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H∞ synchronization of chaotic neural networks with time-varying delays

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Chinese Physics B 2013年第11期22卷 244-252页

作者： O. m. Kwon m. J. park Ju H. park S. m. Lee E. J. Cha School of Electrical Engineering Chungbuk National University Department of Electrical Engineering Yeungnam University School of Electronic Engineering Daegu University Department of Biomedical Engineering School of Medicine Chungbuk National University

In this paper, we investigate the problem of H∞ synchronization for chaotic neural networks with time-varying delays. A new model of the networks with disturbances in both master and slave systems is presented. By constructing a suitable Lyapunov–Krasovskii functional and using a reciprocally convex approach, a novel H∞ synchronization criterion for the networks concerned is established in terms of linear matrix inequalities （LmIs） which can be easily solved by various effective optimization algorithms. Two numerical examples are given to illustrate the effectiveness of the proposed method.

关键词： chaotic neural networks time-varying delays H∞ synchronization Lyapunov method

mICROSTRUCTURE AND mECHANICAL PROPERTIES OFP/m TiAl ALLOyS AND THE TEmPERATURE EFFECT

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Acta metallurgica Sinica(English Letters) 1998年第6期11卷 417-424页

作者： Z.m.Sun H.Hashimoto S.Sumi y.H.park T.Abe Z.H.Shan Tohoku Natl Industrial Research Inst Sendai Japan

Two intermetallic compounds of Ti-50at.%Al and Ti-48at.%Al-2at.%Cr were prepared with a mechanical alloying and pulse discharge sintering process. The as-sintered material shows a microstructure of equiaxed gamma grain with sub-micron size. Heat treatments in Vacuum at different temperatures up to 1573 K were conducted on the sintered materials. The microstructure of the material coarsened considerably after heat treatment at temperatures higher than 1523 K. The mechanical properties of the as-sintered and the heat treated materials were measured at temperatures up to 973 K, with four-point bending tests. Experimental results indicate that the addition of Cr increases the fracture strength of the intermetallic compound at room temperature and at elevated temperatures as well. The bending fracture strength increases with increasing testing temperature up to about 873 K and a decrease following up. Both fracture strength and fracture strain of the material were found to be improved by heat treatment. (Edited author abstract) 10 Refs.

关键词： titanium aluminide mechanical alloying heat treatment mechanical property temperature

A Collocation Technique via Pell-Lucas Polynomials to Solve Fractional Differential Equationmodel for HIV/AIDS with Treatment Compartment

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Computer modeling in Engineering & Sciences 2024年第10期141卷 281-310页

作者： Gamze yıldırım Suayip yüzbası Department of mathematics Faculty of ScienceAkdeniz UniversityAntalya07058Turkey Department of mathematics Faculty of Basic ScienceGebze Technical UniversityKocaeli41400Turkey Department of mathematics Faculty of ScienceBartın UniversityBartın74100Turkey

In this study,a numerical method based on the Pell-Lucas polynomials(PLPs)is developed to solve the fractional order HIV/AIDS epidemic model with a treatment *** HIV/AIDS mathematical model with a treatment compartment is divided into five classes,namely,susceptible patients(S),HIV-positive individuals(I),individuals with full-blown AIDS but not receiving ARV treatment(A),individuals being treated(T),and individuals who have changed their sexual habits sufficiently(R).According to the method,by utilizing the PLPs and the collocation points,we convert the fractional order HIV/AIDS epidemic model with a treatment compartment into a nonlinear system of the algebraic ***,the error analysis is presented for the Pell-Lucas approximation *** aim of this study is to observe the behavior of five populations after 200 days when drug treatment is applied to HIV-infectious and full-blown AIDS *** demonstrate the usefulness of this method,the applications are made on the numerical example with the help of *** addition,four cases of the fractional order derivative(p=1,p=0.95,p=0.9,p=0.85)are examined in the range[0,200].Owing to applications,we figured out that the outcomes have quite decent ***,we understand that the errors decrease when the value of N *** figures in this study are created in *** outcomes indicate that the presented method is reasonably sufficient and correct.

