Both can be modeled as finding a path through a network. In the TSP the path is closed (return to the starting node) and must touch all the nodes in the network. The packet travel in the net is more of finding the "best" path (BP) between two network nodes (source and destination). The definition of "best" is somewhat elusive... (faster, touching less number of nodes, using less used links to minimize congestion,...). The TSP is a NP-hard problem regarding algorithmic complexity (I think...), the BP can usually be solved with dynamic programming (in practical cases) and thus is less costly than the TSP in terms of complexity.
But the routing problem (and large TSPs, also) is not solved to get the optimal solution, but instead to get an "enough good" solution, using algorithms which can run in reasonable time.
And the internet network is so dynamic that when the message "leaves" the source it is not known the path that it will follow to the destination. I think that in the relay nodes the pack is routed "just-in-time" using the info the node has about the traffic in available links...
I also took a course from Udacity: https://www.udacity.com/course/cs344
but this one I didn't finish, I've done perhaps 30% of it (I already had finished Coursera's). One of these days I'll go there to close matters:-)
The courses in Udacity are "always online", so anyone can register anytime and finish the course with his/hers own pace. Quizzes, exams and grading with certificate included have no fixed limits. On the other hand, the courses from Coursera have deadlines and run more or less in parallel with "snail" university schedules, with start and stop dates, with time limits in quizzes and exams, etc. (You can usually see videos, and do quizzes anytime after they end, but no certificates and grading AFAIK).
Both courses were good -- I recommend both, -- we did homeworks in Amazon's cloud transparently, and certainly both were "sponsored" by Nvidia, coz we learned only CUDA. (Perhaps there was a brief blah blah about competing alternatives.)
But from what I've seen, if someone is afraid from CUDA, then its better to run away very fast from alternatives (OpenCL):-)
I still run 3 Win2K machines, with 8 to 10 yrs old approximately, and for a few years I had a (free) Avira installed, until it stopped supporting Win2K and, more importantly, until the machines knelt down because of it. As time goes by, antivirus become fantastic CPU hogs.
Don't blame me for still using an unsupported OS. I'm not an IT pro but I'm proud of never having had to reinstall any OS (the only scar I have from virus attacks is a crippled Excel which was "quarantined" many years ago -- but I can live without Excel:-).
So a few years ago after trying a couple of free AVs, I found this reanimator thing -- http://greatis.com/security/reanimator.html -- and now it is what I use in all my PCs (even some newer ones with Win 7), helped by MS firewall and built-in security tools, and recommend it to family and friends. And it never let me down. But its not a real-time scanner/monitor: you can scan filesystem and memory for malware as with a regular AV, and I use it a lot to kill nasty startup processes that burn resources (Adobe and Java updaters, etc...). Reanimator's database and executable are updated very often. I don't even remember that it is there...
But, anyway, the most dangerous site I surf is Slashdot:-), so I don't need AV heavy stuff...
Reanimator is not heavy and works either a "fire extinguisher" if you suspect you are infected or as a scan tool. In a couple of minutes I teach people how to use it (anyone without severe age damage can learn) and it is effective. However, I do not have experience in dealing with elder retired people.
Regarding switching to Linux, it's a bad day to talk to me about it: my usual server (not maintained by me), an old PC built with "pro" material, which since a f
No I'm not. I'm just trying that one of the Vine reviewers which uses the sample copy of the book as a monitor stand offers to sell me the thing by 20 bucks, at most:-)
I spent a few minutes seeing the "portfolio" of some of the "Vine reviewers" of the book, and one of them (a male, if he's not faking) even had a review of a pack of tampons (yes!!! 4 stars, I think), although he really had the decency to warn that he was doing the review on behalf of a lady in his family (daughter, niece?).
"Hey Jane, are those Vine tampons I offered you comfortable? I need to write a review...":-)
Even if there are no "competitors" for this book, honest reviews can eventually help you in deciding to spend $127 or not. So, niche products deserve fair reviews despite not being best sellers.
That's not 100% true.
I just finished "Learning from data" offered online independently (of Coursera, Udacity,...) by Caltech, in concrete by Prof. Yaser Abu-Mostafa, who answered in person to most of the the questions promptly, in a couple of hours, even on Sundays. It was also true that the number of questions was not overwhelming, and usually were valid questions (I think stupid people didn't abound in the forum.)
I don't know how many people was in the class, but hundreds, probably.
BTW, a very nice class, I learned a lot, and it just started the fall run a few days ago. I Recommend wholeheartedly. And in video classes you can listen to the professor when you are in the mood and have spare time, not at a precise time spot as in "real" classes. This is a big plus IMHO.
Well, despite optimism about how the Japan officials are handling the failures at the reactors,
it seems a 3rd and more serious blast occurred in reactor II less than an hour from now...
It seems melting down is ongoing.
The issue here is that many things were overlooked, even if we take into account the huge magnitude of
the event. For instance, the massive anti-tsunami barriers in Japan coast were no effective at all. Also,
it seems many people didn't took the tsunami warning seriously and didn't go to high places. That is
one explanation for the probably serious death toll. More problems for engineers tackle in the next few years...
