Today, I read that Edsger Dijkstra has died from cancer.
In a short autobiograpgy (EWD1166), I read that he constructed
the algorith for finding the shortest path in a directed graph
without paper and pencil. As far as I can recall, I also found
the algorith (independently) without paper and pencil. I vaguely
remember that I was sitting in the train.
I implemented it in LISP.
When searching for his name, I did find
an interview that appeared in a Dutch newspaper.
(He died on August 6)
An overflow in the attic
When we bought our house, we were very happy with our large
and empty attic. Next Tuesday our new bed is going to arrive.
We decided to give our bed to Annabel.
Yesterday, I took apart
the two beds that were in her bedroom. One of the beds was used
by my mother-in-law earlier this year. Then we discovered that
there was not much room in the attic. Yesterday, Li-Xia also
decided to empty some of the cupboards on the sides of the
attic to see if we could put in some other things. So, this
afternoon, I found myself in a completely full attic with the
assignment to store-away some stuff and to make room. I have to
admit, I became a little depressed not knowing where to begin,
and what to keep and what to through away. On top of that I
also found some boxes with old letters, bringing back many
memories from the past. After about six hours of hard work,
we managed to clear away most things and to put our bed in
the room of Annabel. To night we will be camping, sleeping on
the matrasses on the ground. How romantic.
(follow-up and
giving Annabel's bed to Andy)
Saturday, I bought the video of Lord of the Rings: the
fellowship of the ring. After having watched the first
half that evening (till the fellowship left Rivendel),
we watched the second part yesterday evening. In bed I read
through my copy and found several inconsistencies, and I
wondered how many there are.
Today, I found
a page describing many differences. I also found
a page with the script of the movie.
Students
This week the freshmen students have their introduction
period. Yesterday, we already saw some strange vehicels
pass by out office. This morning, we saw many students
collecting some kind of wooden pallet, which they might
need for the pond race. The weather looks okay for this
kind of event.
Scaffolding
Yesterday, some people build up a
scaffolding in the
hall of the KTC building (where my office is). Today,
I heard it was because some lamps in the ceilling needed
to be replaced. It seems it is not tall enough for that
purpose as you look at the picture on the left that I
took this after noon. Nobody has been doing anything
today with the scaffolding. Should I send this in as
another "How do .. change a lightbulb?" riddle?
Personality tests
Yesterday, Li-Xia received the
results of some personality test she did. It was a
Holland's
personality test, which recognizes six different types of
people. Each of the six types matches up with a certain type
of job. Looking at the types, I think that I would score
high on the investigation type. I found some other
intersting personality tests. A very simple one, I encountered
consisted of picking a image from nine given images. I selected
this.
Of course, I also looked at the world famous sixteen.
Myers-Briggs personality types. I think, I fit the
INTP type
the best, although, I also might be a INTJ. I did not
find a table comparing the Holland's personality types
with the Myers-Briggs'. I did find a page about the
Five-Factor Model of Personality, which simply states
that the traditional Myers-Briggs division in sixteen
personality types is wrong. Looking at these, I think,
I am an O+, C+, E-, A+, N+, although I also could be in
the middle for the C and N factors.
This morning, Annabel said that
there was a spider on the wall of our living room, "a big
one" she added. And indeed, it was not a very small one.
We tried to catch it, but it escaped under the sofa and I
did not want to continue the search. Late this evening,
I spotted it on the wall again and was able to catch it.
I am not very afraid of spiders, but the idea that a big
one might be creeping on me while I am in watching television
is a bit scary to me.
Again an example of a social pattern rather than an architectural
pattern. Only when learning goes by the manner of master and
apprentices, the workplace needs to be organized as such. One can
raise the question why nowadays learning and teaching is mostly
done in specialized institutions (such as universities) rahter than
as part of work. I agree that each working experience should also
be an opportunity to learn, but I do not think that a master-apprentices
relation is always needed for this. People
working in pairs can learn from each other, even if the are on
equal level.
Boring fractals
Fractals are known for their unlimited amouth of detail. No matter
how much you zoom in a fractal, it will always show more details.
