Junhee Hong

Prof. Junhee Hong


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 November 2020 in Journal of Electrical Engineering & Technology
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MNMpho Sam Nkambule
Mpho Sam Nkambule
AHAli Hasan
Ali Hasan
Ahmed Farag AliAhmed Farag Ali
Ahmed Farag Ali
JHJunhee Hong
Junhee Hong
Zong Woo GeemZong Woo Geem
Zong Woo Geem

18 June 2020 in Symmetry
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Journal Article
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AKAnabi Hilary Kelechi
Anabi Hilary Kelechi
MAMohammed H. Alsharif
Mohammed H. Alsharif
OBOkpe Jonah Bameyi
Okpe Jonah Bameyi
PEPaul Joan Ezra
Paul Joan Ezra
IJIorshase Kator Joseph
Iorshase Kator Joseph
JHJunhee Hong
Junhee Hong
Power-consuming entities such as high performance computing (HPC) sites and large data centers are growing with the advance in information technology. In business, HPC is used to enhance the product delivery time, reduce the production cost, and decrease the time it takes to develop a new product. Today’s high level of computing power from supercomputers comes at the expense of consuming large amounts of electric power. It is necessary to consider reducing the energy required by the computing systems and the resources needed to operate these computing systems to minimize the energy utilized by HPC entities. The database could improve system energy efficiency by sampling all the components’ power consumption at regular intervals and the information contained in a database. The information stored in the database will serve as input data for energy-efficiency optimization. More so, device workload information and different usage metrics are stored in the database. There has been strong momentum in the area of artificial intelligence (AI) as a tool for optimizing and processing automation by leveraging on already existing information. This paper discusses ideas for improving energy efficiency for HPC using AI.

8 May 2022 in Energies
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SDSubrat Kumar Dash
Subrat Kumar Dash
SMSivkumar Mishra
Sivkumar Mishra
AAAlmoataz Abdelaziz
Almoataz Abdelaziz
JHJunhee Hong
Junhee Hong
Zong Woo GeemZong Woo Geem
Zong Woo Geem
In a quest to solve the multi-objective optimal planning problem using a simple parameter-free metaheuristic algorithm, this paper establishes the recently proposed student psychology-based optimization (SPBO) algorithm as the most promising one, comparing it with the other two popular nonparametric metaheuristic optimization algorithms, i.e., the symbiotic organisms search (SOS) and Harris hawk optimization (HHO). A novel multi-objective framework (with suitable weights) is proposed with a real power loss minimization index, bus voltage variation minimization index, system voltage stability maximization index, and system annual cost minimization index to cover various technical, economic, and environmental aspects. The performances of these three algorithms are compared extensively for simultaneous allocation of multitype distributed generations (DGs) and D-STACOM in 33-bus and 118-bus test systems considering eight different cases. The detailed analysis also includes the statistical analysis of the results obtained using the three algorithms applied to the two test distribution systems.

22 December 2023 in Sustainability
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Yaren AydınYaren Aydın
Yaren Aydın
CCCelal Cakiroglu
Celal Cakiroglu
Gebrail BekdaşGebrail Bekdaş
Gebrail Bekdaş
Umit IsikdagUmit Isikdag
Umit Isikdag
SKSanghun Kim
Sanghun Kim
Zong Woo GeemZong Woo Geem
Zong Woo Geem
Due to environmental impacts and the need for energy efficiency, the cement industry aims to make more durable and sustainable materials with less energy requirements without compromising mechanical properties based on UN Sustainable Development Goals 9 and 11. Carbon dioxide (CO2) emission into the atmosphere is mostly the result of human-induced activities and causes dangerous environmental impacts by increasing the average temperature of the earth. Since the production of ordinary Portland cement (PC) is a major contributor to CO2 emissions, this study proposes alkali-activated binders as an alternative to reduce the environmental impact of ordinary Portland cement production. The dataset required for the training processes of these algorithms was created using Mendeley as a data-gathering instrument. Some of the most efficient state-of-the-art meta-heuristic optimization algorithms were applied to obtain the optimal neural network architecture with the highest performance. These neural network models were applied in the prediction of carbon emissions. The accuracy of these models was measured using statistical measures such as the mean squared error (MSE) and coefficient of determination (R2). The results show that carbon emissions associated with the production of alkali-activated concrete can be predicted with high accuracy using state-of-the-art machine learning techniques. In this study, in which the binders produced by the alkali activation method were evaluated for their usability as a binder material to replace Portland cement, it is concluded that the most successful hyperparameter optimization algorithm for this study is the genetic algorithm (GA) with accurate mean squared error (MSE = 161.17) and coefficient of determination (R2 = 0.90) values in the datasets.

