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Fault detection method with PCA and LdA and its application to induction motor

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Journal of Central south University 2010年第6期17卷 1238-1242页

作者： JUNG d Y LEE s M 王洪梅 kim J H LEE s H daeho Tech Company Limited department of Electronics Engineering Inha University school of Mechatronics Changwon National University

A feature extraction and fusion algorithm was constructed by combining principal component analysis(PCA) and linear discriminant analysis(LdA) to detect a fault state of the induction *** yielding a feature vector with PCA and LdA from current signal that was measured by an experiment,the reference data were used to produce matching *** a diagnostic step,two matching values that were obtained by PCA and LdA,respectively,were combined by probability model,and a faulted signal was finally *** the proposed diagnosis algorithm brings only merits of PCA and LdA into relief,it shows excellent performance under the noisy *** simulation was executed under various noisy conditions in order to demonstrate the suitability of the proposed algorithm and showed more excellent performance than the case just using conventional PCA or LdA.

关键词： principal component analysis (PCA) linear discriminant analysis (LdA) induction motor fault diagnosis fusionalgorithm

A mild, configurable, flexible CoNi-LdH（v）/Zn battery based on H-vacancy-induced reversible Zn2+ intercalation

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Journal of Energy Chemistry 2025年第1期100卷 498-508页

作者： Xinyue Cheng dingsheng Wu Hao Gao Qingqing Wang Pengfei Lv sam s.Yoon Qufu Wei Key Laboratory of Eco-textiles Ministry of Education Jiangnan University school of Mechanical Engineering Korea University

Flexible Zn-based batteries have attracted increasing research interest as essential components of wearable energy storage ***,the advancement of flexible aqueous Zn-based batteries based on Co-Ni layered double hydroxide （CoNi-LdH） as the cathode material is hampered by their poor cycling stability and the corrosiveness of alkaline ***,CoNi-LdH nanosheets enriched with H vacancies (CoNi-LdH（v）) were constructed on a flexible carbon cloth （CC） substrate via electrochemical deposition and *** Zn-based battery comprising CoNi-LdH（v）@CC as the cathode exhibited highly reversible conversion reactions and stable operation in 3 M ZnsO4electrolyte （pH=4）.The battery delivered an excellent specific capacity (225 mA h g-1,0.26 mA h cm-2),acceptable cycling stability（53.9%,900 cycles）,and high discharging *** abundant H vacancies served as active sites for the reversible intercalation of Zn2+and the extravasation of NO3-generated channels and space for Zn2+transport and storage,together enabling an excellent Zn2+storage ***,a sandwich-structured solid-state CoNi-LdH（v）@CC//Zn@CC battery was fabricated and was found to exhibit a noteworthy electrochemical performance and mechanical *** a proof of concept,the unencapsulated battery powered a digital watch under various deformation conditions and operated stably for 80 ***,the flexible battery displayed outstanding customizability,maintaining an open-circuit voltage of 1.42 V even after being cut *** proposed engineering strategy contributes to the realization of textiles with truly wearable energy-storage devices.

关键词： CoNi/Zn battery H vacancies Mild aqueous electrolyte Tailorable battery Wearable energy storage device

Effect of si Content on Mechanical Properties of a Mo and V Free Low Alloy Cast steel for Automobile Cold Pressing die

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Journal of Materials science & Technology 2008年第3期24卷 313-316页

作者： B.H.kim J.s.shin s.M.Lee B.M.Moon H.d.kim s.Y.Ju O.Y.Choi Advanced Materials R＆d division Korea Institute of Industrial Technology Incheon 406-840 Korea Tooling Center GM Daewoo Auto ＆ Technology Co. Incheon 403-714 Korea

The effects of si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low alloy cast steel for automobile cold pressing die insert. For the evaluation of the applicability as the die insert, the mechanical properties were measured after spheroidization annealing （sA）, quenching and tempering （Q/T）, and flame hardening （FH） treatments, respectively. The developed 0.8%-1.6%si containing Mo and V free alloy cast steels showed excellent matrix strengthening effect, hardenability, and weldability, fulfilling the industrial criterion of the mechanical properties for the die insert.

