This presentation Neural Network will help you understand what is a neural network, how a neural network works, what can the neural network do, types of neural network and a use case implementation on how to classify between photos of dogs and cats. Deep Learning uses advanced computing power and special types of neural networks and applies them to large amounts of data to learn, understand, and identify complicated patterns. Automatic language translation and medical diagnoses are examples of deep learning. Most deep learning methods involve artificial neural networks, modeling how our brains work. Neural networks are built on Machine Learning algorithms to create an advanced computation model that works much like the human brain. This neural network tutorial is designed for beginners to provide them the basics of deep learning. Now, let us deep dive into these slides to understand how a neural network actually work.
Below topics are explained in this neural network presentation:
1. What is Neural Network?
2. What can Neural Network do?
3. How does Neural Network work?
4. Types of Neural Network
5. Use case - To classify between the photos of dogs and cats
Simplilearn’s Deep Learning course will transform you into an expert in deep learning techniques using TensorFlow, the open-source software library designed to conduct machine learning & deep neural network research. With our deep learning course, you'll master deep learning and TensorFlow concepts, learn to implement algorithms, build artificial neural networks and traverse layers of data abstraction to understand the power of data and prepare you for your new role as deep learning scientist.
Why Deep Learning?
It is one of the most popular software platforms used for deep learning and contains powerful tools to help you build and implement artificial neural networks.
Advancements in deep learning are being seen in smartphone applications, creating efficiencies in the power grid, driving advancements in healthcare, improving agricultural yields, and helping us find solutions to climate change. With this Tensorflow course, you’ll build expertise in deep learning models, learn to operate TensorFlow to manage neural networks and interpret the results.
You can gain in-depth knowledge of Deep Learning by taking our Deep Learning certification training course. With Simplilearn’s Deep Learning course, you will prepare for a career as a Deep Learning engineer as you master concepts and techniques including supervised and unsupervised learning, mathematical and heuristic aspects, and hands-on modeling to develop algorithms.
Learn more at: https://www.simplilearn.com
It’s long ago, approx. 30 years, since AI was not only a topic for Science-Fiction writers, but also a major research field surrounded with huge hopes and investments. But the over-inflated expectations ended in a subsequent crash and followed by a period of absent funding and interest – the so-called AI winter. However, the last 3 years changed everything – again. Deep learning, a machine learning technique inspired by the human brain, successfully crushed one benchmark after another and tech companies, like Google, Facebook and Microsoft, started to invest billions in AI research. “The pace of progress in artificial general intelligence is incredible fast” (Elon Musk – CEO Tesla & SpaceX) leading to an AI that “would be either the best or the worst thing ever to happen to humanity” (Stephen Hawking – Physicist).
What sparked this new Hype? How is Deep Learning different from previous approaches? Are the advancing AI technologies really a threat for humanity? Let’s look behind the curtain and unravel the reality. This talk will explore why Sundar Pichai (CEO Google) recently announced that “machine learning is a core transformative way by which Google is rethinking everything they are doing” and explain why "Deep Learning is probably one of the most exciting things that is happening in the computer industry” (Jen-Hsun Huang – CEO NVIDIA).
Either a new AI “winter is coming” (Ned Stark – House Stark) or this new wave of innovation might turn out as the “last invention humans ever need to make” (Nick Bostrom – AI Philosoph). Or maybe it’s just another great technology helping humans to achieve more.
This presentation Neural Network will help you understand what is a neural network, how a neural network works, what can the neural network do, types of neural network and a use case implementation on how to classify between photos of dogs and cats. Deep Learning uses advanced computing power and special types of neural networks and applies them to large amounts of data to learn, understand, and identify complicated patterns. Automatic language translation and medical diagnoses are examples of deep learning. Most deep learning methods involve artificial neural networks, modeling how our brains work. Neural networks are built on Machine Learning algorithms to create an advanced computation model that works much like the human brain. This neural network tutorial is designed for beginners to provide them the basics of deep learning. Now, let us deep dive into these slides to understand how a neural network actually work.
Below topics are explained in this neural network presentation:
1. What is Neural Network?
2. What can Neural Network do?
3. How does Neural Network work?
4. Types of Neural Network
5. Use case - To classify between the photos of dogs and cats
Simplilearn’s Deep Learning course will transform you into an expert in deep learning techniques using TensorFlow, the open-source software library designed to conduct machine learning & deep neural network research. With our deep learning course, you'll master deep learning and TensorFlow concepts, learn to implement algorithms, build artificial neural networks and traverse layers of data abstraction to understand the power of data and prepare you for your new role as deep learning scientist.
Why Deep Learning?
It is one of the most popular software platforms used for deep learning and contains powerful tools to help you build and implement artificial neural networks.
Advancements in deep learning are being seen in smartphone applications, creating efficiencies in the power grid, driving advancements in healthcare, improving agricultural yields, and helping us find solutions to climate change. With this Tensorflow course, you’ll build expertise in deep learning models, learn to operate TensorFlow to manage neural networks and interpret the results.
You can gain in-depth knowledge of Deep Learning by taking our Deep Learning certification training course. With Simplilearn’s Deep Learning course, you will prepare for a career as a Deep Learning engineer as you master concepts and techniques including supervised and unsupervised learning, mathematical and heuristic aspects, and hands-on modeling to develop algorithms.
Learn more at: https://www.simplilearn.com
It’s long ago, approx. 30 years, since AI was not only a topic for Science-Fiction writers, but also a major research field surrounded with huge hopes and investments. But the over-inflated expectations ended in a subsequent crash and followed by a period of absent funding and interest – the so-called AI winter. However, the last 3 years changed everything – again. Deep learning, a machine learning technique inspired by the human brain, successfully crushed one benchmark after another and tech companies, like Google, Facebook and Microsoft, started to invest billions in AI research. “The pace of progress in artificial general intelligence is incredible fast” (Elon Musk – CEO Tesla & SpaceX) leading to an AI that “would be either the best or the worst thing ever to happen to humanity” (Stephen Hawking – Physicist).
