Binary to Decimal and Decimal to Binary, and the difference between positional and non-positional

Binary to Decimal:

1. First write out the binary number and then put the power of 2's under that number in ascending order from left to right. For example: the binary number 1001001 on top and have the power of 2's under it like: 2^1, 2^2, ... and so on.
   

2. Then under every 1 that is in the number calculate what that power of two equals. For example: a 1 has 2^3 under it so it equals 8. Do not do anything to the zeros because they don't matter here.

3. Once you get all of the numbers calculated under the 1's spots add up those numbers to get that total, which equals that number in decimal.

So for the number given in class: 110010101 by doing this process you get 405 in decimal.

Decimal to Binary:

1. First write down the number in decimal. Next, find a power of 2 that does not exceed the number given in class, 529. For example the value of 2^9= 512 so it fits into your original number without exceeding it.
   
2. Once you do that you will get a remainder and you write that down up next to the original number to keep track of it. Next, you want to do the same thing that you did with your original number, find a power of 2 that fits into the remainder that you just got and write that power of 2 under the remainder.
   
3. You do this process until you get a remainder of 1, which will make the only power of 2 that will fit into it 2^0, which is 1.
   So the first number in the binary number is 1.
4. You then skip the power 2^4 since isn't a 1. So you go over past the second, third, and fourth spot. In the fifth place you put a 1. So the number so far would be 10001.
5. You continue like this for the last power of 2, which is 2^9. And then you go over the same amount of spaces left to right and the final number in binary is 100010001.

Positional Compared to Non-Positional Number Systems:

A non-positional number system is that which does not rely on the position of a digit in a number, but it uses symbols to tell what the values are. For example, if a square stood for ten and a circle stood for one-hundred. If there was a square in front of a circle it would be 110, if the two symbols were switched around and the circle was in front of the square, it would still equal the same number of 110, even though they were switched around.

A positional number system is the same number system that we use everyday. It means that the position of the digits tell the value of the number shown. For example if you had 345, it means three-hundred and forty five. If you were to switch the numbers around to make it look like 543, then the number would be five-hundred and forty three instead, because the position of the digits determines the value of the whole number unlike the symbols in the non-positional number system.

Global Swarming Response

In the article on Global Swarming, the beginning was very interesting on how he talked about how Amazon's website has the "viewers who bought this item also liked these items". It is interesting how Amazon uses its "collaborative filtering" to show buyers other items that are somewhat related to the item they are looking at. This technique helps the buyer find new or related music for example that they have never thought of buying. Another interesting aspect of the article was the idea of "swarm intelligence". It makes sense and is a very intersting idea to look at. It really has a lot to do with the collaborative filtering as talked about in the article earlier. I did not realize that the internet search engines used this collaborative filtering to come up with web pages. The chapter was very easy to understand and made a lot of good examples towards the subject of swarm intelligence. It made you think a lot of how the internet search engines work and get their information to the user on the web.

Important Unix Commands

There are many useful and important commands to use when using the OS Unix. Here are four of the most important ones that I thought were the most useful:

1. chsh- This is important because it will allow the user to change to a completely different schell to use instead of the one they are using.

2. ls- This command is very useful in that it shows all of the directories and files in a directory in a list that displays on the screen. It makes it easier to find the directories.

3. cd- This command allows the user to change to a different directory than that of the one they were on. It helps the user to move from one directory to another easier.

4. exit- This command is very simple in it's use, it simply logs or exits the user off of the remote system.

Modeling The World Response

I did not know that modeling was so complicated. I knew about the prediction part of the modeling process, but I did not know that the prediction is the most important part of the modeling process. It really determines how you are going to approach the experiment and how the process will work. The model sort of revolves around the prediction, according to the notes. I did not know that modeling served so many purposes such as: Data Analysis, interpretation, control, prediction,and understanding. The modeling strategies for dummies is a very good section in that it sure helps out people like me understand the steps of modeling easier.