• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.6
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• pp.253-266
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• 2020

The extended slip-weakening model was investigated by using a compiled set of source-spectrum-related parameters, i.e. seismic moment M_o, S-wave velocity V_s, corner-frequency f_c, and source-controlled high-cut frequency fmax, for 113 shallow crustal earthquakes (focal depth less than 25 km, M_W 3.0~7.5) that occurred in Japan from 1987 to 2016. The investigation was focused on the characteristics of stress drop, radiation energy-to-seismic moment ratio, radiation efficiency, and fracture energy release rate, G_c. The scaling relationships of those source parameters were also investigated and compared with those in previous studies, which were based on generally used singular models with the dimensionless numbers corresponding to f_c given by Brune and Madariaga. The results showed that the stress drop from the singular model with Madariaga's dimensionless number was equivalent to the breakdown stress drop, as well as Brune's effective stress, rather than to static stress drop as has been usually assumed. The scale dependence of stress drop showed a different tendency in accordance with the size category of the earthquakes, which may be divided into small-moderate earthquakes and moderate-large earthquakes by comparing to M_o = 10¹⁷~10¹⁸ Nm. The scale dependence was quite similar to that shown by Kanamori and Rivera. The scale dependence was not because of a poor dynamic range of recorded signals or missing data as asserted by Ide and Beroza, but rather it was because of the scale dependent V_r-induced local similarity of spectrum as shown in a previous study by the authors. The energy release rate G_c with respect to breakdown distance D_c from the extended slip-weakening model coincided with that given by Ellsworth and Beroza in a study on the rupture nucleation phase; and the empirical relationship given by Abercrombie and Rice can represent the results from the extended slip-weakening model, the results from laboratory stick-slip experiments by Ohnaka, and the results given by Ellsworth and Beroza simultaneously. Also the energy flux into the breakdown zone was well correlated with the breakdown stress drop, ${\tilde{e}}$ and peak slip velocity of the fault faces. Consequently, the investigation results indicate the appropriateness of the extended slip-weakening model.

• Child Health Nursing Research
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• v.19 no.1
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• pp.39-48
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• 2013

Purpose: The purposes of this study were to assess the parenting stress in mothers of premature infants and stress related characteristics of mothers and infants. Methods: The methodology was a cross sectional survey study using self-report questionnaires. Participants in this study were 36 mothers of infants with corrected ages of 4 months to 12 months who were born prematurely. Data were analyzed using t-test, ANOVA, and Pearson correlation with the SPSS WIN 19.0 program. Results: The mean score for parenting stress in mothers of premature infants was $74.639{\pm}17.570$, indicating that the mothers actually experienced stress. When mothers were able to have some private time, parenting stress was statistically significantly lower. When the residential status was having one's own house and the local community provided informational support regarding child nurturing, there was a statistically significant decrease in the sub-category of particular infant temperament. There was a statistically significant positive correlation between mothers' depression and parenting stress. Conclusion: These results indicate that there is a need for nursing interventions to increase mothers' private time and to include informational support regarding health management of children including developmental status assessment from local communities.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.23-30
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• 2019

The purpose of this study was to examine job stress, job satisfaction, and turnover intention of the nurses who work at the comprehensive nursing service units in two academic medical institutions that provide healthcare service at the tertiary care level in Korea. A descriptive study was conducted with the nurses by using self-reported questionnaires. We used descriptive statistics to summarize the data and Mann-Whitney U test for group comparison. The mean scores of job stress, job satisfaction, and turnover intention were $89.17{\pm}12.56$, $107.25{\pm}6.85$, $37.19{\pm}4.86$, respectively. Nurses with religion showed more job stress than those without. Nurses with their age below 30 years old had significantly less job satisfaction than those older than 30 years old. Monthly income was significantly associated with turnover intention in our data. The top three sub-category of the job stress were conflict with physicians, patients and their caregivers, and conflicts with others; and those of the job satisfaction were pay and promotion and task requirement. Job stress, job satisfaction, and turnover intention were significantly correlated. In order to reduce turnover intention of nursing professionals in the comprehensive nursing service, job stress related to issues on relationships with patients, their family, health care providers need to be taken into consideration. Policy and administrative support are needed to improve their work environment.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.11
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• pp.1036-1042
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• 2011

APR1400 RVI CVAP using the non-prototype category II is being conducted to verify integrity of the RVI design and to secure the CVAP technology. The measurement programs are to confirm vibration analysis results for reactor internals during pre-operational and initial startup testing and to determine the safety margin. One of the important basis for the measurement programs is test acceptance criteria. Therefore, this paper is on establishment of response instrumentation test acceptance criteria for APR1400 RVI CVAP. The established acceptance criteria show that the stress criteria of APR1400 RVI are more conservative values than those of the valid prototype plant(Palo Verde unit 1) and, the displacement criteria of the inner barrel assembly and the upper guide structure were established to 0.03 in and 0.01 in, respectively.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.12
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• pp.655-660
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• 2003

