• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1131-1137
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• 2017

Recently, regulations on fuel efficiency and $CO_2$ emissions have been reinforced in automobile industries. As a result, many companies make an effort to satisfy these regulations by adapting composite materials to the automobile body as well as its components. In particular, the lower control arm in the suspension system is subjected to heavy loads and is designed to be thick to meet operating loads. Therefore, it is essential for the lower control arm to reduce weight and to secure the durability assessment. In this paper, we conducted structural analysis by performing stress and stiffness analysis under given load conditions through finite element analysis, and verified whether it satisfies the load and stiffness conditions. The inertia relief method is adapted to the process of analysis, and the principal stress is used as a criterion for evaluation. Based on these results, the durability assessment is carried out using the stress-life method.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.1
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• pp.16-24
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• 1999

Residual stress is one of the causes which make defects in engineering components and materials. And interest in the measurement of residual stress exists in many industries. There are commonly used methods by which residual stresses are currently measured. But these methods have a little demerits. time consumption and other problems. Therefore we devised a new experimental technique to measure residual stress in materials with a combination of laser speckle pattern interferometry, finite element method and spot heating. The speckle pattern interferometer measures in-plane deformations while the heating provides for very localized stress relief. FEM is used for determining heat temperature and other parameters. The residual stresses are determined by the amount of strain that is measured subsequent to the heating and cool-down of the region being interrogated. A simple model is presented to provide a description of the method. In this paper, the ambiguity problem for the fringe patterns has solved by a phase shifting method.

• Women's Health Nursing
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• v.23 no.1
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• pp.33-41
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• 2017

Purpose: The purpose of this study was to investigate the effect of aroma inhalation therapy on stress, anxiety, depression, and an autonomic nervous system reaction in high-risk hospitalized pregnant women. Methods: A quasiexperimental study used a non-equivalent control group non-synchronized design. Fifty high-risk hospitalized pregnant women were selected as participants on delivery room and maternity ward at university hospital. Twenty-five were selected for the experimental group while 25 were assigned to a control group. Neroli essential oil was used for aroma therapy and was already identified as not being hazard to pregnant women. It provided emotional stability from previous study. The participants inhaled Neroli 2 minutes, 3 times (9 am to 10 am, 4 pm to 5 pm, just before sleep) a day. A total of 15 sessions were held from the day of the preliminary investigation. Pre and post written survey and measuring an autonomic nervous system reaction were collected from both groups. Results: The data were analyzed by $x^2$ test, t-test, and paired t-test. There was a statistically significant difference in stress (t=-3.98, p<.001) between the experimental group and the control group. Conclusion: These findings indicate that aroma inhalation therapy is effective as a nursing intervention for the stress relief of hospitalized high-risk pregnant women.

• Journal of Digital Convergence
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• v.19 no.9
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• pp.349-360
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• 2021

The purpose of this study is to verify whether social support for single parents in leisure, culture, and info-communication areas has the moderating effect on the impact of stress situations on academic continuity in single parents. To this end, technical statistics and logistic analysis were conducted on 248 single parents who were pregnant or pregnant at the age of 18 or older and raised their children after childbirth. As a result, one out of every four beneficiaries were involved, increasing the possibility of academic continuation by adjusting the stress-induced tendency of single parents to stop studying due to leisure, culture, and information and communication expenses. These results show that leisure, culture, and information and communication support are effectively contributing to improving the academic sustainability of single parents who want to stop studying due to stress relief and stress. Therefore, it is necessary to strengthen leisure, culture, and social support in the information and communication sectors for the academic continuation of single parents of teenagers.

• Animal Bioscience
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• v.34 no.5
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• pp.844-854
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• 2021

Objective: The potential of extra virgin olive oil (EVOO), betaine (BET), and ginger (GIN), as natural antioxidants, in reducing negative effects of heat stress on physiological responses, antioxidant capacity, semen quality and fertility of bucks under heat stress were investigated. Methods: Forty adult Animal Production Research Institute line rabbit bucks were distributed randomly into four experimental treatments of ten rabbits each. The first treatment was fed the commercial pellet diet (CPD) without supplementation and served as a control. The other three treatments were fed CPD supplemented with EVOO (300 mg), BET (1,000 mg), and GIN (200 mg) per kg diet for 3 consecutive months during the summer season. Results: Supplementation of EVOO, BET, or GIN improved (p<0.05) the sexual desire, progressive motility, vitality, intact acrosome and membrane integrity, sperm cell concentration, sperm outputs and fertility. Seminal plasma total proteins, globulin, total antioxidant capacity, glutathione and glutathione S-transferase, and initial fructose increased (p<0.05), while total lipids, aspartate and alanine aminotransferases and malondialdehyde decreased (p<0.05) compared with the control. In comparing the natural antioxidants treatments, GIN evoked the largest improvement. Conclusion: The inclusion of GIN (200 mg/kg diet) appeared to improve the sexual desire, semen quality and oxidative stress of bucks. This may be a beneficial supplement for the management of rabbit bucks used in natural mating or artificial insemination.

