Educational Background

My story, perhaps, can be told to begin with my tertiary education, which I was undertaking at Institut Teknologi Sepuluh Nopember (ITS) in Surabaya, Indonesia, with a major in structural engineering from 2013 to 2017—gratefully, in a complete four year. It had always been a motivation for me to be majoring in structural engineering from my very first year at the college, and it culminated in my undergraduate thesis on the design of a cable-stayed bridge structure, to which, I am very grateful of having scored a perfect mark. You can visit my undergraduate thesis here.

Work Experience

After earning a Bachelor of Applied Science (B.A.S.) in 2017, I worked at various different positions with different skills required. I was a civil engineer at PT. Wijaya Karya (Persero) Tbk. for a few months, from March 2018 to September 2018. Then I worked as a civil engineering officer at PT. PP (Persero) Tbk. and I was assigned for the bidding team from February 2019 to September 2020. The main task I undertook at this position was preparing civil engineering documents for poject bidding processes, including developing scheduling plans, constuction methodoligical plans and pre-construction engineering assessment for special cases such as analysing and designing the reinforcement for deep excavations, etc.

I started my freelance activity in early 2021 during the pandemic. Most of my freelance works so far were structural engineering designs and evaluations. Some of my past freelance works include structural designs and analyses of a three-storey dormitory building, a three-storey medical storage building, and some three-storey residential houses, and also structural evaluations of a three-storey building renovated into a cafe and industrial warehouses for solar PV installations.

In October 2022, I returned to a full-time position as a civil engineer at PT. PP (Persero) Tbk. for the company's EPC Division. I was assigned for a smelter project located in Kolaka, South East Sulawesi, Indonesia. In this project, I was mainly tasked to guide the consulting vendors for the design and analysis of industrial buildings and infrastructures. Other tasks included developing testing procedures for field testing such as static load tests (SLT) for pile foundations as well as analysing and inferring conclusions from the results, solving specific problems such the structural implications on the functionality change of some buildings due to owner's requests for design alterations or due to the site's challenging conditions. I was also tasked to directly produce the structural reports for several buildings such as chemical store room, and several infrastructures such as pipe bridges and pipe racks. Then, from March 2024 to September 2024, I was assigned for another project on the construction of a port for fuel terminal located in Biak, Papua, Indonesia. In this project, the tasks assigned to me were almost the same with ones in the previous project in Kolaka. In addition, I was highly involved in controlling the material take off (MTO) for the port construction in Biak.

I am currently working as a freelance civil engineer and a part-time research scientist. I am invovled, as a co-researcher, in a research project about an optimization in concreting cycle and carbon emissions of a construction project, led by a Ph.D student at a top university in Indonesia. We are developing a machine learning model (ML) to provide an accurate prediction on the concreting cycle duration and carbon emissions from the project. This model will later serve as an objective function in our optimization problem. My role in this project is being the ML modeller and mathematician; in which, I develop a rigorous mathematical framework for the ML model incorporating probability theory and functional analysis. This project also receives grants from the university.

Research Experience

I began my journey in scientific research in mid 2022, as a consequence of my self-directed exploration in mathematics—which to be narrated as you keep reading this page. My first research project was an interdisciplinary research intersecting mathematics and structural engineering. Inspired by monumental works such as Kolmogorov's in axiomatizing probability and Shanon's in information theory, I had idea of providing a rigorous and formal treatment on pure bending structure incorporating measure theory from mathematics, started with a reinforced concrete beam structure. The central notion in my idea is that we can model the cross section of such a pure bending structure as a measurable space. The stress occuring on the surface of the cross section can then be treated as a measurable function. Eventually, the force on an arbitrary measurable region on the surface of the cross section can be obtained from the Lebesgue integral of the stress measurable function over that region. Likewise, by introducing another measurable function obtained via a pseudometric space on the measurable space, the ultimate moment can be obtained from the Lebesgue integral of the stress measurable function multiplied with the newly introduced measurable function over the entire space. I also proved the conventional nominal moment equation for reinforced concrete beam as a particular implication of my theory. The envisioned importance of this theory is that one can compute the moment capacity of a bending structure with a general well-behaved material and an aribtrary shape.

My second research project was an intersection of mathematics and geotechnical engineering. Specifically, I propose a novel approach for interpreting the result of a static load test (SLT) by incorporating concepts from mathematical analysis, in particular, the concept of Lipschitz continuous function. First, we develeop a differential equation representing the force-settlement relationship from the SLT data. The solution of the differential equation is given by a continuous function $S: \mathbb{R}^+ \to \mathbb{R}^+$. Given some $R > 0$, we can find some connected bounded set $Q_u \subseteq \mathbb{R}^+$ such that $S$ is locally Lipschitz on $Q_u$, i.e., $S \big|_{Q_u}: Q_u \to \mathbb{R}^+$ is Lipschitz. And the critical force of the pile can be given by $$ q_u := \sup{Q_u} \,. $$ This theory, when compared with existing theory, offers a deeper rigor—which is an ideal position for a scientific theory, and objectivity—as it relies on the intrinsic mathematical structure of the SLT result rather than subjective and outright empirical observation on the data.

