Week 6: Muddy

            The concept that was most difficult to understand this week was the differences between the various audio file formats. I learned which ones are popular and which ones are compressed, as well as some attributes about them. However, it is not clear to me which audio file format is used in a specific scenario. Mr. Olsen always talks about the importance of usage in choosing amongst different technology, and I don't know how to analyze which audio file format is best in a specific circumstance.
          This website provides a clear explanation of the different audio file formats. It explains that Wave files (wav) and MPEG Layer-3 files (mp3) are the most common types of audio files. This site divides the different file formats into open file formats and proprietary formats. WAV, AIFF, and MP3 are open file formats while WMA and AAC are proprietary formats. This is another website that clearly explains the topic of audio file formats. It breaks down technical jargon into simpler terms, explaining that a file format is simply a a specific way that codecs encode data in order for it to be saved as a file. It explains what the codec does and also how a lossy codec differs from a lossless codec. At the bottom of the website, it talks about the same audio file formats explained in the previous site and in class yet made them much easier to comprehend.
            WAV and AIFF are both uncompressed, lossless formats, and WAV is preferred by PC users while mac users rip CDs into AIFF. AAC is the lossy default audio format for Apple that was created to replace MP3. Though it never reached the same level of prominence as MP3, AAC wins in terms of sound quality to file size ratio. WMA is a compressed format owned by Microsoft that has Digital Rights Management (DRM) to control how a file is used or shared. Finally, MP3 is lossy with a high level of compression and is the most popular format for downlading and storing music. MP3 eliminates parts of the file that is basically inaudible and compresses the file to a small fraction of its original size. MP3 is ideal for music storage. Ultimately, these websites helped explain the topics further, and now I understand why any of these audio file formats would be chosen over any other one, depending on the situation. Here is a picture displaying the different audio file formats:

Works Cited:

http://www.nch.com.au/acm/formats.html

http://www.makeuseof.com/tag/a-look-at-the-different-file-formats-available-part-1-audio/

http://dvd-video-tools.com/images/ss/switch-b.gif

Week 5: Clear

             The concept that was most clear to me this week was creating formulas in Excel. The key to putting in formulas is they must begin with an equal sign. PEMDAS is important for formulas because it is the order of operations. It stands for Parenthesis, Exponentiation, Multiplication, Division, Addition, and Subtraction. A good way to remember this acronym is Please Excuse My Dear Aunt Sally. Multiplication and division are done from left to right, whichever comes first, and addition and subtraction are done together in this same manner. Excel uses + for addition, - for subtraction, * for multiplication, and / for division.
          Excel is very important in the business environment because it makes the process of performing math problems very easy. You can type in a formula that you need for an entire column based off of other columns and simply drag the bottom right corner down and the relative relationship remains the same. This saves alot of time, making Excel a helpful tool in any line of business that requires many computations.
         This website relates to the concept of creating formulas in Excel and even has a table showing the different formulas that can be entered using some sample data. This website goes a step further and shows formulas for exponentiation, square roots, cube roots, increasing/decreasing by a percentage, calculating percentages, and averages. It shows the exact formula that would be typed into Excel, beginning with an equal sign. This is an additional website that is basically a "how to" for creating Excel formulas and uses a basic addition and subtraction equation as an example. Here is an an example of how a formula is created and used in Excel:

Works Cited

http://www.cob.sjsu.edu/splane_m/excelformulas.htm

http://www.ehow.com/how_9699_create-excel-formula.html

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZa5oHig35Ol_MosDScXI2B4awz6NSKaM2fPZCn4tfhWZapCWjYkPPQ5j0OO4Aqz6qW9lFj6YvbLWMXYuuGkbHs203I3XRdnOkhSmBjFkNXQMzqEu5vsxd9t4ODTLw36tAFB8MW0cSay8o/s400/WMA+Weights+Excel+Formula.jpg

