• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.4
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• pp.1-11
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• 2022

In this study, the thermal runaway of NCM and LFP batteries were compared and analyzed through numerical analysis under various conditions. Comparing the thermal runaway of the NCM622 (18650) battery cell and the LFP (18650) battery cell through oven test simulation, the LFP battery did not show thermal runaway, whereas the NCM622 battery temperature increased to 710℃ in 12 minutes. To observe the thermal runaway and propagation of the prismatic LFP battery cell, the internal temperature was set at 200℃ and the oven test simulation was conducted. It was found that thermal runaway occurred at 391℃ after 47 minutes. As a result of observing thermal runaway propagation by placing five NCM622 and LFP battery cells, the thermal runaway propagation was clearly observed in the case of the NCM622 battery, but in the case of the LFP battery, thermal runaway was not observed after the first cell. From the third battery cell, it was confirmed that the temperature change was very insignificant, and through this, it is considered that the LFP battery is relatively safe compared to the NCM battery in terms of the thermal runaway propagation of the battery.

• Journal of the Korean Society of School Health
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• v.36 no.2
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• pp.52-61
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• 2023

Purpose: The purpose of the study was to compare the characteristics between adolescents who have run away from home before and who have contemplated running away from home before, and to find risk factors that predict runaway behavior among them. Methods: The data of 「the survey on adolescents' right to adequate housing and the way to ensure their housing with the focus on social exclusion」 by the National Youth Policy Institute (2020) were analyzed. A total of 494 adolescents were included in the study. Descriptive statistics, x2 test, t-test, and simple and multiple logistic regressions were carried out using SAS 9.2. Results: Gender, depression, anxiety, self-esteem, and school level were significantly different between the two groups. From the multivariate analysis, the adjusted odds ratio for runaway behavior was significantly higher in male students (AOR: 2.14, p<.001), lower in the middle economic class than in the high economic class (AOR: 0.64, p=.051), lower in the 4th quartile group of self-esteem (AOR: 0.52, p=.041), and higher in high school students (AOR: 1.55, p=.050). Conclusion: Considering that male students, students from wealthier families, students with low self-esteem, and high school students are high-risk groups for runaway behavior, among adolescents who have contemplated running away before, interventions targeting these groups are needed.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.194-194
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• 2010

The variable demand on the energy market, as well as the limited energy storage capabilities, requires a great flexibility in operating hydraulic turbines. But, present in Korea, the absence of testing laboratories and technical criteria for the performance test of small hydropower degrades the efficiency of the domestic hydropower machines, A performance guarantees for hydro turbines shall be contain, as a minimum, guarantees covering power, discharge and specific hydraulic energy, efficiency, maximum momentary overspeed and maximum momentary pressure and/or maximum steady-state runaway speed, as well as guarantees related to cavitation. Performance test are conducted by the test standard. Test codes based on extensive research data are written under the leadership of an IEC. Performance evaluation is carry out several test(performance test, cavitation test and runaway test). The paper presents the international turbine test laboratory and performance test standard.

• Child Health Nursing Research
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• v.7 no.4
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• pp.483-493
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• 2001

This study is attempted to define risk factor of youth runaway impulse and to structure forecast model through an extensive analysis of the factors influencing the runaway impulse of youth. The subjects were 610 high school students in Seoul and Kyunggido. The collected data was analysed by SAS. The differences between the runaway impulse group and the non-runaway impulse group were subject to chi-square and t-test. Also logistic regression analysis was conducted on the basis of purposeful selection method for constructing the forecast model. The findings are as follows : the major predicting factors of youth runaway impulse are sex(odds ratio=1.886, p=.009), existence of friends of the opposit sex(odds ratio=2.011, p=.007), anti-social personality(odds ratio= 4.953, p=.000), depressive trend(odds ratio= 2.695, p=.000), family structure(odds ratio= 5.381, p=.000), marital relationship(odds ratio =1.893, p=.009) and also between parents and youth(odds ratio=3.877, p=.000), emotional abuse(odds ratio=1.963, p=.003), authoritative controlled rearing(odds ratio=2.135, p=.005) and stress from school(odds ratio=1.924, p=.008). Therefore, the forecast model will be contribute to the nursing intervention for prevention of runaway youth.