This paper proposes new single stage power factor correction (PFC) full bridge converter. The proposed converter is combined previous ZVS full bridge DC/DC converter with two inductors, two diodes, two magnetic coupling transformer for PFC. This process of power is isolated from the source and also regulate stable DC output voltage in a category. In this topology, the voltage stress of main switches is reduced by zero voltage switching. Moreover, the proposed converter doesn't need active PFC switch and auxiliarly circuits, like control and gating board, so it could decrease the size and cost and increase the efficiency.

• Journal of Korean Academy of Nursing
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• v.31 no.6
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• pp.988-997
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• 2001

This study aimed at uncovering the experience of adaptation of the new nursing staff in hospital setting. Methods: For this study, 15 new graduate nurses participated. The data was collected through the in-dept interviews and analysed in terms of Strauss and Corbin′s grounded theory methodology. Results: The core category was identified with "entering orbit". The new graduate nurses, who experienced the taeoom because of their unskilled professions, tried to enter orbit by overcoming difficult situations through reducing stress, maintaining good interpersonal relationship, grasping, compensating, persisting, and introspecting. Noticeably, in the process of adaptation, negative image of nursing, conflict of interpersonal relationship and the educational program for the new nursing staff had effect on the intervening factors. Finally, this study confirmed that the processes of new nurses′ adaptation are confusing, confrontating, becoming a member and settling in hospital setting. Conclusion: Therefore, the educational programs reflecting new nursing staffs′ experiences should be developed.

• Journal of Korean Public Health Nursing
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• v.28 no.2
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• pp.359-371
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• 2014

Purpose: This study was conducted in order to describe the process of appearance management with esthetic treatment and for development of a substantive theory that explains lifestyle in female college students. Methods: The participants were seven students who had undergone a surgical procedure with LASEK, cosmetic, and wearing orthodontic brackets. Data were collected through face-to-face interviews and analyzed using grounded theory in Strauss and Corbin (1998). Results: The core category, 'discovering factors of social opportunities' incorporated the relationship between and among all categories and explained the process. Theses processes were categorized acording to four stages: 'facing appearance stress', 'screening medical information', 'applying esthetic treatment', and 'restoring self-confidence'. Conclusion: The findings of this study indicate an understanding and profound insight on the issue of psycho-social health promotion in young female.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1455-1464
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• 1994

A new and efficient algorithm for the integration of the thermal-elasto-plastic constitutive equation is proposed. While it falls into the category of the return mapping method, the algorithm adopts the three point approximation of plastic corrector within one time increment step. The results of its application to a von Mises-type thermal-elasto-plastic model with combined hardening and temperature-dependent material properties show that the accurate iso-error maps are obtained for both angular and radial errors. The accuracy achieved is because the predicted stress increment in a single step calculation follows the exact value closely not only at the end of the step but also through the whole path. Also, the comparison of the computational time for the new and other algorithms shows that the new one is very efficient.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1239-1243
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• 2009

To evaluate the structural integrity of the nuclear seismic category penetration cooling water pump under the seismic service conditions the seismic analysis was performed in accordance with IEEE-STD-344 code. The finite element computer program, ANSYS, Version 10.0, is used to perform both a mode frequency analysis and an equivalent static seismic analysis of the pump assembly. The mode frequency analysis results show the fundamental natural frequency is greater than 33 Hz and does not exist in seismic range, thus justifying the use of the static analysis. The stresses resulted from various loadings and their combinations are within the allowable limits specified in the above mentioned IEEE code. The results of the seismic evaluation fully satisfied the structural acceptance criteria of the IEEE code. Accordingly the structural integrity on the pump assembly was proved.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.212-218
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• 2011

APR1400 RVI CVAP using the non-prototype category is being conducted to verify integrity of the RVI design and to secure the CVAP technology. The measurement programs are to confirm vibration analysis results for reactor internals during preoperational and initial startup testing and to detemine the safety margin. One of the important basis for the measurement programs is test acceptance criteria. Therefore, this paper is on establishment of response instrumentation test acceptance criteria for APR1400 RVI CVAP. The established acceptance criteria show that the stress criteria of APR1400 RVI are more conservative values than those of the valid prototype plant(Palo Verde unit 1) and, the displacement criteria of the IBA and the UGS were established to 0.03 in and 0.01 in, respectively.