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Showing posts from March 11, 2019

Application-level gateway

In the context of computer networking, an application-level gateway [1] (also known as ALG , application layer gateway , application gateway , application proxy , or application-level proxy [2] ) consists of a security component that augments a firewall or NAT employed in a computer network. It allows customized NAT traversal filters to be plugged into the gateway to support address and port translation for certain application layer "control/data" protocols such as FTP, BitTorrent, SIP, RTSP, file transfer in IM applications, etc. In order for these protocols to work through NAT or a firewall, either the application has to know about an address/port number combination that allows incoming packets, or the NAT has to monitor the control traffic and open up port mappings ( firewall pinhole ) dynamically as required. Legitimate application data can thus be passed through the security checks of the firewall or NAT that would have otherwise restricted the traffic for not meetin...

Big matrices in MATLAB

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0 Following my previous question in this post: I'm trying to build a 128 row matrix with N column (up to many millions). The sole purpose of this matrix is to calculate the mean or median of all 128 rows column wise and save it as a vector (same number of columns as my data). The size of my data files varies a lot and with smaller ones I've been able to perform just this without any issues using the code from the previous post (see above). But of course, if I'm dealing with bigger datasets I run out of memory. Keep in mind that the error is in concatenating the 128 rows into a new matrix. EDIT the code used for concatenating the data in the files is the following: for k = TTs; %TTs to plot cd (strcat('TT',num2str(k))); %TT folder for w = 1:4; load(strcat(...