• 제목/요약/키워드: Root Mean Square (RMS)

Search Result 494, Processing Time 0.046 seconds

Relationship between EMG Signals and Work during Isokinetic Exercise of Knee Extensor (슬관절 신전근의 등속성 운동 시 발생되는 일과 근전도 신호와의 관계)

  • Won, Jong-Im
    • Journal of Korean Physical Therapy Science
    • /
    • v.10 no.1
    • /
    • pp.83-89
    • /
    • 2003
  • An electromyogram (EMG) using surface electrodes is one of the indirect tests most frequently used to ascertain muscle fatigue. An EMG can be used in two ways. The first technique determines the root mean square (RMS), which reflects the amplitude of the EMG signal. The second technique determines the median and mean power frequencies through EMG power spectrum analysis. The purpose of this article is for determine the correlation between work and percent root mean square(%RMS) and between work and MDF of EMG based on muscle contractions. It is used the %RMS, which reflects the amplitude of the EMG signal For MDF, it is used the frequency power spectrum analysis method, which involves the fast Fourier transformation (FFT) of the original Signals.

  • PDF

An Efficient Ultrasonic SAFT Imaging for Pulse-Echo Immersion Testing

  • Hu, Hongwei;Jeong, Hyunjo
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.37 no.2
    • /
    • pp.84-90
    • /
    • 2017
  • An ultrasonic synthetic aperture focusing technique (SAFT) using a root mean square (RMS) velocity model is proposed for pulse-echo immersion testing to improve the computational efficiency. Considering the immersion ultrasonic testing of a steel block as an example, three kinds of imaging were studied (B-Scan, SAFT imaging based on ray tracing technology and RMS velocity). The experimental results show that two kinds of SAFT imaging have almost the same imaging performance, while the efficiency of RMS velocity SAFT imaging is almost 25 times greater than the SAFT based on Snell's law.

Ultrasonic Inspection of Internal Defects of Potatoes (초음파를 이용한 감자의 내부결함검사)

  • Kim, In-Hoon;Jung, Kyu-Hong;Jang, Kyung-Young;Seo, Ryun;Kim, Man-Soo
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.20 no.3
    • /
    • pp.82-88
    • /
    • 2003
  • The nondestructive internal quality evaluation of agricultural products has been strongly required from the needs for individual inspection. Recently, the ultrasonic wave has been considered as a solution fur this problem, and an ultrasonic system was constructed for the ultrasonic NDE of fruits and vegetables in our previous work. In this paper, the practical applicability of our ultrasonic system is tested fur the inspection of internal defects (central cavity) in Atlantic potato. Sound speed and RMS of transmitted ultrasonic wave signal were measured and classification algorithm using 2 dimensional stochastic analysis. was presented. Experimental results showed greater value of sound speed and RMS (root mean square) of transmitted signal in normal samples than in abnormal samples with cavity. Also a stochastic method to distinguish normal and abnormal showed fault detection rate less than 5%.

A study on the investigation of AE during orthogonal metal cutting (2次元 切削時 發생하는 AE에 관한 硏究)

  • Kang, Myung-Soon;Choi, Seong-Joo;Park, Hyun
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.10 no.6
    • /
    • pp.906-915
    • /
    • 1986
  • This study reviewed the theory of acoustic emission applying generation of acoustic emission in metal cutting and proposed a relationship between fundamental cutting parameters and the root mean square (RMS) voltage of the acoustic emission on the basis of the mechanics of the orthogonal cutting operation. Experimental results are presented for 6063-T5 Auminum and the validity of this relationship is evaluated by a series of tests varying cutting speed, feed rate and rake angle in orthogonal cutting. The original formula derived theoretically has been modified in order to utilize independent of fundamental cutting parameters. RMS voltage of acoustic emission depends on cutting speed and strain rate, but it is not much affected by feed rate. Applying lubricant, the drop of RMS level has been observed.

A CMOS RF Power Detector Using an AGC Loop (자동 이득제어 루프를 이용한 CMOS RF 전력 검출기)

  • Lee, Dongyeol;Kim, Jongsun
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.51 no.11
    • /
    • pp.101-106
    • /
    • 2014
  • This paper presents a wide dynamic range radio-frequency (RF) root-mean-square (RMS) power detector using an automatic gain control (AGC) loop. The AGC loop consists of a variable gain amplifier (VGA), RMS conversion block and gain control block. The VGA exploits dB-linear gain characteristic of the cascade VGA. The proposed circuit utilizes full-wave squaring and generates a DC voltage proportional to the RMS of an input RF signal. The proposed RMS power detector operates from 500MHz to 5GHz. The detecting input signal range is from 0 dBm to -70 dBm or more with a conversion gain of -4.53 mV/dBm. The proposed RMS power detector is designed in a 65-nm 1.2-V CMOS process, and dissipates a power of 5 mW. The total active area is $0.0097mm^2$.

