Week 4 - Clear

This week's topic included "Application Software" and "Multimedia". I love listening to music as this is simply making my day a lot better. Thus I have loads of MP3s on my computer that I can choose from. However, I can still remember the times, when I sat in front of our radio, waiting for the right song to then tape it and have it on my own cassette to be able to play it whenever I want to. Today, I simply go to the iTunes store on the Internet, choose the music I heard in the radio or somewhere else, click on it, purchase and download it and then finally, I have it on my MacBook and can listen to it whenever and wherever I want to. This technology of MP3 is amazing and thus I think it is worth being talked about a bit more.

MP3 stands for "MPEG-1 Audio Layer 3". "MPEG" is simply short for the "Motion Pictures Expert Group", which is a group of people from the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Their mission is to "create and publish standards for various areas of technology", where MPEG specifically refers to "standards in audio and video formats used online, in TV broadcasts and DVD media". MP3 is an audio file format that has been compressed and can hence be distributed in smaller-sized files. These MP3 files can be up to 90% smaller than the original files. However, one has to be careful, to not compress the original audio file too much, as this technique is a lossy compression method. It is taking advantage of the "auditory masking" effect, which means that the human hearing system cannot hear certain tones, when other sounds share the same frequency (for example: Think about a jet flying lowly over your head - Can you still hear what the person in front of you is saying?). So, getting rid of these tones that the human ear cannot hear anyways, is the compression method applied by converting audio files into MP3-format. In this sense, for our human hearing system, the MP3 format is lossless, however, if you see it from a technological point of view, it implies loss of certain tones of

your audio file. Consequently, MP3 format is referred to as a lossy compression method. MP3 usually is recorded at very low rates of around 256 kilobits per second, which is about 1/6 of the normal compact disc format using 1.4 megabits per second. This suggests, that MP3 audio files are not only saving a lot of storage space on your computer, iPod and so on, but they are consequently also faster to download, distribute etc.

In conclusion, I think that MP3 format made the life for music-lovers so convenient and comfortable that it is definitely one of the best inventions of the last decades.

Source: http://www.wisegeek.com/what-is-an-mp3.htm

http://www.wisegeek.com/what-is-mpeg.htm

Week 3 - Clear

This week the topic was "The Internet and World Wide Web". It is a very interesting and highly important topic to be informed about, I think. Especially for our generation of technology savvy individuals a world without the Internet is unimaginable. A concept that was especially interesting to me was about "Wi-Fi".

I use a Wi-Fi connection of my MacBook and Ipod touch everyday. As was stated in the book, it is widely known as being the "short version" of "wireless-fidelity", but as Dr. Means in the lecture already mentioned, this is not correct. I wanted to know where this name "Wi-Fi" really comes from and thus visited the homepage http://wi-fi.org in order to find that out. Unfortunately, on this website I was not able to find any information regarding the or

iginal of the Wi-Fi name. Thus, I searched Wikipedia, the to me best known wiki on the Internet, and found the reason why I could not find any explanation on the creation of this name:

This name was simply not intended to mean anything.

It was a plain "play on words" of "Hi-Fi", which later on got to be interpreted as being a short name for "wireless fidelity".

However, after clarifying the non-existent explanation of this brand name :), I would

like to dig a bit deeper in what this mysterious technology is all about that magically provides us with information regardless where in the world we are provided that we have a Wi-Fi compatible device available and we are somewhere where this sign appears:

Wi-Fi is actually a brand owned by the "Wi-Fi Alliance" that includes more than 300 companies, amongst which are Apple, IBM, Microsoft, and Nokia. It was founded in 1999 as a "global non-profit organization" with the aim to develop a "single global standard for high speed wireless local area networking (WLAN)". The devices, which are able to access this WLAN, are based on IEEE 802.11 standards. These standards express that these WLAN products use the 2.4, 3.6, and 5 GHz frequency bands (also known as radio waves) to communicate.

