• 동서간호학연구지
• /
• 제13권2호
• /
• pp.107-117
• /
• 2007

Purpose: This study was to examine the possibility of the contact with pornographs of elementary school boys and girls and to confirm responses after that, and to compare the feeling of sexual conflict between the boys and girls. Methods: The subjects were 952 5th and 6th graders of elementary school in four city areas(456 boys, 496 girls). Data collection was via questionnaires Results: Except several pupils(34.4% of boys, 27.4% of girls), most of subjects of the study had no contact with pornographs. The response after the contact with pornographs was feeling of shame the most, which was a negative reaction. The sexual conflict appeared more in pupils who had contact with pornographs than in those who had not boys(t=3.84, p<.000), girls(t=3.96, p<.000), which showed a significant difference. However, the conflict between boys and girls was not significant statistically. Conclusion: We would like to suggest that a sound control system must be prepared and a development of programs related to sexual education and promotion of ability fighting against them that can release their impulse of sex.

• Smart Structures and Systems
• /
• 제18권6호
• /
• pp.1125-1143
• /
• 2016

Forced vibration analysis of a simple supported viscoelastic nanobeam is studied based on modified couple stress theory (MCST). The nanobeam is excited by a transverse triangular force impulse modulated by a harmonic motion. The elastic medium is considered as Winkler-Pasternak elastic foundation.The damping effect is considered by using the Kelvin-Voigt viscoelastic model. The inclusion of an additional material parameter enables the new beam model to capture the size effect. The new non-classical beam model reduces to the classical beam model when the length scale parameter is set to zero. The considered problem is investigated within the Timoshenko beam theory by using finite element method. The effects of the transverse shear deformation and rotary inertia are included according to the Timoshenko beam theory. The obtained system of differential equations is reduced to a linear algebraic equation system and solved in the time domain by using Newmark average acceleration method. Numerical results are presented to investigate the influences the material length scale parameter, the parameter of the elastic medium and aspect ratio on the dynamic response of the nanobeam. Also, the difference between the classical beam theory (CBT) and modified couple stress theory is investigated for forced vibration responses of nanobeams.

• 한국해안해양공학회지
• /
• 제13권3호
• /
• pp.195-201
• /
• 2001

본 논문은 파랑중에 다전 계류된 원유저장선에 대한 저주파수 운동을 수치 모사하였다. 시간영역에서의 운동방정식은 충격응답함수를 포함하여 수평면상의 운동 즉 전후, 좌우 및 선수 운동을 고려하였다. 시간영역의 운동방정식에 나타난 부가질량, 파랑감쇠계수, 1차항 파랑 강제력 그리고 2차항 파랑 강제력을 주파수 영역의 특이점 분포법을 사용하여 계산하였고, 다점 계류된 계류삭은 체인이 해저면에 닿은 운동 효과를 포함하여 준 정적 현수선 이론으로 산정되었다. 계산 예로서 장파정 불규칙 파랑 중에 놓인 바아지식 원유저장선에 대한 시간 영역 해석을 수행하였다.

• 한국가스학회지
• /
• 제18권1호
• /
• pp.68-74
• /
• 2014

본 연구에서는 헬멧의 충격응답을 분석하기 위한 단순진동모델을 제시하였다. 실제 헬멧 설계 및 검증과정에서 사용하는 데이터에 기반을 두고 단자유도 진동모델을 채택하였다. 충격에 의한 과도진동응답을 산출하여, 헬멧의 감쇠, 고유진동수, 충돌속도와 같은 인자들이 헬멧의 충격응답에 미치는 영향을 고찰하였다. 최대 G-가속도는 감쇠가 증가함에 따라 감소하였고, 감쇠비가 0.6 이상이 되면 최대 가속도의 값은 변화가 없었다. 고유진동수와 충돌속도에 관하여는 선형적으로 증가하였다. 두부 상해기준(Head Injury Criterion, HIC) 과 최대가속도의 관계도 제시하였다. 본 연구에서의 해석모델이 고품질 경량화 헬멧의 설계과정에서 경제성 제고에 활용될 수 있기를 기대한다.

• Structural Engineering and Mechanics
• /
• 제46권3호
• /
• pp.417-431
• /
• 2013

This paper presents responses of the free end of a cantilever micro beam under the effect of an impact force based on the modified couple stress theory. The beam is excited by a transverse triangular force impulse modulated by a harmonic motion. The Kelvin-Voigt model for the material of the beam is used. The considered problem is investigated within the Bernoulli-Euler beam theory by using energy based finite element method. The system of equations of motion is derived by using Lagrange's equations. The obtained system of linear differential equations is reduced to a linear algebraic equation system and solved in the time domain by using Newmark average acceleration method. In the study, the difference of the modified couple stress theory and the classical beam theory is investigated for the wave propagation. A few of the obtained results are compared with the previously published results. The influences of the material length scale parameter on the wave propagation are investigated in detail. It is clearly seen from the results that the classical beam theory based on the modified couple stress theory must be used instead of the classical theory for small values of beam height.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 춘계학술대회논문집
• /
• pp.920-927
• /
• 2008

