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Safety-Constrained Multi-Agent Reinforcement Learning for Power Quality Control in Distributed Renewable Energy Networks

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Computers, Materials & Continua 2024年第4期79卷 449-471页

作者： Yongjiang Zhao Haoyi Zhong chang Cyoon lim Department of Computer Engineering Chonnam National UniversityYeosu59626South Korea

This paper examines the difficulties of managing distributed power systems,notably due to the increasing use of renewable energy sources,and focuses on voltage control challenges exacerbated by their variable nature in modern power *** tackle the unique challenges of voltage control in distributed renewable energy networks,researchers are increasingly turning towards multi-agent reinforcement learning(MARL).However,MARL raises safety concerns due to the unpredictability in agent actions during their exploration *** unpredictability can lead to unsafe control *** mitigate these safety concerns in MARL-based voltage control,our study introduces a novel approach:Safety-ConstrainedMulti-Agent Reinforcement Learning(SC-MARL).This approach incorporates a specialized safety constraint module specifically designed for voltage control within the MARL *** module ensures that the MARL agents carry out voltage control actions *** experiments demonstrate that,in the 33-buses,141-buses,and 322-buses power systems,employing SC-MARL for voltage control resulted in a reduction of the Voltage Out of Control Rate(%***)from0.43,0.24,and 2.95 to 0,0.01,and 0.03,***,the Reactive Power Loss(Q loss)decreased from 0.095,0.547,and 0.017 to 0.062,0.452,and 0.016 in the corresponding systems.

关键词： Power quality control multi-agent reinforcement learning safety-constrained MARL

Abnormal State Detection in Lithium-ion Battery Using Dynamic Frequency Memory and Correlation Attention LSTM Autoencoder

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1757-1781页

作者： Haoyi Zhong Yongjiang Zhao chang Gyoon lim Department of Computer Engineering Chonnam National UniversityYeosu59626South Korea

This paper addresses the challenge of identifying abnormal states in Lithium-ion Battery(LiB)time series *** the energy sector increasingly focuses on integrating distributed energy resources,Virtual Power Plants(VPP)have become a vital new framework for energy *** are key in this context,owing to their high-efficiency energy storage capabilities essential for VPP ***,LiBs are prone to various abnormal states like overcharging,over-discharging,and internal short circuits,which impede power transmission *** methods for detecting such abnormalities in LiB are too broad and lack precision for the dynamic and irregular nature of LiB *** response,we introduce an innovative method:a Long Short-Term Memory(LSTM)autoencoder based on Dynamic Frequency Memory and Correlation Attention(DFMCA-LSTM-AE).This unsupervised,end-to-end approach is specifically designed for dynamically monitoring abnormal states in LiB *** method starts with a Dynamic Frequency Fourier Transform module,which dynamically captures the frequency characteristics of time series data across three scales,incorporating a memory mechanism to reduce overgeneralization of abnormal *** is followed by integrating LSTM into both the encoder and decoder,enabling the model to effectively encode and decode the temporal relationships in the time *** tests on a real-world LiB dataset demonstrate that DFMCA-LSTM-AE outperforms existing models,achieving an average Area Under the Curve(AUC)of 90.73%and an F1 score of 83.83%.These results mark significant improvements over existing models,ranging from 2.4%–45.3%for AUC and 1.6%–28.9%for F1 score,showcasing the model’s enhanced accuracy and reliability in detecting abnormal states in LiB data.

关键词： Lithium-ion battery abnormal state detection autoencoder virtual power plants LSTM

Porocarcinoma in a palm reconstructed with a full thickness skin graft: A case report

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World Journal of Clinical Cases 2024年第3期12卷 665-670页

作者： Seok Beom lim Kun Young Kwon Hoon Kim Soo Yeon lim In chang Koh Department of Plastic and Reconstructive Surgery Konyang University Medical CenterKonyang University of College of MedicineDaejeon 35365South Korea Department of Pathology Konyang University Medical CenterKonyang University of College of MedicineDaejeon 35365South Korea