RMS Detector of Multiharmonic Signals

  • Petrovic, Predrag B.
    • ETRI Journal
    • /
    • v.35 no.3
    • /
    • pp.431-438
    • /
    • 2013
  • This paper presents a new realization of the implicit root-mean-square (RMS) detector, employing three second-generation current conveyors and MOS transistors. The proposed circuit can be applied in measuring the RMS value of complex, periodic signals, represented in the form of the Fourier series. To verify the theoretical analysis, circuit Simulation Program with Integrated Circuit Emphasis simulations and experiment results are included, showing agreement with the theory.

A Study on the Detection of the Chatter Using Current Signal in Turning (선삭가공시 전류신호를 이용한 채터 검출에 관한 연구)

  • 서한원;유기현;오석형;서남석
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1997.04a
    • /
    • pp.947-951
    • /
    • 1997
  • Recently, the necessity of the detection of abnormal machining process is being emphasized in order to improve the machining accuracy and reduce the cost in unmanned operating system. The vibration by chatter generated in cutting processes within machine tools is a relative motion between tools and workpieces. So, if the chatter occurs, the surface roughness and accuracy of workpieces will be deteriorate and it leads to the rapid wear of tools. The author intended to use the I /sab/RMS (current of root mean square) of current sigals and the movimg C.V. (coefficient of variation) of each phase for the detection method of chatter.

  • PDF

A Study on Evaluation of Whole-Body Vibration from Vehicle for Different Road Surfaces

  • Kim, Su-Hee;Kim, Tae-Gu
    • International Journal of Safety
    • /
    • v.7 no.1
    • /
    • pp.26-29
    • /
    • 2008
  • The purpose of this study is the measurement of whole-body vibration for different road surfaces. Experimental measurements were taken on asphalt, cement, and off-road surfaces as defined by ISO 2631-1. Each experiment was conducted under the same set of conditions (measurement duration, times, speed, vehicle type). Measurement duration was 10 minutes and 3 separate measurements were taken on each road surface. Vehicle speed was 60km/h. In accordance with ISO 2631-1, an acceleration sensor is set up between the driver's seat and the human body. For evaluation, RMS(root-mean-square) values were taken as suggested by ISO 2631-1. The results suggest "health guidance caution zones", and the evaluation was based on obtaining the vector sum with "health guidance caution zones".

Performance and Root Mean Squared Error of Kernel Relaxation by the Dynamic Change of the Moment (모멘트의 동적 변환에 의한 Kernel Relaxation의 성능과 RMSE)

  • 김은미;이배호
    • Journal of Korea Multimedia Society
    • /
    • v.6 no.5
    • /
    • pp.788-796
    • /
    • 2003
  • This paper proposes using dynamic momentum for squential learning method. Using The dynamic momentum improves convergence speed and performance by the variable momentum, also can identify it in the RMSE(root mean squared error). The proposed method is reflected using variable momentum according to current state. While static momentum is equally influenced on the whole, dynamic momentum algorithm can control the convergence rate and performance. According to the variable change of momentum by training. Unlike former classification and regression problems, this paper confirms both performance and regression rate of the dynamic momentum. Using RMSE(root mean square error ), which is one of the regression methods. The proposed dynamic momentum has been applied to the kernel adatron and kernel relaxation as the new sequential learning method of support vector machine presented recently. In order to show the efficiency of the proposed algorithm, SONAR data, the neural network classifier standard evaluation data, are used. The simulation result using the dynamic momentum has a better convergence rate, performance and RMSE than those using the static moment, respectively.

  • PDF

A Study on the Evaluation of Repeated Measurement Stability of 3D Tooth Model Obtained by Several Dental Scanners (수종의 치과용 스캐너로 채득된 3차원 치아 모형의 반복측정 안정성 평가 연구)

  • Bae, Eun-Jeong;Kim, Won-Soo;Lim, Joong Yeon
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.5
    • /
    • pp.996-1003
    • /
    • 2021
  • The purpose of this study is to evaluate the reliability of repeated measurements of several dental scanners. Blue-lighted scanners, white-light scanners and optical-type scanners are used in the study of repeatability in this study. The measurement results were calculated as root mean square (RMS) and the significance level was confirmed by applying the 1-way ANOVA statistical technique (𝛼=.05). According to the statistical analysis, the scanner with the largest RMS value was Z-opt group (38.2 ㎛. Next, D-white was 35.2 ㎛ and the group with the lowest RMS value was I-blue (34.1 ㎛). The comparison of RMS means between each group was not significant (p>.05). From this result, the blue light had the lowest error in repeatability of dental scanners, but no statistical significance. The conclusion of this study is that the study results are clinically acceptable.