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Passivity Bilateral Teleoperatio System with Time Delay
Changlei Zhang(장창레이),Kil-to Chong(정길도) 대한전기학회 2006 대한전기학회 학술대회 논문집 Vol.2006 No.10
This paper presents a force-reflecting teleoperation scheme with time delay. In reciprocal systems, to improve the stability and performance of the tleleoperation system, the network provides a wide bandwidth, no congestion. However, as use of Internet increases, congestion situation of network increased and transmission time and packet loss increased accordingly. This can make system unstable at remote control. In this paper, we present a passive control scheme for a force reflecting bilateral teleoperation system via the Internet and we investigated how a varying time delay affects the stability of a teleoperation system. A new approach based on a passive control scheme was designed for the system. The simulation results and the tracking performance of the implemented system are presented in this paper.
Wu Zhang,Changlei Lv,Weixiong Liu,Xinqian Zhang,Feiyan Han 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.4
This study describes a method for establishing the model of a circular arc wire rope with special-shaped cross sections, such as oval or triangular, derives the mathematical model for these wire ropes and establishes a three-dimensional (3D) model of one-twelfth circle for them. The wire rope modeling system has been enhanced. The traditional method for drawing the 3D model of the wire rope is to input the wire central line equation into the drawing software (for example, Pro/E) and then sweep, which is tedious and time-consuming. To address this issue, this study develops a software that enables the rapid establishment of a 3D model of steel wire rope by inputting key steel wire rope parameters. Moreover, this software streamlines the wire rope modeling process, increases the wire rope’s design efficiency, and introduces a new method for wire rope modeling.
Phenol removal via activated carbon from co-pyrolysis of waste coal tar pitch and vinasse
Ming Gao,Xiaona Wang,Changlei Xia,Na Song,Yuhui Ma,Qunhui Wang,Tianxue Yang,Shengbo Ge,Chuanfu Wu,Su Shiung Lam 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.1
The behavior and characteristics of phenol adsorption by activated carbon produced from co-pyrolysis of coal tar pitch and vinasse were investigated. Coal tar pitch and vinasse (mass ratio of 1 : 3) were firstly co-pyrolyzed and carbonated at 400 oC for 2 h. The carbonized material produced was then soaked with saturated KOH solution and activated at 800 oC for 1 h to form activated carbon. Results from the phenol wastewater adsorption experiments suggest that pseudo-second-order kinetics and the Weber-Morris model could reflect the time-dependent adsorption behavior of phenol wastewater by the activated carbon, revealing that internal diffusion represents the rate-limiting procedure and dominant process to control the adsorption rate in the early stage of the adsorption. Monolayer adsorption played the key role during the phenol adsorption. The adsorption was an endothermic reaction in temperature ranging from 15 oC to 35 oC, indicating that the adsorption speed could be stimulated by the increasing temperature. This study establishes a theoretical foundation for the usage and the potential application of the activated carbon derived from coal tar pitch and vinasse in wastewater treatment.
Characterization of Key Enzymes for D-lactic Acid Synthesis in Leuconostoc citreum KM20
Jinxi Liu,Hongjie Piao,Changlei Liu,Guanyang Li,Hushan Cui,Qing Jin 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.6
Leuconostoc citreum is a heterofermentative lactic acid bacteria, which converts pyruvate to D-lactic acid using D-lactate dehydrogenase. For analyzing the characteristics of the key enzyme for D-lactic acid synthesis in Leuconostoc citreum KM20, the key gene of D-lactic acid synthesis was identified by genomics and transcriptomic analysis, which was cloned into the vector pET-15b and transformed into Escherichia coli BL21 (DE3). The D-lactate dehydrogenase was purified by Ni- NTA column affinity chromatography and its enzymatic property was studied. The results showed that LCK_00389 gene was the key gene among the seven genes related to lactic acid synthesis. The molecular mass of the enzyme encoded by LCK_00389 was 38.8 kDa; the specific activity was 272.71 U/mg; the optimum pH and temperature for pyruvate reduction were 8.0 and 20oC, those for lactate oxidation were 12.0 and 30oC, respectively; the Km and the kcat value of pyruvate were 0.24 ± 0.01 mmol/L and 165.99 ± 3.65 s-1, those of D-lactic acid were 33.27 ± 2.72 mmol/L and 14.67 ± 0.29 s-1; Ca2+, Cu2+ and Na+ promoted the activity of the enzyme, while Zn2+ and Sodium dodecyl sulfate (SDS) inhibited the activity of the enzyme; in addition to using pyruvate as substrate, it also had had strong catalytic activity for oxaloacetate, phenylpyruvate and 2-ketoglutarate.
