Dynamic Analysis of Slab Track with Crack Considering Rail Corrugation

Jianwei Yang,Peishan Liu,Xiaohui Wang,Yue Zhao,Fu Liu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.12

To investigate the dynamic response of ballastless slab track with crack in the rail corrugation area under the load of urban rail vehicle, this study establishes a vertical coupling dynamic model of the vehicle-rail-slab track, considering crack and rail corrugation. The exact closed-form solution of the vibration mode of the Euler Bernoulli beam with crack is introduced. Furthermore, a finite element model of the slab track is developed, and the vertical dynamic model's fastening force is applied to the slab track at the rail corrugation frequency to calculate the surface compressive stress of the slab track. The results indicate that, under rail corrugation conditions of varying magnitudes, the presence of crack induces higher vertical acceleration amplitudes in the slab track at low frequencies. As the wave depth increases, the acceleration of the slab track at the crack gradually intensifies. Moreover, with an increasing wavelength, the corresponding frequency to the acceleration amplitude of the slab track at the crack gradually decreases. Notably, when the wave depth is 0.2 mm and the wavelength is 50 mm, the axle load transfer rate exhibits the greatest increase. These research findings offer valuable insights for the maintenance of urban rail transit slab track systems.

Nondestructive Early Detection of Bruising in Pear Fruit Using Optical Coherence Tomography

Yang Zhou,Jianwei Mao,Di Wu,Tiebing Liu,Yun Zhao,Wujie Zhou,Zhengwei Chen,Fangni Chen 한국원예학회 2019 원예과학기술지 Vol.37 No.1

Pear fruit is susceptible to mechanical injury during harvesting, packaging, and transportation. Optical coherence tomography (OCT) can provide information concerning chemical and microstructural changes of fruit tissues. Therefore, using OCT to evaluate fruit quality is of great significance. In this study, OCT was used for early detection of subtle bruise symptoms underneath the pear peel. First, the signal intensity versus depth in relation to the OCT images of fruit tissue was determined, which was derived from the values of the OCT signal slope (OCTSS) and 1/e light penetration depth (D1/e). Furthermore, shaping (α) and scaling (β) indices were estimated by fitting a gamma distribution function to the signal intensity profile. After mechanical injury, OCTSS, α, and β decreased and the D1/e value increased. Distribution analysis of the relationship between α versus β served as an effective method to identify tissue bruising at an early stage. In conclusion, the results suggest that OCTSS, D<SUB>1/e</SUB>, and the α versus β distribution are closely correlated with bruise injury in pear fruit tissues. Thus, OCT is a promising technology for early and nondestructive bruise detection.

Scheduling Analysis of Failure-aware VM in Cloud System

Yang Cao,CheulWoo Ro,JianWei Yin 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.1

Effects of Channel Selection and Observation Error Allocation on the Assimilation of AIRS Data

Jianwei Zhang,Gen Wang,Yin Yang,Delegerima,Jin Wang 보안공학연구지원센터(IJSIP) 2012 International Journal of Signal Processing, Image Vol.5 No.4

Study on Hyper-spectral Atmospheric Infrared Sounder Assimilation

Jianwei Zhang,Gen Wang,Yin Yang,Xia Zhong,Jin Wang 보안공학연구지원센터 2013 International Journal of Hybrid Information Techno Vol.6 No.1

Adaptive Decentralized Event-triggered Tracking Control for Large-scale Strongly Interconnected Nonlinear System with Global Performance

Wenjing Yang,Jianwei Xia,Xiaoxiao Guo,Miao Yu,Na Zhang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.5

In this paper, an adaptive decentralized event-triggered global performance control of a class of largescale strongly interconnected nonlinear systems with external disturbances is investigated. Firstly, the original performance constrained large-scale nonlinear system is transformed into an equivalent unconstrained nonlinear largescale system by barrier function transformation. Secondly, the additional assumptions of interconnect terms such as upper bound function and matching conditions are eliminated by using the inherent properties of Gaussian function. In addition, an event-triggered mechanism is designed to reduce unnecessary transfers between the controller and the actuator for better resource efficiency. It is shown that the proposed control schemes guarantee that all signals of the closed-loop system are bounded, and the output tracking error is always kept within the given boundary. Finally, a numerical system and a mass-spring damping system are taken as examples to verify the effectiveness of the proposed control method.

Nomogram for Predicting Central Lymph Node Metastasis in Papillary Thyroid Cancer: A Retrospective Cohort Study of Two Clinical Centers

Zheyu Yang,Yu Heng,Jianwei Lin,Chenghao Lu,Dingye Yu,Lei Tao,Wei Cai 대한암학회 2020 Cancer Research and Treatment Vol.52 No.4