What sparked this new Hype? How is Deep Learning different from previous approaches? Are the advancing AI technologies really a threat for humanity? Let’s look behind the curtain and unravel the reality. This talk will explore why Sundar Pichai (CEO Google) recently announced that “machine learning is a core transformative way by which Google is rethinking everything they are doing” and explain why "Deep Learning is probably one of the most exciting things that is happening in the computer industry” (Jen-Hsun Huang – CEO NVIDIA).
Either a new AI “winter is coming” (Ned Stark – House Stark) or this new wave of innovation might turn out as the “last invention humans ever need to make” (Nick Bostrom – AI Philosoph). Or maybe it’s just another great technology helping humans to achieve more.
Deep Learning Tutorial | Deep Learning TensorFlow | Deep Learning With Neural...Simplilearn
This Deep Learning presentation will help you in understanding what is Deep Learning, why do we need Deep learning, what is neural network, applications of Deep Learning, what is perceptron, implementing logic gates using perceptron, types of neural networks. At the end of the video, you will get introduced to TensorFlow along with a usecase implementation on recognizing hand-written digits. Deep Learning is inspired by the integral function of the human brain specific to artificial neural networks. These networks, which represent the decision-making process of the brain, use complex algorithms that process data in a non-linear way, learning in an unsupervised manner to make choices based on the input. Deep Learning, on the other hand, uses advanced computing power and special type of neural networks and applies them to large amounts of data to learn, understand, and identify complicated patterns. W will also understand neural networks and how they work in this Deep Learning tutorial video. This Deep Learning tutorial is ideal for professionals with beginner to intermediate level of experience. Now, let us dive deep into this topic and understand what Deep Learning actually is.
Below topics are explained in this Deep Learning presentation:
1. What is Deep Learning?
2. Why do we need Deep Learning?
3. What is Neural network?
4. What is Perceptron?
5. Implementing logic gates using Perceptron
6. Types of Neural networks
7. Applications of Deep Learning
8. Working of Neural network
9. Introduction to TensorFlow
10. Use case implementation using TensorFlow
Simplilearn’s Deep Learning course will transform you into an expert in deep learning techniques using TensorFlow, the open-source software library designed to conduct machine learning & deep neural network research. With our deep learning course, you’ll master deep learning and TensorFlow concepts, learn to implement algorithms, build artificial neural networks and traverse layers of data abstraction to understand the power of data and prepare you for your new role as deep learning scientist.
Why Deep Learning?
It is one of the most popular software platforms used for deep learning and contains powerful tools to help you build and implement artificial neural networks.
Advancements in deep learning are being seen in smartphone applications, creating efficiencies in the power grid, driving advancements in healthcare, improving agricultural yields, and helping us find solutions to climate change.
There is booming demand for skilled deep learning engineers across a wide range of industries, making this deep learning course with TensorFlow training well-suited for professionals at the intermediate to advanced level of experience. We recommend this deep learning online course particularly for the following professionals:
1. Software engineers
2. Data scientists
3. Data analysts
4. Statisticians with an interest in deep learning
What Is Deep Learning? | Introduction to Deep Learning | Deep Learning Tutori...Simplilearn
This Deep Learning Presentation will help you in understanding what is Deep learning, why do we need Deep learning, applications of Deep Learning along with a detailed explanation on Neural Networks and how these Neural Networks work. Deep learning is inspired by the integral function of the human brain specific to artificial neural networks. These networks, which represent the decision-making process of the brain, use complex algorithms that process data in a non-linear way, learning in an unsupervised manner to make choices based on the input. This Deep Learning tutorial is ideal for professionals with beginners to intermediate levels of experience. Now, let us dive deep into this topic and understand what Deep learning actually is.
Below topics are explained in this Deep Learning Presentation:
1. What is Deep Learning?
2. Why do we need Deep Learning?
3. Applications of Deep Learning
4. What is Neural Network?
5. Activation Functions
6. Working of Neural Network
Simplilearn’s Deep Learning course will transform you into an expert in deep learning techniques using TensorFlow, the open-source software library designed to conduct machine learning & deep neural network research. With our deep learning course, you’ll master deep learning and TensorFlow concepts, learn to implement algorithms, build artificial neural networks and traverse layers of data abstraction to understand the power of data and prepare you for your new role as deep learning scientist.
Why Deep Learning?
It is one of the most popular software platforms used for deep learning and contains powerful tools to help you build and implement artificial neural networks.
Advancements in deep learning are being seen in smartphone applications, creating efficiencies in the power grid, driving advancements in healthcare, improving agricultural yields, and helping us find solutions to climate change. With this Tensorflow course, you’ll build expertise in deep learning models, learn to operate TensorFlow to manage neural networks and interpret the results.
You can gain in-depth knowledge of Deep Learning by taking our Deep Learning certification training course. With Simplilearn’s Deep Learning course, you will prepare for a career as a Deep Learning engineer as you master concepts and techniques including supervised and unsupervised learning, mathematical and heuristic aspects, and hands-on modeling to develop algorithms.
There is booming demand for skilled deep learning engineers across a wide range of industries, making this deep learning course with TensorFlow training well-suited for professionals at the intermediate to advanced level of experience. We recommend this deep learning online course particularly for the following professionals:
1. Software engineers
2. Data scientists
3. Data analysts
4. Statisticians with an interest in deep learning
Convolutional Neural Network - CNN | How CNN Works | Deep Learning Course | S...Simplilearn
This presentation on Convolutional neural network tutorial (CNN) will help you understand what is a convolutional neural network, hoe CNN recognizes images, what are layers in the convolutional neural network and at the end, you will see a use case implementation using CNN. CNN is a feed forward neural network that is generally used to analyze visual images by processing data with grid like topology. A CNN is also known as a "ConvNet". Convolutional networks can also perform optical character recognition to digitize text and make natural-language processing possible on analog and hand-written documents. CNNs can also be applied to sound when it is represented visually as a spectrogram. Now, lets deep dive into this presentation to understand what is CNN and how do they actually work.