Some weeks I ago, I installed JuliaSaver as my screen saver. The parameters I am using are:
- Fractal tab: Type: Julia, Iteration: 256, Resolution: Lowest, Animation Trails: Highest
- Mapping tab: Type: Inverted, Allow rotation: on,
Allow center to move: on,
Rotation: 37.5625, 2.5, 9.8125, 2.5,
Real: 7.5, 2, 6.4375, 1.667968,
Imaginary: 1.625, 1.667968, 9.5625, 3.33203.
- Animation tab: Type: Cardioid Trace II, Speed: lowest,
Real: 9.125, 1, 23.375, 1,
Imaginary: 7.0625, 1, 17.3125, 1.
- Color tab: Random, Color Inside: Off, Stretch Pallet: On.
And although this produces very interesting moving
fractal images, it slowly becomes more and more boring.
Artificial brain
Last week, I came across some articles about home made
robots. This made me think about a selflearning robot
with an artificial brain. Today, I found
a good introduction to neural networks. I also
found some detailed description and visualization of the
Nervous System of
the Drosophila Melanogaster.
A lot of research has been done with respect to
neural networks, but most of the research deals with
simplified neural networks and how to teach these to
map certain given input signals to desired output signals.
This kind of neural networks first go through a training
periode, and once they have been trained they are put
into execution, during which they do not "learn" anymore.
This can hardly be called selflearning, as with selflearning
the network itself would decide when it needs to learn and
when to execute previously established patterns.
There can only be learning, in case there is stimulus
for change. In case of an artificial brain on a small
robot, there need to be sensor. The signals from these
sensors are the input for the neural network. The output
of the neural network should control the motors that
make the robot move around. There should be some kind
of judging function whether the input signals are pleasant,
and the neural network should be stimulated to change
itself when the signals are not pleasant. Examples
of unpleasant stimilii are bumping against something
and having a low battery power. These could be
compared with pain and hunger signals. A hunger stimilii
is only interesting if there is also an opportunity to
eat, e.g., to have the batteries recharged. And, of course,
the feeding place should be recognizable in some sense.
Being recharged should be a pleasant stimilus as long as the
batteries are low. To motivate the robot to move around,
one could define something as boredom: not sensing any
changes in it visual sensors and not hearing any sounds.
(To be continued.)
I do agree with the conclusion of this pattern, but
I do not understand the reasoning behind the difference
between natural and artificial light. I think, that
the main reason why people feel more comfortable in
rooms with windows, is because it gives them the
(potential) ability to look outside. In the Netherlands
there is a regulation that offices were people work,
should have windows. I remember that in one of my
previous working places we had a meeting room with no
outside windows. It was called the "white room" because
its walls were white. Funny that it was called like
that.
"The Three Sirens"
In my search
for the application of neural nets in
selflearning robots, I came across
"The Three Sirens", a group of music making
robots. Sounds very interesting, but I could not
find any information about the exact algorithms being
used, except that it is a "variant of the so called
Self Organizing Maps (SOM)".
(follow-up)
Sometimes, I come across programs that I had thought about
myself to write. Today, I found one. It it the program S-Spline
that can enlarge pictures without loosing sharpness. Check it
out, it can do some amazing things. Sadly, it is a little
expensive, and they claim to have patented the technique.
(follow-up)
Lost in the past
There were still
some things to be rearranged in the attic. And that
meant moving out some things first. By doing so, I came
found some old papers, and decided to throw away some of
these. Instead of throwing away, I found myself reading
through all those old papers and remembering many things
from the past. And, of course, I felt like keeping all
those letter, documents, and such, instead of throwing them
away.
I have been considering to scan them and only keep
them in digital form. But, I haven't found a good way to
quickly scan documents. A traditional scanner is too slow
and the quality of a cheap digital camera is too low.
The Jedi Faith
It seems 70,509 people have reported to be followers of
the Jedi faith in Australia. However, by the Australian
Bureau of Statistics they are categorized as "not defined".
Those people must be disappointed, and they could be
charged a fine.
Andy made a
painting
for Annabel.
The succes of any virus (biological and computer) greatly depend
on the opportunities that the host gives for spreading it. A virus
that is not succesful will die before it will have become broadly
known. In this sense the success of a virus says a lot about the
host. This is also true for computer virusses. SO the title should
have been "New worm provides sad snapshot of the average internet
user psyche". I could well be possible that there is a large group
of virus writers who create very unsuccesful virusses. One could
also conclude that there are some virus writers that very well
understand the pschy of the average internet user.
