• 한국보육지원학회지
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• 제17권6호
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• pp.93-108
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• 2021

Objective: This study examined the mediating effect of adolescents' self-esteem on the relationship between their childhood abuse experiences and school rule-breaking behavior. Methods: The research participants consisted of 1,748 adolescents aged from 15 to 16. Adolescents' school rule-breaking behavior and self-esteem were measured in 2016, whereas their childhood abuse experiences were measured in 2010. Panel data collected by the National Youth Policy Institute were analyzed using the bootstrapping technique and PROCESS Macro for SPSS. Results: The results of the study are as follows. First, the adolescents' childhood abuse experiences affected their school rule-breaking behavior. That is, the adolescents who were abused by their parents were at higher risk of breaking school rules later in life. Second, the adolescents' self-esteem mediated the relationship between their childhood abuse experiences and school rule-breaking behavior. The adolescents who were abused by their parents tend to have low levels of self-esteem and thereby break school rules. Conclusion/Implications: The present study shows the possibility that childhood abuse experiences lead to adolescents' problematic behaviors, such as school rule violation. It also indicates that it is necessary to provide counseling and therapeutic interventions for enhancing the self-esteem of adolescents of the at-risk group with childhood abuse experiences.

• 근관절건강학회지
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• 제29권2호
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• pp.133-140
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• 2022

Purpose: This study was to examine the effects of auricular acupressure on competitive state anxiety and the accuracy of breaking in taekwondo players. Methods: This study was a quasi-experimental study with a time-series design. Twenty-two taekwondo breaking players were assigned to the control group for the first two weeks and then assigned to the experimental group for the next two weeks. Anxiety was measured by the revised Competitive State Anxiety Inventory-2 and the accuracy of breaking was measured as a percentage of breaking the wooden board. Results: Auricular acupressure for two weeks significantly increased the accuracy of breaking from 80.83±7.99% to 90.92±7.57% (t=7.74, p<.001). Auricular acupressure for two weeks significantly increased anxiety from 35.66±10.36 to 50.64±7.45 (t=4.38, p<.001). Among three subtypes of competitive state anxiety, somatic anxiety was increased from 12.48±4.97 to 22.95±4.54 (t=2.09, p=.011). Cognitive anxiety was significantly increased from 10.11±3.96 to 14.68±3.89 (t=5.37, p<.001) but self-confidence was not changed. Conclusion: The results of this study showed that auricular acupressure was effective in increasing the accuracy of breaking in taekwondo players.

• Journal of Mechanical Science and Technology
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• 제19권11호
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• pp.2077-2081
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• 2005

A symmetry breaking nonlinear fluid flow in a two-dimensional wall-driven square cavity taking symmetric boundary condition after some transients has been investigated numerically. It has been shown that the symmetry breaking critical Reynolds number is dependent on the time history of the boundary condition. The cavity has at least three stable steady state solutions for Re=300-375, and two stable solutions if Re>400. Also, it has also been showed that a particular solution among several possible solutions can be obtained by a controlled boundary condition.

• 한국해양공학회지
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• 제19권2호
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• pp.29-33
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• 2005

The accuracy of predicting wave transformation in the nearshore is very important to wave hydrodynamics, sediment transport, and design of coastal structures. Numerical experiments are conducted to identify the shoaling and breaking characteristics of a fully nonlinear Boussinesq equation-based model. Simulated shoaling showed good agreement with the Shouto's formula, and the results of the breaking experiment agreed well with experimented data, over several beach profile.

• 한국해안·해양공학회논문집
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• 제32권6호
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• pp.384-395
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• 2020

연안에서 천수변형에 의해 발생하는 쇄파는 표사이동, 연안류의 생성, 충격파압의 발생 등과 같은 연안역의 다양한 물리현상과 밀접한 관계를 갖고 있다. 따라서, 연안구조물의 설계 시 쇄파파고 및 쇄파수심과 같은 쇄파지표를 정확하게 예측하는 것이 중요하다. 과거부터 많은 연구자들에 의해 쇄파현상을 규명하고 예측하기 위한 많은 과학적인 노력들이 이루어져 왔다. 대표적인 쇄파에 연구들은 주로 수리모형실험을 통해 쇄파지표 예측을 위한 많은 경험식이 제안되어 왔다. 하지만, 기존의 쇄파지표에 대한 경험식은 일정한 방정식의 가정하에 자료의 통계적 분석을 통해 가정한 방정식의 계수들을 결정하고 있다. 본 논문에서는 회귀 혹은 분류문제와 관련된 다양한 연구분야에 있어서 높은 예측성능을 보여주는 대표적인 선형기반의 지도학습 머신러닝 기법을 적용하였다. 적용된 머신러닝 기법을 기반으로 기존의 쇄파에 대한 실험자료로부터 쇄파지표 예측을 위한 모델을 개발하고, 학습된 모델로부터 쇄파예측을 위한 새로운 선형식을 제시하였다. 새롭게 제안된 쇄파지표식은 단순한 선형식임에도 불구하고 기존의 경험 공식에 비해 유사한 예측성능을 보였다.