Below topics are explained in this CNN presentation(Convolutional Neural Network presentation)
1. Introduction to CNN
2. What is a convolutional neural network?
3. How CNN recognizes images?
4. Layers in convolutional neural network
5. Use case implementation using CNN
Simplilearn’s Deep Learning course will transform you into an expert in deep learning techniques using TensorFlow, the open-source software library designed to conduct machine learning & deep neural network research. With our deep learning course, you’ll master deep learning and TensorFlow concepts, learn to implement algorithms, build artificial neural networks and traverse layers of data abstraction to understand the power of data and prepare you for your new role as deep learning scientist.
Why Deep Learning?
It is one of the most popular software platforms used for deep learning and contains powerful tools to help you build and implement artificial neural networks.
Advancements in deep learning are being seen in smartphone applications, creating efficiencies in the power grid, driving advancements in healthcare, improving agricultural yields, and helping us find solutions to climate change. With this Tensorflow course, you’ll build expertise in deep learning models, learn to operate TensorFlow to manage neural networks and interpret the results.
And according to payscale.com, the median salary for engineers with deep learning skills tops $120,000 per year.
You can gain in-depth knowledge of Deep Learning by taking our Deep Learning certification training course. With Simplilearn’s Deep Learning course, you will prepare for a career as a Deep Learning engineer as you master concepts and techniques including supervised and unsupervised learning, mathematical and heuristic aspects, and hands-on modeling to develop algorithms. Those who complete the course will be able to:
Learn more at: https://www.simplilearn.com/
[GomGuard] 뉴런부터 YOLO 까지 - 딥러닝 전반에 대한 이야기JungHyun Hong
뉴런, perceptron, cnn, r-cnn, fast r-cnn, faster r-cnn 및
backpropagation, activation function, batch normalization, cost function, optimizer 등 전반적인 딥뉴럴 네트워크에 대한 지식을 다루고 있습니다.
mail : knholic@gmail.com
blog : gomguard.tistory.com
Convolutional neural network (CNN / ConvNet's) is a part of Computer Vision. Machine Learning Algorithm. Image Classification, Image Detection, Digit Recognition, and many more. https://technoelearn.com .
A comprehensive tutorial on Convolutional Neural Networks (CNN) which talks about the motivation behind CNNs and Deep Learning in general, followed by a description of the various components involved in a typical CNN layer. It explains the theory involved with the different variants used in practice and also, gives a big picture of the whole network by putting everything together.
Next, there's a discussion of the various state-of-the-art frameworks being used to implement CNNs to tackle real-world classification and regression problems.
Finally, the implementation of the CNNs is demonstrated by implementing the paper 'Age ang Gender Classification Using Convolutional Neural Networks' by Hassner (2015).
In machine learning, a convolutional neural network is a class of deep, feed-forward artificial neural networks that have successfully been applied fpr analyzing visual imagery.
AlphaGo: Mastering the Game of Go with Deep Neural Networks and Tree SearchKarel Ha
the presentation of the article "Mastering the game of Go with deep neural networks and tree search" given at the Optimization Seminar 2015/2016
Notes:
- All URLs are clickable.
- All citations are clickable (when hovered over the "year" part of "[author year]").
- To download without a SlideShare account, use https://www.dropbox.com/s/p4rnlhoewbedkjg/AlphaGo.pdf?dl=0
- The corresponding leaflet is available at http://www.slideshare.net/KarelHa1/leaflet-for-the-talk-on-alphago
- The source code is available at https://github.com/mathemage/AlphaGo-presentation
Deep Learning Tutorial | Deep Learning TensorFlow | Deep Learning With Neural...Simplilearn
This Deep Learning presentation will help you in understanding what is Deep Learning, why do we need Deep learning, what is neural network, applications of Deep Learning, what is perceptron, implementing logic gates using perceptron, types of neural networks. At the end of the video, you will get introduced to TensorFlow along with a usecase implementation on recognizing hand-written digits. Deep Learning is inspired by the integral function of the human brain specific to artificial neural networks. These networks, which represent the decision-making process of the brain, use complex algorithms that process data in a non-linear way, learning in an unsupervised manner to make choices based on the input. Deep Learning, on the other hand, uses advanced computing power and special type of neural networks and applies them to large amounts of data to learn, understand, and identify complicated patterns. W will also understand neural networks and how they work in this Deep Learning tutorial video. This Deep Learning tutorial is ideal for professionals with beginner to intermediate level of experience. Now, let us dive deep into this topic and understand what Deep Learning actually is.
Below topics are explained in this Deep Learning presentation:
1. What is Deep Learning?
2. Why do we need Deep Learning?
3. What is Neural network?
4. What is Perceptron?
5. Implementing logic gates using Perceptron
6. Types of Neural networks
7. Applications of Deep Learning
8. Working of Neural network
9. Introduction to TensorFlow
10. Use case implementation using TensorFlow
Simplilearn’s Deep Learning course will transform you into an expert in deep learning techniques using TensorFlow, the open-source software library designed to conduct machine learning & deep neural network research. With our deep learning course, you’ll master deep learning and TensorFlow concepts, learn to implement algorithms, build artificial neural networks and traverse layers of data abstraction to understand the power of data and prepare you for your new role as deep learning scientist.
Why Deep Learning?
It is one of the most popular software platforms used for deep learning and contains powerful tools to help you build and implement artificial neural networks.
Advancements in deep learning are being seen in smartphone applications, creating efficiencies in the power grid, driving advancements in healthcare, improving agricultural yields, and helping us find solutions to climate change.
There is booming demand for skilled deep learning engineers across a wide range of industries, making this deep learning course with TensorFlow training well-suited for professionals at the intermediate to advanced level of experience. We recommend this deep learning online course particularly for the following professionals:
1. Software engineers
2. Data scientists
3. Data analysts
4. Statisticians with an interest in deep learning
What Is Deep Learning? | Introduction to Deep Learning | Deep Learning Tutori...Simplilearn
This Deep Learning Presentation will help you in understanding what is Deep learning, why do we need Deep learning, applications of Deep Learning along with a detailed explanation on Neural Networks and how these Neural Networks work. Deep learning is inspired by the integral function of the human brain specific to artificial neural networks. These networks, which represent the decision-making process of the brain, use complex algorithms that process data in a non-linear way, learning in an unsupervised manner to make choices based on the input. This Deep Learning tutorial is ideal for professionals with beginners to intermediate levels of experience. Now, let us dive deep into this topic and understand what Deep learning actually is.
