Wearable Monitoring and Predicting System for Knee Joint Fatigue Based on Curvature and Pressure Sensing

Abstract Background Knee injury is always a trouble for people in daily life. It not only threatens the career of an athlete but also affects a normal engineer through morning running. The injury of the knee joint is found to be directly related to the fatigue caused by excessive exercise. Methods An economical embedded system with a designed acceleration-weighted curve fitting method was developed to estimate and predict the knee fatigue state. Then the warning message and recommended lasting time were sent to users to avoid excessive exercise. 24 healthy volunteers were involved in the experiments to verify the effectiveness of the system compared to human perception. Results Only using human perception to prevent knee joint fatigue had a risk of failure while the designed wearable system could protect knee successfully. It was also found that the knee of female was more likely to be injured than the one of male in intense exercises and a high BMI value could influence the risk of knee injuries during sports. However, a short break in sports could significantly extend the healthy time for knee. Conclusions Early warning from the specially designed embedded system can successfully help people avoid knee joint fatigue and injuries during exercises, such as running, badminton, table tennis and basketball.

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Wearable Monitoring and Predicting System for Knee Joint Fatigue Based on Curvature and Pressure Sensing (Preprint)

10.2196/preprints.23540 ◽

2020 ◽

Author(s):

Jiawei Xin ◽

Jialun Chen ◽

Xuanyu Huang ◽

Xiaodong Pan ◽

Tengyue Zou

Keyword(s):

Knee Joint ◽

Embedded System ◽

Knee Injuries ◽

Human Perception ◽

Table Tennis ◽

Embedded Devices ◽

Excessive Exercise ◽

Fitting Method ◽

Curve Fitting Method ◽

The One

BACKGROUND Knee injury is always a trouble for people in daily life. It not only threatens the career of an athlete but also affects a normal engineer through morning running. The injury of the knee joint is found to be directly related to the fatigue caused by excessive exercise. OBJECTIVE The aim of the study was to explore the use of wearable embedded devices to monitor and predict the fatigue degree of the knee joint during exercise, so as to prevent the knee joint from being injured. METHODS An economical embedded system with a designed acceleration-weighted curve fitting method was developed to estimate and predict the knee fatigue state. Then the warning message and recommended lasting time were sent to users to avoid excessive exercise. 24 healthy volunteers were involved in the experiments to verify the effectiveness of the system compared to human perception. RESULTS Only using human perception to prevent knee joint fatigue had a risk of failure while the designed wearable system could protect knee successfully. It was also found that the knee of female was more likely to be injured than the one of male in intense exercises and a high BMI value could influence the risk of knee injuries during sports. However, a short break in sports could significantly extend the healthy time for knee. CONCLUSIONS Early warning from the specially designed embedded system can successfully help people avoid knee joint fatigue and injuries during exercises, such as running, badminton, table tennis and basketball.

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One Parameter Chi-squared Analysis

Chi-Squared Data Analysis and Model Testing for Beginners ◽

10.1093/oso/9780198847144.003.0003 ◽

2019 ◽

pp. 18-31

Author(s):

Carey Witkov ◽

Keith Zengel

Keyword(s):

Curve Fitting ◽

Physical Experiments ◽

Fitting Method ◽

Wide Range ◽

Chi Squared ◽

Measurement Uncertainties ◽

Distributed Measurement ◽

Curve Fitting Method ◽

The One ◽

Parameter Case

The chi-squared method for parameter estimation and model testing is developed for the one-parameter case of a line with a slope but no intercept. Curve fitting is motivated, and several methods for curve fitting are introduced. The chi-squared method is shown to be the optimal curve fitting method whenever Gaussian distributed measurement uncertainties and a model are present. The central limit theorem, which assures Gaussian distributed measurement uncertainties for a wide range of physical experiments, is introduced. End-of-chapter problems are included (with solutions in an appendix).

