How social media took us from Tahrir Square to Donald Trump - MIT Technology Review
To understand how digital technologies went from instruments for spreading democracy to weapons for attacking it, you have to look beyond the technologies themselves.
social-media  social-engineering  networks  public-policy  politics  political-economy 
3 days ago
[1808.03172] An Invitation to Noncommutative Algebra
This is a brief introduction to the world of Noncommutative Algebra aimed for advanced undergraduate and beginning graduate students.
mathematics  to-read  to-understand  group-theory  category-theory  introduction 
5 days ago
Figuring out when you can do a puzzle. – Occupy Math
This week’s Occupy Math looks at a type of puzzle where you want to fill a rectangle with a shape. We will be using the L-shaped 3-square polyomino, used to fill a 5×9 rectangle below, as our example shape. The goal is to figure out every possible size of rectangle that can be filled with this shape. If you are constructing puzzles for other people — e.g., your students — knowing which problems can be solved gives you an edge. The post will not only solve the problem for our example shape, but also give you tools for doing this for other shapes. The answers, and the tools, are at the bottom if you don’t feel like working through the reasoning.
mathematical-recreations  polyominoes  proof  rather-interesting  nudge-targets  consider:classification  consider:feature-discovery 
9 days ago
#QuarterTheCross Card Sort – Wonder in Mathematics
It is no secret that Quarter the Cross is one of my favourite tasks. I’ve written about it twice before: as a Day 1 activity and in connection with Fraction Talks. The original source is apparently T. Dekker & N. Querelle, 2002, Great Assessment Problems (www.fi.uu.nl/catch). It has proliferated in recent years, including with an active Twitter hashtag: #QuarterTheCross.
mathematical-recreations  nudge-targets  consider:novelty-search  innovation  to-write-about  learning-by-doing 
9 days ago
Custom Baking - Futility Closet
Is it possible to bake a cake that can be divided into four parts by a single straight cut?
mathematical-recreations  simplicity  nudge-targets  consider:looking-to-see  consider:novelty-search 
9 days ago
A Note about Cognitive Effort and Misinfo (Oh, and also I’m a Rita Allen Misinformation Solutions Forum Finalist) | Hapgood
I’m not necessarily sold on the Pennycook and Rand version of this idea, but I’m interested in the broader insight. I know it doesn’t explain the worst offenders, but I’ve found with those I work with that cynicism (“Pick what you want, it’s all bullshit!”) is often driven by the cognitive exhaustion of sorting through conflicting information. This insight also aligns with Hannah Arendt’s work — totalitarianism wins the information war by deliberately overwhelming the capacity of a population to reconcile endless contradictions. The contradictions are a tool to increase the cost of pursuing truth relative to other options.

If this is the case, one approach might be to encourage people to be more effortful when looking at online media. (Meh.) But the approach I favor is to reduce both the real and perceived cost of sorting through the muck through finding cheap, good enough methods and popularizing them. Doing that — while fostering a culture that values accuracy — might cause a few more people to regard the cost of checking something to be worth it relative to other seemingly more economical options like partisan heuristics, conspiracy thinking, or cynical nihilism.
cultural-dynamics  politics  reality-criticism  affordances  user-experience  social-psychology  argumentation  rather-interesting  to-write-about 
9 days ago
Laudator Temporis Acti: Shackled by a Certainty
Once someone is shackled by a certainty, he envies your vague opinions, your resistance to dogmas or slogans, your blissful incapacity to commit yourself. Blushing in secret for belonging to a sect or a party, ashamed of possessing a truth and of being enslaved by it, it is not his acknowledged enemies he resents, those who profess another, but you, the Indifferent, guilty of pursuing none. And if, in order to escape the servitude into which he has fallen, you seek refuge in vagueness or caprice, he will do everything in his power to forestall you, to hold you in a thrall analogous and, if possible, identical to his own.
epigrams  translation  to-write-about 
9 days ago
Institutional Cultures, Patents, and Open-Source Software for Open Access | Martin Paul Eve | Professor of Literature, Technology and Publishing
As you may know, the Centre for Technology and Publishing at Birkbeck publishes and maintains a piece of open-source software for journal publishing called Janeway. This software is licensed under the AGPLv3.

We chose this license for several reasons, but the most important was that we wanted strong CopyLeft protection, including for server-side usage, on this software. Other journal publishing software has been used extensively by for-profit third parties who refuse to contribute their modifications back into the open ecosystem. We do not wish to develop software that can be made subject to corporate, for-profit enclosure. Given recent acquisitions by Elsevier, this seems all the more important at this time. This seemed, to us, to offer the best deal for the community who pursue open access, as it is advocated for inside many academic libraries.
open-access  open-source  licensing  intellectual-property  cultural-norms  institutional-design  public-policy 
10 days ago
Bandit Algorithms
After nearly two years since starting to write the blog we have at last completed a first draft of the book, which is to be published by Cambridge University Press.
The book is available for free as a PDF and will remain so after publication. We’re grateful to Cambridge for allowing this.

Without further ado, here is the link.
probability-theory  online-learning  book  rather-interesting  to-read  algorithms  to-write-about 
10 days ago
[1806.07366] Neural Ordinary Differential Equations
We introduce a new family of deep neural network models. Instead of specifying a discrete sequence of hidden layers, we parameterize the derivative of the hidden state using a neural network. The output of the network is computed using a blackbox differential equation solver. These continuous-depth models have constant memory cost, adapt their evaluation strategy to each input, and can explicitly trade numerical precision for speed. We demonstrate these properties in continuous-depth residual networks and continuous-time latent variable models. We also construct continuous normalizing flows, a generative model that can train by maximum likelihood, without partitioning or ordering the data dimensions. For training, we show how to scalably backpropagate through any ODE solver, without access to its internal operations. This allows end-to-end training of ODEs within larger models.
neural-networks  machine-learning  representation  rather-interesting  deep-learning  to-understand  consider:representation  to-write-about 
10 days ago
Dembo , Peres : A Topological Criterion for Hypothesis Testing
A simple topological criterion is given for the existence of a sequence of tests for composite hypothesis testing problems, such that almost surely only finitely many errors are made.
via:cshalizi  statistics  learning-from-data  algorithms  existence-proof  consider:looking-to-see  to-write-about  nudge-targets 
11 days ago
A tale of three machines | The Math Less Traveled
The punchline is that this is not true!! That is,

It is possible to make working primality machines that truly do not know anything about any factors of .

