• 지역사회간호학회지
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• 제13권1호
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• pp.5-16
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• 2002

Purpose: This study was to compare the stop-smoking rate and nicotine dependency for an adult smoker after implementing the smoking cessation program. Method: Fourty-six adult smokers participated. Self report questionnaire and telephone interview were conducted at the pretest, 6 months later, 1 year later, 2 years later, 3 years later. Result: 1. Stop-smoking rate of smoking cessation program participants was 43.5% 6 months later, 35.6% 1 year later, 24.4% 2 years later, 45.5% 3 years later. 2. The mean of nicotine dependency for continuing smokers was significantly decreased 6 months later(paired-t=4.719, p=.000). 3. The mean of nicotine dependency for continuing smokers was significantly decreased 1 year later(pired-t=4.296=.000). 4. The mean of nicotine dependency for continuing smokers was significantly decreased 2 years later(paired-t=2.778. p=.000). 5. The mean of nicotine dependency for continuing smokers was significantly decreased 3 years later(paired-t=2.795. p=.000). Conclusion: The smoking cessation program was effective to induce cessation in the adult smoker, and to decrease nicotine dependency in the continuing adult smoker.

• Human Ecology Research
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• 제59권3호
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• pp.341-351
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• 2021

The purpose of this study was to examine the longitudinal relationships between Korean adolescents'mobile phone dependency, trajectories of depression, and self-regulated learning abilities. To achieve these goals, structural equation modeling analysis was conducted, using the 3rd, 5th and 7th wave of the data on 4th graders taken from the Korean Children and Youth Panel Survey. The results can be summarized as follows. First, growth-curve longitudinal analysis indicates that depression in 6th through 10th grade has increased. Second, mobile phone dependency among adolescents at 6th grade has a significant effect on both the initial value and the rate of change in depression. Also, the initial value and the rate of change in depression have significant relationships with mobile phone dependency at 10th grade. Moreover, both increased levels of mobile phone dependency and the rate of change in depression significantly influence adolescents'self-regulated learning abilities at 10th grade. Based on a longitudinal data set, these findings demonstrate the causal relationships between Korean adolescents'trajectories of depression and their mobile phone dependency. The findings also provide a comprehensive framework with implications for adolescents'development through an understanding of the relationships between adolescents'depression and mobile phone dependency, which impact their self-regulated learning abilities.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.509-510
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• 2009

• 디지털융복합연구
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• 제14권12호
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• pp.293-302
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• 2016

본 연구는 시간이 경과함에 따라 청소년의 학업긴장과 불행감, 휴대전화 의존이 어떠한 변화 추이를 가지고, 학업긴장의 변화가 불행감과 휴대전화 의존의 변화에 어떠한 종단적 복합적 영향을 파악하여 이들 간의 악순환을 방지하는 방안 모색을 목적으로 한다. 이를 위하여 일반긴장이론을 개념적 연구틀로 설정하고, 한국청소년정책연구원의 제 2~4차 한국아동 청소년패널 1,589명의 청소년 응답치를 사용하여 잠재성장모형 분석을 수행하였다. 분석결과, 청소년의 학업긴장과 불행감, 휴대전화 의존은 모두 시간의 경과에 따라 지속적으로 증가하였다. 학업긴장의 초기값은 불행감의 초기값 및 휴대전화 의존의 초기값과 변화율에는 정적 영향을 미쳤고, 학업긴장의 변화율은 불행감의 변화율에 정적 영향을 미쳤다. 불행감의 변화율은 휴대전화 의존 변화율에 정적 영향을 미쳤다. 또한, 학업긴장의 변화율이 불행감의 변화율을 매개로 하여 휴대전화 의존의 변화율에 정적 영향을 미치는 것으로 나타났다. 이상의 연구결과를 바탕으로 본 연구는 청소년의 학습과 부정적 정서, 휴대전화 의존에 대한 유용한 시사점을 제공하였고, 상기 변수들의 변화의 근거에 대한 후속 연구를 제안하였다.

• 사회복지연구
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• 제44권3호
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• pp.301-322
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• 2013

본 연구는 한국노동패널조사의 1~11차 년도(1998~2008년) 자료를 이용하여 가구특성과 빈곤지속기간이 빈곤탈피에 미치는 영향을 분석하였다. 특히 빈곤지속기간이 경과할수록 빈곤탈피율이 낮아지는 현상이 진정한 지속기간의존성에 의한 것인지 또는 표본이질성에 기인한 것인지를 검증하고 비관찰 이질성을 통제할 때 독립변수의 영향력이 어떻게 달라지는지를 분석하는데 초점을 두었다. 관찰 비관찰 이질성을 통제하면 지속기간의존성이 대부분 사라진다는 분석결과는 겉으로 보이는 지속기간의존성이 사실은 표본이질성으로 인한 가식적 관계임을 의미한다. 또한 비관찰 이질성을 통제한 모형에서는 가구특성의 영향력이 더욱 커졌다. 연령, 교육수준, 가구형태, 가구원 수 등의 인구 사회적 특성과 취업상태 및 종사상 지위 등 경제활동 특성이 빈곤탈피율에 영향을 미친다.

