A combined approach to evaluate activity and structure of soil microbial community in long-term heavy metals contaminated soils

Tianqi Wang,Zhimin Yuan,Jun Yao 대한환경공학회 2018 Environmental Engineering Research Vol.23 No.1

In the present study, long-term heavy metals (HMs) contaminated soil samples from a well-known Pb/Zn smelting area in the southwest of China were collected, and physicochemical and biological characteristics of these samples were evaluated. Soil samples contained different concentrations of HMs, namely Pb, Zn, Cu, and Cd. Enzyme activity analyses combined with microcalorimetric analysis were used for soil microbial activity evaluation. Results showed that two soil samples, containing almost the highest concentrations of HMs, also shared the greatest microbial activities. Based on correlation coefficient analysis, high microbial activity in heavily HMs contaminated soil might be due to the high contents of soil organic matter and available phosphorus in these samples. High-throughput sequencing technique was used for microbial community structure analysis. High abundance of genera Sphingomonas and Thiobacillus were also observed in these two heavily contaminated soils, suggesting that bacteria belonging to these two genera might be further isolated from these contaminated soils and applied for future studies of HMs remediation. Results of present study would contribute to the evaluation of microbial communities and isolation of microbial resources to remediate HMs pollution.

Improved Reinforcement Learning through Imitation Learning Pretraining Towards Image-based Autonomous Driving

Tianqi Wang,Dong Eui Chang 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

We present a training pipeline for the autonomous driving task given the current camera image and vehicle speed as the input to produce the throttle, brake, and steering control output. The simulator Airsim’s [1] convenient weather and lighting API provides a sufficient diversity during training which can be very helpful to increase the trained policy’s robustness. In order to not limit the possible policy’s performance, we use a continuous and deterministic control policy setting. We utilize ResNet-34 [2] as our actor and critic networks with some slight changes in the fully connected layers. Considering human’s mastery of this task and the high-complexity nature of this task, we first use imitation learning to mimic the given human policy and then leverage the trained policy and its weights to the reinforcement learning phase for which we use DDPG [3]. This combination shows a considerable performance boost comparing to both pure imitation learning and pure DDPG for the autonomous driving task.

Neural Network Based Terminal Iterative Learning Control for Tracking Run-Varying ReferencePoint With Initial State Variance

Tianqi Liu,Danwei Wang,Ronghu Chi 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

In this paper, a neural network based terminal iterative learning control(NNTILC) method is proposed for a class of discrete time uncertain linear systems to track run-varying reference point The zero error initial condition in most of the previous work on terminal iterative learning control(TILC) is removed by the use of neural network. A radial basis function (RBF) neural network is developed to approximate the effect of initial state and reference on terminal output iteratively. By involving these information as well as the reference signal in the control scheme, the proposed NNTILC can drive the system to track run-varying reference point fast and precisely beyond the initial state variance and reference change. Stability and convergence of this approach are proved and computer simulation results are provided to confirm its effectiveness further.

Longitudinal Dynamic End Effect of Single-Sided Linear Induction Motor for Medium–Low Speed Maglev

Wang Ying,Liu Xuelong,Lu Weiguo,Wen Tianqi,Yu Fan,Wu Qian 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4

The Short Primary Single-sided Linear Induction Motor (SLIM) applied in medium–low maglev vehicle has end eff ect that will cause a signifi cant reduction of train thrust. This paper analyzes the relationship between the Longitudinal Dynamic End Eff ect (LDEE) and the speed of SLIM. It is concluded that LDEE increases with the motor speed. The LDEE at motor’s exit area is called tailing eff ect. We take advantage of the tailing eff ect between adjacent SLIMs to make the air-gap magnetic fi eld of these motors continuous by adjusting their intervals and excitation phase diff erence. The several SLIM on the same side of the vehicle is equivalent to a “whole motor” with overall one entry area and one exit area. This method can reduce the resistance of the whole vehicle running at high speed, which can provide a new solution for the design of high-speed SLIM applied in Maglev

Wireless capsule endoscopy Locomotion

Wang, Zhao,Lim, Eng Gee,Leach, Mark,Xia, Tianqi,Lee, Sanghyuk Convergence Society for SMB 2014 융합정보논문지 Vol.4 No.1