Not only that, but we know how to make primality machines that run much faster than the fastest known factor machines!
number-theory  algorithms  rather-interesting  nudge-targets  proof  to-write-about 
12 days ago
The Fermat primality test | The Math Less Traveled
So this is better than nothing, but it’s not quite a primality machine, because it can’t tell us for sure that a number is prime. And it leaves a lot more questions: could we make big enough so that we could know for sure whether is prime? How big would have to be? What about for composite numbers; how fast do we expect this to be? Are there other ways to build on this basic idea to get better (faster, more certain) primality tests? I’ll write about all this and more in future posts!
number-theory  algorithms  rather-interesting  to-write-about  nudge-targets 
12 days ago
The logic of Buddhist philosophy goes beyond simple truth | Aeon Essays
One can hear similar sentiments, expressed with comparable ferocity, in many faculty common rooms today. Yet Western philosophers are slowly learning to outgrow their parochialism. And help is coming from a most unexpected direction: modern mathematical logic, not a field that is renowned for its tolerance of obscurity.
logic  history-of-science  representation  to-write-about  multivalued-logics 
13 days ago
A New Form of Association for the Internet Generation — part 2
How can we do things together that require money without having to worry about the complexity of creating and maintaining legal entities?
open-collective  to-read  to-understand  community-formation  organization 
21 days ago
About · Compositionality
Compositionality describes and quantifies how complex things can be assembled out of simpler parts. Compositionality, the journal, is a new open-access journal for research using compositional ideas, most notably of a category-theoretic origin, in any discipline. Topics may concern foundational structures, an organizing principle, or a powerful tool. Example areas include but are not limited to: computation, logic, physics, chemistry, engineering, linguistics, and cognition.
open-access  journals  publishing  nonprofit  rather-interesting  to-understand 
21 days ago
Theorem of the Day
The list is presented here in reverse chronological order, so that new additions will appear at the top. This is not the order in which the theorem of the day is picked which is more designed to mix up the different areas of mathematics and the level of abstractness or technicality involved. The way that the list of theorems is indexed is described here.
mathematics  proof  lists  rather-interesting  nudge-targets  consider:looking-to-see 
21 days ago
Julie d'Aubigny - Wikipedia
Julie d'Aubigny (1670/1673–1707), better known as Mademoiselle Maupin or La Maupin, was a 17th-century swordswoman and opera singer. Her tumultuous career and flamboyant life were the subject of gossip and colourful stories in her own time, and inspired numerous portrayals afterwards. Théophile Gautier loosely based the title character, Madeleine de Maupin, of his novel Mademoiselle de Maupin (1835) on her.
history  things-I-did't-know  via:twitter 
21 days ago
[1803.06610] Can You Pave the Plane Nicely with Identical Tiles
Every body knows that identical regular triangles or squares can tile the whole plane. Many people know that identical regular hexagons can tile the plane properly as well. In fact, even the bees know and use this fact! Is there any other convex domain which can tile the Euclidean plane? Yes, there is a long list of them! To find the list and to show the completeness of the list is a unique drama in mathematics, which has lasted for more than one century and the completeness of the list has been mistakenly announced not only once! Up to now, the list consists of triangles, quadrilaterals, three types of hexagons, and fifteen types of pentagons. In 2017, Michael Rao announced a computer proof for the completeness of the list. Meanwhile, Qi Yang and Chuanming Zong made a series of unexpected discoveries in multiple tilings in the Euclidean plane. For examples, besides parallelograms and centrally symmetric hexagons, there is no other convex domain which can form any two-, three- or four-fold translative tiling in the plane; there are only two types of octagons and one type of decagons which can form five-fold translative tilings.
tiling  mathematical-recreations  marjorie-rice  to-write-about  plane-geometry 
27 days ago
Color Problems: A Republished Tome Reveals the Color Wisdom and Poetics of 19th-Century Artist Emily Noyes Vanderpoel | Colossal
In 1901 artist and historian Emily Noyes Vanderpoel (1842-1939) published the painting manual Color Problems: A Practical Manual for the Lay Student of Color under the guise of flower painting and decorative arts, subjects that were appropriate for a woman of her time. The study provided an extensive look at color theory ideas of the early 20th-century. Her research-based techniques were later used and circulated by men without mention of her name, and are now commonly used in art curriculums. Many of the included studies predict design and art trends that wouldn’t occur for several decades, such as a concentric square format that predates Joseph Albers’s Homage to the Square by fifty years.
color  art-history  rather-interesting  to-read 
4 weeks ago
[1710.10964] At the Roots of Dictionary Compression: String Attractors
A well-known fact in the field of lossless text compression is that high-order entropy is a weak model when the input contains long repetitions. Motivated by this fact, decades of research have generated myriads of so-called dictionary compressors: algorithms able to reduce the text's size by exploiting its repetitiveness. Lempel-Ziv 77 is probably one of the most successful and known tools of this kind, followed by straight-line programs, run-length Burrows-Wheeler transform, and other less-known schemes. In this paper, we show that these techniques are different solutions to the same, elegant, combinatorial problem: to find a small set of positions capturing all distinct text's substrings. We call such a set a string attractor. We first show reductions between dictionary compressors and string attractors. This gives us the approximation ratios of dictionary compressors with respect to the smallest string attractor and allows us to solve several open problems related to the asymptotic relations between the output sizes of different dictionary compressors. We then show that the k-attractor problem - that is, deciding whether a text has a size-t set of positions capturing all substrings of length at most k - is NP-complete for k >= 3. We provide approximation techniques for the smallest k-attractor, show that the problem is APX-complete for constant k, and give strong inapproximability results. To conclude, we provide matching lower- and upper- bounds for the random access problem on string attractors. Our optimal data structure is universal: by our reductions to string attractors, it supports random access on any dictionary-compression scheme. In particular, our solution matches the lower bound also on LZ77, straight-line programs, collage systems, and macro schemes, and therefore essentially closes (at once) the random access problem for all these compressors.
compression  strings  feature-extraction  representation  algorithms  computational-complexity  to-understand  nudge-targets  consider:looking-to-see 
6 weeks ago
[1801.10139] Analysis of the Continued Logarithm Algorithm
The Continued Logarithm Algorithm - CL for short- introduced by Gosper in 1978 computes the gcd of two integers; it seems very efficient, as it only performs shifts and subtractions. Shallit has studied its worst-case complexity in 2016 and showed it to be linear. We here perform the average-case analysis of the algorithm: we study its main parameters (number of iterations, total number of shifts) and obtain precise asymptotics for their mean values. Our 'dynamical' analysis involves the dynamical system underlying the algorithm, that produces continued fraction expansions whose quotients are powers of 2. Even though this CL system has already been studied by Chan (around 2005), the presence of powers of 2 in the quotients ingrains into the central parameters a dyadic flavour that cannot be grasped solely by studying the CL system. We thus introduce a dyadic component and deal with a two-component system. With this new mixed system at hand, we then provide a complete average-case analysis of the CL algorithm, with explicit constants.
number-theory  numerical-methods  representation  computer-science  computational-complexity  rather-interesting  algorithms  continued-fractions  to-write-about 
6 weeks ago
[1710.00217] A Framework for Inferring Combination Lock Codes using Smartwatches
Wrist-wearables such as smartwatches and fitness bands are equipped with a variety of high-precision sensors that enable collection of rich contextual information related to the wearer and his/her surroundings and support a variety of novel context- and activity-based applications. The presence of such a diverse set of on-board sensors, however, also expose an additional attack surface which, if not adequately protected, could be potentially exploited to leak private user information. In this paper, we comprehensively investigate the feasibility of a new vulnerability that attempts to take advantage of a wrist-wearable's seemingly innocuous and poorly regulated motion sensors to infer a user's input on mechanical devices typically used to secure physical access, for example, combination locks. In this direction, we outline two motion-based inference frameworks: i) a deterministic attack framework that attempts to infer a lock's unlock combination from the wrist motion (specifically, angular displacement) data obtained from a wrist-wearable's gyroscope sensor, and ii) a probabilistic attack framework that extends the output of the deterministic framework to produce a ranked list of likely unlock combinations. Further, we conduct a thorough empirical evaluation of the proposed frameworks by employing unlocking-related motion data collected from human subject participants in a variety of controlled and realistic settings. Evaluation results from these experiments demonstrate that motion data from wrist-wearables can be effectively employed as an information side-channel to significantly reduce the unlock combination search-space of commonly-found combination locks, thus compromising the physical security provided by these locks.
security  inference  to-write-about  inverse-problems  rather-interesting  nudge-targets  feature-extraction 
6 weeks ago
[1803.08530] A Coloring Book Approach to Finding Coordination Sequences
An elementary method is described for finding the coordination sequences for a tiling, based on coloring the underlying graph. We illustrate the method by first applying it to the two kinds of vertices (tetravalent and trivalent) in the Cairo (or dual-3^ tiling. The coordination sequence for a tetravalent vertex turns out, surprisingly, to be 1, 4, 8 ,12, 16, ..., the same as for a vertex in the familiar square (or 4^4) tiling. We thought that such a simple fact should have a simple proof, and this article is the result. We also apply the method to obtain coordination sequences for the 3^,, 4.8^2, 3.12^2, and 3^4.6 uniform tilings, as well as the snub-632 and bew tilings. In several cases the results provide proofs for previously conjectured formulas.
combinatorics  feature-construction  representation  rather-interesting  enumeration  to-write-about  mathematical-recreations  consider:random-graphs  consider:non-tilings 
6 weeks ago
Harald Mante | Foto-Design

