I'm Jens Wagemaker, the man that 'gets things done'.
Quotes:
"Sometimes all the puzzle pieces fall in the right place; the result serves as a puzzle piece for the next bigger puzzle."
"If you understand it, it is quite fun!"
Problem solving and creating things are enjoyable and give me the challenge that I need. In work, I like to cooperate with ambitious people. I have a broad interest, but I direct my attention to exact science, ICT and business. Others value me for my kindness and because I can explain things in a clear and patient manner.
At the Vrije Universiteit Amsterdam, I did three bachelor degrees in the studies:
You can reach me at: Jens (dot) Wagemaker (at) gmail (dot) com
Take a look at my projects to see what I'm up to.
I'm Jens Wagemaker, the man that 'gets things done'.
Quotes:
"Sometimes all the puzzle pieces fall in the right place; the result serves as puzzle piece for the next bigger puzzle."
"If you understand it, it is quite fun!"
Problem solving and creating things are enjoyable and give me the challenge that I need. In work, I like to cooperate with ambitious people. I have a broad interest, but I direct my attention to exact science and ICT. Others value me for my kindness and because I can explain things in a clear and patient manner.
At the Vrije Universiteit Amsterdam I did three bachelor degrees in the studies:
You can reach me at: Jens (dot) Wagemaker (at) gmail (dot) com
This thesis was a collaboration between the institutes SRON Netherlands Institute for Space Research and TNO.
In this research the aim is to find and quantify anthropogenic methane hotspots in the Middle-East and China. The atmospheric methane measurements were made with the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument on board the European Space Agency’s environmental research satellite ENVISAT. The SCIAMACHY data showed hotspots and a selection was made. After correcting for elevation it was discovered that one hotspot was actually an elevation related xCH4 anomaly. Because uncertainty in the quantification was expected a calibration was done to the previously studied Four-Corners hotspot. The remaining two hotspots were quantified and showed high emission rates. The Emission Database for Global Atmospheric Research (EDGAR) v4.2 showed no indication of sources of these magnitude and for both of these hotspots the statistical significance has to be further investigated. However a draft version of EDGAR v4.3.2 did show a large emission hotspot coinciding with one of these SCIMACHY hotspots.
This thesis was done at the Vrije Universiteit Amsterdam.
Although having computer checked proves has several advantages, the use of interactive proof assistants has not yet spread into the mathematical community. Problems that withhold mathematicians from using proof assistants include: lack of automation, libraries and expertise. Lean is a new proof assistant, developed towards use by mathematicians. I used Lean to formalize the Mason-Stothers theorem, which is a number theoretical result whose proof is short and yet contains many algebraic concepts. To develop the proof I created a reusable formal library including results on polynomials and unique factorization domains.
This thesis was done at the Vrije Universiteit Amsterdam.
This thesis studies the linear algebra related to the back-propagation algorithm. We wanted to answer the following questions: (1) What is a matrix network? (2) Can a matrix network be represented by a single matrix? (3) To what extent is this representing matrix unique? (4) What happens to the representing matrix when we transpose the network? As a starting point we constructed a paradigm example of a matrix network based on study of the back-propagation algorithm. We found that it was built out of multi functions (a structure we introduced that combines a coproduct, morphism and product). It turned out that there is a canonical relation between multi functions and complete bipartite graphs (of morphisms). This relation allows us to construct representing matrices from complete bipartite graphs and is computationally interesting. To finally answer these questions we use the notion of a graph over a category. We concluded that a matrix network is a graph over the category of matrices. We concluded that a matrix network can be represented by a single matrix by constructing a multi function from the sum over the paths. This representation is far from unique. However, we formulated an equivalence relation that links these different representations. This equivalence relation is used in a hypothesis that describes what happens to the representing matrix when we transpose the network.
A multi function over the category of matrices.
In 2015, I started my tutoring company called Bijles Studio. The company is still in operation.
This company offers tutoring at high school and higher education level, mainly in math and science.For the logo I used my own hand to give it a personal touch. I took a picture and created an SVG image out of that using Inkscape.
I created a 'Terms and Conditions' document ('Algemene Voorwaarden' in Dutch).
For this, I got inspiration from multiple terms and condition documents from other companies.
This is the resulting document (in Dutch):
I build an application that performs the above tasks and more. Due to this application, my administration work is now for 70% automated, moreover, errors are greatly reduced.
This application is web-based. It is made using the technology stack: Ubuntu - Flask (Python server side) - Angular (client side) - MySQL (database).
This is an overview of the components of the application:
For the first version of my system I consulted a friend who had good experience with building web-based applications. I chose to work with the technology stack mentioned before because my friend also used this stack.
A year after building and using the first version of the system, I build a second version. In this second version, I use a MySQL database in the cloud, whereas in the first version, I use a local SQLite database. Moreover, I refactored the application using the book: Flask Web Development, 2nd Edition.