Hi! I’m Harish Narayanan on Harish Narayanan

Gridpaper

Sun, 01 Feb 2026 00:00:00 +0000

Preparing for Mother’s Day

Sat, 18 Mar 2023 00:00:00 +0000

Holi at School

Mon, 13 Mar 2023 00:00:00 +0000

Textually

Sat, 28 Jan 2023 00:00:00 +0000

At Winter Wonderland

Thu, 29 Dec 2022 00:00:00 +0000

Christmas at Kenwood

Mon, 26 Dec 2022 00:00:00 +0000

2022 in review

Sun, 25 Dec 2022 00:00:00 +0000

Christmas time

Sat, 03 Dec 2022 00:00:00 +0000

Women in Saris

Sat, 10 Sep 2022 00:00:00 +0000

Oscar’s fourth birthday

Sun, 04 Sep 2022 00:00:00 +0000

Animals on Bikes

Sat, 03 Sep 2022 00:00:00 +0000

Tense Pokémon battle

Sun, 21 Aug 2022 00:00:00 +0000

Dotty room

Thu, 18 Aug 2022 00:00:00 +0000

At the seaside

Wed, 17 Aug 2022 00:00:00 +0000

Parklife

Tue, 02 Aug 2022 00:00:00 +0000

Over the years

Wed, 01 Jun 2022 00:00:00 +0000

Scancer

Wed, 07 Apr 2021 00:00:00 +0000

HERO Index

Wed, 20 Jan 2021 00:00:00 +0000

Convolutional neural networks for artistic style transfer

Fri, 31 Mar 2017 21:00:00 +0100

There’s an amazing app out right now called Prisma that transforms your photos into works of art using the styles of famous artwork and motifs. The app performs this style transfer with the help of a branch of machine learning called convolutional neural networks. In this article we’re going to take a journey through the world of convolutional neural networks from theory to practice, as we systematically reproduce Prisma’s core visual effect.

Scalable and resilient Django with Kubernetes

Thu, 31 Mar 2016 21:00:00 +0100

If things work out as you’ve envisioned, there will be a time in your webapp’s lifecycle when it’s serving a large number of users. By the time things get to this point, it’s ideal if you’ve architected your webapp to both scale gracefully to meet this load, and also be resilient to arbitrary failures of underlying compute resources.

This article is about how you can use Docker containers and Kubernetes to help your Django webapp achieve these architectural goals. While it meanders a bit through theory and philosophy, it does work up to a concrete example to help solidify concepts.

Periodic table of the finite elements

Sat, 01 Nov 2014 00:00:00 +0000

Hugo

Tue, 21 Oct 2014 00:00:00 +0000

Shpotify, a command-line interface to Spotify

Wed, 01 Jan 2014 00:00:00 +0000

Our media centre machine at home is an aging Mac with only one open port: SSH. Since it was getting annoying to have to walk up to it every time we wanted to control Spotify, I wrote a simple Bash/Apple script that allows us to remotely control the program from other machines around the house.

With it, we can now do things like this:

Playing one of the best songs ever via the command-line.

Find out more and download Shpotify from the official GitHub project page!

Wedding in Madras

Fri, 29 Nov 2013 00:00:00 +0000

Wedding in Oslo

Wed, 21 Aug 2013 00:00:00 +0000

Colourful Madras

Sun, 04 Aug 2013 00:00:00 +0000

Edgefolio

Thu, 25 Apr 2013 00:00:00 +0000

thinkbot

Fri, 15 Mar 2013 00:00:00 +0000

thinkbot has been a labour of love of mine for some years now. Since it’s currently being rebuilt from scratch (as it often seems to be), I am going to leave you with a story instead of pointing you to something you can play with.

The idea for the project began at a simple place: To make a tool that allows people to easily solve differential equations online.

An online tool for solving differential equations.

The motivating utility of this tool was to allow students to simulate simple mechanical systems right in the browser. I wanted them to be excited to learn concepts in mechanics, and teach students practical skills in computational science along the way.

Service Design Jam

Fri, 01 Mar 2013 00:00:00 +0000

Save the date cupcakes

Sat, 02 Feb 2013 00:00:00 +0000

Wilderness Embassy

Mon, 21 Jan 2013 00:00:00 +0000

Wilderness Embassy aimed to be an engaging website to help children learn more about the relationship between humans, animals and our planet. It suggested fun activities for parents and teachers to do with children in nature, and housed a collection of fictional stories featuring cute characters encouraging children to explore and learn about their environment.

Cat-jo at her mailbox.

Inhabitants of the embassy gazing at the stars.

Inhabitants of the embassy enjoying breakfast.

