Web 2.0 products try to offer a new dimension of the Internet besides the glossy buttons and big, clean fonts : social network that connects relationships. David Sacks, the founder and CEO of new start up Geni says in his article from TechCrunch that sharing information with others is an evolution from basic search. He also mentions Facebook’s new developer platform that allows users to “effortlessly access information that is comprehensive and personal to them.” What he means is that since your friends is likely to have common interests with you, their suggestions or information they provide are more likely to be useful and less time-consuming to find.

This article attracted many users with interesting comments. The first that strike me was that depending too much on the information from networking sites can limit your scope of information and dull your views about the world. For example, getting movie recommendations from your close friends could hinder you from checking out professional movie reviews from others and missing out other great movies that you might like.

Also, the Facebook is criticized for not reflecting the complex and multi-layered social networks that people build in real life. One would ask different people for different things because they excel in that area. Relationships can also be deep or thin-surfaced, personal or professional, and long-term or short-termed. You might want to show your Facebook profile to your friends, but not to your professor or your employer. Facebook does not yet understand the richness of social networks.

Relating Web 2.0 to INFO 204 Networks class, relationships on the web can be referred to as a social-affiliation network, since social networking sites tend to build on affiliated activities. Edges can form when there are two people with a friend in common, two people with an activity in common, or a person joining an activity that a friend already participates in. On the web, this definition of activity could apply broadly to news, photos, events, music, political campaigns- and the lists are growing faster.

What is interesting is that from this kind of network, is one more likely to build social relationships that would help them find information they need and advance in life or rather spend more time and energy swimming in a big pond of information? What would happen to the quality of incoming information if we expand these kinds of social networks and how would we deal with it? We learned in class that we are more likely to hear about a promising job opportunity from a person we are not that close to. To what extent would weak ties be useful to us and how can networks be structured so that weak ties on the web such as small information about the news shared through digg can be helpful to us and not harmful? Incorporating multi-dimensional nature of human relationships into networks will be challenging but it would be exciting to watch online social networks evolve and fulfill our social needs.

          I was recently informed of several service companies which perform tasks that directly relate to several of our class discussions and topics.  There are numerous companies which make a profit by running switchboards between various wireless and land line phone companies.   Without getting technical (because it would not be that much fun to read and I wouldn’t be able to clearly explain the technicalities anyway) these companies serve to make sure that someone using a phone with Sprint service can reach their best friends who uses Verizon as their wireless carrier.  They quite literally create edges between networks, more specifically between specific nodes within a network.  However, the edges they create are more akin to the bridges we studied in class due to their nature, specifically their ability to link two large networks together.

            The link provided here http://www.verisign.com is a link to VeriSign’s website. Verisign is a telecommunications company which operates an array of network infrastructures.  In addition they also perform the service described above as well as number portability which I elaborate on in the following paragraph. 

            As stated earlier, Verisign and other similar companies offer a service known as Local Number Portability.  This “portability” refers to the ability to retain ones telephone number, wireless or otherwise, when a customer decides to either move (physically geographic location) or switch phone companies.  This service prevented the changing of operators with a person moving from on geographic location to another.   This topic relates to what we have been discussing in class because number portability, is in actuality the moving of a node (a person) from one network (say Sprint) to another (say Verizon). 

Try playing this game: http://www.predictablyirrational.com/?page_id=117

In this door game, you are given the choice to click on one of three doors. You only have 50 clicks to use, so you must use your clicks wisely. All the doors start out closed, and you must click on a door to open it. Opening one door closes the others. By clicking on the open door, you will earn some number of points. Each click on an open door can give you a different number of points.

 In one round of this game, the doors remained a fixed size. In other rounds, doors will shring each time they are not clicked on, until eventually the doors disappear. This feature of the game proved to affect some of the players’ strategies, causing them to go back and forth between doors so that the doors would not disappear.