• 한국해안·해양공학회논문집
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• 제27권6호
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• pp.406-418
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• 2015

기존 FUNWAVE-TVD 버전 2.1 모형을 수정한 본 모형의 검증을 위해 고립파 실험, Vincent and Briggs(1989)의 비쇄파 및 쇄파 실험, Luth et al. (1994)의 수리실험을 수행하였다. 쇄파 실험의 경우 기존 결과와 비교하기 위하여 eddy viscosity를 이용한 쇄파 방법도 포함하였다. Eddy viscosity 쇄파 방법을 이용하여 Vincent and Briggs(1989)의 쇄파 실험에 적용한 결과 수정된 모형에서는 수중천퇴 중심의 y축을 기준으로 파랑류(wave-induced current)의 대칭성이 유지되었으나 FUNWAVE-TVD 버전 2.1 모형에서는 대칭성이 유지되지 않았다. 또한 eddy viscosity 쇄파 방법을 이용한 경우가 천수방정식으로 전환하여 쇄파를 모의하는 방법보다 관측치에 더 가깝다. 그리고 FUNWAVE-TVD 버전 2.1 모형에 사용한 기법들과 비교하기 위하여 Erduran et al.(2005)이 제시한 4차 정확도의 MUSCL-TVD 기법과 minmod limiter를 이용한 3차 정확도의 기법을 적용하여 고립파의 전파 양상을 비교 검토하였다.

• Journal of Ship and Ocean Technology
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• 제5권2호
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• pp.50-61
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• 2001

In this paper, nonlinear interactions between water waves and a horizontally submerged circular cylinder are numerically simulated. In this case, the nonlinear interactions between them generated a wave breaking phenomenon. The wave breaking phenomenon plays an important role in the wave farce. Negative drifting forces are raised at shallow submerged cylinders under waves because of the wave breaking phenomenon. For the numerical simulation, a finite difference method based on the unsteady incompressible Navier-Stokes equations and the continuity equation is adopted in the rectangular grid system. The free surface is simulated with a computational simulation method of two-layer flow by using marker density. The results are compared with some existing computational and experimental results.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권4호
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• pp.404-417
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• 2017

The present study numerically analyzed the dynamic behavior of 3D framed structures subject to impulsive slamming forces by violent breaking waves. The structures were modeled using multiple lumped masses for the vertical projections of each member, and the slamming forces from the breaking waves were concentrated on these lumped masses. A numerical algorithm was developed to properly incorporate the slamming forces into a dynamic analysis to numerically determine the structural responses. Then, the validity of the numerical analysis was verified using the results of an existing hydraulic experiment. The numerical and experimental results for various model structures were generally in good agreement. The uncertainties concerning the properties of the breaking waves used in the verification are also discussed here.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 추계학술대회 논문집
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• pp.226-231
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• 2003

The viscous interaction of stern wave is studied by simulating the free-surface flows, including sub-breaking phenomena around a high speed catamaran hull advancing on calm water. The Navier-Stokes equation is solved by a finite difference method where the body-fitted coordinate system, the wall function and the triple-grid system are invoked. The numerical appearance of the sub-breaking waves is qualitatively supported by the experimental observation They are also applied to study precisely on the stern flow of S-103 as to which extensive experimental data are available. For the catamaran, computations are carried out for the mono ana twin hulls.

• 대한가정학회지
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• 제35권1호
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• pp.257-262
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• 1997

In this thesis considering the problems shown in the usage of interlining of clothes and in the process of sewing the breaking away strength which is meant by adhesion is analysed by experimennt in which Polyamide content is dealed with at the 5 level to raise the adhesive strength by using the one-sided non woven adhesive interlining made in this country as the samples. After examing the optimum in the process of Cotton and polyester fabrics and adhered fabrics practical for blouse and jacket and analysing the breaking away strength the wanted property of matter and the change with the repeated laundry We reach at the following results. 1. The adhesive strength of the two adhered fabrics were strongly appeared in order of cotton>polyester. 2. The order of the breaking away strength by the interlinings of adhesive fabrics was A5> A4> A3> A2> A1. 3. The breaking away strength of the two adhered fabrics was weakened by the repeated laundry and the breaking away phenomena were fewer under the most suitable conditions than the various conditions.