Short-Term Memory Optimization in Recurrent Neural Networks by Autoencoder-based Initialization

Training RNNs to learn long-term dependencies is difficult due to vanishing gradients. We explore an alternative solution based on explicit memorization using linear autoencoders for sequences, which allows to maximize the short-term memory and that can be solved with a closed-form solution without backpropagation… We introduce an initialization schema that pretrains the weights of a recurrent neural network to approximate the linear autoencoder of the input sequences and we show how such pretraining can better support solving hard classification tasks […]

Read more

Efficient Online Learning of Optimal Rankings: Dimensionality Reduction via Gradient Descent

We consider a natural model of online preference aggregation, where sets of preferred items $R_1, R_2, ldots, R_t$ along with a demand for $k_t$ items in each $R_t$, appear online. Without prior knowledge of $(R_t, k_t)$, the learner maintains a ranking $pi_t$ aiming that at least $k_t$ items from $R_t$ appear high in $pi_t$… This is a fundamental problem in preference aggregation with applications to, e.g., ordering product or news items in web pages based on user scrolling and click […]

Read more

CODER: Knowledge infused cross-lingual medical term embedding for term normalization

We propose a novel medical term embedding method named CODER, which stands for mediCal knOwledge embeDded tErm Representation. CODER is designed for medical term normalization by providing close vector representations for terms that represent the same or similar concepts with multi-language support… CODER is trained on top of BERT (Devlin et al., 2018) with the innovation that token vector aggregation is trained using relations from the UMLS Metathesaurus (Bodenreider, 2004), which is a comprehensive medical knowledge graph with multi-language support. […]

Read more

Intriguing Properties of Contrastive Losses

Contrastive loss and its variants have become very popular recently for learning visual representations without supervision. In this work, we first generalize the standard contrastive loss based on cross entropy to a broader family of losses that share an abstract form of $mathcal{L}_{text{alignment}} + lambda mathcal{L}_{text{distribution}}$, where hidden representations are encouraged to (1) be aligned under some transformations/augmentations, and (2) match a prior distribution of high entropy… We show that various instantiations of the generalized loss perform similarly under the […]

Read more

Time-dependent Performance Analysis of the 802.11p-based Platooning Communications Under Disturbance

Platooning is a critical technology to realize autonomous driving. Each vehicle in platoons adopts the IEEE 802.11p standard to exchange information through communications to maintain the string stability of platoons… However, one vehicle in platoons inevitably suffers from a disturbance resulting from the leader vehicle acceleration/deceleration, wind gust and uncertainties in a platoon control system, i.e., aerodynamics drag and rolling resistance moment etc. Disturbances acting on one vehicle may inevitably affect the following vehicles and cause that the spacing error […]

Read more

Gradient Descent in Python: Implementation and Theory

Introduction This tutorial is an introduction to a simple optimization technique called gradient descent, which has seen major application in state-of-the-art machine learning models. We’ll develop a general purpose routine to implement gradient descent and apply it to solve different problems, including classification via supervised learning. In this process, we’ll gain an insight into the working of this algorithm and study the effect of various hyper-parameters on its performance. We’ll also go over batch and stochastic gradient descent variants as […]

Read more

Framework to build a niche dictionary for text mining

Having the right dictionary is at the heart of any text mining analysis. Dictionary for text mining can be compared to maps while travelling in a new city. The more precise and accurate maps you use, the faster you reach to the destination. On the other hand, a wrong or incomplete map can end up confusing the traveler. Use of dictionary helps us convert unstructured text into structured data. The more precise dictionary you have for the analysis, the more accurate […]

Read more

Tapping Twitter Sentiments: A Complete Case-Study on 2015 Chennai Floods

Introduction We did this case study as a part of our capstone project at Great Lakes Institute of Management, Chennai. After we presented this study, we got an overwhelming response from our professors & mentors. Later, they encouraged us to share our work to help others learn something new. We’ve been following Analytics Vidhya for a while now. Everyone knows, it’s probably the largest engine to share analytics knowledge. We tried and got lucky in connecting with their content team. So, […]

Read more

An Intuitive Understanding of Word Embeddings: From Count Vectors to Word2Vec

Introduction Before we start, have a look at the below examples. You open Google and search for a news article on the ongoing Champions trophy and get hundreds of search results in return about it. Nate silver analysed millions of tweets and correctly predicted the results of 49 out of 50 states in 2008 U.S Presidential Elections. You type a sentence in google translate in English and get an Equivalent Chinese conversion.   So what do the above examples have […]

Read more

The Ultimate Learning Path to Becoming a Data Scientist in 2018

Introduction So you’ve taken the plunge. You want to become a data scientist. But where to begin? There are far too many resources out there. How do you decide the starting point? Did you miss out on topics you should have studied? Which are the best resources to learn? Don’t worry, we have you covered! Analytics Vidhya’s learning path for 2016 saw 250,000+ views. In 2017, we went even further and saw an incredible 500,000+ views! So this year, we […]

Read more
1 727 728 729 730 731 906