In this article http://www.nytimes.com/2008/02/26/science/26tier.html?pagewanted=1&_r=1&ref=science, Tierney discusses the disadvantages of keeping options open. In the door game, it is evident that keeping doors from disappearing had costs: it cost a click to open a new door and there was an opportunity cost from not clicking on the door that was already open. The article suggests that when options are threatened to disappear, decision makers try harder to keep these options available, even if the options seem to be of little benefit.

 Dr. Ariely, a professor at MIT in behavioral economics, has performed experiments, like the door game, that explore the incentives of keeping options open. His research has shown that people keep options open because of their aversion to loss and their overvaluation of these options. This article relates to the game theory that we have discussed in class. Though the best strategy is to stick to one door in this particular door game, other factors cause us to act irrationally. It is interesting to see how simiple notions such as disappearing option can distract a player from choosing the best response.

eBay has been in the news lately for a recent revision to its fee structure for sellers. Being one of the largest established trading networks, eBay has a lot of long-time users, some of who did not take kindly to the fairly radical changes in its auction rules. In fact, some sellers even went so far as to organize a boycott of eBay in response to the new rules.

Ultimately, however, efforts like the boycott had little effect on the overall sales on eBay. What could matter more in the long run – and what makes this whole fiasco relevant to the class – are the changes that were made at the same time to eBay’s feedback system. For those who have never used eBay, buyers and sellers were allowed to rate their trading partner on their conduct during the transaction. There were three choices: positive (+1), negative (-1), or neutral (0). All of a user’s feedback ratings were tallied to compute a collective feedback score, which acted as a metric of how well the user could be trusted. Under the new changes to the feedback system, however, buyers can only receive positive feedback, and older feedback doesn’t count towards your score.

We can look at the network of eBay users as a graph with two types of nodes – buyers and sellers – feedback scores serving as the weight on each node. To determine whether or not a buyer and a seller will trade, we can consider the sum of the weights of both buyer and seller: a higher sum means a higher likelihood that the transaction will place (i.e. that the bidder will place a bid and that the seller will accept that bid).

The real question underlying the changes is how accurately feedback scores represent a user’s reliability. If we believe eBay’s take on the situation – that the changes “increase buyer confidence and showcase good sellers” – then we would expect to see more connections being made under the new system (i.e. increased trading volume) as a consequence of that increased buyer confidence in the reputation of their sellers. If, however, we instead believe the protesters, then we’d expect fewer trades and a higher level of distrust amongst buyers and sellers. At this point, there is not enough perspective to make a determination either way; as TheStreet.com pointed out, recent fluctuations in trading volume on eBay were most likely the result of the beginning and end of a promotional period and had nothing to do with the announced changes. It will be interesting to watch and see what the ultimate effect of these changes will be on the Internet’s largest marketplace.

http://www.users.globalnet.co.uk/~ebdstudy/strategy/ecosys.htm

Ecosystem Systems Theory analyzes the interactions of people in networks encompassed in an ecosystem or certain environment. Schools serve as interesting domains for such studies because children undergo many changes in their relationships during periods in their lives, such as during elementary school. The attached article discusses the ways in which a teacher can deal with a disruptive student. It states that such students are children who seek to maintain balance in their lives.

From a networks perspective, this scenario becomes more comprehensible. For our purposes, let us denote three triads: A being between the child, mother, and father, B being between the child, teacher and mother, and C being between the child, teacher and father. Let us assume that the child’s relationship with his parents is antagonistic. The child thinks that he is misunderstood, and his parents, with a positive edge between them, are trying to help him. (For triad A to be structurally balanced, the parents must have a good relationship with one another). Now as a result of the child’s negative tensions with his parents, he releases these tensions in class on his teacher. The concept of structural balance can explain this phenomenon. From our assumption, we know that triad A is structurally balanced. In triad B, we can assume that the mother and the teacher share a positive edge, perhaps because the mother and teacher are working in conjunction to help the child to be less disruptive and disobedient. Thus, triad B has a positive edge between the mother and teacher and negative edges between student, teacher and student, mother. Since triad C is identical to triad B (dealing with the father instead of the mother), the entire network is balanced.