关键词： Low alloy cast steel Cold pressing die die insert Matrix hardening Flame hardening

Exercise preconditioning alleviates ischemia-induced memory deficits by increasing circulating adiponectin

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Neural Regeneration Research 2025年第5期20卷 1445-1454页

作者： Meifeng Zheng Borui Zhang sonata s Y Yau Kwok-Fai so Li Zhang Haining Ou department of Rehabilitation Medicine Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina department of Rehabilitation Medicine The Fifth Clinical College of Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Key Laboratory of CNs Regeneration(Ministry of Education) Guangdong-Hong Kong-Macao Institute of CNS RegenerationJinan UniversityGuangzhouGuangdong ProvinceChina department of Rehabilitation sciences The Hong Kong Polytechnic UniversityHong Kong Special Administrative RegionChina state Key Laboratory of Brain and Cognitive science Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong Special Administrative RegionChina Center for Exercise and Brain science School of PsychologyShanghai University of SportShanghaiChina Neuroscience and Neurorehabilitation Institute University of Health and Rehabilitation SciencesQingdaoShandong ProvinceChina

Cerebral ischemia is a major health risk that requires preventive approaches in addition to drug *** exercise enhances neurogenesis and synaptogenesis,and has been widely used for functional rehabilitation after *** this study,we determined whether exercise training before disease onset can alleviate the severity of cerebral *** also examined the role of exercise-induced circulating factors in these *** mice were subjected to 14 days of treadmill exercise training before surgery for middle cerebral artery *** found that this exercise pre-conditioning strategy effectively attenuated brain infarct area,inhibited gliogenesis,protected synaptic proteins,and improved novel object and spatial memory *** analysis showed that circulating adiponectin plays a critical role in these preventive effects of *** activation of adiponectin receptors by Adipo Ron mimicked the effects of exercise,while inhibiting receptor activation abolished the exercise *** summary,our results suggest a crucial role of circulating adiponectin in the effects of exercise pre-conditioning in protecting against cerebral ischemia and supporting the health benefits of exercise.

关键词： adiponectin cerebral ischemia exercise pre-conditioning hippocampus memory function middle cerebral artery occlusion prefrontal cortex synaptic proteins treadmill exercise

Anomalously strong scattering of spontaneously Produced Laser Radiation in the First Free-Electron Laser and study of Free-Electron Two-Quantum stark Lasing in an Electric Wiggler with Quantum-Wiggler Electrodynamics

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Chinese Physics Letters 2006年第6期23卷 1422-1425页

作者： s. H. kim department of Physics University of Texas at Arlington PO Box 19059 Arlington Texas 76019 USA

We calculate the scattering cross section of an electron with respect to the spontaneously produced laser radiation in the first free-electron laser （FEL） with quantum-wiggler electrodynamics （QWd）. The cross section is 1016 times the Thomson cross section, confirming the result obtained by a previous analysis of the experimental data. A QWd calculation show that spontaneous emission in an FEL using only an electric wiggler can be very strong while amplification through net stimulated emission is practically negligible.

关键词： CLAssICAL ELECTROdYNAMICs RELATIVIsTIC ELECTRONs THERMOdYNAMICs EXPLANATION EMIssION

Electric-Wiggler-Enhanced Three-Quantum scattering and the Output Power Affected by this scattering in a Free-Electron Laser

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Chinese Physics Letters 2009年第1期26卷 58-61页

作者： s. H. kim 6300 Roundrock Trail #4203 Piano Texas 75023 USA

We derive the cross section of scattering through the three-quantum interaction of an electron with the incident laser field, the emitted photon, and an axial electrostatic field produced by the magnetic wiggler in the magnetic wiggler acting as the sole zeroth-order perturbing classical field in the first free-electron laser （FEL）. In the derivation, we apply quantum-wiggler electrodynamics （QWd）. We find that this scattering predominates the usual two-quantum scattering. The output power of spontaneous free-electron two-quantum stark emission driven by the above electrostatic field attenuated by the three-quantum scattering agrees within a factor of 10 with the measured power in the case of the first FEL.

