• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.5
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• pp.226-230
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• 2003

When an excessive voltage is applied to the discharge gap in ozone generator, the discharge room temperature becomes higher. As is well own, the efficiency of the ozone generation is deteriorated by the excessively hot temperature because of the decomposition reaction. In this paper, the simple small capacity ozone generating controller has been introduced, which provides effective and stable silent discharge characteristics over wide range input power. The proposed power controller has two important advantages, which imply that the production rate of ozone can be controlled linearly according to the delivered power and the surplus energy is recovered to the source. The experimental results are given to verify the performance of the pre proposed controller.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1704-1706
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• 2003

Low-Pressure inductively coupled RF discharge sources have important industrial applications mainly because they can provide a high-density electrodeless plasma source with low ion energy and low power loss. In an inductive discharge, the RF power is coupled to the plasma by an electromagnetic interaction with the current flowing in a coil. In this paper, the experiments have been focussed on the electric characteristic and carried out using a single Langmuir probe. The internal electric characteristics of inductively coupled Ar RF discharge at 13.56 [MHz] have been measured over a wide range of power at gas pressure ranging from $1{\sim}70$ [mTorr].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.841-846
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• 2014

It found that the maximum temperature of the arc discharge occurred on the Silicone rubber sample significantly decreased with increasing the reinforcing agent. It was confirmed that the current value decreased with increasing the aluminium trihydrate($Al(OH)_3$) and the current value increased with reducing the primary resistance over time. Regarding these results, may be it is because the degradation due to the electro-conductive carbonization was improved and the properties of dielectric breakdown was reduced by the flame retardant reinforcing agent. It found that the electro-conductive carbonized road has not happened by increasing the flame retardant reinforcing agent. Regarding to the arc discharge, this study show that the arc arising near the lower electrode of sample has disappeared.

• Bulletin of the Korean Chemical Society
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• v.15 no.1
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• pp.23-25
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• 1994

A simple analytical method that allows direct monitoring of small amount of CO$_2$ in a CO$_2$ discharge tube which utilizes the optoacoustic detection technique is described. The dependence of the optoacoustic signal on the mole fraction of CO$_2$ was shown that the system responded linearly to the amount of CO$_2$ present in the miniature discharge cavity equipped with Cu electrodes. It was also found that fraction of dissociated CO$_2$ varied from 14 to 37% of the initial concentration which depended on the current and the pressure in the tube. This simple and easy detection method has proven to possess the practical advantages over the conventional systems for the study of CO$_2$ laser electrodes.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.138-138
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• 2022

Understanding a stream's or river's discharge is essential for a variety of hydrological and geomorphological applications at various sizes. However, depending on the stream environment and flow conditions, it is crucial to use the appropriate techniques and instruments. This will ensure that discharge estimations are as reliable as possible. This study presents developed smart system for continuous measurement of open channel discharge and evaluate streamflow measurement over various techniques. This includes developed smart flow meter as flow point measurements, smart water level sensor (installed on Hydraulic Structure ? Weir) and current meters. Advantages and disadvantages of each equipment are presented to ensure that the most appropriate method can be selected. we found that smart water level sensor is more prominent once used during flood event as compared to smart flow meter and current meters, while current meters seems to show better accuracy once applied for open channel.

• Journal of Korean Academy of Nursing
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• v.24 no.1
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• pp.18-32
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• 1994

It is important to understand that patients with hemiplegia are under stress during the rehabilitation process. This study was designed to determine what changes occur in the stress perceived by these patients during the rehabilitation process. and what changes occur in the ways they coped with stress. A decriptive study with a longitudinal design was conducted. A total of 57 patients with hemiplegia who were admitted to one general hospital made up the sample for this study. A questionnaire, observations and interviews were used for the data collection which was done in three phases(within one week after admission : within one week before discharge ; within one month after discharge ). Data were analyzed using t-test, ANOVA repeated measures of ANOVA, and post hoc paired t -test, Bonferroni correction. The results of this study are : 1. Changes in the perception of stress during the rehabilitation process : There was a statistically significant differencs in the perception of stress among these patients during the rehabilitation process. On the post-hoc test. the perception of stress showed a statistically significant decrease from admission to discharge. The perception of psychological stress was high during the rehabilitation process as compared with the perception of physical and social stress. 2. Changes in the way the patients coped during the rehabilitation process : On admission passive coping was used by most of the subjects(91.2％). Passive coping showed an decrease from admission to discharge, but an increase from discharge to follow-up at one month post discharge. There was, however, no statistically significant changes in the way the patients coped during the rehabilitation process. 3. Changes in perception of stress during the rehabilitation process according to variables. Perception of stress among patients classified as So-Um was higher during the rehabilitation process, when compared with patients classified as So- Yang and Tae-Um. There was, however, no statistically significant difference in perception of stress over time. The patients with right sided paralysis perceived higher stress than those with left sided paralysis. There was, however, no statistically significant difference in perception of stress over time. Hence, stress was not influenced by which side was paralyzed th frequency of the relapse of the disease, or the time in the rehabilitation process. 4. Changes in coping during the rehabilitation process according to variables. There was a statistically significant difference in the way the patients coped at follow- up according to the three different kinds of the constitution groups. In other words, coping was not used by patients classified as Tae-Um but was used by those classified as So-Um. On the repeated measures of ANOVA, there was a statstically significant difference in stress over time, and an interaction between constitution and time. But the way of coping during the rehabilitation process was not influenced by which side was paralyzed nor by the frequency of the relapse of the disease. In conclusion, perception of psychological stress was high during the rehabilitation process, as compared to perception of physical and social stress. There was a statistcally significant difference in the perception of stress over time, Perception of stress showed a gradual decrease from over admission to follow-up period. There was. however, no statistically significant difference in the way of coping over time. Passive coping was used by most of patients. In the study, these findings suggest a need for nursing care related to the psychological support for patients with hemiplegia both in the hospital as well as at home, and the need for education and counseling on independent self-care to help the hemiplegic patients adapt to stress using active coping.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.6
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• pp.387-396
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• 2010