A device of any company can be "Wi-Fi certified", meaning that they can acquire a Wi-Fi logo to show customers that their products conform to the IEEE 802.11 standards. Hence, one can access the Internet with these devices, connect to other devices, or even to other networks which use Ethernet technology anywhere, where such a Wi-Fi Hotspot is. This presents a very important positive aspect of the Wi-Fi Technology, namely its interoperability. This means that you can use Wi-Fi with any device from any company and you do not get locked into one specific brand.

I hope, that you found this little excursion to what Wi-Fi actually is, was intended for and how it makes the connection of our phones, laptops, and so on possible, as interesting as I did.

Week 2 - Muddy

Appendix A explained "Coding Schemes and Number of Systems", which contained a very clear guideline to how computers code information. However, they also tried to explain the concept of a "Parity Bit", which I did not understand at all, even after reading it several times.

Thus I searched the Internet for a clearer explanation. I found many pages elaborating on this concept, but none of them contained such a good description as Wikipedia and wisegeek.com did. With the help of these two webpages and the book, let me explain what a "Parity Bit" is:

Every computer stores data in his memory. A computer does so either in even- or in odd-parity, meaning that for a computer with even-parity the total number of ones in bits in the byte must be an even number. (The same applies to odd-parity!)

So far this was, what I understood from the book. Now it comes to the muddy explanation of the book, which I ill explain by using the information gathered via Wikipedia and wisegeek.com (the following table from wikipedia.com helps in understanding the concept):

7 bits of data (number of 1s)	8 bits including parity
	even	odd
0000000 (0)	00000000	10000000
1010001 (3)	11010001	01010001
1101001 (4)	01101001	11101001
1111111 (7)	11111111	01111111

Any byte consists of 8 bits of data, 7 bits plus the parity bit. The 7 bits contain the data to be stored whereas bit number 8 exists to check for errors. Bits are binary, which means that they consist of only "1"s and "0"s. So whenever data is transmitted to a computer, this machine has to make sure that the data does not contain any error, in example that means in a computer with even-parity, the 7 bits have to include an even number of "1"s within every byte. If they do not, the parity bit is set to "1" in order to assure that the byte contains an even number of "1"s. Otherwise, if the byte has an even number of "1"s the parity bit is simply not "switched on" and shows a "0". This way the computer ensures that the data, which is being stored in its memory or even only received by it, is accurate and free of errors.

I hope this explanation makes the concept of "Parity Bit" clear to all readers as it is to me now!

Sources: http://www.wisegeek.com/what-is-a-parity-bit.htm

http://en.wikipedia.org/wiki/Parity_bit

Week 1 - Clear

The first week's readings were dealing with "Information Search, Netiquette, and Copyright". In my opinion it was a very interesting and furthermore important topic to be informed about, as we as students in today's business environment can almost not interact, work, communicate, or research without making use of the Internet. Especially the topic of "Copyright" caught my attention, as I have not been taught anything about this before.

Basically everything can be copyrighted: books, plays, music, movies, pictures and every form an idea takes. A Copyright is a law, which permits the owner of it to exclusively use his material/work. Any other person that wants to utilize this material either needs to request permission from the copyright owner to use it, or has to retrieve the material from a public domain, where everyone has access to it anyways.

If you are a student, scholar, or educator preparing a multimedia project or you use material for commentary, parody, news reporting, or research, you can use a legal defense called "Fair Use" whenever a copyright owner claims infringement. However, this is no exception from the legal obligation to respect copyrights, it only prevents you from being sued when you can proof that you used copyrighted material according to the following four rules:

1. "The purpose and character of the use, including whether such use is of a commercial nature or is for non-profit, educational purposes." (So when you profit from using this material, this may not be considered "fair use".)
2. "The nature of the copyrighted work"; namely if it is purely factual material, the usage of it may be more considered as "fair" than if you use someone's creative work.
3. "The amount and substantiality of the portion used in relation to the copyrighted protected work as a whole", which is judged individually and according to common-sense by the court.
4. "The effect of the use on the potential market for or value of the copyrighted work."

So, in the future I and now also all my blog readers know what to look for whenever using the work of anyone else.

Source: http://www.copyright.com/viewPage.do?pageCode=cr10-n