搜狗做题网哪位高手帮我想一篇after dinner speech
来源：学生作业帮 编辑：搜狗做题网作业帮 分类：英语作业 时间：2024/05/16 16:35:10
哪位高手帮我想一篇after dinner speech
就是餐后演讲,话题需要轻松一点,说4分钟,当然需要英文的,
就是餐后演讲,话题需要轻松一点,说4分钟,当然需要英文的,
Good evening Ladies and Gentlemen.
There comes a time when people at a technical conference like this need something more relaxing. A change of pace. A shift of style. To put aside all that work stuff and think of something refreshingly different.
So let's talk about coding theory. There are perhaps some of you here tonight who are not experts in coding theory, but rather have been dragged here kicking and screaming. So I thought it would be a good idea if I gave you a sort of instant, five minute graduate course in coding theory.
Coding theorists are concerned with two things. Firstly and most importantly they are concerned with the private lives of two people called Alice and Bob. In theory papers, whenever a coding theorist wants to describe a transaction between two parties he doesn't call then A and B. No. For some longstanding traditional reason he calls them Alice and Bob.
Now there are hundreds of papers written about Alice and Bob. Over the years Alice and Bob have tried to defraud insurance companies, they've played poker for high stakes by mail, and they've exchanged secret messages over tapped telephones.
If we put together all the little details from here and there, snippets from lots of papers, we get a fascinating picture of their lives. This may be the first time a definitive biography of Alice and Bob has been given.
In papers written by American authors Bob is frequently selling stock to speculators. From the number of stock market deals Bob is involved in we infer that he is probably a stockbroker. However from his concern about eavesdropping he is probably active in some subversive enterprise as well. And from the number of times Alice tries to buy stock from him we infer she is probably a speculator. Alice is also concerned that her financial dealings with Bob are not brought to the attention of her husband. So Bob is a subversive stockbroker and Alice is a two-timing speculator.
But Alice has a number of serious problems. She and Bob only get to talk by telephone or by electronic mail. In the country where they live the telephone service is very expensive. And Alice and Bob are cheapskates. So the first thing Alice must do is MINIMIZE THE COST OF THE PHONE CALL.
The telephone is also very noisy. Often the interference is so bad that Alice and Bob can hardly hear each other. On top of that Alice and Bob have very powerful enemies. One of their enemies is the Tax Authority. Another is the Secret Police. This is a pity, since their favorite topics of discussion are tax frauds and overthrowing the government.
These enemies have almost unlimited resources. They always listen in to telephone conversations between Alice and Bob. And these enemies are very sneaky. One of their favorite tricks is to telephone Alice and pretend to be Bob.
Well, you think, so all Alice has to do is listen very carefully to be sure she recognizes Bob's voice. But no. You see Alice has never met Bob. She has no idea what his voice sounds like.
So you see Alice has a whole bunch of problems to face. Oh yes, and there is one more thing I forgot so say - Alice doesn't trust Bob. We don't know why she doesn't trust him, but at some time in the past there has been an incident.
Now most people in Alice's position would give up. Not Alice. She has courage which can only be described as awesome. Against all odds, over a noisy telephone line, tapped by the tax authorities and the secret police, Alice will happily attempt, with someone she doesn't trust, whom she cannot hear clearly, and who is probably someone else, to fiddle her tax returns and to organize a coup d'etat, while at the same time minimizing the cost of the phone call.
A coding theorist is someone who doesn't think Alice is crazy.
Information
The other thing coding theorists are concerned with is information. Nothing else is like information. Information is very peculiar stuff. It can both be created and destroyed. You can steal it without removing it. You can often get some just by guessing. Yet it can have great value. It can be bought and sold.
One type of information is called Money.
There are people who refuse to concede that money can be created and destroyed. They spend their entire lives altering records and making adjustments to ensure that every time a bit of money leaves some place, an equal bit seems to appear somewhere else. These people are called accountants.
Source, channel and secrecy coding
Coding theory, like Gaul, is divided into three parts, called source coding, channel coding and secrecy coding.
Source coding
First I'll tell you about source coding. Source coding is what Alice uses to save money on her telephone bills. It is usually used for data compression, in other words, to make messages shorter.
There is a story about a student of information theory on his first day at college. He had entered a strange, bizarre world. The only sounds were the occasional calling out of a number by one of the professors, followed by laughter. One professor would say '52', there would be a short pause then peals of laughter. Someone else says '713', same thing, everyone falls down laughing.
"What's going on here?" he asked his tutor.
"We're telling jokes," said his tutor.
"Telling jokes?"
"Yes, you see, we've all worked here so long we know each other's jokes. There are a thousand of them. So, being information theorists we applied data compression. We just assigned them all numbers, 0 through 999. It saves a lot of time and effort. Would you like to try? Just say any number 0 to 999..."
He wasn't fully convinced. But he tried. Very quietly he whispered "477".
