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Wall shear-stress extraction by an optical flow algorithm with a sub-grid formulation

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Acta Mechanica Sinica 2021年第1期37卷 65-79,I0003页

作者： The hung Tran Lin chen Faculty of Aerospace Engineering Le Quy Don Technical UniversityHanoi10000Vietnam Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing100049China

In this study,we developed a novel optical-flow algorithm for determining the wall shear-stress on the surface of *** algorithm solves the thin-oil-film equation using a numerical scheme that recovers local features neglected by smoothing filters.A variational formulation with a smoothness constraint was applied to extract the global shear-stress *** algorithm was then applied to scalar images generated using direct numerical simulation(DNS)method,which revealed that the errors were smaller than those of conventional *** application of the proposed algorithm to recover the wall shear-stress on a low-aspect-ratio wing and on an axisymmetric boattail model taken as examples in this study showed a strong potential for analysing shear-stress *** to the methods used in previous studies,proposed method reveals more local features of separation line and singular points on object surface.

关键词： Wall shear-stress Optical flow Thin-oil-film equation Sub-grid model

Skew Derivations with Power Central Values on Commutators

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Algebra Colloquium 2015年第3期22卷 479-494页

作者： hung-Yuan chen Department of Mathematics National Changhua University of Education Changhua City 500 Taiwan

Let R be a prime ring with center Z, 5 ： R → R a nonzero skew derivation, and n a fixed positive integer. In this paper, we show that R is a commutative ring if （i） [（δ（[x, y]）, [x, y]]n = 0 for all x, y ∈ R ... 详细信息

关键词： automorphism prime ring Martindale quotient ring skew derivation Minner

Between Darwin and Hegel： On Dewey＇s Concept of Experience

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Frontiers of Philosophy in China 2017年第1期12卷 104-119页

作者： chen Yaj un School of Philosophy Fudan University Shanghai 200433 China

＂Experience＂ is so central to Dewey＇s philosophy that one mu^t, first of all, understand what he means by the term. Diverging from the traditional conception of experience, Dewey＇s understanding involves two dimensions, namely, naturalism and historicism; in this, it can be seen as the unification of Darwinism and Hegelianism. Without attending to its dimension of naturalism, one would ignore experience＇s basic character, namely that of receptivity, while without attending to the aspect of historicism, one would ignore experience＇s dimension of meaning, its character of spontaneity. Dewey＇s notion of experience is unique. Its true value can be seen more clearly in comparison with the conceptions of experience advanced by Quine and McDowell.

关键词： experience interaction meaning naturalism historicism

Numerical characteristics of the full operator hybrid simulation method

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Earthquake Engineering and Engineering Vibration 2011年第3期10卷 453-463页

作者： Chung-Chan hung Yong-Song chen Department of Civil Engineering Central University （NCU） Chinese Taipei Department of Mechanical Engineering Chung Cheng University （NCCU） Chinese Taipei

The full operator method （FOM） has been proposed to overcome some of the shortcomings of the commonly used operator splitting method （OSM）. In particular, the FOM is improved by increasing the accuracy of both the predictor and corrector using the estimated tangent stiffness of the tested structure. The numerical characteristics of the FOM, including stability and accuracy, are investigated in this study. It is shown that FOM is conditionally stable. The stability and accuracy characteristics are dependent on the accuracy of the estimated tangent stiffness and the parameters associated with the acceleration variation in the time-stepping integration method. Mass-spring systems with different types of nonlinearity, including hardening, stiffening, and softening behavior, are used to evaluate the performance of the FOM. It is found that the FOM can capture these types of nonlinearity with satisfactory accuracy. Using a prototype 12-story composite coupled wall system, the influences of the strong nonlinearity of the system as well as the displacement control errors from hydraulic actuators on the performance of the FOM are explored. The results show that the FOM is capable of generating reasonably accurate results despite the presence of strong structural nonlinearity and displacement control errors.

关键词： hybrid simulation tangent stiffness numerical characteristic composite coupled wall system collapse behavior nonlinear behavior

Realization of energy-saving glass using photonic crystals

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Frontiers in Energy 2018年第1期12卷 178-184页

作者： Yen-Hsiang chen Li-hung LIAO Yu-Bin chen Department of Mechanical Engineering Cheng Kung University Tainan701 Taiwan China Department of Power Mechanical Engineering TsingHua UniversityHsinchu 300 Taiwan China

This work successfully developed an energy- saving glass with wavelength selectivity. The glass is composed of a SiO2 substrate and two layers of three- dimensional photonic crystals. Each crystal is composed of identical and transparent polystyrene spheres after their self-assembling. The glass then possesses dual photonic band gaps in the near-infrared region to suppress penetration of thermal radiation. Experimental results show that the energy-saving glass decreases temperature increment in a mini-house. Moreover, the temperature after thermal equilibrium is lower than that inside a counterpart using ordinary glass.

