• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.5
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• pp.220-229
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• 2004

We have examined a technique of one-dimensional (1D) fluid modeling for radio-frequency Ar capacitively coupled plasmas (CCP) between unequal-sized powered and grounded electrodes. In order to simulate a practical CCP reactor configuration with a grounded side wall by the 1D model, it has been assumed that the discharge space has a conic frustum shape; the grounded electrode is larger than the powered one and the discharge space expands with the distance from the powered electrode. In this paper, we focus on how much a 1D model can approximate a 2D model and evaluate their comparisons. The plasma density calculated by the 1D model has been compared with that by a two-dimensional (2D) fluid model, and a qualitative agreement between them has been obtained. In addition, 1D and 2D calculation results for another reactor configuration with equal-sized electrodes have also been presented together for comparison. In the discussion, four CCP models, which are 1D and 2D models with symmetric and asymmetric geometries, are compared with each other and the DC self-bias voltage has been focused on as a characteristic property that reflects the unequal electrode surface areas. Reactor configuration and experimental parameters, which the self-bias depends on, have been investigated to develop the ID modeling for reactor geometry with unequal-sized electrodes.

• Journal of Environmental Science International
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• v.26 no.9
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• pp.999-1011
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• 2017

In this study, the Chiu-2D velocity-flow rate distribution based on theoretical background of the entropy probability method was applied to actual ADCP measurement data of Gangjung Stream in Jeju from July 2011 to June 2015 to predict the parameter that take part in velocity distribution of the stream. In addition, surface velocity measured by SIV (Surface Image Velocimeter) was applied to the predicted parameter to calculate discharge. Calculated discharge was compared with observed discharge of ADCP observed during the same time to analyze propriety and applicability of depth of water velocity average conversion factor. To check applicability of the predicted stream parameter, surface velocity and discharge were calculated using SIV and compared with velocity and flow based on ADCP. Discharge calculated by applying velocity factor of SIV to the Chiu-2D velocity-flow rate distribution and discharge based on depth of water velocity average conversion factor of 0.85 were $0.7171m^3/sec$ and $0.5758m^3/sec$, respectively. Their error rates compared to average ADCP discharge of $0.6664m^3/sec$ were respectively 7.63% and 13.64%. Discharge based on the Chiu-2D velocity-flow distribution showed lower error rate compared to discharge based on depth of water velocity average conversion factor of 0.85.

• Women's Health Nursing
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• v.2 no.2
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• pp.284-297
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• 1996

A maternity ward in a hospital in Seoul has an educational program for postpartal mothers since its opening, but evaluation on the program has not been done. This study was to find whether the educational program contributed to increase of knowledge and confidence of the post-partal mothers in the area of postpartal self-care and the newborn baby care or not. This study aimed at improvement of the educational program for posrpartal mothers and the newborn babies. Subjects were 40 primiparae who were admitted to the obstetric ward in a general hospitals in Seoul from August 20th to September 10th, 1995. Subjects were those who had no labor pain at the admission time, had no complications during labor and delivery, gave a birth to a healthy baby, and agreed to participate in this study. All subjects were well educated and were in well-to-do group. Most of them received antenatal care adequately. They were tested on knowledge and self-confidence in the area of postpartal self-care and infant care two times, one at the admission time and the other prior to discharge. After the first test, nurses in a maternity ward and nursery taught them on postpartal self-care and infant care. Education consisted of a 1 hour planned program and incident teachings done at bed side. Four tools were developed by authors based literature review. The test tool for knowledge of postpartal self-care consisted of 15 items which included the definition of postpartum, dangerous symptoms in postpartum, lochia, time to begin coitus, postpartum exercise, sitz-bath, and perineal care. The test tool for self-confidence in postpartal self-care included such items as emergency care on dangerous symptoms in postpartum, sexual life and contraception after postpartum, self-confidence in postpartum exercise and perineal care. The test tool for knowledge of newborn baby care consisted of 18 items which included bathing, umbilical cord care, vaccination, breast feeding, abnormal symptoms of neonate. The test tool for self confidence in the newborn baby care included umbilical cord care, vaccination, breast feeding, emergency care for baby. Analysis of demographic data were analyzed with calculation of percentage. Score differences between the first test and the second test were analyzed with paired t-test. SAS / PC (Release 6.04 for DOS) program are as follows. 1. Mothers' knowledge of postpartal self-care increased significantly after education (t=10.04, df=38, p=0.0001). 2. Mothers' self-confidence in postpartal self-care increased significantly after education (t=6.53, df=38, p=0.0001). 3. Mother's knowledge of the newborn abay care increased significantly after education (t=9.74, df=38, p=0.0001). 4. Mothers' self-confidence in the newborn baby care increased significantly after education(t=8.22, df=38, p=0.0001) Suggestions for further studies and nursing practice were as follows. 1. We suggest studies by randomized control-group pretest-posttest design or nonequivalent control group pretest-posttest design will be done. 2. We suggest follow-up studies to find if mothers's confidence will last or not after discharge. 3. We suggest general hospitals to establish a phone-counseling system.

