All about Big Data Storage and Analytics

Responsible Handling of Data – Process Mining Rule 2 of 4

This is article no. 2 of the four-part article series Privacy, Security and Ethics in Process Mining.

Read this article in German:
Datenschutz, Sicherheit und Ethik beim Process Mining – Regel 2 von 4

Like in any other data analysis technique, you must be careful with the data once you have obtained it. In many projects, nobody thinks about the data handling until it is brought up by the security department. Be that person who thinks about the appropriate level of protection and has a clear plan already prior to the collection of the data.

Do:

  • Have external parties sign a Non Disclosure Agreement (NDA) to ensure the confidentiality of the data. This holds, for example, for consultants you have hired to perform the process mining analysis for you, or for researchers who are participating in your project. Contact your legal department for this. They will have standard NDAs that you can use.
  • Make sure that the hard drive of your laptop, external hard drives, and USB sticks that you use to transfer the data and your analysis results are encrypted.

Don’t:

  • Give the data set to your co-workers before you have checked what is actually in the data. For example, it could be that the data set contains more information than you requested, or that it contains sensitive data that you did not think about. For example, the names of doctors and nurses might be mentioned in a free-text medical notes attribute. Make sure you remove or anonymize (see guideline No. 3) all sensitive data before you pass it on.
  • Upload your data to a cloud-based process mining tool without checking that your organization allows you to upload this kind of data. Instead, use a desktop-based process mining tool (like Disco [3] or ProM [4]) to analyze your data locally or get the cloud-based process mining vendor to set-up an on-premise version of their software within your organization. This is also true for cloud-based storage services like Dropbox: Don’t just store data or analysis results in the cloud even if it is convenient.

Five Illusions about Big Data you can’t help but believe in

Big Data is a smorgasbord of data. Even the marketing world has acknowledged the gravity of Big Data. But alas! Instead of having such a resplendent data power by our side, we are no closer to construct smart marketing decisions than before, when the concept was not well known.

So, something is definitely not right, right? Not all information derived from this industry is precise and to address this issue, I have highlighted five common misconceptions about Big Data. Know it, work on it and gain from it.

 

Misconception 1: Human touch surpasses automation

Entrepreneurs are the ones who pull their weight. The human effort they offer yields potential success for the firm, only if it is backed by meaningful data.
“One of the most common misconceptions is that people believe they will always outperform computers in their decision-making process. That may have been the case in the past, but with the complexity of today’s markets and the advancement of technology, this assumption no longer holds true,” says Victor Rosenman, CEO of Feedvisor, the pioneer of Algo-Commerce. He added, “All business owners are constantly required to make critical decisions, and the most effective decisions are not based on gut feelings, but on facts and data.”

Misconception 2: Data leads to more costs

Money makes a business. It is also the other way round. Using artificial intelligence, small business-owners benefit the most. AI saves time and money both, thus helps in raising the revenues. You need to understand that big data wouldn’t be enjoying the current hot seat status, if it was that expensive to implement. They are low on cost now, even getting lower. Moreover, besides being inexpensive, big data also aid in curbing other costs that the company would have to bear otherwise.

Misconception 3: Data takes the lead in big changes

“The view of cognitive systems as brains that automatically solve any problem is a popular misconception.” – IBM’s Brandon Buckner recently said. Integrated tools are mostly implemented to do stuffs like gauge human expertise and enhance human intelligence. By this, he meant that technologies actually support your business instead of taking the lead. With data, business-owners enjoy better decision-making capabilities, which is propitious for future business endeavours.

Misconception 4: Little data is too little to make any impact

Though big data arrests the glowing eyes, little data seizes the mind.  Little data is a small set of data. We know that people always look for a bulk of information, but at times, quality is not what they seek. Sometimes, little data can do the job, which bulk data fail to do. The information in little data is more restrained, clean and unprecedented.

