• Journal of Families and Better Life
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• v.30 no.5
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• pp.75-88
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• 2012

The purpose of this study was to investigate the influences of variables related to family and employment on work family spillover in working wives with children. Korean Longitudinal Survey of Women & Families(KLoWF; 2008) of Korea Women's Development Institute was used in this study. The subjects of this study were 733 working wives with children. For data analysis Cronbach ${\alpha}$, and multiple regression were performed. The results show that, first, among variables related to family, family role awareness and marital satisfaction influence on work-family negative spillover, and values on familism and husband's weekends housework hour influence on family-work negative spillover in working wives with children. Second, among variables related to employment, career satisfaction, wife's weekly working hour, husband's perception on employment of wife and sexual discrimination influence on work-family negative spillover, and career satisfaction, husband's perception on employment of wife, employment stability, husband's monthly income and husband's weekly working hour influence on family-work negative spillover in working wives with children. Third, among variables related to family and employment, wife's weekly working hour, family role awareness, marital satisfaction husband's perception on employment of wive, husband's weekly working hour, and career satisfaction influence on work-family negative spillover, and values on familism and wife's weekly working hour influence on family-work negative spillover in working wives with children.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.19 no.1
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• pp.12-16
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• 1983

The author carried out an experiment to find out the response of cat shark, Scyliorhinus torazame(Tanaka) to the colored lights. The experimental thank (360L$\times$50W$\times$55H cm) was set up in a dark room. Six longitudinal sections with 60cm intervals are marked in the tank to observe th location of the fish. Water depth in the tank was kept 50cm level. Light bulbs of 20W at the both ends of the tank projected the light horizontally into the tank. Two different colored filters were selected from four colors of red, blue, yellow, and white, and they were placed in front of the light bulbs to make different colors of light. Light intensity were controlled by use of auxiliary filters intercepted between the bulb and the filter. The fishes were acclimatized in the dark for 50 minutes before they were employed in the experiment. Upon turning on the light, the number of fish in each section was counted 40 times in 30 second intervals, and the mean of the number of fish in each section was given as the gathering rate of the fish. The favorite color of the fish was found in the order of yellow, white, blue and red in day time, and red, blue, white and yellow at night time. The variation of the gathering rate on illumination time was very little and showed more stability in day time than at night time. The differences of the gathering rates to two selected colors out of the four colors were greater regardless of illumination time.

• Research in Community and Public Health Nursing
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• v.30 no.3
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• pp.357-367
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• 2019

Purpose: The aim of this study is to identify factors of Korean female workers' childbirth plans and to establish measures to improve the childbirth plan. Methods: Study subjects were selected part in the 1st, 3rd, and 5th year surveys of the Korean Longitudinal Panel Survey of Women and Families. The selection criteria were as follows: women who had a spouse; were salaried workers currently employed for the last one month; belonged to a childbearing age; and had less than 3 children. Logistic regression analysis was conducted to investigate factors associated with childbirth plans. Results: Childbirth plans by female workers decreased each year. The analysis of associated factors revealed that age, number of children were associated factors in all years. In addition, education, satisfaction about dividing household chores with the husband, and satisfaction about working environment were associated with the lack of planning for childbirth in female workers in the 1st survey year. Satisfaction about dividing household chores with the husband, family-work conflict, and satisfaction about the potential for personal development were associated factors in the 3rd survey year. Finally, family-work conflict, satisfaction about employment stability, and satisfaction about job task at work were associated factors in the 5th survey year. Conclusion: It is important to know the measures focusing on the lack of planning for childbirth, and hence these factors can be improved by assessing in general, family, and occupational characteristics. Additionally, employer policies regarding women employees who are pregnant or have children at home need to be reviewed.