On September 5 and 6 the State Department of the U.S.A. will
held a secret conference (according
an article by Salman Rushdie in the Washington Post)
is being held to find out
why so many people in the world hate the United States. What
strikes me about this conference is that they seems not to
know why. First of all, I would like to remark that they are
also the most loved country in the world. Many people all over
the world dream about immigrating to the United States. And
also would like to say that there are many good and honest
people living in the United States.
I think it is rather obvious why so many people hate the United
States. They are the most powerful and richest country in the
world. But that alone would not be enough reason. They are also
wanting to be the boss over this world. Just recently a law,
nicknamed "The Invasion of The Hague Act", passed
the congres stating that it is okay to have a military campain
against our country in case any American soldier would appear
before the International Court of
Justice, which is seated in The Hague, and was established by the
United Nations. We are a friendly country often supporting the
United States because they help liberating our country from the German
occupation during World War II. Why are they against an international
court? What are they afraid of? That others would judge them? And
why then, can they judge others?
In the past years there have been some other international treaties
that they have cancelled. They are the country consuming the most
energy in the world, yet, they do not feel an urge to reduce their
oil consumption. They are importing about 55% of their oil from
abroad. Almost all their military campains in the past
decades, including the last one against Afganistan,
were also
related to securing their supply of oil. The U.S. government has
been supporting the Saudia Arabic government to secure some of the best
oil contracts they have. They want peace in the middle east, otherwise
the steady flow of cheap oil would dry up, and ruin the economical
success of the United State.
Yet, although they are the richest country in the world, many
people are poor. About 3% of the population is in jail. (That might
be the highest rate in the world.) Most of those in jail are from
the poorer parts of society. They are maybe also the country with
the highest homocide rate in the world (not counting those countries
where there is an ongoing civil war). Yet, the Americans view
themselves as the best country in the world. And because of this
they have a hard time understanding how the rest of the world is
viewing them. I know from first hand experience that the average
Americans has a rather limited knowledge of the rest of the world.
They see themselves as the biggest country in the world, but are
forgetting that they have about 4% of the world population. Yet
they are using about half the world natural resources.
I should comment that the Netherlands is also amonght the rich
Western countries. But their are not many people who hate us.
We are known for our openmindness and our knowledge of the rest
of the world. Most Dutch people speak one foreign language. At
least three foreign languages are being taught in highschool.
It is not without reason that one of our former prime ministers
is now the head of the UNCHR, and that one of our former ministers
is a leading figure during
Johannesburg summit on sustainable development, where also our
crown prince plays an important role in one of the smaller conferences
on water management. Yet, president Bush does not find this summit
worth a visit.
I am afraid that the Western world will be shake on its foundations
when the global oil crisis
will hit us.
Why do they hate us?(cont'd)
This morning, I told my boss about the above mentioned
conference. His reply to why some many people hate the
Americans is because they ask themselves the question:
"Why do they hate us?".
(follow-up)
De Bijenkorf
This week a new establishment of the shop
"De Bijenkort"
(The Beehive) was opened in Enschede. Today,
Annabel and I went to have a
look. At the third floor there was an exhibition of some
Dutch photographer including some nude pictures.
One showed a squinting woman and a woman from the side that
is standing bend forward so far that you can see some
public hair. Another showed an almost naked "punk" girl
with leather boots and a leather collar around her neck
standing on hands and feets on a stool. Although these
images are not very explicit and maybe a little playful,
some people still may experience them as very erotic.
What surprised me most about it, is that a "high-class"
department store is putting such pictures on display.
(follow-up)
Then at McDonalds, the Happy Meal had a small
Ieoor doll in it. I asked Annabel to go and ask
if the might have a Winnie-the-Pooh doll. She
went back, and to my surprise, she came back
with the same type of Winnie-the-Pooh doll that
Andy had thrown out of
the windows on Sunday,
June 9. Annabel also told me that it was the
last one they had. They gave these Winnie-the-Pooh
dolls about a year ago, when there was a related
movie being shown in the theaters. Apparently,
they have been finishing some stock left over
from last year, in lack of any current running
theme. When we came home, we showed it to Li-Xia
and Andy, and we all felt very happy about it.
Home |
July 2002 |
September 2002 |
Random memories