Now what does this indicate to an outside observer? One can assume the parents and the teacher would want to flip the negative edges in the networks to positive ones. In this case, all negative edges branch from the child. In theory, if any of the edges become positive, that is if the child makes a positive connection with at least one of the other nodes, then the problem could be remedied. If one node is changed in any triad of the network, the network becomes structurally unbalanced. This fact opens up the possibility for the network to become structurally stable with all positive edges. For instance, if the teacher can reach through to the student and solve his problem, the edge between the child and the teacher will become positive, and triad’s B and C will thus become unstable due to the presence of two positive edges and one negative edge. If efforts to help the child are effective and the parents are lucky, the network will stabilize as a result of the child accepting his parents and with all edges being positive, everyone will be happy.

http://www.users.globalnet.co.uk/~ebdstudy/strategy/ecosys.htm

Ecosystem Systems Theory analyzes the interactions of people in networks encompassed in an ecosystem or certain environment. Schools serve as interesting domains for such studies because children undergo many changes in their relationships during periods in their lives, such as during elementary school. The attached article discusses the ways in which a teacher can deal with a disruptive student. It states that such students are children who seek to maintain balance in their lives.

From a networks perspective, this scenario becomes more comprehensible. For our purposes, let us denote three triads: A being between the child, mother, and father, B being between the child, teacher and mother, and C being between the child, teacher and father. Let us assume that the child’s relationship with his parents is antagonistic. The child thinks that he is misunderstood, and his parents, with a positive edge between them, are trying to help him. (For triad A to be structurally balanced, the parents must have a good relationship with one another). Now as a result of the child’s negative tensions with his parents, he releases these tensions in class on his teacher. The concept of structural balance can explain this phenomenon. From our assumption, we know that triad A is structurally balanced. In triad B, we can assume that the mother and the teacher share a positive edge, perhaps because the mother and teacher are working in conjunction to help the child to be less disruptive and disobedient. Thus, triad B has a positive edge between the mother and teacher and negative edges between student, teacher and student, mother. Since triad C is identical to triad B (dealing with the father instead of the mother), the entire network is balanced.

Now what does this indicate to an outside observer? One can assume the parents and the teacher would want to flip the negative edges in the networks to positive ones. In this case, all negative edges branch from the child. In theory, if any of the edges become positive, that is if the child makes a positive connection with at least one of the other nodes, then the problem could be remedied. If one node is changed in any triad of the network, the network becomes structurally unbalanced. This fact opens up the possibility for the network to become structurally stable with all positive edges. For instance, if the teacher can reach through to the student and solve his problem, the edge between the child and the teacher will become positive, and triad’s B and C will thus become unstable due to the presence of two positive edges and one negative edge. If efforts to help the child are effective and the parents are lucky, the network will stabilize as a result of the child accepting his parents and with all edges being positive, everyone will be happy.

http://www.users.globalnet.co.uk/~ebdstudy/strategy/ecosys.htm

Ecosystem Systems Theory analyzes the interactions of people in networks encompassed in an ecosystem or certain environment. Schools serve as interesting domains for such studies because children undergo many changes in their relationships during periods in their lives, such as during elementary school. The attached article discusses the ways in which a teacher can deal with a disruptive student. It states that such students are children who seek to maintain balance in their lives.

From a networks perspective, this scenario becomes more comprehensible. For our purposes, let us denote three triads: A being between the child, mother, and father, B being between the child, teacher and mother, and C being between the child, teacher and father. Let us assume that the child’s relationship with his parents is antagonistic. The child thinks that he is misunderstood, and his parents, with a positive edge between them, are trying to help him. (For triad A to be structurally balanced, the parents must have a good relationship with one another). Now as a result of the child’s negative tensions with his parents, he releases these tensions in class on his teacher. The concept of structural balance can explain this phenomenon. From our assumption, we know that triad A is structurally balanced. In triad B, we can assume that the mother and the teacher share a positive edge, perhaps because the mother and teacher are working in conjunction to help the child to be less disruptive and disobedient. Thus, triad B has a positive edge between the mother and teacher and negative edges between student, teacher and student, mother. Since triad C is identical to triad B (dealing with the father instead of the mother), the entire network is balanced.