Below topics are explained in this Deep Learning Presentation:
1. What is Deep Learning?
2. Why do we need Deep Learning?
3. Applications of Deep Learning
4. What is Neural Network?
5. Activation Functions
6. Working of Neural Network
Simplilearn’s Deep Learning course will transform you into an expert in deep learning techniques using TensorFlow, the open-source software library designed to conduct machine learning & deep neural network research. With our deep learning course, you’ll master deep learning and TensorFlow concepts, learn to implement algorithms, build artificial neural networks and traverse layers of data abstraction to understand the power of data and prepare you for your new role as deep learning scientist.
Why Deep Learning?
It is one of the most popular software platforms used for deep learning and contains powerful tools to help you build and implement artificial neural networks.
Advancements in deep learning are being seen in smartphone applications, creating efficiencies in the power grid, driving advancements in healthcare, improving agricultural yields, and helping us find solutions to climate change. With this Tensorflow course, you’ll build expertise in deep learning models, learn to operate TensorFlow to manage neural networks and interpret the results.
You can gain in-depth knowledge of Deep Learning by taking our Deep Learning certification training course. With Simplilearn’s Deep Learning course, you will prepare for a career as a Deep Learning engineer as you master concepts and techniques including supervised and unsupervised learning, mathematical and heuristic aspects, and hands-on modeling to develop algorithms.
There is booming demand for skilled deep learning engineers across a wide range of industries, making this deep learning course with TensorFlow training well-suited for professionals at the intermediate to advanced level of experience. We recommend this deep learning online course particularly for the following professionals:
1. Software engineers
2. Data scientists
3. Data analysts
4. Statisticians with an interest in deep learning
Convolutional Neural Network - CNN | How CNN Works | Deep Learning Course | S...Simplilearn
This presentation on Convolutional neural network tutorial (CNN) will help you understand what is a convolutional neural network, hoe CNN recognizes images, what are layers in the convolutional neural network and at the end, you will see a use case implementation using CNN. CNN is a feed forward neural network that is generally used to analyze visual images by processing data with grid like topology. A CNN is also known as a "ConvNet". Convolutional networks can also perform optical character recognition to digitize text and make natural-language processing possible on analog and hand-written documents. CNNs can also be applied to sound when it is represented visually as a spectrogram. Now, lets deep dive into this presentation to understand what is CNN and how do they actually work.
Below topics are explained in this CNN presentation(Convolutional Neural Network presentation)
1. Introduction to CNN
2. What is a convolutional neural network?
3. How CNN recognizes images?
4. Layers in convolutional neural network
5. Use case implementation using CNN
Simplilearn’s Deep Learning course will transform you into an expert in deep learning techniques using TensorFlow, the open-source software library designed to conduct machine learning & deep neural network research. With our deep learning course, you’ll master deep learning and TensorFlow concepts, learn to implement algorithms, build artificial neural networks and traverse layers of data abstraction to understand the power of data and prepare you for your new role as deep learning scientist.
Why Deep Learning?
It is one of the most popular software platforms used for deep learning and contains powerful tools to help you build and implement artificial neural networks.
Advancements in deep learning are being seen in smartphone applications, creating efficiencies in the power grid, driving advancements in healthcare, improving agricultural yields, and helping us find solutions to climate change. With this Tensorflow course, you’ll build expertise in deep learning models, learn to operate TensorFlow to manage neural networks and interpret the results.
And according to payscale.com, the median salary for engineers with deep learning skills tops $120,000 per year.
You can gain in-depth knowledge of Deep Learning by taking our Deep Learning certification training course. With Simplilearn’s Deep Learning course, you will prepare for a career as a Deep Learning engineer as you master concepts and techniques including supervised and unsupervised learning, mathematical and heuristic aspects, and hands-on modeling to develop algorithms. Those who complete the course will be able to:
Learn more at: https://www.simplilearn.com/
[GomGuard] 뉴런부터 YOLO 까지 - 딥러닝 전반에 대한 이야기JungHyun Hong
뉴런, perceptron, cnn, r-cnn, fast r-cnn, faster r-cnn 및
backpropagation, activation function, batch normalization, cost function, optimizer 등 전반적인 딥뉴럴 네트워크에 대한 지식을 다루고 있습니다.
mail : knholic@gmail.com
blog : gomguard.tistory.com
Convolutional neural network (CNN / ConvNet's) is a part of Computer Vision. Machine Learning Algorithm. Image Classification, Image Detection, Digit Recognition, and many more. https://technoelearn.com .
A comprehensive tutorial on Convolutional Neural Networks (CNN) which talks about the motivation behind CNNs and Deep Learning in general, followed by a description of the various components involved in a typical CNN layer. It explains the theory involved with the different variants used in practice and also, gives a big picture of the whole network by putting everything together.
Next, there's a discussion of the various state-of-the-art frameworks being used to implement CNNs to tackle real-world classification and regression problems.
Finally, the implementation of the CNNs is demonstrated by implementing the paper 'Age ang Gender Classification Using Convolutional Neural Networks' by Hassner (2015).
In machine learning, a convolutional neural network is a class of deep, feed-forward artificial neural networks that have successfully been applied fpr analyzing visual imagery.
AlphaGo: Mastering the Game of Go with Deep Neural Networks and Tree SearchKarel Ha
the presentation of the article "Mastering the game of Go with deep neural networks and tree search" given at the Optimization Seminar 2015/2016
Notes:
- All URLs are clickable.
- All citations are clickable (when hovered over the "year" part of "[author year]").
- To download without a SlideShare account, use https://www.dropbox.com/s/p4rnlhoewbedkjg/AlphaGo.pdf?dl=0
- The corresponding leaflet is available at http://www.slideshare.net/KarelHa1/leaflet-for-the-talk-on-alphago
- The source code is available at https://github.com/mathemage/AlphaGo-presentation
https://telecombcn-dl.github.io/2017-dlai/
Deep learning technologies are at the core of the current revolution in artificial intelligence for multimedia data analysis. The convergence of large-scale annotated datasets and affordable GPU hardware has allowed the training of neural networks for data analysis tasks which were previously addressed with hand-crafted features. Architectures such as convolutional neural networks, recurrent neural networks or Q-nets for reinforcement learning have shaped a brand new scenario in signal processing. This course will cover the basic principles of deep learning from both an algorithmic and computational perspectives.