Freie und experimentelle Farbfotografie in Theorie und Praxis
Fotografie neu entdecken, vorhandenes Wissen vertiefen. Der Kurs steigert Ihre Sensibilität
im Bereich des Sehens und Entdeckens und gibt Anregungen für das Erarbeiten eigener Bilder. Gleichzeitig wächst das Vergnügen (oder der Ärger) bei der Betrachtung von Arbeiten anderer Fotografen, von Malern, Bildhauern und Architekten, aber auch Ihres alltäglichen Umfeldes.
Als Anfänger können Sie auch ohne Vorkenntnisse und mit einem einfachen Fotoapparat
teilnehmen. Lernen Sie die Welt neu zu sehen und entdecken Sie Ihre Kreativität!
Als schon aktiver Fotograf mit praktischen Vorkenntnissen können Sie Ihr vorhandenes
Wissen über die Prozesse der Wahrnehmung und die Anwendung der künstlerischen Mittel
vertiefen und für sich neue Motivwelten erschließen!
photography  life-goals 
7 weeks ago
[1806.00521] The lemniscate tree of a random polynomial
To each generic complex polynomial p(z) there is associated a labeled binary tree (here referred to as a "lemniscate tree") that encodes the topological type of the graph of |p(z)|. The branching structure of the lemniscate tree is determined by the configuration (i.e., arrangement in the plane) of the singular components of those level sets |p(z)|=t passing through a critical point.
In this paper, we address the question "How many branches appear in a typical lemniscate tree?" We answer this question first for a lemniscate tree sampled uniformly from the combinatorial class and second for the lemniscate tree arising from a random polynomial generated by i.i.d. zeros. From a more general perspective, these results take a first step toward a probabilistic treatment (within a specialized setting) of Arnold's program of enumerating algebraic Morse functions.
geometry  topology  rather-interesting  probability-theory  data-structures  feature-construction  to-understand  to-write-about 
7 weeks ago
[1806.10909] ResNet with one-neuron hidden layers is a Universal Approximator
We demonstrate that a very deep ResNet with stacked modules with one neuron per hidden layer and ReLU activation functions can uniformly approximate any Lebesgue integrable function in d dimensions, i.e. ℓ1(ℝd). Because of the identity mapping inherent to ResNets, our network has alternating layers of dimension one and d. This stands in sharp contrast to fully connected networks, which are not universal approximators if their width is the input dimension d [Lu et al, 2017]. Hence, our result implies an increase in representational power for narrow deep networks by the ResNet architecture.
representation  neural-networks  approximation  rather-interesting  to-write-about  to-do 
7 weeks ago
Journey of a Single Line – BLDGBLOG
“When he was eighty-five,” Sarah Cowan writes in a review of a show mounted by the Miguel Abreu Gallery in New York City, “Wacław Szpakowski wrote a treatise for a lifetime project that no one had known about. Titled ‘Rhythmical Lines,’ it describes a series of labyrinthine geometrical abstractions, each one produced from a single continuous line. He’d begun these drawings around 1900, when he was just seventeen—what started as sketches he then formalized, compiled, and made ever more intricate over the course of his life.”
abstraction  design  art  constraints  rather-interesting  to-write-about  consider:performance-measures 
7 weeks ago
Model of the motion of agents with memory based on the cellular automaton: International Journal of Parallel, Emergent and Distributed Systems: Vol 33, No 3
The article is devoted to the construction of the motion model for agents with memory. Agents can be interpreted, for example, as mobile robots or soldiers. Agents move on the landscape consisting of squares with different passability. The model is based on the cellular automaton with one common to all agents layer corresponding to the landscape and many agent-specific layers corresponding to an agent’s memory. Methods for the random landscape generation are developed. The dependence between configuration entropy of the landscape, efficiency of the path-finding algorithm based on the cellular automaton was found. Also, the dependence of the average speed of the agents’ motion on the landscape configuration entropy was shown.
cannot-read  what-was-that-dude's-name-at-Shippenssburg?  cellular-automata  artificial-life 
7 weeks ago
IASC: The Hedgehog Review - Volume 20, No. 1 (Spring 2018) - Digital Metaphysics: The Cybernetic Idealism of Warren McCulloch -
Kant famously stated that he had “awoken from his dogmatic slumber”30 by reading the Scottish Enlightenment philosopher David Hume. Hume maintained a bright line between “matters of fact” and “relations of ideas.” This meant that mental habit was central. If one wanted to form a meaningful sentence about the world (“this causes that”), then one would have to habituate the mind by noticing common correlations and regularly drawing the conclusion that one thing “caused” another. Kant disagreed. Cause, he reasoned, could not just be a mental habit, because it had a hidden premise: not that one thing followed another in time, but that it necessarily did so. To conceive of a necessity in the world was to add something more than habit to observation—to contribute a law to nature.
philosophy-of-science  philosophy  neural-networks  representation  cultural-assumptions  machine-learning  le-sigh  familiar-refrains-again-again 
7 weeks ago
[1705.04353] On the records
World record setting has long attracted public interest and scientific investigation. Extremal records summarize the limits of the space explored by a process, and the historical progression of a record sheds light on the underlying dynamics of the process. Existing analyses of prediction, statistical properties, and ultimate limits of record progressions have focused on particular domains. However, a broad perspective on how record progressions vary across different spheres of activity needs further development. Here we employ cross-cutting metrics to compare records across a variety of domains, including sports, games, biological evolution, and technological development. We find that these domains exhibit characteristic statistical signatures in terms of rates of improvement, "burstiness" of record-breaking time series, and the acceleration of the record breaking process. Specifically, sports and games exhibit the slowest rate of improvement and a wide range of rates of "burstiness." Technology improves at a much faster rate and, unlike other domains, tends to show acceleration in records. Many biological and technological processes are characterized by constant rates of improvement, showing less burstiness than sports and games. It is important to understand how these statistical properties of record progression emerge from the underlying dynamics. Towards this end, we conduct a detailed analysis of a particular record-setting event: elite marathon running. In this domain, we find that studying record-setting data alone can obscure many of the structural properties of the underlying process. The marathon study also illustrates how some of the standard statistical assumptions underlying record progression models may be inappropriate or commonly violated in real-world datasets.
extreme-values  time-series  feature-extraction  rather-interesting  dynamical-systems  to-understand 
8 weeks ago
[1805.07360] Prediction in Projection: A new paradigm in delay-coordinate reconstruction
Delay-coordinate embedding is a powerful, time-tested mathematical framework for reconstructing the dynamics of a system from a series of scalar observations. Most of the associated theory and heuristics are overly stringent for real-world data, however, and real-time use is out of the question due to the expert human intuition needed to use these heuristics correctly. The approach outlined in this thesis represents a paradigm shift away from that traditional approach. I argue that perfect reconstructions are not only unnecessary for the purposes of delay-coordinate based forecasting, but that they can often be less effective than reduced-order versions of those same models. I demonstrate this using a range of low- and high-dimensional dynamical systems, showing that forecast models that employ imperfect reconstructions of the dynamics---i.e., models that are not necessarily true embeddings---can produce surprisingly accurate predictions of the future state of these systems. I develop a theoretical framework for understanding why this is so. This framework, which combines information theory and computational topology, also allows one to quantify the amount of predictive structure in a given time series, and even to choose which forecast method will be the most effective for those data.
nonlinear-dynamics  representation  complexology  rather-interesting  to-write-about  to-understand 
8 weeks ago
[1806.01387] New And Surprising Ways to Be Mean. Adversarial NPCs with Coupled Empowerment Minimisation
Creating Non-Player Characters (NPCs) that can react robustly to unforeseen player behaviour or novel game content is difficult and time-consuming. This hinders the design of believable characters, and the inclusion of NPCs in games that rely heavily on procedural content generation. We have previously addressed this challenge by means of empowerment, a model of intrinsic motivation, and demonstrated how a coupled empowerment maximisation (CEM) policy can yield generic, companion-like behaviour. In this paper, we extend the CEM framework with a minimisation policy to give rise to adversarial behaviour. We conduct a qualitative, exploratory study in a dungeon-crawler game, demonstrating that CEM can exploit the affordances of different content facets in adaptive adversarial behaviour without modifications to the policy. Changes to the level design, underlying mechanics and our character's actions do not threaten our NPC's robustness, but yield new and surprising ways to be mean.
hey-I-know-this-guy  coevolution  evolutionary-algorithms  engineering-design  rather-interesting  to-write-about 
8 weeks ago
Symmathesy: A Word in Progress | norabateson
I would like to propose a new word for “System” that refers specifically to living systems – that is, to systems which emerge from the communications and interactions of living vitae (another new term, one which will be defined later). The new word, and concept, for “system” that I propose is one which highlights the expression and communication of interdependency and, particularly, mutual learning. The existing word, “system”, while useful for discussion of many kinds of systems, does not communicate contextual fields of simultaneous learning as is necessary for life. The inclusion of mutual learning in the terminology is specifically meant to preclude the models of engineering and mechanism that are implicit in much systems theorizing today.   We have learned that when dealing with living systems, the many variables of developing interaction become untenable to consider in such mechanistic parameters. This change in concept should spark a significant shift in our work, in the sciences, applied professions, communication, arts, that addresses or depends upon our understanding of life and evolution. The discourse with which we discuss and study the living world should be representative of the living world, and should cautiously avoid connotations that imply or are derived from engineering.

