Bora KAT | Massachusetts Institute of Technology (MIT) (original) (raw)

Papers by Bora KAT

Journal of The Faculty of Engineering and Architecture of Gazi University, Dec 1, 2020

Interactive and dynamic Decision Support System for panelist assignment  Heuristic algorithm tha... more Interactive and dynamic Decision Support System for panelist assignment  Heuristic algorithm that satisfies equity and relevance  Competitive performance on test panels: within 1% of exact solutions Keywords and subject areas of the proposals in the panel Similarity_KW Similarity_SA Proposal Score Panel Score (Initial List) Panel Score (Iterations)

IFIP advances in information and communication technology, 2023

This study is on the service models for dynamic scheduling of multi-class make-to-stock systems. ... more This study is on the service models for dynamic scheduling of multi-class make-to-stock systems. An exponential single-server facility processes different types of items one by one and demand arrivals for different item types occur according to independent Poisson processes. Inventories of the items are managed by base-stock policies and backordering is allowed. The objective is to minimize base-stock investments or average inventory holding costs subject to a constraint on the aggregate fill rate, which is a weighted average of the fill rates of the item types. The base-stock controlled policy that maximizes aggregate fill rate is numerically investigated, for both symmetric and asymmetric systems, and is shown to be optimal for minimizing base-stock investments under an aggregate fill rate constraint. Alternative policies are generated by heuristics in order to approximate the policy that maximizes aggregate fill rate and performances of these policies are compared to those of two...

In the Turkish Electricity Market, electricity trade is carried out largely through Bilateral Agr... more In the Turkish Electricity Market, electricity trade is carried out largely through Bilateral Agreements and the emerging short term imbalances are settled in the Balancing Power Market, particularly the Day Ahead Market. In the Day Ahead Market, the participants submit their bids for each hour of the next day in the form of price-quantity pairs and the Market Operator evaluates those bids using an optimization tool. After the evaluation of the bids, a Market Clearing Price at every hour of the next day and the accepted bids are announced. In this thesis, a mathematical model for balancing a day in the Turkish Electricity Day Ahead Market is proposed. All types of bids, including hourly, block and flexible bids, are included in the model. As the objective function of the model, “total economic welfare”, which is the sum of consumer surplus and producer surplus, is used. In the model, “paradoxically rejected block orders” are also taken into consideration and a bi-criteria solution ap...

Electric Power Systems Research, 2018

In the electricity day-ahead markets (DAMs), market participants place their orders in the form o... more In the electricity day-ahead markets (DAMs), market participants place their orders in the form of desired/ accepted price levels for the submitted quantities. The market operator evaluates these orders and announces the clearing quantities and market clearing prices (MCPs) within an hour. In this paper, a mathematical model is proposed for the exact solution of clearing electricity DAM with a focus on the current Turkish system. The model is a non-linear programming (NLP) problem that maximizes total social welfare and takes into account all types of orders that are submitted in the Turkish DAM. In order to ensure a feasible solution, the concept of paradoxically accepted/rejected orders is introduced. Two versions of the mathematical model are considered, allowing for one type of paradoxical processing in each version. For the computational experiments, a sample data set of 25 days, representing the conditions in the Turkish DAM, is generated and published on an open library. The model is solved to optimality within the practical time limitation of the market operator in all cases. • The COSMOS algorithm [4] used in CWE region includes single

Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi

Makale, bildiri, tez ve proje önerisi gibi akademik metinlerin, gelişen doğal dil işleme araçları... more Makale, bildiri, tez ve proje önerisi gibi akademik metinlerin, gelişen doğal dil işleme araçları ve algoritmaları ile işlenmesi sonucunda elde edilen bilgi farklı amaçlar için kullanılabilmektedir. Mevcut çalışmanın ilk aşamasında, mühendislik alanında kullanılan kelime ve kelime gruplarının içerikleri ve yapıları dikkate alınarak bir kütüphane oluşturulmuş; ilgili metni en uygun ve kapsamlı şekilde tanımlayacak anahtar terimlerin/özniteliklerin çıkarımı gerçekleştirilmiştir. Bu işlem sonucunda elde edilen terim vektörleri kullanılarak farklı dokümanların benzerliğinin tespit edilmesine yönelik bir algoritma geliştirilmiştir. Son olarak ise, gözetimli makine öğrenmesi kapsamında Naïve Bayes sınıflandırıcısı kullanılarak TÜBİTAK Araştırma Destek Programları Başkanlığı’na (ARDEB) sunulan proje önerilerinin 31 farklı mühendislik alt alanından hangisine ait olduğunun tespitine yönelik bir analiz gerçekleştirilmiştir. 1255 proje önerisi ile gerçekleştirilen vaka çalışmasında, önerilen b...

