Lab 6

BINARY CONVERSIONS!!!!!!!!!!!!!

This might just be the greatest point in my life as a nerd. But it is sort of interesting.... alright here is a crash course in converting binary to decimal and the other way around.

1. convert 110010101 to decimal form.
first what i would do would be map out a table with 2 rows and a column for every number in the binary code. The top row would be the binary numbers, and the bottom row would be the factors of 2 corresponding to the number of ones in the code. Sort of like this....

1	1	0	0	1	0	1	0
2^7	2^6	2^5	2^4	2^3	2^2	2^1	2^0

Now, forget the columns that have zero in them completely. For every column that has a one, calculate the factor of two that corresponds to it. Then add all of the added up factors of two, so you get something like this.

1	1	0	0	1	0	1	0
128	64	0	0	8	0	2	0

The final step to converting the binary to decimal is adding up the bottom row.
128 + 64 + 0 + 0 + 8 + 0 + 2 + 0 =
202!!
simple right!
Now lets go in the opposite direction.

1000010001

To convert from decimal to binary, there are just a few simple steps.
First, divide the number by 2, and keep the remainder separate from the answer, so you do not get a decimal.
Next, repeat the first step again until you reach the number 1.
Last, when you have reached one, just place 1 in front of the binary number, and put all the remainders together and this will be your string of binary numbers.

to see this process view the below steps.

529/2= 264 remainder 1 ........ 1
264/2= 132 remainder 0 ........01
132/2= 66 remainder 0.......... 001
66/2= 33 remainder 0............0001
33/2=16 remainder 1.............10001
16/2=8 remainder 0...............010001
8/2=4 remainder 0................0010001
4/2= 2 remainder 0...............00010001
2/2= 1 remainder 0..............000010001
1/2= 0 remainder 1..............1000010001
so the binary code is 1000010001

Positional Vs. Non-positional Number Systems
The difference between positional and non-positional number systems is simple. A positional number system is based on where exactly the numbers lie in the sequence of numbers. A positional system needs a base (n) which each number on the line relates to based on its position. Numbers on the left are equal to the value of the numbers to the right of them times n. Inversely, the numbers to the right are equal to the numbers to the left of them divided by n.

A non-positional number system is not based on the physical position of numbers. For example the Roman Numeral number system is based on a symbol that changes according to the amount of the number.

Lab 5 cont.

Andy Clark's Chapter 6-"Global Warming"
This chapter was a very interesting chapter that had a lot to do with trends and how animals, humans, and computers follow different trends to collaborate systems of efficient life. Clark uses the the idea of "positive feedback" similar to how ants use pheromones to create paths to the closest food source. When the food source runs out, the path to the next closest food source will then have the most pheromones. The same concept applies for how the internet websites such as amazon.com market their products sold. They use a method called "collaborative filtering." This filtering notes what people buy and compare to other people that buy similar things. To me, it is sort of like the website creates a proposed "shopping list" for each shopper. It will give a list of things which other people purchased along with the item you are interested in. This system is interesting but has an obvious flaw. All people are different, and not everyone likes the same things, but it is useful because it is all based on trends.

Another key part of this chapter was the advancement of search engines. In the older days of search engines such as yahoo or infoseek, searches were based on text. These searches were very inaccurate in terms of what we have now. Search engines today have a more powerful way to search. These searches are based on hypertext and links. This strategy is similar to the pheromones of the ants and amazon.com. With this technology mastered every person could potentially have a special "list" of different websites that the computer would have previously planned for your to visit.

All in all, this chapter explains a lot of how searches are done, and how simple and natural searches can be. The technology is in our hands we as humans just have to work hard and think uniquely to come up with the most efficient and powerful search tool that can become an everyday tool in our lives.

Lab 5 Post

Unix commands.
1. The Unix command cal allows for you to see the calendar of a specific month out of a specific year depending on what you type in. In windows the equivalent to cal is just going to date and time on the task bar and right clicking the clock and going to date and time.
2. The Unix command ls is a command that allows you to see what files are in your current directory. The equivalent command in windows is just bringing up a folder and viewing the files on it, because windows is a gui it is much more simple to see what is there.
3. The Unix command cd is a command that allows for you to change directory, in windows it is the same thing as just going to my computer and selecting a new folder, and in dos it is the same thing as using the dir command.
4. The Unix command mkdir stands for make directory. This creates a new directory similar to how in windows you use the new folder function.

Lab 4 Post

Modeling the World

The world is full of "agents" who are informed by "signs" about certain "things." This is the basic principle discussed in the modeling the world lecture. Signs are everywhere in the world, and are part of the human, every-day life. In fact in my opinion, humans need signs to get through each and every day, and it is our benefit to have signs that help us react to different circumstances. The lecture notes state that a model is "any complete and consistent set of verbal arguments, mathematical equations, or computational rules which is thought to correspond to some other entity, its prototype." The prototype being anything in our world, conceptual or physical. Models are used to explain different things for different circumstances as signs are just representations. Models are used in our world to simplify the vast complexity of life on the planet earth. I guess it is hard to grasp everything that goes on, but modeling is used all over. Some basic examples are weather patterns, such as temperature, pressure, climate trends and things like that. I'm sure reading more into the process of modeling would help, and I am also sure that modeling is not as hard and complex as it seems.

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