Slides based on "Introduction to Machine Learning with Python" by Andreas Muller and Sarah Guido for Hongdae Machine Learning Study(https://www.meetup.com/Hongdae-Machine-Learning-Study/) (epoch #2)
홍대 머신 러닝 스터디(https://www.meetup.com/Hongdae-Machine-Learning-Study/) (epoch #2)의 "파이썬 라이브러리를 활용한 머신러닝"(옮긴이 박해선) 슬라이드 자료.
이번 슬라이드는 Graph mining의 기초에 대한 것이다.
고전 문제인 Graph cut에 대한 개념과 수학적인 배경을 설명하고, 이 개념이 clustering (클러스터링)에서 어떻게 사용되는지를 설명한다.
Graph mining, cut, clustring의 기초를 알기에 매우 적합한 자료이다.
2. 신경망
○ 기존의 폰 노이만 컴퓨터 구조를 뛰어 넘기 위해 뇌의 정보 처리를 모방하는 새로운 계
산 모형을 개발하자는 목적(병렬 명령 처리)
○ 연결주의(connectionism) : 단순한 연산을 수행하는 아주 많은 연산기와 그들 간의 아
주 많은 연결을 통해 지능적인 일을 달성하려는 의도의 계산 모형
○ 인공 신경망(Artificial Neural Network)
세포체
수상돌기
축색
다른 뉴런으로부터의 신호를 받음
간단한 연산
다른 뉴런에 신호를 전달
3. ○ 일반화 능력이 뛰어나고, 구현이 쉬움.
○ 신경망은 분류, 예측, 평가, 합성, 제어 등 다양한 분야에 적용할 수 있음.
○ Perceptron
신경망을 분류에 이용한 선형 분류기
Rosenblatt가 제안
선형 분리 가능한 경우에 대해서만 완벽한 분류가 가능
4. STEP1 ) 분류기 구조 정의(수학적 표현) : 𝚯
STEP2 ) 분류기 품질 측정을 위한 비용 함수(cost function) 정의 : 𝑱(𝚯)
STEP3 ) 𝐽(Θ)를 최대 또는 최소로 하는 Θ를 찾기 위한 알고리즘의 설계
학습 알고리즘의 설계
6. Perceptron
○ 신경망을 사용한 선형 분류기
○ 선형 분리가 가능한 경우에 대해서만 완벽한 분류가 가능
Perceptron의 구조
○ 입력 데이터 : 특징 벡터 𝕩 = (𝑥1, … , 𝑥 𝑑)
○ 입력 층 (input layer) : 𝑑 + 1개의 노드
𝑑 : 특징 벡터의 차원
1 : bias(항상 1의 값을 갖는다.)
○ 출력 층 (output layer) : 1개의 노드
○ edge : 입력 층과 출력 층을 연결
가중치를 가진다. (연결 강도, connection strength)
𝑤0 = 𝑏
𝑤1
𝑤2
𝑥0 = 1
𝑥1
𝑥2
𝑥 𝑑
…
𝑤 𝑑
𝑦
입력 층
출력 층
edge
가중치
7. Perceptron에서의 연산
○ 입력 층에서의 연산 : 값을 전달해 주는 연산
○ 출력 층에서의 연산
합 연산
활성 함수 계산
합 연산 𝐬 = 𝒊=𝟏
𝒅
𝒘𝒊 𝒙𝒊 + 𝒃
활성 함수 계산 𝒚 = 𝝉(𝒔)
출력 층에 전달되는 값
- 특징 벡터 𝕩 = (𝑥1, … , 𝑥 𝑑)
- 가중치 벡터 𝕨 = (𝑤1, … , 𝑤 𝑑)
활성 함수 𝜏( . ) : step function
- 𝜏 𝑠 = +1 if 𝑠 ≥ 0
- 𝜏 𝑠 = −1 if 𝑠 < 0
𝑦
𝑥0 = 1
𝑥𝑖
𝑥 𝑑
𝑤0 = 𝑏
𝑤𝑖
𝑤 𝑑
…. ….
8. ○ 연산을 정리해보자. Perceptron에 사용되는 연산은 다음과 같다.
가중치 벡터 : 𝕨 𝑇
= (𝑤1, … , 𝑤 𝑑)
특성 벡터 : 𝕩 𝑇
= (𝑥1, … , 𝑥 𝑑)
연산 :
○ 위에서 정의된 Perceptron은 선형 분류기(linear classifier)에 해당한다. 선형 분류기는
샘플을 2개의 부류 𝐶1, 𝐶2로 분류한다.
선형 분류기가 사용하는 결정 직선 : 𝑑(. )
입력된 샘플에 대한 선형 분류기의 결정 조건 :
𝑦 = 𝜏 𝑠 = 𝜏
𝑖=1
𝑑
𝑤𝑖 𝑥𝑖 + 𝑏 = 𝜏(𝕨 𝑇 𝕩 + 𝑏)
𝜏 𝑠 =
+1, 𝑠 ≥ 0
−1, 𝑠 < 0where
𝑑 𝕩 = 𝕨 𝑇
𝕩 + 𝑏 > 0 이면 𝕩 ∈ 𝐶1
𝑑 𝕩 = 𝕨 𝑇
𝕩 + 𝑏 < 0 이면 𝕩 ∈ 𝐶2
9. 훈련 집합이 𝑋 = { 𝕩1, 𝑡1 , 𝕩2, 𝑡2 , … , (𝕩 𝑁, 𝑡 𝑁)} 주어졌을 때, 이들을 모두 옳게 분류하
는 퍼셉트론 Θ = (𝕨, 𝑏)을 찾아라. 단 샘플은 선형 분리 가능하다.
○ 𝕩 : 특징 벡터
○ 𝑡 : 부류 표지
○ 𝕩𝑖 ∈ 𝐶1 ⇒ 𝕥𝑖 = 1 or −1
How to find?
