• Journal of Korea Water Resources Association
• /
• v.54 no.6
• /
• pp.355-363
• /
• 2021

The conventional Flow Duration Curve has limitations that it does not consider hydrologic persistence of daily discharge, that the daily discharge is greatly affected by the maximums or minimums, and that the date of occurrence and duration of a specific discharge cannot be known. In this study, we propose a Daily Mode Discharge Curve, which consists of aligning the daily discharge each year by the date of occurrence, calculating the daily mode discharge, and averaging them every 5 days. As a result of reviewing the long-term observational daily discharge data at 8 points upstream and downstream of the mainstream of the 4 major rivers in Korea, it was found that the daily discharge at all points shows hydrological persistence, and the distortion of it was alleviated by using Daily Mode Discharge Curve. We also suggest that the Daily Mode Discharge Curve is useful for utilizing reference discharge such as Drought, Low, Normal, Plentiful, and Flood Discharge.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.04a
• /
• pp.929-932
• /
• 2012

Beat map shows the distribution property of the beating sound in the bell structure. Using the beat map, beat control and beat estimation are available. To draw the beat map, mode pair parameters of the bell are required. However, in case of large bell which is struck by a heavy wooden hammer, it is very difficult to measure the excitation force and to obtain the mode pair parameters. In this paper, we determined the mode pair parameters of the bell from the transmissibility between the roving signal and reference signal, using ODS(operational deflection shape) method. The mode pair data are input to the theoretical model of the beat response and beating waves are generated on the bell circumference. All the numerical and beat map drawing procedures are automatized using Matlab. Finally, the reliability of the beat map generated by the program is verified.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.14 no.2
• /
• pp.164-176
• /
• 1989

With reference to the Spread Spectrum techniqeu diseussed and further extended by many investigators, the Peseudo-noise Code Polarity Modulation (PNCPM) technique has proposed in this paper. By using this new technique of PNCPM, some problems pertaining to the Spread Spectrum mode has been sloved. In addition by the PNCPM mode it is proposed that data shifting can be easily demodulated every clock(frame) by measn of simple hardware implementaton for the purpose of operating of the asynchroniged detection mode. And in this paper it is shown that PNCPM mode can be easily implemented by the CCD correlator, and is applicable to the Spread Spectrum Multiple Access.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.7 no.3
• /
• pp.65-71
• /
• 1997

With the emergence of neural network, there is a revived interest in identification of nonlinear systems. So in this paper, to identify unknown nonlinear systems dynamically we propose DPNN(Dynamic Polynomial Neural Network) using GMDH (Group Method of Data Handling) algorithm. The dynamic system identification using GMDH consists of applying a set of inputloutput data to train the network by dynamically computing the necessary coeffici1:nt sets. Then, MRAC(Mode1 Reference Adaptive Control) is designed to control nonlinear systems using DPNN. In the result, we can see that the modelling and control using DPNN work well by computer simulation.

• Journal of Power Electronics
• /
• v.19 no.1
• /
• pp.190-200
• /
• 2019

The flyback converter, which can be regarded as a nonlinear time-varying system, has complex dynamics and nonlinear behaviors. These phenomena can affect the stability of the converter. To simplify the modeling process and retain the information of the output capacitor branch, a special sampled-data model of a peak current-mode (PCM) controlled flyback converter is established in this paper. Based on this, its dynamic behaviors are analyzed, which provides guidance for designing the circuit parameters of the converter. With the critical stability boundary equation derived by a Jacobian matrix, the stable operation range with a varied output capacitor, proportional coefficient of error the amplifier, input voltage, reference voltage and slope of the compensation ramp of a PCM controlled flyback converter are investigated in detail. Research results show that the duty ratio should be less than 0.5 for a PCM controlled flyback converter without ramp compensation to operate in a stable state. The stability regions in the parameter space between the output capacitor and the proportional coefficient of the error amplifier are enlarged by increasing the input voltage or by decreasing the reference voltage. Furthermore, the ramp compensation also can extend to the stable region. Finally, time-domain simulations and experimental results are presented to verify the theoretical analysis results.

• Proceedings of the KIEE Conference
• /
• 1999.07b
• /
• pp.749-751
• /
• 1999

We acquired operating data in an existing steam turbine power plant using analog control system to investigate operation characteristics. We analyzed a load control logic to develop a digital turbine control system. The load control logic is constituted of load target, load reference, loading rate, load limit and admission mode transfer of valve. The result of this paper is utilized to implement a digital turbine control system.

