• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.67-75
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• 2014

In this study, the large-scale hydraulic model test was performed to investigate the hydraulic characteristics for development of the non-power soil cleaning and keeping system at the dike gate. The outlet height, outflow number, outflow discharge, and outflow cycle were compared and analyzed. The non-power soil cleaning and keeping system was most effective at 11.2 mm in the outlet height. And then the mean outflow cycle was 1.09 sec, and the mean outflow discharge was $0.00164m^3/s$. The total outflow number increased gradually as the water level of a water tank increased, and the outlet height decreased. As a level of water tank decreased, the mean outflow cycle was lengthened, and the unit outflow discharge increased. This result showed this system was most effective. To remove the silty clay deposited in facilities, the methods of excavation, dredging, high pressure washing, etc have been applied to the tidal facilities such as land reclamation, a small size fishing port, and a harbor for maintenance. However, this is extremely cost-ineffective, whereas the non-power soil cleaning and keeping system will bring about an enormously positive economic effect. In addition, when the non-power soil cleaning and keeping system is applied to the dike gate of land reclamation, a thorough examination of the local tidal data and the careful system planning are required to prevent the disaster damage caused by flooding.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1281-1282
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• 2005

• Journal of Korea Water Resources Association
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• v.48 no.1
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• pp.45-55
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• 2015

In this study, when seawall or harbor gate is installed for coastal disaster prevention, a two-dimensional water analysis in the bay is carried out to consider the flood amount of river inflow and effect of harbor gate. The Yeongsan river and the port Mokpo area are selcected for the study region. Then, by analyzing the hydraulic characteristics of flood flow of the Yeongsan river, we analysed the compatibility of the results in the two-dimensional hydrodynamic model. A tw-odimensional water analysis were conducted for the four cases considering whether a harbor gate is installed or not, and whether the inland water boundary condition is considered or not, also with open sea boundary condition. The results of the two-dimensional water analysis shows that water level change near the port Mokpo area is mainly caused by the discharge of the estuary barrage of the Yeongsan river because the harbor gate was installed. In addition, it is revealed that the volume of reservoir created by the harbor gate and the estuary barrage is too much small compared to the volume of the discharge from the Yeongsan river. Therefore, when the harbor gate is installed in the open sea, we concluded that a flexible management between the harbor gate and the estuary barrage of the Yeongsan river is required. A initial water level of the bay and outflow from the harbor gate are proposed for disaster prevention in the coastal area of port Mokpo.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.6
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• pp.31-38
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• 2016

The purpose of this study was to assess nonpoint sources (NPS) pollution affected by liquid manure and regulating gate in a small agricultural watershed. The study area, which is a wide plain farmland, was operating by the Buyong regulating gate in order to maintain irrigation water level during irrigation period. Consequentially, runoff only occurs through the gate at each event in rainy season for avoiding farmland inundation. In addition, the usage ratio of liquid manure in the study area has been increased greatly since 2014. Discharge loads at the Hwaingsan bridge subwatershed were 1.2 times for T-N, 4-10 times for T-P, and 3-8 times for TOC compared with the Soyang watershed (control) during study period. The reason was that NPS pollutants from upper Gpeun and Sangri bridge subwatersheds, which are widely spraying with livestock liquid manure, were stack at this subwaterehd because of regulating gate in non-rainy seasons. A number of agricultural watersheds in Saemangeum watershed are affected by regulating gate and vigorous livestock activities so that substantial management schemes under controling regulating gate are needed for minimizing livestock related NPS.

• Journal of Korea Water Resources Association
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• v.51 no.8
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• pp.687-701
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• 2018

A multi-function weir is representative control structure in the stream flow. Estimation of accurate flood discharge according to gate operations and prediction of floodwave travel times at the downstream are very important in terms of water use and river management. This study analyzed the limitation and improvement through the current gate operation data on the Young-san river. in addition, flood discharge was calculated considering lower and upper water level condition and gate operating using the modified slope-area method in the Seoung-chon weir. As a result, the current state was required improvement because exceed the theoretical range and rapidly fluctuation of discharge coefficient, can not be considered difference between the upper and lower water level and the estimation by the regression equation. As a result of applying the proposed method in this study, the above mentioned limitations can be compensated, compared with the current discharge data. Also it was analyzed as more physically valid because using the evaluated hydraulic equation and estimate the slope and friction loss of natural stream by iteration and to reduce the error. In conclusion, the process carried out serves as a representative flow control point of the water system through reliable discharge estimation, it is expected that it will be possible to properly river management.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.3-4
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• 2009

