DOCSLIB.ORG

Tiny Imagenet Challenge

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Tiny Imagenet Challenge Tiny ImageNet Challenge Jiayu Wu Qixiang Zhang Guoxi Xu Stanford University Stanford University Stanford University [email protected] [email protected] [email protected] Abstract Our best model, a fine-tuned Inception-ResNet, achieves a top-1 error rate of 43.10% on test dataset. Moreover, we We present image classification systems using Residual implemented an object localization network based on a Network(ResNet), Inception-Resnet and Very Deep Convo- RNN with LSTM [7] cells, which achieves precise results. lutional Networks(VGGNet) architectures. We apply data In the Experiments and Evaluations section, We will augmentation, dropout and other regularization techniques present thorough analysis on the results, including per-class to prevent over-fitting of our models. What’s more, we error analysis, intermediate output distribution, the impact present error analysis based on per-class accuracy. We of initialization, etc. also explore impact of initialization methods, weight decay and network depth on system performance. Moreover, visu- 2. Related Work alization of intermediate outputs and convolutional filters are shown. Besides, we complete an extra object localiza- Deep convolutional neural networks have enabled the tion system base upon a combination of Recurrent Neural field of image recognition to advance in an unprecedented Network(RNN) and Long Short Term Memroy(LSTM) units. pace over the past decade. Our best classification model achieves a top-1 test error [10] introduces AlexNet, which has 60 million param- rate of 43.10% on the Tiny ImageNet dataset, and our best eters and 650,000 neurons. The model consists of five localization model can localize with high accuracy more convolutional layers, and some of them are followed by than 1 objects, given training images with 1 object labeled. max-pooling layers. To fight overfitting, [10] proposes data augmentation methods and includes the technique of dropout[14] in the model. The model achieves a top-5 er- ror rate of 18.9% in the ILSVRC-2010 contest. A tech- 1. Introduction nique called local response normalization is employed to help generalization, which is similar to the idea of batch The ImageNet Large Scale Visual Recognition Chal- normalization[8]. [13] evaluates a much deeper convo- lenge(ILSVRC) started in 2010 and has become the stan- lutional neural network with smaller filters of size 3×3. dard benchmark of image recognition. Tiny ImageNet As the model goes deeper, the number of filters increases Challenge is a similar challenge with a smaller dataset but while the feature map size decreases by max-pooling. The less image classes. It contains 200 image classes, a training best VGGNet model achieves a top-5 test error of 6.8% dataset of 100,000 images, a validation dataset of 10,000 in ILSVRC-2014. [13] shows that a deeper CNN with images, and a test dataset of 10,000 images. All images are small filters can achieve better results than AlexNet-like of size 64×64. networks. However, as a CNN-based model goes deeper, The goal of our project is to do as well as possible on we have the degradation problem. More specifically, a the image classification problem in Tiny ImageNet Chal- deeper CNN is supposed to have at least the same perfor- lenge. In order to overcome the problem of a small training mance as a shallower CNN, but in practice, a shallower dataset, we applied data augmentation methods to training CNN converges to a lower error rate than a deeper CNN. images, hoping to artificially create variations that help our To solve this problem, [6] proposes ResNet. Residual net- models generalize better. We built our models based on the works are designed to overcome the difficulty of training a idea of VGGNet [13], ResNet [6], and Inception-ResNet deep convolutional neural network. Suppose the mapping [17]. All our image classification models were trained we want to approximate is H : Rn !Rm. Instead of ap- from scratch. We tried a large number of different set- proximating H directly, we approximate a mapping F such tings, including update rules, regularization methods, net- that H(x) = F(x) + x. [6] shows empirically that the map- work depth, number of filters, strength of weight decay, etc. ping F is easier to approximate through training. [6] re- 1 ports their best ResNet achieves a top-5 test error of 3.57% is added between a convolutional layer and its ReLU activa- in ILSVRC-2015. tions. As [6] suggests, batch normalization layers can serve [17] combines inception structures and residual connec- as a source of regularization. Since the random crop gener- tions. Inception-Network is able to achieve better perfor- ated by our data augmentation methods is of size 56×56, mance than