Initial Position Detection of Permanent Magnet Synchronous Machines with Self-Tuning Extended State Observer

Yawei Wu,Yifan Cui,Ronggang Ni,Shuxin Nie,Xinzhen Wu 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The performance of the initial rotor position detection of Permanent Magnet Synchronous Machines (PMSMs) at standstill depends much on the position observer. In this paper, the Extended State Observer (ESO) is compared with the traditional Proportional Integration (PI) observer adopting the rotating high frequency voltage injection algorithm, and the observer parameter design method is derived based on the bandwidth analysis of the close-loop transfer function. Experiments are carried out on a 3 kW PMSM prototype for verifications.

Experimental Studies on Shear Behavior of Sand-Suction Caisson Wall Interface under Variable Normal Load and Penetration Rate

Yifan Li,Dayong Li,Yuqi Wu,Yukun Zhang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.7

Shear characteristics of the interface between sand and the suction caisson wall play animportant role in determining the friction resistance along the suction caisson wall. In thisstudy, a variable normal load (VNL) reflecting the effects of the penetration depth andinstallation rate of a suction caisson is applied using the torsional interface shear apparatus toexamine the interface shear behavior. Results show that the interface friction coefficientdecreases with the increase of the normal stress and shearing rate until reaching a criticalvalue. When the friction coefficient reaches the critical value, the friction coefficient changeslittle with the increase of normal stress. The variation of the friction coefficient caused by theseepage flow and penetration rate should be considered for calculating the frictional forcealong the caisson wall. Given the same shearing rate, the normalized efficiency parameter ofthe interface under the VNL is higher than that obtained under the CNL. The suctioncalculated based on the test results of this study is in good agreement with that from the Tenbyproject, indicating that our findings are reliable and beneficial to analyze the installationprocess of the suction caisson.

A Rendezvous Node Selection and Routing Algorithm for Mobile Wireless Sensor Network

( Yifan Hu ),( Yi Zheng ),( Xiaoming Wu ),( Hailin Liu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.10

Efficient rendezvous node selection and routing algorithm (RNSRA) for wireless sensor networks with mobile sink that visits rendezvous node to gather data from sensor nodes is proposed. In order to plan an optimal moving tour for mobile sink and avoid energy hole problem, we develop the RNSRA to find optimal rendezvous nodes (RN) for the mobile sink to visit. The RNSRA can select the set of RNs to act as store points for the mobile sink, and search for the optimal multi-hop path between source nodes and rendezvous node, so that the rendezvous node could gather information from sensor nodes periodically. Fitness function with several factors is calculated to find suitable RNs from sensor nodes, and the artificial bee colony optimization algorithm (ABC) is used to optimize the selection of optimal multi-hop path, in order to forward data to the nearest RN. Therefore the energy consumption of sensor nodes is minimized and balanced. Our method is validated by extensive simulations and illustrates the novel capability for maintaining the network robustness against sink moving problem, the results show that the RNSRA could reduce energy consumption by 6% and increase network lifetime by 5% as comparing with several existing algorithms.

Inhalation of panaxadiol alleviates lung infl ammation via inhibiting TNFA/ TNFAR and IL7/IL7R signaling between macrophages and epithelial cells

Yifan Wang,Hao Wei,Zhen Song,Liqun Jiang,Mi Zhang,Xiao Lu,Wei Li,Yuqing Zhao,Lei Wu,Shuxian Li,Huijuan Shen,Qiang Shu,Yicheng Xie 고려인삼학회 2024 Journal of Ginseng Research Vol.48 No.1

