Devoxx 2016 - day 1: notes (2016/11/07)

Deep Learning: An Introduction

Breandan Considine

examples

• ImageNet http://image-net.org/
• voice recognition

reasons

• big data
• hardware (nvidia cuda)
• algorithms

machine learning fundamentals

• tensors: n-dimensional array
• learning types:
  • supervised
  • unsupervised
  • reinforced

tensorflow examples

• linear regression: single line in data
• classification
  • "perceptron"
  • layers + weighs "gradient descent"

unsupervised learning

• clustering, separation, association
• clustering: random points, euclidean distance

data preprocessing

• feature scalin,g normalization
• decomposition & aggregation
• dimensionality reduction
• --> training set, validate & select best modelf

DeepLearning4J

• builder pattern
• components:
  • nd4j -- n-dimensional arrays reinforcement learning
• agent has context + choices
• rewards
• goal: maximize cumulative reward

refs:

• http://www.asimovinstitute.org/neural-network-zoo/
• "Deep learning for Java": https://deeplearning4j.org/ & https://deeplearning4j.org/documentation
• mnist samples of handwriting: http://yann.lecun.com/exdb/mnist/
• combine multiple models https://github.com/google/inception & https://research.googleblog.com/2015/06/inceptionism-going-deeper-into-neural.html -awsome public datasets: https://github.com/caesar0301/awesome-public-datasets

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Make CSS Fun Again with Flexbox!

Hubert Sablonnière

refs:

• https://css-tricks.com/snippets/css/a-guide-to-flexbox/
• autocomplete: http://emmet.io/
• autoprefixer: https://autoprefixer.github.io/

flex:

• float styles are only for text flow
• display: flex: // flex: 1 ( for 1 row)
  • parent / flexcontainer
  • children: elements
• flex-grow: weight
• flex-shrink: minimum
• flex-basis: default

others

• justify-content: center / flex-end
• align-items: center

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Easily secure your Front and back applications with KeyCloak

Sébastien Blanc

http://www.keycloak.org/
Open Source Identity and Access Management

• jwt (rfc 7519)
• openid, kerberos etc
• adapters (wildfly, spring boot, node.js ...)
• native clients
• login brokers
• otp

demo

• web.xml: roles/ security config
• keycloak.json config
• atom editor https://atom.io/
• node.js: add keycloak.protect()

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Sentiment analysis of social media posts using Apache Spark

Niels Dommerholt

http://spark.apache.org/ dataprocessing engine

sentiment analysis

• positive / negative
• java 8 / streams api
• coursera

demo

• JavaSparkContext: config

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Apache Spark? If only it worked

Marcin Szymaniuk

origin: http://blog.explainmydata.com/2014/05/spark-should-be-better-than-mapreduce.html*

details

• RDD: Resilient Distributed Dataset :
  • cache
  • no priority
• sizing executors: configure memory (should autobalance in recent versions)
• known pitfalse: 2g block limit, gc's -- check level of parallelism (groupByKey, repartition)
• check locality: NODE_LOCAL -- increase exectors if needed
• broadcast variable
• avoid groupbykey -- use reducebykey
• debugging:
  • log aggregation
  • hdfs monitoring logging
  • gclogs