关键词： Collocation method fractional differential equations HIV/AIDS epidemic model Pell-Lucas polynomials

Optimization of a fermented pumpkin-based beverage to improve Lactobacillus mali survival and-glucosidase inhibitory activity:A response surface methodology approach

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Food Science and Human Wellness 2018年第1期7卷 57-70页

作者： W.y.Koh U.Uthumporn A.Rosma A.R.Irfan y.H.park Food Technology Division School of Industrial TechnologyUniversiti Sains MalaysiaMinden 11800PenangMalaysia Bioprocess Division School of Industrial TechnologyUniversiti Sains MalaysiaMinden 11800PenangMalaysia Department of Applied microbiology and Biotechnology Yeungnam UniversityGyeongsanSouth Korea

The aim of this research was to develop an optimum fermentation and composition model for a new fermented pumpkin-based beverage with high probiotic survival and-glucosidase inhibitory *** between fermentation temperature,inoculum and ingredient concentration with response variables(fermentation time at the fermentation endpoint pH 4.5,survival rate of Lactobacillus mali K8 in pumpkin-based beverage treated with simulated gastrointestinal tract enzyme fluids,-glucosidase inhibitory activity and sensory overall acceptability after 4 weeks of refrigerated storage)was investigated using response surface *** formulation was obtained at an approximation of 40%pumpkin puree concentration,8 Log CFU/mL inoculum and at 35℃.The product derived from this optimum formula reached the fermentation endpoint after 28.34±0.10 h and the quality change during 4 weeks storage was *** product achieved 88.56±0.67%of *** survival after treatment with simulated gastric and intestinal juices;demonstrated 95.89±0.30% α-glucosidase inhibitory activity,as well as scored 6.99±0.40 on sensory overall acceptability after 4 weeks of *** findings illustrated that the model is effective in improving probiotic survival and α-glucosidase inhibitory activity with excellent sensory acceptability,thus may offer a dietary means for the management of hyperglycaemia.

关键词： Probiotics Response surface methodology Box-Behnken Hyperglycaemia Functional food

Synthesis of an Anti-1,3-Diol Type Chiral Building Block

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Chinese Chemical Letters 1998年第11期9卷 987-988页

作者： Wu, y Guan, m W China Univ med Sci Sch Pharm Chengdu 610041 Peoples R China W China Univ med Sci Hosp 1 Chengdu 610041 Peoples R China

A chiral building block, anti-1,3-diol 2, has been synthesized in 7 steps, starting from readily available and inexpensive D-(+)-xylose.

关键词： chiral building block anti-1,3-Diol D(+)-xylose

A stochastic approach for integrating market and technical uncertainties in economic evaluations of petroleum development

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Petroleum Science 2009年第3期6卷 319-326页

作者： Changhyup park Joe m. Kang Taewoong Ahn BK21 Research Division for Energy Resources Seoul National University Division of Energy Systems Engineering Seoul National University

The paper presents a stochastic and economic analysis for petroleum development under uncertain market and technical environments. mean-reversion with jumps for price forecasting is used to consider market uncertainty, while various scenarios for the reservoir properties and cost are employed to consider technical uncertainty. monte Carlo simulation is carried out to obtain the feasible range of net present values and internal rates of return. The influence of stochastic parameters is examined through correlation coefficients. The stochastic approach yields more reliable evaluation and effectively investigates the characteristics of development. The integration of uncertainties and contractual terms results in an irregular tendency in the future cash flow and reveals that a larger reserve does not guarantee a greater profit. The reserve and the well rate affect the economic values whereas the parameters for price prediction don＇t. The research confirms the necessity of qualifying uncertainties for realistic decision-making at the initial stage of development.

