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Machine learning based fault detection and state of health estimation of proton exchange membrane fuel cells

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能源与人工智能(英文) 2023年第2期12卷 178-186页

作者： Vijay Mohan Nagulapati SShiva kumar Vimalesh Annadurai Hankwon Lim School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology50 UNIST-gilEonyang-eupUlju-gunUlsan44919Republic of Korea Carbon Neutrality Demonstration and Research Center Ulsan National Institute of Science and Technology50 UNIST-gilEonyang-eupUlju-gunUlsan44919Republic of Korea Department of Mechatronics Rajalakshmi Engineering CollegeChennaiTamilnaduIndia Graduate School of Carbon Neutrality Ulsan National Institute of Science and Technology50 UNIST-gilEonyang-eupUlju-gunUlsan44919Republic of Korea

In fuel cells, chemical energy is directly converted into heat and electricity without any emissions which makes them an attractive substitute for various energy needs. Fuel cells have high energy conversion ratio and highpower densities which make them suitable for automotive applications. However, these fuel cell systems suffer with low reliability and durability as system components develop faults during operation resulting in degradation and diminished system performance. In this context, fault detection and fault mitigation strategies are being extensively developed. Diagnostic approaches like electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic analysis offer a truthful representation of the State of Health (SOH) of the fuel cell. However, these approaches are intrusive and require pausing the operation of the fuel cell effecting its integrity. Machine learning based fault detection and SOH estimation is a non-intrusive approach where a mapping function is established between the indicators and SOH. The SOH of a fuel cell can be correlated to the patterns in sensor signals or indicators. Indicators that influence SOH are cell voltages, current density distribution, impedance spectra, acoustic emission and magnetic fields. Developing an accurate fault detection and state estimation technique through data driven machine learning approaches will allow corrective measures to avoid irreversible faults and improve the reliability and durability of fuel cells.

关键词： PEM fuel cell Data driven prognostics Fault detection Dynamic load test Gaussian process regression Support vector machine Artificial neural networks

Forest Conflict on the Forest Resources Management between Indigenous People and the Logging Company in Small Island

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Journal of Agricultural Science and Technology(B) 2015年第4期5卷 257-268页

作者： gun Mardiatmoko Thomas Melianus Silaya Jan Willem Hatulesila Forestry Department Faculty of Agriculture University of Pattimura Ambon 97233 Indonesia

Many conflicts are reported in small islands mainly in Eastern region of Indonesia and it is needed to conflict resolution in the forest sector. The research has been conducted on forest conflict in the small island of Yamdena. The aims of the research were：（1） to determine the customary rights of indigenous peoples to the forest area that was claimed as theirs according to the applicable rules and regulations; （2） to study the causes of conflict between indigenous peoples and the logging company; （3） to analyze the policy in the forest resources management on the customary land. This research is qualitative and uses a case study methodology. Data collection methods used include semi-structured interviews, participant observation and focus group discussion （FGD）. The results showed that indigenous peoples whose livelihood is highly dependent on the forest were most threatened because of forest exploitation of their traditional land by the logging company. Handling of the conflict potential in the forest resources management in Yamdena island was approached through use of traditional laws, involving all the relevant parties to the conflict. The forest management either by indigenous peoples or the logging company is no longer focused on the timber harvesting but more on conservation aspects.

关键词： Forest conflict forest concession customary rights social forestry.

Role of T-type Calcium Channels in Generating Hyperexcitatory Behaviors during Emergence from Sevoflurane Anesthesia in Neonatal Rats

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Neuroscience Bulletin 2020年第5期36卷 519-529页

作者： Feng-Yan Shen Byung-gun Lim Wen Wen Yu Zhang Bo Cao Yue-Guang Si Li-Qing Ma Meng Deng Yang In Kim Young-Beom Kim Ying-Wei Wang Department of Anesthesiology Huashan HospitalFudan UniversityShanghai 200040China Department of Anesthesiology and Pain Medicine Korea University Guro HospitalCollege of MedicineKorea UniversitySeoul 08308Korea Department of Anesthesiology Xinhua HospitalSchool of MedicineShanghai Jiaotong UniversityShanghai 200092China Department of Physiology and Neuroscience Research Institute College of MedicineKorea UniversitySeoul 02841Korea Institute of Brain Functional Genomics East China Normal UniversityShanghai 200062China

