Finite-time Secondary Frequency Modulation of Microgrid Based on Event Triggering Mechanism

Chenglong Zhou,Ze Li,Guozeng Cui,Yifan Chen,Wangjun Hao 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.4

This paper designs a ratio consistency algorithm based on event triggering mechanism aiming at the frequency recovery deviation caused by traditional droop control in microgrid. It achieves secondary frequency modulation in microgrid by adjusting the active power setting value. The max-min consistency algorithm is proposed to realize asymptotic consistency of distributed power supply in a finite time. Communication delay is added to ensure the accuracy of frequency update and verifies the robustness of the algorithm against itself. Meanwhile, the validity of event triggering conditions is verified. Finally, the simulation examples are carried out to prove the correctness and superiority of the proposed finite-time control strategy.

Visualizing the distributions and spatiotemporal changes of metabolites in Panax notoginseng by MALDI mass spectrometry imaging

Chenglong Sun,Shuangshuang Ma,Lili Li,Daijie Wang,Wei Liu,Feng Liu,Lanping Guo,Xiao Wang 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.6

Background: Panax notoginseng is a highly valued medicinal herb used widely in China and many Asiancountries. Its root and rhizome have long been used for the treatment of cardiovascular and hematologicaldiseases. Imaging the spatial distributions and dynamics of metabolites in heterogeneous planttissues is significant for characterizing the metabolic networks of Panax notoginseng, and this will alsoprovide a highly informative approach to understand the complex molecular changes in the processing ofPanax notoginseng. Methods: Here, a high-sensitive MALDI-MS imaging method was developed and adopted to visualize thespatial distributions and spatiotemporal changes of metabolites in different botanical parts of Panaxnotoginseng. Results: A wide spectrum of metabolites including notoginsenosides, ginsenosides, amino acids, dencichine,gluconic acid, and low-molecular-weight organic acids were imaged in Panax notoginseng rhizomeand root tissues for the first time. Moreover, the spatiotemporal alterations of metabolites during thesteaming of Panax notoginseng root were also characterized in this study. And, a series of metabolitessuch as dencichine, arginine and glutamine that changed with the steaming of Panax notoginseng weresuccessfully screened out and imaged. Conclusion: These spatially-resolved metabolite data not only enhance our understanding of the Panaxnotoginseng metabolic networks, but also provide dire

Neural Network-based Event-triggered Adaptive Asymptotic Tracking Control for Switched Nonlinear Systems

Chenglong Zhu,Baomin Li,Jianwei Xia,Na Zhang,Rui Liu 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.6

In this paper, an adaptive event-triggered asymptotic tracking control problem is addressed for switched nonlinear systems with unknown control directions. In existing control schemes, the proposed controller is not directly aimed at the original system, which affects the control performance. Different from the existing control schemes, based on the original system, an event-triggered control law is constructed in this paper. The proposed event-triggered controller guarantees that the tracking error ς1 asymptotically converges to the origin. Finally, the effectiveness of the proposed controller design scheme is proved by simulation examples.

Thermal-hydraulic analysis of He-Xe gas mixture in 2×2 rod bundle wrapped with helical wires

Chenglong Wang,Siyuan Chen,Wenxi Tian,G.H. Su,Suizheng Qiu Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.7

Gas-cooled space reactor, which adopts He-Xe gas mixture as working fluid, is a better choice for megawatt power generation. In this paper, thermal-hydraulic characteristics of He-Xe gas mixture in 2×2 rod bundle wrapped with helical wires is numerically investigated. The velocity, pressure and temperature distribution of the coolant are obtained and analyzed. The results show that the existence of helical wires forms the vortexes and changes the velocity and temperature distribution. Hot spots are found at the contact corners between helical wires and fuel rods. The highest temperature of the hot spots reach 1600K, while the mainstream temperature is less than 400K. The helical wire structure increases the friction pressure drop by 20%-50%. The effect extent varies with the pitch and the number of helical wires. The helical wire structure leads to the reduction of Nusselt number. Comparing thermal-hydraulic performance ratios (THPR) of different structures, the THPR values are all less than 1. It means that gas-cooled space reactor adopting helical wires could not strengthen the core heat removal performance. This work provides the thermal-hydraulic design basis for He-Xe gas cooled space nuclear reactor.

