Performance Evaluation Model of Logistics Enterprises Considering Mass Data in the Internet of Things

Jun Qi,Lan Yi 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.4

In allusion to such problems as the no use of the structural information of the dataset in the traditional clustering effectiveness evaluation function and the excessive noisy point deletion, the research method integrating theoretical analysis and empirical analysis is adopted to establish KPI management index system model for telecommunication enterprises. A new clustering effectiveness evaluation function is proposed in this article. Specifically, PCA (principal component analysis) method in multivariate statistics is applied in the performance evaluation systems of telecommunication enterprises, and meanwhile relevant instances are analyzed and evaluated. Therein, the evaluation index system has the features of simpleness, strong practicability, low operation cost and high accuracy, and the geometric structure features of dataset are added for the performance evaluation of telecommunication enterprises. Additionally, distance critical value L is added in the compact indexes and the constraint condition thereof is also given in order to construct a new clustering effectiveness evaluation index model which can more scientifically and rationally reflect the actual evaluation result.

Bio-inspired micro/mini propulsion at air-water interface: A review

Junqi Yuan,Sung Kwon Cho 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.12

This paper reviews and discusses the propulsion of water-floating natural creatures and man-made devices at the air-water interface. Natural creatures with a large ratio of body weight to surface tension force normally propel themselves by repeatedly slapping and stroking their feet while natural creatures with a small ratio of body weight to surface tension force are floated dominantly by surface tension and are propelled by various propulsion mechanisms. Some animals developed unique walking and propelling methods such as leaping,sailing, meniscus climbing, and utilizing of Marangoni effect. Inspired by the natural creatures, a large number of water walking robots and propulsion methods have been developed. Many of them are based on the walking and propelling of water striders, although they require complicated fabrication and structures. Some of the recently developed devices are propelled by the gradient of surface tension (via addition of heat or surfactant) or by streaming flows (induced from oscillations of bubbles or interfaces). These methods need relatively simple mechanical structures and fabrication but are effective only in limited conditions. The bio-inspired water floating and propelling systems can be applied to environment monitoring systems, surveillance security systems, educational robots, and toys. In particular,this paper suggests applying those systems to “smart dust” sensory robots and pollutant collecting devices.

Robust Sliding-mode Observer-based Sensor Fault Estimation, Actuator Fault Detection and Isolation for Uncertain Nonlinear Systems

Junqi Yang,Fanglai Zhu,Xin Wang,Xuhui Bu 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.5

This paper deals with the issues of sensor fault estimation, actuator fault detection and isolation for a class of uncertain nonlinear systems. By taking the sensor fault vector as a part of an extended state vector, the original system with sensor faults, actuator faults and unknown inputs is transformed into an augmented singular system which is just with actuator faults and unknown inputs. For the constructed singular system, a robust sliding-mode observer is developed to simultaneously estimate the states and sensor faults of original system, and the observer gain matrices are computed in terms of linear matrix inequalities by solving an optimization problem. Then an actuator fault detector is designed to detect actuator faults when ones occur, and multiple observers used as actuator fault isolators are proposed to identify which actuator is with fault. Finally, a simulation example is given to illustrate the effectiveness of the proposed methods.

Sliding-mode Observers for Nonlinear Systems with Unknown Inputs and Measurement Noise

Junqi Yang,Fanglai Zhu,Wei Zhang 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.5

This paper deals with the design of observers for Lipschitz nonlinear systems with not only unknown inputs but also measurement noise when the observer matching condition is not satisfied. First, an augmented vector is introduced to construct an augmented system, and an auxiliary output vector is constructed such that the observer matching condition is satisfied and then a high-gain sliding mode observer is considered to get the exact estimates of both the auxiliary outputs and their derivatives in a finite time. Second, for nonlinear system with both unknown inputs and measurement noise, an adaptive robust sliding mode observer is developed to asymptotically estimate the system’s states, and then an unknown input and measurement noise reconstruction method is proposed. Finally, a numerical simulation example is given to illustrate the effectiveness of the proposed methods.

Multiple-mode Adaptive State Estimator for Nonlinear Switched Systems

Junqi Yang,Yantao Chen,Lizhi Cui 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.4

This paper deals with the issue of state estimator design for nonlinear switched systems. A multiplemodeadaptive estimator is proposed under mode-dependent average dwell time (MDADT) switching, and theswitching signal with MDADT constraint is also obtained to guarantee the exponential stability of estimation errordynamics, where the Lipschitz constant may be unknown since it is adaptively adjusted by designing an adaptationlaw. Based on both Lyapunov stable theory and the feasible solution of an optimization problem with linear matrixinequality constraint, the gain matrices and switching signals are provided, respectively. The sufficient conditionsof the existence of multiple-mode adaptive switched estimator are also derived. Meanwhile, the above methodsare also extended to the case of the average dwell time (ADT) switching, and an algorithm is given to summarizethe implementation of the proposed estimators. Finally, the effectiveness of the designed methods is illustrated bysimulation examples.

