Wednesday, January 29, 2025

Researchers from Incheon National University propose novel approaches for improved microgrid management

A new optimization model improves microgrid operation, enhancing energy efficiency and ensuring reliable power supply

Incheon National University

Optimizing energy use for reliable power supply with sustainable microgrids — image:
A microgrid system powered by renewable energy sources, optimized for efficiency and reliability, offers a stable power supply, ensuring energy security and supporting the transition to sustainable energy solutions
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Credit: "Rural electricity" by kevin dooley Image source Link:https://openverse.org/image/b06e9664-c4b8-429b-8f80-3207c15ba7c5?q=energy+grids&p=10

Microgrids are localized energy systems that provide stable power supply, especially in remote or disaster-prone areas. As the world transitions to renewable energy sources like solar and wind power, microgrids are becoming more essential. However, managing these systems is challenging due to the uncertainties in energy supply and demand, such as power outages or fluctuations in energy usage, and stochastic islanding — situations where parts of the power grid unexpectedly become isolated, disrupting the power supply.

To address these challenges, a team of researchers from Incheon National University, Korea, led by Assistant Professor Jongheon Lee, has developed a new optimization model to improve the operation of microgrids under uncertain conditions. These models not only boost the efficiency and reliability of microgrids but also offer scalable solutions for the real world. Their findings were made available online on August 2, 2024 and was published in Volume 374 of Applied Energy on November 15, 2024.

Traditional methods for optimizing microgrid operations, such as multistage models, are computationally expensive and impractical for real-world use. These models consider different scenarios over time, but the complexity increases exponentially, making their application difficult at a large scale. The researchers have simplified these models while maintaining their effectiveness, by reducing the number of possible scenarios and introducing a process called replanning, where the optimization model adapts over time as new information emerges. This new approach significantly reduced the computational burden, enabling them to be more efficient in real-world settings.

"Our goal was to create a method that makes microgrid operation more adaptable and cost-effective, especially in regions with unreliable grids or frequent disruptions," says Dr. Lee. "By simplifying the models and using replanning, we can achieve effective operation plan without the heavy computational cost."

Microgrids act as essential backup energy source in remote and rural areas where stable grid access is unreliable, ensuring continuous power during outages or natural disasters. With the new models, these microgrids can operate more efficiently, minimizing energy waste and overproduction. Dr. Lee explains, "As renewable energy sources like solar and wind are often unpredictable, balancing these fluctuations is crucial. Our models help manage these uncertainties, ensuring a more stable energy supply.”

Additionally, these solutions are beneficial to cities as well, where the energy demand is rising, and grids are under strain. Scalable optimization models can improve the overall energy management. Adapting to changes in supply and demand in real time helps boost grid resilience, supporting the transition to sustainable energy. Moreover, these models are flexible, making them suitable for both small and large systems.

“These optimization methods will be vital for improving energy security, particularly in areas with unreliable power. They also support global sustainability goals by promoting renewable energy,” highlights Dr. Lee.

In conclusion, this study represents a step forward in creating smarter and more sustainable energy systems, ensuring stable and efficient power for communities around the world.

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Reference

DOI: 10.1016/j.apenergy.2024.124040

Authors: Jongheon Leea, Seulgi Joungb, and Kyungsik Leec

Affiliations:

a Department of Industrial and Management Engineering, Incheon National University, Incheon, Republic of Korea

b Department of Industrial Engineering, Ajou University, Suwon, Republic of Korea

c Department of Industrial Engineering, Seoul National University, Seoul, Republic of Korea

About Incheon National University
Incheon National University (INU) is a comprehensive, student-focused university. It was founded in 1979 and given university status in 1988. One of the largest universities in South Korea, it houses nearly 14,000 students and 500 faculty members. In 2010, INU merged with Incheon City College to expand capacity and open more curricula. With its commitment to academic excellence and an unrelenting devotion to innovative research, INU offers its students real-world internship experiences. INU not only focuses on studying and learning but also strives to provide a supportive environment for students to follow their passion, grow, and, as their slogan says, be INspired.

Website: https://www.inu.ac.kr/sites/inuengl/index.do?epTicket=LOG

About Assistant Professor Jongheon Lee
Dr. Jongheon Lee is an Assistant Professor in the Department of Industrial and Management Engineering at Incheon National University, Republic of Korea. He received his B.S., M.S., and Ph.D. degrees in Industrial Engineering from Seoul National University, South Korea. His research focuses on integer-optimization modeling and algorithms, with applications in production and energy systems. Dr. Lee is dedicated to advancing optimization techniques to improve the efficiency and sustainability of energy systems, particularly in microgrid management.

