Month: July 2003

Woops. I screwed up the NetLogo link in my previous post. Here is the post again, with the link fixed up. I wonder whether I should try editing a post, or whether I’ll just end up deleting my whole blog again…

I just downloaded NetLogo – a modelling and simulation environment. With it, I hope to create a very high level model of my original, ant-based service discovery protocol. NetLogo comes with a whole array of models which you can run, and the user community has created a bunch more. I want to create a high level model for the benefit of the complex systems researchers around the place, who may know little or nothing about pervasive computing and service discovery. It would be excellent if I could get those guys thinking about pervasive computing environments as an interesting domain that bears further study. This simulation won’t be for the benefit of computer networks and distributed computing people, who most likely aren’t too bothered with these high level models. I’m making sure I have one foot in complex systems territory, so that I can branch in that direction if I want to once my Ph.D is complete. For me, the lure of complex systems is its application to a wide array of fields, or rather, the fact that complex systems are everywhere: computer networks, sociology, economics, physics, biology – everywhere! Potentially, this means one should never be bored studying complex systems. But I fear this is a gross misaprehension, as those actually studying complex systems are all too willing to tell me.

But right now I need to focus on writing that paper with Ted, and thinking more about aggregating service discovery domains. Here’s a problem that might or might not have a simple solution. If distinct groups of p2p devices are connected hierarchically, perhaps based on physical location, how does a service at the bottom of this hierarchy know how widely its service description should be advertised? That is, a service at the bottom can know nothing about the overall topology of the network, so how does it specify how far up the hierarchy its service description should be advertised? As a contrived example, imagine that all the services on one floor of a building form a p2p group. The next level up is the building, then the campus, then the city and so on. A printer service wants to advertise itself to the entire building, but how does it do this, given that it can’t know, a priori, the way the p2p groups are split up. In its service advertisement message, it could say “advertise this to the building level domain but no higher”, but it would only be guessing that a there is such a thing as a building level domain. The topology could be organised using any other hierarchical property. I haven’t thought about this too deeply yet, but hopefully the solution is not difficult. Of course this assumes we even want to introduce hierarchies of p2p groups into the model. This may break the scalability of the protocol altogether.

For non-computer scientist readers of my diary, I apologise for waffling on about all this technical stuff. But there are a couple of computer scientist friends of mine who’ve indicated their interest in what I’m doing at uni and how my ideas are evolving. Besides, I’ve found it very helpful to dump my ideas in here. Looking back over my diary, there is a definite pattern emerging relating diary entries containing my random ideas and my level of productivity in the days and weeks following. On at least two occassions, random thoughts dumped in here have culminated in a manuscript, one of which has been accepted to a conference, and the other which is currently undergoing a review process. If I hadn’t stupidly deleted all my entries before March, I’m sure I would have observed a flurry of Core Dump activity in the lead up to my confirmation seminar too. So it seems that I can use this diary as a first step toward getting something accomplished, and I’m hoping this continues to be the case. So, unfortunately for some, the boring technical stuff will continue to appear in here. You can always skip reading it anyway.

Ultimately, this diary is forme to look back on, even if I do write a good portion of it for the small readership it has acquired. It should go without saying that my most personal thoughts and any incidents I wish to keep private don’t make it onto these pages. Apparently, that point was not entirely obvious. I can be candid, but not that candid! If you want more than I’m giving you, well you can always go and watch Big Brother (a show that I detest, by the way) or something like that. This is a Bowdlerised version of my life, because I don’t think everyone wants to know about every single one of my highs and lows, or what I think about these luxury Japanese toilets ;). More to the point, I don’t want everybody to know the ins and outs of my life! That was never the point of this diary. Those of you thinking you can read this blog to get an accurate indication of my state of mind on any particular day are sadly mistaken. You know who you are :). Just a friendly piece of advice. But do keep reading! :)

I just downloaded these luxury Japanese toilets ;). More to the point, I don’t want everybody to know the ins and outs of my life! That was never the point of this diary. Those of you thinking you can read this blog to get an accurate indication of my state of mind on any particular day are sadly mistaken. You know who you are :). Just a friendly piece of advice. But do keep reading! :)

During the past couple of weeks my productivity has taken a slide. To combat this, I’ve asked Jaga for more regular meetings. I also find that having to take tutorials during semester actually helps my Ph.D productivity in some ways. Teaching once a week puts my brain in gear, and it acts like a kind of heart beat that gives my academic week some sort of rhythm. I’m also attending a seminar series on Complex Systems this semester, which should help a bit further. Given the direction of my thesis, it should also be very relevant. The seminar series is actually just the lecture component of a computer science subject, but it was widely advertised to academics and post-grad students in case they wanted to attend. The first lecture was yesterday, and it covered some very introductory material on complex systems and complex networks in particular. At the moment, my mind is too free to wander, but these more regular appointments should put an end to that.