In the current study,we sought to investigate whether T-type Ca^(2+)channels(TCCs)in the brain are involved in generating post-anesthetic hyperexcitatory behaviors(PAHBs).We found that younger rat pups(postnatal days 9-11)had a higher incidence of PAHBs and higher PAHB scores than older pups(postnatal days16-18)during emergence from sevoflurane *** power spectrum of the theta oscillations(4 Hz-8 Hz)in the prefrontal cortex was significantly enhanced in younger pups when PAHBs occurred,while there were no significant changes in older *** the power of theta oscillations and the level of PAHBs were significantly reduced by the administration of TCC ***,the sensitivity of TCCs in the medial dorsal thalamic nucleus to sevoflurane was found to increase with age by investigating the kinetic properties of TCCs in *** were activated by potentiated GABAergic depolarization with a sub-anesthetic dose of sevoflurane(1%).These data suggest that(1)TCCs in the brain contribute to the generation of PAHBs and the concomitant electroencephalographic changes;(2)the stronger inhibitory effect of sevoflurane contributes to the lack of PAHBs in older rats;and(3)the contribution of TCCs to PAHBs is not mediated by a direct effect of sevoflurane on TCCs.

关键词： Emergence agitation Neonatal rat General anesthesia Sevoflurane T-type calcium channel Theta wave

Sodium-Coordinated Polymeric Phthalocyanines as Stable High-Capacity Organic Anodes for Sodium-Ion Batteries

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Energy & Environmental Materials 2023年第4期6卷 22-30页

作者： Jeongyeon Lee Yoonbin Kim Soyong Park Kang Ho Shin gun Jang Min Jun Hwang Daekyu Kim Kyung-Ah Min Ho Seok Park Byungchan Han Dennis K.P.Ng Lawrence Yoon Suk Lee Department of Applied Biology and Chemical Technology and Research Institute for Smart Energy The Hong Kong Polytechnic UniversityHung HomKowloon Hong Kong SAR China Department of Chemistry The Chinese University of Hong KongShatinNew Territories Hong Kong SAR China Convergence Research Center for Energy and Environmental Sciences Sungkyunkwan UniversitySuwon Korea Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul Korea School of Chemical Engineering Sungkyunkwan UniversitySuwon Korea

Sodium-ion batteries(SIBs)have attracted considerable interest as an alternative to lithium-ion batteries owing to their similar electrochemical performance and superior long-term cycle *** materials are regarded as promising anode materials for constructing SIBs with high capacity and good ***,utilization of organic materials is rather limited by their low energy density and poor stability at high current *** overcome these limitations,we utilized a novel polymeric disodium phthalocyanines(pNaPc)as SIB anodes to provide stable coordination sites for Na ions as well as to enhance the stability at high current *** varying the linker type during a one-pot cyclization and polymerization process,two pNaPc anodes with O-(O-pNaPc)and S-linkers(S-pNaPc)were prepared,and their structural and electrochemical properties were *** O-pNaPc binds Na ions with a lower binding energy compared with S-pNaPc,which leads to more facile Na-ion coordination/dissociation when engaged as SIB *** use of O-pNaPc significantly improves the redox kinetics and cycle stability and allows the fabrication of a full cell against Na_(3)V_(2)(PO_(4))_(2)F_(3)/C cathode,which demonstrates its practical application with high energy density(288 Wh kg^(-1))and high power density(149 W kg^(-1)).

关键词： coordination chemistry organic anode phthalocyanine polymerization sodium ion battery

Coronary Artery Complications after Right Ventricular Outflow Tract Reconstruction Surgery

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Congenital Heart Disease 2022年第3期17卷 281-295页

作者： Hye Won Kwon Mi Kyoung Song Sang Yun Lee Gi Beom Kim Sungkyu Cho Jae gun Kwak Woong-Han Kim Whal Lee Eun Jung Bae Department of Pediatrics Seoul National University HospitalSeoul National University College of MedicineSeoulSouth Korea Department of Thoracic and Cardiovascular Surgery Seoul National University HospitalSeoul National University College of MedicineSeoulSouth Korea Department of Radiology Seoul National University HospitalSeoulSouth Korea

Background:Mechanisms and clinical manifestations of coronary artery complications after right ventricular outflow tract reconstruction surgery are not well ***:Patients who had coronary artery complications after pulmonary valve replacement or the Rastelli procedure at a single tertiary centre were retrospectively ***:Coronary artery complications were identified in 20 patients who underwent right ventricular outflow tract reconstruction *** median age at diagnosis of coronary artery complication was 21 years(interquartile range:13–25 years).Mechanisms of coronary artery complications were compression by adjacent materials in 12 patients,dynamic compression of intramural course of coronary artery in two patients,and intraoperative injury in six *** coronary artery anomalies were identified in 50%(10/20)of *** patients presented with early postoperative haemodynamic *** patients showed late onset symptoms or signs of coronary insufficiency,including chest pain,ventricular dysfunction,or ventricular *** artery stenosis was incidentally found on cardiac computed tomography angiography in two asymptomatic *** patients underwent surgical interventions,and one patient underwent percutaneous coronary intervention for coronary *** patient with recurrent ventricular tachycardia required an implantable *** were two deaths in patients with intraoperative coronary ***:Preoperative coronary evaluation and long-term follow-up for the development of coronary artery complications are required in patients undergoing right ventricular outflow tract reconstruction surgery to prevent ventricular dysfunction,arrhythmias,and death,especially among those with congenital coronary anomalies.

