• Title/Summary/Keyword: Linearity Error

Search Result 289, Processing Time 0.027 seconds

The Study on The Skil Development of Optical CT Using Faraday Effects (Faraday효과를 이용한 광CT 기술 개발 연구)

  • Jeon, Jea-Il;Ahn, Mi-Kyoung;Park, Won-Zoo;Lee, Kwang-Sik;Kim, Jung-Bae;Kim, Min-Soo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.18 no.3
    • /
    • pp.109-113
    • /
    • 2004
  • In this paper, we took the basic experiment in order to explore the optical CT(optical current transformer) for measuring high current in a superhigh voltage condition. It is based on the faraday effect that changes the polarization characteristic of optical signals by the magnetic field. We used 1310[nm] laser diode for a light source and comprised a sensing part with the optional fiber of 5[m], 10[m], 20[m] length each. The range of current was from 400[A] to 1300[A]. We observed the characteristic of output that changes according to the length of the optical fiber composing the sensing part. The optical fiber of 5[m] length used for the sensing part had -11.1% of the maximum ratio of error and 10[m] and 20[m] length had -3.5% and 1.7% each. This means that the power and linearity of output increase in proportion to the length of optical fiber and applied current in the same experimental condition.

Prediction of UCS and STS of Kaolin clay stabilized with supplementary cementitious material using ANN and MLR

  • Kumar, Arvind;Rupali, S.
    • Advances in Computational Design
    • /
    • v.5 no.2
    • /
    • pp.195-207
    • /
    • 2020
  • The present study focuses on the application of artificial neural network (ANN) and Multiple linear Regression (MLR) analysis for developing a model to predict the unconfined compressive strength (UCS) and split tensile strength (STS) of the fiber reinforced clay stabilized with grass ash, fly ash and lime. Unconfined compressive strength and Split tensile strength are the nonlinear functions and becomes difficult for developing a predicting model. Artificial neural networks are the efficient tools for predicting models possessing non linearity and are used in the present study along with regression analysis for predicting both UCS and STS. The data required for the model was obtained by systematic experiments performed on only Kaolin clay, clay mixed with varying percentages of fly ash, grass ash, polypropylene fibers and lime as between 10-20%, 1-4%, 0-1.5% and 0-8% respectively. Further, the optimum values of the various stabilizing materials were determined from the experiments. The effect of stabilization is observed by performing compaction tests, split tensile tests and unconfined compression tests. ANN models are trained using the inputs and targets obtained from the experiments. Performance of ANN and Regression analysis is checked with statistical error of correlation coefficient (R) and both the methods predict the UCS and STS values quite well; but it is observed that ANN can predict both the values of UCS as well as STS simultaneously whereas MLR predicts the values separately. It is also observed that only STS values can be predicted efficiently by MLR.

A 125 MHz CMOS Delay-Locked Loop with 64-phase Output Clock (64-위상 출력 클럭을 가지는 125 MHz CMOS 지연 고정 루프)

  • Lee, Pil-Ho;Jang, Young-Chan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2012.10a
    • /
    • pp.259-262
    • /
    • 2012
  • This paper describes a delay-locked loop (DLL) that generates a 64-phase clock with the operating frequency of 125MHz. The proposed DLL use a $4{\times}8$ matrix-based delay line to improve the linearity of a delay line. The output clock with 64-phase is generated by using a CMOS multiplex and a inverted-based interpolator from 32-phase clock which is the output clock of the $4{\times}8$ matrix-based delay line. The circuit for an initial phase lock, which is independent on the duty cycle ratio of the input clock, is used to prevent from the harmonic lock of a DLL. The proposed DLL is designed using a $0.18-{\mu}m$ CMOS process with a 1.8 V supply. The simulated operating frequency range is 40 MHz to 200 MHz. At the operating frequency of a 125 MHz, the worst phase error and jitter of a 64-phase clock are +11/-12 ps and 6.58 ps, respectively.

  • PDF

Brain Alpha Rhythm Component in fMRI and EEG

  • Jeong Jeong-Won
    • Journal of Biomedical Engineering Research
    • /
    • v.26 no.4
    • /
    • pp.223-230
    • /
    • 2005
  • This paper presents a new approach to investigate spatial correlation between independent components of brain alpha activity in functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). To avoid potential problems of simultaneous fMRI and EEG acquisitions in imaging pure alpha activity, data from each modality were acquired separately under a 'three conditions' setup where one of the conditions involved closing eyes and relaxing, thus making it conducive to generation of alpha activity. The other two conditions -- eyes open in a lighted room or engaged in a mental arithmetic task, were designed to attenuate alpha activity. Using a Mixture Density Independent Component Analysis (MD-ICA) that incorporates flexible non-linearity functions into the conventional ICA framework, we could identify the spatiotemporal components of fMRI activations and EEG activities associated with the alpha rhythm. Then, the sources of the individual EEG alpha activity component were localized by a Maximum Entropy (ME) method that is specially designed to find the most probable dipole distribution minimizing the localization error in sense of LMSE. The resulting active dipoles were spatially transformed to 3D MRls of the subject and compared to fMRI alpha activity maps. A good spatial correlation was found in the spatial distribution of alpha sources derived independently from fMRI and EEG, suggesting the proposed method can localize the cortical areas responsible for generating alpha activity successfully in either fMRI or EEG. Finally a functional connectivity analysis was applied to show that alpha activity sources of both modalities were also functionally connected to each other, implying that they are involved in performing a common function: 'the generation of alpha rhythms'.

