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Comment KDE Kolab (Score 2) 133

I'm currently in the process of setting up something like this.
Kolab is a FOSS groupware server that can synchronize emails, to do lists, calenders, notes, etc. across multiple devices. You can access it from the included web interface (roundcube), the recommended client (Kontact), or via Outlook with the connector installed. Android support is available via ActiveSync, and I believe Kontact Touch will be ported to Android now that Qt 5 supports it.)

If you're not interested in running your own server, there're also sites like this which sell accounts.

Here are some notes on my experiences setting it up, for anyone interested:

  • Make sure you read the documentation first, because Kolab is too complex to just jump right in and hit the ground running. In particular, make sure you have a FQDN
  • Kolab pulls in a bunch of different daemons, including apache2, cyrus, mysql, postfix, slapd, clamav. It's a fairly heavy-weight solution, since it was developed with enterprise users in mind.
  • Multiple users can use a single installation. Users can be added/removed from a web interface.
  • By default, nothing uses SSL. This is undesirable if you're planning on connecting to it over the internet. The LDAP server uses a different SSL stack to the rest of the daemons (NSS), and you'll definitely want to run it over SSL because it sends passwords in plaintext. The easiest solution I found was to create a CA cert with certutil, use that to create the certificate for use with LDAP, then export that certificate to PEM format and use it for everything else. LDAP needs to be configured online, but all the other daemons just have configuration files with entries for the path to the certificates.
  • On some distros, Kontact may not be compiled with Kolab support. (e.g. Sabayon)
  • RSS syncing is currently the only feature in Kontact that doesn't sync with Kolab (AFAIK), although you can embed tt-rss in the web interface.

Comment Re:Is it a competitor? (Score 1) 166

How does Octave or any other open source tool hold up against something with so many resources behind it?

Background: I'm an ECSE student who has used both throughout my course.

Octave is very much like LibreOffice - it's usually good enough to use instead of MATLAB, but it's not perfect. Most of the functions are there, though some which are commonly used but not strictly necessary (e.g. importdata) are not. Octave's syntax is also looser than MATLAB's (you can use ! instead of ~ for logical negation), which means that you still need to test a program in MATLAB if that's what the recipient is going to be running it in.

Its main advantages are its cost and size - Octave is free and a full installation is 42 MB, whereas MATLAB costs tens of thousands and takes up about 5 GB. MATLAB also has rather cumbersome DRM that can cause issues.

The main disadvantage is speed. Running a SVD on a largish matrix (e.g. 350x350) is one or two orders of magnitude slower under Octave compared to MATLAB. i.e. it takes 10 min instead of 10 seconds. That's a pretty niche use though - most of the computations people use MATLAB for aren't particularly intensive.

Comment Re:A paranoid setup (Score 1) 321

Hardware RAID is a bad idea for backups, as the card is a single point of failure, and anything not from the exact same batch may use a different (proprietary) RAID format. At least with Linux softraid (either mdadm or btrfs/ZFS), you can always download a copy of the source and checkout the old version, if necessary.

Comment Re:Excellent question (Score 1) 321

Which version of the kernel and btrfs-progs are you using? Some distros are still shipping ancient versions of the userspace tools, like 0.19 or 0.20. The latest is 3.12 (they recently started using the kernel version instead), so you may want to try compiling it from the source.
The two most helpful commands I've found are 'mount -o recovery', which can restore the superblock if it's missing/corrupted, and 'btrfs check --repair' (formerly btrfsck). Note that check doesn't actually fix the errors it finds without that flag, unlike fsck. If you have a multi-device file system, trying to mount one of the other drives can help, since copies of the metadata are stored on all of them (RAID1 style).
If that doesn't work, you can often get the data off by mounting it as readonly, or by using 'btrfs restore'.

Btrfs used to be quite buggy, but these days I've found it to be pretty stable and reliable. That only applies if you're using the latest packages though - otherwise, you might as well be using it back in the early days.

Comment Re:Going to change everything (Score 1) 162

It's called a guaranteed minimum income.
What you are saying is minimum wage. The fancy term you have latched onto is 'minimum income' because 'minimum wage' has started to 'sound bad' and is 'demeaning'. As an aside I would ask you where did you pick up this term?

Minimum income is not the same as minimum wage. Minimum wage is the min. amount you can be paid (per hour) if you have a job. (Guaranteed) minimum income is the minimum amount each person receives each year, regardless of whether they have a job or not.

In the absence of min wage (which you seem to advocate), as robotic labour replaces human labour the supply will exceed demand, and wages will approach zero asymptotically. Below a certain point, people with jobs will not be able to sustain themselves, let alone those who are unemployed. GMI is one proposed solution to ensure that their basic requirements (food, water, shelter, etc.) are met.