• East Asian Economic Review
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• 제18권1호
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• pp.3-27
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• 2014

This paper examines the effects of financial crises on the long memory volatility dependency of daily exchange returns focusing on the Asian crisis in 97-98 and the Global crisis in 08-09. By using the daily KRW-USD and JPY-USD exchange rates which have different trading regions and volumes, this paper first applies both the parametric FIGARCH model and the semi-parametric Local Whittle method to estimate the long memory volatility dependency of the daily returns and the temporally aggregated returns of the two exchange rates. Then it compares the effects of the two financial crises on the long memory volatility dependency of the daily returns. The estimation results reflect that the long memory volatility dependency of the KRW-USD is generally greater than that of the JPY-USD returns and the long memory dependency of the two returns appears to be invariant to temporal aggregation. And, the two financial crises appear to affect the volatility dynamics of all the returns by inducing greater long memory dependency in the volatility process of the exchange returns, but the degree of the effects of the two crises seems to be different on the exchange rates.

• 대한토목학회논문집
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• 제35권4호
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• pp.769-777
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• 2015

본 연구에서는 속도 의존성을 나타내는 콘크리트의 인장거동을 모사하기 위하여 유변학적(rheological) 모델을 개발하였고 이를 평가하였다. 일반적으로 외부에서 가해지는 하중 속도가 증가할수록 콘크리트의 물성(강도, 탄성계수, 파괴에너지 등)은 그 크기가 증가한다. 콘크리트의 강도는 다른 물성에 비하여 큰 속도의존성을 나타내고, 압축 하중인 경우보다 인장 하중을 받는 경우 그 속도의존성이 크게 나타난다. 이러한 콘크리트의 속도 의존성을 모사하기 위하여, 기존 RBSN(Rigid-Body-Spring-Network) 모델의 거동을 나타내는 스프링 세트에 대쉬포트(Dashpot)와 같은 점성 요소와 Coulomb 마찰 요소를 조합하였다. 요소의 조합에 따라 세 가지 모델( 1)점탄성, 2)점소성, 3)점탄소성 손상(Damage 모델)을 고려하였고, 이에 대한 구성관계식을 유도하였다. 개발된 해석모델은 직접인장 실험의 응력-변형률 관계곡선과 비교 검증되었고, 이중 점탄소성 손상 모델은 실험결과를 잘 모사할 수 있음을 확인하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제46권2호
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• pp.107-114
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• 2023

The purpose of this study was to compare the basic radiological characteristics of in-house polymer gel and commercially-available gel (BANG^TM) gel dosimeters with a spectro-photometer to use a optical computed tomography (CT) scanner. We investigated the radiological characteristics including dose linearity, absorbance spectrum, dose rate dependency and inter-and intra-reproducibility at wavelengths of 590, 600 and 630 nm. The optimal dose linearities of two gel dosimeters showed R² value of 0.939 and 0.948 at wavelengths of 590 nm and 600 nm, respectively. For two polymer gel dosimeters, there is no peak sensitivity within the range of all wavelengths in absorbance spectrum. For in-house gel dosimeter, the dose rate dependency were within 5% for all wavelengths except for the dose rate of 100 MU/min. For BANG^TM gel dosimeter, the dose rate dependency showed an error range of ±5% for all wavelengths. The inter-and intra-reproducibility of two gel dosimeters were within the range of 2.5%. We have confirmed that the two gel dosimeters was appropriate for use with a optical CT scanner.

• Computers and Concrete
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• 제20권1호
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• pp.1-10
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• 2017

This paper focuses on the mesh-size dependency in numerical simulations of reinforced concrete (RC) structures subjected to blast loading. A tensile failure criterion that can minimize the mesh-dependency of simulation results is introduced based on the fracture energy theory. In addition, conventional plasticity based damage models for concrete such as the CSC model and the HJC model, which are widely used for blast analyses of concrete structures, are compared with the orthotropic model that adopts the introduced tensile failure criterion in blast tests to verify the proposed criterion. The numerical predictions of the time-displacement relations at the mid-span of RC beams subjected to blast loading are compared with experimental results. The analytical results show that the numerical error according to the change in the finite element mesh size is substantially reduced and the accuracy of the numerical results is improved by applying a unique failure strain value determined by the proposed criterion.

• 한국연소학회지
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• 제13권2호
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• pp.14-22
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• 2008

The CH* chemiluminescence of premixed flames and their dependency on fuel types has been experimentally investigated on laminar methane and propane premixed flames. The measured chemiluminescence intensities are observed linearly proportional to the fuel flow rate, which could be interpreted as the CH* chemiluminescence signal is linearly proportional to the heat release rate under fuel lean conditions. The effect of equivalence ratio could be expressed by an exponential function as ${I_{CH*}}^{\propto}\;a_1\;{\exp}(b_1{\Phi})$, where $a_1\;=\;0.00054$ and $b_1\;=\;4.60$ for methane and $a_1\;=\;0.0056$ and $b_1\;=\;5.02$ for propane. Oscillating flames showed the temporal fluctuation of chemiluminescence intensity: however, the time averaged values are virtually identical to those of quiescent flames under the same fuel flow rate and equivalence ratio conditions. This observation suggests that there is no significant flame stretch effect on chemiluminescence intensity, in average values.