Purpose Central lymph node metastasis (CNM) are highly prevalent but hard to detect preoperatively in papillary thyroid carcinoma (PTC) patients, while the significance of prophylactic compartment central lymph node dissection (CLND) remains controversial as a treatment option. We aim to establish a nomogram assessing risks of CNM in PTC patients, and explore whether prophylactic CLND should be recommended. Materials and Methods One thousand four hundred thirty-eight patients from two clinical centers that underwent thyroidectomy with CLND for PTC within the period 2016-2019 were retrospectively analyzed. Univariate and multivariate analysis were performed to examine risk factors associated with CNM. A nomogram for predicting CNM was established, thereafter internally and externally validated. Results Seven variables were found to be significantly associated with CNM and were used to construct the model. These were as follows: thyroid capsular invasion, multifocality, creatinine > 70 μmol/L, age < 40, tumor size > 1 cm, body mass index < 22, and carcinoembryonic antigen > 1 ng/mL. The nomogram had good discrimination with a concordance index of 0.854 (95% confidence interval [CI], 0.843 to 0.867), supported by an external validation point estimate of 0.825 (95% CI, 0.793 to 0.857). A decision curve analysis was made to evaluate nomogram and ultrasonography for predicting CNM. Conclusion A validated nomogram utilizing readily available preoperative variables was developed to predict the probability of central lymph node metastases in patients presenting with PTC. This nomogram may help surgeons make appropriate surgical decisions in the management of PTC, especially in terms of whether prophylactic CLND is warranted.

Fault-tolerant Consensus of Leader-following Multi-agent Systems Based on Distributed Fault Estimation Observer

Pu Yang,Ben Ma,Yan Dong,Jianwei Liu 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.5

This paper is concerned with the fault-tolerant consensus control problem for leader-following multiagent systems with actuator faults and external disturbance. Firstly, by employing the relative output estimation errors with respect to the corresponding neighbours and the leader, a distributed fault estimation observer is constructed for each follower and the established global estimation error system is proven to be asymptotically stable. Secondly, based on the obtained fault estimation, the active fault-tolerant consensus control protocol for each follower is proposed with the utilization of the relative output measurements rather than the state of the systems. Under this control protocol, the actuator faults can be compensated and the influence of disturbance can be eliminated as well. Moreover, it is worth noticing that the process of designing the fault estimation observer and the fault-tolerant controller is separated and their performances are considered simultaneously to simplify the design procedures. Finally, an illustrative example is presented to demonstrate the applicability and the effectiveness of the obtained results.

Prediction of Pharmacokinetics and Penetration of Moxifloxacin in Human with Intra-Abdominal Infection Based on Extrapolated PBPK Model

LiQin Zhu,JianWei Yang,Yuan Zhang,YongMing Wang,JianLei Zhang,YuanYuan Zhao,WeiLin Dong 대한약리학회 2015 The Korean Journal of Physiology & Pharmacology Vol.19 No.2

The aim of this study is to develop a physiologically based pharmacokinetic (PBPK) model in intraabdominalinfected rats, and extrapolate it to human to predict moxifloxacin pharmacokinetics profilesin various tissues in intra-abdominal infected human. 12 male rats with intra- abdominal infections,induced by Escherichia coli, received a single dose of 40 mg/kg body weight of moxifloxacin. Bloodplasma was collected at 5, 10, 20, 30, 60, 120, 240, 480, 1440 min after drug injection. A PBPK modelwas developed in rats and extrapolated to human using GastroPlus software. The predictions wereassessed by comparing predictions and observations. In the plasma concentration versus time profileof moxifloxcinin rats, Cmax was 11.151 μg/mL at 5 min after the intravenous injection and t1/2 was2.936 h. Plasma concentration and kinetics in human were predicted and compared with observed datas. Moxifloxacin penetrated and accumulated with high concentrations in redmarrow, lung, skin, heart,liver, kidney, spleen, muscle tissues in human with intra-abdominal infection. The predicted tissue toplasma concentration ratios in abdominal viscera were between 1.1 and 2.2. When rat plasma concentrationswere known, extrapolation of a PBPK model was a method to predict drug pharmacokineticsand penetration in human. Moxifloxacin has a good penetration into liver, kidney, spleen, as well asother tissues in intra-abdominal infected human. Close monitoring are necessary when using moxifloxacindue to its high concentration distribution. This pathological model extrapolation may provide referenceto the PK/PD study of antibacterial agents.

Effect on tower crane structural vibration under the lifting-luffing coupling condition

Fu Liu,Jianwei Yang,Jinhai Wang,Changdong Liu,Xiaohui Wang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.10

The present research aims to investigate parametrically the structural vibration analysis of tower crane under the lifting-luffing coupling condition. Structural vibration greatly affects tower crane stability. The structural dynamics of a crane should be considered for studying motion behavior and vibration feature. The dynamic model of the tower crane is presented based on air resistance, boom deflection, and Lagrange equation under the lifting-luffing coupling condition. The vibration model of the tower crane was validated by an experiment. The experiment was conducted with an accelerating speed until reaching the constant speed and then with decelerating speed. This study analyses structural parameters to acquire the dynamic characteristics and vibration features of the tower crane under the compound working condition. The vibration responses of the mast and the boom are studied with frequency- and timedomain indicators. Results show that payload mass, luffing acceleration, boom length, mast height, and girder length significantly influence the mast vibration. In comparison, payload mass, trolley acceleration, and boom length affect the boom vibration. This research can improve the design of a dynamic system for tower crane safety.