I also did some other research on more trivial topics—which, in my humble opinion, are not quite high level, such as; estimating the deflection of bending concrete structure using Euler-Bernoulli beam theory based on the approximate moment formulae provided by ACI 318-19, extrapolating Cone Penetration Test (CPT) data by incorporating time series technique with a machine learning implementation, developing a machine learning predictive model for concrete compresive strength, developing my owned customized machine learning-based time series algorithm, and analysing market demand and sales forecast of a coffee shop by incorporating measure and probability theory as the theoretical framework and machine learning as the computational technique. Some of these works may offer some degree of novelty and uniqueness. Therefore, there are still plenty of chances for me to revisit these projects for refinements in the future.

My third original research project was an intersection of mathematics and environmental science. I propose a set of rigorous notions which are very helpful for meticulous analyses on the historical greenhouse gas (GHG) emissions of countries world wide. In this research, borrowing from the formal notions in mathematical analysis and probability theory, I introduced several notions in GHG emissions including; continuous emission process (CEP), discrete emission process (DEP), historical upper bound emission (HUBE), historical peak emission (HPE), rapid growing emission (RGE), rapid shrinking emission (RSE), pivotal periods (Piviods), historical expected growth rate (HEGR) and conditional historical bound space (CHBS). I also demonstrated the use of these notions on a historical GHG emissions dataset, and pinpointing top GHG emitting countries in the world.

My fourth, ongoing, original research is one in mathematical optimization. Having collaborated with a senior mathematician at Institut Teknologi Sepuluh Nopember, we develop a novel optimization algorithm, coined as the Directional Adaptive Metric Sampling Minimal Expected Loss (DAMSMEL). DAMSMEL is a gradient-free optimizer, intended as an alternative to the family of gradient-base optimizers (GBOs). The notable advantage of DAMSMEL over GBOs is that one is not required to compute the gradient of the objective function—effectively reducing the process, and DAMSMEL can escape local minima and eventually converges to the global minimum the right condition whereas GBOs are naturally stuck in local minima. We have empirically tested DAMSMEL on several problems: finding the global minima of a convex objective function, where DAMSMEL matches the GBOs performance; finding the global minima of a nonconvex objective function, where DAMSMEL outperformes GBOs; and implementing DAMSMEL as a machine learning model for predicting the compresive strength of concrete structure, where DAMSMEL matches both linear regression and SGD models. The main drawback of DAMSMEL, however, is the time complexity, which grows very large as the number of sampling, dimension and steps in the hyperparameter are set to be large. It is necessary to assert that DAMSMEL is not a heuristic algorithm, since its construction is grounded in functional analysis and we worked on rigorous properties of DAMSMEL. Notably, I have successfully proven that DAMSMEL reaches the global minimum in convex optimizations. We are still further investigating the functional analysis properties of DAMSMEL such as fixed point property and its potential role as a bounded operator.

Mathematics Journey

Mathematics cannot be separated from my story—it is the most beautiful and elegant abstract creation I’ve ever encountered, and a passion I hold dear. My journey into mathematics began in late 2018, sparked by a self-directed attempt to study the finite element method (FEM). However, I quickly realized that I was missing some essential mathematical foundations that prevented me from fully grasping the subject. This gap led me to explore deeper into mathematics—calculus and differential equations.

That self-directed exploration soon went astray—but in the best way. As the beauty of mathematics unfolded before me, it completely captured my attention, pulling me far beyond my original goal. I eventually reoriented myself: I would pursue mathematics not as a means, but as an end in itself.

I delved into a wide range of mathematical topics—from foundations and abstract pure math to applied mathematics. I spent several months building a strong foundation in set theory and first-order logic. One concept that particularly blew my mind was the hierarchy of infinities: that some infinite sets are strictly larger than others. Another was the famous Russell's paradox, which can be illustrated by the following story:

Imagine a city with a single barber. This barber has a very specific rule: he shaves exactly those men in the city who do not shave themselves. Now, let me ask: Does the barber shave himself?
If the barber shaves himself, then according to his rule, he must not shave himself. But if he does not shave himself, then he must shave himself. This leads to a contradiction: the barber shaves himself if and only if he does not shave himself.

Russell's paradox is just one of several motivations for refining the foundations of set theory. One of the most prominent efforts in this direction is the Zermelo-Fraenkel set theory with the Axiom of Choice (ZFC), within which such paradoxes are avoided by careful axiomatization. Subsequent attempts of refinements followed the framework of axiomatization, generally, known as an axiomatic set theory. Later, I encountered another mind-bending result: Gödel’s Incompleteness Theorems , which reveal fundamental limits of formal systems and mathematics itself.

The most enchanting part of my journey, however, came with my first exposure to group theory and abstract algebra as a whole. For me, abstract algebra, which can simply be described as the study of symmetries, is a pure beauty in mathematics. Furthermore, I delved deeper into pure mathematics and encountered the more abstract sides of mathematics in subjects like measure theory, functional analysis and topology. In particular, topology studies properties of spaces which are invariant under continuous deformation. While functional analysis can be described as a study on abstract vector spaces related to analysis properties such as convergence, completeness and operators between vector spaces.

I have set a direction for myself to further specialize in both topology and functional analysis. I aspire to contribute in these fields, pushing the fields into another frontier, and bringing them back into fruitful real-world applications.