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And then we're going to turn to the question of efficiency. How do we measure efficiency of algorithms? Which is going to be a really important thing that we want to deal with, and we'll start it today, it's undoubtedly going to take us a couple more lectures to finish it off.
然后我们会回头继续讨论效率问题,我们如何计算算法的效率？,我们处理这些问题的时候,最重要的事情是什么？,我们今天要去讨论这个问题，毫无疑问我们要用,挺多节课来学习这个。
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and how that relates to the efficiency of the market.
还有这个与市场效率有什么关系。
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So what this says is the efficiency of any reversible engine T1 has to be one minus T2 over T1.
这就是说,任何可逆热机的效率都是,负T2除以。
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And with respect to securities selection, you want to consider your skills and you want to consider the efficiency of markets when you're making your decisions as to whether or not to pursue passive management or active management.
证券选择方面,要考虑自身能力与市场有效性,从而决定,是采用被动型管理,还是主动型管理
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But the things we were trying to stress were that it's an important design decision when you are coming up with a piece of code, as to what kind of efficiency your code has.
但是我们这里要强调的是,当你写代码的时候,决定你的代码的效率的很重要的事情，就是你的设计决定。
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If the vehicle in the unfortunate circumstances of a collision, has to be able to maintain the security of the hydrogen which means more mass, which means a lot of the efficiency is being squandered What's the environmental impact of hydrogen production?
如果车辆,在碰撞中发生了不幸，要仍然能够保持氢气的安全性的话,意味着需要更多的质量，也就是说大部分效率被浪费了,制氢对环境有什么影响呢？
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People do that with differing levels of efficiency.
人们存储能量的效率各不相同
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In the meantime, I believe that the U.S. is doing quite a bit of work in terms of raising fuel efficiency standards,
同时，我相信美国在提高燃料效率标准方面做了不少事，
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And I just want to write those because what I really want to get at is what's the efficiency of the whole thing?
我写出这些的原因,是我真正想得到的是,它的效率？
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So now let's look at the efficiency of our irreversible engine.
再来看看,不可逆热机的效率。
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And so instead of defining efficiency the way you've got it written there, I'm going to define what's called something different for a refrigerator which is called the coefficient of performance.
现在我们不用,效率的那个定义，我给出一个,有关制冷机的,新的定义,叫做制冷系数。
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As long as it's reversible, you know what the efficiency has to be, and in principle, you could break it down into a bunch of steps that you could formulate as isothermal and adiabatic.
只要这个循环过程是可逆的，你们知道效率是多少，从理论上说，可以将总过程,分解成一系列绝热,和等温的小过程。
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And the second thing that we talked about is this idea that we want you to in fact learn how to relate a choice you make about a piece of code to what the efficiency is going to be.
关于这个方法第二件事,就是我们实际上希望,你在写代码的时候,能做出优化效率的选择,因为此。
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But what we-- what we do want to do, is to give you some intuition about how to approach questions of efficiency.
但是我们想要你们产生，对于处理效率问题的一些直觉,你应该会意识到为什么。
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I mean, you grew up in an age when computers were blazingly fast, and have tons of memory, so why in the world do you care about efficiency?
我的意思是你们是伴随着,计算机快速发展成长的，计算机都有这么大的内存,那还在乎效率干嘛呢？
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We've formulated one particular kind of engine, and seen how we can analyze what it does, come up with relations that seem of value for efficiency and other quantities.
这是一个很典型的热机，我们来分析它是怎么工作的，然后得到效率和其它一些,有用物理量之间的关系。
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And we want to help you learn how to map a problem into a class of algorithms of some efficiency That's our goal.
学会如何将一个问题,映射到一类,提升效率的算法中去,这就是我们的目标。
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It makes you believe, initially, in the feasibility of perfect efficiency.
你们就会明白，它一开始让你相信完美效率的可行性。
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So I can define the efficiency of each one of them.
因此可以定义它的效率。
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And in practical terms, we can define the efficiency as the ratio of the heat in to the work out.
在实际中，我们定义,效率为热与功的比值。
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So what we want to do, is, I guess another way of saying it is, efficiency is really about choice of algorithm.
因此我们想做的就是，换种说法，效率实际上是算法的选择，我们想要培养你们。
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OK. So to do this, we need a little more abstract way of talking about efficiency, and so, the question is, how do we think about efficiency? Typically there's two things we want to measure.
好，为了达到这个目的,我们需要用一种有点，抽象的方式去讨论效率，这衍生出来,一个问题，我们该怎么去认识效率？,主要来说我们有两个要量化的东西。
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If you look at the behavior of groups of active managers and the dispersion of returns, I think it gives you some idea of what the efficiency is with which assets in these individual assets classes are priced.
如果观察一下主动管理型的基金经理们,和他们的投资收益分布,我想它会告诉你一些信息,哪些资产是有效定价
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