traditional residual networks with less parame- although [6] uses 34 or more convolutional layers, we hy- ters. Inception module was introduced by [18]. The basic pothesize that we only need less layers than the models in idea is that we apply different filters and also max-pooling [6] since [6] uses 224×224 image inputs. to the same volume and then concatenate all the output so Unlike [6], we do not use a max pooling layer imme- that each layer can choose the best methods during learning. diately after the first 7×7 convolutional layer because our For object localization, [16] gives a model based on de- input images already have a smaller size than 224×224 in coding an image into a set of people detections. The ap- [6]. Furthermore, our first 7×7 convolutional layer does proach is related to OverFeat model[12], but has some im- not use a stride of 2 like [6]. Each building block for provement. The model relies on LSTM cells to generate our modified ResNet includes 2n convolutional layers with variable length outputs, and the loss function encourages same number of 3×3 filters, where we can adjust the depth the model to make predictions in order of descending con- of the network by varying n. In this project, we have tried fidence. n = 1 and n = 2. Notice that down-sampling is performed at the first layer of each building block by using a stride of 3. Approach 2. 3.1. Data Augmentation Combining two volumes with same dimensions is straightforward. For two volumes with different depths and Preventing overfitting is an essential problem to over- different feature map sizes, [6] suggests two ways to create come, especially for Tiny ImageNet Challenge, because we a shortcut, (A) identity mapping with zero-padding; and (B) only have 500 training images per class 1. a convolutional layer with 1×1 filters with a stride of 2. We First, during training, each time when an image is fed use option (B) for our residual networks. In our project, we to the model, a 56×56 crop randomly generated from the used option (B). Furthermore, when a 1×1 convolution is image will be used instead. During validation and testing, applied, batch normalization is applied to each of the two we use the center crop. incoming volumes before they are merged into one volume. Besides, following [10], we then augment data by hor- Finally, ReLU is applied on the merged volume. izontal flipping, translation and rotation. We also used random contrast correction as an augmentation method. 3.3. Modified Inception-ResNet We set the scaling factor to be random([0:9; 1:08]) at ev- We reorganized the state-of-art Inception-ResNet v2 ery batch, and clip pixel values to the range [0; 255] af- model [17]. The architecture of our modified Inception- ter correction process to guarantee valid augmented im- ResNet model is shown in Fig.3. The input images are first ages. Another data augmentation method we used is ran- down-sampled in a stem module. The stem module has par- dom Gamma correction [11] for luminance adjustment. Af- allel convolutional blocks, whose outputs are later concate- ter some experiments, we used correction coefficient γ = nated. Moreover, one convolutional layer of spatial filter random([0:9; 1:08]), which ensures both significant lumi- size 1×7 and one of size 7×1 are combined to replace a nance change and recognizable augmented images. Fig. 1 7×7 sized layer, which significantly reduces number of pa- gives concrete instances of above methods. rameters while maintaining same receptive field. Then the In order to speed up the training process, we apply these data flows through n Inception-Resnet-A modules, which methods in a random fashion. When an image is fed to the has the residual part being an inception module. A 1×1 model, every augmentation method is applied randomly to convolutional layer is applied at the end of each inception this image. In this way, the total number of training ex- module to keep the output depth same as the input’s, thus amples is the same but we managed to have our models enabling the final addition operation. Then after another see slightly different but highly recognizable images at each down-sampling in a reduction module, the feature map flow epoch. passes through 2n Inception-Resnet-B modules and finally 3.2. Modified Residual Network reaches a fully connected layer. Fig.3 also shows several modifications we made to fit Fig. 2 shows the architecture of our modified ResNet. It the Inception-Resnet model with the tiny ImageNet chal- consists of a series of convolutional layers of different num- lenge. Firstly, we used 2 Inception-Resnet module types ber of filters, an average pooling layer, and finally a fully- and 1 reduction module, while [17] uses 3 Inception-Resnet connected affine scoring layer. A batch normalization layer module types and 2 reduction modules.
