• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.11
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• pp.784-791
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• 2012

The casing has been used as a protective conduit during all phases of drilling operations and productions for the oil and gas industries. The casing is manufactured in various diameters, wall thicknesses, lengths, strengths, and connections. When the casing is designed, it has to be considered to withstand a variety of forces, such as collapse, burst, and tensile failure, as well as chemically aggressive brines. Once the casing is damaged, serious problems in geothermal well have been detected continuously. Therefore, this paper describes the casing design for stability of geothermal well to determine influence of casing parameters on the strength and load. In addition, the casing design program was developed. The estimated collapse, burst, tension and depth pressure can provide benefit in the casing design and completion method. This program provides a safety factor and predicts the casing stress more easily.

• Journal of the Korea Society of Computer and Information
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• v.21 no.8
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• pp.85-94
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• 2016

The purpose of this research is to clarify the effect that group art therapy with ceramics affects aggression and impulse for juvenile delinquent. The experimental domain of this study was implemented with 24 juvenile delinquent suspended from protective dispositions for them who were in long-term juvenile sheltered housing about for 12 years. These subjects were selected from among juvenile delinquent between 14 to 20 years age who were entrusted from court to the Juvenile Protection Education Institute located in G area. 12 people were randomly assigned each experimental domain and control domain; experimental group was implemented group art therapy with ceramics whereas there was anything to control group. The program was designed once a week and 90minutes each 12 sessions. The result of this study show that control group at variable related aggression was not significantly changed at posttest. In case of experimental group, here was significantly changed as a whole, also sub factor such as physical aggression showed considerable change so that the first hypothesis was supported In addition, experimental group showed the considerable change at sub factor of motor impulsiveness so that the second hypothesis was supported whereas control group at impulse variable was not significantly changed during pretest and posttest. This study results conclude that the juvenile delinquent participating group art therapy with ceramics represents the effect on reduction of aggression and motor impulsiveness. We expect this result will be used as further base line data for juvenile delinquent.

• The Journal of Korean Medicine
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• v.23 no.1
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• pp.50-60
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• 2002

Objectives: Sunghyangjunggisan (SHJS) is a commonly prescribed drug with a wide neuropharmacological spectrum. The water extracts of SHJS were found to be protective against neurotoxicity elicited by deprivation of serum and glucose. Methods: The morphological examination and Hoechst staining of nucleus also clearly showed that the extracts attenuated the cell shrinkage, membrane blebbing, representing typical neuronal apoptotic phenomena and nucleosome-sized fragmentation under the microscope in PC 12 rat pheochromocytoma cells. Results: Activation of protein kinase A (PKA) with dibutyl-cAMP and forskolin also protected during glucose deprivation, although it was not additive with the effect provided by phorbol ester. Interestingly, treatment with the protein kinase A inhibitor, KT5720, was not neuroprotective in the presence of SHJS. Electrophoretic mobility shift assays were used to characterize the neuroprotective binding of nuclear proteins to consensus sequences for AP-l, nuclear factor kappa B ($NF-{\kappa}B$) after glucose deprivation. When PC 12 cells are induced to undergo apoptosis by serum deprivation, AP-l and $NF-{\kappa}B$ DNA binding activity transiently increases to a slight degree. This stimulation is blocked by the water extracts of SHJS. The site of action of the drugs appeared to involve specific inhibition of AP-1 and nuclear factor kB binding activity. Conclusions: Taken together, these results suggested the possibility that the extracts of SHJS might provide a neurotrophic-like activity in PC 12 cells.

• Research in Community and Public Health Nursing
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• v.26 no.1
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• pp.42-51
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• 2015

Purpose: The aim of this study is to determine the impact of abuse experience and coping styles on suicidal ideation in Korean elders. Methods: Data were collected from the 2011 Korean National Survey on the Elderly. The participants were 10,537 elders aged 65 or older who had replied to the question on suicidal ideation. Socio-demographic and health related factors, abuse experience, and coping style were included as the influence factors of suicidal ideation. Data were analyzed using ${\chi}^2$-test and logistic stepwise regression with the SPSS/WIN 21.0 program. Results: The prevalence of abuse experience among the elders was 12.7% and that of suicidal ideation was 11.2%. Elders with abuse experience (OR=2.79, 95% CI=2.39~3.26) were more likely to have suicidal ideation but those with an active coping style (OR=0.69, 95% CI=0.57~0.84) were less likely to have suicidal ideation even with other influence factors controlled. Conclusion: Abuse experience of the elderly was a major risk factor that increased suicidal ideation, and active coping style was a protective factor that reduced suicidal ideation. These findings show that careful attention to elderly abuse and education for active coping style are necessary to reduce suicidal ideation among the elderly.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1953-1958
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• 2012