This is to certify that we have read this thesis and that in our opinion it is fully

Date: I hereby declare that all information in this document has been obtained and presented in a... more Date: I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work.

Energy Policy, 2018

MIT Joint Program on the Science and Policy of Global Change combines cutting-edge scientific res... more MIT Joint Program on the Science and Policy of Global Change combines cutting-edge scientific research with independent policy analysis to provide a solid foundation for the public and private decisions needed to mitigate and adapt to unavoidable global environmental changes. Being data-driven, the Joint Program uses extensive Earth system and economic data and models to produce quantitative analysis and predictions of the risks of climate change and the challenges of limiting human influence on the environmentessential knowledge for the international dialogue toward a global response to climate change. To this end, the Joint Program brings together an interdisciplinary group from two established MIT research centers: the Center for Global Change Science (CGCS) and the Center for Energy and Environmental Policy Research (CEEPR). These two centers-along with collaborators from the Marine Biology Laboratory (MBL) at Woods Hole and short-and long-term visitors-provide the united vision needed to solve global challenges.

Annals of Operations Research, 2015

The debate over phasing out fuel subsidies in Indonesia is quite intense. Recent studies pointed ... more The debate over phasing out fuel subsidies in Indonesia is quite intense. Recent studies pointed out an unfair distribution of subsidies. Besides this, the burden of fuel subsidies to Indonesian government is expected to increasingly continue in parallel with rising fuel consumption as well as international oil prices. However, recent experiences indicated that phasing out the fuel subsidy could potentially result in adverse effects in the economy. Then, the need for comprehensive economy-wide analyses in order to reveal diverse impacts of these subsidies, has emerged. The main objective of this study is to estimate the impacts of fuel subsidies from the economic, social, and environmental perspective, and to propose policy options for a subsidy reform. For this purpose, a social accounting matrix model is employed to simulate the impact analysis. Scenarios including reallocation of subsidy to either other sectors (sectoral subsidy) or income groups (target subsidy) are simulated and the social, economic and environmental impacts of these scenarios are presented. The results show that reallocation of fuel subsidy to other sectors will be able to positively increase the overall economic development, while compromising environmental aspects. The direct reallocation of subsidy to the low income households, on the other hand, will slow down overall economic development but show a positive result for social welfare.

... IN SERV˙IS MODELLER˙I Kat, Bora Yüksek Lisans, Endüstri Mühendisli˘gi Bölümü Tez Yöneticisi: ... more ... IN SERV˙IS MODELLER˙I Kat, Bora Yüksek Lisans, Endüstri Mühendisli˘gi Bölümü Tez Yöneticisi: Y. Doc.. ... Life wouldn't be so easy with-out his technical support. Deniz Akhanlı and Ayhun ¨Unal, my housemates, contributed their friendship with sacrifice. ...

Electric Power Systems Research, 2018

In the electricity day-ahead markets (DAMs), market participants place their orders in the form o... more In the electricity day-ahead markets (DAMs), market participants place their orders in the form of desired/accepted price levels for the submitted quantities. The market operator evaluates these orders and announces the clearing quantities and market clearing prices (MCPs) within an hour. In this paper, a mathematical model is proposed for the exact solution of clearing electricity DAM with a focus on the current Turkish system. The model is a non-linear programming (NLP) problem that maximizes total social welfare and takes into account all types of orders that are submitted in the Turkish DAM. In order to ensure a feasible solution, the concept of paradoxically accepted/rejected orders is introduced. Two versions of the mathematical model are considered, allowing for one type of paradoxical processing in each version. For the computational experiments, a sample data set of 25 days, representing the conditions in the Turkish DAM, is generated and published on an open library. The model is solved to optimality within the practical time limitation of the market operator in all cases.