• Journal of Periodontal and Implant Science
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• v.52 no.2
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• pp.91-115
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• 2022

Purpose: This systematic review aimed to compare the efficacy, defined in terms of the mean percentage of root coverage (mRC), of surgical treatment approaches combined with adhesive restorations of non-carious cervical lesions (NCCLs) to that of root coverage alone in patients with a single gingival recession (GR) and NCCL. Methods: A literature search was conducted to identify longitudinal studies reporting the mRC following treatment for the correction of GR defects associated with NCCLs using a combination of surgical and restorative techniques in systemically and periodontally healthy patients. Results: The search resulted in the retrieval of 12,409 records. Seven publications met the inclusion criteria for the qualitative synthesis of data. The mRCs ranged from 69% to 97%. In the medium term, the gingival margin position was more stable when a connective tissue graft (CTG) was used, independently of whether restoration of teeth with NCCLs was performed. Conclusions: The strength of the evidence was limited by methodological heterogeneity in terms of study design as well as the unit and period of analysis, which precluded a metaanalysis. Although no definitive conclusion could be drawn due to the lack of sufficient evidence to estimate the effectiveness of the interventions, CTG-based procedures contributed to gingival margin stability regardless of the performance of restoration to treat NCCLs.

• Land and Housing Review
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• v.14 no.2
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• pp.1-17
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• 2023

In Korea, the population size of the elderly is rapidly increasing, and housing for them is emerging as an important issue. In particular, Aging in Place (AIP) has steadily been presented as a direction of welfare for the elderly. This study empirically examines the effect of the interactions of the elderly with their children on residential mobility for older Koreans. To do so, this study employed random effect logistic regression models with the dataset of the 2008-2020 Korean Longitudinal Study of Aging. The findings are as follows. First, it was found that the interaction with their children increased the probability of residential mobility for older Koreans in both metropolitan areas and non-metropolitan areas. Second, as age increased, the interaction with their children tended to further promote residential mobility for older Koreans, but such effects varied depending on related variables. Third, it was confirmed that the possibility of further promoting residential mobility for older Koreans increased through the interaction effects of the variables associated with the interaction with their children. This study suggests policy implications for the residential mobility of older Koreans, i.e., whether the interactions with their children improve independent residential environments by enhancing housing stability, in terms of AIP.

• Structural Engineering and Mechanics
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• v.90 no.1
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• pp.83-96
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• 2024

This paper suggests an analytical approach to investigate the free vibration and stability of functionally graded (FG) beams with both perfect and imperfect characteristics using a quasi-3D higher-order shear deformation theory (HSDT) with stretching effect. The study specifically focuses on FG beams resting on variable elastic foundations. In contrast to other shear deformation theories, this particular theory employs only four unknown functions instead of five. Moreover, this theory satisfies the boundary conditions of zero tension on the beam surfaces and facilitates hyperbolic distributions of transverse shear stresses without the necessity of shear correction factors. The elastic medium in consideration assumes the presence of two parameters, specifically Winkler-Pasternak foundations. The Winkler parameter exhibits variable variations in the longitudinal direction, including linear, parabolic, sinusoidal, cosine, exponential, and uniform, while the Pasternak parameter remains constant. The effective material characteristics of the functionally graded (FG) beam are assumed to follow a straightforward power-law distribution along the thickness direction. Additionally, the investigation of porosity includes the consideration of four different types of porosity distribution patterns, allowing for a comprehensive examination of its influence on the behavior of the beam. Using the virtual work principle, equations of motion are derived and solved analytically using Navier's method for simply supported FG beams. The accuracy is verified through comparisons with literature results. Parametric studies explore the impact of different parameters on free vibration and buckling behavior, demonstrating the theory's correctness and simplicity.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.503-515
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• 2017

