• The Journal of Engineering Geology
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• v.24 no.1
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• pp.53-67
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• 2014

Numerical modeling is commonly used to reproduce the physical phenomena of dam-break and to compile resulting flood hazard maps. The accuracy of a dam-break model depends on the physical structure that describes the volume of storage, breach formation and progress, input variables, and model parameters. Model input and parameters are subjective in that they are prescribed; hence, caution is needed when interpreting the results. This study focuses on three parameters (breach degree ${\theta}$, shape factor P, and collapse rate k) used when the dam-break model is coupled with FLO-2D (a two-dimensional flood simulation model) to estimate flood coverage and depth etc. The results show that the simulation is sensitive to the shape factor P and the collapse rate k but not to the breach degree ${\theta}$. This study will contribute to reducing flood damage from dam-break disasters in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1899-1909
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• 2007

A cross-coupled charge pump with internal pumping capacitor, witch is advantages from a point of minimizing TFT-LCD driver IC module, is newly proposed in this paper. By using a NMOS and a PMOS diode connected to boosting node from VIN node, the pumping node is precharged to the same value each pumping node at start pumping operation. Since the lust-stage charge pump is designed differently from the other stage pumps, a back current of pumped charge from charge pumping node to input stage is prevented. As a pumping clock driver is located the font side of pumping capacitor, the driving capacity is improved by reducing a voltage drop of the pumping clock line from parasitic resistor. Finally, a layout area is decreased more compared with conventional cross-coupled charge pump by using a stack-MIM capacitors. A proposed charge pump for TFT-LCD driver IC is designed with $0.13{\mu}m$ triple-well DDI process, fabricated, and tested.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.3
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• pp.34-40
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• 2002

In this paper, a new encryption method for a binary image using Phase modulation and Fourier transform is proposed. For decryption we use the characteristics of square law detector. In encryption process, a key image is obtained by phase modulation of 256 level random pattern and its Fourier transformation, and input image is encrypted by Fourier transforming the multiplication of the phase modulated random pattern and phase modulated input image. The encrypted image and key image have only phase information, so they can not be copied or counterfeited and the original image can not be decrypted without the key image. To reconstruct the original image, each phase mask of the key image and the encrypted image must be placed on each path of the Mach-Zehnder interferometry with Fourier transform lens and the output image is obtained in the form of intensity in the CCD(Charge Coupled Device) camera. The real-time decryption is possible in the proposed system by use of a LCD as a phase modulator and a CCD camera as an intensity detector. The proposed method shows a good performance in the computer simulation and optical experiment as an encryption scheme.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.7 s.98
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• pp.681-689
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• 2005

This paper presents an ultra wide band(UWB) mixer using anti-parallel diode pair(APDP) with simulation and measurement results. The proposed mixer adopts the even-harmonic direct conversion mixing, which consists of a couple of filter, in-phase wilkinson power divider, wideband $45^{\circ}$ power divider, and APDP. The m mixer is operating over 3.1 to 4.8 GHz and producing quadrature(I/Q) outputs with a conversion loss of 18 dB and input third order intercept point($IIP_3$) of 15 dBm. I/Q outputs also have difference of about 0.5 dB and phase difference of ${\times}3^{\circ}$ and $P_{1dB}$ of 2 dBm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.3
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• pp.34-39
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• 1999

Electron temperature and electron density were rreasured in a radio-frequency inductively coupled plasma (RFICP) using a Langmuir probe method. Measurerrent was conducted in an argon discharge for pressures from 10 mTorr to 40 mTorr and input rf rnwer from 100 W to 600 W. Spatial distribution electroo temperature and electron density were rreasured for discharge with satre aspect ratio (R/L=2). Electron temperature and electron density were discovered depending on both pressure and power. Electron density was increased with iocreasing input power, but saturated at 450 W. Electron density was iocreased with iocreasing pressure. Radial distribution of the electron density was peaked at the rnsition which was a little rmved from center toward quartz window. Normal distribution of the electron density was peaked in the center between quartz plate and substrate. The above results could contribute to understand the Mechanism of Radio-Frequency Inductively Discharge Plasma.Plasma.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.869-879
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• 1995

The new field of learning control develops controllers that learn to improve their performance at executing a given task, based on experience performing this task. The simplest forms of learning control are based on the same concept as integral control, but operating in the domain of the repetitions of the task. In the previous paper, I had studied the use of such controllers in a decentralized system, such as a robot with the controller for each link acting independently. The basic result of the paper is to show that stability of the learning controllers for all subsystems when the coupling between subsystems is turned off, assures stability of the decentralized learning in the coupled system, provided that the sample time in the digital learning controller is sufficiently short. In this paper, we present two examples. The first illustrates the effect of coupling between subsystems in the system dynamics, and the second studies the application of decentralized learning control to robot problems. The latter example illustrates the application of decentralized learning control to nonlinear systems, and also studies the effect of the coupling between subsystems introduced in the input matrix by the discretization of the system equations. The conclusion is that for sufficiently small learning gain, and sufficiently small sample time, the simple learning control law based on integral control applied to each robot axis will produce zero tracking error in spite o the dynamic coupling in the robot equations. Of course, the results of this paper have much more general application than just to the robotics tracking problem. Convergence in decentralized systems is seen to depend only on the input and output matrices, provided the sample time is suffiently small.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.415-421
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• 2015