Heavy reliance on imported energy and fossil-intensive energy generation are substantial challeng... more Heavy reliance on imported energy and fossil-intensive energy generation are substantial challenges that contribute to the economic problems that Turkey currently faces. Most of the researchers who assess the economic impacts of energy and environmental policies in Turkey use a general equilibrium approach. The models developed for this purpose thus far including assessing the targets that Turkey has submitted for the Paris Agreement employ an aggregated power sector representation, which does not capture the technological details. Given the importance of power sector to a successful climate policy, we develop an integrated computable general equilibrium (CGE) model of Turkish economy (TR-EDGE) that combines macroeconomic representation of the non-electric sectors and detailed representation of the power sector where disaggregation of Turkish power sector in a CGE framework is the first attempt. We assess the compliance cost of commitments under several scenarios. First, a reference...

Journal of the Faculty of Engineering and Architecture of Gazi University, 2021

Evaluation of project proposals in a proper manner and by the people who have expertise on the to... more Evaluation of project proposals in a proper manner and by the people who have expertise on the topics of the proposals is crucial not only for efficient deployment of resources, but also for credibility of the funding organizations. In this study, an algorithm and a decision support system (PaneLIST) are developed to provide a dynamic list of potential panelists from which the most appropriate set of panelists will be selected. PaneLIST, which is based on MS Excel VBA, has been validated by using the data of TUBITAK, primary organization responsible for research funding and conducts the comprehensive peer review activities for a long time. The results showed that the PaneLIST satisfies the required criteria to a great extent. Moreover, PaneLIST’s performance was compared with the results of the two integer programming models having the objectives of maximizing the sum of relevance scores (EBSkT) and minimizing the total deviation among the evalution levels of the proposals (EKSp) as well as a third model (EBSkT-5) which couples the two. The numerical experiments showed that PaneLIST attains high sum of relevance scores with a balanced distribution in terms of evaluation levels of proposals, thus shows regard to objectives of both EBSkT and EKSp at the same time; moreover, the results are so close (less than 1%) to the results of EBSkT-5 in which sum of relevance scores is maximized under a 5% constraint on the total deviation among the evalution levels of the proposals.

Journal of The Faculty of Engineering and Architecture of Gazi University, Dec 1, 2020

Interactive and dynamic Decision Support System for panelist assignment  Heuristic algorithm tha... more Interactive and dynamic Decision Support System for panelist assignment  Heuristic algorithm that satisfies equity and relevance  Competitive performance on test panels: within 1% of exact solutions Keywords and subject areas of the proposals in the panel Similarity_KW Similarity_SA Proposal Score Panel Score (Initial List) Panel Score (Iterations)

IFIP advances in information and communication technology, 2023

This study is on the service models for dynamic scheduling of multi-class make-to-stock systems. ... more This study is on the service models for dynamic scheduling of multi-class make-to-stock systems. An exponential single-server facility processes different types of items one by one and demand arrivals for different item types occur according to independent Poisson processes. Inventories of the items are managed by base-stock policies and backordering is allowed. The objective is to minimize base-stock investments or average inventory holding costs subject to a constraint on the aggregate fill rate, which is a weighted average of the fill rates of the item types. The base-stock controlled policy that maximizes aggregate fill rate is numerically investigated, for both symmetric and asymmetric systems, and is shown to be optimal for minimizing base-stock investments under an aggregate fill rate constraint. Alternative policies are generated by heuristics in order to approximate the policy that maximizes aggregate fill rate and performances of these policies are compared to those of two...

In the Turkish Electricity Market, electricity trade is carried out largely through Bilateral Agr... more In the Turkish Electricity Market, electricity trade is carried out largely through Bilateral Agreements and the emerging short term imbalances are settled in the Balancing Power Market, particularly the Day Ahead Market. In the Day Ahead Market, the participants submit their bids for each hour of the next day in the form of price-quantity pairs and the Market Operator evaluates those bids using an optimization tool. After the evaluation of the bids, a Market Clearing Price at every hour of the next day and the accepted bids are announced. In this thesis, a mathematical model for balancing a day in the Turkish Electricity Day Ahead Market is proposed. All types of bids, including hourly, block and flexible bids, are included in the model. As the objective function of the model, “total economic welfare”, which is the sum of consumer surplus and producer surplus, is used. In the model, “paradoxically rejected block orders” are also taken into consideration and a bi-criteria solution ap...

