Trustworthy News Model Assumptions


  • 12.13.16: Initial post
  • 12:16:16: Added reference to proposal and explicitly discussed explorer and exploiter types.

A web version of my Google Docs dissertation proposal is here. Blame them for the formatting issues. The section this is building on is Section 5.3.1. A standalone description of this task is here.

The first part of my dissertation work is to develop an agent-based simulation that exhibits information bubble/antibubble behavior. Using Sen and Chakrabarti’s Sociophysics as my guide, I’m working up the specifics of the model. My framework is an application (JavaFX, because that’s what I’m using at work these days). It’s basically an empty framework with a trivial model that allows clustering based on similar attributes such as color: strawmanapp

Going forward, I need to clarify and defend the model, so I’m going to be listing the components here.

Agent assumptions

  • Agents get their information from global sources (news media). They have equal access, but visibility is restricted
    • Agents are Explorers or Exploiters (Which may be made up of Confirmers and Avoiders)
    • Agents have ‘budgets’ that they can allocate
    • Finding sources has a cost. Sources from the social network has a lower cost to access
    • Keeping a source is cheaper than getting a new one
    • For explorers, the cost of getting a new source is lower than an exploiter.
    • The ‘belief’ as a set of ‘statements’ appears to be valid
    • The collection of statements and the associated values create a position in an n-dimensional hilbert space of information. Position and velocity should be calculable.
    • Start at one dimension to reproduce prior opinion models

Network assumptions

  • There are two items that we are looking for.
    • The first is the network configuration over time. What nodes do agents connect to for their information.
    • The second is the content of that information. For that, we’ll probably need some dimensionality reduction, such as NMF (look for a post on implementing this later). This is where we look for echo chambers of information, as opposed to the agents participating in them
  • Adjustable to include scale-free, small world, and null configurations
  • What about loops? Feedback could be interesting, since a small group that is semi-isolated could form into a very loud bubble that could lower the cost of finding information. So a notion of volume might be needed that emerges from a set of agreeing agents. This could be attraction, though I think I like an economic approach more?
  • There is also a ‘freezing’ issue, where a stable state is reached where two cliques containing different states are lightly connected, but not enough that the neighbors in one clique can be convinced to change their opinion [Fig. 6.2, pg 135]


  • Residual Energy: The difference between the actual energy and the known energy of the perfectly-ordered ground state (full consensus).
  • Deviation from null network.
  • Clustering as per community detection (Girard et. al)

Implementation details

  • Able to be run multiple times with the same configuration but different seed
  • Outputs to… something. MySql or Excel probably
  • Visualization using t-SNE? Description plus Java implementation is here:

More to come as the model fleshes out.



Standard programming mysteries.

I hate it when I’m starting off with an API and the tutorials don’t work.

I was working with the LWJGL OpenAl examples described in earlier posts, and could not get the audio files in the examples to open. The file was there, it could be converted to an InputStream, but when I tried creating a LWJGL WaveData object, the underlying java audio code would throw an error and I’d get a null object.

So since I’m now trying to figure out what gives with the javax.sound.sampled.* system, I might as well see if I can do what I want to do here. So off we go to the Internet once more, looking for examples that work.

The first thing I found was the Oracle Java Sound API documents, which are huge, loaded with theory and very little code. I’m not complaining really, because they look like they will be really useful when I have a little bit of code working. But there needs to be a “Hello, World”.

Which showed up after a bit of searching. There is a website JSResources, put together by two German (?) developers; Florian Bomers and Matthias Pfisterer. It is loaded with examples that seem to work. I’ve just gotten one of their simple examples running with a minimum of fuss. (Here’s the (slightly) modified code).  Since this is straight sound library, we know that we can run all the channels. Now we just need to get from here to there.

Wireless. But in a bad way.


I got my amp (2 channels) and USB Dolby 7.1 adapter from Amazon last night and wired up the transducers this morning, hoping to make some vibrations this evening. However, I forgot that I needed to get the sound *from* the Dolby unit *to* the amplifier. Oops. Looks like a trip to radio shack tonight. And no work on this tomorrow, since I’ve got class.

Sigh. With luck, Friday.

Sorting out 3D Sound Libraries

Being a creature of habit, my thought was to go to J3D and use their api, which is quite nice, though essentially unchanged since 2000. It was split off of the main development line when Oracle came in and was then moved off to – more specifically,

Since I have the “The Java 3D API Specification 2nd ed”, I downloaded the latest version (1.5.2) and installed it, pulled out the audio examples from the book’s CD (I know, how quaint), loaded everything into eclipse and built the three examples and their support classes.

Things were not happy when I tried to run though. I got an error saying that I shouldn’t use the 32 bit libraries on a 64 bit machine. Problem is, I have an Intel chip and the dll is for AMD chips. So I uninstalled the 32 bit code and tried out the 64-bit. By golly it compiles and runs. The only problem is the following:

java.lang.UnsupportedOperationException: No AudioDevice specified
	at com.sun.j3d.utils.universe.Viewer.createAudioDevice(
	at SimpleSounds.init(
Java 3D: audio is disabled

Now, I know I have audio on my gaming-level development box, so that’s disturbing. This forum post looks promising. I’ll give that a try tomorrow. Failing that, I can go to the LWJGL, which has hooks to OpenAL. That appears to have more activity, and I like the LWJGL folks, they write good code. They even have tutorials!

In addition, I’ve ordered a Vantec USB External 7.1 Channel Audio Adapter, and an Audio Mini Amplifier to try hooking up various sound sources to my collection of tactile transducers from Parts Express.