13 May 2020 in Energies
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VRVipul Rajput
Vipul Rajput
Kartik Shashikant PandyaKartik Shashikant Pandya
Kartik Shashikant Pandya
JHJunhee Hong
Junhee Hong
Zong Woo GeemZong Woo Geem
Zong Woo Geem
This paper introduces a new protection system for solar photovoltaic generator (SPVG)-connected networks. The system is a combination of voltage-restrained overcurrent relays (VROCRs) and directional overcurrent relays (DOCRs). The DOCRs are implemented to sense high fault current on the grid side, and VROCRs are deployed to sense low fault current supplied by the SPVG. Furthermore, a novel challenge for the optimal coordination of DOCRs-DOCRs and DOCRs-VROCRs is formulated. Due to the inclusion of additional constraints of VROCR, the relay coordination problem becomes more complicated. To solve this complex problem, a hybrid Harmony Search Algorithm-Bollinger Bands (HSA-BB) method is proposed. Also, the lower and upper bands in BB are dynamically adjusted with the generation number to assist the HSA in the exploration and exploitation stages. The proposed method is implemented on three different SPVG-connected networks. To exhibit the effectiveness of the proposed method, the obtained results are compared with the genetic algorithm (GA), particle swarm optimization (PSO), cuckoo search algorithm (CSA), HSA and hybrid GA-nonlinear programming (GA-NLP) method. Also, the superiority of the proposed method is evaluated using descriptive and nonparametric statistical tests.

29 September 2020 in Sustainability
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ANTHONY MOHANASUNDARAMANTHONY MOHANASUNDARAM
ANTHONY MOHANASUNDARAM
VPvalsalal prasad
valsalal prasad
KANNADASAN RAJUKANNADASAN RAJU
KANNADASAN RAJU
MAMohammed H. Alsharif
Mohammed H. Alsharif
Zong Woo GeemZong Woo Geem
Zong Woo Geem
JHJunhee Hong
Junhee Hong
This work focuses on the design and analysis of wind flow modifier (WFM) modeling of a vertical axis wind turbine (VAWT) for low wind profile urban areas. A simulation is carried out to examine the performance of an efficient low aspect ratio C-shaped rotor and a proposed involute-type rotor. Further, the WFM model is adapted with a stack of decreased diameter tubes from wind inlet to outlet. It accelerates the wind velocity, and its effectiveness is examined on the involute turbine. Numerical analysis is performed with a realizable K-ε model to monitor the rotor blade performance in the computational fluid dynamics (CFD) ANSYS Fluent software tool. This viscous model with an optimal three-blade rotor with 0.96 m2 rotor swept area is simulated between the turbine rotational speeds ranging from 50 to 250 rpm. The parameters, such as lift–drag coefficient, lift–drag forces, torque, power coefficient, and power at various turbine speeds, are observed. It results in a maximum power coefficient of 0.071 for the drag force rotor and 0.22 for the lift force involute rotor. Moreover, the proposed WFM with an involute rotor extensively improves the maximum power coefficient to an appreciable value of 0.397 at 5 m/s wind speed, and this facilitates efficient design in the low wind profile area.