starting up a new project --- a title a day.
just for any words, explain, give a lesson. completely from myself only. hope can last for 1 year.
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Projection
projection is..... projection. in physic, a projection of A on B is an image of A on B -- A'. just like a sun shining on an object (A), that will give a shadow (A') on behind. e.g. a point project on a line, a point project on a plane, a cylinder. for human, we can only imagine a 3-D object project on a 2-D object.
the most easiest projection is the dot product between 2 vectors.
in mathematics, a projection can be presented as a transformation, or matrix (in linear case)
a point can be represented as a vector. the projection for a point on x-y plane is simply taken the first 2 component. on x-z plane is taken the 1st and 3rd component. we can write the transformation matrix as 2X3 :
1 0 0
0 1 0 for x-y plane projection.
from this, we know that for a general plane projection, we can write a matrix to represent it.
the way i do is first transform the space such that the general plane to be x'-y' plane.
to do so, we need to know 2 new matrix. translation and rotation. but this is far away from today topic.
to extend this idea. although we can not imagine higher-D projection, but we can calculate it.
for example. the matrix :
1 0 0 0
0 1 0 0
0 0 1 0
is a projection matrix from 4-D to 3-D. so, in every point of 3-D space, like the points on a pencil, we can thing that the "real" pencil is a 4-D object, but now, be projected on a 3-D space. the funny thing is, by using an inverse transform, we can construct the 4-D space!
D = T P // D is the 3-D vector representing a pencil, T is the 4-D -> 3-D transform, P is the 4-D vector of the pencil.
by solving above equation, we can know how the 4-D pencil look like!~ HA~
however, the inverse transform of T does not exist. that led to multiple solution for P. which mean, for 1 point in 3-D space, there are multiple points in 4-D space can be projected onto it. imagine a cube project on a sheet of paper. the shadow on the the paper is not formed by single point of the cube.
there are many other application for projection matrix. like computer game, they need to project a "3-D" world on a screen. in optics experiment, projection matrix is wildly used, to calculate how a light beam will project on. in civil engineering, they need to calculate how side wind move the building.
the concept of projection is even used out of it original meaning in other field, like business. projected profit -- which mean the expected profit. this kind of projection is mean the projection on time, not on space.
Wednesday, May 28, 2008
Friday, May 16, 2008
a suggestion for youtube
can you tube display all links that will link to the same clips? so that everyone can see other comments, not even in the comment column, but also from other blogers.
and, anyone who want to post the clip in their blog, can easily, check is others already do so. so, skip alot redundancy. keep the web space more organized.
and, anyone who want to post the clip in their blog, can easily, check is others already do so. so, skip alot redundancy. keep the web space more organized.
Wednesday, May 14, 2008
Charity no more
Every time, some disasters happened, people will automatically turn to Charities. Most think it is the only and fastest way to save those people.
For the reasons that go for Charities, donate money. As I know, is just not enough. Most will say it is natural for an educated or humane mankind should act and think. There is no question for donating money, blood or any kind of help. Just like watching a kid sinking on a pool, there is no way to not save the kid. This is our Instinct.
Just hold on a bit. How about the kid is not the first time sinking on the pool? The kid is means to do so? Shall we still save his life? This is same as: will you give money when some disable asked for? Do you have the responsibilities to take care for their disable? It depends, right?
Yes, there are many disasters that come so suddenly, unpredictable and fatally. If it happened in well developed countries with well social mechanism, the Giant social machinery started automatically, and keeping people from tragedies. I guess the disaster will very soon recover. Think about United State. Just like a healthy body will quickly recover from illness. On the opposite, if the country has poor system, with a lot man-made problems. When disaster come, and quickly become an incidence that due to terrible social system. Shall we help?
The human body analogy is very good to illustrate the idea. A baby, when get attack from virus, we should help, since it cannot resist the virus naturally. For an adult, got sick is due to lack of exercise, having good hobbies like drug, over sex. Should we help him? His illness/disable is totally due to himself! (Ok, you can say, partly by the virus, which does not make any healthy body die) there is no way to take the responsibilities. Otherwise, he will take over our effort (to keep ourselves healthy, keep ourselves away from bad habits) for free.
Now a day, China and Burma, they are not kid countries any more; the country can live better if the stupid government is gone. So, I suggest, not helping them.
