Since its creation, the Internet has been a fast and easy way for people to communicate and share information.  Starting with basic networks whose nodes could be counted with your hands, the Internet has evolved into a gigantic web spaning the entire globe and linking billions of its inhabitants.  Similar to the Pony Express and telegram of the past, the Internet has become one of the primary ways people send and receive information, not to mention learn about other people, places and things that they may never actually see in person.

     Initially, finding the person you wanted to communicate with or the file you wanted was simple; there were only a limited number of users.  As the net expanded, search engines alleviated the process of finding who or what you wanted in a timely fashion with relative ease.  Today, however, the Internet is so busy and full of people, applications, and information that it is often difficult, if not impossible, to find exactly who you want to talk to or what you want to look at if you do not already know where to look.

   An interesting project I found in doing research for this blog post was FOAF.  FOAF, which stands for Friend-Of-A-Friend, was started by Dan Brickley and Libby Miller in 2000 in order to find out who is on the Internet, what role or space they occupy, how different users and programs interact and connect, and how their information could be shared more simply and quickly.  FOAF allows users to create profiles saying who they are, what they do, and who they interact with, creating a web of connections that can be viewed and studied, similar to the networks we have looked at in class.  It also allows people to post their files and web-pages for sharing and, by directing them to use simple code and terminology when adding their resources, creates a series of machine-readable pages that can be sequenced and categorized, allowing for quick and easy searching of information and programs.  Instead of having to wade through the endless pages of useless sites on search engines, users can quickly and easily find who and what they are looking for thanks to computer processing and scanning of information.  They can also find people who have interests similar to theirs and who may be friends of their friends or acquaintances, thereby bridging gaps and connecting individuals and groups in various social and net networks.

    I thought this project was a particularly interesting study of the social and computer networks we looked at and neat way of using existing connections between people and machines to make information on the Internet easier to find and therefore more accessible.  Often times on the net I feel a little lost and get frustrated that I am not finding what I am looking for, and so I think FOAF is a step in the right direction in making the Internet more friendly and making time spent on it more worth-while.  You can find FOAF’s homepage and information about getting started at http://www.cs.vu.nl/~pmika/social.html .

http://www.usatoday.com/tech/science/columnist/2006-06-25-physics-of-ebay_x.htm

http://www.newscientist.com/article.ns?id=dn9398

In class, we discussed how auctions on eBay are essentially second price sealed bid auctions. We also noted that in these types of auctions, bidding one’s true value is a dominant strategy. But some of the unique properties of eBay auctions - their fixed time limit and the fact that people can bid as many times as they like - open up new dimensions of bidding strategy. For example, many bidders employ the tactic of sniping: placing a bid very close to the end of the auction so that no one has a chance to outbid you.

Recently, researchers created a mathematical model that analyzed a large number of eBay auctions. They determined that the strategy that gives the highest probability of winning is to place a single bid near the end of the auction, rather than placing incremental bids throughout its duration. One of the reasons that this works is because it causes early bidders to believe that there is a lack of competition. Thus, they may feel that it is unnecessary to bid their true value. In this sense, the research reinforces the notion that bidding your true value, especially if you are a casual eBay-er who does not have the time or resources to snipe, is a dominant strategy, just as in a typical second price sealed bid auction.  In fact, this is the strategy that eBay recommends, because they will submit proxy bids for you until your maximum is reached.  Essentially, if you assume that people will try to snipe at the end of the auction, then bidding your true value increases your chances of receiving a non-zero payoff.

In class, we explored the advantages of being embedded in a network. As opposed to a node that lies on the fringes of a network, a node in the center of a network has edges with every node in the network, which allows it to interact with these other nodes directly. The influence of this position was explored in a study of social networks conducted in the UK.

This study can be found here:

Health intervention in social context: Understanding social networks and neighbourhood

An organization called Community Health Educators (CHE’s for short) was studied, because they recruited individuals from the neighborhoods of target communities for health interventions because these individuals were assumed to be well embedded in those networks. There were 53 CHEs, half of whom were white (the white CHE’s) and the half whom were from minority ethnic groups (the BME CHE’s). Quantitative data, such as the number of clients that had that were either family, friends, or acquaintances, was collected to establish a ratio of embeddedness.

The basis of these scores can be seen in this diagram:

Qualitative data, such as interviews with the CHE’s, were also collected. These interviews also helped to explain some of the quantitative data.

Despite the fact that this study was rather crude in its attempt to measure embeddness, it still offered new insight into the pathways of social networks. The results from this study show that even though a well embedded node might have many connections within its network, it still might not be as effective as less embedded node in spreading and gathering information. This all relates back to the concept of strong and weak ties, and structural holes. In this study, a majority of the embeddedness resulted from the presence of strong ties between the CHE’s and their communities. This meant that these CHE’s use their families and friends as clients or as a source for finding clients. But since strong ties exist between these CHE’s and their networks, this means that homophily is present as well. Since there are most likely edges between all these nodes in these networks, the influence that a CHE can have is, in a way trapped within these edges.