A 3-D numeric model for the confined transient flow under sea ground have been developed. This is FDM model using Gauss-Seidel SOR (successive over-relaxation). This model shows the similar head distribution pattern to Theis analytic solution and MODFLOW simulation. The input flowrate to the aquifer and discharge of well have been compared. And it have been found that mass balance is influenced by the weight factor ${\alpha}$, i.e. fullyimplicit method (${\alpha}$=1) shows 5% error, but when ${\alpha}$ becomes to 0.5(Crank and Nicolson method) the mass balance becomes worse and the model result diverges. And the convergency of the model is not much different when $\lambda$ (over-relaxation factor)=0.8~1.5, but when $\lambda$>1.5, the model result diverges. The test-run shows that the well discharge becomes smaller when another well is near. This model can cover the isotropy$(Kx{\neq}Ky{\neq}Kz)$ and inhomogeneity, and can be used for the selection of well site, discharge calculation, and head prediction in case of the artificial recharge etc.

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.209-220
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• 2015

In this study, the effects of changed environment on spatial extension of flood discharge data which is generating discharge data at ungauged watersheds. Especially, effects of dams on spatial extensions of flood discharge data and on natural flow generation were studied. This is somehow an intial trial of flood discharge data generation for heterogeneous watersheds because of dam installation. Data extensions have been performed based on the flood discharge data from YeoJoo water gauge station located on the Nam-Han River. For the evaluation of flood discharge data spatial extension under dam effects and producing natural flow, 41 flood events associated with YeoJoo water gauge station were selected from 1986 to 2010. When flood discharge data were extended based on YeoJoo water gauge station, 77% of selected flood events were over the satisfaction ranges (NSE>0.5) of Nash-Sutcliffe Efficiency for model validation. Extended flood discharge data at Yangpyung has 0.84 NSE obtained from spatial data extension based on YeoJoo water gauge station. Generated natural flow at YeoJoo was influenced strongly by Chungju Dam which has larger effects on streamflow at YeoJoo than Hoangsung Dam. Observed peak discharges after the 1986 of Chungju Dam installation were smaller than those of the obtained natural flow. Through these results, spatial extension of flood discharge data with installed dams works efficiently for ungauged watersheds and natural flow can be generated using extended flood discharge data.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.268-280
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• 2009

Oncheon basin which are located in Busan is divided into 43 basin on the basis of main pipe, constructed with Storm Water Management Model (SWMM). Occurrence situation for Outflow and pollutant loads by long-term continuous rainfall is examined for treatment district and river analysis point of Oncheon basin and a reduction vs effectiveness table for effective CSOs managements is made for each of treatment districts according to each of managements. In case that treatment equipment is located at the discharge point of CSO, treatment efficiency is analysed. It is supposed that treatment equipment have an efficiency on the basis of a concentration and runoff discharge over a critical flow is discharged with it untreated and treating runoff discharge with treatment equipment at each of runoff discharge points and treating it gathered at sewage treatment plant (STP) through trunk sewer is compared for a relative treatment efficiency.

• Journal of the Korean Geosynthetics Society
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• v.7 no.2
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• pp.15-21
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• 2008

The advantages of prefabricated vertical drains over conventional sand drains include their relatively low costs, less disturbance to the soil mass, the easinees of installation, and their flexibility which ensures the integrity of the drains during installation. This study tested the change of discharge capacities with respect to the hydraulic gradients for each lateral pressure. From the test results, as increases the overburden pressure, the clay soil is being consolidated, and also lateral pressure to the PVD specimen is increased. Therefore, the discharge capacity is decreased. The size of opening space in the core of PVDs is proportionally related to the discharge capacity. The numerical analysis was performed with utilizing computer simulation with considering field conditions. The results of numerical analysis are compared well with the field measurements.