Chit-chat

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Highly disappointed about: http://arstechnica.com/tech-policy/2014/05/oracles-java-api-code-protected-by-copyright-appeals-court-rules/

Sometimes I wonder if arstechnica is a subsidiary of the government and big business from the stories they publish.

Someone mentioned that the freedom of linux was in the number of distros. Kind of disagreed with that.  Been using linux since the 1990’s. At home was completely linux about seven years ago after I left my Microsoft based job. Certainly there are plenty of distros, but I think the real freedom is in the variety of application packages and the source code to choose from or not to choose from. Because you have the source code, you can modify not or not modify your system(s) to your whims.. For example, with proprietary software you have globs that per se are functionally separate. I.e. server, desktop, or etc.  With linux as well as bsd, you can morph to be a server desktop, or whatever. you choose. Lastly, you are not limited to hardware platforms. I use or have used linux on x86,  arm,  x86-64, ppc, and etc.  Bsd will run on almost anything. Even run it on my sega dreamcast,, Now that is freedom.

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Statistics are so interesting. I was curious about the NFL draft. Thinking how could I look at the results of the draft. Viola a spreadsheet of course. A spreadsheet is sometimes known as a flat file and looks much like an accountant;s worksheet. That is it has no relation to any other file in its most rudimentary form. For our purposes that would be just fine.The original list was in the order of when someone was drafted.

So I gathered the data from the draft with everything in corresponding columns. That makes sense. Then I thought what can I do. Arranging or sorting a list is one of the pluses of the spreadsheet. Let’s see you have the team name, draftee and his position, plus some other vital data. Posed myself a question that maybe opposing teams might ask. The teams obviously drafted where they thought they might need help. Lets do a sort and see who needs what. Instructions to do a sort for your spreadsheet may vary.

Noticed that there was only one punter drafted. Is that not cool? Feel like a NFL manager for a second.

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Every program should have at least these two points: start and stop. A program is like a todo list. You could use English, Spanish, or a host of other languages to use your todo list. More on logic steps later.

So with computer languages you can do the same thing.  Examples:

in C
#include <stdio.h>

main()
{
}

or

In basic:

rem start
rem stop

Of course that does not really do anything in that sequence. Now let’s go to the beginner’s hello world example and see how things change. Yes we are adding a step here in the sequence. Let’s just use english for now.

Examples:

in C

#include <stdio.h>

main()
{
printf(“Hello, world.\n”);
}

In Basic

rem start
print “Hello, world.”
rem stop
end

You can not get any simpler than that for a start, In some ways you are an architect putting rooms together for a house such as a bedroom, bathroom, kitchen, den, living room or etc. With logic you can have loops (repetitive actions), Decision structures (if
this happens then do one or more things, or else just do something else),  or just a sequence of steps. More on all of this later.

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We spend so much time worrying about wireless networking we forget to also consider what might be attached to the wired network. What is hidden behind the wall?

Actually I built a network tap for administrative purposes, but it shows how easily something like this could be hidden in the wall behind the sheetrock. Does not hurt to pull the screws once in a while to see what is there.

http://www.instructables.com/id/Passive-network-tap-revised/

Connected to the passive tap also could be a wireless device which makes for real security problems such as loss of company secrets and other financial data.

Screenshot - 05142014 - 09:02:17 AM

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Playing with OTA tv antennas again.. Took an aluminium plate and cut it to roughly the dimensions of the $49 commercial antenna. If I had not been in a hurry, the antenna would have looked nicer. Without resetting the channels on the receiver still was able to access over 80 tv stations. Not bad for a $3 investment.

 Update: Another antenna comparison. No CBS affiliate either.  Amazon wanted $99.

Again only a $3  investment for me.

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Using mathematics or what people have used mathematics for can be fun. One such item is a parabola. It can be used for everything from capturing radio waves to sound. There are a zillion formulas for building a parabola. One such formula is y=x^2/(4+b). But then, if you look closely on the net, there are examples you can use without all the math. In one article, I found a small picture of a parabola form that did not seem useful.

Then I thought to myself, what if I enlarged the picture, could the picture be more useful? Saving the picture to storage was the first task. Then we loaded the picture into a viewing program. There you could enlarge the picture and save it in the expanded format.

So far so good. Then I printed out the picture. Still do not have a parabola yet. Then it was time to get out the scissors and cut between the splines. Easy enough. Now just one last step in that we need to attach the splines together. Cellophane tape makes that easy.

SUNP0041

Then I thought, what about an even larger parabola. Poster size maybe. Extend out the spline edges with a straight edge (not like the crude extensions in the picture).

The we could make an even larger parabola all based on the original tiny picture. Let you do that your self. Let’s see solar cooker, sound umbrella, hat, or etc etc.

Update: Even larger parabola.

x y
0 0.0000
3 0.1875
6 0.7500
9 1.6875
12 3.0000
15 4.6875
18 6.7500
21 9.1875
24 12.0000
27 15.1875
30 18.7500
33 22.6875
36 27.0000
39 31.6875
42 36.7500
45 42.1875
48 48.0000
The formula for a parabola is:

y = x² ÷ (4 × p)

where p is the distance from the bottom of the parabola to the focal point, and x and y are cartesian coordinates of points along the parabola.

For a parabola that is to be 96 inches across (that is, -48 inches to +48 inches relative to the focal point) and 48 inches deep, with a focal point 12 inches above the bottom of the parabola, the formula generates the numbers shown in the table on the right.

Sometimes it is useful to be able to locate the focal point after the fact. Rearranging the above formula

p = x² ÷ (4 × y)

where x is the width (from the focal point) of the parabola, y is the depth of the parabola, and f is the distance ahead of the bottom of the parabola of the focal point. For our above 96 inch wide and 48 inch deep parabola, f solves to 12 inches.

SUNP0043
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A one day fast every once in a while does not hurt.

SUNP0038

Good day.

 

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