Hardly a murmur.
He looked at his tutor. "What's wrong?" he said. "Try again," says the tutor.
So he does. "318" - same again, not a thing, hardly a murmur.
"Something's wrong," he says.
"Well," says the tutor, "it's like this - it's not so much the joke as the way you tell it!"
There is a curious sequel to this story. This student eventually succeeded by accident in the most dramatic and unexpected way. He called out a number outside the range 0 to 999. "Minus 105," he said.
At first there was stunned amazement, then first one professor laughed, then another then another, till they were all rolling about holding their sides.
None of them had heard that one before.
Channel coding
Next we come to channel coding. Channel coding is what Alice uses to overcome the noise and interference on the line. Most people have a natural instinct for channel coding. What they do is to spell out important words. This adds redundancy and enables the listener to cross check. If part of the message is lost the missing bit can be reconstructed from the remaining part.
Many organizations such as the military, the aviation community, the Police and so on use a standard phonetic alphabet specially designed for this purpose. It goes Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, etc. So one says "Mike" and "November", which is much clearer than saying "M" and "N" which are easily confused otherwise.
Alice uses this to explain to Bob that her husband Michael is getting suspicious of her stock option dealing.
"I have to tell you about Mike," she says. But Bob hears "I XXve to tell u XXt Xxike".
"What's that again?" says Bob. "I have to tell you about Mike," says Alice.
"Didn't get the last word Alice," says Bob, "can you spell it out?"
"Mike India Kilo Echo" says Alice.
"Got India Kilo Echo, what was the first word?" says Bob.
"Mike"
"Can you spell that?"
"Mike India Kilo Echo" etc.
Actually there have been lots of other phonetic alphabets. The predecessor to the International Phonetic Alphabet went Able, Baker, Charlie...
Then there are those based on names of countries:- Africa, Brazil, Chile, Denmark, England, France, Greenland, Holland, India, Japan, Khazakistan, Lithuania, Morocco, Niger, Oman, Papua, Qatar, Russia, Spain, Tanzania, Uruguay, Venezuela, Westphalia, Yemen, Xanadu, Zambia.
My personal favorite is this:
A for 'Orses
B for Mutton
C for Yourself
D for Mation
E for Brick
F for Vescence
G for Police
H for Consent
I for Lutin
J for Orange
K for Teria
L for Leather
M for Sis
N for Mation
O for A Muse of Fire
P for Ate
Q for A Song
S for Something Else
T for Two
U for Mism
V for La France
W for Mism
X for Breakfast
Y for Lover
Z (zee) for yourself
后面还有,地址http://downlode.org/Etext/alicebob.html
你自己复制有用信息过去吧.
这篇可以参考
There comes a time when people at a technical conference like this need something more relaxing. A change of pace. A shift of style. To put aside all that work stuff and think of something refreshingly different.
So let's talk about coding theory. There are perhaps some of you here tonight who are not experts in coding theory, but rather have been dragged here kicking and screaming. So I thought it would be a good idea if I gave you a sort of instant, five minute graduate course in coding theory.
Coding theorists are concerned with two things. Firstly and most importantly they are concerned with the private lives of two people called Alice and Bob. In theory papers, whenever a coding theorist wants to describe a transaction between two parties he doesn't call then A and B. No. For some longstanding traditional reason he calls them Alice and Bob.
Now there are hundreds of papers written about Alice and Bob. Over the years Alice and Bob have tried to defraud insurance companies, they've played poker for high stakes by mail, and they've exchanged secret messages over tapped telephones.
If we put together all the little details from here and there, snippets from lots of papers, we get a fascinating picture of their lives. This may be the first time a definitive biography of Alice and Bob has been given.
In papers written by American authors Bob is frequently selling stock to speculators. From the number of stock market deals Bob is involved in we infer that he is probably a stockbroker. However from his concern about eavesdropping he is probably active in some subversive enterprise as well. And from the number of times Alice tries to buy stock from him we infer she is probably a speculator. Alice is also concerned that her financial dealings with Bob are not brought to the attention of her husband. So Bob is a subversive stockbroker and Alice is a two-timing speculator.
But Alice has a number of serious problems. She and Bob only get to talk by telephone or by electronic mail. In the country where they live the telephone service is very expensive. And Alice and Bob are cheapskates. So the first thing Alice must do is MINIMIZE THE COST OF THE PHONE CALL.
The telephone is also very noisy. Often the interference is so bad that Alice and Bob can hardly hear each other. On top of that Alice and Bob have very powerful enemies. One of their enemies is the Tax Authority. Another is the Secret Police. This is a pity, since their favorite topics of discussion are tax frauds and overthrowing the government.
These enemies have almost unlimited resources. They always listen in to telephone conversations between Alice and Bob. And these enemies are very sneaky. One of their favorite tricks is to telephone Alice and pretend to be Bob.