Underground structures that have recently become larger are required to be stable not only during normal times but also during earthquakes. Especially, it is very important to maintain the stability of the subsea tunnels during the earthquake. The objective of this paper is to verify the effectiveness of the flexible segment, which is one of the breakthrough facilities to maintain the stability of the subsea tunnel during the earthquake using the shaking table test. Another goal of this paper is to propose the optimum position of the flexible segment through 3D dynamic numerical analysis based on the verified results from shaking table tests. The 1g shaking table test considering the similarity ratio (1:100) to the cross section of the selected artificial subsea tunnel was carried out considering the Geongju and Artificial seismic waves, longitudinal and lateral wave, and with/without flexible segments eight times or more. As a result of the shaking table test, it was confirmed that the flexible segment is effective in improving the seismic performance of the undersea tunnel in all the experimental results. In addition, 3D dynamic numerical analysis was performed to select the optimum position of the flexible segment which is effective for improving seismic performance. As a result, it was confirmed that the seismic acceleration is attenuated when the flexible segment is installed adjacent to the branch section in subsea tunnel.

• Journal of Software Assessment and Valuation
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• v.16 no.1
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• pp.55-63
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• 2020

Lasers for optical broadband communication systems should have excellent frequency selectivity and modal stability. DFB lasers have low lasing frequency shift during high speed current modulation. In this paper, when a refractive index grating and a gain grating are simultaneously present in a DFB laser having a wavelength of 1.55 ㎛, the dielectric film is coated so that reflection does not occur on the right mirror surface, so that ρ_r=0. For the first mode, which requires a minimum gain at the threshold, the beam distribution of the oscillation mode in the longitudinal direction and the radiated power ratio P_l/P_r were analyzed and compared for the cases of the phase of ρ_l=π and π/2. If the phase of ρ_l=π, in order to obtain a low threshold current and high frequency stability, κL should be greater than 8. In the case of the phase of ρ_l=π/2, for low threshold current, κL is necessary to be 1.0, where the oscillation frequency coincides with the lattice frequency. DFB lasers with an anti-reflection coated mirror have excellent mode selectivity than 1.55um DFB lasers with two mirror facets

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.855-867
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• 2018

When a weak zone exists ahead of tunnel face, the stress in the adjacent area would increase due to the longitudinal arching effect and the stability of the tunnel is affected. Therefore, it is critical to prepare a countermeasure through the investigation of the frontal weakness zone of the excavated face. Although there are several researches to predict the existence of weak zone ahead of tunnel face, such as geophysical exploration, numerical analysis and tunnel support, lack of studies on the relaxation zone depending on the width or distance from the vulnerable area. In this study, the impact of the weak zone on the formation of the relaxation zone was investigated. For this purpose, a series of laboratory test were carried out varying the width of the weak zone and the separation distance between tunnel face and weak zone. In the model test, sand with a water content of 3.8% was used to form a model ground. The model weak zone was constructed with dry sand curtains. The tunnel face was adjusted to allow a sequential excavation of upper and lower half part. load cells were installed on the bottom of the foundation and the tunnel face and measuring instruments for displacement were installed on the surface of the model ground to measure the vertical stress and surface displacements due to tunnel excavation respectively. The test results show that the width of weak zone did not affect the ground settlement while the ground subsidence drastically increased within 0.25D. The vertical stress and horizontal stress increased from 0.5D or less. In addition, the longitudinal arching effect is likely within the 1.0D zone ahead of the tunnel face, which may reduce the vertical stress in the ground following tunneling direction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.340-348
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• 2020

The purpose of this study was to investigate the mutual relationship between parenting stress and children's problem behaviors among those participating in dream start services. In order to verify the effect of parental and child effects on child's problem behavior and parenting stress based on repeated measures from the first grade of elementary school to the third grade of elementary school among children participating in dream start services, autoregressive cross-lagged modeling was applied. As a result, the stability coefficient showed that the two variables were significantly stable for 3 years. In other words, the measurement was maintained at a similar level with time. The causal relationship between parents 'parenting stress and child' s problem behavior was generally explained by the parental effect. In other words, parental stress is related to the child's problem behavior. These results show that the economic stress of poverty increases parents' parenting stress, which can negatively affect the adaptive development of children in the process of raising children.