Journal

Applied Energy

DOI

10.1016/j.apenergy.2024.124040

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Scalable optimization approaches for microgrid operation under stochastic islanding and net load

Forgery and fiscal fraud: a new papyrus from Israel reveals a spectacular criminal case from the Roman empire

The Hebrew University of Jerusalem

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Detail of the infrared image of the Papyrus Cotton
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Credit: (© Israel Antiquities Authority)

Scholars from the Austrian Academy of Sciences, the University of Vienna and the Hebrew University of Jerusalem unveil a unique papyrus from the collections held by the Israel Antiquities Authority, offering rare insights into Roman legal proceedings and life in the Roman Near East. In a new publication in the international scholarly journal Tyche, the research team reveals how the Roman imperial state dealt with financial crimes – specifically, tax fraud involving slaves – in the Roman provinces of Iudaea and Arabia. The new papyrus furnishes a strikingly direct view of Roman jurisdiction and legal practice, as well as important new information about a turbulent era shaken by two massive Jewish revolts against Roman rule.

Link to the photos: https://drive.google.com/drive/folders/1dkaUQW0HLLg7zkxkzMDBVtqcI2lHesAp?usp=sharing

The longest Greek papyrus ever found in the Judaean Desert, comprising over 133 lines of text, has now been published for the first time. Initially misclassified as Nabataean, the papyrus remained unnoticed for decades until its rediscovery in 2014 by Prof. Hannah Cotton Paltiel, emerita of the Hebrew University. "I volunteered to organize documentary papyri in the Israel Antiquities Authority’s scrolls laboratory, and when I saw it, marked ‘Nabataean,’ I exclaimed, ‘It’s Greek to me!’" recalls Prof. Cotton Paltiel. In recognition of her discovery, the papyrus has been named P. Cotton, in line with papyrological conventions.

Recognizing the document’s extraordinary length, complex style, and potential ties to Roman legal proceedings, Prof. Cotton Paltiel assembled an international team to decipher it. The team, including Dr. Anna Dolganov of the Austrian Academy of Sciences, Prof. Fritz Mitthof of the University of Vienna and Dr. Avner Ecker of Hebrew University, determined the document to be prosecutors’ notes for a trial before Roman officials on the eve of the Bar Kokhba revolt (132–136 CE), including a rapidly drafted transcript of the judicial hearing itself. The language is vibrant and direct, with one prosecutor advising another on the strength of various pieces of evidence and strategizing to anticipate objections. "This papyrus is extraordinary because it provides direct insight into trial preparations in this part of the Roman Empire," says Dr. Dolganov. Dr. Ecker adds, "This is the best-documented Roman court case from Iudaea apart from the trial of Jesus."

The papyrus details a gripping case involving forgery, tax evasion, and the fraudulent sale and manumission of slaves in the Roman provinces of Iudaea and Arabia, roughly corresponding to modern Israel and Jordan. The main defendants, Gadalias and Saulos, stand accused of corrupt dealings. Gadalias, the son of a notary and possibly a Roman citizen, had a criminal history involving violence, extortion, counterfeiting, and inciting rebellion. Saulos, his collaborator, orchestrated the fictitious sale and manumission of slaves without paying the requisite Roman taxes. To conceal their activities, the defendants forged documents. "Forgery and tax fraud carried severe penalties under Roman law, including hard labor or even capital punishment," explains Dr. Dolganov.

This criminal case unfolded between two major Jewish uprisings against Roman rule: the Jewish Diaspora revolt (115–117 CE) and the Bar Kokhba revolt (132–136 CE). Notably, the text implicates Gadalias and Saulos in rebellious activities during Emperor Hadrian’s visit to the region (129/130 CE) and names Tineius Rufus, the governor of Iudaea when the Bar Kokhba revolt began. In the wake of prior unrest, Roman authorities likely viewed the defendants with suspicion, connecting their crimes to broader conspiracies against the empire. "Whether they were indeed involved in rebellion remains an open question, but the insinuation speaks to the charged atmosphere of the time," notes Dr. Dolganov. As Dr. Ecker points out, the nature of the crime raises questions, as "freeing slaves does not appear to be a profitable business model." The enslaved individuals’ origins remain unclear, but the case may have involved illicit human trafficking or the Jewish biblical duty to redeem enslaved Jews.

The papyrus offers new insights into Roman law in the Greek-speaking eastern empire, referencing the governor of Iudaea's assize tour and compulsory jury service. "This document shows that core Roman institutions documented in Egypt were also implemented throughout the empire," notes Prof. Mitthof. The papyrus also showcases the Roman state’s ability to regulate private transactions even in remote regions. Likely originating from a hideout cave in the Judaean Desert during the Bar Kokhba revolt, its careful preservation remains a mystery, and the trial's outcome may have been interrupted by the rebellion.

Papyrus Cotton

Credit