An Energy Aware Cellular Learning Automata Based Routing Algorithm for Opportunistic Networks

Feng Zhang,Xiaoming Wang,Peng Li,Lichen Zhang 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.2

Message transmission in opportunistic networks is accomplished via the encounters of mobile nodes while moving around. The distributing of nodes greatly impacts the performance of message delivery ratio due to their sparse encounter opportunities. Nodes with exhaust energy can’t participate in message transfer process. So it is very meaningful to make nodes energetic and balance the energy consumption between nodes. In this paper, a novel dynamic irregular cellular multiple learning automata (DICMLA) model and the corresponding routing algorithm are proposed to optimize the energy consumption of nodes. The proposed routing algorithm utilizes the characteristics of cellular learning automata to reduce the energy consumption of nodes and improve the delivery ratio of message transmission. The simulation results show that the proposed algorithm can obviously balance energy consumption of nodes and thus prolong the lifetime of the network.

The inclusion measure and information energy for hesitant fuzzy sets and their application in decision making

Feng Zhang,Zhaohao Wang 원광대학교 기초자연과학연구소 2017 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.14 No.4

Inclusion measure of hesitant fuzzy sets is an important subject in the theory of hesitant fuzzy set, and it has been studied and widely used in clustering analysis and decision making. In this paper, we aim at constructing inclusion measure for hesitant fuzzy sets based on fuzzy sets. The axiomatical definition of inclusion measure for hesitant fuzzy sets is firstly proposed, and we construct a new inclusion relation for hesitant fuzzy sets. Based on this new inclusion relation, different inclusion measures based on the inclusion measures of fuzzy sets for hesitant fuzzy sets are further constructed. In addition, in order to describe the fuzziness degree of HFSs, information energy for HFSs is introduced. Finally, a real example about hesitant fuzzy multi-attribute decision making is used to illustrate the validity and applicability of the proposed inclusion measures and information energies.

Single-pass capacitive deionization with a HNO3-modified electrode for fluoride removal

Feng Zhang,Fan Yang 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.1

HNO3-modified activated carbon was used to make electrodes for single-pass capacitive deionization for removing F− from drinking water. The optimal operating conditions for F− removal were studied, and the F− removal performance, cycle stability, and charge efficiency of the electrode were investigated. Based on these results, an optimization scheme was proposed for practical applications. After HNO3 modification, the proportion of micropores, specific surface area, and number of oxygen-containing functional groups on the activated-carbon surface increased, resulting in a significant increase in the specific capacitance of the electrode. Under optimal operating conditions, the adsorption capacity of the modified electrode was 13% higher than that of the unmodified electrode, while the charge efficiency increased by 25% and reached a peak value after about 1,100 s. The HNO3-modified electrode had good cycle stability, and maintained 83% of the original adsorption capacity after 5 cycles. Optimizing the adsorption time (1,500 s) and desorption time (900 s), 80% of the specific adsorption capacity was maintained after 5 cycles. In addition, the cycle time was reduced by 32%, and the utilization rate of electric-double-layer adsorption sites was optimized, resulting in a reduction in the energy consumption per unit F− removal.

Manipulator-actuated Adaptive Integrated Translational and Rotational Stabilization for Spacecraft in Proximity Operations with Control Constraint

Feng Zhang,Guang Ren Duan 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.5

This paper tackles the problem of integrated translation and rotation stabilization of the spacecraft in proximity operations by proposing a novel manipulator actuation strategy. To do so, by theoretically integrating the attitude/position motion of the spacecraft and the joint motion of the manipulator, a coupled translational and rotational kinematics of the spacecraft with a single space manipulator mounted is formulated, where system unknown parameters and residual system momentum are taken into account and analyzed. Taking the joint motion as the control input, a projection-based adaptive control scheme is then developed such that the translation and rotation of the spacecraft can be robustly stabilized with the manipulator-based actuation. The closed-loop asymptotic stability is guaranteed within Lyapunov framework. Meanwhile, considering the constrained joint motion of the manipulator, the resulting control constraint issue is handled by developing an optimization based bound analysis method, which also facilitates the determination of control parameters. Two scenario numerical simulations demonstrate the effect of the designed control scheme.

Complexity of continuous semi-flows and related dynamical properties

Feng Zhang,Lian-Fa He,Qi-Shao Lu 대한수학회 2009 대한수학회지 Vol.46 No.2

The equicontinuity and scattering properties of continuous semi-flows are studied on a compact metric space. The main results are obtained as follows: first, the complexity function defined by the spanning set is bounded if and only if the system is equicontinuous; secondly, if a continuous semi-flow is topologically weak mixing, then it is pointwise scattering; thirdly, several equivalent conditions for the time-one map of a continuous semi-flow to be scattering are presented; Finally, for a minimal continuous map it is shown that the ``non-dense" requirement is unnecessary in the definition of scattering by using open covers. The equicontinuity and scattering properties of continuous semi-flows are studied on a compact metric space. The main results are obtained as follows: first, the complexity function defined by the spanning set is bounded if and only if the system is equicontinuous; secondly, if a continuous semi-flow is topologically weak mixing, then it is pointwise scattering; thirdly, several equivalent conditions for the time-one map of a continuous semi-flow to be scattering are presented; Finally, for a minimal continuous map it is shown that the ``non-dense" requirement is unnecessary in the definition of scattering by using open covers.

