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Fractional-order L<sub>β</sub>C<sub>α</sub> Low-Pass Filter Circuit
Zhou, Rui,Zhang, Run-Fan,Chen, Di-Yi The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4
This paper introduces the fundamentals of the conventional LC low-pass filter circuit in the fractional domain. First, we study the new fundamentals of fractional-order LC low-pass filter circuit including the pure real angular frequency, the pure imaginary angular frequency and the short circuit angular frequency. Moreover, sensitivity analysis of the impedance characteristics and phase characteristics of the LC low-pass filter circuit with respect to the system variables is studied in detail, which shows the greater flexibility of the fractional-order filter circuit in designs. Furthermore, from the filtering property perspective, we systematically investigate the effects of the system variables (LC, frequency f and fractional orders) on the amplitude-frequency characteristics and phase-frequency characteristics. In addition, the detailed analyses of the cut-off frequency and filter factor are presented. Numerical experimental results are presented to verify the theoretical results introduced in this paper.
Zhou, Rui,Nguyen, Hoang Nam,Sasase, Iwao The Korea Institute of Information and Commucation 2009 Journal of communications and networks Vol.11 No.5
In this paper, we propose a packet scheduling algorithm for cellular relay networks by considering relay selection, variation of channel quality, and packet delay. In the networks, mobile users are equipped with not only cellular but also user relaying radio interfaces, where base station exploits adaptive high speed downlink channel. Our proposed algorithm selects a user with good cellular channel condition as a relay station for other users with bad cellular channel condition but can get access to relay link with good quality. This can achieve flexible packet scheduling by adjusting transmission rates of cellular link. Packets are scheduled for transmission depending on scheduling indexes which are calculated based on user's achieved transmission rate, packet utility, and proportional fairness of their throughput. The performance results obtained by using computer simulation show that the proposed scheduling algorithm is able to achieve high network capacity, low packet loss, and good fairness in terms of received throughput of mobile users.
Aerodynamic performance evaluation of different cable-stayed bridges with composite decks
Rui Zhou,Yaojun Ge,Yongxin Yang,Yanliang Du,Lihai Zhang 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.5
The aerodynamic performance of long-span cable-stayed bridges is much dependent on its geometrical configuration and countermeasure strategies. In present study, the aerodynamic performance of three composite cable-stayed bridges with different tower configurations and passive aerodynamic countermeasure strategies is systematically investigated by conducting a series of wind tunnel tests in conjunction with theoretical analysis. The structural characteristics of three composite bridges were firstly introduced, and then their stationary aerodynamic performance and wind-vibration performance (i.e., flutter performance, VIV performance and buffeting responses) were analyzed, respectively. The results show that the bridge with three symmetric towers (i.e., Bridge I) has the lowest natural frequencies among the three bridges, while the bridge with two symmetric towers (i.e., Bridge II) has the highest natural frequencies. Furthermore, the Bridge II has better stationary aerodynamic performance compared to two other bridges due to its relatively large drag force and lift moment coefficients, and the improvement in stationary aerodynamic performance resulting from the application of different countermeasures is limited. In contrast, it demonstrates that the application of both downward vertical central stabilizers (UDVCS) and horizontal guide plates (HGP) could potentially significantly improve the flutter and vortex-induced vibration (VIV) performance of the bridge with two asymmetric towers (i.e., Bridge III), while the combination of vertical interquartile stabilizers (VIS) and airflowdepressing boards (ADB) has the capacity of improving the VIV performance of Bridge II.
Rui Zhou,Yongxin Yang,Yaojun Ge,Priyan Mendis,Damith Mohotti 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.21 No.2
Open decks are a widely used deck configuration in long-span cable-stayed bridges; however, incorporating aerodynamic countermeasures are advisable to achieve better aerodynamic performance than a bluff body deck alone. A sectional model of an open deck cable-stayed bridge with a main span of 400 m was selected to conduct a series of wind tunnel tests. The influences of five practical aerodynamic countermeasures on flutter and vortex-induced vibration (VIV) performance were investigated and are presented in this paper. The results show that an aerodynamic shape selection procedure can be used to evaluate the flutter stability of decks with respect to different terrain types and structural parameters. In addition, the VIV performance of Π-shaped girders for driving comfortableness and safety requirements were evaluated. Among these aerodynamic countermeasures, apron boards and wind fairings can improve the aerodynamic performance to some extent, while horizontal guide plates with 5% of the total deck width show a significant influence on the flutter stability and VIV. A wind fairing with an angle of 55° showed the best overall control effect but led to more lock-in regions of VIV. The combination of vertical stabilisers and airflow-depressing boards was found to be superior to other countermeasures and effectively boosted aerodynamic performance; specifically, vertical stabilisers significantly contribute to improving flutter stability and suppressing vertical VIV, while airflow-depressing boards are helpful in reducing torsional VIV
Full-scale test of dampers for stay cable vibration mitigation and improvement measures
Zhou, Haijun,Xiang, Ning,Huang, Xigui,Sun, Limin,Xing, Feng,Zhou, Rui Techno-Press 2018 Structural monitoring and maintenance Vol.5 No.4
This paper reported test of full-scale cables attached with four types of dampers: viscous damper, passive Magneto-Rheological (MR) damper, friction damper and High Damping Rubber (HDR) damper. The logarithmic decrements of the cable with attached dampers were calculated from free vibration time history. The efficiency ratios of the mean damping ratios of the tested four dampers to theoretical maximum damping ratio were derived, which was very important for practical damper design and parameter optimization. Non-ideal factors affecting damper performance were discussed based on the test results. The effects of concentrated mass and negative stiffness were discussed in detail and compared theoretically. Approximate formulations were derived and verified using numerical solutions. The critical values for non-dimensional concentrated mass coefficient and negative stiffness were identified. Efficiency ratios were approximately 0.6, 0.6, and 0.3 for the viscous damper, passive MR damper and HDR damper, respectively. The efficiency ratio for the friction damper was between 0-1.0. The effects of concentrated mass and negative stiffness on cable damping were positive as both could increase damping ratio; the concentrated mass was more effective than negative stiffness for higher vibration modes.
