ocw.mit.edu的 10 大竞争对手

edx.org

Find the online learning path for you, delivered by world-class institutions like Harvard, Google, Amazon, and more.

khanacademy.org

Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere.

math.stackexchange.com

Q&A for people studying math at any level and professionals in related fields

coursera.org

Earn a university-issued certificate from a top university. Gain the relevant skills and build unique portfolio that attract attention from recruiters and hiring managers. Learn online and earn valuable credentials from top universities like the University of Chicago and Rutgers University.

tutorial.math.lamar.edu

welcome to my math notes site. contained in this site are the notes (free and downloadable) that i use to teach algebra, calculus (i, ii and iii) as well as differential equations at lamar university. the notes contain the usual topics that are taught in those courses as well as a few extra topics that i decided to include just because i wanted to. there are also a set of practice problems, with full solutions, to all of the classes except differential equations. in addition there is also a selection of cheat sheets available for download.

arxiv.org

A system of non-tradable credits that flow between individuals like karma, hence proposed under that name, is a mechanism for repeated resource allocation that comes with attractive efficiency and fairness properties, in theory. In this study, we test karma in an online experiment in which human subjects repeatedly compete for a resource with time-varying and stochastic individual preferences or urgency to acquire the resource. We confirm that karma has significant and sustained welfare benefits even in a population with no prior training. We identify mechanism usage in contexts with sporadic high urgency, more so than with frequent moderate urgency, and implemented as a simple (binary) karma bidding scheme as particularly effective for welfare improvements: relatively larger aggregate efficiency gains are realized that are (almost) Pareto superior. These findings provide guidance for further testing and for future implementation plans of such mechanisms in the real world.

physics.stackexchange.com

Q&A for active researchers, academics and students of physics

math.libretexts.org

The LibreTexts libraries collectively are a multi-institutional collaborative venture to develop the next generation of open-access texts to improve postsecondary education.

mathworld.wolfram.com

A connected graph G is distance-regular if for any vertices x and y of G and any integers i,j=0, 1, ...d (where d is the graph diameter), the number of vertices at distance i from x and distance j from y depends only on i, j, and the graph distance between x and y, independently of the choice of x and y. In particular, a distance-regular graph is a graph for which there exist integers b_i,c_i,i=0,...,d such that for any two vertices x,y in G and distance i=d(x,y), there are exactly c_i...