Load more

Recommended publications
  • Backpropagation and Deep Learning in the Brain
    Backpropagation and Deep Learning in the Brain Simons Institute -- Computational Theories of the Brain 2018 Timothy Lillicrap DeepMind, UCL With: Sergey Bartunov, Adam Santoro, Jordan Guerguiev, Blake Richards, Luke Marris, Daniel Cownden, Colin Akerman, Douglas Tweed, Geoffrey Hinton The “credit assignment” problem The solution in artificial networks: backprop Credit assignment by backprop works well in practice and shows up in virtually all of the state-of-the-art supervised, unsupervised, and reinforcement learning algorithms. Why Isn’t Backprop “Biologically Plausible”? Why Isn’t Backprop “Biologically Plausible”? Neuroscience Evidence for Backprop in the Brain? A spectrum of credit assignment algorithms: A spectrum of credit assignment algorithms: A spectrum of credit assignment algorithms: How to convince a neuroscientist that the cortex is learning via [something like] backprop - To convince a machine learning researcher, an appeal to variance in gradient estimates might be enough. - But this is rarely enough to convince a neuroscientist. - So what lines of argument help? How to convince a neuroscientist that the cortex is learning via [something like] backprop - What do I mean by “something like backprop”?: - That learning is achieved across multiple layers by sending information from neurons closer to the output back to “earlier” layers to help compute their synaptic updates. How to convince a neuroscientist that the cortex is learning via [something like] backprop 1. Feedback connections in cortex are ubiquitous and modify the
    [Show full text]
  • Automated Elastic Pipelining for Distributed Training of Transformers
    PipeTransformer: Automated Elastic Pipelining for Distributed Training of Transformers Chaoyang He 1 Shen Li 2 Mahdi Soltanolkotabi 1 Salman Avestimehr 1 Abstract the-art convolutional networks ResNet-152 (He et al., 2016) and EfficientNet (Tan & Le, 2019). To tackle the growth in The size of Transformer models is growing at an model sizes, researchers have proposed various distributed unprecedented rate. It has taken less than one training techniques, including parameter servers (Li et al., year to reach trillion-level parameters since the 2014; Jiang et al., 2020; Kim et al., 2019), pipeline paral- release of GPT-3 (175B). Training such models lel (Huang et al., 2019; Park et al., 2020; Narayanan et al., requires both substantial engineering efforts and 2019), intra-layer parallel (Lepikhin et al., 2020; Shazeer enormous computing resources, which are luxu- et al., 2018; Shoeybi et al., 2019), and zero redundancy data ries most research teams cannot afford. In this parallel (Rajbhandari et al., 2019). paper, we propose PipeTransformer, which leverages automated elastic pipelining for effi- T0 (0% trained) T1 (35% trained) T2 (75% trained) T3 (100% trained) cient distributed training of Transformer models. In PipeTransformer, we design an adaptive on the fly freeze algorithm that can identify and freeze some layers gradually during training, and an elastic pipelining system that can dynamically Layer (end of training) Layer (end of training) Layer (end of training) Layer (end of training) Similarity score allocate resources to train the remaining active layers. More specifically, PipeTransformer automatically excludes frozen layers from the Figure 1. Interpretable Freeze Training: DNNs converge bottom pipeline, packs active layers into fewer GPUs, up (Results on CIFAR10 using ResNet).