BACKGROUND Porocarcinoma is a rare type of skin cancer that originates from sweat gland *** is an aggressive malignant skin cancer that is difficult to diagnose clinically owing to its rarity and similarity to squamous cell carcinoma(SCC).CASE SUMMARY This case involved a 92-year-old woman,a farmer by profession,presented with an exophytic and verrucous mass on her left palm that had formed 2 years prior and caused chronic pain and frequent ***,the patient was diagnosed with SCC using a punch biopsy;however,a repeat biopsy with addi-tional immunohistochemical tests was performed for ***,the patient was diagnosed with porocarcinoma and reconstruction was planned using a full-thickness skin *** treatment,the range of motion of the palm was preserved,and the aesthetic outcome was *** 6 mo of follow-up,the patient was satisfied with the *** Porocarcinoma is commonly misdiagnosed as SCC;therefore,clinicians should consider porocarcinomas when evaluating mass-like lesions on the hands.

关键词： Eccrine porocarcinoma Hand defects Reconstructive surgery Sweat gland tumor Skin graft Case report

Immediate secondary rhinoplasty using a folded dermofat graft for resolving complications related to silicone implants: A case report

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World Journal of Clinical Cases 2024年第14期12卷 2426-2430页

作者： Hoon Kim Jong Hyup Kim In chang Koh Soo Yeon lim Department of Plastic and Reconstructive Surgery Konyang University HospitalUniversity of Konyang College of MedicineMyunggok Medical Research InstituteDaejeon 35365South Korea

BACKGROUND Various surgical techniques have been developed to enhance the nose shapes of Asian *** implant augmentation rhinoplasty is widely used because it is relatively easy to perform and often yields satisfactory ***,this technique may lead to complications,including ischemia,necrosis,and *** most appropriate management of these complications,including infection,is immediate implant removal and revision surgery once the accompanying inflammation has ***,the patient may experience distress from nasal deformities during the intervention *** SUMMARY Herein,we describe the case of a patient who underwent a secondary dorsal augmentation,with a folded dermofat graft harvested from the inguinal area and simultaneous implant removal,successfully preventing dimpling of the nasal *** This surgical method can effectively manage implant-related complications following augmentation rhinoplasty using a silicone implant and provide satis-factory patient outcomes.

关键词： Complications Nose deformities Acquired Rhinoplasty Dermofat Surgery Plastic Case report

Protein Arginine Methyltransferase 1 Ablation in Motor Neurons Causes Mitochondrial Dysfunction Leading to Age-related Motor Neuron Degeneration with Muscle Loss

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Research 2024年第1期2023卷 637-649页

作者： Hyun-Kyung So Hyebeen Kim Jinwoo Lee chang-lim You Chae-Eun Yun Hyeon-Ju Jeong Eun-Ju Jin Yunju Jo Dongryeol Ryu Gyu-Un Bae Jong-Sun Kang Department of Molecular Cell Biology Sungkyunkwan University School of MedicineSuwonKorea Single Cell Network Research Center Sungkyunkwan University School of MedicineSuwonKorea Research Institute of Aging-Related Diseases AniMusCureInc.SuwonKorea Drug Information Research Institute Muscle Physiome Research CenterCollege of PharmacySookmyung Women’s UniversitySeoulKorea

Neuromuscular dysfunction is tightly associated with muscle wasting that occurs with age or due to degenerative ***,the molecular mechanisms underlying neuromuscular dysfunction are currently *** studies have proposed important roles of Protein arginine methyltransferase 1(Prmt1)in muscle stem cell function and muscle *** the current study,we set out to determine the role of Prmt1 in neuromuscular function by generating mice with motor neuron-specific ablation of Prmt1(mnKO)using *** exhibited age-related motor neuron degeneration and neuromuscular dysfunction leading to premature muscle loss and ***1 deficiency also impaired motor function recovery and muscle reinnervation after sciatic nerve *** transcriptome analysis of aged mnKO lumbar spinal cords revealed alterations in genes related to inflammation,cell death,oxidative stress,and ***,mnKO lumbar spinal cords of sciatic nerve injury model or aged mice exhibited elevated cellular stress response in motor ***,Prmt1 inhibition in motor neurons elicited mitochondrial *** findings demonstrate that Prmt1 ablation in motor neurons causes agerelated motor neuron degeneration attributing to muscle ***,Prmt1 is a potential target for the prevention or intervention of sarcopenia and neuromuscular dysfunction related to aging.