The notion of systems as being an arrangement of parts and wholes has become a distraction from the new systemic vision, which we are trying to encourage, that sees life as relational mutual learning contexts. As studies ranging from cognitive science to epigenetics, social science, ecology and evolutionary theory, are increasingly showing, evolution emerges in interrelationality, not in arrangement. Therefore the need is acute to create a differentiation between living systems and other systems.
complexology  representation  define-your-terms  rather-interesting  to-write-about  philosophy-of-science 
8 weeks ago
Philip Larkin, Programmer – Timothy – Medium
I make a sharp reply,
Then rebase my branch. I’m glad I can’t explain 
What insufficient docs their katas are; 
You may have thought things would come right again
If someone’d only merge your PR.
poems  in-the-style-of 
8 weeks ago
Kumaraswamy distribution: a beta-like probability density
Maybe the algorithm I suggested for picking parameters is not very good, but I suspect the optimal parameters are not much better. Rather than saying that the Kumaraswamy distribution approximates the beta distribution, I’d say that the Kumaraswamy distribution is capable of assuming roughly the same shapes as the beta distribution. If the only reason you’re using a beta distribution is to get a certain density shape, the Kumaraswamy distribution would be a reasonable alternative. But if you need to approximate a beta distribution closely, it may not work well enough.
probability-theory  representation  rather-interesting  to-write-about  consider:feature-discovery  consider:heuristics  consider:approximation 
8 weeks ago
[1805.11813] Derivatives of Turing machines in Linear Logic
We calculate denotations under the Sweedler semantics of the Ehrhard-Regnier derivatives of various encodings of Turing machines into linear logic. We show that these derivatives calculate the rate of change of probabilities naturally arising in the Sweedler semantics of linear logic proofs. The resulting theory is applied to the problem of synthesising Turing machines by gradient descent.
computer-science  representation  to-understand  rather-interesting 
8 weeks ago
[1805.10872] DeepProbLog: Neural Probabilistic Logic Programming
We introduce DeepProbLog, a probabilistic logic programming language that incorporates deep learning by means of neural predicates. We show how existing inference and learning techniques can be adapted for the new language. Our experiments demonstrate that DeepProbLog supports both symbolic and subsymbolic representations and inference, 1) program induction, 2) probabilistic (logic) programming, and 3) (deep) learning from examples. To the best of our knowledge, this work is the first to propose a framework where general-purpose neural networks and expressive probabilistic-logical modeling and reasoning are integrated in a way that exploits the full expressiveness and strengths of both worlds and can be trained end-to-end based on examples.
deep-learning  representation  probabilistic-programming  rather-interesting  to-understand 
9 weeks ago
[1806.02717] Gamorithm
Examining games from a fresh perspective we present the idea of game-inspired and game-based algorithms, dubbed "gamorithms".
hey-I-know-this-guy  machine-learning  philosophy-of-engineering  representation  to-write-about 
9 weeks ago
[1805.09966] Prestige drives epistemic inequality in the diffusion of scientific ideas
The spread of ideas in the scientific community is often viewed as a competition, in which good ideas spread further because of greater intrinsic fitness. As a result, it is commonly believed that publication venue and citation counts correlate with importance and impact. However, relatively little is known about how structural factors influence the spread of ideas, and specifically how where an idea originates can influence how it spreads. Here, we investigate the role of faculty hiring networks, which embody the set of researcher transitions from doctoral to faculty institutions, in shaping the spread of ideas in computer science, and the importance of where in the network an idea originates. We consider comprehensive data on the hiring events of 5,032 faculty at all 205 Ph.D.-granting departments of computer science in the U.S. and Canada, and on the timing and titles of 200,476 associated publications. Analyzing three popular research topics, we show empirically that faculty hiring plays a significant role in driving the spread of ideas across the community. We then use epidemic models to simulate the generic spread of research ideas and quantify the consequences of where an idea originates on its longterm diffusion across the network. We find that research from prestigious institutions spreads more quickly and completely than work of similar quality originating from less prestigious institutions. Our analyses establish the theoretical trade-offs between university prestige and the quality of ideas necessary for efficient circulation. These results suggest a lower bound for epistemic inequality, identify a mechanism for the persistent epistemic advantage observed for elite institutions, and highlight limitations for meritocratic ideals.
social-networks  citation  epidemiology-of-ideas  credentialing  who-reads-who  to-write-about  rather-interesting  academic-culture  meritocracy 
9 weeks ago
[1805.12244] Mining gold from implicit models to improve likelihood-free inference
Simulators often provide the best description of real-world phenomena; however, they also lead to challenging inverse problems because the density they implicitly define is often intractable. We present a new suite of simulation-based inference techniques that go beyond the traditional Approximate Bayesian Computation approach, which struggles in a high-dimensional setting, and extend methods that use surrogate models based on neural networks. We show that additional information, such as the joint likelihood ratio and the joint score, can often be extracted from simulators and used to augment the training data for these surrogate models. Finally, we demonstrate that these new techniques are more sample efficient and provide higher-fidelity inference than traditional methods.
machine-learning  simulation  representation  randomness  to-understand  to-write-about 
9 weeks ago
[1805.09460] Cautious Deep Learning
Most classifiers operate by selecting the maximum of an estimate of the conditional distribution p(y|x) where x stands for the features of the instance to be classified and y denotes its label. This often results in a hubristic bias: overconfidence in the assignment of a definite label. Usually, the observations are concentrated on a small volume but the classifier provides definite predictions for the entire space. We propose constructing conformal prediction sets [vovk2005algorithmic] which contain a set of labels rather than a single label. These conformal prediction sets contain the true label with probability 1−α. Our construction is based on p(x|y) rather than p(y|x) which results in a classifier that is very cautious: it outputs the null set - meaning `I don't know' --- when the object does not resemble the training examples. An important property of our approach is that classes can be added or removed without having to retrain the classifier. We demonstrate the performance on the ImageNet ILSVRC dataset using high dimensional features obtained from state of the art convolutional neural networks.
define-your-terms  representation  rather-interesting  machine-learning  conservative-estimates  performance-measure  to-write-about 
9 weeks ago
[1806.04510] Dank Learning: Generating Memes Using Deep Neural Networks
We introduce a novel meme generation system, which given any image can produce a humorous and relevant caption. Furthermore, the system can be conditioned on not only an image but also a user-defined label relating to the meme template, giving a handle to the user on meme content. The system uses a pretrained Inception-v3 network to return an image embedding which is passed to an attention-based deep-layer LSTM model producing the caption - inspired by the widely recognised Show and Tell Model. We implement a modified beam search to encourage diversity in the captions. We evaluate the quality of our model using perplexity and human assessment on both the quality of memes generated and whether they can be differentiated from real ones. Our model produces original memes that cannot on the whole be differentiated from real ones.
neural-networks  generative-art  generative-models  rather-interesting  amusing  to-write-about 
9 weeks ago
[1803.06824] Indeterminism in Physics, Classical Chaos and Bohmian Mechanics. Are Real Numbers Really Real?
It is usual to identify initial conditions of classical dynamical systems with mathematical real numbers. However, almost all real numbers contain an infinite amount of information. Since a finite volume of space can't contain more than a finite amount of information, I argue that the mathematical real numbers are not physically relevant. Moreover, a better terminology for the so-called real numbers is "random numbers", as their series of bits are truly random. I propose an alternative classical mechanics, which is empirically equivalent to classical mechanics, but uses only finite-information numbers. This alternative classical mechanics is non-deterministic, despite the use of deterministic equations, in a way similar to quantum theory. Interestingly, both alternative classical mechanics and quantum theories can be supplemented by additional variables in such a way that the supplemented theory is deterministic. Most physicists straightforwardly supplement classical theory with real numbers to which they attribute physical existence, while most physicists reject Bohmian mechanics as supplemented quantum theory, arguing that Bohmian positions have no physical reality. I argue that it is more economical and natural to accept non-determinism with potentialities as a real mode of existence, both for classical and quantum physics.
philosophy-of-science  mathematics  representation  rather-interesting  to-understand  information-theory  huh 
9 weeks ago
[1802.03905] How to Match when All Vertices Arrive Online
We introduce a fully online model of maximum cardinality matching in which all vertices arrive online. On the arrival of a vertex, its incident edges to previously-arrived vertices are revealed. Each vertex has a deadline that is after all its neighbors' arrivals. If a vertex remains unmatched until its deadline, the algorithm must then irrevocably either match it to an unmatched neighbor, or leave it unmatched. The model generalizes the existing one-sided online model and is motivated by applications including ride-sharing platforms, real-estate agency, etc.
We show that the Ranking algorithm by Karp et al. (STOC 1990) is 0.5211-competitive in our fully online model for general graphs. Our analysis brings a novel charging mechanic into the randomized primal dual technique by Devanur et al. (SODA 2013), allowing a vertex other than the two endpoints of a matched edge to share the gain. To our knowledge, this is the first analysis of Ranking that beats 0.5 on general graphs in an online matching problem, a first step towards solving the open problem by Karp et al. (STOC 1990) about the optimality of Ranking on general graphs. If the graph is bipartite, we show that the competitive ratio of Ranking is between 0.5541 and 0.5671. Finally, we prove that the fully online model is strictly harder than the previous model as no online algorithm can be 0.6317<1−1e-competitive in our model even for bipartite graphs.
algorithms  dynamical-systems  graph-theory  rather-interesting  computational-complexity  to-write-about  to-simulate 
9 weeks ago
Exploring the golden ratio Φ
This post is really just things I've learned from other people, but things that surprised me
mathematical-recreations  phi  geometry  to-write-about 
11 weeks ago
Home | Kappa Language
By separating a rule from a patch on which it acts we gain a much clearer approach to mechanistic causality. If causal analysis were to proceed at the level of patches, it would obfuscate the causal structure of a system by dragging along context irrelevant to an event. In addition to simulation and static analysis, the Kappa platform also extracts the causal structure of a rule system from its simulation traces.
bioinformatics  representation  hey-I-know-this-guy  complexology  pattern-discovery  rather-interesting  to-write-about 
11 weeks ago
Trent McConaghy - FFX
FFX is a technique for symbolic regression, to induce whitebox models given X/y training data. It does Fast Function Extraction. It is:

Fast - runtime 5-60 seconds, depending on problem size (1GHz cpu)
Scalable - 1000 input variables, no problem!
Deterministic - no need to "hope and pray".
If you ignore the whitebox-model aspect, FFX can be viewed as a regression tool. It's been used this way for thousands of industrial problems with 100K+ input variables. It can also be used as a classifier (FFXC), by wrapping the output with a logistic map. This has also been used successfully on thousands of industrial problems.
hey-I-know-this-guy  symbolic-regression  algorithms  numerical-methods  data-analysis  to-write-about 
11 weeks ago
Three Little Circles
Once upon a time, there were three little circles.
d3  tutorial  to-understand  javascript  visualization  for-a-project 
11 weeks ago
[1805.07980] Collisionless periodic orbits in the free-fall three-body problem
Although the free-fall three-body problem have been investigated for more than one century, however, only four collisionless periodic orbits have been found. In this paper, we report 234 collisionless periodic orbits of the free-fall three-body system with some mass ratios, including three known collisionless periodic orbits. Thus, 231 collisionless free-fall periodic orbits among them are entirely new. In theory, we can gain periodic orbits of the free-fall three-body system in arbitrary ratio of mass. Besides, it is found that, for a given ratio of masses of two bodies, there exists a generalized Kepler's third law for the periodic three-body system. All of these would enrich our knowledge and deepen our understanding about the famous three-body problem as a whole.
nonlinear-dynamics  stamp-collecting  rather-interesting  nudge-targets  consider:looking-to-see  consider:performance-measures 
11 weeks ago
[1805.02436] Combining Tools for Optimization and Analysis of Floating-Point Computations
Recent renewed interest in optimizing and analyzing floating-point programs has lead to a diverse array of new tools for numerical programs. These tools are often complementary, each focusing on a distinct aspect of numerical programming. Building reliable floating point applications typically requires addressing several of these aspects, which makes easy composition essential. This paper describes the composition of two recent floating-point tools: Herbie, which performs accuracy optimization, and Daisy, which performs accuracy verification. We find that the combination provides numerous benefits to users, such as being able to use Daisy to check whether Herbie's unsound optimizations improved the worst-case roundoff error, as well as benefits to tool authors, including uncovering a number of bugs in both tools. The combination also allowed us to compare the different program rewriting techniques implemented by these tools for the first time. The paper lays out a road map for combining other floating-point tools and for surmounting common challenges.
numerical-methods  algorithms  optimization  rather-interesting  floating-point  representation  to-understand  nudge-targets  consider:looking-to-see 
11 weeks ago
[1805.02213] Uniform Distribution of Kakutani Partitions Generated By Substitution Schemes
The main result of this paper is a proof of uniform distribution for a large family of sequences of partitions, constituting a generalization of a result of Kakutani regarding partitions of the unit interval. A sequence is defined according to a multiscale substitution scheme on a set of prototiles, which is a set of substitution rules determining a tiling of each prototile by rescaled copies of the prototiles at hand. Given a multiscale substitution scheme, a succession of substitutions of tiles is used to define a sequence of partitions, which is studied using a directed weighted graph associated with the scheme.
tiling  recursion  graph-theory  fractals  to-understand  rewriting-systems 
11 weeks ago
[1805.02274] On the $f$-Matrices of Pascal-like Triangles Defined by Riordan Arrays
We define and characterize the f-matrices associated to Pascal-like matrices that are defined by ordinary and exponential Riordan arrays. These generalize the face matrices of simplices and hypercubes. Their generating functions can be expressed simply in terms of continued fractions, which are shown to be transformations of the generating functions of the corresponding γ- and h-matrices.
combinatorics  continued-fractions  topology  to-understand  to-write-about  nudge-targets  consider:looking-to-see 
12 weeks ago
[1607.01117] Anagram-free Graph Colouring
An anagram is a word of the form WP where W is a non-empty word and P is a permutation of W. We study anagram-free graph colouring and give bounds on the chromatic number. Alon et al. (2002) asked whether anagram-free chromatic number is bounded by a function of the maximum degree. We answer this question in the negative by constructing graphs with maximum degree 3 and unbounded anagram-free chromatic number. We also prove upper and lower bounds on the anagram-free chromatic number of trees in terms of their radius and pathwidth. Finally, we explore extensions to edge colouring and k-anagram-free colouring.
graph-theory  algorithms  graph-coloring  feature-construction  nudge-targets  consider:looking-to-see  computational-complexity 
12 weeks ago
[1612.09443] Transversals in Latin arrays with many distinct symbols
An array is row-Latin if no symbol is repeated within any row. An array is Latin if it and its transpose are both row-Latin. A transversal in an n×n array is a selection of n different symbols from different rows and different columns. We prove that every n×n Latin array containing at least (2−2‾√)n2 distinct symbols has a transversal. Also, every n×n row-Latin array containing at least 14(5−5‾√)n2 distinct symbols has a transversal. Finally, we show by computation that every Latin array of order 7 has a transversal, and we describe all smaller Latin arrays that have no transversal.
combinatorics  existence-proof  rather-interesting  nudge-targets  consider:looking-to-see 
12 weeks ago
[1708.09571] Anagram-free colourings of graph subdivisions
An anagram is a word of the form WP where W is a non-empty word and P is a permutation of W. A vertex colouring of a graph is anagram-free if no subpath of the graph is an anagram. Anagram-free graph colouring was independently introduced by Kam\v{c}ev, {\L}uczak and Sudakov and ourselves. In this paper we introduce the study of anagram-free colourings of graph subdivisions. We show that every graph has an anagram-free 8-colourable subdivision. The number of division vertices per edge is exponential in the number of edges. For trees, we construct anagram-free 10-colourable subdivisions with fewer division vertices per edge. Conversely, we prove lower bounds, in terms of division vertices per edge, on the anagram-free chromatic number for subdivisions of the complete graph and subdivisions of complete trees of bounded degree.
combinatorics  graph-theory  graph-coloring  computational-complexity  rather-interesting  nudge-targets  consider:looking-to-see 
12 weeks ago
[1803.07694] Defective and Clustered Graph Colouring
Consider the following two ways to colour the vertices of a graph where the requirement that adjacent vertices get distinct colours is relaxed. A colouring has "defect" d if each monochromatic component has maximum degree at most d. A colouring has "clustering" c if each monochromatic component has at most c vertices. This paper surveys research on these types of colourings, where the first priority is to minimise the number of colours, with small defect or small clustering as a secondary goal. List colouring variants are also considered. The following graph classes are studied: outerplanar graphs, planar graphs, graphs embeddable in surfaces, graphs with given maximum degree, graphs with given maximum average degree, graphs excluding a given subgraph, graphs with linear crossing number, linklessly or knotlessly embeddable graphs, graphs with given Colin de Verdi\`ere parameter, graphs with given circumference, graphs excluding a fixed graph as an immersion, graphs with given thickness, graphs with given stack- or queue-number, graphs excluding Kt as a minor, graphs excluding Ks,t as a minor, and graphs excluding an arbitrary graph H as a minor. Several open problems are discussed.
combinatorics  graph-theory  algorithms  rather-interesting  computational-complexity  nudge-targets  consider:performance-measures 
12 weeks ago
[1805.02356] Multimodal Machine Translation with Reinforcement Learning
Multimodal machine translation is one of the applications that integrates computer vision and language processing. It is a unique task given that in the field of machine translation, many state-of-the-arts algorithms still only employ textual information. In this work, we explore the effectiveness of reinforcement learning in multimodal machine translation. We present a novel algorithm based on the Advantage Actor-Critic (A2C) algorithm that specifically cater to the multimodal machine translation task of the EMNLP 2018 Third Conference on Machine Translation (WMT18). We experiment our proposed algorithm on the Multi30K multilingual English-German image description dataset and the Flickr30K image entity dataset. Our model takes two channels of inputs, image and text, uses translation evaluation metrics as training rewards, and achieves better results than supervised learning MLE baseline models. Furthermore, we discuss the prospects and limitations of using reinforcement learning for machine translation. Our experiment results suggest a promising reinforcement learning solution to the general task of multimodal sequence to sequence learning.
natural-language-processing  machine-learning  multitask-learning  rather-interesting  algorithms  performance-measure  to-write-about 
12 weeks ago
With Great Power Comes Poor Latent Codes: Representation Learning in VAEs (Pt. 2)
A machine learning idea I find particularly compelling is that of embeddings, representations, encodings: all of these vector spaces that can seem nigh-on magical when you zoom in and see the ways that a web of concepts can be beautifully mapped into mathematical space. I’ve spent enough time in the weeds of parameter optimization and vector algebra to know that calling any aspect of machine learning “magical” is starry-eyed even as I say it, but: approaches like this are unavoidably tantalizing because they offer the possibility of finding some optimal representation of concepts, a “optimal mathematical language” with which we can feed all of the world’s information to our machines.
machine-learning  the-mangle-in-practice  neural-networks  representation  rather-interesting  to-write-about 
12 weeks ago
Foot-candles: the different paths to tech – Alice Goldfuss
The deeper you dive into programming, the more you will run into topics covered by CS degrees. This may make you feel extremely behind and out of your depth. When this happens, keep the following in mind:

Your lack of knowledge in these topics doesn’t negate the work you’ve already done.
You know things CS grads don’t.
It’s likely your understanding of the topic is fresher and more complete than a CS grad who hasn’t touched it in years.
Everyone learns things in different orders and at different times, including CS grads.
Some things you will never need to know.
imposter-syndrome  computer-science  system-of-professions  careering  worklife  self-definition  to-write-about 
12 weeks ago
Navigating with grid-like representations in artificial agents | DeepMind
Most animals, including humans, are able to flexibly navigate the world they live in – exploring new areas, returning quickly to remembered places, and taking shortcuts. Indeed, these abilities feel so easy and natural that it is not immediately obvious how complex the underlying processes really are. In contrast, spatial navigation remains a substantial challenge for artificial agents whose abilities are far outstripped by those of mammals.
ethology  experiment  artificial-life  neural-networks  to-write-about  consider:nudge  consider:pattern-libraries 
12 weeks ago
The Only Woman to Win the Nobel Prize in Economics Also Debunked the Orthodoxy - Evonomics
I mention Lloyd’s essay to illustrate how ridiculous yet persistent the misconceptions about the “tragedy” dynamic truly are. Commons scholar Lewis Hyde dryly notes, “Just as Hardin proposes a herdsman whose reason is unable to encompass the common good, so Lloyd supposes persons who have no way to speak with each other or make joint decisions. Both writers inject laissez-faire individualism into an old agrarian village and then gravely announce that the commons is dead. From the point of view of such a village, Lloyd’s assumptions are as crazy as asking us to ‘suppose a man to have a purse to which his left and right hand may freely resort, each unaware of the other’.”