○ 퍼셉트론 Θ = (𝕨, 𝑏)의 품질을 측정할 수 있는 비용 함수 𝐽(Θ) 정의
○ 비용 함수를 이용하여 품질을 개선시키는 방향으로 학습
비용 함수 𝐽(Θ)
○ 𝑌 : Θ가 틀리게 분류하는 샘플의 집합
○ 𝐽 Θ = 𝐸 = 𝕩 𝑘∈𝑌(−𝑡 𝑘)(𝕨 𝑇
𝕩 𝑘 + 𝑏)
10. 비용 함수 𝐽 Θ = 𝕩 𝑘∈𝑌(−𝑡 𝑘)(𝕨 𝑇
𝕩 𝑘 + 𝑏) 선택의 당위성
○ 샘플 𝕩𝑖가 오분류 되었다고 가정하자.
○ Case 1) 𝑡𝑖 = 1
𝕩𝑖가 오분류 되었으므로, 𝕨 𝑇
𝕩𝑖 + 𝑏의 값은 0보다 작아야 한다.
따라서 𝑡 𝑘 𝕨 𝑇
𝕩 𝑘 + 𝑏 < 0 이다. 이를 통하여 −𝑡 𝑘 𝕨 𝑇
𝕩 𝑘 + 𝑏 > 0임을 알 수 있다.
○ Case 2) 𝑡𝑖 = −1
𝕩𝑖가 오분류 되었으므로, 𝕨 𝑇
𝕩𝑖 + 𝑏의 값은 0보다 커야 한다.
따라서 𝑡 𝑘 𝕨 𝑇
𝕩 𝑘 + 𝑏 < 0 이다. 이를 통하여 −𝑡 𝑘 𝕨 𝑇
𝕩 𝑘 + 𝑏 > 0임을 알 수 있다.
○ 즉, 모든 경우에서 −𝑡 𝑘 𝕨 𝑇
𝕩 𝑘 + 𝑏 > 0이므로,
오분류가 증가할수록 비용 함수의 값은 증가하고,
오분류가 감소할수록 비용 함수의 값은 감소한다.
비용 함수 (Cost function)
11. 비용 함수의 최소값을 찾는 문제 = 잘못 분류된 샘플들의 총 개수를 최소화(0으로)
○ Gradient descent method
Gradient method for 𝕨, 𝑏
○ 𝕨, 𝑏의 초기값에서 시작
○ 비용함수(𝐽(Θ)) 의 값이 감소하는 방향으로𝕨, 𝑏를 이동
𝐽(Θ)를 𝕨, 𝑏로 각각 편미분하여, 기울기의 반대방향으로 𝕨, 𝑏의 값을 이동
시간 𝑡 + 1에서 𝕨, 𝑏의 값(𝜌 : 학습률)
○ 𝕨 𝑡 + 1 = 𝕨 𝑡 − 𝜌
𝜕𝐸
𝜕𝕨
= 𝕨 𝑡 − 𝜌 𝕩 𝒌∈𝒀(−𝒕 𝒌)𝕩 𝒌
○ 𝑏 𝑡 + 1 = 𝑏 𝑡 − 𝜌
𝜕𝐸
𝜕𝑏
= 𝑏 𝑡 − 𝜌 𝕩 𝒌∈𝒀(−𝒕 𝒌)
비용 함수 (Cost function)
12. 입력 : 𝑋 = 𝕩1, 𝕥1 , 𝕩2, 𝕥2 , … , 𝕩 𝑁, 𝕥 𝑁 , 학습률 𝜌
출력 : Perceptron Θ = (𝕨, 𝑏)
알고리즘 :
𝕨, 𝑏를 초기화
repeat {
𝑌 = ∅
for(𝑖 = 1 to 𝑁) {
𝑦 = 𝜏(𝕨 𝑇
𝕩𝑖 + 𝑏);
if (𝑦 ≠ 𝑡𝑖) 𝑌 = 𝑌 ∪ {𝕩𝑖};
}
𝕨 = 𝕨 + 𝜌 𝕩 𝑘∈𝑌 𝑡 𝑘 𝕩 𝑘;
𝑏 = 𝑏 + 𝜌 𝕩 𝑘∈𝑌 𝑡 𝑘 ;
} until (𝑌 = ∅)
𝕨, 𝑏를 출력
배치 모드 (batch mode)
Sample : 선형 분리 가능 - 오분류하는 샘플 수를 0
13. 입력 : 𝑋 = 𝕩1, 𝕥1 , 𝕩2, 𝕥2 , … , 𝕩 𝑁, 𝕥 𝑁 , 학습률 𝜌
출력 : Perceptron Θ = (𝕨, 𝑏)
알고리즘 :
𝕨, 𝑏를 초기화
repeat {
QUIT = true;
for(𝑖 = 1 to 𝑁) {
𝑦 = 𝜏(𝕨 𝑇
𝕩𝑖 + 𝑏);
if (𝑦 ≠ 𝑡𝑖) {
QUIT = false;
𝕨 = 𝕨 + 𝜌𝑡𝑖 𝕩𝑖;
𝑏 = 𝑏 + 𝜌𝑡𝑖;
}
}
} until (QUIT = true)
𝕨, 𝑏를 출력
온라인 모드 (online mode)
𝐽 Θ = −𝑡(𝕨 𝑇
𝕩 + 𝑏)
Sample : 선형 분리 가능 - 오분류하는 샘플 수를 0
14. Batch mode vs Pattern mode
○ Batch mode : 모든 샘플에 대하여 𝕨, 𝑏의 이동량을 계산한 후 𝕨, 𝑏를 한 번 업데이트
○ Online mode : 샘플 각각에 대하여 𝕨, 𝑏의 이동량을 계산한 후 𝕨, 𝑏를 한 번 업데이트
○ Batch mode는 잡음에 둔감하게 해주는 효과
○ Pattern mode가 더 좋은 성능을 보임
20. 이전의 d가
mapping
이전의 a가
mapping
2개의 perceptron을 적용하게 되면 다음과 같이 된다.
이전의 c,b가
mapping
새로 mapping된 포인트에 대하여
새로운 분류직선을 적용해보자.
즉, 새로운 perceptron을 적용해보자.