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A Digital Investigation Manifesting use of Geometric Stencils for the Drawing of Akrotiri Thera Prehistoric Wall Paintings

Pattern Recognition and Signal Processing in Archaeometry ◽

10.4018/978-1-60960-786-9.ch003 ◽

2011 ◽

pp. 64-145

Author(s):

Panayiotis Rousospoulos ◽

Dimitris Arabadjis ◽

Mihalis Exarhos ◽

Michail Panagopoulos ◽

Georgios Galanopoulos ◽

...

Keyword(s):

Bronze Age ◽

Curve Fitting ◽

Digital Images ◽

Late Bronze Age ◽

Wall Paintings ◽

Main Hypothesis ◽

Fitting Method ◽

Digital Investigation ◽

Curve Fitting Method ◽

The One

The present chapter deals with the problem of determining the method used to draw several celebrated and beautiful wall-paintings belonging to the Late Bronze Age (c. 1630 B.C.), that were excavated at Akrotiri, Thera, Hellas (Greece). First, the authors process the wall paintings’ digital images in order to extract the contour of their main thematic entities. Subsequently, a number of fundamental definitions are given and the main hypothesis is stated, namely that geometrical stencils were used for the drawing of the considered wall paintings. A first estimation of the probable one stoke parts of the contour is undertaken, based on curvature considerations and minimization of corresponding error functions. Next, they select families of geometrical curves as potential prototypes of the employed stencils. The selection is based on archaeological and historical criteria. A novel exhaustive curve fitting method is introduced that offers unambiguously optimal matching of two digital curves. Taking into consideration the previous stages, the exact values of the stencils’ parameters are determined. Finally, the hypothesis that stencils were used for the drawing of the considered wall paintings is supported substantially by a visual representation of the one stroke parts together with the corresponding stencil segments that generated them.

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Study of heterogeneous vertical hyporheic flux via streambed temperature at different depths

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-368-168-2015 ◽

2015 ◽

Vol 368 ◽

pp. 168-173

Author(s):

J. Zhu ◽

L. Shu ◽

C. Lu ◽

J. Li ◽

S. Chen ◽

...

Keyword(s):

Hyporheic Zone ◽

Groundwater Temperature ◽

Fitting Method ◽

Study Results ◽

Heat Transport Equation ◽

Different Depths ◽

Zone Depth ◽

Steady State Heat ◽

Curve Fitting Method ◽

The One

Abstract. The hyporheic flux can be characterized using the heat-tracing method. Based on the analytical solution of the one-dimensional steady-state heat transport equation under vertical groundwater discharge conditions, hyporheic flux was obtained via a curve fitting method. The temperature data used was obtained from monitoring three different sections of the DaWen River, Shandong Province. The distribution of the depth of the hyporheic zone was analysed by a curve relating groundwater temperature and the depth of the hyporheic zone. The study results showed that the vertical hyporheic flux was significantly heterogeneous along the three sections. The hyporheic flux ranged from 99.61 to 356.25 L/m2 per day. In the summer, the low temperature area on streambed profile was in accordance with the high value areas of hyporheic flux. There were several strong discharge zones within the same section and these flux values were normally distributed. The depth of the hyporheic zone was inversely proportional to the hyporheic flux and the hyporheic zone depth, also, presented great spatial heterogeneity.

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Using A Segmented Voltage Sweep Mode and A Gaussian Curve Fitting Method to Improve Heavy Metal Measurement System Performance

Metrology and Measurement Systems ◽

10.2478/v10178-012-0033-8 ◽

2012 ◽

Vol 19 (2) ◽

pp. 381-394

Author(s):