This study deals with modeling of Head-Related Transfer Functions (HRTFs) using Principal Components Analysis (PCA) in the time and frequency domains. Four PCA models based on Head-Related Impulse Responses (HRIRs), complex-valued HRTFs, augmented HRTFs, and log-magnitudes of HRTFs are investigated. The objective of this study is to compare modeling performances of the PCA models in the least-squares sense and to show the theoretical relationship between the PCA models. In terms of the number of principal components needed for modeling, the PCA model based on HRIR or augmented HRTFs showed more efficient modeling performance than the PCA model based on complex-valued HRTFs. The PCA model based on HRIRs in the time domain and that based on augmented HRTFs in the frequency domain are shown to be theoretically equivalent. Modeling performance of the PCA model based on log-magnitudes of HRTFs cannot be compared with that of other PCA models because the PCA model deals with log-scaled magnitude components only, whereas the other PCA models consider both magnitude and phase components in linear scale.

• 한국소음진동공학회논문집
• /
• 제18권7호
• /
• pp.746-755
• /
• 2008

This research presents a laboratory study on subjective response of impulsive sound caused by construction site (breaker and blasting). The sources are sampled from outdoor noise and their levels range from 40 to 75 dBA at the interval of 5 dBA. The noise unit is based on A-weighted sound exposure level(ASEL; $L_{AE}$). To make equal ASEL of listening level, finite impulse response(FIR) filter is applied to the originally sampled source to include the effect of propagation attenuation. Sixty-three subjects, forty-two males and twenty-one female, between 18 and 29 years of age, participated in the experiment. The evaluation method of jury test adopted a semantic difference method(SDM). In the test results for impulsive noise, the subjective response of blasting noise was higher than that of breaker noise. The result of %HA that has been combined responses of the three methods except for pink-noise was executed by regression analysis and was shown as the following equation.: $%HA=746.53/(1+{\exp} (L_{AE}-93.3))+0.34$.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권9호
• /
• pp.63-74
• /
• 2020

This study investigates the behavior of foreign investors in the Stock Exchange of Thailand (SET) in the time of coronavirus disease 2019 (COVID-19) as to whether trading is abnormal, what strategy is followed, whether herd behavior is present, and whether the actions destabilize the market. Foreign investors' trading behavior is measured by net buying volume divided by market capitalization, whereas the stock market behavior is measured by logged return on the SET index portfolio. The data are daily from Tuesday, August 28, 2018, to Monday, May 18, 2020. The study extends the conditional-regression model in an event-study framework and extracts the unobserved abnormal trading behavior using the Kalman filtering technique. It then applies vector autoregressions and impulse responses to test for the investors' chosen strategy, herd behavior, and market destabilization. The results show that foreign investors' abnormal trading volume is negative and significant. An analysis of the abnormal trading volume with stock returns reveals that foreign investors are not positive-feedback investors, but rather, they self-herd. Although foreign investors' abnormal trading does not destabilize the market, it induces stock-return volatility of a similar size to normal trade. The methodology is new; the findings are useful for researchers, local authorities, and investors.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권9호
• /
• pp.191-200
• /
• 2020

This research paper examines the causal relationship between India's economic growth and sectoral contribution to Gross Domestic Product (GDP) and vice versa, in the short-run and long-run, over a 10 years time period. Johansen's method of cointegration is used to study the cointegration between the sectoral contributions to Indian GDP vis-à-vis India's economic growth. Further, the route of interconnection between economic growth and sectoral contribution is tested by using Vector Auto Regression (VAR) model. Special attention was given for investigating impulse responses of economic growth depending on the innovations in sectoral contribution using time-series data from 1960 to 2015. This paper highlighted a dynamic co-relationship among industrial sector contribution and agricultural sector contribution and economic development. In the long run, one percent change in industrial sector contribution causes an increase of 3.42 percent in the economic growth and an increase of 1.12 percent in the primary sector contribution, while in the short run industrial and service sector contributions showed significant impact on economic development and agriculture sector. The changing composition of sector contribution is going to be an important activity for the policymakers to monitor and control where the technology and integration of sectors play a significant role in economic development.

• 자원ㆍ환경경제연구
• /
• 제12권2호
• /
• pp.327-346
• /
• 2003

본고는 에너지소비와 경제성장의 관계를 밝히는 데 목적을 둔다. 먼저 에너지 소비, 물가, 실질소득으로 구성된 모형이 안정적임을 확인한 후, 오차수정모형을 이용하여 단기에 있어서 에너지 소비와 소득이 상호 영향을 미쳐 쌍방적 인과관계가 존재함을 보인다. 이와 더불어 예측오차의 분산분해와 충격반응함수를 도입하여 경제성장이 에너지소비를 증가시키나, 에너지소비증가가 경제성장에 미치는 효과는 단기적일 뿐 아니라 물가에 비교적 오랫동안 영향을 미친다는 것을 밝힌다. 이러한 사실은 우리나라의 경우 경제성장으로 에너지 소비가 증가하나, 증가한 에너지 소비가 인플레 등을 통해 경제성장의 장애요인으로 작용할 수 있음을 의미한다.