关键词： Congenital heart disease right ventricular outflow tract reconstruction surgery coronary artery disease

Characteristics of Micro Electrochemical Polishing to Improve the Surface Quality of the Stainless Steel Tube

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Journal of Iron and Steel Research International 2012年第S2期19卷 1137-1140页

作者： Seung-gun Choi Sung-Hyun Kim Eun-Sang Lee Seung-Bok Choi Myeong-woo Cho School of Mechanical Engineering Inha University Department of Mechanical Engineering Inha University

Electrochemical polishing is the anodic dissolution process without contact with tools,is a surface treatment method to make a surface planarization using an electrochemical reaction with low applied *** surface quality is mainly affected by the many process *** improve the surface quality,the control of parameters is very *** aim of this study is to investigate the characteristic of electrochemical polishing effect for inner diameter of Stainless Steel *** order to analyze the characteristics of surface quality were measured in terms of temperature, applied current and machining *** investigation can enhance the surface quality of inner diameter Stainless Steel ***,we have verified improved results by using selected optimal conditions.

关键词： Electrochemical polishing surface quality applied current

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冲击地压粘滑失稳的混沌特性

重庆大学学报（自然科学版） 2009年第6期32卷 633-637,662页

作者：黄滚尹光志重庆大学资源及环境科学学院重庆400030 重庆大学西南资源开发及环境灾害控制工程教育部重点实验室重庆400030

为探讨冲击地压发生的非线性特征,在分析断层型或构造型冲击地压粘滑失稳的原因和特点基础上,引入了模拟粘滑失稳的双滑块模型。理论分析表明,双滑块模型在对称情况下,完全相同的2个滑块可以造成空间上不相同的滑块运动,但其动力学行为... 详细信息

为探讨冲击地压发生的非线性特征,在分析断层型或构造型冲击地压粘滑失稳的原因和特点基础上,引入了模拟粘滑失稳的双滑块模型。理论分析表明,双滑块模型在对称情况下,完全相同的2个滑块可以造成空间上不相同的滑块运动,但其动力学行为只表现出周期性的特点;在非对称的情况下,滑块的粘滑失稳表现出复杂的混沌行为。通过适当考虑模型参数物理意义以及对参数值进行选取,该模型可用于解释断层型或构造型冲击地压粘滑失稳机理,描述其动力学行为复杂的非线性混沌特性。

关键词：冲击地压粘滑混沌双滑块模型

Preparation and Application of Ultra Fine Particles

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Journal of Materials Science & Technology 1997年第4期13卷 249-254页

作者： M.Oda K.Setoguchi E.Fuchita and C.Hayashi(UFP Division, Vacuum Metallurgical Co., Ltd., 516 Yokota, Sanbu-cho, Sanbu-gun, Chiba-pref., Japan 289-12) UFP Division Vacuum Metallurgical Co. Ltd. 516 Yokota Sanbu-cho Sanbu-gun Chiba-pref 289-12 Japan

UFPs are formed using gas evaporation methods. In the gas evaporation methods, configuration of UFPs are controlled to form chain-like shape, complex, and isolated UFP. UFP films can be formed through the gas depositi... 详细信息

关键词： Ag Cu

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应用样条函数处理GPS共视数据

测绘信息与工程 2005年第4期30卷 17-19页

作者：李滚中国科学院国家授时中心

为克服Vondrak方法平滑GPS共视比对数据的两端效应和缺值点处的插值问题,应用样条函数平滑和插值方法对NTSC和CRL的GPS共视数据进行了分析研究。结果表明:这种方法可解决Vondrak平滑方法的两端效应现象;与CircularT的数据比较,用样条函... 详细信息

为克服Vondrak方法平滑GPS共视比对数据的两端效应和缺值点处的插值问题,应用样条函数平滑和插值方法对NTSC和CRL的GPS共视数据进行了分析研究。结果表明:这种方法可解决Vondrak平滑方法的两端效应现象;与CircularT的数据比较,用样条函数平滑数据之后,再进行三次样条插值,缺值点的内符合精度有所提高,整体内符合精度也有所提高。

关键词：时间传递 GPS共视样条平滑样条插值