The antenna guy came, noted that the main problem with reception was ghosting, and said that we should just buy a digital set-top box because the ghosting would go away. Only SBS might cause some problems. He noted that eventually we have to buy a set-top box anyway, because the analogue broadcast will be switched off completely in a few years.

Had a bit of a BBQ today, attended by my housemates, my cousing Terry, Boggo and SEM’s friend, Valentine, who is staying with us for a few days.

Last night I went clubbing with Nigel and Terry. We intended to go to Level 5, but there was some kind of special event on (a singer) that we weren’t interested in. So we walked around a bit, collecting two-for-one cards, and eventually decided to check out The Vibe on Elizabeth St. It was pretty lame, but to be fair it was still early. We probably got there at 9.45pm. But we had are few rounds of two-for-one Bourbon and Colas and left. They were using Old Crow Bourbon, which didn’t make things much better! The best part about The Vibe was that we recalled a very funny story (funny for us, but not for anyone else: it was a "You had to be there" story) from a party we had in Caloundra several months ago. I crack up completely every time I think about it. We spent the rest of the night at the Stock Exchange. Danced the night away, and had a lot of fun. But I am slightly deaf in one ear. There were a few techno type tracks that were played entirely too loudly, and simply had the effect of making everyone on the dance floor cringe and stick their fingers in their ears. We got home at 4am in the morning. I’m very tired as I sit here typing this. :)

It’s quite cool at the moment. So cool in fact that I felt it necessary to turn on the air conditioner to warm the house. It’s probably only the third or so time we’ve used the air conditioner this winter.

Finally, after about three months of non-correspondence, SU decides to e-mail me. It was nice to hear from her again. She does seem very busy, and so It’s probably a bit selfish of me to expect to get regular e-mails from her. However, after – holy crap, it’s been almost two years – almost two years of frequent correspondence I think it’s fair that I was wondering what had become of her when I heard nothing from her for a few months. Anyway, she did apologise profusely for not replying sooner.

The BBQ that I hastily arranged for Sunday will probably be a fizzer. The guest of honour :) has to go meet his grandparents on Sunday now. For most of us, it’s not everyday you get to see your grandparents, especially if you live at opposite ends of the country. I’ll probably still just have a couple of the boys around. The guest of honour can come around for dinner next week some time instead, before he heads back down to Melbourne.

Phoned the plumber to see if he could come around and fix the flush on one of the toilets. We have a rather uncommon model of loo, so it turns out it will take some time to order in the correct part for the flush mechanism. There’s a little hook thing that joins the flush mechanism to the buttons on top of the cistern. The hook snapped clean through. I also called Mr Antenna to arrange a consultation. He (or rather a representative from Mr Antenna) is going to come around on Monday morning. Really all I need is a signal detector so that I can locate the best position for the TV antenna on the roof, and to test whether we can clearly receive the UHF frequencies that the new free to air digital television channels use. There are some rather large fig trees between my house and Mt Coot-tha (where the TV stations broadcast from). They absorb a good portion of the TV signal. Also, the signal bounces off the next door neighbour’s roof, which causes a double image effect on some channels. The trees might pose a challenging problem if I ever get around to setting up a Brismesh node. IL, another famous non-corresponder by the way ;), says he’s going to attempt to install a wireless access point on top of GP South. I might almost have line of sight from my house to the roof of GP South if I aim the microwave underneath the trees’ foliage. Brismesh may be a useful test bed if I ever get my service discovery stuff completed, so I ought to participate in Brismesh meetings and so forth, I think.

Today I wrote out my ideas about how to aggregate multiple separate distributed hashtables. I think I have a workable and scalable solution, but it’s time to go to sleep, so I’m not going to explain it now. Actually, it was time to go to sleep an hour ago…

Today I read a paper entitled Data-Centric Storage in Sensornets. It suggested a way in which distributed hashtables could be used on top of a geographic routing protocol (GRPS) in sensor networks to make more efficient use of bandwidth and lower energy consumption. This work is quite interesting, and relevant in terms of my own work. If nothing else, it has provided legitimacy for one of the scenarios I invented for my service discovery protocol. Namely, there are applications in which notifications are produced by the sensors at frequent intervals. These notifications can be thought of as resource descriptions which can be stored and queried. One of my protocols, Superstring, performs best relative to other protocols when the average time between advertisements is less than the average time between queries. The applications described in this paper would seem to match that profile exactly.

