scholarly journals Improving Stability and Accuracy of Cell Viability Evaluation by Fusion of Impedance Spectroscopy Information

Author(s):  
Yecheng Zhang ◽  
Mingji Wei ◽  
Rongbiao Zhang ◽  
Fei Zhang

The increasing attention to precision medicine is widely paid in order to greatly improve the cure rate of cancer. Improving the stability and accuracy of cell viability evaluation is the key of precision medicine, for excess dosage of anti-cancer drugs not only kills the cancer cells, but also does harm to normal cells. Electrochemical impedance sensing (EIS) method is widely accepted as a label-free, non-invasive approach for real-time, online monitoring of cell viability. Due to the large effects of many influencing factors, the existing EIS methods that utilized single-frequency impedances show poor stability and low accuracy of cell viability evaluation. In this paper, we proposed a multi-physical information fusion method based on least squares support vector machine (LS-SVM) for improving the stability and accuracy of cell viability evaluation. The results show that the mean relative error of single-frequency method is about 0.08, while that of fusion method is about 0.04. It means that the prediction results of fusion method are more accurate than that of the single-frequency method. Moreover, the maximum relative error of single-frequency method is up to 0.5 due to the influencing of cell micromotion, while that of fusion method is below 0.07, showing that the fusion method is more stable than single-frequency method.

2010 ◽  
Vol 146-147 ◽  
pp. 460-465 ◽  
Author(s):  
Sheng Hui Guo ◽  
Dong Bo Li ◽  
Li Jun Liu ◽  
Jin Hui Peng ◽  
Li Bo Zhang ◽  
...  

The stability is one most important product performance index, which can directly determine the quality of the partially stabilized zirconia (PSZ), and the stability of PSZ is always fluctuating in the commercial process, so how to accurately, quickly and easily predict the stability of PSZ in the preparation process is very important. In the present paper, a new mathematical model to predict the stability of PSZ was proposed, based on statistical theory (SLT) and support vector machine (SVM) theory, which relates the stability of PSZ and the influence factors, such as the holding temperature, rising rate of temperature, holding time, decreasing rate of temperature and hardening temperature. Typical data collected from commercial process were collected for the training samples and test samples. Then testing and analyzing was done. The results showed that the max relative error was 1.80%, the least relative error was 0%, and the average relative error was 0.58%. It is accurate and reliable to predict the stability of PSZ by SVM model. Besides, multiple influence factors can be comprehensively considered in the SVM model, thus a new highly effective method for predicting the stability of PSZ is provided for commercial application.


2015 ◽  
Vol 69 (4) ◽  
pp. 869-882 ◽  
Author(s):  
Kai Zheng ◽  
Long Tang

Accurate velocity estimates are critical in highly dynamic positioning, airborne gravimetry, and geophysics applications. This paper focuses on the evaluation of the performance of velocity estimation using the BeiDou navigation satellite system (BDS) alone and integrated Global Positioning System (GPS)/BDS. Firstly, we analyse and compare the position-derivation method and analytical method which are used to calculate BDS satellite velocity from broadcast ephemeris. Results show that the accuracy of the estimated velocity by position-derivation method can be within 1 mm/s and better than that of the analytical method. Secondly, velocity estimation tests were carried out both in static and kinematic modes. The results show that: 1) the accuracy of BDS velocity estimation is in the same order of magnitude to that of GPS; 2) Compared with a single navigation system, the stability and accuracy of velocity estimation can be remarkably improved by integrated GPS/BDS, especially under conditions of poor observation; 3) Compared with Helmert variance component estimation, it is more appropriate and efficient to assign the weights of different types of observations using equivalent weight ratio. Finally, the ionospheric influence on velocity estimation with single-frequency observations can reach several mm/s; this influence can be significantly mitigated by using ionosphere-free combination observations.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2830
Author(s):  
Sili Wang ◽  
Mark P. Panning ◽  
Steven D. Vance ◽  
Wenzhan Song