Electric Power Systems Research, 2018

In the electricity day-ahead markets (DAMs), market participants place their orders in the form o... more In the electricity day-ahead markets (DAMs), market participants place their orders in the form of desired/ accepted price levels for the submitted quantities. The market operator evaluates these orders and announces the clearing quantities and market clearing prices (MCPs) within an hour. In this paper, a mathematical model is proposed for the exact solution of clearing electricity DAM with a focus on the current Turkish system. The model is a non-linear programming (NLP) problem that maximizes total social welfare and takes into account all types of orders that are submitted in the Turkish DAM. In order to ensure a feasible solution, the concept of paradoxically accepted/rejected orders is introduced. Two versions of the mathematical model are considered, allowing for one type of paradoxical processing in each version. For the computational experiments, a sample data set of 25 days, representing the conditions in the Turkish DAM, is generated and published on an open library. The model is solved to optimality within the practical time limitation of the market operator in all cases. • The COSMOS algorithm [4] used in CWE region includes single

Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi

Makale, bildiri, tez ve proje önerisi gibi akademik metinlerin, gelişen doğal dil işleme araçları... more Makale, bildiri, tez ve proje önerisi gibi akademik metinlerin, gelişen doğal dil işleme araçları ve algoritmaları ile işlenmesi sonucunda elde edilen bilgi farklı amaçlar için kullanılabilmektedir. Mevcut çalışmanın ilk aşamasında, mühendislik alanında kullanılan kelime ve kelime gruplarının içerikleri ve yapıları dikkate alınarak bir kütüphane oluşturulmuş; ilgili metni en uygun ve kapsamlı şekilde tanımlayacak anahtar terimlerin/özniteliklerin çıkarımı gerçekleştirilmiştir. Bu işlem sonucunda elde edilen terim vektörleri kullanılarak farklı dokümanların benzerliğinin tespit edilmesine yönelik bir algoritma geliştirilmiştir. Son olarak ise, gözetimli makine öğrenmesi kapsamında Naïve Bayes sınıflandırıcısı kullanılarak TÜBİTAK Araştırma Destek Programları Başkanlığı’na (ARDEB) sunulan proje önerilerinin 31 farklı mühendislik alt alanından hangisine ait olduğunun tespitine yönelik bir analiz gerçekleştirilmiştir. 1255 proje önerisi ile gerçekleştirilen vaka çalışmasında, önerilen b...

This is to certify that we have read this thesis and that in our opinion it is fully

Date: I hereby declare that all information in this document has been obtained and presented in a... more Date: I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work.

Energy Policy, 2018

MIT Joint Program on the Science and Policy of Global Change combines cutting-edge scientific res... more MIT Joint Program on the Science and Policy of Global Change combines cutting-edge scientific research with independent policy analysis to provide a solid foundation for the public and private decisions needed to mitigate and adapt to unavoidable global environmental changes. Being data-driven, the Joint Program uses extensive Earth system and economic data and models to produce quantitative analysis and predictions of the risks of climate change and the challenges of limiting human influence on the environmentessential knowledge for the international dialogue toward a global response to climate change. To this end, the Joint Program brings together an interdisciplinary group from two established MIT research centers: the Center for Global Change Science (CGCS) and the Center for Energy and Environmental Policy Research (CEEPR). These two centers-along with collaborators from the Marine Biology Laboratory (MBL) at Woods Hole and short-and long-term visitors-provide the united vision needed to solve global challenges.