The project was the brainchild of Tiril Bryn, a friend I made at a weekend event where people were offering their skills to make the world a better place. And the illustrations above are by Mia Skåre. This project was my first foray into web development for a non-technical audience, and it was where I first learnt to work with Ruby on Rails.

Arrested development

Sun, 04 Nov 2012 00:00:00 +0000

Mechanics Academy

Mon, 01 Oct 2012 00:00:00 +0000

Google+ Album Fetcher

Wed, 26 Sep 2012 00:00:00 +0000

Anjana and Varun’s wedding

Mon, 27 Aug 2012 00:00:00 +0000

Little red balloon

Sat, 30 Jun 2012 00:00:00 +0000

Modelling the active mechanical response of the heart

Fri, 01 Jun 2012 00:00:00 +0000

Ventricular myocardium serves as the functional tissue of the heart wall. Driven by intracellular calcium waves, the tissue rhythmically contracts to finite strains. Modelling this behaviour is a key step toward modelling the complex, coupled electro-chemo-mechanical behaviour of the heart.

Our chemo-mechanical formulation for describing and studying the active response of the myocardium is posed within the general framework of continuum thermodynamics. Following the recent work of Holzapfel and Ogden (2009), we treat the passive mechanical response of the tissue as non-homogeneous, orthotropic, nonlinear elastic and nearly-incompressible. Our automated computational framework for nonlinear elasticity, CBC.Twist, allows us to easily implement and test this physiologically-relevant constitutive model.

Wisdemy

Sun, 06 May 2012 00:00:00 +0000

Orchids

Sat, 07 Apr 2012 00:00:00 +0000

More little Sophia

Fri, 06 Apr 2012 00:00:00 +0000

Cardiac Modelling Group Wiki

Fri, 07 Oct 2011 00:00:00 +0000

An electrophysiological model for the chondrocyte

Mon, 19 Sep 2011 00:00:00 +0000

Cartilage is the soft tissue that cushions bones at joints and usually allows for bones to slide past each other. Osteoarthritis is a debilitating disorder that’s caused when cartilage starts to wear out, resulting in painful and reduced mobility for sufferers of the condition. There exist no drugs that slow down the progression of the disease.

In this work, we use computer models to better understand the cell responsible for the synthesis of cartilage: the chondrocyte.

In and around Reykjavik

Sat, 03 Sep 2011 00:00:00 +0000

Little Sophia

Sat, 06 Aug 2011 00:00:00 +0000

Dorsal, a simple scientific package management system

Wed, 01 Jun 2011 00:00:00 +0000

A computer algebra system for iOS

Sat, 26 Feb 2011 00:00:00 +0000

One of the first things I did upon getting an iPhone last year was to fork over an additional $99 to Apple Developer Connection, to get access to their iOS development tools and the right to run my own apps on my own phone. This has been exciting because programming for the phone has involved learning a lot: a whole new programming paradigm, touch-based UI design, a new programming language and a host of new APIs. It is in the midst of all this manic learning that I started working in earnest on my first iOS app: an as-yet unnamed computer algebra system.

Point cloud transformation

Sat, 15 Jan 2011 00:00:00 +0000

Sipping Cioccolato Caldos in Venice

Sat, 01 Jan 2011 00:00:00 +0000

Tracking body parameters over time

Sat, 01 Jan 2011 00:00:00 +0000

The FEniCS Project

Tue, 30 Nov 2010 00:00:00 +0000

The source code for the FEniCS Project website can be found in a repository on Bitbucket.

Gallivanting across Scandinavia

Fri, 21 May 2010 00:00:00 +0000

Breakfast on May 17

Mon, 17 May 2010 00:00:00 +0000

Ivan and Romana’s classroom

Mon, 05 Apr 2010 00:00:00 +0000

Portraits

Thu, 25 Feb 2010 00:00:00 +0000

Adaptive multiphase flow through porous media

Sun, 03 Jan 2010 00:00:00 +0000

There are numerous systems in which it is of interest to study the flow of multiple fluids through porous media. Some examples of these include the transport of dissolved nutrients through biological tissue and the extraction of petroleum from underground deposits. In many practical situations, the physics of such flows are characterised by coupled governing equations that are nonlinear and transient, and the problem is further complicated by material heterogeneity and irregular geometries.

Swimming and singing in Smögen

Thu, 13 Aug 2009 00:00:00 +0000

Geetha and Ashwin’s wedding

Sat, 04 Jul 2009 00:00:00 +0000

Automated algorithms for finite strain elasticity

Mon, 01 Jun 2009 00:00:00 +0000

Nonlinear elasticity theory plays a fundamental role in modelling the mechanical response of many polymeric and biological materials. Such materials are capable of undergoing finite deformation, and their material response is often characterised by complex, nonlinear constitutive relationships. Because of these difficulties, predicting the response of such materials to arbitrary loads requires numerical computation (usually based on the finite element method).