𝑑3 𝕩 = 𝑢11 𝑧1 + 𝑢21 𝑧2 + 𝑏3
𝑧1
𝑧2
𝑏1
𝑤11
𝑤21
1
𝑥1
𝑥2
− +
𝑏2
𝑤12
𝑤22
𝑏3
𝑢11
𝑢21새로운 분류직선으로 분류를 하게 되면,
우리가 원하는 결과를 얻게 된다.
1
𝑧1
𝑧2
선형분리 불가능 상황
25. Recified Linear Unit (ReLU)
1
𝜏 𝑥 = max(0, 𝑥)
𝜏′
𝑥 = 0 𝑥 ≤ 0 or 1(𝑥 > 0)
Hidden Layer 활성 함수
장점
1) stocastic gradient descent의
가속화가 빠르다. (sigmoid 종류보다)
2) sigmoid 종류의 exponential 연산보다
비용이 싸다. (계산의 복잡성, 시간 측면)
단점
1) training can "die".
즉, 어떤 data point에서도 다시는
activation 되지 않는 update가 발생할
확률이 높다. 40% 정도.
(gradient가 계속 zero value)
27. 몇 개의 층을 둘 것인가?
○ 일반적으로, 은닉 층은 원하는 개수만큼 둘 수 있다.
층간의 연결은 어떻게 할 것인가?
○ 일반적으로, 이웃하지 않은 층간에도 edge를 가질 수 있고, 오른쪽에서 왼쪽으로 가는
피드백 edge를 가질 수도 있다. 일부 노드 간에만 edge가 있는 부분 연결 구조를 가질
수도 있다.
○ FFMLP(feed-forward MLP)
앞으로만 전달되는 구조(전방 다층 퍼셉트론)
가장 보편적으로 사용되는 아키텍쳐
구조 설계 시 고려 사항
28. 각 층에 있는 노드는 몇 개로 할 것인가?
○ 특징 벡터, 부류의 개수는 고정 ⇒ 입력 노드와 출력 노드의 개수는 고정
○ 일반적으로, 최적의 은닉 노드의 수를 추정하는 방법은 없다.
○ 보통 여러 값에 대해 신경망을 훈련하고 그 중 가장 좋은 성능을 보이는 것을 선택
어떤 활성 함수를 사용할 것인가?
○ 일반적으로 노드마다 서로 다른 활성 함수를 사용할 수 있다.
○ 보편적으로는 모든 노드가 같은 활성 함수를 사용한다.
구조 설계 시 고려 사항
29. 훈련 집합이 𝑋 = { 𝕩1, 𝕥1 , 𝕩2, 𝕥2 , … , (𝕩 𝑁, 𝕥 𝑁)} 주어졌을 때, 다중 퍼셉트론(MLP) 𝚯 =
(𝑼, 𝑽)를 찾아라.
○ 𝕩 : 특징 벡터
○ 𝕥 : 부류 표지 벡터(class label vector) or 목적 벡터(target vector)
𝐾 separate binary classification의 경우
▷ 𝕩𝑖 ∈ 𝐶𝑗 ⇒ 𝕥𝑖 = 0, … , 1, … 0 𝑇
or −1, … , 1, … , −1 𝑇
where 𝑗-th position is 1
How to find?
○ 다중 퍼셉트론 Θ = (𝑈, 𝑉)의 품질을 측정할 수 있는 비용 함수 𝐽(Θ) 정의
○ 비용 함수를 이용하여 품질을 개선시키는 방향으로 학습
비용 함수 𝐽(Θ)
○ 𝕩의 label : 𝕥 = (𝑡1, … , 𝑡 𝑚)
○ 𝕩의 perceptron 연산 결과값 : 𝕠 = (𝑜1, … , 𝑜 𝑚)
○ SSE(sum-of-squared errors)
𝐽 Θ = 𝐸 =
1
2
𝑘=1
𝑚
𝑡 𝑘 − 𝑜 𝑘
2
에러
(regression or classification)
활성 함수 : 양극 sigmoid활성 함수 : 이진 sigmoid
31. Output Activation 함수와 Cost 함수는 우리가 해결해야 할 문제의 type에 따라 선택
Regression
○ Output activation function : Linear function
○ Cost function : SSE (Sum-of-squared error)
Classification
○ Binary or 𝐾 separate binary classification
Output activation function : Logistic sigmoid function
Cost function : Cross-entropy
○ Multiclass classification
Output activation function : Softmax function
Cost function : Cross-entropy
Activation 함수 / Cost 함수
32. 비용 함수의 최소값을 찾는 문제 = 에러의 최소값
○ Gradient descent method
Gradient method for 𝑈, 𝑉
○ 𝑈, 𝑉의 초기값에서 시작
○ 비용함수(𝐽(Θ)) 의 값이 감소하는 방향으로 𝑈, 𝑉를 이동
𝐽(Θ)를 𝑈, 𝑉로 각각 편미분하여, 기울기의 반대방향으로 𝑈, 𝑉의 값을 이동
시간 𝑡 + 1에서 𝑈, 𝑉의 값(𝜌 : 학습률)
○ 𝑈 𝑡 + 1 = 𝑈 𝑡 − 𝜌
𝜕𝐸
𝜕𝑈
○ 𝑉 𝑡 + 1 = 𝑉 𝑡 − 𝜌
𝜕𝐸
𝜕𝑉
비용 함수 (Cost function)
33. 입력 : 𝑋 = 𝕩1, 𝕥1 , 𝕩2, 𝕥2 , … , 𝕩 𝑁, 𝕥 𝑁 , 학습률 𝜌
출력 : MLP Θ = (𝑈, 𝑉)
알고리즘 :
𝑈, 𝑉를 초기화
repeat {
for(𝑋의 샘플 각각에 대해) {
for 1 ≤ 𝑗 ≤ 𝑝 : hidden node 𝑧𝑗의 값을 구한다.
for 1 ≤ 𝑘 ≤ 𝑚 : output node 𝑜 𝑘의 값을 구한다.