Determination of Phenobarbital in Intact Phenobabital Tablets using NIRS (근적외선 분광광도법을 이용한 페노바르비탈정제의 정량법에 관한 연구)

  • Cha, Ki-Won;Ze, Keum Ryon;Youn, Mi Ok;Lee, Su Jung;Choi, Hyun Cheol;Kim, Ho Jung;Kim, Hyo Jin
    • Analytical Science and Technology
    • /
    • v.15 no.2
    • /
    • pp.102-107
    • /
    • 2002
  • This paper describes a rapid determination of phenobarbital in intact phenobarbital tablets using partial least squares regression(PLSR) method of transmittance spectrum of near infrared (NIR) compared with the analytical data of liquid chromatograpy. The linearity, concentration range and precision of this analytical method are studied. The correlation coefficient of the calibration curve is 0.9983 and the standard error of calibration(SEC) is 0.14 %. Intra-day precision and Inter-day precision obtained in this method are CV = 0.45, CV =0.56, respectively.

Quantitative Analysis of Lovastatin in Human Plasma and urine by Reversed-Phase High-Performance Liquid Chromatography (역상 고속액체크로마토그라프법을 이용한 혈장 및 뇨 중 로바스타틴의 정량)

  • Choi, Hye-Jin;Kim, Myoung-Min;Choi, Kyung-Eob
    • YAKHAK HOEJI
    • /
    • v.42 no.5
    • /
    • pp.473-479
    • /
    • 1998
  • Lovastatin (LOVA), a fungal metabolite isolated from cultures of Aspergillus terreus, is a competitive HMG-CoA reductase inhibitor used for the treatment of primary hyper cholesterolemia, and has also been shown to suppress growth in a variety of non-glioma tumor cell lines. A sensitive reversed-phase high-perfonnance liquid chromatographic method with ultraviolet (UV) absorbance detection has been developed to quantitate LOVA in human plasma and urine samples using liquid-liquid extraction procedure. Baseline separation of LOVA and internal standard, simvastatin was achieved on a Novapak $C_{18}$ analytical column with a mobile phase containing 0.025M $NaH_2PO_4$: CAN (35:65, v/v%), adjusted pH to 4.5. The flow rate was set at 1.5ml/min, and the column effluent was monitored by a UV detection at 238nm. The limit of quantification was determined to be 0.5${\mu}$g/ml while extraction efficiency of LOVA ranged from 73.4-82.9% at LOVA concentrations of 0.5 to 10${\mu}$g/ml. Good linearity with correlation coefficients greater than 0.999 was obtained in the range of LOVA concentrations from 0.5 to 10${\mu}$g/ml. The accuracy and the precision were proven excellent with relative standard deviation (RSD, %) and relative error (RE, %) of less than 4.2 and 4.0, respectively. Intraday precision, evaluated at five LOVA concentrations (0.5, 1, 2, 5, 10${\mu}$g/ml) and expressed as RSD ranged from 0-1.82% while the interday precision at the same concentrations ranged from 0.7-10.5%. The analytical method described was then successfully employed for the determination of LOVA concentrations in plasma samples obtained during a phase II clinical trial using high doses of LOVA (30-40mg/kg/day). This method could be further utilized for the ongoing pharmacolkinetic studies and therapeutic drug monitoring of the high-dose LOVA therapy in adenocarcinoma patients.

  • PDF

A Capacitance Deviation-to-Time Interval Converter Based on Ramp-Integration and Its Application to a Digital Humidity Controller (램프-적분을 이용한 용량치-시간차 변환기 및 디지털 습도 조절기에의 응용)

  • Park, Ji-Mann;Chung, Won-Sup
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.37 no.12
    • /
    • pp.70-78
    • /
    • 2000
  • A novel capacitance deviation-to-time interval converter based on ramp-integration is presented. It consists of two current mirrors, two schmitt triggers, and control digital circuits by the upper and lower sides, symmetrically. Total circuit has been with discrete components. The results show that the proposed converter has a linearity error of less than 1% at the time interval(pulse width) over a capacitance deviation from 295 pF to 375 pF. A capacitance deviation of 40pF and time interval of 0.2 ms was measured for sensor capacitance of 335 pF. Therefore, the high-resolution can be known by counting the fast and stable clock pulses gated into a counter for time interval. The application of a novel capacitance deviation-to time interval converter to a digital humidity controller is also presented. The presented circuit is insensitive to the capacitance difference in disregard of voltage source or temperature deviation. Besides the accuracy, it features the small MOS device count integrable onto a small chip area. The circuit is thus particularly suitable for the on-chip interface.