This absurdity, unfortunately, is the basis for a large literature of “prisoner’s dilemma” experiments that purport to show how “rational individuals” behave when confronted with “social dilemmas,” such as how to allocate a limited resource. Should the “prisoner” cooperate with other potential claimants and share the limited rewards? Or should he or she defect by grabbing as much for himself as possible?
economics  ideology  public-policy  models-and-modes  commons  to-write-about  theory-and-practice-sitting-in-a-tree  libertarianism  assumptions 
may 2018
[1804.05445] Evolving Event-driven Programs with SignalGP
We present SignalGP, a new genetic programming (GP) technique designed to incorporate the event-driven programming paradigm into computational evolution's toolbox. Event-driven programming is a software design philosophy that simplifies the development of reactive programs by automatically triggering program modules (event-handlers) in response to external events, such as signals from the environment or messages from other programs. SignalGP incorporates these concepts by extending existing tag-based referencing techniques into an event-driven context. Both events and functions are labeled with evolvable tags; when an event occurs, the function with the closest matching tag is triggered. In this work, we apply SignalGP in the context of linear GP. We demonstrate the value of the event-driven paradigm using two distinct test problems (an environment coordination problem and a distributed leader election problem) by comparing SignalGP to variants that are otherwise identical, but must actively use sensors to process events or messages. In each of these problems, rapid interaction with the environment or other agents is critical for maximizing fitness. We also discuss ways in which SignalGP can be generalized beyond our linear GP implementation.
gptp  hey-I-know-this-guy  genetic-programming  representation  to-write-about 
may 2018
[1802.03676] Differentiable Dynamic Programming for Structured Prediction and Attention
Dynamic programming (DP) solves a variety of structured combinatorial problems by iteratively breaking them down into smaller subproblems. In spite of their versatility, DP algorithms are usually non-differentiable, which hampers their use as a layer in neural networks trained by backpropagation. To address this issue, we propose to smooth the max operator in the dynamic programming recursion, using a strongly convex regularizer. This allows to relax both the optimal value and solution of the original combinatorial problem, and turns a broad class of DP algorithms into differentiable operators. Theoretically, we provide a new probabilistic perspective on backpropagating through these DP operators, and relate them to inference in graphical models. We derive two particular instantiations of our framework, a smoothed Viterbi algorithm for sequence prediction and a smoothed DTW algorithm for time-series alignment. We showcase these instantiations on two structured prediction tasks and on structured and sparse attention for neural machine translation.
representation  time-series  numerical-methods  deep-learning  rather-interesting  nudge-targets  consider:representation 
may 2018
[1803.05859v3] Neural Network Quine
Self-replication is a key aspect of biological life that has been largely overlooked in Artificial Intelligence systems. Here we describe how to build and train self-replicating neural networks. The network replicates itself by learning to output its own weights. The network is designed using a loss function that can be optimized with either gradient-based or non-gradient-based methods. We also describe a method we call regeneration to train the network without explicit optimization, by injecting the network with predictions of its own parameters. The best solution for a self-replicating network was found by alternating between regeneration and optimization steps. Finally, we describe a design for a self-replicating neural network that can solve an auxiliary task such as MNIST image classification. We observe that there is a trade-off between the network's ability to classify images and its ability to replicate, but training is biased towards increasing its specialization at image classification at the expense of replication. This is analogous to the trade-off between reproduction and other tasks observed in nature. We suggest that a self-replication mechanism for artificial intelligence is useful because it introduces the possibility of continual improvement through natural selection.
artificial-life  machine-learning  quines  rather-interesting  to-write-about  hey-I-know-this-guy 
may 2018
DAVID GRAEBER / The Revolt of the Caring Classes / 2018 - YouTube
"The financialisation of major economies since the '80s has radically changed the terms for social movements everywhere. How does one organise workplaces, for example, in societies where up to 40% of the workforce believe their jobs should not exist? David Graeber makes the case that, slowly but surely, a new form of class politics is emerging, based around recognising the centrality of meaningful 'caring labour' in creating social value. He identifies a slowly emerging rebellion of the caring classes which potentially represents just as much of a threat to financial capitalism as earlier forms of proletarian struggle did to industrial capitalism.

David Graeber is Professor of Anthropology, London School of Economics and previously Assistant Professor and Associate Professor of Anthropology at Yale and Reader in Social Anthropology at Goldsmiths, University of London. His books include The Utopia of Rules: On Technology, Stupidity, and the Secret Joys of Bureaucracy (2015) Debt: The First 5000 Years (2011) and Fragments of an Anarchist Anthropology (2004). His activism includes protests against the 3rd Summit of the Americas in Quebec City in 2001, and the 2002 World Economic Forum in New York City. Graeber was a leading figure in the Occupy Wall Street movement, and is sometimes credited with having coined the slogan, 'We are the 99 percent'.