The consequences of these strong ties can be seen here:

On the other hand, this study shows that structural holes are a better determinant of structural ties. This can be seen in the data collected from one of the CHE’s, who was referred by friends of clients.

Her network can be seen here:

From this graph, we can see that the non-redundant relationship that results from structural holes is more effective in health promotion.

Last Call: Analog Cell Phone Service Disappearing:

http://www.pcworld.com/article/id,142119-c,cellphones/article.html

When one thinks of networks one usually thinks of a large cellular network. On February 18 analog cell phone service will be shut down permanently. AT&T and Verizon, the “biggest U.S. mobile operators” decided that there will be no more analog service offered on their network. Whether it be for financial, maintenance or other reasons, these companies decided it is not worth their power to have analog service. What does this mean for consumers using analog cell phones? It means that this group will have to find another way to receive cell phone service. Referring to the diagram, the analog cell phone node was a gatekeeper for some consumers to receive cell phone, home security and OnStar services. Customers will have to form a new bridge with the digital node in order to reach the phone companies.

However, some consumers don’t have this luxury. The lucky members of cell phone group C, in the diagram, will not be able to have cell phones at all. This is due to the fact that in some remote areas only analog signal can be used. Analog signal has a much longer range than the new digital towers and therefore is needed in some areas. All early vehicles with OnStar must now be serviced for an updated digital system. Also, house owners with security systems will not be able to use analog service. This means if a burglar cuts a home’s phone line, there will not be an analog cell phone call made to the police. You may think these analog groups are only a few people and only constitute a small percentage of these companies’ consumers, but this group consists of people numbering in the hundreds of thousands.

Cellular Network Graph

Recently, a New York Times article announced the thought of a merger between the social network powerhouse, MySpace, run by Rupert Murdoch, and the BBC. This expansion of internet broadcasting will further increase the already large networks that the BBC and MySpace have already built. As most of us know, MySpace is an immensely popular social network, in which people can ‘friend’ one another, and communicate about various interests. It has also become a way for up and coming musicians to gain a larger audience, by promoting their music on their sites with free downloads and music videos.

BBC and MySpace can be viewed as two large global networks, similar to what was discussed in class regarding the possibility of more than one large network of friends across the globe. The presence of BBC poses as a new group for individuals to join. This process of bringing a multitude of younger internet users together can potentially form new links between users. These links are considered weak links, but large amounts of these new connections lead to new communications, friendships and the sharing of new or similar ideas.

Since MySpace is constantly expanding, and continues to thrive because of its popularity, the influx of members that would result from this partnership could be viewed very positively. The BBC’s goal is to generate conversation and commentary on their own blogs between MySpace users. Provided that this gains popularity among the community, it will create links to each MySpace user that decides to utilize the BBC blog.

Link: http://www.nytimes.com/2008/01/24/business/media/24myspace.html?_r=1&scp=1&sq=BBC+and+MySpace&st=nyt&oref=slogin

Growing up in Rwanda, I didn’t know I was going to meet most of the friends I have now in the United States. I was not thinking that at one point  in my life I will be having many friends from different parts of the world especially China, Indonesia and the United States itself were Cornell University is located, but since I had a strong attachment to school (Cornell University). I got to meet a lot of other friends who had also strong attachment to school. Some of my friends we got to develop a strong relationship, while others we have a weak relationship. Whatever the case the school brought us together. If it wasn’t for the school I would have not had a chance to meet them or they would have not had a chance to meet me. So school fulfills a triadic closure. School is a gate I went through to meet my new friends, and is a gate I am going through to get my bachelors degree.

Rwanda is a social network on its own, and the United States is another social network on its own. Both of these countries have different cultures and different ideas. If there was not movement cross these two countries, idea and cultures would remain in their native countries. That is, People in Rwanda would know nothing, but their culture and same would apply to the people in United States. I consider myself a bridge that is connecting Rwanda to the United States, the ideas that I will acquire from Cornell University, I will take them to Rwanda, where I will be sharing them with my fellow Rwandese, and this will make Rwanda better off because I will have introduced new ideas which they would have not otherwise received, if I had not bridged the gap between the United States and Rwanda.

Silicon Valley is known for the destination of the many big tech companies such as Cisco, Yahoo!, Google, Facebook, etc. One might wonder why these great technology companies of today are centrally, if not started, in the Silicon Valley. Silicon Valley, “has long been the model of success for a modern regional economy”(NYT), and other states and even the world try to duplicate the network of Silicon Valley, hoping to achieve the same growth and success as many companies sprouted from Silicon Valley did.