The steps involved in the construction of the required finite element algorithms are classical and straightforward in principle, but their application to non-trivial material models are typically tedious and error-prone. We believe our automated computational framework for nonlinear elasticity, CBC.Twist is an elegant solution to this problem.

Molly turns three oh!

Fri, 08 May 2009 00:00:00 +0000

Robust methods for modelling biological flow

Thu, 01 Jan 2009 00:00:00 +0000

Accurate and efficient modelling of biomedical flows is of substantial interest because of its immediate applicability to a variety of fields, including the design of medical devices, the planning of surgical procedures and most fundamentally, the scientific understanding of healthy and diseased biological function. The complexity in this problem arises from the fact that physically-interesting flows occur in complex, patient-specific geometries and often occur in conjunction with other physics such as the finite deformation of the vascular walls and biochemical reaction-diffusion processes.

A summer morning

Sun, 08 Jun 2008 00:00:00 +0000

Phase transfer in battery materials

Sun, 01 Jun 2008 00:00:00 +0000

Lithium-ion batteries are one of the most popular types of rechargeable batteries found in consumer electronics. In such batteries, lithium ions move from the negative electrode to the positive electrode when discharging; and return when being charged. To achieve this, these electrodes are constructed out of an intercalated lithium crystallite (a compound that allows for the reversible inclusion of lithium atoms).

In our research, we are interested in mechanical phenomena that arise in this crystallite due to the addition or removal of lithium atoms. This is especially interesting to study near regions of sharp interfaces between crystallite with and without lithium atoms, as the lack of coherency across the interface can cause the material to strain or even crack.

Some thoughts on the Navier-Stokes equations

Sun, 01 Jun 2008 00:00:00 +0000

The following are some lessons learnt while implementing numerical methods for the Navier-Stokes equations.

A tale of two formulations

It is common in the literature to start with the Laplacian formulation of the Navier-Stokes equations,

\begin{align} \mathrm{div}(v) &= 0 \\ \rho \frac{\partial v}{\partial t} + \rho \left(\mathrm{grad}(v)\right)v &= -\mathrm{grad}(p) + \mu \mathrm{lap}(v), \end{align}

when going about deriving numerical methods to simulate incompressible viscous flow. When considered in this strong form, the above formulation is equivalent to the following divergence formulation arising from continuum mechanics:

Modelling the energetics of growing tumours

Tue, 01 Jan 2008 00:00:00 +0000

Cancer is a collective term for a class of diseases that are a leading cause of death worldwide. The World Health Organization reports that in 2008 alone, 7.6 million deaths (about 13% of all deaths worldwide) were the result of various kinds of cancerous tumours. The development of a tumour is a complex phenomenon whose immediate cause is that some specific cell type has managed to overcome the usual regulatory signals of the cell cycle to grow, proliferate and live beyond its normal, programmed range. These rapidly proliferating, diseased cells proceed to invade surrounding tissue and later spread to other organs in a process called metastasis, which is often fatal.

Tiny happy people

Fri, 01 Jun 2007 00:00:00 +0000

The Computational Physics Group

Mon, 01 Jan 2007 00:00:00 +0000

Finite element methods in general relativity

Fri, 03 Nov 2006 00:00:00 +0000

Variational level sets in shape reconstruction from unorganised data sets

Wed, 21 Dec 2005 00:00:00 +0000

Art

Wed, 22 Dec 2004 00:00:00 +0000

Modelling tissue growth and development

Tue, 01 Jun 2004 00:00:00 +0000

This piece summarises aspects of the work that went into my Ph.D. dissertation. If you’re interested in more details, head on over to my more formal research writing.

Introduction

There is a lot of compelling clinical evidence that suggests the pervasive influence of mechanical factors in biological growth. The central goal of this modelling work is to gain a deeper understanding of the biophysical bases underlying these influences.

The utility of the resulting mathematical and computational framework extends across disciplines by helping steer and interpret experimental work, both under physiological and pathological cases of interest. Our initial focus is directed toward a better understanding of the mechanics of growing soft tissue, specifically tendon.

My personal website

Sun, 22 Jul 2001 00:00:00 +0000

This website has existed in some form or another for over twenty years. It has evolved quite a bit in this period, and the following attempts to catalogue this evolution.

You can find the complete source code for the current version and previous two versions of the site on GitHub. You can also find the styles for Version 2 and Version 3 on GitHub. These were very popular in their day, powering many a similar looking website!