Locating underground microseismic events is important for monitoring subsurface activity and understanding the planetary subsurface evolution. Due to bandwidth limitations, especially in applications involving planetarily-distributed sensor networks, networks should be designed to perform the localization algorithm in-situ, so that only the source location information needs to be sent out, not the raw data. In this paper, we propose a decentralized Gaussian beam time-reverse imaging (GB-TRI) algorithm that can be incorporated to the distributed sensors to detect and locate underground microseismic events with reduced usage of computational resources and communication bandwidth of the network. After the in-situ distributed computation, the final real-time location result is generated and delivered. We used a real-time simulation platform to test the performance of the system. We also evaluated the stability and accuracy of our proposed GB-TRI localization algorithm using extensive experiments and tests.


Author(s):  
Weitao Chen ◽  
Shenhai Ran ◽  
Canhui Wu ◽  
Bengt Jacobson

AbstractCo-simulation is widely used in the industry for the simulation of multidomain systems. Because the coupling variables cannot be communicated continuously, the co-simulation results can be unstable and inaccurate, especially when an explicit parallel approach is applied. To address this issue, new coupling methods to improve the stability and accuracy have been developed in recent years. However, the assessment of their performance is sometimes not straightforward or is even impossible owing to the case-dependent effect. The selection of the coupling method and its tuning cannot be performed before running the co-simulation, especially with a time-varying system.In this work, the co-simulation system is analyzed in the frequency domain as a sampled-data interconnection. Then a new coupling method based on the H-infinity synthesis is developed. The method intends to reconstruct the coupling variable by adding a compensator and smoother at the interface and to minimize the error from the sample-hold process. A convergence analysis in the frequency domain shows that the coupling error can be reduced in a wide frequency range, which implies good robustness. The new method is verified using two co-simulation cases. The first case is a dual mass–spring–damper system with random parameters and the second case is a co-simulation of a multibody dynamic (MBD) vehicle model and an electric power-assisted steering (EPAS) system model. Experimental results show that the method can improve the stability and accuracy, which enables a larger communication step to speed up the explicit parallel co-simulation.


Author(s):  
Yue Zhao ◽  
Feng Gao ◽  
Qiao Sun ◽  
Yunpeng Yin

AbstractLegged robots have potential advantages in mobility compared with wheeled robots in outdoor environments. The knowledge of various ground properties and adaptive locomotion based on different surface materials plays an important role in improving the stability of legged robots. A terrain classification and adaptive locomotion method for a hexapod robot named Qingzhui is proposed in this paper. First, a force-based terrain classification method is suggested. Ground contact force is calculated by collecting joint torques and inertial measurement unit information. Ground substrates are classified with the feature vector extracted from the collected data using the support vector machine algorithm. Then, an adaptive locomotion on different ground properties is proposed. The dynamic alternating tripod trotting gait is developed to control the robot, and the parameters of active compliance control change with the terrain. Finally, the method is integrated on a hexapod robot and tested by real experiments. Our method is shown effective for the hexapod robot to walk on concrete, wood, grass, and foam. The strategies and experimental results can be a valuable reference for other legged robots applied in outdoor environments.


2021 ◽  
Vol 11 (5) ◽  
pp. 2098
Author(s):  
Heyi Wei ◽  
Wenhua Jiang ◽  
Xuejun Liu ◽  
Bo Huang

