Course
digital signal processing ppt:http://signal.ece.utexas.edu/~arslan/courses/dsp/
2. Solving optimization problems using Matlab optimization toolbox-tutorial: http://www.tu-ilmenau.de/fileadmin/media/simulation/Lehre/Vorlesungsskripte/Lecture_materials_Abebe/OptimizatioWithMatlab.pdf
3. A brief introduction to calculus of variations: http://wwwx.cs.unc.edu/~mn/classes/comp775/doc/calculusOfVariations.pdf
4. tutorial on convex optimization:http://galletue.ing-mat.udec.cl/~camilo/material_udec/icm/2011-1/Opti%20II/material%20web/CvxOptTutPaper.pdf
5. signal processing:https://ccrma.stanford.edu/~jos/
6. CourseRA 334 Course from 62 Universities: https://www.coursera.org/
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1. World first class including all subjects: https://www.khanacademy.org/about