    [Show full text]
  • Convolutional Neural Network Transfer Learning for Robust Face
    Convolutional Neural Network Transfer Learning for Robust Face Recognition in NAO Humanoid Robot Daniel Bussey1, Alex Glandon2, Lasitha Vidyaratne2, Mahbubul Alam2, Khan Iftekharuddin2 1Embry-Riddle Aeronautical University, 2Old Dominion University Background Research Approach Results • Artificial Neural Networks • Retrain AlexNet on the CASIA-WebFace dataset to configure the neural • VGG-Face Shows better results in every performance benchmark measured • Computing systems whose model architecture is inspired by biological networf for face recognition tasks. compared to AlexNet, although AlexNet is able to extract features from an neural networks [1]. image 800% faster than VGG-Face • Capable of improving task performance without task-specific • Acquire an input image using NAO’s camera or a high resolution camera to programming. run through the convolutional neural network. • Resolution of the input image does not have a statistically significant impact • Show excellent performance at classification based tasks such as face on the performance of VGG-Face and AlexNet. recognition [2], text recognition [3], and natural language processing • Extract the features of the input image using the neural networks AlexNet [4]. and VGG-Face • AlexNet’s performance decreases with respect to distance from the camera where VGG-Face shows no performance loss. • Deep Learning • Compare the features of the input image to the features of each image in the • A subfield of machine learning that focuses on algorithms inspired by people database. • Both frameworks show excellent performance when eliminating false the function and structure of the brain called artificial neural networks. positives. The method used to allow computers to learn through a process called • Determine whether a match is detected or if the input image is a photo of a training.
    [Show full text]
  • Deep Learning Is Robust to Massive Label Noise
    Deep Learning is Robust to Massive Label Noise David Rolnick * 1 Andreas Veit * 2 Serge Belongie 2 Nir Shavit 3 Abstract Thus, annotation can be expensive and, for tasks requiring expert knowledge, may simply be unattainable at scale. Deep neural networks trained on large supervised datasets have led to impressive results in image To address this limitation, other training paradigms have classification and other tasks. However, well- been investigated to alleviate the need for expensive an- annotated datasets can be time-consuming and notations, such as unsupervised learning (Le, 2013), self- expensive to collect, lending increased interest to supervised learning (Pinto et al., 2016; Wang & Gupta, larger but noisy datasets that are more easily ob- 2015) and learning from noisy annotations (Joulin et al., tained. In this paper, we show that deep neural net- 2016; Natarajan et al., 2013; Veit et al., 2017). Very large works are capable of generalizing from training datasets (e.g., Krasin et al.(2016); Thomee et al.(2016)) data for which true labels are massively outnum- can often be obtained, for example from web sources, with bered by incorrect labels. We demonstrate remark- partial or unreliable annotation. This can allow neural net- ably high test performance after training on cor- works to be trained on a much wider variety of tasks or rupted data from MNIST, CIFAR, and ImageNet. classes and with less manual effort. The good performance For example, on MNIST we obtain test accuracy obtained from these large, noisy datasets indicates that deep above 90 percent even after each clean training learning approaches can tolerate modest amounts of noise example has been diluted with 100 randomly- in the training set.
    [Show full text]
  • The History Began from Alexnet: a Comprehensive Survey on Deep Learning Approaches
    > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 1 The History Began from AlexNet: A Comprehensive Survey on Deep Learning Approaches Md Zahangir Alom1, Tarek M. Taha1, Chris Yakopcic1, Stefan Westberg1, Paheding Sidike2, Mst Shamima Nasrin1, Brian C Van Essen3, Abdul A S. Awwal3, and Vijayan K. Asari1 Abstract—In recent years, deep learning has garnered I. INTRODUCTION tremendous success in a variety of application domains. This new ince the 1950s, a small subset of Artificial Intelligence (AI), field of machine learning has been growing rapidly, and has been applied to most traditional application domains, as well as some S often called Machine Learning (ML), has revolutionized new areas that present more opportunities. Different methods several fields in the last few decades. Neural Networks have been proposed based on different categories of learning, (NN) are a subfield of ML, and it was this subfield that spawned including supervised, semi-supervised, and un-supervised Deep Learning (DL). Since its inception DL has been creating learning. Experimental results show state-of-the-art performance ever larger disruptions, showing outstanding success in almost using deep learning when compared to traditional machine every application domain. Fig. 1 shows, the taxonomy of AI. learning approaches in the fields of image processing, computer DL (using either deep architecture of learning or hierarchical vision, speech recognition, machine translation, art, medical learning approaches) is a class of ML developed largely from imaging, medical information processing, robotics and control, 2006 onward. Learning is a procedure consisting of estimating bio-informatics, natural language processing (NLP), cybersecurity, and many others.
