Week 2 workshop Assignment Example | Topics and Well Written Essays - 500 words

Week 2 workshop - Assignment Example The graph is now positively skewed from mean as shown in the diagram below: The appropriate measures of central tendency for skewed distribution are either mean or median. Median is a more appropriate measure for highly skewed distributions. The skewness of the graph that we have plotted is not very high. Hence the best measure of central tendency is the mean. The average salary of the corporate customers is now $345,455. Gender is an example of nominal data. It can take either of the two values: Male or Female. Mode which is the value which has the highest frequency in the given data set is the best measure of central tendency in this case (QuickMBA, 2010). The mode of the distribution will tell us whether the data has more males or more females which is an appropriate measure for central tendency. The three key different measures of central tendency are Mean, Median and Mode. All the three are not the best measures for all types of distribution. They have different values for differently skewed distributions. For a symmetrical distribution, all the three measures converge on the same value. Mean is the most sensitive measure to skewness (Levin and Rubin, 2009). In case the distribution contains outlier values which impact the skewness of the distribution positively or negatively, the mean moves from being the highest (positively skewed distribution) to being the lowest (negatively skewed distribution). In any distribution, median is always in the middle of mean and mode. Median is the least sensitive measure for skewed distributions. Standard deviation and variance are both the measures of dispersion. Standard deviation is the square root of variance. Variance is the average value of the squared difference of the each value and the mean. Since variance is calculated after squaring, all the differences take positive value. Moreover, larger differences get more weight and are more suitable in cases where there are more outliers. Standard

An analyzed look into current botnet controls Thesis Proposal

An analyzed look into current botnet controls - Thesis Proposal Example Practically speaking one botnet could be made up of ten thousand machines.It is quite difficult to identify since they are vigorous in nature. This is in order to escape the security measures put in place. This is done through the download ofsoftware called a â€Å"bot† for example AgoBot. The download comes along with afixed payload incurred by an un-suspecting user. This download is executed through the clicking of email attachments that have been infected ordownloading infected files from malicious websites. The bot software can also be transmitted as freeway in peer to peer networks. After the installation of the bot with the fixed payload in the computer, the machine makes contact with a public server set up by the botmaster. This server is the control panel that is used to give commands to the botnet. A popular procedure involves using public (IRC) Internet Relay Chat servers. The control panels are frequently changed to avoid being detected. They are managed by machines and proxies that are not owned by the botmaster. The botmaster uses the control panel to send new exploit-code to the bots or to modify the bot-code so as to avoid detection through signature methods. This code is also used to insert new commands and attack victims (Patrick Lee, 2009). The botmaster’s main objective is to enlist new nodes into the botnet. A node is any computer that is connected to the internet hence making it a target for attack. Each node is commanded to search for other potential hosts. This pattern follows for every other machine that is recruited into the botnet. Therefore the machines that were in the botnet before and the new continuously carry out the search. Within a few hours, a botnet can become very large with a composition of millions of PCs on different network throughout the world. Given the large number of zombies distributed