Misconception 5: Big data for big businesses

No more, you need to shell out ludicrous amounts of money to acquire big data technologies. Non- Fortune 500 companies are also introducing big data in their systems. And the best part is that it is no more confined to a single sector, it is omnipresent in almost every industry.

In 2011 McKinsey Global Institute report called “Big data: The next frontier for innovation, competition, and productivity” revealed: “The use of big data will become a key basis of competition and growth for individual firms.” Now it is 2017, so just think how big Big Data must have grown in size and scope over the past 6 years.

A review of Language Understanding tools – IBM Conversation

In the first part of this series, we saw how top firms with their different assistants are vying to acquire a space in the dialogue market. In this second and final part of this blog-series on Conversational AI, I go more technical to discuss the fundamentals of the underlying concept behind building a Dialogue system i.e. the cornerstone of any Language Understanding tool. Moreover, I explain this by reviewing one such Language Understanding tool as an example that is available in the IBM Bluemix suite, called as IBM Conversation.

IBM Conversation within Bluemix

IBM Conversation was built on the lines of IBM Watson from the IBM Bluemix suite. It is now the for dialogue construction after IBM Dialog was deprecated.We start off by searching and then creating a dedicated environment in the console.

ibm-bluemix-screenshot

Setting up IBM Conversation from the Bluemix Catalog/Console

Basics

Conversation component in IBM Bluemix  is based on the Intent, Entity and Dialogue architecture. And the same is the case with Microsoft LUIS (LUIS stands for Language Understanding Intelligent Service). One of the key components involves doing what is termed as Natural Language Understanding or NLU for short. It extracts words from a textual sentence to understand the grammar dependencies to construct high level semantic information that identifies the underlying intent and entity in the given utterance. It returns a confidence measure i.e. the top-most extracted intent out of the many pre-specified intents that gives us the most likely intent from the given utterance as per our trained model.

These are all statistically/machine learned based on the training data. Go over the demo, tutorial and documentation to get a more in-depth view of things at IBM Conversation.

The intent, entity and dialogue based architecture forms the crux of any SLU system to extract semantic information from speech and enables such a system to be generic across the various Language Understanding toolkits.

alexa-interaction-model-ask-screenshot

The Alexa Interaction model based on intent and slots in ASK

Another huge advantage that ASK provides for building such an architecture, is that it has multi-lingual support.

Conceptual Mapping

Intents can be thought of as classes where one classifies the input examples into one of them. For example,

Call Mark is mapped to the MOBILE class and Navigate to Munich is mapped to the ROUTE class

The entities are labels, so e.g. from above, you can have

Mark as a PERSON and Munich as a CITY.

Major advantage and drawback

Both Conversation and LUIS use a non-Machine Learning based approach for software developers or business users to create a fast prototype. It is definitely easy to begin with and gives a lot of options to create drag and drop based dialogue system. However, it can’t scale up to large data. A hybrid approach that can combine or build a dynamic system on top of this static approach is needed for scalable industry solutions.

Extensions

Moreover, an end to end workflow can be built by plugging in components from Node-RED and introduction to the same can be viewed in the below video.

What’s good is that they have a component for Conversation as well. So, we can build a complete chatbot starting from a speech to text component to get the human commands translated to text, followed by a conversation component to build up the dialog and lastly by a text to speech component to translate this textual dialogue back to speech to be spoken by a humanoid or a mobile device!

Missing components and possible future work

It is not possible to add entities/intent dynamically through the UI after the initial workspace is constructed. The advanced response tab doesn’t allow to edit (add) the entities in the response field, like for example adding variables to the context. We can edit it (highlighted in orange) but it doesn’t save or get reflected.