But other than reading the paper, I didn’t get much done. I spent a long while helping a student build SFSnet under Solaris without much luck. I really need to get on with my Ph.D and finish writing this paper with Ted. But Ted is understandably very busy at the moment. Honestly, I just need to complete my model for service discovery and then implement a prototype. There are a few issues I’m still to sort out. The main ones are scoping advertisements and queries, and heterogeneity. The latter also involves figuring out how to add the concept of peer-groups to DHTs, or from another point of view, how to merge one group of devices with another in a scalable fashion. Think about a sensor network which is linked to a wired network such as the Internet. Is it sensible to make the two sets of devices (sensors in the sensor network and computers on the Internet) part of the same flat routing space? As I see it, these are the two problems I have left to solve before I can start implementing a prototype.

I’ve been listening to an album by the Australian hip-hop group The Herd quite a bit recently. It’s called An Elefant Never Forgets. I’ve grown away from hip-hop in recent years, but The Herd is definitely growing on me. The background melodies are pretty funky, and each track has a different sound. The lyrical sound is not that great (somehow the Aussie accent just doesn’t quite do it for me), but the lyrics themselves are politically charged and deal with contemporary Australian issues, which suits the hip-hop genre to a tea. I still pull out the Warren G on occassion too. But boy it feels like ages since hip-hop was the sound for me, and the baggy red 3/4 shorts and the ill-fitting cricket hat were the clothes for me. I guess it has been over five years since first/second year uni :). Maybe I’ll pull out the old get-up one of these days for old time’s sake. The UQ bucket hat I’ve got now is a nice replacement for the fake bucket hat (the tight cricket hat that looked like a bucket hat ;) that I used to wear. Then again, perhaps it would be best to leave that stuff in the closet. Yes. But they were good times. Not good times academically, perhaps, but good times nevertheless.

Last night I enjoyed a delicious dinner at Ben’s parents’ house. Ben heads back to Canberra today. I’ve got Dave Jensen’s e-mail address and phone number, so I have someone else to practice Spanish with.

I’ve been given the task of reviewing another three papers today. They appear to be of a higher standard than the previous paper I reviewed. But this is not a good sign from my point of view, since my paper is competing with these ones.

In other developments, one of my colleagues, whom we shall call George, seems to have been swallowed up by a black hole or something at around lunchtime today. George was a bit cross about something or other, and went for a walk, or so I assumed. But George did not return. At least George hadn’t returned when I left the office to get a haircut at 5pm.

Which brings me to the next development. I went to the hairdresser today, and had a lot of hair removed, although only the very observant will notice. My mane is still as long as it was, but not as thick. My head is still as thick as it always was. :)

When I got home this evening I read ABC news as I usually do, and found this story about some research that suggests eating pizza on a regular basis could reduce the risk of contracting various kinds of cancer. The research, funnily enough, was performed by Italian scientists. Hmm. Nevertheless, guess what we’re having for dinner tonight!

My weekend started on Thursday evening, really. I suggested that we (my housemates and I, as well as my cousing Terry) should have dinner and coffee at The Three Monkeys Tea and Coffee House in West End. It’s one of my favourite little cafe’s. It has a very distinct atmosphere, which I like very much, and the food and beverages are excellent. We whiled away a few hours just sitting and chatting. I decided to stay at home on Friday, because there were a few things that needed doing before heading up to Caloundra for Mum and Dad’s wedding anniversary/Dad’s birthday. I mowed the lawn, trimmed the edges on the footpath and the gutter at the front of the house with the old fashioned trimmer, washed the car and did some ironing. But before all this I dropped Nigel off at his office in Kedron, which in rush hour is about 40 minutes each way. Then I went to the local nursery and picked out a plant for Ben and Marice’s new property north of Gympie. I ended up choosing a Grevillea after the nursery lady confirmed this would be a good choice. If only I could be this productive everyday!

