• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제13권4호
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• pp.82-86
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• 1999

Electron Energy Distribution Function(EEDF) were treasured In Radio-Frequency Inductively Coupled Plasma(RFlCP) using a probe rrethocl Measurerrents were conducted in argon discharge for pressure from 10[mTorr] to 4O[mTorr] and input rf power from 100[W] to 600[W] and flow rate from 3[sccm] to 12[sccm]. Spatial distribution of electron energy distribution function were measured for discharge with same aspoct ratio (R/L=2). Electron energy distribution function strongly depended on both pressure and power. Electron energy distribution function increased with increasing flow rate. Radial distribution of the electron energy distribution function were peaked in the plasma center. Normal distribution of the electron energy distribution function were peaked in the center between quartz plate and substrate. From the results, we can find out the generation mechanism of Radio Frequency Inductively Coupled Plasma. And these results contribute the application of a simple Inductively Coupled Plasma(ICP).a(ICP).

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2018년도 학술발표회
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• pp.155-155
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• 2018

Uncertainty in flood forecasting using a coupled meteorological and hydrological model is arisen from various sources, especially the uncertainty comes from the inaccuracy of Quantitative Precipitation Forecasts (QPFs). In order to improve the capability of flood forecast, the uncertainty estimation and mitigation are required to perform. This study is conducted to investigate and reduce such uncertainty. First, ensemble QPFs are generated by using Monte - Carlo simulation, then each ensemble member is forced as input for a hydrological model to obtain ensemble streamflow prediction. Likelihood measures are evaluated to identify feasible member. These members are retained to define upper and lower limits of the uncertainty interval and assess the uncertainty. To mitigate the uncertainty for very short lead time, a blending method, which merges the ensemble QPFs with radar-based rainfall prediction considering both qualitative and quantitative skills, is proposed. Finally, blending bias ratios, which are estimated from previous time step, are used to update the members over total lead time. The proposed method is verified for the two flood events in 2013 and 2016 in the Yeonguol and Soyang watersheds that are located in the Han River basin, South Korea. The uncertainty in flood forecasting using a coupled Local Data Assimilation and Prediction System (LDAPS) and Sejong University Rainfall - Runoff (SURR) model is investigated and then mitigated by blending the generated ensemble LDAPS members with radar-based rainfall prediction that uses McGill algorithm for precipitation nowcasting by Lagrangian extrapolation (MAPLE). The results show that the uncertainty of flood forecasting using the coupled model increases when the lead time is longer. The mitigation method indicates its effectiveness for mitigating the uncertainty with the increases of the percentage of feasible member (POFM) and the ratio of the number of observations that fall into the uncertainty interval (p-factor).

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• 제10권6호
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• pp.558-569
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• 2017

In this paper, a 256Kb EEPROM IP aimed at battery applications using a single supply of 1.5V which is embedded into an MCU is designed. In the conventional cross-coupled VPP (boosted voltage) charge pump using a body-potential biasing circuit, cross-coupled PMOS devices of 5V in it can be broken by the junction or gate oxide breakdown due to a high voltage of 8.53V applied to them in exiting the program or erase mode. Since each pumping node is precharged to the input voltage of the pumping stage at the same time that the output node is precharged to VDD in the cross-coupled charge pump, a high voltage of above 5.5V is prevented from being applied to them and thus the breakdown does not occur. Also, all erase, even program, odd program, and all program modes are supported to reduce the times of erasing and programming 256 kilo bits of cells. Furthermore, disturbance test time is also reduced since disturbance is applied to all the 256 kilo bits of EEPROM cells at once in the cell disturb test modes to reduce the cell disturbance testing time. Lastly, a CG driver with a short disable time to meet the cycle time of 40ns in the erase-verify-read mode is newly proposed.

• Journal of IKEEE
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• 제11권1호통권20호
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• pp.61-68
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• 2007

Using modal transmission-line theory (MTLT), itexplores rigorously the polarization characteristics of TE-TM mode optical polarized beamsplitter with misaligned input interface. To verify the validity of the approach proposed in this paper, a novel polarization condition is defined, and it compares and evaluates with the polarization condition of coupled-mode theory (CMT) used widely. The numerical results reveal that the discontinuity of misaligned input interface has nothing to do with the polarization condition of beamsplitter. Furthermore, the condition of CMT is no longer effective at the asymmetric guiding structures with strong power coupling.

• Proceedings of the KIPE Conference
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.512-517
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• 1998

In a matrix converter, input side and output side are coupled with each other through switching elements. Since disturbances on either side affect directly on the other side, it requires a high-speed on-line control system to compensate them. We proposed in previous papers a new control strategy and an on-line control circuit for a matrix converter. The control circuit could keep the output voltage at commanded value against fluctuation in the supply voltage. Furthermore wave forms of the output voltage and the input current were always kept sinusoidal. The switching pattern was generated by comparing modified voltage references with a carrier. The carrier was synchronized with the supply voltage using a PLL system, which made the control circuit complicated and costly. This paper discusses on the possibility of an asynchronized carrier. Experiment results show the input current distortion in case of asynchronous carrier is bigger than that of synchronous carrier. However, the deterioration can be minimized by increased carrier frequency.

