (but not portable): sign = v >> (sizeof(int) * CHAR_BIT - 1); The last expression above evaluates to sign = v >> 31 for 32-bit integers. Alternatively, if you prefer the result be either -1 or +1, then use: sign = (v !
The Power of Technology Visit page > Big Think is a global forum connecting people and ideas. It may be a cliché to say that knowledge is power, but that doesn’t make the statement any less true. We know that there are just 24 hours in a day, that you are bombarded with information, and that the bombardment will only escalate. We believe that not all information is equal. turing 9 Overlooked Technologies That Could Transform The World What I've noticed is that most people don't really pay attention to "science" news, unless it's something that they can see immediately. I think this is at least partially because of the amount of news that comes out daily - whatever we may think about the quality of news, there is just a flood of it, which makes picking out "interesting" items difficult. When I talk about (just for example) the idea of gene therapy, most people think that it is still complete science fiction, as opposed to a very near-term product that will be available. Of course, CSP has been around for years, so it isn't really "new" to the average person. What they don't realize is the way that efficiencies have improved... And electronic currency is still in the "only oddballs use it" phase - people are aware of it, but mostly because of the issues bitcoin has had in the recent past. Finally, of course, for a majority of people, the only science fiction they think of it Star Wars/Trek, or (advanced!)
university lectures computer science Whether your goal is to earn a promotion, graduate at the top of your class, or just accelerate your life, lectures can help get you there. Our archives of lectures cover a huge range of topics and have all been handpicked and carefully designed by experienced instructors throughout the world who are dedicated to helping you take the next step toward meeting your career goals. Lifelong learns can turn their free time turn into self-improvement time. The online lectures on this list are more than lecture notes or a slideshow on a topic -- they were designed for audiences like you, with carefully sequenced themes and topics taught by veteran educators, and often with additional resources for your own independent study. Lecture courses are a valid and vital learning tool, and may be one of the best methods of learning available.
Science In A Scoop: Making Liquid Nitrogen Ice Cream hide captionThe Smitten Ice Cream shop in the Hayes Valley of San Francisco serves fresh ice cream with one novel ingredient: liquid nitrogen. The shop is located inside of a repurposed shipping container. Alan Greenblatt/NPR Robyn Sue Fisher's ice cream shop, Smitten, in San Francisco's Hayes Valley, may at moments resemble a high school chemistry lab, but that's because Fisher uses liquid nitrogen to freeze her product. Nitrogen is "a natural element," she notes. What makes it essential to Smitten is the ability to make ice cream fresh to order. Because servings are made on the spot, each one requires just a few ingredients. The mint chip, for example, contains just organic cream and milk, mint and a dash of salt. "This is the best ice cream I ever had," says my son, who is only 7 but already an experienced ice cream taster, as he spoons his way through an order of chocolate. He's not alone in his opinion. Of course, there's nothing new about making ice cream with liquid nitrogen.