OK, not everything should be done due to responsibilities. We should be humanity; helping somebody suffering is no executed. I do not agree. How about the consequence? Have somebody even think about that? If you help the bad country, you are helping those suffering, but also the bad government! Most donated money will not go to the people hands, but the governors. And due to this, the people are keeping suffering.
By keeping hand out of the Charities, it doesn't mean that I am cold blood. If you want something really change and this kind of suffering does not happen again and again. It is the only hard and painful way out. China government spends million and million a year on military and salary for stupid governors. And now even fire people into space! How come it cannot take money out to help her people??? So, by donating money, it is not the way to save the people. The system will just keep the same old day!
By donating money, it is just like a present to China, and we are teaching those people that: Nature Disaster is not a Tragedy at all, is a golden chance to earn money!! I don't need to build a house more resist to earth quark, to flood. Since every time the house fall, I can build a new house for free!! Oh, my death child or relative, oh, next year, when I have a new house, I can make more! All in all, I just need to cry in front of the press!
First time is accident, Second times is forgotten, third times is Incidence, and is mean to do so! The 1976, Tong Shan earth quark, people have study a lot. There should be some prevention for the next event. However, the Chinese suck governors do their best press-cover job. And when I watching the TV, all I see am only Wen Jia bao busy, the surrounding governors still like a wood-log, and seem claim, no big deal.
At last, I really want to know, is the amount of money donated equal the spent?
***
by the way, HK people only know donate money, but not really get involved. Just like many fathers, who only knew give money for their family, but not take care, love them. What is the fucking attitude toward "love" and "care"? Some fools even pray for them, what the hell in their mind?
More over, there are many disasters in the world, why HK people only help Chinese event? I think it is so called Patriotic! It sucks! There is a thing called war, is mainly due to the romantic Patriotism. Japanese, Burma-nese, Thai, European, American are all not "our". If they bite us, we should fuck back, since they are alien. Poor the "Mankind" is.
For the reasons that go for Charities, donate money. As I know, is just not enough. Most will say it is natural for an educated or humane mankind should act and think. There is no question for donating money, blood or any kind of help. Just like watching a kid sinking on a pool, there is no way to not save the kid. This is our Instinct.
Just hold on a bit. How about the kid is not the first time sinking on the pool? The kid is means to do so? Shall we still save his life? This is same as: will you give money when some disable asked for? Do you have the responsibilities to take care for their disable? It depends, right?
Yes, there are many disasters that come so suddenly, unpredictable and fatally. If it happened in well developed countries with well social mechanism, the Giant social machinery started automatically, and keeping people from tragedies. I guess the disaster will very soon recover. Think about United State. Just like a healthy body will quickly recover from illness. On the opposite, if the country has poor system, with a lot man-made problems. When disaster come, and quickly become an incidence that due to terrible social system. Shall we help?
The human body analogy is very good to illustrate the idea. A baby, when get attack from virus, we should help, since it cannot resist the virus naturally. For an adult, got sick is due to lack of exercise, having good hobbies like drug, over sex. Should we help him? His illness/disable is totally due to himself! (Ok, you can say, partly by the virus, which does not make any healthy body die) there is no way to take the responsibilities. Otherwise, he will take over our effort (to keep ourselves healthy, keep ourselves away from bad habits) for free.
Now a day, China and Burma, they are not kid countries any more; the country can live better if the stupid government is gone. So, I suggest, not helping them.
OK, not everything should be done due to responsibilities. We should be humanity; helping somebody suffering is no executed. I do not agree. How about the consequence? Have somebody even think about that? If you help the bad country, you are helping those suffering, but also the bad government! Most donated money will not go to the people hands, but the governors. And due to this, the people are keeping suffering.
By keeping hand out of the Charities, it doesn't mean that I am cold blood. If you want something really change and this kind of suffering does not happen again and again. It is the only hard and painful way out. China government spends million and million a year on military and salary for stupid governors. And now even fire people into space! How come it cannot take money out to help her people??? So, by donating money, it is not the way to save the people. The system will just keep the same old day!
By donating money, it is just like a present to China, and we are teaching those people that: Nature Disaster is not a Tragedy at all, is a golden chance to earn money!! I don't need to build a house more resist to earth quark, to flood. Since every time the house fall, I can build a new house for free!! Oh, my death child or relative, oh, next year, when I have a new house, I can make more! All in all, I just need to cry in front of the press!
