• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.305-309
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• 2013

본 연구에서는 유체역학적인 후류 효과를 제어하고 항력을 이용하여 구체를 안정적으로 부양하는 방법을 해석 및 실험적으로 고찰하였다. 물체를 공중에 부양할 때는 물체가 받는 중력과 제트에 의하여 공급되는 항력이 평형을 이루어야 한다. 이 때 공기의 흐름의 레이놀즈 수에 따라 공기가 구체를 지나가며 구체후면에 생기는 후류에 의하여 부양상태가 불안정하게 될 수 있다. 구체의 운동이 제트에 의하여 안정되는 현상은 베르누이 및 코안다 효과로 설명할 수 있다. 에디슨을 이용하여 레이놀즈 수에 따른 실린더에 작용하는 항력과 후류에 의한 불안정화 힘을 해석적으로 구하였으며 이를 실험적으로 고속카메라를 이용하여 부양 거리, 안정도 등을 측정하여 비교하였다. 고찰 결과 레이놀즈 수가 작을수록 더 안정됨을 확인하였다.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.501-506
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• 2016

The purpose of this paper was to explore the effects of familism and sense of intimacy on Filial responsibility of women. This survey was conducted from March, 2014 to June, 2014 and 422 responses from the survey were used for the analysis. The research findings could be summarized as the followings. First, the mean of filial responsibility, familism and sense of intimacy were higher than average. Especially, the mean score of filial responsibility showed significantly higher score. Second, both of familism and sense of intimacy, income were the significant predictors to explain filial responsibility. So, filial responsibility has been kept and both of familism and sense of intimacy were revealed as significant factors to filial responsibility.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.6
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• pp.780-787
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• 2012

In general, the ocean wave vibration power generator consists of buoy, vibration system and linear generation system. It maximized energy efficiency by using resonance phenomenon that turned to the natural frequency of vibration system and frequency of ocean wave energy. But it is difficult to obtain efficiently energy from ocean wave because the frequency of ocean wave changes from moment to moment. In this paper, we study the buoy and vibration system of ocean wave power generator to solve these problem. Firstly, we designed the buoy that gives rise to resonance between ocean wave and buoy. Secondly, we designed vibration system that is occurred to resonance between buoy and vibration system. And then the relative velocity between the buoy and magnetic of ocean wave vibration generator increases and the relative displacement between buoy and ocean wave decreases at the same time. As a result, the method which is proposed in this paper has merits not only securing its stability from harsh ocean wave environment but also obtaining more kinetic energy from ever-changing ocean wave.

• The Journal of the Acoustical Society of Korea
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• v.37 no.6
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• pp.422-427
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• 2018

The purpose of this study is to investigate the effect of acoustic radiation force on the standing wave acoustic levitation phenomenon, which is the levitation of small objects near the pressure node of the standing wave, using the Bernoulli principle. The source and scheme of the acoustic radiation force, which is the cause of the levitation, are conceptually explained through comparison with the graph of the acoustic radiation force versus the distance from the transducer. A series of experiments supporting this explanation was performed with a BLT(Bolt-clamped Langevin Type) ultrasonic transducer to confirm that the objects are floating near the pressure nodes and that it satisfies the condition for the standing wave formation when the object is levitating. Furthermore, the vertical alignment of floating objects, which is a characteristic of standing wave acoustic levitation phenomenon, could be explained.

• Korea journal of population studies
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• v.29 no.1
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• pp.209-239
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• 2006

본 연구는 총부양비를 최소화하는 적정인구성장률을 인구학적 부양비와 경제적 부양비로 나누어 계산하구 그것이 무엇을 의미하가를 연구하는 것이 목적이다. 이 연구를 위하여 연구모형을 제시하고, 합계출산율과 적정인구성장률의 관계를 명시하며, 그것이 궁극적으로 적정인구 규모에 어떤 의미를 갖는가를 탐색한다. 인구학적 부양비를 최소화하는 인구성장률은 $-0.03%{\sim}0.15%$의 범위에 있으며, 그것은 합계 출산율로는 $2.1{\sim}2.2$명에 해당한다. 경제적 부양비를 최소화하는 인구성장률은 유년층과 노년층의 상대적 개인 소비비중에 따라 인구성장률과 그것이 함의하는 합계출산율은 달라진다. 예컨대, $u_1:u_3=2:1$일 때 적정인구성장률은 $-1.17{\sim}-0.93%$, 그것이 함의하는 합계출산율은 $1.5{\sim}1.6$명이다. 한편 유년층 대비 노년층의 상대적 소비비중이 증가하는 경우에는 적정인구성장율이 높아져야 한다. 예컨대 $u_1:u_2=1:1.2$일 때 적정인구성장률은 $0.42{\sim}0.45%$이고, 그것이 함의하는 합계출산율은 $2.3{\sim}2.4$명이다. 본 연구에서 적정인구추계를 위한 기초 여론조사에 따라 진행된 상대적 소비비중을 계산한 결과에 따르면, 유년층과 노년층의 상대적 개인 소비비중은 $u_1:u_2=1.25:1$이며, 이에 따른 현재의 상황에서 한국의 적정출산율은 $1.9{\sim}2.0$명 수준으로, 이에 해당하는 적정인구성장률은 대략 약간의 네거티브 성장을 하는 경우라고 할 수 있을 것이다.