关键词： Uncertainty petroleum development decision-making stochastic approach mean reversion with jumps

Dynamic Response of mold Oscillator Interacting with Steel Slabs

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Journal of Iron and Steel Research International 2016年第9期23卷 900-909页

作者： yonghui park Hyunchul park Graduate School of Engineering masterships Pohang University of Science and Technology(POSTECH)

A mathematical model to show the dynamic response of the mold oscillator was suggested. The model con- sidered a frictional interaction between the mold oscillator and slab as several connected nodes. The governing equation considered the slab as a multi-degree-of-freedom （DoF） system, and included a hysteresis model to describe elastic-plastic behavior of the slab; the mold oscillator was given two DoF by utilizing pressure and displacement experiment data. Simulations indicate that the mold and slab execute various vibrations, and that mold oscillation marks are caused by a stick-and-slip phenomenon during intervals, in which the slab contacting the mold moves downward compared to the other slab （negative strip time）. The slab shows the formation of mold oscillation marks to previous formation criterion equally when the mold velocity is faster than the casting speed about downward. The oscillation mark will grow up over 2 Hz exciting frequency with constant 4 mm stroke in simulations. Finally, the negative strip time was compared to the frictional force, hysteresis variable, and plastic force to investigate formation mechanism of the oscillation marks.

关键词： mold oscillating mechanism mathematical model direct integration method hysteresis model stick-and-slip

Quantified evaluation of particle shape effects from micro-to-macro scales for non-convex grains

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Particuology 2016年第2期14卷 23-35页

作者： y. yang J.F. Wang y.m. Cheng Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hong Kong China Department of Civil and Architectural Engineering City University of Hong Kong Hong Kong China

Particle shape plays an important role in both the micro and macro scales responses of a granular assem- bly. This paper presents a systematic way to interpret the shape effects of granular material during quasi-static shearing. A more suitable shape descriptor is suggested for the quantitative analysis of the macroscale strength indexes and contact parameters for non-convex grains, with special consid- eration given to the peak state and critical state. Through a series of numerical simulations and related post-processing analysis, particle shape is found to directly influence the strain localisation patterns, microscale fabric distributions, microscale mobilisation indexes, and probability distribution of the nor- malised contact normal force. Additionally, the accuracy of the stress-force-fabric relationship can be influenced by the average normal force and the distribution of contact vectors. moreover, particle shape plays a more important role than do the confining pressures in determining the friction angle. Strong force chains and the dilation effect are also found to be strongly influenced by the high confinin~ oressure.

关键词： Quantitative analysis Shape factor Statistical analysis micro-macro indexes

PREPARATION AND CHARACTERIZATION OF SCHIFF BASE POLymERS DERIVED FROm 4,4'-mETHyLENEBIS(CINNAmALDEHyDE)

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Chinese Journal of Polymer Science 2007年第4期25卷 399-407页

作者： m.y. Khuhawar A. Shah m.A. mughal Dr. m.A. Kazi Institute of Chemistry University of SindhJamshoroSindhPakistan

New Schiff base polymers poly[4,4＇-methylenebis（cinnamaldehyde）ethylenediimine] （PmBCen）, poly[4,4＇- methylenebis（cinnamaldehyde）1,2-propylenediimine] （PmBCPn）, poly[4,4＇-methylenebis（cinnamaldehyde）1,3-propylenediimine] （PmBCPR）, poly[4,4＇-methylenebis（cinnamaldehyde） 1,2-phenylenediimine] （PmBCPh）, poly[4,4＇-methylenebis（cinnamaldehyde）meso-stilbenediimine] （PmBCS）, poly[4,4＇-methylenebis（cinnamaldehyde）urea] （PmBCUR）, poly[4,4＇- methylenebis（cinnamaldehyde）semicarbazone] （PmBCSc）, poly[4,4＇-methylenebis（cinnamaldehyde）thiosemicarbazone] （PmBCTSc） and poly[4,4＇-methylenebis（cinnamaldehyde）hydrazone] （PmBCH） were formed by polycondensation of 4,4＇- methylenebis（cinnamaldehyde） with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and ^1H-NmR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.

关键词： Schiff base polymers Synthesis Characterization Infrared spectroscopy Ultraviolet-visible spectroscopy Nuclear magnetic resonance Thermogravimetric analysis Differential thermal analysis.