    [Show full text]
  • Kernel Descriptors for Visual Recognition
    Kernel Descriptors for Visual Recognition Liefeng Bo University of Washington Seattle WA 98195, USA Xiaofeng Ren Dieter Fox Intel Labs Seattle University of Washington & Intel Labs Seattle Seattle WA 98105, USA Seattle WA 98195 & 98105, USA Abstract The design of low-level image features is critical for computer vision algorithms. Orientation histograms, such as those in SIFT [16] and HOG [3], are the most successful and popular features for visual object and scene recognition. We high- light the kernel view of orientation histograms, and show that they are equivalent to a certain type of match kernels over image patches. This novel view allows us to design a family of kernel descriptors which provide a unified and princi- pled framework to turn pixel attributes (gradient, color, local binary pattern, etc.) into compact patch-level features. In particular, we introduce three types of match kernels to measure similarities between image patches, and construct compact low-dimensional kernel descriptors from these match kernels using kernel princi- pal component analysis (KPCA) [23]. Kernel descriptors are easy to design and can turn any type of pixel attribute into patch-level features. They outperform carefully tuned and sophisticated features including SIFT and deep belief net- works. We report superior performance on standard image classification bench- marks: Scene-15, Caltech-101, CIFAR10 and CIFAR10-ImageNet. 1 Introduction Image representation (features) is arguably the most fundamental task in computer vision. The problem is highly challenging because images exhibit high variations, are highly structured, and lie in high dimensional spaces. In the past ten years, a large number of low-level features over images have been proposed.
    [Show full text]
  • Face Recognition Using Popular Deep Net Architectures: a Brief Comparative Study
    future internet Article Face Recognition Using Popular Deep Net Architectures: A Brief Comparative Study Tony Gwyn 1,* , Kaushik Roy 1 and Mustafa Atay 2 1 Department of Computer Science, North Carolina A&T State University, Greensboro, NC 27411, USA; [email protected] 2 Department of Computer Science, Winston-Salem State University, Winston-Salem, NC 27110, USA; [email protected] * Correspondence: [email protected] Abstract: In the realm of computer security, the username/password standard is becoming increas- ingly antiquated. Usage of the same username and password across various accounts can leave a user open to potential vulnerabilities. Authentication methods of the future need to maintain the ability to provide secure access without a reduction in speed. Facial recognition technologies are quickly becoming integral parts of user security, allowing for a secondary level of user authentication. Augmenting traditional username and password security with facial biometrics has already seen impressive results; however, studying these techniques is necessary to determine how effective these methods are within various parameters. A Convolutional Neural Network (CNN) is a powerful classification approach which is often used for image identification and verification. Quite recently, CNNs have shown great promise in the area of facial image recognition. The comparative study proposed in this paper offers an in-depth analysis of several state-of-the-art deep learning based- facial recognition technologies, to determine via accuracy and other metrics which of those are most effective. In our study, VGG-16 and VGG-19 showed the highest levels of image recognition accuracy, Citation: Gwyn, T.; Roy, K.; Atay, M. as well as F1-Score.