• Journal of Sensor Science and Technology
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• 제26권5호
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• pp.342-347
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• 2017

We present a precision instrument amplifier (IA) designed for bio-potential acquisition. The proposed IA employs a capacitively coupled instrument amplifier (CCIA) structure to achieve a rail-to-rail input common-mode range and low gain error. A positive feedback loop is applied to boost the input impedance. Also, DC servo loop (DSL) with pseudo resistors is adopted to suppress electrode offset for bio-potential sensing. The proposed amplifier was designed in a $0.18{\mu}m$ CMOS technology with 1.8V supply voltage. Simulation results show the integrated noise of $1.276{\mu}Vrms$ in a frequency range from 0.01 Hz to 1 KHz, 65dB SNR, 118dB CMRR, and $58M{\Omega}$ input impedance respectively. The total current of IA is $38{\mu}A$. It occupies $740{\mu}m$ by $1300{\mu}m$ including the passive on-chip low pass filter.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제21권4호
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• pp.321-328
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• 2008

In this paper, variable gain amplifier(VGA) with a gain slope controller has been proposed and verified by circuit simulations and measurements. The proposed VGA has a gain control, gain slope switch and variable gain range. The input source coupled pair with diode connected load is used for VGA gain stage. The gain slope controller with switch can control VGA gain slope. The proposed VGA is fabricated in $0.18{\mu}m$ CMOS process for multi -standard wireless receiver. The proposed two stage VGA consumes min. 2.0 mW to max. 2.6 mW in gain control range and gives input IP3 of -3.77 dBm and NF of 28.7 dB at 1.8 V power supply under -25 dBm, 1 MHz input. The proposed VGA has 37 dB(-16 dB $\sim$ 21 dB) variable gain range, and 8 dB gain range control per 0.3 V control voltage, and can provide variable gain, positive and negative gain slope control, and gain range control. This VGA characteristics provide design flexibility in multi-standard wireless receiver.

• Coupled systems mechanics
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• 제11권2호
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• pp.121-132
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• 2022

Wastewater treatment plants (WWTPs) are designed and built to remove contaminants from wastewater. WWTPs are composed of various facilities equipped with hydro-mechanical and electrical equipment. This paper presents a comparison of two different approaches for WWTPs modelling. Static modelling is suitable for determining the dimensions of facilities and equipment capacity. The special significance of this approach is for the design of new plants, i.e., when a very small number of input data on the quantities and composition of the influent wastewater is available. Dynamic modelling is expensive, time consuming and requires great expertise in the use of simulators, models and very good understanding of the treatment processes. Also, dynamic modelling is very important to use for optimization, consideration of future scenarios and also possible scenarios on the plant. The comparison of two approaches was made on the input data from the biggest and most important plant in Bosnia and Herzegovina (B&H)-WWTP Butila (Sarajevo). The main idea is to show the differences between two demanding accesses. It is important to know how to apply an adequate approach to research and solve the set task. The II phase of the plant Butila, which includes the removal of nutrients, is planned in several years and therefore the importance of research has increased.

• Coupled systems mechanics
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• 제12권5호
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• pp.429-444
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• 2023

The comprehension and structural modeling of masonry constructions is fundamental to safeguard the integrity of built cultural assets and intervene through adequate actions, especially in earthquake-prone regions. Despite the availability of several modeling strategies and modern computing power, modeling masonry remains a great challenge because of still demanding computational efforts, constraints in performing destructive or semi-destructive in-situ tests, and material uncertainties. This paper investigates the shear behavior of masonry walls by applying a plane-stress FE continuum model with the Modified Masonry-like Material (MMLM). Epistemic uncertainty affecting input parameters of the MMLM is considered in a probabilistic framework. After appointing a suitable probability density function to input quantities according to prior engineering knowledge, uncertainties are propagated to outputs relying on gPCE-based surrogate models to considerably speed up the forward problem-solving. The sensitivity of the response to input parameters is evaluated through the computation of Sobol' indices pointing out the parameters more worthy to be further investigated, when dealing with the seismic assessment of masonry buildings. Finally, masonry mechanical properties are calibrated in a probabilistic setting with the Bayesian approach to the inverse problem based on the available measurements obtained from the experimental load-displacement curves provided by shear compression in-situ tests.

• Fire Science and Engineering
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• 제27권6호
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• pp.77-82
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• 2013

This research suggested smart fire recognition system which trances firing location with CCD camera with wired/wire-less TCP/IP function and Pan/Tilt function, delivers information in real time to android system installed by smart mobile communication system and controls fire and disaster remotely. To embody suggested method, firstly, algorithm which applies hue saturation intensity (HSI) Transform for input video, eliminates surrounding lightness and unnecessary videos and segmentalized only firing videos was suggested. Secondly, Pan/Tilt function traces accurate location of firing for proper control of firing. Thirdly, android communication system installed by mobile function confirms firing state and controls it. To confirm the suggested method, 10 firing videos were input and experiment was conducted. As the result, all of 10 videos segmentalized firing sector and traced all of firing locations.