Explaining the translation error factors of Korean-Chinese machine translation services using self-attention visualization

Chenglong Zhang,Hyunchul Ahn 한국경영정보학회 2021 한국경영정보학회 학술대회논문집 Vol.2021 No.11

This study analyzed the Korean-Chinese translation error factors of machine translation services such as Papago and Google translate through self-attention path visualization. Self-Attention is a key method of the Transformer and Bert NLP model and recently widely used in machine translation. The study analyzes the difference in the Attention path between ST (source text) and ST' which meaning does not change and the translation output appears more accurately. Understanding these attention path pattern differences and each translation result TT (target text), and TT', the study summarized three types of errors: symbols missing error, grammar error, and multiple meaning words error. The study analyzed using the xlm-ReBerta multilingual NLP model provided by exBERT, for self-attention visualization, and suggesting some suggestions for error resolution. Through the study, it was found that the cause of translation error can be well identified using the Self-Attention visualization method, and through the explanation, machine translation algorithm developers can use it to improve service quality, and researchers can more understand machine translation algorithms.

Spin-orbit interaction and Multiferroicity in Transition Metal Oxides

Chenglong Jia,Shigeki Onoda,Naoto Nagaosa,Jung Hoon Han 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Ampelopsin alleviates sevoflurane-induced cognitive dysfunction by mediating NF-κB pathway in aged rats

Chenglong Liu,Xiaojuan Zha,Haihua Liu,Fang Wei,Fei Zhang 한국유전학회 2020 Genes & Genomics Vol.42 No.4

Background Cancer-induced bone pain (CIBP) is the pain caused by bone metastasis from malignant tumors, and the largest source of pain for cancer patients. miR-300 is an important miRNA in cancer. It has been shown that miR-300 regulates tumorigenesis of various tumors. Purpose This study aims to investigate the role of miR-300 in CIBP and its underlying molecular mechanisms in vitro and in vivo. Methods We constructed CIBP model in rats and investigated the mechanism through which miR-300 affects CIBP. We first examined expression level of miR-300 in CIBP rats and then tested the effect of its overexpression. Next, we identified the target of miR-300 using TargetScan analysis and double luciferase assay. Finally, we studied genetic interactions between miR-300 and its target and their roles in CIBP. Results We found that miR-300 was downregulated in CIBP rats. Overexpression of miR-300 significantly attenuated cancerinduced neuropathic pain (p < 0.01). Furthermore, TargetScan analysis and double luciferase assay show High Mobility Group Box 1 (HMGB1) is a target of miR-300. Notably, HMGB1 is overexpressed in CIBP rats, while up-regulation of miR300 significantly suppresses expression of HMGB1 (p < 0.01). Moreover, knockdown of HMGB1 by siRNA significantly relieves cancer-induced neuropathic pain in rats (p < 0.01). On the other hand, HMGB1 overexpression partially blocked the effect of miR-300 on cancer-induced nerve pain. Conclusion miR-300 relieves cancer-induced neuropathic pain by inhibiting HMGB1 expression. These results may be beneficial for the treatment of CIBP in clinical practice.

miR-300 mitigates cancer-induced bone pain through targeting HMGB1 in rat models

Chenglong Liu,Jianping Yang,Haihua Liu,Tian Xia,Fei Zhang 한국유전학회 2020 Genes & Genomics Vol.42 No.3

Background Cancer-induced bone pain (CIBP) is the pain caused by bone metastasis from malignant tumors, and the largest source of pain for cancer patients. miR-300 is an important miRNA in cancer. It has been shown that miR-300 regulates tumorigenesis of various tumors. Objective This study aims to investigate the role of miR-300 in CIBP and its underlying molecular mechanisms in vitro and in vivo. Methods We constructed CIBP model in rats and investigated the mechanism through which miR-300 affects CIBP. We first examined expression level of miR-300 in CIBP rats and then tested the effect of its overexpression. Next, we identified the target of miR-300 using TargetScan analysis and double luciferase assay. Finally, we studied genetic interactions between miR-300 and its target and their roles in CIBP. Results We found that miR-300 was downregulated in CIBP rats. Overexpression of miR-300 significantly attenuated cancerinduced neuropathic pain (p < 0.01). Furthermore, TargetScan analysis and double luciferase assay show High Mobility Group Box 1 (HMGB1) is a target of miR-300. Notably, HMGB1 is overexpressed in CIBP rats, while up-regulation of miR-300 significantly suppresses expression of HMGB1 (p < 0.01). Moreover, knockdown of HMGB1 by siRNA significantly relieves cancer-induced neuropathic pain in rats (p < 0.01). On the other hand, HMGB1 overexpression partially blocked the effect of miR-300 on cancer-induced nerve pain. Conclusion miR-300 relieves cancer-induced neuropathic pain by inhibiting HMGB1 expression. These results may be beneficial for the treatment of CIBP in clinical practice.