Now what does this indicate to an outside observer? One can assume the parents and the teacher would want to flip the negative edges in the networks to positive ones. In this case, all negative edges branch from the child. In theory, if any of the edges become positive, that is if the child makes a positive connection with at least one of the other nodes, then the problem could be remedied. If one node is changed in any triad of the network, the network becomes structurally unbalanced. This fact opens up the possibility for the network to become structurally stable with all positive edges. For instance, if the teacher can reach through to the student and solve his problem, the edge between the child and the teacher will become positive, and triad’s B and C will thus become unstable due to the presence of two positive edges and one negative edge. If efforts to help the child are effective and the parents are lucky, the network will stabilize as a result of the child accepting his parents and with all edges being positive, everyone will be happy.

http://www.users.globalnet.co.uk/~ebdstudy/strategy/ecosys.htm

Ecosystem Systems Theory analyzes the interactions of people in networks encompassed in an ecosystem or certain environment. Schools serve as interesting domains for such studies because children undergo many changes in their relationships during periods in their lives, such as during elementary school. The attached article discusses the ways in which a teacher can deal with a disruptive student. It states that such students are children who seek to maintain balance in their lives.

From a networks perspective, this scenario becomes more comprehensible. For our purposes, let us denote three triads: A being between the child, mother, and father, B being between the child, teacher and mother, and C being between the child, teacher and father. Let us assume that the child’s relationship with his parents is antagonistic. The child thinks that he is misunderstood, and his parents, with a positive edge between them, are trying to help him. (For triad A to be structurally balanced, the parents must have a good relationship with one another). Now as a result of the child’s negative tensions with his parents, he releases these tensions in class on his teacher. The concept of structural balance can explain this phenomenon. From our assumption, we know that triad A is structurally balanced. In triad B, we can assume that the mother and the teacher share a positive edge, perhaps because the mother and teacher are working in conjunction to help the child to be less disruptive and disobedient. Thus, triad B has a positive edge between the mother and teacher and negative edges between student, teacher and student, mother. Since triad C is identical to triad B (dealing with the father instead of the mother), the entire network is balanced.

Now what does this indicate to an outside observer? One can assume the parents and the teacher would want to flip the negative edges in the networks to positive ones. In this case, all negative edges branch from the child. In theory, if any of the edges become positive, that is if the child makes a positive connection with at least one of the other nodes, then the problem could be remedied. If one node is changed in any triad of the network, the network becomes structurally unbalanced. This fact opens up the possibility for the network to become structurally stable with all positive edges. For instance, if the teacher can reach through to the student and solve his problem, the edge between the child and the teacher will become positive, and triad’s B and C will thus become unstable due to the presence of two positive edges and one negative edge. If efforts to help the child are effective and the parents are lucky, the network will stabilize as a result of the child accepting his parents and with all edges being positive, everyone will be happy.

http://www.youtube.com/v/3xKZ4KGkQY8

Many computer science industry experts believe that  in the future a personal computer will consist of just an internet connection, mouse, keyboard and screen. All of your files, programs and even your operating system will live on some remote server, which means you will be able to access the exact same information regardless of where you are or who’s computer you are using. A first step in this direction is storing your files on the internet, rather than on your local hard drive. A startup company called Caleido AG, which is based out of Switzerland, has created a program called Wuala that attempts to move in this direction.

Wuala is a distributed file system that essentially stores your files dispersed on a network of all the other Wuala users’ hard drives.  From the user’s perspective Wuala is simply a program that takes over a certain amount of your hard drive and, in return, stores your files online (on the space that other Wuala users have allocated on their computers) so that you can access them from anywhere you have an internet connection. Obviously there is the problem that if you only store your data on Wuala, you can’t access it when you aren’t online, but in today’s world this problem is rapidly disappearing.