关键词： field emission molybdenum dioxide enhancement factor

The Effect of Non-equilibrium Condensation on the drag Coefficient in a Transonic Airfoil Flow

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Journal of Thermal science 2012年第6期21卷 518-524页

作者： I.W.kim M.M.A.Alam s.J.Lee Y.d.Kwon s.B.Kwon school of Mechanical Engineering Kyungpook Nat.Uni.1370Sankyuk-dongDaegu 702-701Korea dept.of Advanced & Control Eng.saga Uni.Japan

In this study, a transonic flow past NACA0012 profile at angle of attack α=0^0 whose aspect ratio AR is 1.0 with non-equilibrium condensation is analyzed by numerical analysis using a TVd scheme and is investigated using an intermittent indraft type supersonic wind tunnel. Transonic flows of 0.78-0.90 in free stream Mach number with the variations of the stagnation relative humidity（φ0） are tested. For the same free stream Mach number, the increase in φ0 causes decrease in the drag coefficient of profile which is composed of the drag components of form, viscous and wave. In the case of the same Moo and To, for more than φ0=30%, despite the irreversibility of process in non-equilibrium condensation, the drag by shock wave decreases considerably with the increase of φ0. On the other hand, it shows that the effect of condensation on the drag coefficients of form and viscous is negligible. As an example, the decreasing rate in the drag coefficient of profile caused by the influence of non-equilibrium condensation for the case of M∞=0.9 and φ0 =50% amounts to 34%. Also, it were turned out that the size of supersonic bubble （that is, the maximum height of supersonic zone） and the deviation of pressure coefficient from the value for M=1 decrease with the increase of φ0 for the same M∞.

关键词： Non-equilibrium condensation Transonic Moist air drag coefficient Pressure coefficient

Hetero-deformation promoted strengthening and toughening in BCC rich eutectic and near eutectic high entropy alloys

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Journal of Materials science & Technology 2023年第15期146卷 1-9页

作者： d.H.Chung J.Lee Q.F.He Y.K.kim K.R.Lim H.s.kim Y.Yang Y.s.Na department of special Alloys Extreme Materials Research InstituteKorea Institute of Materials ScienceChangwonThe Republic of Korea department of Mechanical Engineering City University of Hong KongKowloon TongKowloonHong KongChina Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyPohangThe Republic of Korea Center for Heterogenic Metal Additive Manufacturing Pohang University of Science and TechnologyPohangThe Republic of Korea department of Materials science and Engineering City University of Hong KongKowloon TongKowloonHong KongChina

Heterostructured eutectic high-entropy alloys(EHEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture ***,the toughening/strengthening mechanisms of these EHEAs have not been thoroughly *** this study,we developed a series of dual-phase Al_((18–2x))Co_(30)Cr_((11+x))Fe_((11+x))Ni_(3)0(x=-1,0,1)eutectic and neareutectic HEAs containing face-centered cubic(FCC)and body-centered cubic(BCC)*** the high amount of BCC,which is referred to as the brittle phase,newly developed EHEAs exhibited superior fracture ***,we discovered that a fully eutectic HEA exhibited further improvements in both yield stress and fracture toughness,outperforming our off-eutectic and other previously reported *** combining experiments and theoretical models,we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic HEA was derived from the high hetero-deformationinduced(HdI)strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.

关键词： Eutectic high entropy alloy Fracture toughness Heterogeneous structure Hetero deformation induced strengthening Misorientation angle

strip Casting of High Performance structural Alloys

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Journal of Rare Earths 2004年第Z2期22卷 78-84页

作者： s s Park J G Lee Nack J kim Center for Advanced Aerospace Materials Pohang University of Science and TechnologyPohang 790-784Korea Center for Advanced Aerospace MaterialsPohang University of Science and TechnologyPohang 790-784Korea Center for Advanced Aerospace MaterialsPohang University of Science and TechnologyPohang 790-784Korea

There exists a great need for the development of high performance alloys due to increasing demands for energy conservation and environmental protection. Application of strip casting shows a strong potential for the improvement of properties of existing alloys and also for the development of novel alloy systems with superior properties. The present paper reviews our Center's activities in the development of high performance alloys by strip casting. Examples include (1) Al alloys, (2) wrought Mg alloys, and (3) bulk metallic glass (BMG) alloys.

关键词： strip casting 6061 Al alloy AZ Mg alloy bulk metallic glass (BMG) alloy dispersion hardening