• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.238-244
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• 2013

In energy dispersive X-ray fluorescence analysis, the removal of the continuum on which the X-ray spectrum is superimposed is one of the most important processes, since it has a strong influence on the analysis result. The existing methods which have been used for it usually require tight constraints or prior information on the continuum. In this paper, an efficient background correction method is proposed for Energy Dispersive X-ray fluorescence (EDXRF) spectra. The proposed method has two steps of background modeling and background correction. It is based on the basic concept which differentiates background areas from the peak areas in a spectrum and the SNIP algorithm, one of the popular methods for background removal, is used to enhance the performance. After detecting some points which belong to the background from a spectrum, its background is modeled by a curve fitting method based on them. And then the obtained background model is subtracted from the raw spectrum. The method has been shown to give better results than some of traditional methods, while working under relatively weak constraints or prior information.

• Near Infrared Analysis
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• v.1 no.1
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• pp.31-35
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• 2000

Near-infrared reflectance spectroscopy(NIRS) was used to determine the humic acids in soil samples from the fields of different crops and land-use over Youngnam and Honam regions in Korea. An InfraAlyzer 500 scanning spectrophotometer was obtained near infrared relectance spectra of soil at 2-nm intervals from 1100 to 2500nm. Multiple linear regression(MLR) or partial least square regression (PLSR) was used to evaluate a NIRS method for the rapid and nondestructive determination of humic acid, fulvic acid and its total contents in soils. The raw spectral data(log 1/R) can be used for estimating humic acid, fulvic acid and its total contents in soil by MLR procedure between the content of a given constituent and the spectral response of several bands. In which the predicted results for fulvic acid is the best in the constituents. The new spectral data are converted from the raw spectra by PLSR method such as the first derivative of each spectrum can also be used to predict humic acid and fulvic acid of the soil samples. A low SEC, SEP and a high coefficient of correlation in the calibration and validation stages enable selection of the best manipulation. But a simple calibration and prediction method for determining humic acid and fulvic acid should be selected under similar accuracy and precision of prediction. NIRS technique may be an effective method for rapid and nondestructive determination for humic acid, fulvic acid and its total contents in soils.

• Journal of the Korean Society of Radiology
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• v.2 no.2
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• pp.5-10
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• 2008

Most of the diagnostic medical radiography are rapidly replaced by digital imaging systems recently. Although with the current transition of analog to digital most of the exposure conditions and parameters are still on the basis of film-screen analog system. Moreover the evaluation of acquired digital radiographic image is not fulfilled normally because of the difficulties in handling the digital raw data. The user friendly windows program for the evaluations of digital radiographic image was developed on the MatLab platform. The program has functions for the calculation of the contrast profile, NPS(noise power spectrum), MTF(modulation transfer function), and NEQ(noise equivalent quanta).

• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.29-34
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• 1989

300 MHz proton NMR spectra of human blood plasma were analyzed by deconvolution of spectrum, and we compared its results with Fossel's test in normal (15 cases), liver cancer (14 cases) , and other cancer (14 cases) groups. This analysis had enabled us to obtain dynamic characteristics of each individual lipoprotein. As a result of deconvolution method, the VLDL and chylomicron intensity level were found to be elevated in the patients with liver cancer. Moment ratio values of $CH_2$ resonance in the raw spectrum were found to be higher than the normal group for patients with, malignant tumors other than liver cancer. These differences between the three groups could not be found in the conventional Fossel's test. We could simulate plasma spectra by addition of spectra of individual lipoproteins through deconvolution method. Further clinical trials in larger populations and additional biochemical method may shed new light on many of clinical and biochemical interests for knowing characteristics about lipoprotein not separated from blood and the background of Fossel test.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.495-500
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• 2011

Separation of naphthalene from pyrolyzed fuel oil, by product of Naphta cracking process (NCC) process, has been accomplished by the solvent extraction, distillation and purification process. The residual pyrolyzed fuel oil (PFO), called precursor of carbon materials, has been calcined at $300{\sim}800^{\circ}C$ in nitrogen gas to raw pitch. After the treatment of PFO by hexane and methanol, either a flake phased carbon at $350^{\circ}C$ or a carbon sphere at above $400^{\circ}C$ forms. As the calcination temperature increases, the shape of raw pitch changes from the flake phase to the sphere one, and the size of them decreases to several ${\mu}m$. Based on the BET and XRD spectrum, the carbon sphere is classified to a mesophase amorphous carbon with a cubic phase.

• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.301-313
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• 2017

Purpose: This study was conducted to discriminate between normal hulled barley and Fusarium (Fusarium asiaticum and Fusarium graminearum) infected hulled barley by using the near-infrared spectroscopy (NIRS) technique. Methods: Fusarium asiaticum and Fusarium graminearum were artificially inoculated in hulled barley and the reflectance spectrum of the barley spike was obtained by using a near-infrared spectral sensor with wavelength band in the range 1,175-2,170 nm. After obtaining the spectrum of the specimen, the hulled barley was cultivated in a greenhouse and visually inspected for infections. Results: From a partial least squares discriminant analysis (PLS-DA) prediction model developed from the raw spectrum data of the hulled barley, the discrimination accuracy for the normal and infected hulled barley was 99.82% (563/564) and 100% (672/672), respectively. Conclusions: NIRS is effective as a quick and nondestructive method to detect whether hulled barley has been infected with Fusarium. Further, it expected that NIRS will be able to detect Fusarium infections in other grains as well.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.1
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• pp.55-64
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• 2004

Conventional bipolar surface electromyography(EMG) technique detects only the superimposed electromyographic activity of a large number of motor units due to its low spatial resolution. For the diagnosis of neuromuscular disorder, the information of single MU is required. In this paper, 9 channel array surface electrode system was as designed and MLoG filter was proposed. Also the MCPT(modified convolution processing technique)method was proposed for the improvement of MUAP resolution. For performance evaluation, power spectrum analysis of random data and raw EMG signal comparison of MUAP shape and quantitative estimation of SNR were executed. As a result, the MUAP resolution improvement of 32％ was obtained from the standpoint of the signal-to-noise ratio(SNR).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.635-636
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• 2012

In the present work, investigations by high frequency resonance technique for diagnosis of defect frequencies of linear motion unit are reported. Raw vibration signature of the moving parts at different speeds of operation has been demodulated. Envelope detected spectrum is analyzed to evaluate various defect frequencies and their energy levels. Experimentally evaluated frequencies are compared with theoretically determined defect frequencies. These frequency values and their energy levels are used to monitor intrinsic condition of linear motion unit as well as to establish severity of existing/developed defects on the LM guide and inside the LM block. Relative comparisons of linear motion units of the same type are made at various operating speeds under identical conditions of operation on the basis of identified defect frequencies and severity of defects.

• The Journal of Korea Robotics Society
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• v.7 no.1
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• pp.45-56
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• 2012

This paper proposes how to improve the performance of CSS-based indoor localization system. CSS based localization utilizes signal flight time between anchors and tag to estimate distance. From the distances, the 3-dimensional position is calculated through trilateration. However the error in distance caused from multi-path effect transfers to the position error especially in indoor environment. This paper handles a problem of reducing error in raw distance information. And, we propose the new localization method by pattern matching instead of the conventional localization method based on trilateration that is affected heavily on multi-path error. The pattern matching method estimates the position by using the fact that the measured data of near positions possesses a high similarity. In order to gain better performance of localization, we use EKF(Extended Kalman Filter) to fuse the result of CSS based localization and robot model.

• Smart Structures and Systems
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• v.6 no.4
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• pp.389-403
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• 2010

By using image recognition technology, this paper presents a new fault diagnosis method for rotating machinery with artificial immune algorithm. This method focuses on the vibration state parameter image. The main contribution of this paper is as follows: firstly, 3-D spectrum is created with raw vibrating signals. Secondly, feature information in the state parameter image of rotating machinery is extracted by using Wavelet Packet transformation. Finally, artificial immune algorithm is adopted to diagnose rotating machinery fault. On the modeling of 600MW turbine experimental bench, rotor's normal rate, fault of unbalance, misalignment and bearing pedestal looseness are being examined. It's demonstrated from the diagnosis example of rotating machinery that the proposed method can improve the accuracy rate and diagnosis system robust quality effectively.