• Korea journal of population studies
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• v.25 no.1
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• pp.83-111
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• 2002

This study examines the structure of intergenerational relationship and its effects on old-age security of the Korean society. Of interest is the effects of the middle aged's attitudes on old parents'security on their intergenerational exchange relationship and on their own old-age security as well. This study also attempts to test the applicability of the social exchange perspective to the study of intergenerational support relationship in Korea The social exchange perspective considers intergenerational relationship as an exchange of aids and rewards between generations. However due to strong norm of filial duty and inadequate welfare system, supporting old parents is regarded as younger generation's duty in Korea This study utilizes a survey data conducted by Kim et al.(2000). Major findings can be summarized as follows. First, the middle aged who gives one-sided supports to their parents tends to have the traditional attitude on old parents' security. It implies that intergenerational support relationship in Korea is not consistent with the explanations from the social exchange perspective. This study suggests a 'chained reward system'as an altermative explaining the intergenerational relationship. Second, an absolute majority of the middle aged tend to think that they are responsible for their own old-age security regardless of the pattern of intergenerational support relationship and attitudes on old parents' security. It implies that the middle aged in Korea holds the status of 'marginal men' who supports their parents but can't take the similar supports from their children.

• 한국노년학
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• v.25 no.2
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• pp.127-141
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• 2005

Prior studies about nursing home placement identified factors contributing to the risk of institutionalization by pooling adult child caregivers and spousal caregivers together, regardless of differential challenges for the two types of caregivers. In a sample of 456 caregivers followed for a 2 year period, an event history analysis showed that relationship made difference in time to placement and that differential factors led to institutionalization for spousal caregivers and daughter caregivers. Spousal caregivers are more likely to place dementia patients into nursing homes sooner than adult child caregivers. The age of care recipients and role captivity (refers to being unwilling, involuntary incumbent of a caregiver role) are predictors of placement for both groups of caregivers. Dementia patients who were older had a greater risk of institutionalization. Greater feelings of role captivity also shortened the time to placement. Income and education are significant predictors only for caregiving daughters. Daughters who had a high education level are more likely to delay nursing home placement whereas those who had a higher income are more likely to institutionalize their demented parents sooner. Use of day care and behavioral problems are significant predictors only for spousal caregivers. Specifically, use of day care and behavioral problems precipitates nursing home placement. The findings of this study suggest that interventions for helping family members to provide care to the demented elderly at home must consider different circumstances faced by caregiving spouses and caregiving daughters.

• 한국노년학
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• v.29 no.2
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• pp.611-627
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• 2009

The purpose of this study is to compare in the U.S. and Korea regarding adult children's quality of relationship and care provision for their elderly parents. The study sample consist of 320 adult children in the U.S. and 554 adult children in Korea with at least one parent living. The U.S. study sample is drawn from the State of California, and the Korean sample is drawn from Gyeongsangnamdo Province. The study result shows that the U.S adult children score higher than the Korean adult children in the quality of relationship measure for their elderly parents. And Korean adult children score higher than the U.S. adult children in the care provision measure for their elderly parents. It is found that the most significant factor influencing American adult children's care provision is caregiving attitude for elderly parents, while for Korean adult children, it is the quality of the relationship between adult children and elderly parents. This study results can serve as a foundation for understanding the U.S. and Korean differences regarding adult children's support for their elderly parents and for providing a solution to caregiving issues for elderly parents.

• 한국보건간호학회:학술대회논문집
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• 1997.12a
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• pp.48-49
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• 1997

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.555-563
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• 2016

This study examined the economic burden of middle age householders supporting their family. They could not prepare for their later life because they are supporting their parents and children in their unstable employment. This study examined how to decrease the burden of middle age householders. Using the Korea Welfare Panel Study, this study analyzed data by hierarchical regression. The result showed that age, gender, education, unemployed, ownership of the house, number of employees, monthly income, and family relationship satisfaction had an effect on the economic burden of support by middle age householders. Based on the result, the researchers offered political suggestions for decreasing the levels of economic burden of support by middle age householders.