Well, you think, so all Alice has to do is listen very carefully to be sure she recognizes Bob's voice. But no. You see Alice has never met Bob. She has no idea what his voice sounds like.
So you see Alice has a whole bunch of problems to face. Oh yes, and there is one more thing I forgot so say - Alice doesn't trust Bob. We don't know why she doesn't trust him, but at some time in the past there has been an incident.
Now most people in Alice's position would give up. Not Alice. She has courage which can only be described as awesome. Against all odds, over a noisy telephone line, tapped by the tax authorities and the secret police, Alice will happily attempt, with someone she doesn't trust, whom she cannot hear clearly, and who is probably someone else, to fiddle her tax returns and to organize a coup d'etat, while at the same time minimizing the cost of the phone call.
A coding theorist is someone who doesn't think Alice is crazy.
Information
The other thing coding theorists are concerned with is information. Nothing else is like information. Information is very peculiar stuff. It can both be created and destroyed. You can steal it without removing it. You can often get some just by guessing. Yet it can have great value. It can be bought and sold.
One type of information is called Money.
There are people who refuse to concede that money can be created and destroyed. They spend their entire lives altering records and making adjustments to ensure that every time a bit of money leaves some place, an equal bit seems to appear somewhere else. These people are called accountants.
Source, channel and secrecy coding
Coding theory, like Gaul, is divided into three parts, called source coding, channel coding and secrecy coding.
Source coding
First I'll tell you about source coding. Source coding is what Alice uses to save money on her telephone bills. It is usually used for data compression, in other words, to make messages shorter.
There is a story about a student of information theory on his first day at college. He had entered a strange, bizarre world. The only sounds were the occasional calling out of a number by one of the professors, followed by laughter. One professor would say '52', there would be a short pause then peals of laughter. Someone else says '713', same thing, everyone falls down laughing.
"What's going on here?" he asked his tutor.
"We're telling jokes," said his tutor.
"Telling jokes?"
"Yes, you see, we've all worked here so long we know each other's jokes. There are a thousand of them. So, being information theorists we applied data compression. We just assigned them all numbers, 0 through 999. It saves a lot of time and effort. Would you like to try? Just say any number 0 to 999..."
He wasn't fully convinced. But he tried. Very quietly he whispered "477".
Hardly a murmur.
He looked at his tutor. "What's wrong?" he said. "Try again," says the tutor.
So he does. "318" - same again, not a thing, hardly a murmur.
"Something's wrong," he says.
"Well," says the tutor, "it's like this - it's not so much the joke as the way you tell it!"
There is a curious sequel to this story. This student eventually succeeded by accident in the most dramatic and unexpected way. He called out a number outside the range 0 to 999. "Minus 105," he said.
At first there was stunned amazement, then first one professor laughed, then another then another, till they were all rolling about holding their sides.
None of them had heard that one before.
Channel coding
Next we come to channel coding. Channel coding is what Alice uses to overcome the noise and interference on the line. Most people have a natural instinct for channel coding. What they do is to spell out important words. This adds redundancy and enables the listener to cross check. If part of the message is lost the missing bit can be reconstructed from the remaining part.
Many organizations such as the military, the aviation community, the Police and so on use a standard phonetic alphabet specially designed for this purpose. It goes Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, etc. So one says "Mike" and "November", which is much clearer than saying "M" and "N" which are easily confused otherwise.
Alice uses this to explain to Bob that her husband Michael is getting suspicious of her stock option dealing.
"I have to tell you about Mike," she says. But Bob hears "I XXve to tell u XXt Xxike".
"What's that again?" says Bob. "I have to tell you about Mike," says Alice.
"Didn't get the last word Alice," says Bob, "can you spell it out?"
"Mike India Kilo Echo" says Alice.
"Got India Kilo Echo, what was the first word?" says Bob.
"Mike"
"Can you spell that?"
"Mike India Kilo Echo" etc.
Actually there have been lots of other phonetic alphabets. The predecessor to the International Phonetic Alphabet went Able, Baker, Charlie...
Then there are those based on names of countries:- Africa, Brazil, Chile, Denmark, England, France, Greenland, Holland, India, Japan, Khazakistan, Lithuania, Morocco, Niger, Oman, Papua, Qatar, Russia, Spain, Tanzania, Uruguay, Venezuela, Westphalia, Yemen, Xanadu, Zambia.
My personal favorite is this:
A for 'Orses
B for Mutton
C for Yourself
D for Mation
E for Brick
F for Vescence
G for Police
H for Consent
I for Lutin
J for Orange
K for Teria
L for Leather
M for Sis
N for Mation
O for A Muse of Fire
P for Ate
Q for A Song
S for Something Else
T for Two
U for Mism
V for La France
W for Mism
X for Breakfast
Y for Lover
Z (zee) for yourself
后面还有,地址http://downlode.org/Etext/alicebob.html
你自己复制有用信息过去吧.
这篇可以参考