Background: Lung inflammation occurs in many lung diseases, but has limited effective therapeutics. Ginseng andits derivatives have anti-inflammatory effects, but their unstable physicochemical and metabolic propertieshinder their application in the treatment. Panaxadiol (PD) is a stable saponin among ginsenosides. Inhalationadministration may solve these issues, and the specific mechanism of action needs to be studied. Methods: A mouse model of lung inflammation induced by lipopolysaccharide (LPS), an in vitro macrophageinflammation model, and a coculture model of epithelial cells and macrophages were used to study the effectsand mechanisms of inhalation delivery of PD. Pathology and molecular assessments were used to evaluate efficacy. Transcriptome sequencing was used to screen the mechanism and target. Finally, the efficacy andmechanism were verified in a human BALF cell model. Results: Inhaled PD reduced LPS-induced lung inflammation in mice in a dose-dependent manner, includinginflammatory cell infiltration, lung tissue pathology, and inflammatory factor expression. Meanwhile, the dose ofinhalation was much lower than that of intragastric administration under the same therapeutic effect, which maybe related to its higher bioavailability and superior pharmacokinetic parameters. Using transcriptome analysisand verification by a coculture model of macrophage and epithelial cells, we found that PD may act by inhibitingTNFA/TNFAR and IL7/IL7R signaling to reduce macrophage inflammatory factor-induced epithelial apoptosisand promote proliferation. Conclusion: PD inhalation alleviates lung inflammation and pathology by inhibiting TNFA/TNFAR and IL7/IL7Rsignaling between macrophages and epithelial cells. PD may be a novel drug for the clinical treatment of lunginflammation.

Deposition path-dependent lightweight support design and its implication to self-support topology optimization

Wang Yifan,Wu Tao,Liu Jikai,Yu Huangchao 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.6

This paper presents a lightweight support design method for material extrusion-type three-dimensional printed panel structures that innovatively involves the deposition path curvature information for support point determination. Specifically, this support design method provides a robust segmentation algorithm to divide the filament deposition paths into segments based on the curvature sign alternating condition, and then searches for the fewest support points for the filaments counting on the experimentally calibrated relationship between the maximum allowable self-support distance and the local mean curvature. The proposed method features in generating thin-walled skeleton-ray styled support structures that are lightweight while providing firm support for the panels. More importantly, the support design method provides a new type of self-support criterion for structural topology optimization involving non-designable planar panels, i.e., only a sparse point set would be sufficient to support the panel. Consequently, more materials could be spent on enhancing the load-bearing capacity instead of being wasted on oversupporting. The achievable structural performances from self-support topology optimization with this new self-support criterion can improve significantly. Support design and printing tests were conducted on a few panel structures that validated the improved support effect compared with equal-volume supports generated by commercial software. Equidistant and gap-free deposited filaments, no filament collapse due to insufficient support, and no isolated voids reflect the improved support effect. The improved self-support topological design was also validated through a comparative numerical case study, and a compliance reduction of 7.76% was achieved.

A new kind of rhodamine-based fluorescence turn-on probe for monitoring ATP in mitochondria

Liu, Yifan,Lee, Dayoung,Wu, Di,Swamy, K.M.K.,Yoon, Juyoung Elsevier 2018 Sensors and actuators. B Chemical Vol.265 No.-

<P><B>Abstract</B></P> <P>We have developed a new kind of colorimetric and fluorescence “turn-on” probe based on rhodamine derivatives for the detection of adenosine-5′-triphosphate (ATP) through hydrogen bond interactions. Upon the addition of 5 mM ATP, the probe 1 shows a 65-fold enhancement in fluorescence intensity and a color change from colorless to pink. The probe 2 also shows very obvious color and fluorescence change with the presence of ATP. The experimental results show that this kind of probe has high specificity towards ATP over other anions, metal ions, and other nucleoside polyphosphates, except ADP. The enhanced emission and naked eye changes are attributed to spirolactam ring-opening, which is pH independent (pH (4.0–7.4)). The more important finding from our results is that the electron withdrawing group in the chain decreases the binding ability to ATP. The live cell imaging experiments in Hela cells indicated that probe <B>2</B> has cell permeability, and mainly locates to mitochondria.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three new rhodamine derivatives bearing thiourea group are synthesized and reported as chemosensors for ATP. </LI> <LI> Probe <B>1, 2</B> and <B>3</B> showed distinct colorimetric and fluorescence changes with ATP. </LI> <LI> Probe <B>2</B> was successfully applied to monitor ATP in mitochondria. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Developing syngas fermentation of Clostridium carboxidivorans P7 from laboratory research into manufacture

