Converting Binary Numbers and Positional Number Systems

In order to convert the binary number 110010101 to a decimal number a few simple steps need to be taken. The first is to count out the number of digits, in this case there is nine. Now assign the right most digit 2 to the power of 0, then the next 2 to the power of 1 and so on until the last digit which should be 2 to the power of 8. Next find the values of each power. After you do this add together all the values that represent a one in the binary number. Your decimal number should be 405.

Going the other way is just as easy. Starting with the number 529 divide by 2. If there is a remainder record it with a 1 if not a 0. Next take the quotient of 529/2 and divide that by 2 record either a 1 or zero in the same manner on the left side of the prevoious digit. Continue doing this until the quotient is zero. Your binary number should be 1000010001.

The differnce between a positional and non positional number system is that in a positional number system the value of each digit is determined by its position. Whereas in a non positional number system the position does not change the value. For example the number 981 and 198 are different numbers in a positional number system but would be the same number in a non positional number system. So with this both binary and decimal number systems are positional number systems.

Unix commands and Chapter 6 of Natural Born Cyborgs

After using Unix for the first time I learned that commands are very important. Unlike in Windows where you click everything, Unix you simply type a command and something happens. A few important commands in Unix include chsh, ls, cd and date. The chsh command allows you to change your shell or the unit that reads your commands and tells the computer what to do. The next command, ls, creates a list of the files and directories in a given directory. This is much like browsing through "My computer" in Windows where everything is listed from "My Documents" to drives. The third command, cd, is what allows you to change directories. For example you can change between the root of steel and your own directory with your own files. This would be similar to changing from "control panel" to "My Documents" in Windows. The last command is not as technical as the others but is still helpful none the less. The date command allows you to view the date and time by simply typing in date. The Windows equivalent of this would be to hover the mouse over the time on the tool bar. Unix is very unique to any other operating system that I have used it will take some time to get use to it.


Natural Born Cyborgs---Response

In this chapter there is much talk of networks, and electronic paths. The idea that people are able to leave such paths for others to follow is very helpful in producing efficient systems. The example about purchasing a CD from amazon.com displayed this concept very well. The web site uses information gathered from users purchases to help other users find what they are looking for easier. This not only makes shopping easier for the customer, but also allows for more sales for amazon. The same system of gathering information is used in search engines. If a page is more popular under a certain keyword than it will be listed closer to the top rather than the bottom. The concept of these electronic paths and networks helps tremendously with connecting people to what they want in a faster and more efficient manner.

Modeling the World

Upon reading the lecture note on the modeling lecture, the purpose of modeling is clearly stated. The purpose is to help sove problems and answer questions. The notes also mention the history of modeling and how it got its start back in the days of Aristotle. From there new techniques were formed to bring modeling to where it is today. Modeling is a useful tool that we will use for years to come.