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A New Direction of Cancer Classification: Positive Effect of Low-Ranking MicroRNAs
Feifei Li,Minghao Piao,Yongjun Piao,Meijing Li,류근호 질병관리본부 2014 Osong Public Health and Research Persptectives Vol.5 No.5
Objectives: Many studies based on microRNA (miRNA) expression profiles showed a new aspect of cancer classification. Because one characteristic of miRNA expression data is the high dimensionality, feature selection methods have been used to facilitate dimensionality reduction. The feature selection methods have one shortcoming thus far: they just consider the problem of where feature to class is 1:1 or n:1. However, because one miRNA may influence more than one type of cancer, human miRNA is considered to be ranked low in traditional feature selection methods and are removed most of the time. In view of the limitation of the miRNA number, low-ranking miRNAs are also important to cancer classification. Methods: We considered both high- and low-ranking features to cover all problems (1:1, n:1, 1:n, and m:n) in cancer classification. First, we used the correlation-based feature selection method to select the high-ranking miRNAs, and chose the support vector machine, Bayes network, decision tree, k-nearestneighbor, and logistic classifier to construct cancer classification. Then, we chose Chi-square test, information gain, gain ratio, and Pearson’s correlation feature selection methods to build the m:n feature subset, and used the selected miRNAs to determine cancer classification. Results: The low-ranking miRNA expression profiles achieved higher classification accuracy compared with just using high-ranking miRNAs in traditional feature selection methods. Conclusion: Our results demonstrate that the m:n feature subset made a positive impression of low-ranking miRNAs in cancer classification.
Feifei Shen,Meihong Wang,Lingxiang Huang,Feng Qian 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.93 No.-
In chemical industry, most processes face the challenge of high energy consumption. The approachpresented in this study can reduce the energy footprint and increase efficiency. The energy system of aseparation process in ethylene manufacturing is used to demonstrate the effectiveness of the approach. The chilling train system of the separation process in a typical ethylene plant consumes most cooling andprovides appropriate feed for distillation columns. The steady state simulation of system was presentedand the simulation results were proved accurate. The conventional exergy analysis identifies thatDephlegmator No.1 (a heat exchange and mass transfer device) has the highest exergy destruction(1401.28 kW). Based on advanced exergy analysis, Dephlegmator No.1 has the highest rate of avoidableexergy destruction (89.04 %). Finally, a multi-objective optimisation aiming to maximise system exergyefficiency and to minimise operational cost was performed and the Pareto frontier was obtained. Themulti-objective optimized exergy efficiency is 79.53 % (improved by 0.61 %) and the operational cost is0.02031 yuan/kg (saved by 11.19 %). This study will guide future research to reduce energy consumptionin process manufacturing.
Feifei Qin,Han Zhao,Shengchao Zhen,Hao Sun,Yan Zhang 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.1
This study designs a control of two-degree of freedom lower limb rehabilitation robot (LLRR) for the patient who needs the proper physical therapy after a spinal cord injury (SCI), stroke, or a surgical operation. The robot manipulator can perform specified passive exercises as well as copy exercise motions and perform them without the physiotherapist. Specifically, the uncertainties including the model uncertainty, initial condition deviation and the external disturbance are also considered. Firstly, a unilateral man-robot dynamical model is proposed based on Lagrange method. Then, we propose a Lyapunov based robust control to suppress the effect of uncertainties. The control algorithm consists of a PD feedback component and a piecewise function component. Theoretical analysis is provided to demonstrate that the controller can guarantee the uniform boundedness and uniform ultimate boundedness of the system. Moreover, the joint angle trajectory of a healthy person is explicitly obtained by the experimental platform and used as the pre-specified trajectory of the LLRR. Finally, numerical simulation is presented to illustrate the effectiveness and the trajectory-tracking control performance of the control.
Bio-inspired Micro Pump Model Based on the Movement Pattern of Sperm
Feifei Liu,Xiaofei Ren,Shoushui Wei,Zhiping Liu 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.11
Micro pumps play important roles in microfluidic system. Biologically inspired actuation mechanisms have great advantages in the micro pump design. This work aims to develop a numerical model for bio-inspired micro pump based on the specific and genuine movement pattern of the sperm. The model also employs a modified immersed boundary-lattice Boltzmann method. In the model, an elastic film is used to mimic a sperm moving with its head fixed. The fluctuation vibration of the film could then drive the static fluid to move. The modified immersed boundary-lattice Boltzmann method directly introduces the velocity information of the film into the traditional lattice Boltzmann equation, which improve the computational efficiency. Pressure distribution, streamlines and the flow rate curves are used to analyze the flow field dynamic process of the model. The effects of the model parameters (e.g. frequency, kinematic viscosity, amplitude and wavelength) on the stable flow rate are also studied comprehensively.
Feifei Chen,Dunke Lu,Xiaohang Li 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7
This paper presents an integrated design of adaptive sliding mode observer and fault-tolerant control for aclass of one-sided Lipschitz Markovian jump systems with general uncertain transition rates. In the design process,an adaptive sliding mode observer is first constructed to estimate the states of the original system without knowingany information of the unknown input. Then a fault-tolerant control strategy is therefore proposed to stabilize theclosed-loop system against the unknown input. Sufficient conditions of the existences of the designed observer andcontroller are deduced in the forms of linear matrix inequalities. In the end, several examples are given to illustratethe effectiveness and make some comparisons with other results.
Feifei Bu,Yuwen Hu,Wenxin Huang,Kai Shi 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.5
This paper presents the control and implementation of the dual-stator-winding induction generator for variable frequency AC (VFAC) generating system. This generator has two sets of stator windings embedded into the stator slots. The power winding produces the VFAC power to feed the loads, and the control winding is connected to the static excitation controller to control the generator for output voltage regulation with speed and load variations. On the basis of the idea of power balance, an instantaneous slip frequency control (ISFC) strategy using the information of both the output voltage and the output power is used in this system. A series of experiments is carried out on a 15 kW prototype for verification. Results show that the system has good static and dynamic performance in a wide speed range, which demonstrates that the ISFC strategy is suitable for this system.
Feifei Zhao,Yanan Li,Li-juan Chen,Lisha Zhu,Han Ren,Honghui Lin,Dehui Xi 한국식물학회 2016 Journal of Plant Biology Vol.59 No.3
Temperature is an important environmental factor controlling plant growth, development, and immune response. However, the role of temperature in plant disease resistance is still elusive. In the present study, the potential effects of temperature on the interaction between Nicotiana tabacum and Cucumber mosaic virus (CMV) were investigated. Our results indicated that N. tabacum plants displayed severe symptoms at early stage of post inoculation at high temperature (HT, 28°C), associated with higher viral replication level, more serious stress damages. By contrast, low temperature (LT, 18°C) effectively delayed the replication of CMV compared with elevated temperatures. Additionally, quantitative real-time PCR analyses revealed that lower temperatures (≤ 24°C) promote salicylic acid (SA) dependent responses, whereas higher temperatures (> 24°C) activate the genes expression of jasmonic acid (JA) pathway. Interestingly, the dark green islands (DGIs) appeared much earlier in CMV-inoculated plants grown at HT compared with those at LT and the accumulation of virus small interfering RNAs in plants were significantly up-regulated under elevated temperatures at early stage of post inoculation. Taken together, these results indicated that temperature changes had important effects on plant defence response, and different temperatures could induce different immune pathways of N. tabacum against CMV infection.