𝜕𝐸
𝜕𝑈
,
𝜕𝐸
𝜕𝑉
를 구한다. where 𝐸 = 𝐽(Θ)
𝑈 = 𝑈 − 𝜌
𝜕𝐸
𝜕𝑈
, 𝑉 = 𝑉 −
𝜕𝐸
𝜕𝑉
}
} until (멈춤 조건)
𝑈, 𝑉를 출력
전방 계산
(Forward computation)
오류 역전파
(Back propagation)
36. 가중치 초기화
○ 학습이 어떤 초기값을 가지고 출발하느냐는 두 가지 측면에 영향을 미친다.
전역 최적 점으로 수렴 vs 지역 최적 점으로 수렴
수렴 속도
○ 보편적으로, −0.5~0.5의 난수로 설정
○ 일반적인 경우에 대해서, 전역 최적 점을 보장하며 가장 빠르게 수렴하는 초기값을 찾
는 방법은 알려져 있지 않다.
알고리즘 종료 조건
○ 여러 번 실험을 통하여 적절한 반복 회수를 찾아낸다.
○ 한 번의 반복이 종료된 후, 𝑀𝑆𝐸 =
1
𝑁 𝑖=1
𝑁
𝐸𝑖의 값이 미리 설정된 임계값보다 작으면 멈
춘다.
𝐸𝑖 =
1
2 𝑘=1
𝑚
𝑡 𝑘 − 𝑜 𝑘
2
for 𝕩𝑖
지역 최저 점 탈출
○ 다중 시작(multi-start) : 여러 초기값으로 신경망을 훈련하고 그들 중에 가장 좋은 성능
을 보이는 것을 선택
알고리즘 설계 시 고려 사항
37. 입력 : MLP Θ = (𝑈, 𝑉), 미지 패턴 𝕩
출력 : 부류 𝐶 𝑞
알고리즘 :
𝑈, 𝑉를 이용하여 MLP를 설정한다.
for (𝑗 = 1 to 𝑝) {
𝑠𝑢𝑚 𝑧 𝑗
= 𝑖=1
𝑑
𝑢𝑖𝑗 𝑥𝑖 + 𝑢0𝑗;
𝑧𝑗 = 𝜏(𝑠𝑢𝑚 𝑧 𝑗
);
}
for (𝑘 = 1 to 𝑚) {
𝑠𝑢𝑚 𝑜 𝑘
= 𝑗=1
𝑝
𝑣𝑗𝑘 𝑧𝑗 + 𝑣0𝑘;
𝑜 𝑘 = 𝜏(𝑠𝑢𝑚 𝑜 𝑘
);
}
𝕩를 𝑞 = arg max
𝑗
𝑜𝑗 인 𝑤 𝑞로 분류한다.
38. 1. 패턴 인식 - 오일석
2. CS229 Lecture notes : The perceptron and large margin classifiers - Andrew Ng
3. Pattern Recognition and Machine Learning - C.Bishop
4. Machine Learning-A Probabilistic Perspective - Kevin P. Murphy
5. The Elements of Statistical Learning – Trevor Hastie
39. Why SSE?
We consider regression.
우리가 구하고자 하는 target variable를 𝑡 라고 하자.
𝑡 가 Gaussian distribution를 따른다고 가정하면,
𝑷 𝒕 𝕩, 𝕨 = 𝒩(𝑡|𝑦 𝕩, 𝕨 , 𝛽−1
)
즉, 여기서 𝛽는 Gaussian noise의 precision이다. (분산의 역수 값)
Which cost function do we use?
neural network output
(회귀선)
From Bishop's book (page 29)
40. 𝑁 independent, identically distributed obsevation 𝑋 = 𝕩1, … , 𝕩 𝑁 and 𝑇 =
(𝑡1, … , 𝑡 𝑁) 이 주어졌다고 하자.
이에 대응하는 likelihood function은 (회귀에서 우리가 maximize하고 싶은)
𝑷 𝑻 𝑿, 𝕨, 𝜷 =
𝑛=1
𝑁
𝑃(𝑡 𝑛|𝕩 𝑛, 𝕨, 𝛽) =
𝑛=1
𝑁
𝒩(𝑡 𝑛|𝑦 𝕩 𝑛, 𝕨 , 𝛽−1
)
이에 대응하는 negative log likelihood는,
𝛽
2
𝑛=1
𝑁
𝑦 𝕩 𝑛, 𝕨 − 𝑡 𝑛
2 −
𝑁
2
ln 𝛽 +
𝑁
2
ln(2𝜋)
따라서,
1
2
𝑛=1
𝑁
𝑦 𝕩 𝑛, 𝕨 − 𝑡 𝑛
2
를 minimize하는 것과 동일하다. SSE
Which cost function do we use?
41. Why cross-entropy?
We consider binary classification.
우리는 activation 함수로, Logistic sigmoid function을 사용할 것이다.
Binary classification 인 경우, neural network의 output layer는 single target이다.
𝑡 = 1이면 부류 𝐶1에 속할 것이고, 𝑡 = 0이면 부류 𝐶2에 속할 것이다.
output layer의 single target 값을 𝑦(𝕩, 𝕨)라고 하자. 0 ≤ 𝑦 𝕩, 𝕨 ≤ 1 이다.
𝑦 𝕩, 𝕨 값을 𝑃(𝐶1|𝕩), 1 − 𝑦 𝕩, 𝕨 값을 𝑃(𝐶2|𝕩) 라고 할 수 있다.
따라서, likelihood 값, 𝑷(𝒕|𝕩, 𝕨)은 Bernoulli distribution을 따른다.
Which cost function do we use?
42. 𝑷 𝒕 𝕩, 𝕨 = 𝑃 𝐶1 𝕩 𝑡
𝑃 𝐶2 𝕩 1−𝑡
= 𝑦 𝕩, 𝕨 𝑡
1 − 𝑦 𝕩, 𝕨
1−𝑡
likehood function의 값을 극대화하는 문제는 MLE 문제이다.
MLE문제는 negative log likehood를 minimize 하는 문제로 바꿀 수 있다.
즉, − 𝑡 ln 𝑦 𝕩, 𝕨 + 1 − 𝑡 ln 1 − 𝑦 𝕩, 𝕨 의 극소화 문제이다.
이것은 cross-entropy의 형태와 동일하다.
Which cost function do we use?
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