シャドーイング練習: P2 什么是机器学习【2024公认最好的 | 吴恩达机器学习 | 教程 | Machine Learning Specialization(超爽中英!)】 - 動画で英語スピーキングを学ぶ

レッスンを作成中...
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So what is machine learning?
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In this video you learn a definition of what it is
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and also get a sense of when you might want to apply it.
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Let's take a look together.
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Here's the definition of what is machine learning that is attributed to Arthur Samuel.
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He defined machine learning as the field of study that gives computers the ability to learn without being explicitly programmed.
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Salva's claim to fame was that back in the 1950s he wrote a checkers playing program.
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And the amazing thing about this program was that Arthur Samuel himself wasn't a very good checkers player.
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What he did was he had programmed a computer to play maybe tens of thousands of games against himself.
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And by watching what sorts of board positions tended to lead to wins and what positions tended to lead to losses,
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the checkers playing program learned over time what are good or bad board positions.
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By trying to get to good and avoid bad positions, his program learned to get better and better at playing checkers.
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Because the computer had the patience to play tens of thousands of games against itself,
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it was able to get so much checkers playing experience that eventually it became a better checkers player than author Samuel himself.
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Now, throughout these videos, besides me trying to talk about stuff,
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I'll occasionally ask you a question to help make sure you understand the content here's one about what happens
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if the computer had played far fewer games please take a look
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and pick whichever you think is a better answer thanks for looking at the quiz and so
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if you had selected this answer would have made it worse
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then you got it right in general the more opportunities you give a learning algorithm to learn, the better it will perform.
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If you didn't select the correct answer the first time, that's totally okay too.
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The point of these quiz questions isn't to see if you can get them all correct on the first try.
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These questions are here just to help you practice the concepts you're learning.
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Author Samuel's definition was a rather informal one, but in the next two videos, we'll dive deeper together into what are the major types types of machine learning algorithms.
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In this class, you learn about many different learning algorithms.
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The two main types of machine learning are supervised learning and unsupervised learning.
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We'll define what these terms mean more in the next couple videos.
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Of these two, supervised learning is the type of machine learning that is used most in many real -world applications,
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and that has seen the most rapid advancement and innovation.
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In this specialization, which has three causes in total, the first and second causes will focus on supervised learning,
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and the third will focus on unsupervised learning.
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You might have also heard of reinforcement learning.
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This is another type of machine learning algorithm that I'll talk about briefly,
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but by far the two most used types of learning algorithms today are supervised learning and unsupervised learning.
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That's why we'll spend most of this class talking about them.
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The other thing we're going to spend a lot of time on in this specialization is practical advice for applying learning algorithms.
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This is something I feel pretty strongly about.
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Teaching about learning algorithms is like giving someone a set of tools
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and equally important
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or even more importance than making sure you have great tools is making sure you know how to apply them
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because you know what good is it
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if someone were to give you a state -of -the -art hammer
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or a state -of -the -art hand drill
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and say good luck now you have all the tools you
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need to build a three -story house It doesn't really work like that.
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And so too in machine learning, making sure you have the tools is really important.
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And so it's making sure that you know how to apply the tools of machine learning effectively.
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So that's what you get in this class, the tools as well as the skills in applying them effectively.
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I regularly visit with friends and teams in some of the top tech companies.
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And even today, I see experienced machine learning teams apply machine learning algorithms to some problems.
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And sometimes they've been going at it for six months without much success.
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And when I look at what they're doing, I sometimes feel like I could have told them six months ago that the current approach won't work.
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And there's a different way of using these tools that will give them a much better chance of success.
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So in this class, one of the relatively unique things you learn is you learn
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a lot about the best practices for how to actually develop a practical, valuable machine learning system.
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This way, you're less likely to end up in one of those teams
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that end up losing six months going in the wrong direction.
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In this class, you gain a sense of how the most skilled machine learning engineers build systems,
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and I hope you finish this class as one of those very rare people in today's world
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that know how to design and build serious machine learning systems.
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So that's machine learning.
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In the next video, let's look more deeply at what is supervised learning and also what is unsupervised learning.
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In addition, you learn when you might want to use each of them, supervised and unsupervised learning.
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I'll see you in the next video.

このレッスンの語彙とスピーキングのポイント

この動画には、シャドーイング用の文が64文、単語が927語あります。 音声の長さは5:36です。 話す速さは1分あたり約166語で、日常会話に近い自然なペースです。 単語の88%は英語の頻出3,000語に含まれます。残りは練習の前に確認しておきましょう。

この動画の重要語彙

動画に出てくる覚えておきたい単語15語を、発音と意味つきで紹介します。

単語発音意味
algorithm 名詞/ˈælɡəɹɪðm̩/アルゴリズム, 演算手順
practical 形容詞/ˈpɹæk.tɪ.kəl/実践的な
select 動詞/sɪˈlɛkt/選ぶ
skill 名詞/skɪl/腕, 技
quiz 名詞/kwɪz/クイズ
deeply 副詞/ˈdi(ː)pli/深く
equally 副詞/ˈiːkwəli/等しく, 平等に
occasionally 副詞/əˈkeɪʒənəli/たまに, 偶に
rapid 形容詞/ˈɹæp.ɪd/速い, 急な
fame 名詞/feɪm/有名
innovation 名詞/ˌɪn.əˈveɪ.ʃən/イノベーション, 革新
patience 名詞/ˈpeɪ̯.ʃəns/辛抱, 忍耐
hammer 名詞/ˈhæmɚ/金槌, 槌
dive 動詞/daɪv/潜る
drill 名詞/dɹɪl/ドリル

注意したい発音

話し手はI'll, we'll, you'reなど、短縮形や弱形を16回使っています。聞こえたとおりの短い形で発音しましょう。

  • 「sh」と「zh」の音: occasionally /əˈkeɪʒənəli/, innovation /ˌɪn.əˈveɪ.ʃən/, patience /ˈpeɪ̯.ʃəns/, specialization [ˌspɛʃəlaɪ̯ˈzeɪ̯ʃn̩]
  • 長い単語(アクセントの位置に注意): occasionally /əˈkeɪʒənəli/, innovation /ˌɪn.əˈveɪ.ʃən/, specialization [ˌspɛʃəlaɪ̯ˈzeɪ̯ʃn̩], reinforcement /ˌɹiːɪnˈfɔːsmənt/

この動画での練習方法

  1. まず声を出さずに動画を最後まで聞き、知らない単語をメモします。
  2. まず0.75倍速で一文ずつシャドーイングし、慣れてきたら通常の速度に戻します。
  3. 自分の声を録音して元の音声と比べます。algorithm, practical, selectなどの単語に特に注意しましょう。

シャドーイングとは?英語上達に効果的な理由

シャドーイング(Shadowing)は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的:ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影(shadow)」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。

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