An uncertainty representation based sampling method for metamodeling in auto-motive design applications

Junqi Yang,Zhenfei Zhan,Kai Zheng,Chong Chen,Jie Hu,Ling Zheng 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.10

Meta-model is frequently employed as the surrogate of high-fidelity finite element models in computer aided engineering. It helps to achieve the trade-off between computational efficiency and predictive accuracy. To improve the predictive capability of meta-models, we developed an uncertainty representation based sampling method to schedule Design of experiment (DOE) for meta-modeling. Several datasets were first generated through a modified Bootstrap method for datasets acquisition, then the influence of the input uncertainty on the output was quantified as weighting factors. The weighting factors were used to integrate the represented distributions into a single one for further sampling. Finally, the sampling results then served as the elements of the DOE matrix to construct meta-models. The proposed method was demonstrated through an analytical case and a real-world vehicle crashworthiness design problem.

Observer-based Stabilization of Uncertain Switched Linear Systems with Admissible Edge-dependent Switching Signals

Junqi Yang,Ying Qiao,Xuhui Bu,Zhiguo Hu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.8

This paper focuses on the stabilization of a class of uncertain switched linear systems with admissible edge-dependent (AED) switching signals, where disturbances exist in not only the state equation but also output equation. The performance of switchings from the current system mode to the other is shown by the concept of admissible transition edge-dependent weights (ATEWs). A special output transformation is adopted to construct a new system with the same states as the original system but different output, where the disturbance in measurement equation is decoupled. Then, a multiple-mode unknown input observer (UIO) with AED switching is proposed to simultaneously estimate the state and disturbance. Next, an observer-based controller is developed to stabilize the uncertain switched system, then the conditions ensuring the stability of the closed-loop system are provided. Finally, the validity of the proposed method is shown by an example.

중국 프로기사의 생활 실태 조사 분석

Wang Junqi,김진환 국제바둑학회(구 한국바둑학회) 2020 바둑학연구 Vol.16 No.1

PSMD12 promotes non-small cell lung cancer progression through activating the Nrf2/TrxR1 pathway

Lv Junqi,Ma Shengmao,Wang Xiaowen,Dang Jifang,Ma Fuchun 한국유전학회 2024 Genes & Genomics Vol.46 No.3

Background Non-small cell lung cancer (NSCLC) contributes to the vast majority of cancer-related deaths. Proteasome 26S subunit, non-ATPase 12 (PSMD12), a subunit of 26S proteasome complex, is known to play the tumor-promoting role in several types of cancer but its function in NSCLC remains elusive. Objective To explore the role and underlying mechanisms of PSMD12 in NSCLC. Methods The PSMD12 expression in human normal lung epithelial cell line (BEAS-2B) and four NSCLC cell lines (A549, NCI-H1299, NCI-H1975, Calu-1) were determined by qRT-PCR and western blot. Malignant phenotypes of NSCLC cells were detected by CCK-8, EdU staining, immunofluorescence staining for E-cadherin, flow cytometry, and Transwell assays to assess cell viability, proliferation, epithelial-mesenchymal transition (EMT), apoptosis, migration and invasion. Dual luciferase assay was used to verify the regulatory role of transcription factor on the promoter. Results We identified the upregulation of PSMD12 in NSCLC tissues based on the GEO datasets, which further verified in NSCLC and BEAS-2B cell lines. PSMD12 knockdown significantly suppressed malignant behaviors of NSCLC cells, including cell growth, invasion, and migration, while PSMD12 overexpression presented the opposite effects. Interestingly, we found that PSMD12 upregulated the tumor-promoting factor TrxR1 mRNA expression. For its potential mechanisms, we demonstrated that PSMD12 elevated transcription factor Nrf2 protein level and promoted Nrf2 nuclear translocation. And Nrf2 further increased TrxR1 promoter activity and enhanced TrxR1 transcription. Meanwhile, we proved that TrxR1 overexpression erased the inhibitory effect of PSMD12 knockdown. Conclusion PSMD12 promotes NSCLC progression by activating the Nrf2/TrxR1 pathway, providing a novel prognostic and therapeutic target for NSCLC treatment.

Frequency capture characteristic of a vibration system driven by four counterrotating unbalanced rotors

Xiaozhe Chen,Junqi Liu,Jiaqi Zhang,Baitong Zhou 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.4

This study investigates the frequency capture characteristic of four unbalanced rotors in multi-frequency ranges. First, using the average method, the synchronous condition of four unbalanced rotors in a vibration system is derived. Then, the stability condition of the vibration system is deduced, which meets the Routh-Hurwitz criterion. On the basis of the theoretical analysis, the phase difference in steady states and the resultant force on the rigid body at different excitation frequency regions are discussed numerically. Five sets of experiments are done to investigate synchronization and the Sommerfeld effect. The results prove that the vibration system has three motion states according to the excitation frequency in different frequency regions. Two stable states appear in the near-resonance region of the system. This study concludes that the synchronization of unbalanced rotors formed before and after the natural frequency is crucial for the occurrence of the Sommerfeld effect. This work can provide theoretical and experimental reference for the design of new vibration equipment in engineering.