{
“output”: {
“text”: “I understand you want me to turn on something. You can say turn on the wipers or switch on the lights.”
},
“context”: {
“toppings”: “<? context.toppings.append( ‘onions’ ) ?>”
},
“entities”: {
   “appliance”: “<? entities.appliance.append( ‘mobile’ ) ?>”
}
}

Moreover, the link which only mentions accessing intents and entities but not modifying them.

watson-developer-cloud-screenshot watson-developer-cloud-screenshot2

The only place to add the intent, entities is back in the work space and not programmatically at run time. Perhaps, a possible solution can be to use UI with DB data to save the intermediate and newly discovered intent/entity values and then update the workspace later.

As I end this blog, perhaps there would be another AI assistant released that has moved beyond its embryonic stage to conquer real life application scenarios. Conversational AI is hot property, so dive in to reap its benefits, both from an end user and developer’s perspective!

Note: Hope you enjoyed the read. I have deliberately kept the content a mix of non technical and technical to build the excitement and buzz going around this exciting field of conversational AI! Publishing this blog was on my list as I was compiling lot of facts since last few weeks but I had to hurry even more, given the recent news surrounding this upsurge. As always, any feedback as a comment below or through a message are more than welcome!

Data Science on a large scale – can it be done?

Analytics drives business

In today’s digital world, data has become the crucial success factor for businesses as they seek to maintain a competitive advantage, and there are numerous examples of how companies have found smart ways of monetizing data and deriving value accordingly.

On the one hand, many companies use data analytics to streamline production lines, optimize marketing channels, minimize logistics costs and improve customer retention rates.  These use cases are often described under the umbrella term of operational BI, where decisions are based on data to improve a company’s internal operations, whether that be a company in the manufacturing industry or an e-commerce platform.

On the other hand, over the last few years, a whole range of new service-oriented companies have popped up whose revenue models wholly depend on data analytics.  These Data-Driven Businesses have contributed largely to the ongoing development of new technologies that make it possible to process and analyze large amounts of data to find the right insights.  The better these technologies are leveraged, the better their value-add and the better for their business success.  Indeed, without data and data analytics, they don’t have a business.

Data Science – hype or has it always been around?Druck

In my opinion, there is too much buzz around the new era of data scientists.  Ten years ago, people simply called it data mining, describing similar skills and methods.  What has actually changed is the fact that businesses are now confronted with new types of data sources such as mobile devices and data-driven applications rather than statistical methodologies.  I described that idea in detail in my recent post Let’s replace the Vs of Big Data with a single D.

But, of course, you cannot deny that the importance of these data crunchers has increased significantly. The art of mining data mountains (or perhaps I should say “diving through data lakes”) to find appropriate insights and models and then find the right answers to urgent, business-critical questions has become very popular these days.

The challenge: Data Science with large volumes?

Michael Stonebraker, winner of the Turing Award 2014, has been quoted as saying: “The change will come when business analysts who work with SQL on large amounts of data give way to data EXASOL Pipelinescientists, which will involve more sophisticated analysis, predictive modeling, regressions and Bayesian classification. That stuff at scale doesn’t work well on anyone’s engine right now. If you want to do complex analytics on big data, you have a big problem right now.”

And if you look at the limitations of existing statistical environments out there using R, Python, Java, Julia and other languages, I think he is absolutely right.  Once the data scientists have to handle larger volumes, the tools are just not powerful and scalable enough.  This results in data sampling or aggregation to make statistical algorithms applicable at all.

A new architecture for “Big Data Science”

We at EXASOL have worked hard to develop a smart solution to respond to this challenge.  Imagine that it is possible to use raw data and intelligent statistical models on very large data sets, directly at the place where the data is stored.  Where the data is processed in-memory to achieve optimal performance, all distributed across a powerful MPP cluster of servers, in an environment where you can now “install” the programming language of your choice.

Sounds far-fetched?  If you are not convinced, then I highly recommend you have a look at our brand-new in-database analytic programming platform, which is deeply integrated in our parallel in-memory engine and extensible through using nearly any programming language and statistical library.

For further information on our approach to big data science, go ahead and download a copy of our technical whitepaper:  Big Data Science – The future of analytics.