关键词： degeneration impaired prevention

Clinical validation of scoring systems of postoperative pancreatic fistula after pancreatoduodenectomy: applicability to Eastern cohorts?

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Hepatobiliary Surgery and Nutrition 2019年第3期8卷 211-218页

作者： Jae Seung Kang Taesung Park Youngmin Han Seungyeon Lee Jae Ri Kim Hongbeom Kim Wooil Kwon Sun-Whe Kim Jin Seok Heo Seong Ho Choi Dong Wook Choi Song Cheol Kim Tae Ho Hong Dong sup Yoon Joon Seong Park Sang Jae Park Sung-Sik Han Sae-Byeol Choi Joo Seop Kim chang-sup lim Jin-Young Jang Department of Surgery and Cancer Research Institute Seoul National University College of MedicineSeoulRepublic of Korea Department of Statistics and Interdisciplinary Program in Biostatistics Seoul National UniversitySeoulRepublic of Korea Department of Mathematics and Statistics Sejung UniversitySeoulRepublic of Korea Department of Surgery Samsung Medical CenterSungkyunkwan University School of MedicineSeoulRepublic of Korea Division of Hepatobiliary and Pancreatic Surgery Department of SurgeryUlsan University College of Medicine and Asan Medical CenterSeoulRepublic of Korea Department of Surgery Seoul St.Mary’s HospitalThe Catholic University of KoreaCollege of MedicineSeoulRepublic of Korea Pancreatobiliary Cancer Clinic Department of SurgeryGangnam Severance HospitalYonsei University College of MedicineSeoulRepublic of Korea Center for Liver Cancer National Cancer CenterGyeonggidoRepublic of Korea Department of Surgery Korea University Guro HospitalKorea University College of MedicineSeoulRepublic of Korea Department of Surgery Kangdong Sacred Heart HospitalHallym University College of MedicineSeoulRepublic of Korea Department of Surgery Seoul Metropolitan Government-Seoul National University Boramae Medical CenterSeoul National University College of MedicineSeoulRepublic of Korea

Background:Although several prediction models for the occurrence of postoperative pancreatic fistula(POPF)after pancreatoduodenectomy(PD)exist,all were established using Western ***-scale external validation studies in Eastern cohorts that consider demographic variables including lower body mass index(BMI)are *** purpose of this study was to externally validate POPF prediction models using nationwide large-scale Korean ***:Nine tertiary university hospitals in the Republic of Korea ***'preoperative characteristics,intraoperative factors,and pathologic findings were *** grades were determined according to the 2016 International Study Group on Pancreatic Surgery *** POPF risk models(Callery,Roberts,and Mungroop)were selected for external ***:A total of 1,898 PD patients were enrolled.A non-pancreatic disease diagnosis[hazard ratio(HR),1.856;95%confidence interval(CI),1.223–2.817;P=0.004),higher preoperative BMI(HR,1.069;95%CI,1.019–1.121;P=0.006),and soft pancreatic texture(HR,1.859;95%CI,1.264–2.735;P=0.002)were independent risk factors for clinically relevant POPF(CR-POPF).The area under the receiver operating characteristic curve(AUC)values were 0.61,0.64,and 0.63 on the Callery,Roberts,and Mungroop models,respectively;all were lower than those published in each external validation ***:Western POPF prediction models performed less well when applied to Korean ***,a large-scale Eastern-specific and externally validated POPF prediction model is needed.