Annals of Operations Research, 2015

The debate over phasing out fuel subsidies in Indonesia is quite intense. Recent studies pointed ... more The debate over phasing out fuel subsidies in Indonesia is quite intense. Recent studies pointed out an unfair distribution of subsidies. Besides this, the burden of fuel subsidies to Indonesian government is expected to increasingly continue in parallel with rising fuel consumption as well as international oil prices. However, recent experiences indicated that phasing out the fuel subsidy could potentially result in adverse effects in the economy. Then, the need for comprehensive economy-wide analyses in order to reveal diverse impacts of these subsidies, has emerged. The main objective of this study is to estimate the impacts of fuel subsidies from the economic, social, and environmental perspective, and to propose policy options for a subsidy reform. For this purpose, a social accounting matrix model is employed to simulate the impact analysis. Scenarios including reallocation of subsidy to either other sectors (sectoral subsidy) or income groups (target subsidy) are simulated and the social, economic and environmental impacts of these scenarios are presented. The results show that reallocation of fuel subsidy to other sectors will be able to positively increase the overall economic development, while compromising environmental aspects. The direct reallocation of subsidy to the low income households, on the other hand, will slow down overall economic development but show a positive result for social welfare.

... IN SERV˙IS MODELLER˙I Kat, Bora Yüksek Lisans, Endüstri Mühendisli˘gi Bölümü Tez Yöneticisi: ... more ... IN SERV˙IS MODELLER˙I Kat, Bora Yüksek Lisans, Endüstri Mühendisli˘gi Bölümü Tez Yöneticisi: Y. Doc.. ... Life wouldn't be so easy with-out his technical support. Deniz Akhanlı and Ayhun ¨Unal, my housemates, contributed their friendship with sacrifice. ...

Electric Power Systems Research, 2018

In the electricity day-ahead markets (DAMs), market participants place their orders in the form o... more In the electricity day-ahead markets (DAMs), market participants place their orders in the form of desired/accepted price levels for the submitted quantities. The market operator evaluates these orders and announces the clearing quantities and market clearing prices (MCPs) within an hour. In this paper, a mathematical model is proposed for the exact solution of clearing electricity DAM with a focus on the current Turkish system. The model is a non-linear programming (NLP) problem that maximizes total social welfare and takes into account all types of orders that are submitted in the Turkish DAM. In order to ensure a feasible solution, the concept of paradoxically accepted/rejected orders is introduced. Two versions of the mathematical model are considered, allowing for one type of paradoxical processing in each version. For the computational experiments, a sample data set of 25 days, representing the conditions in the Turkish DAM, is generated and published on an open library. The model is solved to optimality within the practical time limitation of the market operator in all cases.

Heavy reliance on imported energy and fossil-intensive energy generation are substantial challeng... more Heavy reliance on imported energy and fossil-intensive energy generation are substantial challenges that contribute to the economic problems that Turkey currently faces. Most of the researchers who assess the economic impacts of energy and environmental policies in Turkey use a general equilibrium approach. The models developed for this purpose thus far including assessing the targets that Turkey has submitted for the Paris Agreement employ an aggregated power sector representation, which does not capture the technological details. Given the importance of power sector to a successful climate policy, we develop an integrated computable general equilibrium (CGE) model of Turkish economy (TR-EDGE) that combines macroeconomic representation of the non-electric sectors and detailed representation of the power sector where disaggregation of Turkish power sector in a CGE framework is the first attempt. We assess the compliance cost of commitments under several scenarios. First, a reference...

Journal of the Faculty of Engineering and Architecture of Gazi University, 2021

Evaluation of project proposals in a proper manner and by the people who have expertise on the to... more Evaluation of project proposals in a proper manner and by the people who have expertise on the topics of the proposals is crucial not only for efficient deployment of resources, but also for credibility of the funding organizations. In this study, an algorithm and a decision support system (PaneLIST) are developed to provide a dynamic list of potential panelists from which the most appropriate set of panelists will be selected. PaneLIST, which is based on MS Excel VBA, has been validated by using the data of TUBITAK, primary organization responsible for research funding and conducts the comprehensive peer review activities for a long time. The results showed that the PaneLIST satisfies the required criteria to a great extent. Moreover, PaneLIST’s performance was compared with the results of the two integer programming models having the objectives of maximizing the sum of relevance scores (EBSkT) and minimizing the total deviation among the evalution levels of the proposals (EKSp) as well as a third model (EBSkT-5) which couples the two. The numerical experiments showed that PaneLIST attains high sum of relevance scores with a balanced distribution in terms of evaluation levels of proposals, thus shows regard to objectives of both EBSkT and EKSp at the same time; moreover, the results are so close (less than 1%) to the results of EBSkT-5 in which sum of relevance scores is maximized under a 5% constraint on the total deviation among the evalution levels of the proposals.