• Journal of Animal Science and Technology
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• v.62 no.6
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• pp.875-883
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• 2020

This study was conducted to investigate the effects of group-housing facility (GHF), compared to an individual confinement stall (CON), on the reproductive performance, behavior, and stress hormones of gestating sows. A total of 50 primiparous sows (Landrace × Yorkshire) were randomly allocated into either CON (n = 25) or GHF (n = 25) during the gestation period. One week before parturition, the sows were transferred into conventional farrowing crates, and cross-fostering was conducted within 1 d of delivery. Blood was collected for analyses of stress indices at 75 d of gestation and postpartum. Reproductive performance was estimated during the period of birth to weaning. Behavior patterns were identified at 90 d of gestation. Litter size was not different between the CON and GHF treatments. Weaning to estrus interval, however, tended to be lower in the GHF than in the CON (p < 0.1). Activity, treating, belly nosing, and exploring behaviors were observed only in the GHF group, whereas rubbing was shown only with the CON. Serum cortisol concentration was lower in the GHF than in the CON at 75 d of gestation (p < 0.05). Sows housed in the GHF showed lower epinephrine and norepinephrine concentrations than those housed in the CON at postpartum (p < 0.05). The GHF sows demonstrated more natural behavior characteristics associated with stress relief than the CON sows with no adverse effects on reproductive performance. Therefore, these results suggest that GHF could be applied as an alternative housing facility to improve animal welfare on swine farms.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.369-379
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• 2021

This study was a descriptive survey study to compare the stress, depression, fatigue, and sleep quality between pregnant women with gestational diabetes mellitus (GDM) and normal pregnant women. The study subjects were 49 gestational diabetes mellitus women and 51 normal pregnant women who were matching with gestational diabetes mellitus women by age, gestational age and number of births. The data collection was measured using structured questionnaires, numerical scales, and Canopy9 RSA(IEMBIO, Gangwondo, Korea) equipment. As a result of the study, pregnant women with gestational diabetes had higher pre-pregnancy weight(t=3.698, p<.001) and higher stress(t=4.505, p<.001), depression(t=4.564, p<.001), and fatigue(t=3.709, p<.001) during pregnancy, so weight management is important before pregnancy, and stress, fatigue, and depression relief nursing

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3A
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• pp.227-234
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• 2009

Recently, a knee brace is usually installed in connection between cross-beam and main-girder of steel box-girder bridges. The knee brace is installed as a structural stiffener and mainly aims to relieve stress at joints and to prevent main-girder from lateral deformation. However, research on the knee brace is insufficient to obviously evaluate the necessity. The stiffened effect of knee brace is determined by using finite element analyses. Stress distribution, stress level of members and deflection of the cross-beam are evaluated by parametric FE analysis for the installation of knee brace and the depth ratio of cross-beam/steel box girder. It is seen from comparison of numerical analysis results that the knee brace installed in cross-beam of steel boxgirders bridges is not efficient as a structural stiffener with respect to stress relief and stiffened effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.352-362
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• 2016

The purpose of this study was to examine the level of stress, healthcare accreditation related job stress, adaptation, and turnover intentions, as well as to identify influencing factors of turnover intentions for operating room nurses. This study employed a descriptive correlational design. The data were collected from 163 operating room nurses using a structural questionnaire. Stress was different by age (F=5.629, p=.004), marital status (t=-2.907, p=.004), and children (t=-2.623, p=.010). Healthcare accreditation related job stress was different by age (F=11.924, p<.001), marital status (t=-4.747, p<.001), children (t=-4.434, p<.001), work experience in the OR (F=6.000, p=.003), and work reasons in the OR (t=-2.543, p=.012). Turnover intention was different by age (F=21.472, p<.001), education level (F=4.997, p<.008), religion (t=3.235, p=.001), work experience in the OR (F=13.599, p<.001), position (t=3.222, p=.002), work reasons in the OR (t=-3.001, p=.003), and a shift pattern of duties (t=-2.797, p=.006). Turnover intention was significantly correlated with stress, healthcare accreditation related job stress, and adaptation. Factors affecting turnover intention were healthcare accreditation related job stress, adaptation, and age. These factors accounted for 36.2% of turnover intention. These results suggest that relief of stress and healthcare accreditation related job stress and interventions for improving stress management.

• Geomechanics and Engineering
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• v.14 no.5
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• pp.439-451
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• 2018

The stress path characteristics of surrounding rock in the formation of gob were analysed and the unloading was solved. Taking Chengchao Iron Mine as the engineering background, the model for analysing the instability of deep gob was established based on the mechanism of stress relief in deep mining. The energy evolution law was investigated by introducing the local energy release rate index (LERR), and the energy criterion of instability of surrounding rock was established based on the cusp catastrophe theory. The results showed that the evolution equation of the local energy release energy of the surrounding rock was quartic function with one unknown and the release rate increased gradually during the mining. The calculation results showed that the gob was stable. The LERR per unit volume of the bottom structure was relatively smaller, which mean the stability was better. The LERR distribution showed that there was main energy release in the horizontal direction and energy concentration in the vertical direction which meet the characteristics of deep mining. In summary, this model could effectively calculate the stability of surrounding rock in the formation of gob. The LERR could reflect the dynamic process of energy release, transfer and dissipation which provided an important reference for the study of the stability of deep mined out area.