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with such electric faults, specially short circuit faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30ms(KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problem, this paper proposes a prevention apparatus using the line voltage drop of neutral wire and some semiconductor switching devices. Some experimental tests of the proposed apparatus confirm the validity of the analytical results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1925-1929
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• 2007

This paper is studied on a novel Electric Safety Protection Device (ESPD) of high speed for incapable operation of Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB) using the low voltage distribution line. The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device (RCD), that is ELB and MCCB, of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this research development is proposed to a novel ESPD of high speed to trip of distribution line on electric arc or spark due to electrical fire. Some experimental results of the proposed ESPD are confirmed to the validity of the analytical results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.876-880
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• 2013

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The principal factor of the fire is electric arc or spark accompanied with such electric faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problems, this paper studies on an arc fault circuit interrupter (AFCI) using the distorted voltage wave in electric arc faults. The proposed voltage sensing type AFCI is an electrical fire prevention apparatus of new conception that operates a circuit breaker with sensing the instantaneous voltage drop of line voltage at electrical faults occurrence. The proposed AFCI is composed of control circuit topology using some semiconductor switching devices. Some experimental tests of the proposed AFCI confirm practicality and the validity of the analytical results.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.89-96
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• 2018

When a fault occurs in a power system, the existing analytic models for the power system fault diagnosis could generate multiple solutions under the condition of one or more protective relays (PRs) and/or circuit breakers (CBs) malfunctioning, and/or an alarm or alarms of these PRs and/or CBs failing. Therefore, this paper presents an improved analytic model addressing the above problem. It takes into account the interaction between the uncertainty involved with PR operation and CB tripping and the uncertainty of the alarm reception, which makes the analytic model more reasonable. In addition, the existing analytic models apply the penalty function method to deal with constraints, which is influenced by the artificial setting of the penalty factor. In order to avoid the penalty factor's effects, this paper transforms constraints into an objective function, and then puts forward an improved immune clonal multi-objective optimization algorithm to solve the optimal solution. Finally, the cases of the power system fault diagnosis are served for demonstrating the feasibility and efficiency of the proposed model and method.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.487-492
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• 2011

In our previous study, we investigated Chenopodium album Linne (CAL) ethanol extract and its fractions on anti-gastritic actions using the HCl/ethanol and indomethacin induced gastric lesion model and Helicobacter pylori (H. pylori). Based on the results, butanol fraction was most effective among fractions obtained from CAL. This study aims to elucidate the mechanisms of butanol fraction, and betaine as a constituent of the butanol fraction, on gastritis and anti-gastric cancer cell growth. First, we examined antioxidant properties using hydrogen peroxide and superoxide radical, and we found that butanol fraction and betaine may be good antioxidants. Second, cytotoxicity was assessed by measuring cell viability and 4,6-diamidino-2-phenylinodole dihydrochloride (DAPI) staining of human gastric cancer cells (AGS cells). We also examined the relationship between the cytotoxicity and intracellular $Ca^{2+}$ signaling mechanism. The butanol fraction demonstrated cell viability 71.49% at the concentration of 100 ${\mu}g/ml$ and increased intracellular $Ca^{2+}$ concentration in a dose dependent manner. Finally, we observed the mucus content as a defensive factor and gastric secretion as an aggressive factor, and found that the mucus content noticeably increased when treated with butanol fraction and betaine and gastric secretion decreased when treated with betaine in vivo study. From these results, we suggest that CAL butanol fraction and betaine may have protective effects on gastritis.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.293-299
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• 2019

This study aimed to analyze the relationship between interpersonal problem, stress coping strategies and mental health for university students at risk of smartphone addiction using a structural equation modeling. Key results of the analysis were as follows. The interpersonal problem increased the severity of mental health. Stress coping strategies had partial mediating effects in the relationship between interpersonal problem and mental health. Passive coping strategy was risk factor and Active coping strategy was protective factor. Based on these results, various interventions for improving mental health for university students at risk of smartphone addiction were suggested.