Week 4: Clear

           The concept that was most clear to me this week was the part of the software life cycle concerning software version numbers and upgrading the software. Software version numbers have four numbers. The first is the major version, the second is the minor version, the third is the revision number, and the fourth (which is optional and often dropped) is the build number. These numbers are very specific and important to the software. A patch is designated to provide minor updates like a new revision numbers or bug fixes. An update is a revision to a minor version, a new minor version, enhanced features, bug fixes, or other new features. An upgrade is a new major version or a major update to a minor version. An example of an upgrade is Microsoft Office had its 14th major version, so the major version number is now 14.
            Upgrading software is very important in the business environment because it can provide productive new tools. Upgrades can make the software more stable and reliable and might includes features that make work more efficient. Good software is never static but is rather constantly updating and evolving.
           This website explains the difference between a software upgrade and a software update. It adds to the above explanation that updates are often bug fixes or minor software enhancements and are often free to download. On the other hand, upgrades are often the purchase of a newer software version or your current software with more features.

Week 3: Clear

         The concept that was most clear to me this week was virtual memory. Virtual memory is a form of memory management to optimize the use of RAM. Multitasking can result in running out of physical memory, so the computer takes part of the hard drive and allocates it as a swap file, pretending it is an extension of the physical memory. The virtual memory is divided into fixed-size units called PAGES, some of which are on the disk and some of which are in the memory. The process of transferring a page between memory and storage is called swapping. Copying from virtual memory into physical memory chips is called SWAP IN, while the opposite process (from memory to storage) is called SWAP OUT. Virtual memory makes the computer's memory seem larger than it actually is by utlizing storage as additional memory. There is a tradeoff with virtual memory: although it enables oversized applications, it works slower than physical RAM.
        Virtual memory is important in the business environment because computers with this operating system use hardware memory more efficiently than computers without virtual memory and also make application programming easier. This integral part of the computer is important for optimizing memory allocation. Without the virtual memory, computers would easily run out of memory because they would not have enough physical RAM.
           This website clearly explains the concept of virtual memory.  It discusses how the virtual memory works and talks about configuring the virtual memory. I like the picture on this website that shows memory management between the CPU, cache, RAM, and virtual memory as part of disk storage. I also found this video interesting since it explains how to increase performance with the virtual memory.  Here is a pyramid visualization of the memory hierarchy:

Works Cited:

http://computer.howstuffworks.com/virtual-memory.htm

http://www.youtube.com/watch?v=L2igH6O0ARM

http://static.howstuffworks.com/gif/computer-memory-pyramid.gif

Week 2: Muddy

           This week I found the concept of RAID the most difficult to understand. In the lesson on storage with computer systems, I learned about RAID0 and RAID1. RAID0 excels with speed and capacty and allows two or more disks to apear like a single disk. This allows for either increased capacity and speed or more reliability. RAID0 allows for double the capacity because it uses more than one hard drive. The danger with RAID0 is that single disk failure causes the loss of all data since it is evenly distributed aross the disk drives. On the other hand, RAID1 is always done with two disk drives, and everything written on one disk drive is written on the other disk drive to create "mirror images." This can be expensive, but it produces higher reliability. Overall, if you want a system that is always available and uptime is also a concern, then RAID1 is ideal because it protects against single drive failure.
          This concept doesn't make sense to me because I don't see a clear distinction between RAID0 and RAID1. I don't understand how RAID0 appears like a single disk and can allow either increased speed and capacity or increase reliability. How can these be separate concepts?

                 I had difficulty understanding this concept primarily because I could not visualize the difference between RAID0 and RAID1. At this website I was able to fnd a better explanation of the differences between RAID0 and RAID1. It broke down the advantages and disadvantages, making the concept easier to understand. I think what helped me the most was the picture on this website which showed me what was meant by striping and mirroring. At the bottom of this post is a separate picture that also helped me visualize RAID0 and RAID1.