Neural Nets: Time Series Prediction

Artificial neural networks are very strong universal approximators. Google recently defeated the worlds strongest Go (“chinese chess”) player with two neural nets, which captured the game board as a picture. Aside from these classification tasks, neural nets can be used to predict future values, behaviors or patterns solely based on learned history. In the machine learning literature, this is often referred to as time series prediction, because, you know, values over time need to be predicted. Hah! To illustrate the concept, we will train a neural net to learn the shape of a sinusoidal wave, so it can continue to draw the shape without any help. We will do this with Scala. Scala is a great lang, because it is strongly typed but feels easy like Python. Throughout this article, I will use the library NeuroFlow, which is a simple, lightweight library I wrote to build and train nets. Because Open Source is the way to go, feel free to check (and contribute to? :-)) the code on GitHub.

Introduction of the shape

If we, as humans, want to predict the future based on historic observations, we would have no other chance but to be guided by the shape drawn so far. Let’s study the plot below, asking ourselves: How would a human continue the plot?

sinuspredictdr
f(x) = sin(10*x)

Intuitively, we would keep on oscillating up and down, just like the grey dotted line tries to rough out. To us, the continuation of the shape is reasonably easy to understand, but a machine does not have a gut feeling to ask for a good guess. However, we can summon a Frankenstein, which will be able to learn and continue the shape based on numbers. In order to do so, let’s have a look at the raw, discrete data of our sinusoidal wave:

x f(x)
0.0 0.0
0.05 0.479425538604203
0.10 0.8414709848078965
0.15 0.9974949866040544
0.20 0.9092974268256817
0.25 0.5984721441039564
0.30 0.1411200080598672
0.35 -0.35078322768961984
0.75 0.9379999767747389

Ranging from 0.0 until 0.75, these discrete values drawn from our function with step size 0.05 will be the basis for training. Now, one could come up with the idea to just memorize all values, so a sufficiently reasonable value can be picked based on comparison. For instance, to continue at the point 0.75 in our plot, we could simply examine the area close to 0.15, noticing a similar value close to 1, and hence go downwards. Well, of course this is cheating, but if a good cheat is a superior solution, why not cheat? Being hackers, we wouldn’t care. What’s really limiting here is the fact that the whole data set needs to be kept in memory, which can be infeasible for large sets, plus for more complex shapes, this approach would quickly result in a lot of weird rules and exceptions to be made in order to find comprehensible predictions.

Net to the rescue

Let’s go back to our table and see if a neural net can learn the shape, instead of simply memorizing it. Here, we want our net architecture to be of kind [3, 5, 3, 1]. Three input neurons, two hidden layers with five and three neurons respectively, as well as one neuron for the output layer will capture the data shown in the table.

sinuspredictnet

A supervised training mode means, that we want to train our net with three discrete steps as input and the fourth step as the supervised training element. So we will train a, b, c -> d and e, f, g -> h et cetera, hoping that this way our net will capture the slope pattern of our sinusoidal wave. Let’s code this in Scala:

import neuroflow.core.Activator.Tanh 
import neuroflow.core.WeightProvider.randomWeights 
import neuroflow.nets.DynamicNetwork.constructor

First, we want a Tanh activation function, because the domain of our sinusoidal wave is [-1, 1], just like the hyperbolic tangent. This way we can be sure that we are not comparing apples with oranges. Further, we want a dynamic network (adaptive learning rate) and random initial weights. Let’s put this down:

val fn = Tanh.apply
val sets = Settings(true, 10.0, 0.0000001, 500, None, None, Some(Map("τ" -> 0.25, "c" -> 0.25)))
val net = Network(Input(3) :: Hidden(5, fn) :: Hidden(3, fn) :: Output(1, fn) :: Nil, sets)