Guanxun WU,Bintao XIE,Yaqiong GUO,Yifan HAN,Zhiyong HUANG 한국생물공학회 2016 한국생물공학회 학술대회 Vol.2016 No.10

교권 보호 정책의 변동 분석 : Kingdon의 정책흐름모형을 중심으로

이선희,신윤정,Wu, Yifan,정제영 한국교육행정학회 2022 한국교육행정학회 학술연구발표회논문집 Vol.2022 No.12

Overcome energy loss of exciplex-sensitized fluorescence OLEDs with separating exciton generation and fluorescence emission zone

Ning ShuYa,Wu Yuan,Wu ChuanMing,Zhang YiFan,Luo MeiTing,Wang XinYe,Wang DongDong 한국물리학회 2022 Current Applied Physics Vol.39 No.-

TADF-sensitizing-fluorescence (TSF) strategy suffered a disturbing energy loss causing by the T1 states of fluorescence dopant (FD) due to its low T1-state energy and forbidden of radiative transition. In this manuscript, we used TCTA/PO-T2T planar heterojunction (PHJ) interface as exciton generation zone and adjacent PO-T2T layer doped with rubrene as fluorescence emission zone, achieved the maximum EQE and CE of 8.3% and 26.1 cd A-1, respectively for rubrene-based device. Our experiments show the necessary PO-T2T thickness doped with rubrene is 15 nm and thicker doping layer over 15 nm would destroy device efficiency. It was further found that the exciplex exciton begin to decay within the time of 4 nm diffusion distance in PO-T2T layer and most of exciplex excitons were restrained in TCTA/PO-T2T heterojunction interface in PHJ device. The about 1.1 eV barrier for hole injection from TCTA to PO-T2T and bad hole-transporting capability of PO-T2T made exciple exciton only generate on this interface. Thus, even if the rubrene doped PO-T2T layer is right after the TCTA layer, FD in PO-T2T layer are well separated to the exciplex excitons in TCTA/PO-T2T interface, overcoming T1 energy loss caused by FD. Our approach provides a beneficial path towards overcome energy loss causing by the T1 states of FD in TSF-OLEDs based on exciplex as TADF sensitizer.

Preparation and performance of non-sintered lightweight aggregates derived from textile sludge and coal fly ash

Yueqing Xu,Xinyu Wu,Houhu Zhang,Qingya Zhang,Yifan Xu 대한환경공학회 2023 Environmental Engineering Research Vol.29 No.3

The feasibility of preparing non-sintered lightweight aggregate using textile sludge and coal fly ash as the main raw materials was investigated. Extensive experiments were conducted to analyze the effects of different coal fly ash/sludge ratio, sodium silicate addition and curing time on the performance of non-sintered lightweight aggregates (NSLWAs). The optimal preparation parameters were determined as follows: coal fly ash/cement ratio of 2.2, textile sludge addition of 20%, sodium silicate addition of 10%, and curing time of 28 days. Under these optimal preparation conditions, the cylindrical compressive strength of NSLWAs was relatively high. The test results of Zn leaching toxicity test and S content all met the relevant standards and environmental safety requirements. NSLWA has a dense internal structure with uniformly distributed grains. By analyzing the hydration reaction mechanism during the NSLWAs preparation, it can be obtained that part of Zn<SUP>2+</SUP> was stabilized by conversion into insoluble Ca(Zn(OH)₃)₂・2H₂O, while the remaining part was solidified and stabilized through encapsulation and adsorption of hydration products. Furthermore, it was discovered that pozzolanic admixtures played a crucial role in the hydration and hardening process of NSLWAs, and the presence of C-S-H gel and Mullite contributed to the increase in cylinder compressive strength of NSLWAs.