무선 캡슐 내시경 (WCE)은 세기 초에 개발 될 수 있는 가장 영향력 있는 바이오 의료 전자 기술 중 하나였다. 기존의 내시경 진단과 비교하여,이 응용 프로그램은 이에 훨씬 더 사용자 친화적인 방식으로 전체 위장관 (GI) 트랙을 검사하기 위한 새로운 대안을 가진 외과 의사를 제공하는 비 침습 및 저 위험이 특징이다. 그 이외에도 일반 하드웨어 업그레이드에서 WCE 연구의 국경은 기본적으로 캡슐의 소형화 및 활성화 운동에 있다. 운동은 일반적으로 자연적인 연동 운동의 함수이다 현재 상용화 WCE 제품의 본질적인 결점을 극복하기 위해, 활성 운동력 효과적으로 다른 장기에 장치를 탐색 대상으로 인간 내 치료 기능을 수행하기 위해 사용되는 전략의 시리즈로서 제안 조직과 연구의 측면에 대한 몇 가지 새로운 디자인의 리뷰는 이 문서에서 논의 될 것이다. Wireless capsule endoscopy (WCE) was one of the most influential bio-medical electronic technologies to be developed at the beginning of the century. In comparison to traditional endoscopic diagnosis, this application is characterized as non-invasive and low-risk, thereby providing surgeons with a new alternative for inspecting the entire gastrointestinal (GI) track in a much more user friendly way. Apart from regular hardware upgrades, the frontier of WCE research basically lies in the miniaturization of the capsule and in active locomotion. In order to overcome the intrinsic drawback of current commercialized WCE products, which is that locomotion is generally a function of natural peristalsis, active locomotion is proposed as a series of strategies used to effectively navigate the device into different organs and conduct therapeutic functions within targeted human tissues. Reviews of several novel designs with respect to this aspect of research will be discussed in this article.

Analysis of Mechanical Characteristics of Steel-Concrete Composite Flat Link Slab on Simply-Supported Beam Bridge

Chengquan Wang,Yonggang Shen,Yun Zou,Yizhou Zhuang,Tianqi Li 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.8

Based on linear elastic theory, the concrete cracking problem of link slab on simply supported beam bridge was explored and theoretical analysis of bridge link slabs were carried out. Meanwhile, the formulas for calculating the stress of link slab were deduced and the cause for continuous damage of bridge deck was quantitatively analyzed. On the base of analysis of its failure mechanism, a new type of steel-concrete composite flat link slab was proposed. The results of full-scale model tests and finite element (FE) analysis indicated that it can alter the transfer path of internal forced inside the link slab and then concrete cracking can be prevented effectively. It was found that the main factors to link slab failure were influentially descending from girder end upturning, longitudinal tensile action and girder end rotation. Furthermore, the unbonded region between girder and link slab can effectively decrease the continuous stress and then alleviate the damage to bridge deck. All those results in this paper can be used as a reference and guidance for further research and development of new type of bridge link slab and jointless bridge.

Experimental Study on Mechanical Properties of Q690 High Strength Steel in Marine Corrosive Environment

Hongchao Guo,Tianqi Lei,Jinguang Yu,Defa Wang,Xiaolei Li 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.2

In order to study the mechanical property degradation rule of Q690 high-strength steel in the ocean wave splash area, the rusted specimen is obtained by indoor damp heat surrounding soaking environment corrosion test. The scanning electron microscopy, uniaxial tensile and cyclic loading tests of corroded steel are performed. This paper analyzes the steel from elastic modulus, yield strength, ductility and law of hysteresis degradation under diff erent corrosion cycles and establishes the constitutive model of HSS. The results show that the appearance of HSS is obviously aff ected by the corrosion cycle. With the increase of the corrosion cycle, reddish-brown fl aky corrosion products are formed on the surface of the steel and there are obvious corrosion pits. After 100 days of corrosion, the corrosion rate of steel reached 7.21%; the elastic modulus and yield strength under uniaxial tension load decreased by 10.2% and 4.9%. Under the eff ect of cyclic reciprocating load, the hysteretic energy is reduced by 15.3%; at the same time, the test curve is fi tted by the secondary plastic fl ow model and the Ramberg–Osgood model and it is found that the shape parameter S 1 and the cyclic strengthening coeffi cient K’ are reduced by 20.1% and 10.2%, While the shape parameter S 2 and the cycle strengthening index n’ have no obvious changes.