    [Show full text]
  • Key Ideas and Architectures in Deep Learning Applications That (Probably) Use DL
    Key Ideas and Architectures in Deep Learning Applications that (probably) use DL Autonomous Driving Scene understanding /Segmentation Applications that (probably) use DL WordLens Prisma Outline of today’s talk Image Recognition Fun application using CNNs ● LeNet - 1998 ● Image Style Transfer ● AlexNet - 2012 ● VGGNet - 2014 ● GoogLeNet - 2014 ● ResNet - 2015 Questions to ask about each architecture/ paper Special Layers Non-Linearity Loss function Weight-update rule Train faster? Reduce parameters Reduce Overfitting Help you visualize? LeNet5 - 1998 LeNet5 - Specs MNIST - 60,000 training, 10,000 testing Input is 32x32 image 8 layers 60,000 parameters Few hours to train on a laptop Modified LeNet Architecture - Assignment 3 Training Input Forward pass Maxp Max Conv ReLU Conv ReLU FC ReLU Softmax ool pool Backpropagation - Labels Loss update weights Modified LeNet Architecture - Assignment 3 Testing Input Forward pass Maxp Max Conv ReLU Conv ReLU FC ReLU Softmax ool pool Output Compare output with labels Modified LeNet - CONV Layer 1 Input - 28 x 28 Output - 6 feature maps - each 24 x 24 Convolution filter - 5 x 5 x 1 (convolution) + 1 (bias) How many parameters in this layer? Modified LeNet - CONV Layer 1 Input - 32 x 32 Output - 6 feature maps - each 28 x 28 Convolution filter - 5 x 5 x 1 (convolution) + 1 (bias) How many parameters in this layer? (5x5x1+1)*6 = 156 Modified LeNet - Max-pooling layer Decreases the spatial extent of the feature maps, makes it translation-invariant Input - 28 x 28 x 6 volume Maxpooling with filter size 2
    [Show full text]
  • Transfer Learning Based Face Recognition Using Deep Learning M
    International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-8 Issue-1S3, June 2019 Transfer Learning based Face Recognition using Deep Learning M. Madhu Latha, K. V. Krishnam Raju Abstract: Face Recognition technology is advancing rapidly learning also called as a hierarchical learning widespread as a with the current developments in computer vision. Face new area of the machine learning research. Deep learning Recognition can be done either in a single image or from a technique is a type of machine learning that gives computer tracked video. The task of face recognition can be improved with systems an ability to improve with knowledge and data. the recent surge of interest in the deep learning architectures. In Deep learning has attained great power and flexibility by this paper we proposed an Inception-V3 CNN using an approach representing knowledge. called Transfer learning. Deep learning algorithms are trained to solve specific tasks and designed to work in isolated. The idea of Nowadays Face Recognition [2] has legitimately broken transfer learning is to overcome isolated learning and leveraging in to widespread and benefits became more and more knowledge acquired from one task to solve the related ones. Thus, tangible. Face Recognition is the eminent biometric instead of training CNN from scratch we use Google’s pretrained technique extensively used in many areas in daily life such as Inception v3 model by applying transfer learning. Inception v3 military, finance, public security, etc. Face recognition is the model was trained on ImageNet dataset and transferred its outstanding research topic under the area of computer vision.
