A Conceptual Model for Communications Research Bruce H. Westley Malcolm S. MacLean Jr. Journalism Mass Communication Quarterly March 1957 vol. 34 no. 1 31-38 http://jmq.sagepub.com/content/34/1/31 Audiovisual communication review Winter 1955, Volume 3, Issue 1, pp 3-12 A conceptual model for communications research Bruce H. Westley, Malcolm S. MacLean http://link.springer.com/article/10.1007%2FBF02713344 非常感谢!
Sage is a free open-source mathematics software system licensed under the GPL. It combines the power of many existing open-source packages into a common Python-based interface. http://www.sagemath.org/ http://www.macresearch.org/plug-and-play-scientific-python-sage
SAGE 是一个新的开源数学软件,是基于浏览器的开源工具,由华盛顿大学开发。和Mathematica、Maxima等软件一样可以进行各种复杂的数学运算。SAGE系统基于Python语言,如果你曾经用过Python,使用SAGE会感觉格外顺手。软件支持多种操作系统Mac OS X,Windows、Linux等。不过遗憾的是,目前Windows下是基于vmware虚拟机的。 国外开发了很多年了,功能也很强大,可惜国内关注很少。从英文介绍可以看出是一款相当不错,而且是一款有创意的软件。 软件主页: http://www.sagemath.org/ 英文介绍: Sage is built out of nearly 100 open-source packages and features a unified interface. Sage can be used to study elementary and advanced, pure and applied mathematics. This includes a huge range of mathematics, including basic algebra, calculus, elementary to very advanced number theory, cryptography, numerical computation, commutative algebra, group theory, combinatorics, graph theory, exact linear algebra and much more. It combines various software packages and seamlessly integrates their functionality into a common experience. It is well-suited for education and research. The user interface is a notebook in a web browser or the command line. Using the notebook, Sage connects either locally to your own Sage installation or to a Sage server on the network. Inside the Sage notebook you can create embedded graphics, beautifully typeset mathematical expressions, add and delete input, and share your work across the network. The following showcase presents some of Sage's capabilities, screenshots and gives you an overall impression of what Sage is. The examples show the lines of code in Sage on the left side, accompanied by an explanation on the right. They only show the very basic concepts of how Sage works. Please refer to the documentation material for more detailed explanations or visit the library to see Sage in action. 参考资料: http://www.sagemath.org/tour.html http://xb9he.blogchina.com/blog/6599266.html