Research

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Asterisk Sound Problem

I have spent nearly two hours trying to figure why I get no sound when I do a console dial on Asterisk. I was getting the error ‘Unable to re-open DSP device /dev/dsp: Device or resource busy‘. As far as I was concerned my sound card was not being utilised by any application so I figured Asterisk was acting up on me.

Well I guess I was wrong. The soft phone (Egika) which loads immediately after booting was in fact the culprit. I quit the application. It is should be noted that there is a vast difference between quit and close in the context of the application, so using the cross (X) on the Egika window is not what one wants to do. After quitting I loaded Asterisk followed by Egika and both worked as expected.

I am satisfied with finding the cause of the problem but I am still curious about why Egika acts so possesively. The application uses an ALSA plugin and I thought the whole point of this sound architecture was to promote selfless and not possessive behaviour from applications using it! May be I am just annoyed orthere is something I am missing!!

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Behavior Change Communication

On Thursday, I sort of told Lorenzo (one of my supervisors) that I tend to stray a lot while in cyberspace. To my defence, the internet is such a huge huge place and it is pretty difficult even with best intentions not to stray. Anyway, whilst I was straying I came across an interesting article on Behavior Change Communication (BCC) for HIV/AIDS from the Family Health International (FHI) site.

First things first, what is BCC? Quoting verbatim, BCC is:

” a multi-level tool for promoting and sustaining risk-reducing behavior change in individuals and communities by distributing tailored health messages in a variety of communication channels.”

So in the context of HIV/AIDS, BCC is about tailoring messages that will help in the prevention of this disease. In tailoring messages, BCC advocates development of a strategy that will create a demand for information and associated services. The essential steps in creating such a strategy is quoted below:

“The following steps incorporate careful analysis, feedback and redesign throughout the entire process. Step 1: Identify the problem based on the overall program goals. Step 2: Segment target populations. Step 3: Engage in formative research. Step 4: Identify behavior change goals. Step 5: Seek consensus from stakeholders.

Step 6: Design communication plan, including objectives, overall theme, specific messages and outlets for dissemination. Step 7: Pre-test and revise. Step 8: Target communication to specific groups. Step 9: Implement the plan. Step 10: Monitor and evaluate it. Step 11: Seek feedback and make appropriate revisions.”

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Ontology as Part my Journey – Part 2

As I continue with my journey on use of ontologies, I decided to explore some of the tools that can be used in the development of ontologies. I have long decided to use Protege but I thought there is no harm in exploring what is available. I began my venture but like the good woman that I am, I decided to exercise the right to change my mind.

What served as a trigger for the change of mind was a random mention of Cyc in one of the articles I was reading. It wasn’t the first time I came across it but this time I thought to self: ‘about time you explored this!’ So with obvious determination, I proceeded with my exploration! This yielded fruitful results in less than 30 minutes (with the help of Google of course).

In 30 minutes, I was lead to believe that OpenCyc might be useful in helping me to model my HIV/AIDS ontology. As aptly put, OpenCyc can be used for “rapid development of an ontology in a vertical area“. What this means is that OpenCyc is ideal for developing ontologies in a specific domain. (Go here for more on vertical and horizontal ontologies)

This is literally good news since one is always adviced to avoid building an ontology from scratch – if possible! And I was almost under the impression that this is the route I may have to follow. ( I boldly told my supervisors not so long ago that ontologies related to HIV/AIDS for disseminating information to laymen are not available. ) Well I am yet to download OpenCyc and may be I might need to retract my statement. I shall cross that bridge when I need to, right now I am just happy I have an excuse to celebrate my Friday. (Of course, I don’t really need an excuse because every Friday is a good Friday 🙂 !)

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SATNAC Submission

I submitted my work in progress paper to SATNAC and I am pretty happy. I have been told that part of the exercise in writing a work in progress paper is to get practice in academic writing. I think I am growing from the experience but I am certain I don’t like red writing. I haven’t really verbalised this to Alf but for some reason he seems to have figured this out. All my feedback unlike with the proposal was in GREEN. I hope it wasn’t a case of him not having a red pen, but if it is (and hopeful he might read this) green is the way to go for aspiring tree huggers like myself.

