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Lagrangian-based investigation of multiphase flows by finite-timeLyapunov exponents

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Acta Mechanica Sinica 2012年第3期28卷 612-624页

作者： Jia-Ning Tang chien-chou Tseng Ning-FeiWang School of Aerospace Engineering Beijing Institute of Technology100081 Beijing China Department of Mechanical and Electro-Mechanical Engineering National Taiwan Sun Yat-Sen UniversityKaohsiung Taiwan China Department of Aerospace Engineering University of Michigan Ann ArborM148109 USA

Multiphase flows are ubiquitous in our daily life and engineering applications. It is important to investigate the flow structures to predict their dynamical behaviors ef- fectively. Lagrangian coherent structures （LCS） defined by the ridges of the finite-time Lyapunov exponent （FTLE） is utilized in this study to elucidate the multiphase interactions in gaseous jets injected into water and time-dependent turbu- lent cavitation under the framework of Navier-Stokes flow computations. For the gaseous jets injected into water, the highlighted phenomena of the jet transportation can be observed by the LCS method, including expansion, bulge, necking/breaking, and back-attack. Besides, the observation of the LCS reveals that the back-attack phenomenon arises from the fact that the injected gas has difficulties to move toward downstream re- gion after the necking/breaking. For the turbulent cavitating flow, the ridge of the FTLE field can form a LCS to capture the front and boundary of the re-entraint jet when the ad- verse pressure gradient is strong enough. It represents a bar- rier between particles trapped inside the circulation region and those moving downstream. The results indicate that the FFLE field has the potential to identify the structures of mul- tiphase flows, and the LCS can capture the interface/barrier or the vortex/circulation region.

关键词： Finite-time Lyapunov exponents Lagrangiancoherent structures Multiphase flow Gaseous jets injectedinto water Cavitation

Modeling of turbulent,isothermal and cryogenic cavitation under attached conditions

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Acta Mechanica Sinica 2010年第3期26卷 325-353页

作者： chien-chou Tseng Yingjie Wei GuoyuWang Wei Shyy Department of Mechanical Engineering University of Michigan2350 Hayward Ann Arbor MI 48109 USA School of Astronautics Harbin Institute of Technology 92 West Da-Zhi Street Harbin 150001 China School of Vehicle and Transportation Engineering Beijing Institute of Technology 5 South Zhongguancun Street Beijing 100081 China Department of Aerospace Engineering University of Michigan 1320 Beal Ann Arbor MI 48109 USA

Cavitation is often triggered when the fluid pres- sure is lower than the vapor pressure at a local thermo- dynamic state. The present article reviews recent progress made toward developing modeling and computational strat- egies for cavitation predictions under both isothermal and cryogenic conditions, with an emphasis on the attached cav- ity. The review considers alternative cavitation models along Reynolds-averaged Navier-Stokes and very lager eddy simu- lation turbulence approaches to ensure that the computational tools can handle flows of engineering interests. Observing the substantial uncertainties associated with both modeling and experimental information, surrogate modeling strategies are reviewed to assess the implications and relative impor- tance of the various modeling and materials parameters. The exchange between static and dynamic pressures under the influence of the viscous effects can have a noticeable impact on the effective shape of a solid object, which can impact the cavitation structure. The thermal effect with respect to evaporation and condensation dynamics is examined to shed light on the fluid physics associated with cryogenic cav- itation. The surrogate modeling techniques are highlighted in the context of modeling sensitivity assessment. Keywords

关键词： Cavitation Cryogenic liquidThermal effects Turbulence model - Surrogate model

A Model for Analyzing the Transshipment Competition Relationship Between the Port of Hong Kong and the Port of Kaohsiung

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Journal of Ocean University of China 2009年第4期8卷 377-384页

作者： chou chien Chang Department of Shipping Technology Kaohsiung Marine University Kaohsiung 805 Taiwan China

The transshipment is an important issue in the current marine transportation. This paper constructed a mathematical programming model to elaborate the transshipment port selection for the shipping company. This model is tested by the data collected from the ports of Hong Kong and Kaohsiung. The results show that this model can be used to explain the transshipment competition relationship between the ports of Hong Kong and Kaohsiung well. A sensitivity analysis was also executed. The sensitivity analysis results showed that both the port of Hong Kong and Kaohsiung should decrease the charges of port and increase the effi- ciency of loading and discharging. Based on the sensitivity analysis results, some interesting conclusions and helpful suggestions were obtained for the managers of the ports of Hong Kong and Kaohsiung to improve their port management.