José Pereira ◽

Octavian Postolache ◽

Pedro Girão

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Measurement System ◽

Curve Fitting ◽

System Performance ◽

Redox Potentials ◽

Voltage Sweep ◽

Gaussian Curve ◽

Fitting Method ◽

Curve Fitting Method

Using A Segmented Voltage Sweep Mode and A Gaussian Curve Fitting Method to Improve Heavy Metal Measurement System PerformanceThis paper presents a voltammetric segmented voltage sweep mode that can be used to identify and measure heavy metals' concentrations. The proposed sweep mode covers a set of voltage ranges that are centered around the redox potentials of the metals that are under analysis. The heavy metal measurement system can take advantage of the historical database of measurements to identify the metals with higher concentrations in a given geographical area, and perform a segmented sweep around predefined voltage ranges or, alternatively, the system can perform a fast linear voltage sweep to identify the voltammetric current peaks and then perform a segmented voltage sweep around the set of voltages that are associated with the voltammetric current peaks. The paper also includes the presentation of two auto-calibration modes that can be used to improve system's reliability and proposes the usage of a Gaussian curve fitting of voltammetric data to identify heavy metals and to evaluate their concentrations. Several simulation and experimental results, that validate the theoretical expectations, are also presented in the paper.

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A Useful Curve Fitting Method for Concrete Uniaxial Compressive Experiment Data

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.291-294.1015 ◽

2011 ◽

Vol 291-294 ◽

pp. 1015-1020 ◽

Cited By ~ 1

Author(s):

Chong Jin ◽

Hong Wang ◽

Xiao Zhou Xia

Keyword(s):

Experimental Data ◽

Orthogonal Polynomial ◽

Least Square ◽

Base Function ◽

Concrete Material ◽

Fitting Method ◽

Orthogonal Base ◽

The Matrix ◽

Uniform Function ◽

Curve Fitting Method

Based on the superiority avoiding the matrix equation to be morbid for those fitting functions constructed by orthogonal base, the Legendre orthogonal polynomial is adopted to fit the experimental data of concrete uniaxial compression stress-strain curves under the frame of least-square. With the help of FORTRAN programming, 3 series of experimental data is fitted. And the fitting effect is very satisfactory when the item number of orthogonal base is not less than 5. What’s more, compared with those piecewise fitting functions, the Legendre orthogonal polynomial fitting function obtained can be introduced into the nonlinear harden-soften character of concrete constitute law more convenient because of its uniform function form and continuous derived feature. And the fitting idea by orthogonal base function will provide a widely road for studying the constitute law of concrete material.

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New procedure for determining the strain hardening behavior of sheet metals at large strains using the curve fitting method

Mechanics of Materials ◽

10.1016/j.mechmat.2020.103729 ◽

2021 ◽

Vol 154 ◽

pp. 103729

Author(s):

Quoc Tuan Pham ◽

Myoung-Gyu Lee ◽

Young-Suk Kim

Keyword(s):

Strain Hardening ◽

Curve Fitting ◽

Large Strains ◽

Sheet Metals ◽

Hardening Behavior ◽

Fitting Method ◽

Curve Fitting Method ◽

Strain Hardening Behavior

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Analysis on the Return Period of “7.26” Rainstorm and Flood in 2017 in the Wudinghe Basin

MATEC Web of Conferences ◽

10.1051/matecconf/201824601105 ◽

2018 ◽

Vol 246 ◽

pp. 01105

Author(s):

Shuang-yan Jin ◽

Wen-yong Gao ◽

Si-wu Luo ◽

Ya-jun Gao

Keyword(s):

Return Period ◽

Peak Discharge ◽

Observation Data ◽

Historical Survey ◽

Annual Maximum ◽

Frequency Curve ◽

Recurrence Period ◽

Fitting Method ◽

Curve Fitting Method ◽

Hydrological Station

The return period of "7.26" rainstorm flood in 2017 in Wudinghe basin is analyzed by the method of P-III distribution. The Lijiahe and Dingjiagou stations with long rainfall observation data in the rainstorm area are selected, and the frequency curve of the annual maximum 24 hours rainfall are established, and the recurrence period of rainfall stations in rainstorm area are estimated according to the parameters determined by the curve fitting method. The frequency curve of the annual maximum peak discharge of Baijiachuan hydrological stations and so on are established, and the return period are analyzed in combination with the historical survey floods. The results show that the return period of Zhaojiabian of heavy rainfall center is about 100 years, and which of the other stations over than 200mm in Wudinghe basin is about 30~90 years; while the return period of the peak discharge of Baijiachuan and Suide hydrological station is about 30 and 20 years respectively.

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