Knowledge of the sunshine requirements of landscape plants is important information for the adaptive selection and configuration of plants for urban greening, and is also a basic attribute of plant databases. In the existing studies, the light compensation point (LCP) and light saturation point (LSP) have been commonly used to indicate the shade tolerance for a specific plant; however, these values are difficult to adopt in practice because the landscape architect does not always know what range of solar radiation is the best for maintaining plant health, i.e., normal growth and reproduction. In this paper, to bridge the gap, we present a novel digital framework to predict the sunshine requirements of landscape plants. First, the research introduces the proposed framework, which is composed of a black-box model, solar radiation simulation, and a health standard system for plants. Then, the data fitting between solar radiation and plant growth response is used to obtain the value of solar radiation at different health levels. Finally, we adopt the LI-6400XT Portable Photosynthetic System (Li-Cor Inc., Lincoln, NE, USA) to verify the stability and accuracy of the digital framework through 15 landscape plant species of a residential area in the city of Wuhan, China, and also compared and analyzed the results of other researchers on the same plant species. The results show that the digital framework can robustly obtain the values of the healthy, sub-healthy, and unhealthy levels for the 15 landscape plant species. The purpose of this study is to provide an efficient forecasting tool for large-scale surveys of plant sunshine requirements. The proposed framework will be beneficial for the adaptive selection and configuration of urban plants and will facilitate the construction of landscape plant databases in future studies.


2018 ◽  
Vol 10 (12) ◽  
pp. 2018 ◽  
Author(s):  
Ying She ◽  
Reza Ehsani ◽  
James Robbins ◽  
Josué Nahún Leiva ◽  
Jim Owen

Frequent inventory data of container nurseries is needed by growers to ensure proper management and marketing strategies. In this paper, inventory data are estimated from aerial images. Since there are thousands of nursery species, it is difficult to find a generic classification algorithm for all cases. In this paper, the development of classification methods was confined to three representative categories: green foliage, yellow foliage, and flowering plants. Vegetation index thresholding and the support vector machine (SVM) were used for classification. Classification accuracies greater than 97% were obtained for each case. Based on the classification results, an algorithm based on canopy area mapping was built for counting. The effects of flight altitude, container spacing, and ground cover type were evaluated. Results showed that container spacing and interaction of container spacing with ground cover type have a significant effect on counting accuracy. To mimic the practical shipping and moving process, incomplete blocks with different voids were created. Results showed that the more plants removed from the block, the higher the accuracy. The developed algorithm was tested on irregular- or regular-shaped plants and plants with and without flowers to test the stability of the algorithm, and accuracies greater than 94% were obtained.


2017 ◽  
Vol 24 (12) ◽  
pp. 2642-2655 ◽  
Author(s):  
Lida Zhu ◽  
Baoguang Liu ◽  
Hongyu Chen

Cutting stability is the prerequisite to ensure efficient and high-precision machining, resulting in poor surface quality and damaged tool, which is the basis for the optimization of process parameters and improvement of processing efficiency. Aiming at process damping caused by interference between a tool flank face and a machined surface of part, the dynamic model and critical condition of stability is proposed in the paper. The frequency method is applied to solve the stability of the cutting chatter, and the correctness of the model is validated by experiments. Moreover, through orthogonal experiments, regression analysis methodology are adopted to establish a prediction model of surface roughness and finally combined with the study findings on milling stability based on process damping and surface roughness, achieved optimization of the milling parameters by genetic optimization algorithm. This conclusion provides a theoretical foundation and reference for the milling mechanism research.


Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 333
Author(s):  
Jian Le ◽  
Hao Zhang ◽  
Cao Wang ◽  
Xingrui Li ◽  
Jiangfeng Zhu

To enhance the stability and accuracy of the digital-physical hybrid simulation system of a modular multilevel converter-based high voltage direct current (MMC-HVDC) system, this paper presents an improved power interface modeling algorithm based on ideal transformer method (ITM). By analyzing the stability condition of a hybrid simulation system based on the ITM model, the current of a so-called virtual resistance is added to the control signal of the controlled current source in the digital subsystem, and the stability of the hybrid simulation system with the improved power interface model is analyzed. The value of the virtual resistance is optimized by comprehensively considering system stability and simulation precision. A two-terminal bipolar MMC-HVDC simulation system based on the proposed power interface model is established. The comparisons of the simulation results verify that the proposed method can effectively improve the stability of the hybrid simulation system, and at the same time has the advantages of high simulation accuracy and easy implementation.


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