This lecture was given at the Collège de France on the 22nd March 2018."
have-watched  very-good  care  caring  teaching  nursing  economics  capitalism  labor  work  employment  compensation  resentment  bullshitjobs  finance  politics  policy  us  uk  workingclass  intellectuals  intellectualism  society  manufacturing  management  jobs  liberalism  values  benefits  nobility  truth  beauty  charity  nonprofit  highered  highereducation  activism  humanrights  os  occupywallstreet  opportunity  revolution  revolt  hollywood  military  misery  productivity  creation  creativity  maintenance  gender  production  reproduction  socialsciences  proletariat  wagelabor  wage  salaries  religion  belief  discipline  maintstreamleft  hospitals  freedom  play  teachers  parenting  mothers  education  learning  unions  consumption  anarchism  spontaneity  universalbasicincome  via:robertogreco 
may 2018
[1801.07155] Continued fractions and orderings on the Markov numbers
Markov numbers are integers that appear in the solution triples of the Diophantine equation, x2+y2+z2=3xyz, called the Markov equation. A classical topic in number theory, these numbers are related to many areas of mathematics such as combinatorics, hyperbolic geometry, approximation theory and cluster algebras.
There is a natural map from the rational numbers between zero and one to the Markov numbers. In this paper, we prove two conjectures seen in Martin Aigner's book, Markov's theorem and 100 years of the uniqueness conjecture, that determine an ordering on subsets of the Markov numbers based on their corresponding rational.
The proof uses the cluster algebra of the torus with one puncture and a resulting reformulation of the conjectures in terms of continued fractions. The key step is to analyze the difference in the numerator of a continued fraction when an operation is applied to its entries.
number-theory  continued-fractions  rather-interesting  to-write-about  consider:looking-to-see  consider:generalizations 
may 2018
[1803.08823] A high-bias, low-variance introduction to Machine Learning for physicists
Machine Learning (ML) is one of the most exciting and dynamic areas of modern research and application. The purpose of this review is to provide an introduction to the core concepts and tools of machine learning in a manner easily understood and intuitive to physicists. The review begins by covering fundamental concepts in ML and modern statistics such as the bias-variance tradeoff, overfitting, regularization, and generalization before moving on to more advanced topics in both supervised and unsupervised learning. Topics covered in the review include ensemble models, deep learning and neural networks, clustering and data visualization, energy-based models (including MaxEnt models and Restricted Boltzmann Machines), and variational methods. Throughout, we emphasize the many natural connections between ML and statistical physics. A notable aspect of the review is the use of Python notebooks to introduce modern ML/statistical packages to readers using physics-inspired datasets (the Ising Model and Monte-Carlo simulations of supersymmetric decays of proton-proton collisions). We conclude with an extended outlook discussing possible uses of machine learning for furthering our understanding of the physical world as well as open problems in ML where physicists maybe able to contribute. (Notebooks are available at this https URL )
rather-interesting  machine-learning  text  review 
may 2018
Agility should pay attention to Sociology – Romeu Moura – Medium
So I wrote myself a thread to explain 3 concepts from Bourdieu and their impact in Agility
sociology  agility  rather-good  to-write-about 
may 2018
The Artist Who Drew With Computers, Before Computers Were a Thing - SURFACE
“What makes Molnár’s work so important today is that her ability to experiment was aided and amplified by the tools she used,” say Anderson and Bianconi. “This spirit of experimentation allowed these works to be both systematic and humanistic, and has been influential for artists who have worked with computers since.”
generative-art  art-criticism  history  to-write-about  exhibition 
may 2018
The Metonymy of Matrices - Scientific American Blog Network
As a tool, the matrix is so powerful that it is easy to forget that it is a representation of a function, not a function itself. A matrix truly is just the array of numbers, but I think in this context, most mathematicians are metonymists. (Metonymers? Metonymnistes?) We think of the matrix as the function itself, and it’s easy to lose sight of the fact that it's only notation. Matrices don’t even have to encode linear transformations. They are used in other contexts in mathematics, too, and restricting our definition to linear transformations can shortchange the other applications (though for my money, the value of the matrix as a way of representing linear transformations dwarfs any other use they have).
matrices  representation  functions  mathematical-recreations  to-write-about 
may 2018
The Job Guarantee and the Wilted Liberal Imagination : Democracy Journal
"You can’t say this kind of public work and employment is impossible if you’re living in a society built by it."
economics  public-policy  labor  history-is-a-feature-not-a-bug 
may 2018
Orthogonal polygons | The Math Less Traveled
Quite a few commenters figured out what was going on, and mentioned several nice (equivalent) ways to think about it. Primarily, the idea is to draw all possible orthogonal polygons, that is, polygons with only right angles, organized by the total number of vertices. (So, for example, the picture above shows all orthogonal polygons with exactly ten vertices.) However, we have to be careful what we mean by the phrase “all possible”: there would be an infinite number of such polygons if we think about things like the precise lengths of edges. So we have to say when two polygons are considered the same, and when they are distinct. My rules are as follows:
mathematical-recreations  looking-to-see  geometry  polyominoes  to-write-about 
may 2018
Cooking the books – Almost looks like work
Since Christmas, at my house we’ve been cooking with 5 ingredients or fewer thanks to the acquisition of Jamie Oliver’s new book, the contents of which are mostly available online here. The recipes are unanimously very tasty, but that’s besides the point. The real mark of culinary excellence (in my humble opinion) is how efficiently one can buy ingredients to make as many of the recipes as possible in one shopping trip. Let’s investigate while the lamb is on.

Each of the 135 recipes in the book consists of 5 ingredients, some of which overlap. It is therefore not necessary to purchase 675 ingredients, there are actually only 239 unique ones. (Yes, I did spend a Sunday morning typing 675 individual ingredients into a spreadsheet.)

The question is then this:

In which order should I buy my ingredients to maximise the number of possible recipes as a function of number of ingredients?

Let’s start simply, and look at the frequency of occurrence of the ingredients.
mathematical-recreations  looking-to-see  cooking  data-analysis  leading-questions  rather-interesting 
may 2018
Props in Network Theory | Azimuth
We start with circuits made solely of ideal perfectly conductive wires. Then we consider circuits with passive linear components like resistors, capacitors and inductors. Finally we turn on the power and consider circuits that also have voltage and current sources.

And here’s the cool part: each kind of circuit corresponds to a prop that pure mathematicians would eventually invent on their own! So, what’s good for engineers is often mathematically natural too.
network-theory  abstraction  rather-interesting  models-and-modes  circles-and-arrows  bond-diagrams  to-write-about  to-understand  functional-programming  category-theory 
april 2018
Solved: A Decades-Old Ansel Adams Mystery - Atlas Obscura
WHEN YOU LOOK AT THE image above, what do you think of? Most will probably take in the beauty of its subjects, the mountain Denali and nearby Wonder Lake. A photographer might admire the skill of its creator, Ansel Adams. Adventurers may feel the urge to climb.

Donald Olson sees all that and something else: a mystery. He wants to know the moment it was taken. An astrophysicist and forensic astronomer, Olson uses quantitative methods to answer questions raised by artwork, literature, and historical accounts—not the heady ones, but the basic, surprisingly slippery who, what, when, and where.
photography  art-history  rather-interesting  inverse-problems  astronomy  via:kottke.org 
april 2018
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