Comment Re: Manjaro rolling release (Score 1) 346

Have you tried dealing with major transitions in a rolling release? e.g. sysvinit to systemd or upstart?

As a Sabayon user who just went through this, it was fairly trivial. `eselect sysvinit set systemd` to change, `eselect sysvinit set sysvinit` to change back.
SystemD is the default on new installs, but existing ones remain on OpenRC, which is still supported.

The trick to major transitions like these is to not force them; the users should have the choice to keep using the old version until it's unsupported. (It doesn't hurt that all major versions of most packages are still available in Portage.)

Comment Re:Mathematical explanation (Score 1) 1216

I've implemented the thought experiment above as an Octave script, if anyone feels like playing around with it.

function y = main()
        clc; clear; close all;
        gen = 20000; %no of iterations
        N = 50; %no of people
        limit = 12; %net worth cap is this times min net worth
        y = ones(N, gen);

        for i=2:gen
                y(:, i) = y(:, i-1);
                selection = select(y(:, i), i);
                %y(selection, i) = 1.01*y(selection, i);
                y(selection, i) = min(1.01*y(selection, i), limit*min(y(:, i)));
        end

        plot(y');
        grid on;

        y = y(:, gen);
end

function i = select(y)
        %selects an element from the vector y using proportional selection
        n = rand()*sum(y);
        count = 0;

        for i=1:length(y)
                count += y(i);

                if(n <= count)
                        return;
                end
        end

        i = length(y);
end

Comment Re:Can we get rid of the "grading on a curve", ple (Score 1) 204

Someone wrote that grading on a curve works in academia but not in industry. Why should it work for grading exams when it doesn't for ranking the workers? Especially the academics that are using it should know better.

The use of a curve in academia is more practical because the student's primary output is the grade, which is numeric. In contrast, the primary output of an employee is the work they do, which can only be (poorly) measured by metrics. Whether or not it's a good idea is a separate question though.

Finally, the second fallacy why this is fundamentally broken is the assumption that the skill distribution in a work team or class is normal (follows a bell curve). There is absolutely no guarantee of that, because, heck, you aren't hiring the idiots, are you? I am sure that the company is hiring only "rock star" developers. Same with the students - they have to pass stringent exams and fulfill admission criteria that the majority of the population isn't able. So you have a sample here that isn't representative of the entire population (where the bell curve would be valid) and all bets are off, because the system was built on an invalid assumption.
The most extreme example of this is the constant distribution - the case when all students turn in blank sheet of paper (identical "skill" level) for their exam and still pass. You would have to pick the students or hire employees randomly out of the entire population if you wanted to have a normal distribution of skill. Not very practical, though.

This isn't quite true, and seems to be based on the idea that people are reducible to one-dimensional numbers. Yes, the ability of the individuals (as measured by the admission/hiring process) will be a truncated bell curve (the highest N candidates from the applicant distribution). But the quality of the work done will be normally distributed, because there are countless other factors that contribute to the result. The only exception to this is when they operate collectively to alter the distribution, as in the example you gave above.

My opinion on the subject (as a student) is that relative grades are somewhat useful, since they help to normalize for the difficulty of different units, which would otherwise penalize students who took harder units. However, the scaling or change in grades should be monitored, since a change of more than 15% indicates something very wrong with the unit.

Perhaps more fundamental is the idea that the grade distribution should only be translated, not made to fit any particular distribution. This ensures that the average mark can be adjusted, while ensuring that the relative grades are retained.

Another line of thought is that scaling should only ever increase marks, not decrease them, so as to avoid demotivating students. Increasing the difficulty of the unit in future years is the preferable solution for that.

Comment Re:..and mouse scroll. (Score 1) 326

It's been a while, so I don't remember the full details, but I believe I did try this. IIRC, the issue was that I had a backup of everything except C:\Users from one installation, and backups of C:\Users from a different installation. Windows didn't like this because the SSIDs in the per-user registry hives were wrong. The only way that I was able to get it to work was completely deleting the accounts and recreating them, but that caused it to change the locations of the profiles (which was a problem since the Users folder was shared across the network and a bunch of stuff depended on it).

In the end I just got frustrated with trying to fix a system that Microsoft clearly didn't want me to understand, and gave up on getting the installation to work. Linux actually worked much better than I'd expected - Office worked almost flawlessly under Wine, most of my commonly used programs were cross platform anyway, and KDE is way more functional than the Windows desktop.

Comment Re:Gee, they're going to build an ARM-based comput (Score 4, Insightful) 176

A port expander is *not* the same thing as GPIOs - it means you incur the delays associated with doing things over USB/I2C/etc. Maybe that's ok if all you want to do is flash some LEDs or turn on a relay, but for timing constrained applications, that's not feasible.

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