Communications of the ACM
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How the “Frontier” Became the Slogan of Uncontrolled AI
Artificial intelligence (AI) has been billed as the next frontier of humanity: the newly available expanse whose exploration …
From Daniel Lemire's Blog
What is the space overhead of Base64 encoding?
Many Internet formats from email (MIME) to the Web (HTML/CSS/JavaScript) are text-only. If you send an image or executable file by email, it often first gets encoded...
From Daniel Lemire's Blog
Data scientists need to learn about significant digits
Suppose that you classify people on income or gender. Your boss asks you about the precision of your model. Which answer do you give? Whatever your software tells...
From Daniel Lemire's Blog
Rethinking Hamming’s questions
Richard Hamming is a famous computer scientist. In his talk You and Your Research, Hamming recounts how asked researchers three questions which I paraphrase: What...
From Daniel Lemire's Blog
Science and Technology links (January 26th, 2019)
We are training many more doctors (PhDs) than we need, when looking at the number of new faculty positions. In science, this has been true since at least the 1980s...
From Daniel Lemire's Blog
Science and Technology links (January 19th, 2019)
Losing even just a bit of weight can be enough to restore fertility in women. Digital technology does not appear to have a significant negative effect on teenagers...
From Daniel Lemire's Blog
Faster intersections between sorted arrays with shotgun
A common problem within databases and search engines is to compute the intersection between two sorted array. Typically one array is much smaller than the other...
From Daniel Lemire's Blog
Science and Technology links (January 12th, 2019)
You can buy a 512GB memory card for $140 from Amazon. We have been told for decades to avoid saturated fats, the kind found in meat, cheese and butter. After an...
From Daniel Lemire's Blog
Science and Technology links (January 5th, 2019)
There are nearly 70,000 centenarians in Japan. China’s population fell by 2.5 million in 2018. Obesity is associated with increased senescent cell burden and neuropsychiatric...
From Daniel Lemire's Blog
Memory-level parallelism: Intel Skylake versus Intel Cannonlake
All programmers know about multicore parallelism: your CPU is made of several nearly independent processors (called cores) that can run instructions in parallel...
From Daniel Lemire's Blog
Important science and technology findings in 2018
The Gompertz-Makeham law predicts statistically the mortality rate of human beings. The key takeaway is that it is an exponential function. Every few years, the...
From Daniel Lemire's Blog
Science and Technology links (December 29th, 2018)
Low-dose radiation from A-bombs elongated lifespan and reduced cancer mortality relative to un-irradiated individuals (Sutou, 2018): The US National Academy ofContinue...
From Daniel Lemire's Blog
Science and Technology links (December 22nd 2018)
For equity reasons, many people advocate for double-blind peer review, meaning that the author does not know who the reviewer is, nor does the reviewer know who...
From Daniel Lemire's Blog
Fast Bounded Random Numbers on GPUs
We often use random numbers in software in applications such as simulations or machine learning. Fast random number generators tend to produce integers in [0,232)...
From Daniel Lemire's Blog
Sorting strings properly is stupidly hard
Programming languages make it hard to sort arrays properly. Look at how JavaScript sorts arrays of integers: > v = [1,3,2,10] [ 1, 3, 2, 10 ] > v.sort() [ 1, 10...
From Daniel Lemire's Blog
Science and Technology links (December 15th 2018)
Academic excellence is not a strong predictor of career excellence. There is weak correlation between grades and job performance. Grant reviews the evidence inContinue...
From Daniel Lemire's Blog
Science and Technology links (December 8th 2018)
The energy density of lithium-ion batteries doubled between 1995 and 2005 but only increased by about 15% between 2005 and 2015. It is estimated that there is relatively...
From Daniel Lemire's Blog
Asking the right question is more important than getting the right answer
Schools train us to provide the right answers to predefined questions. Yet anyone with experience from the real world knows that, more often than not, the difficult...
From Daniel Lemire's Blog
Science and Technology links (December 1st 2018)
Autism affects about 1% of the population and four times as many males as females. In older highly educated people, drinking 2 cups of coffee a day is associated...
From Daniel Lemire's Blog
Quickly sampling from two arrays (C++ edition)
Suppose that you are given two arrays. Maybe you have a list of cities from the USA and a list of cities from Europe. You want to generate a new list which mixes...
From Daniel Lemire's Blog