One day, your life might depend on being able to tell the difference between a Zeelander 44, a 55 and the 72.

Three different models. Which is which?

At first glace, these boat models are quite similar to each other. You could easily think that a Z44 is a Z55 closer to you.

To figure this out, you can spend 5 hours manually reviewing and annotating a thousands photos, deleting bad training data, and staring at tiny thumbnails photos of these boats until your eyes start bleeding.

Then, put this data into a ResNet34, and see that after all of that effort you are able to tell each model from the others 60% of the time. …


Ownership of this Hyundai Getz cost me 213 €/month, all inclusive.

When I bought my first car I wondered how much it would cost me annually. Now, after 3.5 years of owning a 2005 Hyundai Getz, I can do the maths myself.

Below is the full cost of car ownership for 3.5 years:

Purchase price: 2000 €
Servicing: 1667 €
Fuel (diesel): 2960 €
Highway toll: 440 €
Vehicle inspection and registration: 420 €
Roadside assistance: 120 €
Insurance: 1350 €
Selling price: 900 €

— — — — — — — — —-
Total: 8057 €
Per annum: 2302 €
Per month: 192 €
Per kilometer: 0.155 €

I owned…


As Sentinel Boat Monitor is becoming more and more popular with boat builders and professional installers, the need for a dedicated service and diagnostics app has arisen. We are proud to present the answer to that — meet our brand new Sentinel Tester app.

Use the Sentinel Tester app to install and diagnose Sentinel products that have built-in Bluetooth (BLE). The Sentinel Tester app is at the moment available for Android devices and works with all Boat Monitor devices with Bluetooth support. All units with serial numbers starting with 2116 are supported. …


Sentinel Tester helps you check the installation of your Boat Monitor device without having to activate its subscription plan!

Sentinel’s Boat Monitor is a powerful monitoring solution for boats. It gives real-time position updates and insights into the vital systems (battery, bilge, shore power, …) on your boat. To function it requires an active subscription plan. But sometimes you wish to install the Boat Monitor during winter and activate the subscription only later, when the season starts. To help you properly install your Boat Monitor without activating the subscription plan yet, we are introducing the Sentinel Tester app.

The Tester app is for installers, especially those who are installing many devices at once, for example charter companies or boat…


In Slovenia, a country of just over 2 million inhabitants, there are over 170 active karate clubs. How are these karate clubs distributed over the area of the country? What is their market reach? Let’s find out.

This research builds upon my previous article titled “Analyzing the market size of karate clubs in Slovenia”. In this revision I use data which is more up to date and higher resolution combined with improved methodologies.

If you don’t have time to read this all, scroll to the Results section and enjoy the graphics!

The goal

The goal of the research is to compute a…


In Slovenia, a country of just over 2 million inhabitants, there are over 170 active karate clubs. How are these karate clubs distributed over the area of the country? What is their market reach? Let’s find out.

UPDATE from 27th February 2017: I have published a revision to this study based on more up to date data, higher resolution datasets and a more in-depth analysis. I suggest you read the reviewed version, which you can find here: https://medium.com/@pedro.kostelec/analyzing-the-potential-market-size-of-karate-clubs-in-slovenia-revision-i-95c9a6e12321

The goal

I will begin this analysis by computing a proxy to the potential market for each of the karate clubs. …


Yesterday I realized that emails addressed to my @pedro.si email address were often delayed and sometimes even lost. I have been using my own domain for email for over two years, before I realized that something was wrong. The reason for the lost incoming emails was a CNAME record for my naked domain.

So how did I find out? One of the applications I developed, zatresi.si, sends me an emails whenever some data on the website changes. I send these emails using Mailgun, a service for email tracking. Mailgun also shows when emails are successfully delivered.

Mailgun allows me to monitor email deliveries and tracking.

Last week, as I…


I traveled to China where I visited the cities called Guiyang, Guilin, Xi’an and Beijing.

Guiyang


It’s almost 2 years ago that I started looking for a new dojo to train karate. By then I had been training karate for 4 years and I had trained in three different dojos. While they were all Shotokan style karate dojos, they were at the same time very different. The training techniques, the main goals of the training and even the stances varied from dojo to dojo. …


A retrospective look at our acceleration.

Back in July 2015 we were accepted into the IMPACT accelerator. We had a faint idea of what accelerators do. But it is only now, the day our acceleration ends, that we believe we understand what their value is. And it is not only the monetary grant, the mentoring and the learning. There is something much subtler no one tells you about. It’s what makes the acceleration experience worthwhile for years to come.

Gregor (founder) and Marko (CEO) winning an entry ticket to IMPACT.

In this article I will tell my personal experience of going through the IMPACT accelerator, from September 2015 to April 2016.

Before joining IMPACT my role at…

Pedro Kostelec

Co-founder and CTO of Sentinel Marine Solutions, Artificial Intelligence graduate from Imperial College London

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