关键词： Pancreatic fistula pancreatoduodenectomy(PD) predictive score

Strategies to achieve effective nitrogen activation

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Carbon Energy 2024年第5期6卷 137-163页

作者： Bin chang Huabin Zhang Shuhui Sun Gaixia Zhang KAUST Catalysis Center(KCC) King Abdullah University of Science and Technology(KAUST)ThuwalKingdom of Saudi Arabia Institut National de la Recherche Scientifique(INRS) CentreÉnergie Matériaux TélécommunicationsVarennesQuébecCanada Department of Electrical Engineering École de Technologie Supérieure(ÉTS)MontréalQuébecCanada

Ammonia serves as a crucial chemical raw material and hydrogen energy *** electrocatalytic nitrogen reduction reaction(NRR),powered by renewable energy,has attracted tremendous interest during the past few *** some achievements have been revealed in aqueous NRR,significant challenges have also been *** activity and selectivity are fundamentally limited by nitrogen activation and competitive hydrogen *** review focuses on the hurdles of nitrogen activation and delves into complementary strategies,including materials design and system optimization(reactor,electrolyte,and mediator).Then,it introduces advanced interdisciplinary technologies that have recently emerged for nitrogen activation using high-energy physics such as plasma and *** a better understanding of the corresponding reaction mechanisms in the coming years,these technologies have the potential to be extended in further *** review provides further insight into the reaction mechanisms of selectivity and stability of different reaction *** then recommend a rigorous and detailed protocol for investigating NRR performance and also highlight several potential research directions in this exciting field,coupling with advanced interdisciplinary applications,in situ/operando characterizations,and theoretical calculations.

关键词： activation via mediators catalyst optimization electrochemical nitrogen fixation high-energy activation of nitrogen nitrogen

Real-Time Demand Response Management for Controlling Load Using Deep Reinforcement Learning

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Computers, Materials & Continua 2022年第12期73卷 5671-5686页

作者： Yongjiang Zhao Jae Hung Yoo chang Gyoon lim Department of Computer Engineering Chonnam National UniversityYeosu59626Korea

With the rapid economic growth and improved living standards,electricity has become an indispensable energy source in our ***,the stability of the grid power supply and the conservation of electricity is *** following are some of the problems facing now:1)During the peak power consumption period,it will pose a threat to the power *** and improving the power distribution infrastructure requires high maintenance costs.2)The user’s electricity schedule is unreasonable due to personal behavior,which will cause a waste of *** load as a vital part of incentive demand response(DR)can achieve rapid response and improve demand-side *** load by manually formulating rules,some devices are selective to be adjusted during peak power ***,it is challenging to optimize methods based on manual *** paper uses SoftActor-Critic(SAC)as a control algorithm to optimize the control *** results show that through the coordination of the SAC to control load in CityLearn,realizes the goal of reducing both the peak load demand and the operation costs on the premise of regulating voltage to the safe limit.

关键词： Demand response controlling load SAC CityLearn

GRU-based Buzzer Ensemble for Abnormal Detection in Industrial Control Systems

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Computers, Materials & Continua 2023年第1期74卷 1749-1763页

作者： Hyo-Seok Kim chang-Gyoon lim Sang-Joon Lee Yong-Min Kim Interdisciplinary Program of Information Security Chonnam National UniversityGwangju61186Korea Major in Computer Engineering Chonnam National UniversityYeosu59626Korea School of Business Administration Chonnam National UniversityGwangju61186Korea Department of Electronic Commerce Chonnam National UniversityYeosu59626Korea

Recently,Industrial Control Systems(ICSs)have been changing from a closed environment to an open environment because of the expansion of digital transformation,smart factories,and Industrial Internet of Things(IIoT).Since security accidents that occur in ICSs can cause national confusion and human casualties,research on detecting abnormalities by using normal operation data learning is being actively *** single technique proposed by existing studies does not detect abnormalities well or provide satisfactory *** this paper,we propose a GRU-based Buzzer Ensemble for AbnormalDetection(GBE-AD)model for detecting anomalies in industrial control systems to ensure rapid response and process *** newly proposed ensemble model of the buzzer method resolves False Negatives(FNs)by complementing the limited range that can be detected in a single model because of the internal models composing *** the internal models remain suppressed for False Positives(FPs),GBE-AD provides better *** addition,we generated mean prediction error data in GBE-AD and inferred abnormal processes using soft and hard *** confirmed that the detection model’s Time-series Aware Precision(TaP)suppressed FPs at 97.67%.The final performance was 94.04%in an experiment using anHIL-basedAugmented ICS(HAI)Security Dataset(ver.21.03)among public datasets.

关键词： Industrial control system abnormal detection ensemble learning HAI dataset