Wednesday, December 06, 2006

Does the GOD exist?

I have several times discussion about the existence of the God with several of my friends.
This time, I'll try to answer one of statements that intends to refuse the existence of the God.
I call IT as the God, and it doesn't limit from a belief that believes with multiple Gods/gods.

One day, there is a man, called Bob, that wants his hair and beard are trimmed such that it looks better.
Therefore, he goes to a barbershop.
During the barber, called Charlie, does his task, they involve in a discussion about many things and one of them is about the existence of the God.

Bob says, "I don't believe if the God exist"
Charlie says, "How come? don't you see many of his creations?"
Bob says, "Mmm, but as you see.... if the God is merciful and beneficent then how come so many people are in hunger and stay in poverty and sick".
Charlie says,"So ?"
Bob says, "So there is no such thing that we call God. Even there is so He is not as nice as we think because He lets it happens".
Charlie is silent and try not to oppose the Bob's opinion.

After everything finished, Charlie pays the fee and leaves the barbershop.
While he is standing in front of the barbershop, he sees a beggar with awful hair and bread.
Suddenly, Charlie shouts, "I do believe that there is no barber in this world".
Surely, Bob feels offended about that statements.
Bob responses, "I'm a barber and I exist, so you're totally wrong".
Charlie says, "If he exists why there is people with awful hair and bread? even he stays exactly in front of a barbershop."
Without any further comments, Charlie goes continuing his day.

Lesson learnt, Barber exists but a beggar doesn't come to him to trim his hair, and if there is a beggar.
In the case of God, THIS THING exists and we just need to come and ask HIM for help.
are we so arrogant such that we still demand that the God helps us even we don't tell him what we want?

before I thought that
if the GOD exists then there is no poverty
and I think this premise is too strong
so I refine it: if the God exists and we ask HIM for help then there is no poverty dfd
Further question:
how about if we have already asked HIM a help ?
[thinking in progress]

Tuesday, December 05, 2006


What does it mean Resilience system?
does it enough by measuring.... using availability?????

Need an answer??? :(

Availability and Reliability

Those words.. in common passwords in secure and dependable system (i.e., critical system).

In Avizenis et al. [TSDC,2004]
- Availability : the readiness of the system to provide a correct service
- Reliability : the continuity of the system to provide a correct service

based on these definitions, it seems both properties are going in the same polarity. [Hypothesis] For instance, if a system is highly available then it means the system is also reliable.

However, I don't believe about that because if there is an attribute/a property is a subset of another than we shouldn't measure the system with both properties.
At least it is belief in Decision Science community.

In software engineering, we always have them (i.e., reliability and availability) as non-functional requirements, and we can assess how good the system using how is the achievements of the system towards its NFRs.
So if the hypotheses are correct than we should drop one of them (either reliability or availability)


They explain how both property are related but the are not going in the same polarity or direction.
They have intersection between them but not sub-set (as my hypothesis).
Moreover, in [1] it states that reliability is the part in calculating availability.
Availability is refined as the probability that a system is not failed or undergoing in maintenance when it needs to be used.
Reliability just represents the probability of a system will operate when it needs to be used.

Reliability doesn't take into account the fact that a system can have a failure/downtime.
It only measures the number of failure within certain period, or probability of having failure within a certain period of time.

Availability takes into consideration how much time that is necessary to make the system back into operate mode anymore.
Availability = Uptime / (Uptime + Downtime)

MTTF stands for Mean-Time-To-Failure, it means how much is the average of time between failures
MTTR stands for Mean-Time-To-Repair, means how much is the average of time to repair the system for a failure

But we can simply remove reliability and it can be represented in availability because
Availability of a system can be decreased even when the reliability of the system is constant. It is because the MTTR is increased or the other way around.

So.. I hope you all understand what is the difference between two properties

In IEEE Transaction in Secure and Dependable Computing, [Avizenis, 2004] defines that dependability of a system are characterized as: availability, reliability, integrity, and maintainability.

so my next question.. I think we can derive availability from reliability + maintainability
;-) ... still think

But the next question