No surprises here. After some experiments, we can pick values for the settings instance, which will promise good convergence during training. Now, let’s prepare our discrete steps drawn from the sinus function:

val group = 4
val sinusoidal = Range.Double(0.0, 0.8, 0.05).grouped(group).toList.map(i => i.map(k => (k, Math.sin(10 * k))))
val xsys = sinusoidal.map(s => (s.dropRight(1).map(_._2), s.takeRight(1).map(_._2)))
val xs = xsys.map(_._1)
val ys = xsys.map(_._2)
net.train(xs, ys)

We will draw samples from the range with step size 0.05. After this, we will construct our training values xs as well as our supervised output values ys. Here, a group consists of 4 steps, with 3 steps as input and the last step as the supervised value.

[INFO] [25.01.2016 14:07:51:677] [run-main-5] Taking step 499 - error: 1.4395661497489177E-4  , error per sample: 3.598915374372294E-5
[INFO] [25.01.2016 14:07:51:681] [run-main-5] Took 500 iterations of 500 with error 1.4304189739640242E-4  
[success] Total time: 4 s, completed 25.01.2016 14:20:56

After a pretty short time, we will see good news. Now, how can we check if our net can successfully predict the sinusoidal wave? We can’t simply call our net like a sinus function to map from one input value to one output value, e. g. something like net(0.75) == sin(0.75). Our net does not care about any x values, because it was trained purely based on the function values f(x), or the slope pattern in general. We need to feed our net with a three-dimensional input vector holding the first three, original function values to predict the fourth step, then drop the first original step and append the recently predicted step to predict the fifth step, et cetera. In other words, we need to traverse the net. Let’s code this:

val initial = Range.Double(0.0, 0.15, 0.05).zipWithIndex.map(p => (p._1, xs.head(p._2)))
val result = predict(net, xs.head, 0.15, initial)
result.foreach(r => println(s"${r._1}, ${r._2}"))

with

@tailrec def predict(net: Network, last: Seq[Double], i: Double, results: Seq[(Double, Double)]): Seq[(Double, Double)] = {
  if (i < 4.0) {
    val score = net.evaluate(last).head
    predict(net, last.drop(1) :+ score, i + 0.05, results :+ (i, score))
  } else results
}

So, basically we don’t just continue to draw the sinusoidal shape at the point 0.75, we draw the entire shape right from the start until 4.0 – solely based on our trained net! Now, let’s see how our Frankenstein will complete the sinusoidal shape from 0.75 on:

sinuspredictfintwo

I’d say, pretty neat? Keep in mind, here, the discrete predictions are connected through splines. Another interesting property of our trained net is its prediction compared to the original sinus function when taking the limit towards 4.0. Let’s plot both:

sinuspredictfin

The purple line is the original sinusoidal wave, whereas the green line is the prediction of our net. The first steps show great consistency, but slowly the curves diverge a little over time, as uncertainties will add up. To keep this divergence rather low, one could fine tune settings, for instance numeric precision. However, if one is taking the limit towards infinity, a perfect fit is illusory.

Final thoughts

That’s it! We have trained our net to learn and continue the sinusoidal shape. Now, I know that this is a rather academic example, but to train a neural net to learn more complex shapes is straightforward from here.

Thanks for reading!

A quick primer on TensorFlow – Google’s machine learning workhorse

Introducing Google Brains‘ TensorFlow™

This week started with major news for the machine learning and data science community: the Google Brain Team announced the open sourcing of TensorFlow, their numerical library for tensor network computations. This software is actively developed (and used!) within Google and builds on many of Google’s large scale neural network applications such as automatic image labeling and captioning as well as the speech recognition in Google’s apps.

