Vertical Vibration of Strip Mill with the Piecewise Nonlinear Constraint arising from Hydraulic Cylinder

Fei Liu,Bin Liu,Hao-ran Liu,Yan-ling Gong,Song-jun Wang 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

Vertical vibration model of strip mill is established by considering piecewise nonlinear constraint arising from hydraulic cylinder. The approximate analytical solution of the model is obtained by incremental harmonic balance (IHB) method. The harmonic frequencies not conducive to stability are produced because the nonlinearity of the piecewise constraint. Bifurcation behavior of the system changes with external excitation amplitude and frequency ratio, intermittent chaos and periodic window are appeared alternately, the chaos region enlarged with the increasing piecewise interval. Compared with the piecewise linear constraint, the region of chaotic motion is widened obviously under the nonlinear constraint. Moreover, the critical condition of bifurcation and chaos behavior can be obtained from maximum Lyapunov exponent (MLE).

How “Foreign Influencer” Present Compelling Chinese Stories--Take “Chris”, a short video blogger in Tik Tok, as an example

Liu Jian(Jian Liu),Fei Jingying(Jingying Fei),Lv Mingkang(Mingkang Lv) 아시아사회과학학회 2022 International Science Research Vol.2 No.3

In recent years, a large number of excellent foreign short video bloggers have been active on major social media platforms, comparing the differences between Chinese and Western cultures, introducing Chinese traditional culture and customs to followers, and becoming a new force in telling Chinese stories. This paper takes the short video blogger “Chris” and his short videos as the research object, and analyze how “foreign influencer” tells Chinese stories in the new media environment, which brings new inspiration for telling Chinese stories and spreading Chinese voices well in the new media environment.

An Optimization Algorithm for Solving High-Dimensional Complex Functions Based on a Multipopulation Cooperative Bare-Bones Particle Swarm

Liu Cong,Liu Yunqing,Wu Tong,Yan Fei,Zhang Qiong 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

The particle swarm optimization (PSO) algorithm can easily become trapped in a local optimum when the objective function to be optimized is high-dimensional and complex. A multipopulation, cooperative, bare-bones particle swarm optimization (MCBBPSO) algorithm is proposed to solve this problem. In MCBBPSO, three types of parallel cooperative learning populations are used to optimize the objective function. By adding disturbance factors and adopting an elite reverse learning strategy, the optimization ability of the algorithm is increased. Through the “mirror wall” method, the cross-boundary particles are processed to reduce the loss of particle resources. Experiments using the CEC2013 standard test functions demonstrate the convergence accuracy and speed of the algorithm on high-dimensional and complex objective functions. Finally, MCBBPSO is applied to perform parameter optimization in support vector regression (SVR), and short-term wind speeds are then predicted using the optimized SVR approach to reduce resource consumption in a power grid.

Highly conductive graphene-based electrochemical sensor for ultrasensitive rotavirus detection

Fei LIU,Tae Seok SEO 한국생물공학회 2010 한국생물공학회 학술대회 Vol.2010 No.4

Fabrication of Carbonyl Iron Embedded Polycarbonate Composite Particles and Magnetorheological Characterization

Fei Fei Fang,Ying Dan Liu,Hyoung Jin Choi IEEE 2009 IEEE transactions on magnetics Vol.45 No.6

<P>Carbonyl iron (CI)-based magnetorheological (MR) fluid exhibits serious dispersion defect due to large density mismatch between CI particles and continuous medium, which obviously restricts further MR application. Thus, various modifications on CI particles have been explored, among which embedding CI particles within polymer matrix attracted much attention because the density of fabricated polymer/CI particles got considerably low, consequently enhancing the dispersion stability. In this paper, a more thermal stable polymer, polycarbonate (PC) with high strength, toughness, and heat resistance was adopted as polymer matrix, in which CI particles were randomly embedded via a facile solvent casting method. The embedding structure and density were confirmed by SEM/OM images and pycnometer, respectively. Finally, MR characterization was investigated.</P>

Migration Characteristics and Potential Ecological Environment Evaluation of Metal Elements in Surface Soil

Fei Liu,Zhong Yang,Ruihua Yang,Ruifeng Wang,Jianhai Zhou 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.5

In view of the excessive heavy metals in soil will affect the quality of crops and the personal safety of local residents, in order to analyze and evaluate the migration characteristics and potential ecological risks of heavy metals in soil in the study area, the heavy metal content, pH, regional distribution, correlation, migration characteristics, enrichment state and potential risk in 0 − 1 m soil depth were tested and analyzed. The results show that the distribution of most metal elements is closely related to pH in the soil. The contents of elements As, Cr and Hg in the soil of the study area change in an “L” shape along with the buried depth, that is, the contents of As, Cr and Hg increase generally along with the buried depth of the soil, and the contents of elements Cd and Pb decrease along with the buried depth. By analyzing the enrichment degree of heavy metals and evaluating the ecological risk degree, it can be concluded that only element Hg is moderately enriched in the soil layer of 0 − 0.4 m and Cd is the main ecological risk factor, and the potential ecological risk degree of Yuyao is between slight and moderate ecological risks.