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Ontology as Part my Journey – Part 1

Ontology use in the context of this research is beneficial in that it allows knowledge sharing and re-use. Although reuse may not be a challenge in this research as we will be modeling our ontology from scratch, it is important to ensure consistency. Without consistency, extendability of our ontology may be compromised; in a sense that it may be difficult to reuse.

Some important questions related to reuse include:

  • How the changes will be handled.
  • How versions of the ontologies will be related.
  • How to store ontologies.
  • How to identify and retrieve ontologies.

Central to these questions is the problem of harmonising the concept descriptions. For example, consider building a taxonomy that will be used to capture the statement” ‘HIV/Aids is an infectious disease that is not curable‘. With this in mind, which of these two is more preferable?

Right now I cannot say which between the two is better, but if at all one is better then it means there are good and bad ontologies. This is something to explore (but certtainly not today)! The point for today is simply to suggest that the two demonstrate that the challenge lies largely with the conceptualisation of the intial model; since to maintain consistency one depends mostly on initial modelling decisions. Further, idea of re-use of an ontology cannot be taken for granted even though it is one of the most cited reason for using ontologies.

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What is ontology?

Ontology is not a new concept. It is a century old concept, with roots from philosophy. However, the Semantic Web has popularised this concept (so many are forgiven to assume that this is new). But more to the point of this post, what is ontology?

In computer science, the classic definition is provided by Gruber. He defines ontology as a “specification of a conceptualization”. This definition although widely accepted some critics say it is too simplistic and incomplete. At the heart of this criticism is that Gruber’s definition reduces ontology to a model in people’s minds instead of a model that is representative of the universe that constitutes the domain.

I will try to explain what I think the critics say: in a nutshell, the argument being made is that ontology is much more than the concepts as understood by people in their own heads. Ontology needs to reflect completely the world of the domain being represented. To perhaps clarify this point of view, I imagined trying to see life through the eyes of an extremist (political or otherwise). To me, an extremist cannot possibly represent true reality of ‘what is’. Therefore, an attempt to reason about the world from that point of view would be doing the world injustice; since the vision of an extremist at best of times is not “true-to-the-world”.

My explanation may of course be a bit philosophical but as said before, ontology gets its roots from philosophy. Now, going back to Gruber. He does explicitly suggest that ontology pertains to modelling of knowledge of some domain be it is real or imagined. Further, he does insist that the modelling is as formal as specifying a program.

In conclusion, while the critics suggest that Gruber’s definition reduces an ontology to be seen as a mere “ad-hoc model built for some specific purpose”. I think I believe in Gruber’s definition for it is short and sweet (like me ) but also very open to interpretation. One possible intepretation is:

Ontology is a formal specification of conceptualization.

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Using Technology to Bring About Social Change

In my last post (over a month ago), I was more or less using photography for inspiration. I am not a photographer. However, I am a habitant of the technology world (but neither a geek or a technophile) and as such, I have a duty to advocate for the use of technology in bringing about social change. Today, by some fluke, I came across a blog on “How to Use Social Media for Social Change“. This blog moved me in almost the same way the photograph by James Nachtwey moved me. When I saw that photograph, one of my first impressions was: ‘something needs to be done; the man is practically walking next to his own shadow but in fact he is himself a shadow of his former self because of HIV/Aids’.

I derailed a bit, the point is, we members of the tech community need to rise to the call! We need to do something to bring about social change. We have a responsility to ensure that people don’t die due to HIV/Aids; lack of clean water and sanitation; hunger; etc.

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Corridor of Death

A picture is said to say a thousand words. Below is a picture that resonates so much with what we would like to prevent – people moving into the corridor of death by Aids. This picture was taken by a renowned photojournalist and war photographer, James Nachtwey, just two days before the man met his fate. Looking at it from this context, I hope it is easy to see why the words “corridor of death” are associated with the picture. Further, I hope that this piece of fine art evokes enough emotion to cause each one of us to participate in the fight against HIV/Aids.

James Nachtwey's work


 

For true admiration of the original work visit James Nachtwey’s gallery .