• Journal of Auto-vehicle Safety Association
• /
• v.5 no.1
• /
• pp.16-24
• /
• 2013

Some GM (General Motors) vehicles are using a GMLAN (General Motors Local Area Network) communication protocol for control and diagnostics. The airbag control module uses vehicle speed information from the GMLAN to record the vehicle speed as pre-crash information. In order to use the vehicle speed information for crash reconstruction purposes, it helps to be able to understand the accuracy of the data. The actual vehicle speed is not expected to be the same as the GMLAN indicated speed in some situations like a spin or if there is hard braking. This paper compares the actual vehicle speed and vehicle speed information during specific vehicle maneuvers. Actual vehicle speed is calculated from a GPS sensor, while GMLAN vehicle speed is calculated from transmission output sensor by the Engine control module (ECM). Vehicle maneuvers defined as Mode #1, Mode #2, Mode #3. The Mode #1 maneuver simulates wheel lock-up and skidding f by hard-braking at a specific speed. The Mode #2 maneuver simulates a 90degree turn using a J-turn maneuver at a specific speed. The Mode#3 maneuver simulates a 180 degree turn using a spin type of maneuver at a specific speed. The study then compares the GMLAN speed and GPS speed to see what speed difference exists between them. The results of this paper are applicable to GM vehicles only. This paper catalogs the performance and limitations of two vehicles as useful reference for crash reconstructions where there is a need to understand the speed indicated in the pre-crash section of the SDM data.

• The Research Journal of the Costume Culture
• /
• v.19 no.3
• /
• pp.518-530
• /
• 2011

Based on the development of digital technology, Photoshop as a computer graphics program has extended its range of application to creative techniques that can express the contemporary sense of fashion illustration. Thus, the objectives of this study are to seek a new technique of fashion illustration through a study of computer graphics programs required for vitalization in this digital era and to present the application. This is done after a literature review and empirical investigation. For the literature review, specialty publications with precedent studies related to the subject of this study are examined, and internet materials with related key words are sought to establish the reference data for the study. For the empirical investigation, cases of each expression for blending mode are examined to seek the correct means of fashion illustration. Five works are created as a result. The specific contents of this study are as follows: First, the types and characteristics of blending mode are examined. Second, cases in which the blending mode is applied are analyzed to seek insight into their utilization. Third, five works are created by applying the blending mode to present the result.

• Structural Engineering and Mechanics
• /
• v.41 no.5
• /
• pp.663-673
• /
• 2012

A number of mode shape-based structure damage identification methods have been verified by numerical simulations or experiments for on-line structure health monitoring (SHM). However, many of them need a baseline mode shape generated by the healthy structure serving as a reference to identify damages. Otherwise these methods can hardly perform well when multiple cracks conditions occur. So it is important to solve the problems above. By aid of the fractal dimension method (FD), Qiao and Wang proposed a generalized fractal dimension (GFD) to detect the delamination damage. As a modification of GFD, Qiao and Cao proposed the approximate waveform capacity dimension (AWCD) technique to simplify the calculation of fractal and overcome the false peak appearing in the high mode shapes. Based on their valued work, this paper combined and applied the AWCD method and curvature mode shape data to detect multiple damages in beam. In the end, the identification properties of the AWCD for multiple damages have been verified by groups of Monte Carlo simulations and experiments.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.spc1
• /
• pp.304-309
• /
• 2006

Near infrared reflectance spectroscopy (NIRS) was used to develop a rapid and nondestructive method for the determination of fatty acid composition in sesame (Sesamum indicum L.) seed oil. A total of ninety-three samples of intact seeds were scanned in the reflectance mode of a scanning monochromator, and reference values for fatty acid composition were measured by gas-liquid chromatography. Calibration equations were developed using modified partial least square regression with internal cross validation (n=63). The equations obtained had low standard errors of cross-validation and moderate $R^2$ (coefficient of determination in calibration). Prediction of an external validation set (n=30) showed significant correlation between reference values and NIRS estimated values based on the SEP (standard error of prediction), $r^2$ (coefficient of determination in prediction) and the ratio of standard deviation (SD) of reference data to SEP. The models developed in this study had relatively higher values (more than 2.0) of SD/SEP(C) for oleic and linoleic acid, having good correlation between reference and NIRS estimate. The results indicated that NIRS, a nondestructive screening method could be used to rapidly determine fatty acid composition in sesame seeds in the breeding programs for high quality sesame oil.