한중 동물 속담의 문화적 의미 대조

Liu Xue Fei 한국어교육연구학회 2018 한국어교육연구 Vol.- No.9

옛날부터 동물과 인류는 관계(인연)를 깊이 맺어오고 있었기 때문에 인류의 생산과 생활 관계가 매우 밀접하다. 동시에 동물에 관한 속담은 오랫동안 민족의 정신문화에도 큰 영향을 미쳤다. 이번 논문에서는 한국과 중국의 동물에서 나타나는 출현 빈도가 높은 동물 속담을 조사하여 두 나라 사이의 언어와 문화이동 사례를 비교하고 분석해 보고자 한다. 한중 양국 동물에 관한 속담을 통해서 양국의 농사, 기후, 풍속, 생활습관과 욕 문화 등의 다양한 문화 차이를 볼 수 있다. 이를 통해서 또한 양국인의 사고방식과 언어 습관의 공통점과 차이점도 볼 수 있다. 본 논문은 한국어를 배우는 중국인, 중국어를 배우는 한국인에게 작은 도움이 될 수 있을 것이 바란다. 특히 오늘날과 같이 교류 현상이 두드러지고 있는 현실을 감안할 때에 이 연구의 필요성은 절실하다. Some of the Korean language norms, even if they are intended to be used by Korean users correctly, have a high incidence of the spelling errors due to the problem of regulation itself. An example is the more complicated and more cryptic rules by allowing different allomorph for forms that appear to have the same basic morpheme. Even if these regulations take maximum consideration of the characteristics of Korean language, there is a high possibility that the user will cause a spelling error from the beginning, compared to the simple rules. The purpose of this paper is to investigate the effect of the complexity of Korean language norms on the errors of the users spelling. In order to accomplish this purpose, this paper collected and analyzed errors in three types of morphemes which are spelled Korean users. As a result, the spelling error rate of Korean users was found to be very high. For example, in the case of ‘neolttarata’, the error rate is 211.8%, in the case of ‘subeol’, the error rate is 75%, in the case of ‘wicheung’, the error rate is 97.1%, compared to the correct spelling. This paper will be useful for revising related Korean language norms, which can improve the convenience and accuracy of spelling of Korean users in the future by verifying empirically the cases.

Control of Single-Molecule Junction Conductance of Porphyrins via a Transition-Metal Center

Liu, Zhen-Fei,Wei, Sujun,Yoon, Hongsik,Adak, Olgun,Ponce, Ingrid,Jiang, Yivan,Jang, Woo-Dong,Campos, Luis M.,Venkataraman, Latha,Neaton, Jeffrey B. American Chemical Society 2014 NANO LETTERS Vol.14 No.9

<P>Using scanning tunneling microscope break-junction experiments and a new first-principles approach to conductance calculations, we report and explain low-bias charge transport behavior of four types of metal–porphyrin–gold molecular junctions. A nonequilibrium Green’s function approach based on self-energy corrected density functional theory and optimally tuned range-separated hybrid functionals is developed and used to understand experimental trends quantitatively. Importantly, due to the localized d states of the porphyrin molecules, hybrid functionals are essential for explaining measurements; standard semilocal functionals yield qualitatively incorrect results. Comparing directly with experiments, we show that the conductance can change by nearly a factor of 2 when different metal cations are used, counter to trends expected from gas-phase ionization energies which are relatively unchanged with the metal center. Our work explains the sensitivity of the porphyrin conductance with the metal center via a detailed and quantitative portrait of the interface electronic structure and provides a new framework for understanding transport quantitatively in complex junctions involving molecules with localized d states of relevance to light harvesting and energy conversion.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2014/nalefd.2014.14.issue-9/nl5025062/production/images/medium/nl-2014-025062_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl5025062'>ACS Electronic Supporting Info</A></P>

The Cooperative Effect Analysis when Nanoparticles Enter a Biological Cell

Fei Liu,Dan Wu,Ken Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.4

The nanoparticle (NP) is one of the most used nanostructures in biomedicine. The Np–biomembrane interface plays an important role in delivering NPs into a living biological cell. While most researchers focus on the interaction between a single Np and a cell membrane, we pay attention to the NP–biomembrane interaction when a cluster of NPs are put into a biological cell together, and analyze the cooperative effect of these NPs. We find that the NPs would not enter the cell individually, but have a trend to form an aggregation to reduce the repel force from the cell membrane. The dissipative particle dynamics simulation shows that the NP aggregation may have three interactive states with the membrane: adhere on the surface of the cell, uptaken by the membrane and enter the cell. We propose to use catalytic (CA) particles which are not sensitive to the membrane to reduce the driving force required in NP delivery. Energy analysis demonstrates that the introduced (CA) particles can decrease the free energy gap between the inside and the outside of the membrane, and increase the success rate of NPs entering the cell.

Photoluminescent Graphene Oxide Microarray for Multiplex Heavy Metal Ion Analysis

Fei Liu,Hyun Dong Ha,Dong Ju Han,Min Su Park,Tae Seok Seo 한국진공학회 2013 한국진공학회 학술발표회초록집 Vol.2013 No.8