• Research in Community and Public Health Nursing
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• v.18 no.4
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• pp.662-672
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• 2007

Purpose: In recent years, the problem of runaway youths, which is rapidly increasing and worsening in nature, has emerged as a serious problem to individuals, home and the society as a whole. Against this back drop, this study was designed to illuminate the danger signals through extensive analysis of factors influencing the running away of middle-school students and, on this basis, build a forecast model on runaway middle-school students. Method: The subjects of this descriptive survey on the causal relation were 592 subjects enrolled in middle schools selected through convenience sampling. The data collected from June 19 to July 19, 2003 were analysed through the SPSS 10.0 program. The differences between the runaway group and the non-runaway group were determined through chi-square and t-test. Also logistic regression analysis was conducted on the basis of the purposeful selection method for constructing the forecast model. Result: The findings are as follows: Individual-related factors predicting runaway middle-school students were smoking experience, delinquent experience, psychosomatic symptoms and stress. A home-related factor was attachment to family. A society-related factor was the number of delinquency friends. Conclusion: The findings of this study suggest that a broad intervention program should be provided to middle-school students' culture related to runaway group. It is also recommended that a variety of individual, home and society-related programs should be developed for the runaway group.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.120-125
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• 2011

SPDs are increasingly being used against lightning and switching surge according to the applicable revised standard and equipotential grounding system. SPDs are equipped usually with a MOV voltage regulating element. The MOV, however, always is exposed to the danger of thermal runaway resulting from inrushing temporary overvoltage and deterioration. In this paper, the authors made two prototype SPDs built-in Instantaneous trip device and analyzed their limiting voltage through test of the MOV breakdown. As the result of the analysis, the SPDs built-in Instantaneous trip device was proven to be effective for protecting MOV against thermal runaway and Instantaneous trip device react for limiting voltage is considered that is applicable to SPD.

• Journal of the Korean Home Economics Association
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• v.48 no.1
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• pp.111-125
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• 2010

The purpose of this study was to develop and evaluate the efficacy of a Family Relationship Enhancement Program for runaway youth. The theoretical framework of this program was based on Solution-Focused, Satir's Experiential, and Cognitive-Behavioral models. Need assessment analysis of youth shelter workers, focus group interviews with runaway youths, and advisory council meetings were used as a complementary resource for this study. Thirty-one runaway youths from 6 youth shelters in Seoul and Kyunggi participated in 4 two-hour sessions of this Family Relationship Enhancement Program. All participants were subjected to pre-test and post-test analysis in order to assess the efficacy of the program. The results of this study showed that the Family Relationship Enhancement Program had significantly increased the participants' self-esteem, communication capability, and understanding of family values.

• Journal of the Korean Institute of Gas
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• v.18 no.4
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• pp.27-34
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• 2014

In this study, we evaluated an effect of the tempered materials on the thermal runaway characteristics in the resol resin synthesis reaction using the adiabatic calorimetry of vent sizing package 2(VSP2). The kinetic parameters, such as an activation energy and heat of reaction, were estimated using the test results. As the results, the instantaneous characteristics to express the intensity of runaway reaction decreased at the low solid content. However, the sudden loss of the tempered materials triggered the second runaway reaction rapidly. In this condition, the heat of reaction and the activation energy of phenol and p-formaldehyde were about 157 kJ/mol and 60 kJ/mol, respectively.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.27 no.3
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• pp.181-187
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• 2016

Objectives: This study investigated the relationship between depression, attachment and addiction problems in runaway youths. Methods: We sent a questionnaire package to 187 runaway youths in 18 adolescent shelters. The questionnaire package collected their sociodemographic data and included the Patient Health Questionnaire-9, Inventory of Parent Attachment (IPA), Korean Internet Addiction Self-Scale (K-Scale), Korean version of Alcohol Use Disorders Identification Test, and Korean version of the $Fagerstr{\ddot{o}}m$ Test for Nicotine Dependence. Results: The percentage of youth with depression was 28.8% (N=54). In the depression group, there were significantly more problematic alcohol users (53.06%, p=.0199) and significantly lower IPA scores (p=.0064). There was a significant negative correlation between depression and a IPA, and significant positive correlation between depression and the K-Scale. Conclusion: These results suggest that runaway youths with depression have more problematic alcohol drinking and attachment problems.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.324-333
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• 2009

This paper presents a numerical simulation study of the transient behavior of a $2{\times}340MW$ pump-turbine power plant, where the results show an unstable behavior at runaway. First, the modeling of hydraulic components based on equivalent schemes is presented. Then, the 2 pump-turbine test case is presented. The transient behavior of the power plant is simulated for a case of emergency shutdown with servomotor failure on Unit 1. Unstable operation at runaway with a period of 15 seconds is properly simulated using a 1-dimensional approach. The simulation results points out a switch after 200 seconds of the unstable behavior between a period of oscillations initially of 15 seconds to a period of oscillation of 2.16 seconds corresponding to the hydraulic circuit first natural period. The pressure fluctuations related to both the rigid and elastic water column mode are presented for oscillation mode characterization. This phenomenon is described as a switch between a rigid and an elastic water column oscillation mode. The influence of the rotating inertia on the switch phenomenon is investigated through a parametric study.