• Journal of Ginseng Research
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• v.40 no.4
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• pp.382-394
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• 2016

Background: Ginsenosides are the characteristic and principal components which manifest a variety of the biological and pharmacological activities of the roots and rhizomes of Panax ginseng (GRR). This study was carried out to qualitatively and quantitatively determine the ginsenosides in the cultivated and forest GRR. Methods: A rapid and sensitive ultra-high-performance liquid chromatography coupled with diode-array detector and quadrupole/time of flight tandem mass spectrometry (UPLC-DAD-QTOF-MS/MS) was applied to the qualitative analysis of ginsenosides and a 4000 QTRAP triple quadrupole tandem mass spectrometer (HPLC-ESI-MS) was applied to quantitative analysis of 19 ginsenosides. Results: In the qualitative analysis, all ingredients were separated in 10 min. A total of 131 ginsenosides were detected in cultivated and forest GRR. The method for the quantitative determination was validated for linearity, precision, and limits of detection and quantification. 19 representative ginsenosides were quantitated. The total content of all 19 ginsenosides in the forest GRR were much higher than those in the cultivated GRR, and were increased with the growing ages. Conclusion: This newly developed analysis method could be applied to the quality assessment of GRR as well as the distinction between cultivated and forest GRR.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.10-19
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• 2021

In this paper, we tried to derive characteristic parameters that reflect mental fatigue through EEG measurement and analysis. For this purpose, mental fatigue was induced through a resting state with eyes closed and performing subtraction operations in mental arithmetic for 30 minutes. Five subjects participated in the experiment, and all subjects were right-handed male students in university, with an average age of 25.5 years. Spectral analysis was performed on the EEG collected at the beginning and the end of the experiment to derive feature parameters reflecting mental fatigue. As a result of the analysis, the absolute power of the alpha band in the occipital lobe and the temporal lobe increased as the mental fatigue increased, while the relative power decreased. Also, the difference in power between resting state and task state showed that the relative power was larger than the absolute power. These results indicate that alpha relative power in the occipital lobe and temporal lobe is a feature parameter reflecting mental fatigue. The results of this study can be utilized as feature parameters for the development of an automated system for mental fatigue determination such as fatigue and drowsiness while driving.

• Journal of Environmental Science International
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• v.15 no.8
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• pp.775-784
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• 2006

In this study, CN value was estimated by using detailed soil map and land cover characteristic against upper basin of Kumho watermark located on the upper basin of Kumho river and the hydrologic morphological characteristic factors were extracted from the basin by using the DEM document. Also the runoff analysis was conducted by the WMS model in order to study how the assumed CN value affects the runoff characteristic. First of all, as a result of studying the soil type in this study area, mostly D type soil was Identified by the application of the 1987 classification criteria. However, by that in 1995, B type soil and C type soil were distributed more widely in that area. When CN value was classified by the 1995 classification criteria, it was estimated lower than in 1987, as a result of comparing the estimated CNs by those standars. Also it was assumed that CN value was underestimated when the plan for Geum-ho river maintenance was drawn up. As a result of the analysis of runoff characteristic, the pattern of generation of the classification criteria of soil groups appeared to be similar, but in the case of the application of the classification criteria in 1995, the peak rate of runoff was found to be smaller on the whole than in the case of the application of the classification criteria in 1987. Also when the statistical data such as the prediction errors, the mean squared errors, the coefficient of determination and other data emerging from the analysis, was looked over in total, it seemed appropriate to apply the 1995 classification criteria when hydrological soil classification group was applied. As the result of this study, however, the difference of the result of the statistical dat was somewhat small. In future study, it is necessary to follow up evidence about soil application On many more watersheds and in heavy rain.

• Journal of the Korean Institute of Telematics and Electronics
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• v.11 no.4
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• pp.29-37
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• 1974

Theoretical analysis is carried out for the curtoff wavelength characteristics of rectangular waveguide containing a step-ridge. In order to obtain the cutoff wavelength of step-rigde waveguide, an transmission matriz is formulated by the method of equivalent transverse resonance. The characteristic equation, in which the wavelength is obtainable by the numerical method, is derived from the equation. An approximate determination of the dominant mode fields in step-ridge waveguides at all frequencies has been made. Using these fields, the characteristic impedance equation is derived from power considerations. Analyzing the results of the calculations, the following characteristics are noted. The values of λ /a of TE10 mode increase with decreasing gap lengths and with increasing step width S or S , or both. Experimental results of cutoff characteristics are in good agreement with the theoretical analusis. It is shown that a waveguide within which a step-ridge is placed has a lower cutoff frequency and impedance than empty guide without it. Therefore, the role of a step-ridge guide is to broadening the bandwidth 2 to 3 times more than that of an empty guide of the same demension.