关键词： transshipment mathematical programming port of Hong Kong port of Kaohsiung

Glucose detection in a highly scattering medium with diffuse photon-pair density wave

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Journal of Innovative Optical Health Sciences 2017年第1期10卷 53-58页

作者： Li-Ping Yu Jheng-Syong Wu Sheng-Yi Chang chien chou Biomedical Engineering Research Center Chang Gung University Taoyuan 333Taiwan Graduate Institute of Electro-Optical Engineering Chang Gung University Taoyuan 333Taiwan Institute of Chemistry A cademic SinicaNankangTaipei 115Taiwan Ph.D Program of Biomedical Engineering Chang Gung University Taoyuan 333Taiwan Department of Mechanics Ming Chi University of Technology New Taipei 243Taiwan

We propose a novel optical method for glucose measurement based on difuse photon-pair density wave(DPPDW)in a multiple scattering medium(MSM)where the light scattering of photon-pair is induced by refractive index mismatch between scatters and phantom ***-mentally,the DPPDW propagates in MSM via a two frequency laser(TFL)beam wherein highly correlated pairs of linear polarized photons are *** reduced scattering coefficientμ2s and absorption coefficientμ2a of DPPDW are measured simultaneously in terms of the amplitude and phase measurements of the detected heterodyne signal under arrangement at different dis-tances between the source and detection fibers in *** results show that the sensitivity of glucose detection via glucose-induced change of reduced scattering coefficient(δμ′2)is 0.049%mM^(-1)in a 1%intralipid *** addition,the linear range ofδμ′2s vs glucose concentration implies that this DPPDW method can be used to monitor glucose concentration continuously and noninvasively subcutaneously.

关键词： Difuse photon-pair density wave glucose multiple scattering polarization gating spatial coherence gating.

Surrogate-based modeling and dimension reduction techniques for multi-scale mechanics problems

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Acta Mechanica Sinica 2011年第6期27卷 845-865页

作者： Wei Shyy Young-Chang Cho Wenbo Du Amit Gupta chien-chou Tseng Ann Marie Sastry Hong Kong University of Science and Technology Clear Water Bay Hong Kong China University of Michigan Ann Arbor MI USA National Taiwan Sun Yat-Sen University Kaohsiung Taiwan China

Successful modeling and/or design of engineering systems often requires one to address the impact of multiple ＂design variables＂ on the prescribed *** are often multiple,competing objectives based on which we assess the outcome of *** accurate,high fidelity models are typically time consuming and computationally expensive,comprehensive evaluations can be conducted only if an efficient framework is ***,informed decisions of the model/hardware＇s overall performance rely on an adequate understanding of the global,not local,sensitivity of the individual design variables on the *** surrogate-based approach,which involves approximating the objectives as continuous functions of design variables from limited data,offers a rational framework to reduce the number of important input variables,i.e.,the dimension of a design or modeling *** this paper,we review the fundamental issues that arise in surrogate-based analysis and optimization,highlighting concepts,methods,techniques,as well as modeling implications for mechanics *** aid the discussions of the issues involved,we summarize recent efforts in investigating cryogenic cavitating flows,active flow control based on dielectric barrier discharge concepts,and lithium（Li）-ion *** is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for ＂scale bridging.＂

关键词： Multi-scale mechanics ~ Cryogenic cavitating flow Surrogate-based modeling Active flow control Engineering system

POLARIZATION-SENSITIVE OPTICAL COHERENCE TOMOGRAPHY USING A MODIFIED BALANCE DETECTOR

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Journal of Innovative Optical Health Sciences 2012年第4期5卷 18-23页

作者： LI-PING YU JIAN-CHEN GUO LI-DEK chou TE-LUN MA JHENG-SYONG WU JIANN-DER LEE chien chou Center for Biomedical Engineering Chang Gung University Taoyuan 333 Taiwan Department of Biomedical Imaging and Radiological Science National Yang Ming University Taipei 112 Taiwan Graduate Institute of Electro-Optical Engineering Chang Gung University Taoyuan 333 Taiwan Department of Optics and Photonics National Central University Jhongli 320 Taiwan Department of Electrical Engineering Chang Gung University Taoyuan 333 Taiwan Graduate Institute of Electro-Optical Engineering and Center for Biomedical Engineering Chang Gung University Taoyuan 333 Taiwan

In conventional polarization sensitive optical coherence tomography(PS-OCT),phase retar-dation is obtained by the amplitude of P and S polarization only,and the fast axis angle is obtained by the phase difference in P and S polarizations via Hilbert *** this paper,we proposed a modifed PS OCT setup in which the phase retardation and fast axis angle are simply expressed as the function of the amplitude ofP and S polarization and their differential *** to the common-path feature between the two channels ofP and S polarization,the fuctuation in the measurement of phase retardation and fast axis angle caused by excess noise and phase noise from the laser source can be reduced by the differential signal of P and S polarization via a modified balance ***,the signal of phase retardation and fast angle axis in the deep layer of a porcine sample can be improved.

