Posts tagged "project"

Towards Automatic Machine Learning Pipeline Design

I recently finished my PhD thesis and is now available online. Most of the code related to the thesis is available in this repository.

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Reactive queries in PostgreSQL

I am a big fan of the application architecture promoted by Meteor. I like declarative programming. You describe what you want and not how and the system does the rest. Reactive programming is very similar. You define how outputs should be computed from inputs, but when is this computed and how it is composed with other computations is left to the system. So you can define what is read from the database and send to the client. And how it is read on the client and transformed and send to the UI library. And then UI library can render this data. And every time something changes, the rest gets automatically recomputed, refreshed, re-rendered.

Meteor is tightly linked with MongoDB. They developed a complex piece of technology to provide reactive queries. Reactive queries are queries which after providing initial results they also continue providing any changes to those results as input data used in queries change. While I like MongoDB, I still prefer consistency tools provided by traditional SQL databases: transactions, foreign keys, joins and triggers. They are close to declarative programming as well. You define relations between data once and then the system makes sure data is consistent. I had to implement many of those features on top of MongoDB, like my package PeerDB.

This is why I made reactive-postgres node.js package. It provides exactly such reactive queries, but for PostgreSQL open source database. Its API is simple, on purpose, and because it should be. You provide a query, you get initial data, and then you get all changes. Try it out.

Proof of luck consensus protocol and Luckychain blockchain

Proof of work consensus protocol used in modern cryptocurrencies like Bitcoin and Ethereum consumes a lot of energy and requires participants to use their CPUs for mining instead of other useful work. But exactly this cost is why it is works to prevent Sybil attacks. One cannot participate in the selection of the next block without paying this cost, which makes the issue of puppet participants trying to influence block selection irrelevant, because they also have to do the work, and pay the cost.

In recent Intel CPUs a new set of instructions is available, SGX, which allows one to run code inside a special environment where even operating system cannot change its execution. In the paper we published (arXiv, Cryptology ePrint Archive) we explore consensus protocol designs using the Intel SGX technology, with the goal of making blockchain participation energy efficient, with low CPU usage, and to democratize mining so that participants can participate again with their general purpose computers (with Intel CPUs) instead of only with specialized ASICs.

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Presentation and release of nodewatcher 3.0

Presentation and release of nodewatcher 3.0 at Battlemesh v8. Nodewatcher is an open source network planning, deployment, monitoring and maintenance platform with emphasis on community. Version 3.0 is a complete rewrite bringing modularity and extensibility.

Meteor Blaze Components

Blaze Components for Meteor are a system for easily developing complex UI elements that need to be reused around your Meteor app. Live tutorial.

My presentation of PeerLibrary at OpenCon 2014

My presentation of PeerLibrary at OpenCon 2014, the student and early career researcher conference on Open Access, Open Education, and Open Data. Slides.

Etage – A general data-flow framework featuring nondeterminism, laziness and neurological pseudo-terminology

Etage is a data-flow based programming language. It is build upon Haskell and provides nondeterminism and laziness. It is text based and through few basic commands it allows defining operations (neurons) and connections between operations (nerves) along which data can flow. Moreover, program can form a network with loops and is not limited to only tree-like structure.

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xml4js – XML to JavaScript parser using XML Schema to guide conversion

XML to JavaScript parser which uses XML Schema to guide conversion. Main motivation is that instead of guessing the structure of an XML document from the document itself, structure is created automatically from the XML Schema which makes output consistent for all XML documents, not just one at hand. For example, arrays are always arrays even when there is only one element in the particular XML document, and if there is only one element allowed, then there will be no one-element array wrapped around. This makes programmatically traversing the structure much easier, because structure is consistent and predictable.

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