Experimental study on the Influence of Heating Surface Inclination Angle on Heat Transfer and CHF performance for Pool Boiling

Chenglong Wang,Panxiao Li,Dalin Zhang,Wenxi Tian,Suizheng Qiu,G.H. Su,Jian Deng 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1

Pool boiling heat transfer is widely applied in nuclear engineering fields. The influence of heating surface orientation on the pool boiling heat transfer has received extensive attention. In this study, the heating surface with different roughness was adopted to conduct pool boiling experiments at different inclination angles. Based on the boiling curves and bubble images, the effects of inclination angle on the pool boiling heat transfer and critical heat flux were analyzed. When the inclination angle was bigger than 90°, the bubble size increased with the increase of inclination angle. Both the bubble departure frequency and critical heat flux decreased as the inclination angle increased. The existing theoretical models about pool boiling heat transfer and critical heat flux were compared. From the perspective of bubble agitation model and Hot/Dry spot model, the experimental phenomena could be explained reasonably. The enlargement of bubble not only could enhance the agitation of nearby liquid but also would cause the bubble to stay longer on the heating surface. Consequently, the effect of inclination angle on the pool boiling heat transfer was not conspicuous. With the increase of inclination angle, the rewetting of heating surface became much more difficult. It has negative effect on the critical heat flux. This work provides experimental data basis for heat transfer and CHF performance of pool boiling.

Detrital-zircon geochronology and Hf isotope of Paleozoic sedimentary rocks in the Jilin Province, NE China: tectonic significance for microcontinental blocks of eastern Central Asian Orogenic Belt

Chenglong Shi,Xiaozhong Ding,Yanxue Liu,Xiaodong Zhou 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.5

We undertook U-Pb-Hf isotope testing of detrital zircons from Late Paleozoic sedimentary rocks in the Jilin Province, NE China, with the aim of constraining the tectonic evolution of eastern Central Asian Orogenic Belt. The age populations of the detrital zircons from the sandstone of the Jiefangcun Formation in the Songliao Block are ~2234, ~1782, ~1030–921, ~817, ~540, and ~381–254 Ma, whereas those of the zircons from the greywacke of the Permian Kedao Formation in the Songliao Block yield are ~2436, ~1905, ~1692, 1146–1170, ~554–498, and ~342–255 Ma. Combined Hf isotope characteristics, these ages reveal that: (1) rocks from the Jiefangcun and Kedao formations were deposited after 254 and 255 Ma, respectively; (2) these formations were sourced mainly from the Songliao Block and the Jiamus Terrane in the eastern CAOB and to a lesser amount, from the northern margin of the NCC; and (3) it appears that several remnants of ancient Precambrian basement occur adjacent to these Late Paleozoic strata that occur within the microcontinental blocks. Detrital zircons from the silty sandstone of the Miaoling Formation in the western margin of the Khanka Terrane yield peak age populations of 508–476, 463–396, and 348–258 Ma, having similar εHf(t) values to those obtained from zircons within the Jiamusi Terrane. These data indicate that (1) deposition of the Miaoling Formation in the western margin of the Khanka Terrane had started by 258 Ma, and (2) these sediments were sourced mainly from the Jiamusi Terrane and local magmatic rocks. The widespread occurrence of detrital zircons with ages of 480–550 Ma and positive εHf(t) values within the Late Paleozoic strata in the Songliao Block and the Jiamusi–Khanka Terrane, indicates that the amalgamation of these blocks took place during the middle stage of the Paleozoic, probably after the Silurian, prior to the Late Permian.