First time is accident, Second times is forgotten, third times is Incidence, and is mean to do so! The 1976, Tong Shan earth quark, people have study a lot. There should be some prevention for the next event. However, the Chinese suck governors do their best press-cover job. And when I watching the TV, all I see am only Wen Jia bao busy, the surrounding governors still like a wood-log, and seem claim, no big deal.
At last, I really want to know, is the amount of money donated equal the spent?
***
by the way, HK people only know donate money, but not really get involved. Just like many fathers, who only knew give money for their family, but not take care, love them. What is the fucking attitude toward "love" and "care"? Some fools even pray for them, what the hell in their mind?
More over, there are many disasters in the world, why HK people only help Chinese event? I think it is so called Patriotic! It sucks! There is a thing called war, is mainly due to the romantic Patriotism. Japanese, Burma-nese, Thai, European, American are all not "our". If they bite us, we should fuck back, since they are alien. Poor the "Mankind" is.
no one will farm infertile field , unless someone started
there are some theories:
1, no one will farm infertile field; unless somebody started. (瘦田冇人耕, 耕開有人爭)
2, beautiful girl (boy) is attractive, but people usually don't head for her (him). since people may think, such a beauty must have the other one already.
these common "wisdom" has some relation.
some rare thing (may be beauty, good, or may be ugly, bad), if someone start it, the original mind-set will be broken, and people will all go for it. (2) show the reason. and (1) presenting the action.
so, by playing the trick, one can avoid (using) this as a way to reduce the number of competitors (increase attraction). the secret is keeping people mind-set.
1, no one will farm infertile field; unless somebody started. (瘦田冇人耕, 耕開有人爭)
2, beautiful girl (boy) is attractive, but people usually don't head for her (him). since people may think, such a beauty must have the other one already.
these common "wisdom" has some relation.
some rare thing (may be beauty, good, or may be ugly, bad), if someone start it, the original mind-set will be broken, and people will all go for it. (2) show the reason. and (1) presenting the action.
so, by playing the trick, one can avoid (using) this as a way to reduce the number of competitors (increase attraction). the secret is keeping people mind-set.
Saturday, May 10, 2008
Opensource is the King!
there are alot open source material in web, like wiki, Linux, FireFox, etc
the tread of open source, or a more general idea of sharing stuff should be and needed to be the future.
Although the disadvantage to publisher is alot, the benefit to human society is huge. this give a dramatic force to push us forward. (some said, it is hard. because we are pushed not self-motivate. well it depends. and some said, it will enlarge the wealth gap. yes, of course! and why not?)
one example is Public exam papers: it is forbidden to publish on web now. however, what i see is, if publishment is allowed, exam authority need to give out harder and harder questions, or not repeat or similar type! this really improving student standard!
*****************************
the wealth gap is somehow inevitable. due to Human un-natural society, low- quality human was continuously be produced generation by generation. at some critical point, revolutions out break, the result is low-Q people throw out, let high-Q people stand. look back the Chinese history, in some sense, revolutions started due to social pressure, many be too many people, wealth unbalance, social state not balance (some high-Q people can not have good life. but dummy can live in palace.) if there is no such a gap, then human cannot do some improvement. therefore, in order to avoid, smaller the gap, think about how to live and stand out after the balance.
the tread of open source, or a more general idea of sharing stuff should be and needed to be the future.
Although the disadvantage to publisher is alot, the benefit to human society is huge. this give a dramatic force to push us forward. (some said, it is hard. because we are pushed not self-motivate. well it depends. and some said, it will enlarge the wealth gap. yes, of course! and why not?)
one example is Public exam papers: it is forbidden to publish on web now. however, what i see is, if publishment is allowed, exam authority need to give out harder and harder questions, or not repeat or similar type! this really improving student standard!
*****************************
the wealth gap is somehow inevitable. due to Human un-natural society, low- quality human was continuously be produced generation by generation. at some critical point, revolutions out break, the result is low-Q people throw out, let high-Q people stand. look back the Chinese history, in some sense, revolutions started due to social pressure, many be too many people, wealth unbalance, social state not balance (some high-Q people can not have good life. but dummy can live in palace.) if there is no such a gap, then human cannot do some improvement. therefore, in order to avoid, smaller the gap, think about how to live and stand out after the balance.
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