• Journal of Electrochemical Science and Technology
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• v.2 no.2
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• pp.76-84
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• 2011

Potentiostatic oxidation of Pb-1.7%Sb alloy used in the manufacture of grids of lead-acid batteries over the potential range from -1.0V to 2.3V in 5M $H_2SO_4$ in the absence and the presence of 0.4M $H_3PO_4$ and the self-discharge characteristics of the oxide layer formed is studied by electrochemical impedance spectroscopy (EIS). Depending on the potential value, sharp variations in resistance and capacitance of the alloy are recorded during the oxidation and they can be used for identification of the various substances involved in passive layer. Addition of $H_3PO_4$ is found to deteriorate the insulating properties of the passive layer by the retardation of the formation of $PbSO_4$. $H_3PO_4$ completely inhibits the current and impedance fluctuations recorded in $H_3PO_4$-free solutions in the potential range 0.5 V-1.7 V. These fluctuations are attributed to the occurrence of competitive redox processes that involve the formation of $PbSO_4$, $PbOSO_4$, PbO and $PbO_2$ and the repeated formation and breakdown of the passive layer. Self-discharge experiments indicate that the amount of $PbO_2$ formed in the presence of $H_3PO_4$ is lesser than in the $H_3PO_4$-free solutions. The start of transformation of $PbSO_4$ into $PbO_2$ is greatly shortened. $H_3PO_4$ facilitates the diffusion process of soluble species through the passive layer ($PbSO_4$ and basic $PbSO_4$) but impedes the diffusion process through $PbO_2$.

• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.311-319
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• 2018

The purpose of this study was to identify the degree of uncertainty, uncertainty appraisal, and self-efficacy in pre-discharge arthroscopic patients and to investigate the effects of their uncertainty. This study was carried out from April to October 2016 as a descriptive research study. The subjects were presented with pre-discharge convenience sampling after arthroscopic surgery. The data of 131 patients were analyzed by t-test, ANOVA and Scheffe post-test, Pearson correlation coefficient calculation and multiple regression analysis using SPSS 18.0. As the results of this study, education level, presence of spouse, preoperative korean traditional medicine treatment experience and self-efficacy were found to have significant effects on uncertainty. The results of this study suggest that in hospital and pre-discharge education program development to reduce patient uncertainty after arthroscopic surgery.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.2
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• pp.151-158
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• 2019

Objectives of this study were to identify the hotspot for displacement of the on-line water quality sensors, in order to detect illicit discharge of untreated wastewater. A total of twenty-six water quality parameters were measured in sewer networks of the industrial complex located in Daejeon city as a test-bed site of this study. For the water qualities measured on a daily basis by 2-hour interval, the self-organizing maps(SOMs), one of the artificial neural networks(ANNs), were applied to classify the catchments to the clusters in accordance with patterns of water qualities discharged, and to determine the hotspot for priority sensor allocation in the study. The results revealed that the catchments were classified into four clusters in terms of extent of water qualities, in which the grouping were validated by the Euclidean distance and Davies-Bouldin index. Of the on-line sensors, total organic carbon(TOC) sensor, selected to be suitable for organic pollutants monitoring, would be effective to be allocated in D and a part of E catchments. Pb sensor, of heavy metals, would be suitable to be displaced in A and a part of B catchments.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.4
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• pp.8-14
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• 1994

The aim of this paper is the introduction and investigation of the characteristics and outline of self-unloading systems from the bulk handling point of view. Some years of experiences from the building of self-unloading bulk carriers are described hereunder.

• Journal of the Korean Vacuum Society
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• v.13 no.3
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• pp.132-138
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• 2004

We used the self-consistent one-dimensional model applied to FCT algorithm and FEM method in a wire-cylinder type reactor to study the characteristics of corona discharge plasma in air at the atmospheric pressure. At the pulsed do voltage and do voltage, we studied the changes of the characteristic of plasma by computing electron density profile according to the changes of voltage and the size of reactor. The changes of active radius from this result are compared with the data of Peek's. The numerical simulation results for a corona discharge plasma explain the physical mechanism of the discharge process and could be used to obtain the optimized parameters for designing the plasma reactor for pollution abatement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.85-91
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• 2015

A gasoline engine automobile uses high voltage generation of the ignition coil, igniting and burning mixed fuel in the combustion chamber, which drives the engine. When the electronic control unit intermits a current supplied to the power transistor, counter electromotive force with a low voltage is generated by self induction action in the ignition primary coil and a high voltage is induced by mutual induction action with the primary ignition coil in the second ignition coil. The high voltage is supplied to the ignition plug in the combustion chamber, causing a spark, igniting the compressed mixed fuel. If a very small defect occurs inside the insulating material when a voltage is applied in said ignition coil, the performance of the insulation material will get worse and breakdown by a partial discharge of corona discharge. Thus, in this experiment, we are to contribute to improve the performance and ensure the reliability of the ignition coil by investigating partial discharge characteristics according to the change of voltage and temperature when a voltage is applied to the specimen of the epoxy molding ignition coil.

• Child Health Nursing Research
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• v.10 no.4
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• pp.460-467
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• 2004

Purpose: The purpose of this study was to develop a program promoting self-esteem and to determine the effectiveness of the program for hospitalized school-aged children. Method: The sample group consisted of 68 hospitalized children in a University Hospital located in Busan. The experimental group was given the program and feedback was obtained 3 times up until the day of discharge. Data were analyzed using t-test and 2-way ANOVA with the SPSS program package. Result: There was a significant difference between experimental and control groups in self-esteem. Conclusion: It was found that the program promoting self-esteem in school aged children was effective. The program, which was based on learning theory, was shown to be an effective and strong method to promote adjustment in hospitalized school-aged children.