  • PDF

Enzymatic Spectrophotometric Determinations of Acetylcholine and Choline in the Biological Samples (생체 시료 중 아세틸콜린 및 콜린에 대한 효소-분광학적 정량분석)

  • Nam, Myung-Hwa;Lee, Sung-Ho;Kim, Ke-Tack;Hahn, Young-Hee
    • YAKHAK HOEJI
    • /
    • v.56 no.4
    • /
    • pp.222-229
    • /
    • 2012
  • In order to determine acetylcholine and choline in the biological samples, the specific enzymes of acetylcholinesterase (AChE) and choline oxidase (ChO), which utilize acetylcholine and choline as substrates, were employed to convert substrates to $H_2O_2$. The produced $H_2O_2$ was coupled to 4-aminoantipyrine/phenol with peroxidase (PO) yielding quinoneimine dye which was measured at 508 nm. In the present enzymatic spectrophotometric analysis the product at the equilibrium state was measured considering accuracy, precision, time and cost of the analysis. The developed analytical method yielded good linearity (calibration curve; $A_{508}$=9534[acetylcholine]+0.009, correlation coefficient ($R^2$); 0.999) with detection limit of $1.11{\times}10^{-7}M$, reasonable precision (relative standard deviation; 0.10~1.62% at $2.5{\times}10^{-6}M{\sim}1.25{\times}10^{-4}M$) and accuracy (relative error; -0.24~0.97% at $4.13{\times}10^{-6}M{\sim}1.01{\times}10^{-4}M$) for acetylcholine chloride standard solution. The concentrations of acetylcholine and choline in human serum were found as $3.20{\times}10^{-5}M$ and $1.14{\times}10^{-4}M$, respectively. The brain tissues of Sprague-Dawley strain rat contained 9.82${\mu}g/g$ of acetylcholine and 6.53 ${\mu}g/g$ of choline in the cerebrum, while 7.37 ${\mu}g/g$ of acetylcholine and 5.34 ${\mu}g/g$ of choline in the cerebellum.

Design of Readout Circuit with Dual Slope Correction for photo sensor of LTPS TFT-LCD (LTPS TFT LCD 패널의 광 센서를 위한 dual slope 보정 회로)

  • Woo, Doo-Hyung
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.46 no.6
    • /
    • pp.31-38
    • /
    • 2009
  • To improve the image quality and lower the power consumption of the mobile applications, it is the one of the best candidate to control the backlight unit of the LCD module with ambient light. Ambient light sensor and readout circuit were integrated in LCD panel for the mobile applications, and we designed them with LTPS TFT. We proposed noble start-up correction in order to correct the variation of the photo sensors in each panel. We used time-to-digital method for converting photo current to digital data. To effectively merge time-to-digital method with start-up correction, we proposed noble dual slope correction method. The entire readout circuit was designed and estimated with LTPS TFT process. The readout circuit has very simple and stable structure and timing, so it is suitable for LTPS TFT process. The readout circuit can correct the variation of the photo sensors without an additional equipment, and it outputs the 4-levels digital data per decade for input luminance that has a dynamic range of 60dB. The readout rate is 100 times/sec, and the linearity error for digital conversion is less than 18%.

Low-voltage high-linear bipolar OTA and its application to IF bandpass Filter (저전압 고선형 바이폴라 OTA와 이를 이용한 IF 대역통과 필터)

  • Chung, Won-Sup;Son, Sang-Hee
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.44 no.7 s.361
    • /
    • pp.37-44
    • /
    • 2007
  • A low-voltage high-linear bipolar OTA and its application to IF bandpass filter for GSM cellular telephone are presented. The OTA consists of a low-voltage linear transconductor, a translinear current gain cell, and three current mirrors. The bandpass filter is composed of two cascaded identical second-order bandpass filters, which consist of a resistor, a capacitor, and a grounded simulated inductor realized with two OTA's and a grounded capacitor. SPICE simulations using an 8 GHz bipolar transistor-array parameter show that the OTA with a transconductance of 1 mS exhibits a linearity error of less than ${\pm}2%$ over an input voltage range of ${\pm}0.65\;V$ at supply voltages of ${\pm}2.0\;V$. Temperature coefficient of the transconductance is less than $-90ppm/^{\circ}C$. The bandpass filter has a center frequency of 85 MHz and Q-factor of 80. Temperature coefficient of the center frequency is less than $-182ppm/^{\circ}C$. The power dissipation of the filter is 128 mW.