As device process technology advances, effective channel length, the thickness of gate oxide, and supply voltage decreases. This paper describes a novel electrostatic discharge (ESD) protection device which has current feedback for high ESD immunity. A conventional Gate-Grounded NMOS (GGNMOS) transistor has only one ESD current path, which makes, the core circuit be in the safe region, so an GGNMOS transistor has low current immunity compared with our device which has current feedback path. To simulate our device, we use conventional $0.18\;{\mu}m$ technology parameters with a gate oxide thickness of $43\;{\AA}$ and power supply voltage of 1.8 V. Our simulation results indicate that the area of our ESD protection, device can be smaller than a GGNMOS transistor, and ESD immunity is better than a GGNMOS transistor.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.36-43
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• 2013

In this study, the high current behaviors and double snapback mechanism of gate grounded_extended drain n-type MOSFET(GG_EDNMOS) device were analyzed in order to realize the robust electrostatic discharge(ESD) protection performances of high voltage operating display driver IC(DDIC) chips. Both the transmission line pulse(TLP) data and the thermal incorporated 2-dimensional simulation analysis as a function of ion implant conditions demonstrate a characteristic double snapback phenomenon after triggering of bipolar junction transistor(BJT) operation. Also, the background carrier density is proven to be a critical factor to affect the high current behavior of the GG_EDNMOS devices.

• Water for future
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• v.22 no.1
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• pp.91-98
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• 1989

This study was aimed to determine a discharge coefficient of flow through gate piers. The coefficient was Calbrated with water stage data observed during 1984 to 1987 at the Young San Estuary Dam. The coefficient is the function of the dimensionless parameters combined with the difference between up and down stream water level to down stream water depth ratio and water surface draw down ratio. From the verification with existing methods and actual drainages, drainages predicted by the relationship have the most consistency with the actual drainages, also Matthai's method can be used within the proposed condition originally.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1716-1717
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• 2008

The spillway gate is the most important facility of the multi-purpose dam. we usually use various sensor and conversion technique to control the gate. In this study, we mathematically analyze the instrumental errors on the different winch types. And we will briefly explain the measurement methods used on a gauge for a spillway gate and the calculation method of the discharge water volume.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.105-105
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• 2012

We have developed a photoemission-assisted plasma-enhanced chemical vapor deposition (PAPE-CVD) [1,2], in which photoelectrons emitting from the substrate surface irradiated with UV light ($h{\nu}$=7.2 eV) from a Xe excimer lamp are utilized as a trigger for generating DC discharge plasma as depicted in Fig. 1. As a result, photoemission-assisted plasma can appear just above the substrate surface with a limited interval between the substrate and the electrode (~10 mm), enabling us to suppress effectively the unintended deposition of soot on the chamber walls, to increase the deposition rate, and to decrease drastically the electric power consumption. In case of the deposition of DLC gate insulator films for the top-gate graphene channel FET, plasma discharge power is reduced down to as low as 0.01W, giving rise to decrease significantly the plasma-induced damage on the graphene channel [3]. In addition, DLC thickness can be precisely controlled in an atomic scale and dielectric constant is also changed from low ${\kappa}$ for the passivation layer to high ${\kappa}$ for the gate insulator. On the other hand, negative electron affinity (NEA) of a hydrogen-terminated diamond surface is attractive and of practical importance for PAPECVD, because the diamond surface under PAPE-CVD with H2-diluted (about 1%) CH4 gas is exposed to a lot of hydrogen radicals and therefore can perform as a high-efficiency electron emitter due to NEA. In fact, we observed a large change of discharge current between with and without hydrogen termination. It is noted that photoelectrons are emitted from the SiO2 (350 nm)/Si interface with 7.2-eV UV light, making it possible to grow few-layer graphene on the thick SiO2 surface with no transition layer of amorphous carbon by means of PAPE-CVD without any metal catalyst.