关键词： energy-saving glass photonic crystals poly-styrene spheres self-assembly

Intelligent Mobile Video Surveillance System with Multilevel Distillation

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Journal of Electronic Science and Technology 2017年第2期15卷 133-140页

作者： Yuan-Kai Wang hung-Yu chen Department of Electrical Engineering Fu Jen Catholic UniversityNew Taipei City 24205 Intelligent System Lab.Fu Jen Catholic university New Taipei City 24205

This paper proposes a mobile video surveillance system consisting of intelligent video analysis and mobile communication networking. This multilevel distillation approach helps mobile users monitor tremendous surveillance videos on demand through video streaming over mobile communication networks. The intelligent video analysis includes moving object detection/tracking and key frame selection which can browse useful video clips. The communication networking services, comprising video transcoding, multimedia messaging, and mobile video streaming, transmit surveillance information into mobile appliances. Moving object detection is achieved by background subtraction and particle filter tracking. Key frame selection, which aims to deliver an alarm to a mobile client using multimedia messaging service accompanied with an extracted clear frame, is reached by devising a weighted importance criterion considering object clarity and face appearance. Besides, a spatial- domain cascaded transcoder is developed to convert the filtered image sequence of detected objects into the mobile video streaming format. Experimental results show that the system can successfully detect all events of moving objects for a complex surveillance scene, choose very appropriate key frames for users, and transcode the images with a high power signal-to-noise ratio （PSNR）.

关键词： Index Terms---Mobile video streaming moving object detection key frame extraction video surveillance video transcoding.

Injury-induced rapid activation of MAPK signaling in dechorionated eggs and larvae of the silkworm Bombyx mori

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Insect Science 2017年第2期24卷 248-258页

作者： Shi-Hong Gu Chien-hung chen Department of Biology National Museum of Natural Science Taichung Taiwan China Chung Hwa university of Medical Technol-ogy Tainan County Taiwan China

Previous study showed that diapause in Bombyx mori eggs can be ter- minated by dechorionation and that activation in the mitogen-activated protein kinase （MAPK）/extracellular signal-regulated kinase （ERK） in dechorionated cultured eggs is involved in diapause termination. In the present study, the possible mechanism underlying activation of ERK upon dechorionation was further investigated. Results showed that me- chanical injury of diapause eggs without medium incubation also resulted in rapid increase in the phospho-ERK levels and that injury increased the phospho-ERK levels at different stages of both diapause eggs and eggs in which diapause initiation was prevented by HC1. Effects of anaerobiosis on dechorionation-stimulated phospho-ERK levels showed that the mechanical injury itself but not the dramatic increase in oxygen uptake upon injury is in- volved in a rapid activation of ERK. Chemical anaerobiosis on dechorionation-stimulated phospho-ERK levels and the in vivo effect of anaerobiosis showed that the supply of oxygen also plays a role in ERK signaling. In addition, injury induced the phosphory- lation of c-jun N-terminal kinases （JNKs） and p38 kinase, components of two parallel MAPK pathways. A kinase assay showed a dramatic increase in .INK kinase activity in egg lysates upon injury. When newly hatched first instar larvae were injured, an increase in the phospho-ERK levels similar to that in dechorionated eggs was observed. From the results, we hypothesize that the injury-induced rapid activation of MAPK signaling, which serves as a natural signal for embryonic development, is related to diapause termination in dechorionated eggs.

关键词： Bombyx mori dechorionation embryonic diapause ERK phosphorylation injury MAPK

Study of Drift Behavior for RuO_x Sensing Membrane with Penicillinase Immobilized by GPTS

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稀有金属材料与工程 2006年第A03期35卷 228-229页

作者： Jung-Chuan Chou Sheng-hung chen Graduate School of Electronic Engineering National Yunlin University of Science and TechnologyDouliouTaiwan 640China

The ruthenium oxide(RuO_x) thin film was prepared by using the *** *** RuO_x pH-sensitive electrode possesses a nearly-Nernstian pH sensitivity(about 57 mV/pH).For the enzyme penicillinase was immobilized directly onto a RuO_x pH-sensitive surface by 3-glycidoxypropyltrimethoxysilane(GPTS).Some characteristics of the biosensor, such as sensitivity,linear range,and drift,are investigated and the difference between penicillinase immobilized and without are *** to the time-constant model,we can extract the time constant and amplitude at the response curve of the ***,the extracted parameters were used to simulate the mechanism of the drift behavior.

关键词： ruthenium oxide pH-sensitive electrode penicillinase drift behavior

Comparison of alternative route selection strategies based on simulation optimization

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Chinese Journal of Aeronautics 2016年第6期29卷 1749-1761页

作者： Ye Bojia Lance Sherry chen Chun-hung Tian Yong National Key Lab of Air Traffic Flow Management Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 210016China Center for Air Transportation Systems Research Department of Systems Engineering&Operations ResearchGeorge Mason UniversityFairfaxVA22030USA

Air traffic flow management(ATFM) is a collaborative process between the airspace provider and the airspace users. The result of the collaboration should be an outcome that maximizes the utility of the system without excessively penalizing any of the agents. This paper develops a discrete-event simulation model which consists of aggregate departure/arrival airports, flight routes, and sectors for evaluating the alternative collaborative route selection strategy. Given the different perspectives from air traffic control center(ACC) and airlines, eight performancemetrics and five alternative route selection strategies represent the past, current and proposed air traffic flow management operations that were evaluated. The Monte Carlo method combined with the Optimal Computing Budget Allocation(OCBA) simulation optimization technique is employed to assess the performance of different strategies. A case study of the upper air routes in central and southern China shows that the proposed model can be readily implemented to simulate different kinds of air traffic flow management strategies and predict the effect of changes on the airspace system. It also shows that the proposed alternative collaborative route selection strategy is an effective way in alleviating the en-route traffic congestion.

关键词： Air traffic control Decision support systems Discrete-event simulation Monte Carlo methods OCBA