What becomes interesting from the point of view of a networks class is how the Wuala network actually works behind the scenes. It’s major challenge is how to guarantee you a path to your data and figure out what that path is on an enormous and dynamic network. When you store your files on a network of random computers where any node of the network can disappear at any time is what happens if the computer storing your data disappears from the network when you need access to your data, or worse yet, disappears for good? The way Wuala solves this is by dividing your data into many chunks, using a complicated algorithm (called erasure codes) that allows the file to be recreated without actually having all the chunks, just most of them.  It then sends out a few copies of each of these chunks to be stored on other computers.  Occasionally Wuala will check that enough of these chunks still exist and will send out more if there aren’t enough. Wuala estimates that using this method your data will be available 99.99% of the time. In a sense this is like a social network, in that there are many nodes (the ones holding your data) that are your friends and many other nodes that you can see but you only have a weak connection to them (since they don’t hold any of your data).  Occasionally one of your friends gets out of touch or becomes your enemy, in which case you’ll need to go out and create some new edges or strengthen some weak ties.

Another network related issue that Wuala has to deal with is how to get all of the file fragments from the nodes where they are housed to your computer when you want to open the file. This is similar to the traffic problems that we did in class, but also involves the concept of powerful nodes. Here the problem is that your computer’s node does not know where the data you want to access is being kept, so it doesn’t know which node to request it from or how to get to that node. To solve this, Wuala created a large network of what it calls Super Nodes (read powerful nodes). Every Super Node is connected to about 1/100,000 of the other Super Nodes in addition to its local client nodes, and these edges are strategically placed so that it is connected to all the nearby Super Nodes and a few dispersed far away Super Nodes. This creates Small World Effects (a concept that I believe Prof. Klienberg worked on) whereby every Super Node is connected to every other Super Node by relatively few edges, so as long as you send your request in the right general direction it will arrive at its destination. Wuala claims that on average it only takes their network three hops between Super Nodes to reach the destination. In the image above, the outside ring are all the clients who are not connected to the client in question; the middle ring are the clients who store this client’s data and the inner ring are the Super Nodes. The green lines that do some bouncing around are the requests and the blue lines are the data being sent directly from storage clients to the requester client.

There are many more interesting network related problems that a program like Wuala comes up with creative solutions for, but these, I think, are the most interesting.  Wuala still has a way to go before being really useful as a replacement for local storage (for example, right now you can only edit a file by downloading it, editing it and reuploading it) but it is certainly a first step on the path to eliminating the need for a personal computer and utilizing the internet to its fullest potential.

http://news.yahoo.com/s/ap/20080226/ap_on_bi_ge/home_prices;_ylt=AuboER25i9_MynoqFqv_R3ys0NUE 

In this recent article, the value of houses across the nation has dropped significantly, especially in the last quarter of 2007 when compared to previous years. Banks are repossessing the homes at an alarming rate, and pretty soon there may be a need for increased helped from the government. The reality is that unlike previous years, if you are currently looking to sell your home, there is a chance that you will not make a desired payoff.

This report can be tied with some of the material studied in class, such as the chapter on matching markets. Last year, for example, a majority of the transactions of houses involved an ascending (English) auction, where buyers would be competing for a house by increasing their bid. Unfortunately for some current homeowners, selling their house has become quite the opposite from the past. The situation can be represented with a bipartite graph. After organizing the information, we see that there are constricted sets and thus no perfect matching. In order for market clearing prices, a house must be priced at a lower cost, rather than higher that what the owner originally bought it for. This example of a descending (Dutch) auction may force sellers to have a negative payoff, depending how desperate they are to sell. A second possibility is that a seller, given his or her reservation price, may choose to wait for the housing market to get better before selling.

Mortgages are now only available for those with qualified credit, after more and more foreclosures occurred nationwide. This decline in the housing market has economists worried of an economic recession, even though the government has already passed an important bill of over 160 billion to help homeowners and their loans.