 To further stress the importance of Silicon Valley network and why it’s important to study the network, there was a recent study of Cleveland economy and Silicon Valley economy. “The Study is summarized nicely:

“Cleveland is a perplexing economy,” according to Dr. Christine Chmura, President and Chief Economist of Richmond-based Chmura Economics & Analytics, “It should be growing faster than it is because the industry mix is more favorable than the state and the region has so many attractive qualities such as the arts, cultural attractions, recreational opportunities, and professional sports teams.”” (A Perplexing Economy).

 Cleveland economy network:

Silicon Valley economy network:

The nodes in the network represent industry mix, cultural attractions, etc. The Cleveland network shows that it’s not the lack of nodes that the economy might not be doing as well as the Silicon Valley network. The Silicon Valley network demonstrates that the economy require intersection and the interconnection of knowledge. Therefore, this is one of the reasons why studies of the network of Silicon Valley are necessary to understand or duplicate the economic growth.

 The article done by a group in Silicon Valley Network Analysis Project (SiVNAP) describe that there are two major elements besides others that describe the nature of Silicon Valley Network. One of the major elements is the role of Stanford. “In the 1950s, two institutional innovations—the University Honors Cooperative Program and the Stanford Industrial Park—brought together university researchers and nascent industry interests. Stanford Industrial Park (now called Stanford Research Park), conceived by Stanford provost Frederick Terman and officially founded in 1951, was the first of its kind.” (Social Networks in Silicon Valley). There were many companies including many Stanford students and faculty start-up companies (ex: HP, Yahoo!), who form great ties with the park and the university. Many innovative ideas created in Stanford found their ways to industries through licensing via the Stanford Office of Technology Licensing. Example include PageRank, Google’s algorithm, was license through Stanford Office of Technology Licensing which is owned by Standford. The 50 or so research centers in Silicon Valley created a link between the industry and the university. They are the link that information about research activities, innovative ideas, recruitment, etc. that industry needed. Also industries provided funding for researches, opportunities of learning for many students. There are a great exchange of ideas and information that provides benefits for industry as well as faculty and students in Stanford. Another great element in Silicon Valley also is the venture capitalists. The great increase of venture capitalists provided many start-up companies the network and financial management they needed. Also most venture capitalists come from the industrial background rather than the finance background. Due to the success of many venture capitalists in Silicon Valley and the expansion of venture capital industry, it attracted other venture capitalists, entrepreneur as well as people with innovative ideas. Therefore, many start-off companies started in Silicon Valley. This also characterizes the network of Silicon Valley.

 The articles also stressed that the duplication of Silicon Valley is impossible without understanding the characterization of the social network. The idea of start-up companies is vital to the Silicon Valley. Usually when a company becomes large and famous around the world, it’s resistance to change due to its past success. Therefore, usually the innovative ideas are sometimes discarded because of what Clayton Christensen calls the “innovator’s dilemma”. The Silicon Valley creates opportunities for those start-up companies to explore and start their businesses based on their ideas while building upon ties with organizations that exist around them. This can also be said about spin-offs. In addition, the NYT article investigates further about why location is a key to many start-up companies. The combination of start-up, spin-off, and large organizations in Silicon Valley create a network of information that favors innovation and creativity. In class, we learned about network with link representing friendship, prices, etc. However, in Silicon Valley, the link represents innovation. No wonder all large technology companies that created iPhone, Google searches, VoIP, etc. are all in Silicon Valley.

In conclusion, the Silicon Valley network is too complex to understand in one day. It contains a lot of histories that need to investigate with the exploration of Silicon Valley network. There are more secrets that need to be revealed to fully understand why Silicon Valley is so successful.    

 References:

NYT: New York Times article featuring why many start-ups companies come to Silicon Valley. http://www.nytimes.com/2007/12/20/technology/20cluster.html?_r=2&pagewanted=all

A Perplexing Economy: describe how Cleveland and Silicon Valley economies are different

http://www.networkweaving.com/blog/2007/12/perplexing-economy.html

Social Networks in Silicon Valley: a paper from Silicon Valley Network Analysis Project (SiVNAP) which describe many natures of Silicon Valley success.

http://www.stanford.edu/group/esrg/siliconvalley/docs/siliconvalleyedge.pdf

http://www.charlotte.com/business/story/497168.html

The article linked to above discusses the use of online social networks to advance one’s career. It mentions how sites even specifically dedicated to social networking (Facebook and Myspace) are starting to be used for professional networking. This is often accomplished through the use of professional groups within the social site.

Aside from the social networks though there are also professional networking sites like LinkedIn and Plaxo Pulse. These can have additional features like LinkedIn Answers which allow you to ask professionals questions in an area that you lack expertise. All of these can be used and made more powerful when analyzed by software from companies including Visible Path, Spoke, and Contact Networks. The software can rank people by how likely they are to yield useful introductions or tell you who can help you get in touch with an executive at a target company.

