# June, 2015

## 美高中上演毕业快闪《Shake It Off》 现场气氛超嗨

【环球网综合报道】据英国《每日邮报》6月17日报道，美国新罕布什尔州朴茨茅斯一所高中的毕业生以创意快闪在当天的毕业典礼上惊艳四座，235名毕业生们随着泰勒·斯威夫特的热门单曲《Shake It ......

## 美科学家发现亮度超太阳300万亿倍星系

2 网易科技讯 5月22日消息，据美国媒体报道，科学家们使用NASA（美国宇航局）广域红外巡天探测卫星（WISE）的数据，发现了一个亮度超过太阳300万亿倍的遥远星系。这是迄今为止人类发现的亮度......

## 教育｜中国式批评不一定不好，美国式表扬也有问题

随着赵薇主演的电视剧《虎妈猫爸》热播，中国教育模式又一次引发话题。6月18日，美国加州大学河滨分校学校心理学专业助理教授王慈欣接受澎湃新闻专访，阐释她眼中的中美校园及家庭教育差异。......

## An Introduction to Gradient Descent and Linear Regression

http://spin.atomicobject.com/2014/06/24/gradient-descent-linear-regression/ Gradient descent is one of those “greatest hits” algorithms that can offer a new perspective for solving problems. Unfortunately, it’s rarely taught in undergraduate computer science programs. In this post I’ll give an introduction to the gradient descent algorithm, and walk through an example that demonstrates how gradient descent can be used to solve machine learning problems such as linear regression. At a theoretical level, gradient descent is an algorithm that minimizes functions. Given a function defined by a set of parameters, gradient descent starts with an initial set ofRead More

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## Tip: Using surf and meshgrid to create surface plots

https://www.cac.cornell.edu/vw/matlab/tips7.aspx To complement its two-dimensional line plots, MATLAB also provides the ‘surf’ function for making three-dimensional (surface) plots. Plots of this sort are useful in many areas of science and engineering, in particular for making diagrams and teaching simple concepts in optimization and vector calculus. Unfortunately, creating surface plots has not always been completely straightforward in MATLAB, and actually required the helper function ‘meshgrid’ in order to work correctly. Newer versions have ameliorated some of this difficulty by accepting vector input arguments, but here we will describe the “classic” wayRead More

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