Jian Xu,Yewen Cao,Deqiang Wang,Changlei Wu,Guang Yang 한국전자통신연구원 2016 ETRI Journal Vol.38 No.3
Recently, a product-matrix (PM) framework was proposed to construct optimal regenerating codes for homogeneous distributed storage systems (DSSs). In this paper, we propose an extended PM (EPM) framework for coding of heterogeneous DSSs having different repair bandwidths but identical storage capacities. Based on the EPM framework, an explicit construction of minimum remote-repair bandwidth regenerating (MRBR) codes is presented for a specific heterogeneous DSS, where two geographically different datacenters with associated storage nodes are deployed. The data reconstruction and regeneration properties of the MRBR code are proved strictly. For the purpose of demonstration, an example implementation of MRBR code is provided. The presented MRBR code is the first optimal strict-regenerating code for heterogeneous DSSs. In addition, our proposed EPM framework can be applied to homogeneous systems also.
Collaborative Sub-channel Allocation with Power Control in Small Cell Networks
( Guang Yang ),( Yewen Cao ),( Deqiang Wang ),( Jian Xu ),( Changlei Wu ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.2
For enhancing the coverage of wireless networks and increasing the spectrum efficiency, small cell networks (SCNs) are considered to be one of the most prospective schemes. Most of the existing literature on resource allocation among non-cooperative small cell base stations (SBSs) has widely drawn close attention and there are only a small number of the cooperative ideas in SCNs. Based on the motivation, we further investigate the cooperative approach, which is formulated as a coalition formation game with power control algorithm (CFG-PC). First, we formulate the downlink sub-channel resource allocation problem in an SCN as a coalition formation game. Pareto order and utilitarian order are applied to form coalitions respectively. Second, to achieve more availability and efficiency power assignment, we expand and solve the power control using particle swarm optimization (PSO). Finally, with our proposed algorithm, each SBS can cooperatively work and eventually converge to a stable SBS partition. As far as the transmit rate of per SBS and the system rate are concerned respectively, simulation results indicate that our proposed CFG-PC has a significant advantage, relative to a classical coalition formation algorithm and the non-cooperative case.
Evaluation on direct aqueous carbonation of industrial/mining solid wastes for CO2 mineralization
Zijian Li,Jie Chen,Zongze Lv,Yichao Tong,Jingyu Ran,Changlei Qin 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-
Carbonation of industrial alkaline resources can achieve dual effects of CO2 sequestration and solid wastemanagement, and the carbonated product may act as a potential cementitious backfill material. Based onthis idea, CO2 mineralization characteristics and potential of typical industrial solid wastes, mine tailingsand their mixtures are investigated by direct aqueous carbonation, and effects of reaction parameters,including particle size, reaction temperature, solid-to-liquid ratio, CO2 concentration, are systematicallyexplored. Results show that industrial solid wastes with a high Ca content such as carbide slag have bettercarbonation activity with the maximum CO2 sequestration capacity of 544.6 g-CO2/kg, while the carbonationof mine tailings is very weak. The combination of coal fly ash with tailings has a potentialstimulative effect during carbonation. Moreover, influences of carbonation parameters are revealed inthis study, and optimal reaction parameters are determined to be particle size below 75 lm, temperatureof 60 C, solid-to-liquid ratio of 100 g/L, and CO2 concentration of 15% within mild range. These resultscan provide fundamental knowledge for the integrated CO2 mineralization and goaf backfilling, andaccelerate carbon reduction and waste resource utilization.