This shows how people are using social networks to better utilize their current network. The online networks allow people to find the local gatekeeper that will help them get in touch with a desired company or individual, especially using acquaintances, which are mentioned as a key resource both in the article and The Tipping Point. Acquaintances are similar to the weak ties we discussed in class in information sharing networks. Weak ties tend to link people between social groups acting as bridges. These weak ties are to people outside of your social group, making them more likely to have information or contacts that you don’t already know.

http://www.chicagogsb.edu/capideas/jan08/3.aspx

http://www.hbs.edu/research/pdf/08-055.pdf

This is one of the five topics that Ben posted in his blog recently.

How do mutual fund managers of billions of dollars choose which stock to invest in?

The article in the link above and the video in the second link reveal an interesting discovery. That’s right; mutual fund managers turn to their educational network. The research shows that the fund managers invest heavily on corporations which have senior officers who have gone to same educational institution as the fund manager. The strength of the connection varies from being weak to strong; study of weak connection reveals that the fund manager and the senior officer might have went to the same university but different schools with in the university at different time. The strongest connection shows that the fund manager and the senior officer went to the same school with in the same university during same academic years.

The results of the research shows that the investment made from educational netowkr performs significantly better than the investments without any social connections between the fund manager and the senior officer. There are few conjectures as to why the connected portfolios perform better than the non-connected portfolios. First, perhaps there is a strong information flow between the fund manager and the senior officer who can help the fund manager make better investment decisions. Second, the fund manager is able to judge the senior officer in terms of his/her skills, personalities, and capability. If the senior officer seems bright enough, the fund manager will proceed to invest in that specific corporation.

We can relate the result of this research with the concept of homophily in networks. Essentially, what these fund managers are doing is seeking potential investment opportunities from people who are like themselves. Not only did the senior officers of corporations attend the same university as the fund managers but they also belong in the same industry (Finance). There is one more interesting fact that I picked up that might deal with the concept of homophily; whenever a new fund manager replaced the old one, he/she immediately reduced the holdings in corporations that the old manager had and invested heavily into firms that the new manager had connections with. Perhaps, the new manager does not feel comfortable in investing in firms that she does not personally have connections with. Therefore, she, just like the old manager, seeks for potential investment opportunities within her own education network.

Microbiologists would generally agree that the rapid rate at which microorganisms adapt to their environments, and in particular, to antimicrobial agents, is alarming. One may almost characterize the extreme immunity enjoyed of many microorganisms as an opposing army that only seems to get stronger when encountered by our best devices. It may seem frustrating to realize that our best defenses today will only harm us in the long run in the fight against invading microorganisms, but scientists at the Northwestern Institute on Complex Systems are looking to a new perspective to try to find the answers to the question, how to quell the negative influences of invasion. The scientists’ novel approach hinges on their view that the best way to see how microorganisms operate is to see how they influence biochemical pathways. By constructing networks in which nodes represent important metabolites and edges signify key enzymes, the scientists hope to characterize which enzymes are indeed necessary for the opposing microorganisms to utilize, thereby allowing one to narrow the field in the search for potential drug targets.

R. Guimera and M. Sales-Prado, who led the study, proceeded by constructing eighteen networks that featured connections between different molecules and metabolites through enzymes. In analyzing each network, they first sought to see the modularity of each node, or, more specifically, the degree of connectivity a particular node shares with other nodes. In reading their paper, one will see the expression the scientists used to determine such linkages, and they boast that it is the most effective current means of gauging modularity. The essence of such an investigation is to find precisely those nodes that contain many links, in hopes of using the metabolites they represent for therapeutic studies. They also sought to classify nodes according to their roles within a network. Their analyses included several different species, including E. coli and H. pylori, and in addition to their network characterizations, the scientists were also able to purport certain enzymes that are species-specific.

What is significant about Guimera and Sales-Prado’s study is their examination of indispensability: they quantified the degree to which the growth of a particular organism would be affected by the removal of a key enzyme. In doing so, they were able to identify at least a few enzymes are indeed crucial for the particular organism’s development; this revelation offers a potential opening for future, more focused studies.

One final interesting discovery in this paper was that some of the most essential pathways for some key processes in development are supported merely by fragile links. It is interesting to note that the very most deleterious effects of microorganisms may be answered by severing a few fragile edges. With all of these indicative theories on how molecules are related through enzymes, how some enzymes are established in networks, and, perhaps most strikingly, how the application of network theories to the biological world relays significant information on how nature actually works, the door is open to begin to find better therapies.

http://www.pubmedcentral.nih.gov/picrender.fcgi?tool=pmcentrez&artid=2149892&blobtype=pdf

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