I then headed up to Caloundra, remembering to pick Nigel up on the way. My grandmother, uncle and my mother’s cousin from Melbourne were already there, and Mum had prepared a nice Indian dinner. We handed over the CDs and the anniversary/birthday card, which were appreciated, even if the CDs were not a complete surprise. Much of the night was spent talking tech with my uncle. He’s trying to set up his computer with two separate, swappable disk drives, so that his daughter (my cousin) uses one disk, and he uses the other. I politely suggested that this was not the smartest way of doing things and that using file permissions was a better way to achieve the same result. He also wants to learn how to crack into computers for various reasons I won’t divulge here.

On Saturday I headed further north to the bustling town of Gympie. More accurately, I drove through Gympie to the outlying town of Chatsworth in order to help warm Ben and Marice’s new block of land. The landwarming also served as a kind of old boys’ reunion of sorts. Rhys kept us entertained with stories about his five month long backpacking trip through Europe and Thailand. There was also much to chat about with Ben, since we Brisbanites don’t get to see him that often any more. I also scored an Australian soccer jersey from Rhys, which he’d bought in Thailand. It’s genuine, of course ;).

I ended up getting to Chatsworth rather earlier than I had planned. Gympie is not as far from Caloundra as I remembered. It gave me a chance to have a chat with Ben and Marice before the others arrived anyway. I arrived at Marice’s family’s house at twelvish. I was re-acquainted with Marice’s family whom I had met previously at Ben’s and Marice’s wedding. Marice brought along a friend and colleague, whose name I’m not sure how to spell, so won’t attempt to :). Seemed very pleasant, but didn’t get to talk too much. As I said, it felt very much like an old boys’ reunion, so there was heaps of catching up to do with the fellas. I didn’t even get to test out my Spanish (she’s from Nicaragua, so speaks Spanish of course). Actually, I’ve gone many weeks without speaking or writing any Spanish at all, and I know from previous experience that even a short break of this length has a serious detrimental effect on my spanish vocabulary. At this early stage of learning, I’ve really just got to force myself to do some spanish every week. Classes recommence next week, so I should do some study before then. But I digress… Once everyone had arrived, including Ben’s parents whom I hadn’t seen since the wedding, we piled into a few cars and drove over to Ben’s and Marice’s selection. And a fine selection it is. Nice views looking westish over farmland. The bottom of the block falls away steeply, so there were suggestions that Ben should build a flying fox or water slide down the hill. You could also easily launch a hang glider I reckon. After lunch, we planted some trees. I have some photos and a video clip or two which I will put up on this web site when I get the time. The video of Ben digging a hole is a classic… It was a very nice hole ;).

After some afternoon tea back at Avonmont (Marice’s family’s home), it was back to Caloundra. The day was capped with a nice game of Quizzit – a new Trivial Pursuit type of thing – with Mum, Dad and Nigel.

Today, Nigel and I took Mum and Dad on a drive around the countryside. We took in Point Glorious Lookout, Cooloolabin Dam, Wappa Dam and Cooroy Botanical Gardens. A very nice day out, and a lot of driving along unsealed roads. The Barina bottomed out once where the road was just too rough for it, but no damage was done. A very, very nice day out. But I still feel like there’s heaps to explore up there, even after all the little drives we’ve done recently. Now Nigel and I are back home at Fairfield.

I’ve done a great deal of driving this weekend. But I enjoyed all of it! I even obeyed the speed limit on the highway returning home tonight. As evidenced by the size of this diary entry, it’s been a packed few days, and I thoroughly enjoyed every single moment of it.

Ben’s parents have invited us fellas around for a BBQ on Tuesday evening. Now I just have to remember their address. I should have it somewhere.

Completely switching topics, the Aussies wrapped up the first Test against Bangladesh. Bangladesh put up a bit of a fight in their second innings, but Australia won by an innings and a hundred and something runs. So, Darwin have had their first ever Test match, and Steve Waugh becomes the most successful captain ever, overtaking Clive Lloyd in terms of the number of matches won as captain. Steve Waugh also became only the second player to score a century against all nine Test playing nations, and has scored the second highest number of centuries (equal with Tendulkar, but behind Gavaskar). I’m not the biggest fan of Steve Waugh because of his win at all costs mentality and his propensity not to walk even when he knows he’s out, but he deserves congratulations for reaching these milestones.

And in the best news of the day, Frank Lowy is the new Soccer Australia chairman, and John Singleton and Ron Walker join him on the board! Apparently this happened on Saturday, but I haven’t been watching the news much this weekend. This is fantastic! Finally!