• Analytical Science and Technology
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• v.14 no.2
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• pp.173-179
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• 2001

The study was carried out to analyze the pollutant Fe, Cu, Cr, Zn, Cd for sediments collected from lake in K river basin. Three analytical methods currently used in Korea, Japan, U.S.A, were compared. Pretreatment using microwave digestion showed higher analytical results for Fe, Cu, Cr, Zn, Cd than Korean Official Method(KOM) and American Toxicity Characteristic Leaching Procedure(TCLP) Method. Also, analytical results using microwave digestion, TCLP and KOM were as follows: 38.1-48.0 mgFe/kg, 10.2-15.9 mgFe/kg AND 3.5-12.6 mgFe/kg, 37.0-50.1 mgCu/kg, 0.06-0.24 mgCu/kg and 0.01-0.03 mgCu/kg, 137.0-152.0 mgZn/kg, 0.67-0.82 mgZn/kg and 0.3-0.5 mgZn/kg, respectively. From this result, a new analytical method for the determination of heavy metal in sediment should be developed for the accurate estimation of pollution degree in sediment.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.128-137
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• 1999

Plasma progesterone (P$_4$) concentrations were measured for confirming the estrus observation and for the early pregnancy diagnosis in 130 cows of small farmers. Ultrasonographic examinations were performed from day 30 after artificial insemination to establish the characteristic ultrasonographic appearances of gestational structures in each pregnant stages. Of the 130 cows inseminated, 111 cows (85.4%) were an ovulatory estrus, 12 cows (9.2%) were an unovulatory estrus, and 7 cows (5.4%) were the error of estrus detection, respectively. The accuracy for early pregnancy diagnosis in 111 ovulatory estrus cows achieved when the discriminatory concentration at day 21 after artificial insemination was placed at 3.0 ng-/ml in plasma, was 86.7 % for positive diagnosis and 100% for negative diagnosis, respectively. Pregnancy diagnosis by ultrasonography were performed to evaluate gestational structures from day 30 after artificial insemination in 83 cows. Pregnant cows were 72 of 83 cows. The characteristic ultrasonography of gestational structures in each gestational stages was as follows. The embryo proper was observed within anechoic fetal fluid between 28 and 40 days after insemination, and amnion and embryonic heartbeat was also detected in this period. Between days 41 and 50, embryo proper was detected as an discriminated from head and body, and forelimb buds and hindlimb buds were also observed in this period. Between days 51 and 60, an embryo proper was clearly discriminated from head and body, and fetal movement, forelimb buds and hindlimb buds were observed in this period. Between days 61 and 70, fetus was completely developed, and fetal skeleton, organs and cotyledon were observed. After day 71, each organs of fetus were rapidly developed and a fetus was partially observed in screen because fetus was too big and larger, These results indicate that plasma P$_4$ determination at days 0,6 and 21 after artificial insemination can be utilized for confirming the estrus observation and for early pregnancy diagnosis. Also, ultrasonography was reliable method for early pregnancy diagnosis at day 30 after artificial insemination.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.8
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• pp.753-760
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• 2008

The present study is concerned with aerodynamic characteristics and reference trajectory generation of Hope-X in Approach/Landing phase. To create reference trajectory generation in A/L phase, detailed informations on lift and drag coefficients of Hope-X must be provided. To obtain these informations, aerodynamic characteristics of Hope-X are analyzed using the commercial CFD code, Fluent. The A/L phase is conceptually divided into three sub-phases: the Steepglide Slope phase for stability of vehicle, the Flare Maneuver phase for safety landing, the Circular Flare for smooth connecting with these both phases. The reference trajectory is obtained by determination of flight-path angle through geometrical formulas with consideration of aerodynamic coefficient and dynamic characteristic.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.214-221
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• 2001

This paper describes the design of 3-component force/moment sensor with the force and moment ratio of wide range. It can measure the x-direction force Fx, y-direction force Fy and z-direction moment Mz simultaneously. In order to accurately measure forces and moment using 3-component force/moment sensor, it should get suitable force and moment ratio(the ratio of force Fx=200 N and moment Mz=20 Nm is ten to one), and small interference error. In this paper, in order to design the 3-component force/moment sensor with the force and moment ratio of wide range, the procedures are performed as follow : 1) the derivation of the equations to predict the bending strains on the surfaces of the plate-beams under the force or the moments, 2) the determination of the size of the sensing elements of the force/moment sensor by using the derived equations, 3) the Finite Element Method(FEM) analysis and the characteristic test for confirming the strains from the theory analysis, 4) the selection of the attachment locations of the strain gages of each sensor, 5) the analysis of the rated strain and the interference error at the attachment location of strain gages. It reveals that the rated strains calculated from the derived equations make a good agreement with the results from the Finite Element Method analysis and the characteristic test.

• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.289-298
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• 2000

In order to minimize the impact of water hammer In a pipeline, a determination of optimum position of hydraulic structures with best operation of pressure relief valve was explored at the Seobyun pumping station. Method of characteristics is used to simulate a surge impact originating from abrupt stop of pumping operation in a pipeline. Genetic algorithm shows a powerful capability in searching a global solution, especially for a nonlinear problem The application results suggests that the maximum positive pressure can be relaxed by decreasing the opening time of pressure relief valve, meanwhile the maximum negative pressure can be relaxed by increasing the opening time of pressure relief valve. This study shows that the integration of a genetic algorithm with a transient analysis technique such as method of characteristic can improve the design of hydraulic structure in a pipe network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2982-2988
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• 2014

The edge detection is a pre-processing of such as image segmentation, image recognition, etc, and many related studies are being conducted both in domestic and abroad. Representative edge detection methods are Sobel, Prewitt, Laplacian, Roberts and Canny edge detectors. Such existing methods are possible for superb detections of edges if edges are detected from videos without noises. However, for video degraded by the salt-and-pepper noise, the edge detection characteristic is shown to be insufficient due to the noise influence. Therefore, in this study, the area is separated as the top, down, left and right from the mask's center pixel first to acquire a superb edge detection characteristic from the video damaged by the salt-and-pepper noise. And the algorithm that detects the final edge by applying the directional mask on the assumed factor of mask that is obtained according to the result of determination for the noise status of representative pixel value of each area.