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
To improve your intellectual productivity
We would all like to be smarter, to produce better software, better research papers or better art. It is not difficult to see that, by just about any metric, productivity...
From Daniel Lemire's Blog
Does time fix all?
As an graduate, finding useful references was painful. What the librarians had come up with were terrible time-consuming systems. It took an outsider (Berners-Lee)...
From Daniel Lemire's Blog
On Feeding Your CPU With Data
Can you guess the speed difference between these two lines of code? The first line of code does N additions: for (int i=0; i<N;i++) sum+=arr[i]; The second line...
From Daniel Lemire's Blog
A post-industrial point of view
We can roughly sketch human history as follows: Initially, everything was expensive for human beings. Farming made food cheap. The industrial revolution made goods...
From Daniel Lemire's Blog
The Internet is a product of the post-industrial age
The Internet is on fire with this question: who invented the Internet? A couple of weeks ago, the president of the USA said: Government research created the Internet...
From Daniel Lemire's Blog
Is C/C++ worth it?
We routinely attribute the long battery life and power of our tablets and tiny laptops to better hardware. However, in many cases, this better hardware runs software...
From Daniel Lemire's Blog
Why we make up jobs out of thin air
“We prefer to invent new jobs rather than trying harder and inventing a new system that wouldn’t require everybody to have a job.” (Philippe Beaudoin) In the XXIst...
From Daniel Lemire's Blog
Facts about global warming that you should keep for yourself
I don’t get invited to parties very often. That is, in part, because I cultivate aggressively critical thinking. My wife will testify that I am doubter, an annoying...
From Daniel Lemire's Blog
Bytes or octets?
Quick: what is the definition of a byte (as in two kilobytes)? If you said it is a unit of 8 bits, you failed. Correct answer (according to IEEE 1541): A byte is...
From Daniel Lemire's Blog
Which is fastest: read, fread, ifstream or mmap?
If you program in C/C++, you have many options to read files: The standard C library offers a low-level read function. It is as simple as it gets. The standard...
From Daniel Lemire's Blog
Do not waste time with STL vectors
I spend a lot of time with the C++ Standard Template Library. It is available on diverse platforms, it is fast and it is (relatively) easy to learn. It has been...
From Daniel Lemire's Blog
On the quality of academic software
Software is eating the world. Despite a poor year, Facebook has a market capitalization of $65 billion. This little company with barely 2000 developers is worth...
From Daniel Lemire's Blog
Data alignment for speed: myth or reality?
Compilers align data structures so that if you read an object using 4 bytes, its memory address is divisible by 4. There are two reasons for data alignment: Some...
From Daniel Lemire's Blog
Creating incentives for better science
Popper argued that science should be falsifiable. To determine truth, we simply try to disprove an hypothesis until we are exhausted. It is a nice theory, but actual...
From Daniel Lemire's Blog
Fast bitmap decoding
An old programming trick is to represent sets of integers as bitmaps. For example, the sequence of integers 1, 4, 6 becomes the number 0b1010010 in binary (or 82...
From Daniel Lemire's Blog
Summer reading recommendations
What came after by Sam Winston is an intriguing scifi novel. It describes a near-future dystopia where a handful of large corporations have taken over the USA....
From Daniel Lemire's Blog
Punk money: how you can print your own currency
We all want and need money. However, for many services, paying actual dollars is inefficient. The transaction costs are too high. So we need a system whereas perfect...
From Daniel Lemire's Blog
Computer scientists need to learn about significant digits
I probably spend too much time reviewing research papers. It makes me cranky. Nevertheless, one thing that has become absolutely clear to me is that computer scientists...
From Daniel Lemire's Blog
Let us abolish page limits in scientific publications
As scientists, we are often subjected to strict page limits. These limits made sense when articles were printed on expensive paper. They are now obsolete. But we...
From Daniel Lemire's Blog