Google aggregation of news about the 3rd blast in this link:
http://www.google.com/#q=3rd+blast+fukushima&hl=en&prmd=ivnsu&source=univ&tbs=nws:1&tbo=u&sa=X&ei=W7N-TfbJIMGEOorbzesK&sqi=2&ved=0CDIQqAI&bav=on.2,or.r_gc.r_pw.&fp=9856b7f95556a9fa
Slashdot Mirror
Both can be modeled as finding a path through a network. In the TSP the path is closed (return to the starting node) and must touch all the nodes in the network. The packet travel in the net is more of finding the "best" path (BP) between two network nodes (source and destination). The definition of "best" is somewhat elusive... (faster, touching less number of nodes, using less used links to minimize congestion,...). The TSP is a NP-hard problem regarding algorithmic complexity (I think...), the BP can usually be solved with dynamic programming (in practical cases) and thus is less costly than the TSP in terms of complexity. But the routing problem (and large TSPs, also) is not solved to get the optimal solution, but instead to get an "enough good" solution, using algorithms which can run in reasonable time. And the internet network is so dynamic that when the message "leaves" the source it is not known the path that it will follow to the destination. I think that in the relay nodes the pack is routed "just-in-time" using the info the node has about the traffic in available links...
I took that course: https://www.coursera.org/course/hetero
:-)
:-)
I also took a course from Udacity: https://www.udacity.com/course/cs344 but this one I didn't finish, I've done perhaps 30% of it (I already had finished Coursera's). One of these days I'll go there to close matters
The courses in Udacity are "always online", so anyone can register anytime and finish the course with his/hers own pace. Quizzes, exams and grading with certificate included have no fixed limits. On the other hand, the courses from Coursera have deadlines and run more or less in parallel with "snail" university schedules, with start and stop dates, with time limits in quizzes and exams, etc. (You can usually see videos, and do quizzes anytime after they end, but no certificates and grading AFAIK).
Both courses were good -- I recommend both, -- we did homeworks in Amazon's cloud transparently, and certainly both were "sponsored" by Nvidia, coz we learned only CUDA. (Perhaps there was a brief blah blah about competing alternatives.)
But from what I've seen, if someone is afraid from CUDA, then its better to run away very fast from alternatives (OpenCL)
30 dollars? Awsome! Probably PP added another 100 bucks to that... :-)
I still run 3 Win2K machines, with 8 to 10 yrs old approximately, and for a few years I had a (free) Avira installed, until it stopped supporting Win2K and, more importantly, until the machines knelt down because of it. As time goes by, antivirus become fantastic CPU hogs.
:-).
:-), so I don't need AV heavy stuff ...
Don't blame me for still using an unsupported OS. I'm not an IT pro but I'm proud of never having had to reinstall any OS (the only scar I have from virus attacks is a crippled Excel which was "quarantined" many years ago -- but I can live without Excel
So a few years ago after trying a couple of free AVs, I found this reanimator thing -- http://greatis.com/security/reanimator.html -- and now it is what I use in all my PCs (even some newer ones with Win 7), helped by MS firewall and built-in security tools, and recommend it to family and friends. And it never let me down. But its not a real-time scanner/monitor: you can scan filesystem and memory for malware as with a regular AV, and I use it a lot to kill nasty startup processes that burn resources (Adobe and Java updaters, etc...). Reanimator's database and executable are updated very often. I don't even remember that it is there...
But, anyway, the most dangerous site I surf is Slashdot
Reanimator is not heavy and works either a "fire extinguisher" if you suspect you are infected or as a scan tool. In a couple of minutes I teach people how to use it (anyone without severe age damage can learn) and it is effective. However, I do not have experience in dealing with elder retired people.
Regarding switching to Linux, it's a bad day to talk to me about it: my usual server (not maintained by me), an old PC built with "pro" material, which since a f
No I'm not. I'm just trying that one of the Vine reviewers which uses the sample copy of the book as a monitor stand offers to sell me the thing by 20 bucks, at most :-)
I spent a few minutes seeing the "portfolio" of some of the "Vine reviewers" of the book, and one of them (a male, if he's not faking) even had a review of a pack of tampons (yes!!! 4 stars, I think), although he really had the decency to warn that he was doing the review on behalf of a lady in his family (daughter, niece?).
:-)
"Hey Jane, are those Vine tampons I offered you comfortable? I need to write a review..."
Even if there are no "competitors" for this book, honest reviews can eventually help you in deciding to spend $127 or not. So, niche products deserve fair reviews despite not being best sellers.
That's not 100% true. I just finished "Learning from data" offered online independently (of Coursera, Udacity,...) by Caltech, in concrete by Prof. Yaser Abu-Mostafa, who answered in person to most of the the questions promptly, in a couple of hours, even on Sundays. It was also true that the number of questions was not overwhelming, and usually were valid questions (I think stupid people didn't abound in the forum.) I don't know how many people was in the class, but hundreds, probably. BTW, a very nice class, I learned a lot, and it just started the fall run a few days ago. I Recommend wholeheartedly. And in video classes you can listen to the professor when you are in the mood and have spare time, not at a precise time spot as in "real" classes. This is a big plus IMHO.
Well, despite optimism about how the Japan officials are handling the failures at the reactors, it seems a 3rd and more serious blast occurred in reactor II less than an hour from now... It seems melting down is ongoing. The issue here is that many things were overlooked, even if we take into account the huge magnitude of the event. For instance, the massive anti-tsunami barriers in Japan coast were no effective at all. Also, it seems many people didn't took the tsunami warning seriously and didn't go to high places. That is one explanation for the probably serious death toll. More problems for engineers tackle in the next few years... Google aggregation of news about the 3rd blast in this link: http://www.google.com/#q=3rd+blast+fukushima&hl=en&prmd=ivnsu&source=univ&tbs=nws:1&tbo=u&sa=X&ei=W7N-TfbJIMGEOorbzesK&sqi=2&ved=0CDIQqAI&bav=on.2,or.r_gc.r_pw.&fp=9856b7f95556a9fa