Laser Vision-Based Automatic Trajectory Planning Technology for Spatial Intersecting Joint Weld

Zhenwei Jia,Tianqi Wang,Liangyu Li,Junjie He 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.1

This paper studies the laser vision-based automatic trajectory planning technology for spatial intersecting joint weld. Firstly, the mathematical model of T-type off-axis non-groove intersecting joint is established, and the welding seam characteristics of the intersecting joint are analyzed. Secondly, a triangular pseudo-rotation feature pixel detection algorithm based on monocular structured light vision is proposed to realize the rapid extraction and location of spatial intersecting joint weld. Then, a laser vision-based calibration method for the workpiece coordinate system of the T-type intersecting joint is proposed, the relationship between intersecting joint workpiece coordinate system and robot base coordinate system is established, and the trajectory equation is obtained. At last, a searching discrete of chord error interpolation control algorithm is proposed to automatically discrete and plan welding torch gesture data. Experiments show that the technology can achieve higher precision location and better intersecting joint weld trajectory planning, and realize high-quality automatic weld of intersecting joint.

Commutability Assessment of Candidate External Quality Assessment Materials for Aminotransferase Activity Measurements Based on Different Approaches in China

Long Qichen,Qi Tianqi,Zhang Tianjiao,Wang Jing,Zeng Jie,Ying Yan,Meng Wang,Wei Huang,Haijian Zhao,Wenxiang Chen,Chuanbao Zhang 대한진단검사의학회 2021 Annals of Laboratory Medicine Vol.41 No.1

Background: Using commutable external quality assessment (EQA) materials is important for monitoring successful harmonization efforts. We assessed the commutability of four human serum pool (HSP) preparations to identify candidate EQA materials for alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity measurement. Methods: One set each of 85 clinical samples (CSs) was collected for ALT and AST activity measurement. The 15 candidate EQA materials included four types of HSP preparations (A to D): materials A, C, and D contained human original recombinant (HOR) aminotransferases; materials B was mixed leftover samples. The CSs and 15 candidate EQA materials were analyzed using seven routine assays, and the ln-transformed results were analyzed in 21 assay pairs. Commutability was assessed using Deming regression, with a 95% prediction interval (CLSI approach) and the difference in bias with an error component model (International Federation of Clinical Chemistry and Laboratory Medicine [IFCC] approach). Results: For ALT, all materials were commutable for 14–21 assay pairs according to the CLSI and IFCC approaches. For AST, B01-03 showed commutability for 14-21 assay pairs, and C01-03 and D01-03 showed commutability for no less than 10 assay pairs according to the two approaches. A01-06 were commutable for 9-16 assay pairs according to the CLSI approach, but for 6-9 assay pairs according to the IFCC approach. Conclusions: Mixed leftover samples showed desirable commutability characteristics as candidate EQA materials for routine aminotransferase activity measurements. Human serum bases supplemented with HOR were commutable for most routine ALT activity measurements.

Analysis of the Bacterial Community in a Full-scale Printing and Dyeing Wastewater Treatment System Based on T-RFLP and 454 Pyrosequencing

Qingxiang Yang,Jia Wang,Xinkuan Han,Yuanyuan Xu,Dong Liu,Hongxin Hao,Xuemei L,Yuhui Guo,Tianqi Niu,Shiyue Qi 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.1

In this study, the bacterial dynamics andstructure compositions in the two-stage biological processof a full-scale printing and dyeing wastewater (PDW)treatment system were traced and analyzed by terminalrestriction fragment length polymorphism (T-RFLP) and454 pyrosequencing techniques. T-RFLP analysis showedthat the microbial communities experienced significantvariation in the process of seed sludge adaptation to thePDW environments and were in constant evolution duringthe whole running period of the system, despite theconstant COD and color removal effects. Pyrosequencingresults indicated that the two-stage biological systemharbored rather diverse bacteria, with Proteobacteria beingthe predominant phylum during the steady running period,although its microbial compositions differed. The firststageaerobic tank was dominated by α-Proteobacteria(89.05% of Proteobacteria), whereas in the second-stageaerobic tank, β- and γ-Proteobacteria, besides α-Proteobacteria,were the dominant bacterial populations.