    [Show full text]
  • Transfer Imagenet for Medical Image Analyzing Using Unsupervised Learning
    Transfer ImageNet for Medical Image Analyzing Using Unsupervised Learning Ning Wang and Peng Chu Abstract˗˗Convolutional Neural Network (CNN) is powerful tool for image analyzing. It has demonstrated its success in multiple tasks. But requirement of large amount of annotated samples prohibits its widely using in medical image analyzing. This project explores using unsupervised convolutional auto-encoder (CAE) for fine-tuning CNN trained on ImageNet for medical images analyzing. The fine-tuned CNN then is test on a task for landmark estimation. Compared with CNN without unsupervised fine-tuning, CNN adjusted by CAE achieves 22% less average error on four landmarks. I. Introduction Deep neural network recently becomes a popular way for learning knowledge from massive annotated database. It shows great success in multiple tasks such as image classification and playing the board game Go. Specifically, convolutional neural network (CNN) which is believed to have mimicked the mammal visual vortex is the most widely used framework and achieves stat-of-art performance on the ImageNet classification [1] and AlphaGo project [2]. (a) (b) Figure 1: Image samples from (a) CIFAR10 and (b) Dental X-ray images. The CNN is usually trained on gradient descent algorithm which is a supervised process. Thus annotated date is require for the training process. A popular CNN configuration for ImageNet classification named ‘VGG-16’ has 138 million free parameters for training [3]. Fortunately, ImageNet also has over 10 million annotated images [4]. But for ordinary task, there is usually no such huge amount of annotated database for training. A popular way to solve this problem is to transfer knowledge learned on ImageNet to other domain by using small amount of annotated date to fine-tuning the network learned on ImageNet [6].
    [Show full text]
  • Generation-Distillation for Efficient Natural Language Understanding in Low-Data Settings
    Generation-Distillation for Efficient Natural Language Understanding in Low-Data Settings Luke Melas-Kyriazi George Han Celine Liang [email protected] [email protected] [email protected] Abstract et al., 2018; Rajpurkar et al., 2016). The now- common approach for employing these systems Over the past year, the emergence of trans- using transfer learning is to (1) pretrain a large fer learning with large-scale language mod- language model (LM), (2) replace the top layer of els (LM) has led to dramatic performance im- the LM with a task-specific layer, and (3) finetune provements across a broad range of natural language understanding tasks. However, the the entire model on a (usually relatively small) size and memory footprint of these large LMs labeled dataset. Following this pattern, Peters makes them difficult to deploy in many sce- et al.(2018), Howard and Ruder(2018), Radford narios (e.g. on mobile phones). Recent re- et al.(2019), and Devlin et al.(2018) broadly out- search points to knowledge distillation as a perform standard task-specific NLU models (i.e. potential solution, showing that when train- CNNs/LSTMs), which are initialized from scratch ing data for a given task is abundant, it is (or only from word embeddings) and trained on possible to distill a large (teacher) LM into a small task-specific (student) network with the available labeled data. minimal loss of performance. However, when Notably, transfer learning with LMs vastly out- such data is scarce, there remains a signifi- performs training task-specific from scratch in low cant performance gap between large pretrained data regimes.
    [Show full text]
  • Imagenet Classification with Deep Convolutional Neural Networks
    ImageNet Classification with Deep Convolutional Neural Networks Alex Krizhevsky Ilya Sutskever Geoffrey E. Hinton University of Toronto University of Toronto University of Toronto [email protected] [email protected] [email protected] Abstract We trained a large, deep convolutional neural network to classify the 1.2 million high-resolution images in the ImageNet LSVRC-2010 contest into the 1000 dif- ferent classes. On the test data, we achieved top-1 and top-5 error rates of 37.5% and 17.0% which is considerably better than the previous state-of-the-art. The neural network, which has 60 million parameters and 650,000 neurons, consists of five convolutional layers, some of which are followed by max-pooling layers, and three fully-connected layers with a final 1000-way softmax. To make train- ing faster, we used non-saturating neurons and a very efficient GPU implemen- tation of the convolution operation. To reduce overfitting in the fully-connected layers we employed a recently-developed regularization method called “dropout” that proved to be very effective. We also entered a variant of this model in the ILSVRC-2012 competition and achieved a winning top-5 test error rate of 15.3%, compared to 26.2% achieved by the second-best entry. 1 Introduction Current approaches to object recognition make essential use of machine learning methods. To im- prove their performance, we can collect larger datasets, learn more powerful models, and use bet- ter techniques for preventing overfitting. Until recently, datasets of labeled images were relatively small — on the order of tens of thousands of images (e.g., NORB [16], Caltech-101/256 [8, 9], and CIFAR-10/100 [12]).
    [Show full text]