TensorFlow in bullet points

Here are the main features:

  • Supports deep neural networks – and much more machine learning approaches
  • Highly scalable across many machines and huge data sets
  • Runs on desktops, servers, in cloud and even mobile devices
  • Computation can run on CPUs, GPUs or both
  • All this flexibility is covered by a single API making the execution very streamlined
  • Available interfaces: C++ and Python. More will follow (Java, R, Lua, Go…)
  • Comes with many tools helping to build and visualize the data flow networks
  • Includes a powerful gradient based optimizer with auto-differentiation
  • Extensible with C++
  • Usable for commercial applications – released under Apache Software Licence 2.0

Tensor, what? Tensor, why?

„Numerical library for tensor network computations“ maybe doesn’t sound too exciting, but let’s  consider the implications.

Application of tensors and their networks is a relatively new (but fast evolving) approach in machine learning. Tensors, if you recall your algebra classes, are simply n-dimensional data arrays (so a scalar is a 0th order tensor, a vector is 1st order, and a matrix a 2nd order matrix).

A simple practical example of is color image’s RGB layers (essentially three 2D matrices combined into a 3rd order tensor). Or a more business minded example – if your data source generates a table (a 2D array) every hour, you can look at the full data set as a 3rd order tensor – time being the extra dimension.

Tensor networks then represent “data flow graphs”, where the edges are your multi-dimensional data sets and nodes are the mathematical operations on this data.

Example of of a data flow graph with multiple nodes (data operations). Notice how the execution of nodes is asynchronous. This allows incredible scalability across many machines. Image Source.

Looking at your data through the tensor formalism gives you a lot of powerful tools that were already developed for tensor algebra, allowing fast, complex computations.  

Tensor networks are also a natural fit for computations done on graphical processing units (GPUs) as they are built exactly for the purpose of very fast numerical operations on such a data – speeding up your calculations significantly compared to standard CPU execution!

The importance of flexible architecture & scaling

The data flow graph approach has also further advantages. Most notably, you can split the design of your data flows (i.e. data cleaning, processing, transformations, model building etc.) from its execution. You first build up the graph of your data flow and then you send it to for execution: either on the CPUs of your machines (and it can be your laptop just as well as cluster) or GPUs or a combination. This happens through a single interface that hides all the complexities from you.

Since the execution is asynchronous it scales across many machines and can deal with huge amounts of data.

You can count on the Google guys to build tools not only for academic use, but also heavy-duty operations in the industry!

Is this just another deep learning library?

TensorFlow is of course not the first library to embrace the tensor formalism and GPU execution. The nearest comparisons (and competitors) are Theano, Torch and CGT (Caffe to a limited degree).

While there are significant overlaps between the libraries, TensorFlow tries to provide a broader framework. It is not only a deep learning library – the Data Flow Graphs can incorporate any data processing/analysis applications. It also comes with a very powerful gradient based optimizer with automatic calculations of derivatives offering huge flexibility.

Given this broad vision the closest competitor is probably Theano (while Caffe and the existing Theano wrappers have a narrower focus on deep learning). TensorFlow’s distinguishing feature is that by design its focus is on large, scalable architectures with a complete flexibility in the hardware, best suited for industry/operational use, whereas the other libraries have more academic pedigrees.

Initial analyses also indicate that TensorFlow should bring also performance improvements compared to Theano, although no comprehensive benchmarks have yet been published.

As the other packages are out already for a while, they have large, active communities and often additional supporting software (examples are the very useful wrappers around Theano like Lasagne, Keras and Blocks that provider higher level abstractions to its engine).

Of course, with Google’s gravitas, one can expect that TensorFlow’s open source community will grow very fast and the contributors will quickly add a lot of additional features (and find hidden bugs).

Finally, keep in mind, that while Google provided us with this great data processing framework and some of its machine learning capabilities, it is likely that the most powerful machine learning algorithms still remain Google’s proprietary secret.

Nonetheless, TensorFlow is a huge and very welcome contribution to the open source machine learning world!

Where to go next?

You can find Google’s getting started guide here. The TensorFlow white paper is worth a read too. Source code can be found at the Github page. There is also a Vagrant virtual machine with TensorFlow pre-installed available here.