Fractional-order L<SUB>β</SUB>C<SUB>α</SUB> Low-Pass Filter Circuit
Rui Zhou,Run-Fan Zhang,Di-Yi Chen 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4
This paper introduces the fundamentals of the conventional LC low-pass filter circuit in the fractional domain. First, we study the new fundamentals of fractional-order LC low-pass filter circuit including the pure real angular frequency, the pure imaginary angular frequency and the short circuit angular frequency. Moreover, sensitivity analysis of the impedance characteristics and phase characteristics of the LC low-pass filter circuit with respect to the system variables is studied in detail, which shows the greater flexibility of the fractional-order filter circuit in designs. Furthermore, from the filtering property perspective, we systematically investigate the effects of the system variables (LC, frequency f and fractional orders) on the amplitude-frequency characteristics and phase-frequency characteristics. In addition, the detailed analyses of the cut-off frequency and filter factor are presented. Numerical experimental results are presented to verify the theoretical results introduced in this paper.
RUNES II : A Distributed Rule Engine Based on Rete Network in Cloud Computing
Rui Zhou,Guowei Wang,Jinghan Wang,Jing Li 보안공학연구지원센터 2014 International Journal of Grid and Distributed Comp Vol.7 No.6
In recent years, cloud computing has drawn more and more attention. Increasingly amount of systems and applications have been constructed in cloud environments, yet few researches of rule engine has been done. Rule engine technologies have been widely used in the development of enterprise information systems. These rule-based systems may encounter the problem of low performance, when a large amount of fact data are matched with these rules. Deploying rule engines in cloud environments can increase the capability and efficiency of these systems. In this paper, we propose an approach to implement rule engine based on a message-passing concurrency model in cloud computing. The approach can be extended conveniently and it can deal with extensive rules and facts efficiently. To improve the performance of the rule engine, an algorithm of allocation is proposed. A resource cost model is explored to make high efficient use of resources in cloud. In addition, we implement the rule engine system RUNES II in cloud platform and conduct experiments to show its performance.
Rui Zhou,Honghui Bao,강윤한 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.4
Polysaccharides from Auricularia auricula-judae (AP) have unique functionalities. The influence of APblending ratios (0.1–0.8%), temperature, pH, and ionic strength on the rheological interactions of yam starch (YS)–AP blends (YA, 6%) was investigated. YA gels showed shear-thinning behavior with flow-behavior indices of 0.28–0.37 and greater pseudoplasticity in the presence of 0.8% AP. With incremental AP addition, the viscosity and consistency indices significantly increased, whereas the activation energy decreased from 7.55 to 5.12 kJ/mol (p\0.05). YA gels exhibited excellent thickening and heat tolerance and behaved as weak gels over an AP concentration range of 0.1–0.4% but as true gels at higher concentrations (e.g. 0.8%). The viscosity/elasticity of the combinations weakened with NaCl addition or extreme pH values. A complex 3-dimensional network structure of the YA system was confirmed by scanning electron microscopy. These results indicated that AP has great potential for functional applications in the starchy food industry.
Rui Zhou,Wei Zhang,Jean W. Zu 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.7
This paper aims to investigate the nonlinear dynamics of a thin-plate workpiece during milling process with cutting force nonlinearities. By modeling the thin-plate workpiece as a cantilevered thin plate and applying the Hamilton’s principle, the equations of motion of thethin-plate workpiece are derived based on the Kirchhoff-plate theory and the von Karman strain-displacement relations. Using the Galerkin’sapproach, the equations of motion are reduced to a two-degree-freedom nonlinear system. The method of Asymptotic Perturbationis utilized to obtain the averaged equations in the case of 1:1 internal resonance and foundational resonance. Numerical methods areused to find the periodic and chaotic oscillations of the cantilevered thin-plate workpiece. The results show that the cantilevered thin-plateworkpiece demonstrate complex dynamic behaviors under time-delay effects, the external and parametric excitations.
Rui Zhou,강윤한 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.6
Thermal stable polysaccharides from Auricularia auricula-judae (AP) have unique molecularstructures and multiple bioactivities. The effects of AP on the physicochemical properties and in vitro starch digestibility of yam starch (YS) were studied. The addition of AP induced a significant increase in the swelling power, solubility, mean volume diameter and adhesiveness as well as a dramatic decrease in the hardness and gumminess (p\0.05). AP showed a strong suppressive effect on in vitro starch digestibility. Higher modulus (G0, G00) and stiffness parameters (Aa), and lower order of relaxation function (a), were observed in oscillatory rheological measurements, indicating that the gels were more elasticlike and had higher pseudoplasticity in the presence of AP. Furthermore, AP remarkably decreased the syneresis and storage modulus (G0), and also retarded the retrogradation process of YS gel at 4C, revealing a synergistic interaction between AP and YS, which could also be demonstrated by scanning electron microscopy.