关键词： PS OCT modifed balanced detector Hilbert transformation

Optimization Model for Selecting Temporary Hospital Locations During COVID-19 Pandemic

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Computers, Materials & Continua 2022年第1期70卷 397-412页

作者： Chia-Nan Wang chien-Chang chou Hsien-Pin Hsu Van Thanh Nguyen Viet Tinh Nguyen Department of Industrial Engineering and Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Department of Shipping Technology National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Department of Supply Chain Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Faculty of Commerce Van Lang UniversityHo Chi Minh City70000Vietnam

The two main approaches that countries are using to ease the strain on healthcare infrastructure is building temporary hospitals that are specialized in treating COVID-19 patients and promoting preventive *** such,the selection of the optimal location for a temporary hospital and the calculation of the prioritization of preventive measures are two of the most critical decisions during the pandemic,especially in densely populated areas where the risk of transmission of the virus is *** the location selection process or the prioritization of measures is poor,healthcare workers and patients can be harmed,and unnecessary costs may come into *** this study,a decision support framework using a fuzzy analytic hierarchy process(FAHP)and a weighted aggregated sum product assessment model are proposed for selecting the location of a temporary hospital,and a FAHP model is proposed for calculating the prioritization of preventive measures against COVID-19.A case study is performed for Ho Chi Minh City using the proposed decision-making *** contribution of this work is to propose a multiple criteria decision-making model in a fuzzy environment for ranking potential locations for building temporary hospitals during the COVID-19 *** results of the study can be used to assist decisionmakers,such as government authorities and infectious disease experts,in dealing with the current pandemic as well as other diseases in the *** the entire world facing the global pandemic of COVID-19,many scientists have applied research achievements in practice to help decision-makers make accurate decisions to prevent the *** the number of cases increases exponentially,it is crucial that government authorities and infectious disease experts make optimal decisions while considering multiple quantitative and qualitative *** such,the proposed approach can also be applied to support complex decision-making processes in a fuzzy environment in di

关键词： COVID-19 WHO MCDM preventive measures fuzzy theory FAHP WASPAS

Two-Stage Production Planning Under Stochastic Demand:Case Study of Fertilizer Manufacturing

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Computers, Materials & Continua 2022年第1期70卷 1195-1207页

作者： Chia-Nan Wang Shao-Dong Syu chien-Chang chou Viet Tinh Nguyen Dang Van Thuy Cuc Department of Industrial Engineering and Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Sunline NP Telecommunications Co.Ltd Kaohsiung80778Taiwan Department of Shipping Technology National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Faculty of Commerce Van Lang UniversityHo Chi Minh City70000Vietnam Faculty of Industrial Engineering and Management International UniversityHo Chi Minh City70000Vietnam

Agriculture is a key facilitator of economic prosperity and nourishes the huge global *** achieve sustainable agriculture,several factors should be considered,such as increasing nutrient and water efficiency and/or improving soil health and *** fertilizer is one of the fastest and easiest ways to improve the quality of nutrients inland and increase the effectiveness of crop *** supplies most of the necessary nutrients for plants,and it is estimated that at least 30%-50%of crop yields is attributable to commercial fertilizer nutrient *** is always a major concern in achieving sustainable and efficient *** reasonable and customized fertilizerswill require a significant increase in the number of formulae,involving increasing costs and the accurate forecasting of the right time to apply the suitable *** alternative solution is given by two-stage production planning under stochastic demand,which divides a planning schedule into two *** primary stage has non-existing demand information,the inputs of which are the proportion of raw materials needed for producing fertilizer products,the cost for purchasing materials,and the production *** total quantity of purchased material and produced products to be used in the blending process must be defined to meet as small as possible a paid *** the second stage,demand appears under multiple scenarios and their respective *** stage will provide a solution for each occurring scenario to achieve the best *** two-stage approach is presented in this paper,the mathematical model of which is based on linear integer *** the diversity of fertilizer types,themathematicalmodel can advise manufacturers about which products will generate as much as profit as ***,two objectives are taken into ***,the paper’s thesis focuses on minimizing overall system costs,e.g.,including inventory cost,pur

关键词： Two-stage stochastic programming demand uncertainty planning blending fertilizer

Particle Swarm Optimization for Identifying Rainfall-Runoff Relationships

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Journal of Water Resource and Protection 2012年第3期4卷 115-126页

作者： chien-Ming chou Department of Design for Sustainable Environment Ming Dao University Changhua Chinese Taipei

Rainfall-runoff processes can be considered a single input-output system where the observed rainfall and runoff are inputs and outputs, respectively. Conventional models of these processes cannot simultaneously identify unknown structures of the system and estimate unknown parameters. This study applied a combinational optimization and Particle Swarm Optimization (PSO) for simultaneous identification of system structure and parameters of the rainfall-runoff relationship. Subsystems in proposed model are modeled using combinations of classic models. Classic models are used to transform the system structure identification problem into a combinational optimization and can be selected from those typically used in the hydrological field. A PSO is then applied to select the optimized subsystem model with the best data fit. The parameters are estimated simultaneously. The proposed model is tested in a case study of daily rainfall-runoff for the upstream Kee-Lung River. Comparison of the proposed method with simple linear model (SLM) shows that, in both calibration and validation, the PSO simulates the time of peak arrival more accurately compared to the SLM. Analytical results also confirm that the PSO accurately identifies the system structure and parameters of the rainfall-runoff relationship, which are a useful reference for water resource planning and application.

关键词： Rainfall-Runoff System Identification Particle Swarm Optimization Classic Models Simple Linear Model