Dynamic Adjustment Strategy of n-Epidemic Routing Protocol for Opportunistic Networks: A Learning Automata Approach

( Feng Zhang ),( Xiaoming Wang ),( Lichen Zhang ),( Peng Li ),( Liang Wang ),( Wangyang Yu ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.4

In order to improve the energy efficiency of n-Epidemic routing protocol in opportunistic networks, in which a stable end-to-end forwarding path usually does not exist, a novel adjustment strategy for parameter n is proposed using learning atuomata principle. First, nodes dynamically update the average energy level of current environment while moving around. Second, nodes with lower energy level relative to their neighbors take larger n avoiding energy consumption during message replications and vice versa. Third, nodes will only replicate messages to their neighbors when the number of neighbors reaches or exceeds the threshold n. Thus the number of message transmissions is reduced and energy is conserved accordingly. The simulation results show that, n-Epidemic routing protocol with the proposed adjustment method can efficiently reduce and balance energy consumption. Furthermore, the key metric of delivery ratio is improved compared with the original n-Epidemic routing protocol. Obviously the proposed scheme prolongs the network life time because of the equilibrium of energy consumption among nodes.

Effect of dietary copper level on the gut microbiota and its correlation with serum inflammatory cytokines in Sprague-Dawley rats

Feng Zhang,Weijiang Zheng,Rong Guo,Wen Yao 한국미생물학회 2017 The journal of microbiology Vol.55 No.9

In China’s swine industry, copper is generally supplemented above the National Research Council (NRC) requirement (2012) because of its antimicrobial properties and the potential for growth promotion. Yet few are concerned about whether this excess supplementation is necessary. In this study, the 16S rRNA pyrosequencing was designed and used to investigate the effect of dietary copper level on the diversity of the fecal microbial community and the correlation of copper level with the serum level of inflammatory cytokines in Sprague-Dawley rat models. The results showed that the diet containing a high level of Cu (120 and 240 mg/kg) changed the microbial richness and diversity of rat feces associated with the increased copper content in the rat ileac and colonic digesta. Furthermore, a Pearson’s correlation analysis indicated that an accumulation of unabsorbed copper in the chyme was correlated with the microbial composition of the rat feces, which was linked with TNF-α in serum. The results suggest that dietary copper level may have a direct impact on circulating inflammatory cytokines in the serum, perhaps inducing an inflammatory response by altering the microbial composition of rat feces. Serum TNF-α could be the chief responder to excessive copper exposure.

Single-pass capacitive deionization with a HNO₃-modified electrode for fluoride removal

Feng Zhang,Fan Yang 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.1

HNO₃-modified activated carbon was used to make electrodes for single-pass capacitive deionization for removing F<SUP>-</SUP> from drinking water. The optimal operating conditions for F¯ removal were studied, and the F¯ removal performance, cycle stability, and charge efficiency of the electrode were investigated. Based on these results, an optimization scheme was proposed for practical applications. After HNO₃ modification, the proportion of micropores, specific surface area, and number of oxygen-containing functional groups on the activated-carbon surface increased, resulting in a significant increase in the specific capacitance of the electrode. Under optimal operating conditions, the adsorption capacity of the modified electrode was 13% higher than that of the unmodified electrode, while the charge efficiency increased by 25% and reached a peak value after about 1,100 s. The HNO₃-modified electrode had good cycle stability, and maintained 83% of the original adsorption capacity after 5 cycles. Optimizing the adsorption time (1,500 s) and desorption time (900 s), 80% of the specific adsorption capacity was maintained after 5 cycles. In addition, the cycle time was reduced by 32%, and the utilization rate of electric-double-layer adsorption sites was optimized, resulting in a reduction in the energy consumption per unit F¯ removal.

Microstructure and quality of SiC foam filters for casting

Fengzhang Ren,Gangjun Zhai,Zhanhong Ma,Xiaobo Chen,Alex A. Volinsky 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.6

Maximum compressive strain at high temperature was introduced as a new quality indicator of ceramic foam filters used in metal casting. Maximum compressive strain at high temperature, number of thermal cycles before failure, room temperature compressive strength and bulk density of SiC-based ceramic foam filters with the same pore size produced by four manufacturers were measured. The best quality product exhibited the highest number of thermal cycles before failure and minimum strain at high temperature. Differences in properties were elucidated based on X-ray diffraction and scanning electron microscope microstructural characterization. The best quality filter has less glass phase and more quartz phase, while lower quality filters have more glass and cristobalite phases. The glass phase increases the maximum strain at high temperature, while both glass and cristobalite phases reduce the number of thermal cycles before failure. The maximum compressive strain at high temperature can be utilized as the main indicator for evaluating the quality of ceramic foam filters.

Recoating slurry process effects on the SiC-based casting foam filter properties

Fengzhang Ren,Gangjun Zhai,Zhanhong Ma,Alex A. Volinsky,Baohong Tian 한양대학교 세라믹연구소 2014 Journal of Ceramic Processing Research Vol.15 No.2

Polyurethane foam was used as a precursor for fabricating SiC-based ceramic foam filters. Two recoating slurry processes were adopted to enhance the strength of ceramic foam. One was the recoating slurry of stoved green body and another was the recoating slurry of pre-sintered green body. The differences in weight increase and thermal shock resistance of ceramic foams fabricated by the two recoating slurry processes were investigated. The effects of pre-sintering temperature on weight increase and thermal shock resistance are discussed. Thermal shock resistance of ceramic foams fabricated by two recoating slurry processes is lower than that by the single coating slurry process. Compared with recoating slurry of pre-sintered green bodies, with the same slurry, the weight increase of ceramic foams fabricated by recoating slurry of the stoved green bodies is less, but the number of thermal cycles to failure is much higher. For ceramic foams fabricated by recoating slurry of presintered green bodies with the same slurry, the weight increase and the number of thermal cycles to failure decreased with the pre-sintering temperature.