Ca is material to used in Chinese cabbage (Brasica rapa L. spp. pekinensis). The variation of inorganic ions and GSLs in Chinese cabbage cultivated to control additional Ca contents in slaked lime. The additional fertilizer of slaked lime differ four grade that 0 g (Ca-0), 0.28 g (Ca-1), 0.56 g (Ca-2), 0.84 g (Ca-3) are week intervals with a total of 8 times after transplanting. Inorganic ions in Chinese cabbage ('Bulam plus') were analyzed to use inductively coupled plasma atomic emission spectometry(ICP). The more additional slaked lime input, the more almost macronutrients contents were high except Ca. Ca contents were higher in Ca-0 (153.10) and lower in Ca-3 (130.55 mg/kg dry weight, DW). GSLs were identified based on peak retention time in previous results of our laboratory. Seven GSLs including two aliphatic (gluconapin, glucobrassicanapin), one aromatic (gluconasturtiin), four indolyl (glucobrassicin, neoglucobrassicin, 4-methoxyglucobrassicin, 4-hydroxyglucobrassicin) were detected using HPLC. Progoitrin, 4-methoxyglucobrassicin, and gluconasturtiin contents increased in proportion to the input in additional slaked lime. Total GSLs contents were Ca-0 (11.95), Ca-1 (17.02), Ca-2 (19.63), Ca-3 ($17.11{\mu}mol/g$ dry weight, DW). Total Ca and GSLs contents (Ca-1,2,3; mean 17.92) are higher than non treatment (Ca-0; $11.95{\mu}mol/g$ DW).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.6
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• pp.26-33
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• 2002

In this paper, a new four-quadrant MOS analog multiplier Is proposed using the quarter-square technique, which is based on the quadratic characteristics of MOS transistor operating in the saturation region and the difference operation of a source-coupled differential circuits. The proposed circuit has been fabricated in a p-well CMOS process. The multiplier achieves a total harmonic distortion of less than 1 percent for the both input ranges of 50 percent of power supply, a -3㏈ bandwidth of 30㎒ a dynamic range of 81㏈ and a power consumption of 40㎽. The active chip area is 0.54㎟. The supposed multiplier circuit is simple and adjust high frequency application because one input signal transfer output by one transistor.

• Fire Science and Engineering
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• v.33 no.4
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• pp.50-58
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• 2019

The prediction performance of B-RISK was evaluated for the fire behaviors of combustibles in a compartment using Fire Dynamics Simulator (FDS). First of all, to predict the heat release rate (HRR) for two combustible sets, the HRR for one combustible set and the design fire curve were used as input values for B-RISK. Comparing results of B-RISK calculations with experimental data for two combustible sets, it was found that B-RISK results predicted insufficiently for fire growth rate of experimental data but there was good agreement for maximum HRR and total HRR with the experimental data. And the B-RISK results were used for input values of FDS to evaluate the fire behaviors of B-RISK results. Comparing results of FDS calculations with experimental data, the simulation results showed that the temperature and concentrations of O₂, CO₂ in the fire growth phase were different from the experimental data. However, when using the B-RISK result for percentile 70%, the simulation results sufficiently predicted the overall fire behaviors.

• Coupled systems mechanics
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• v.9 no.2
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• pp.111-123
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• 2020

Wastewater treatment plants (WWTPs) with activated sludge system are widely used throughout the most common technologies in the world. Most treatment plants require optimization of certain treatment processes using dynamic modeling. A lot of examples of dynamic simulations require reliable data base of diurnal variation of the inflow and typical concentrations of parameters such as Chemical Oxygen Demand (COD), Total Kjeldahl Nitrogen (TKN), etc. Such detailed data are not available, which leads to problemsin the application of dynamic simulations. In many examples of plants, continuous flow measurements are only performed after the primary clarifier, whereas measurements from influent to the plant are missing, as is the case with the examples in this paper. In some cases, a simpler, faster and cheaper way can be applied to determine influent variations, such as the "HSG-Sim" method ("Hochschulgruppe Simulation"). "Hochschulgruppe Simulation" is a group of researchers from Germany, Austria, Switzerland, Luxembourg, Netherlands and Poland (see http://www.hsgsim.org). This paper presents a model for generating daily variations of inflow and concentration of municipal wastewater quality parameters, applied to several existing WWTPs in Bosnia and Herzegovina (B&H). The main goal of the applied method is to generate realistic influent data of the existing plants in B&H, in terms of flow and quality, without any prior comprehensive survey and measurements at the site. The examples of plants show the influence of overflow facilities on the dynamics of input flow and quality of wastewater, and a strong influence of the problems of the sewerage systems.