• 가정∙방문간호학회지
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• 제27권3호
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• pp.330-343
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• 2020

Purpose: This study aimed to describe the meaning of marriage and childbirth among Korean female university students living in the United States, who are influenced both by Korean culture at home and American culture in social contexts. Methods: This qualitative study used phenomenological approaches. Data were collected through individual in-depth interviews with five Korean female university students living in the United States. Data were analyzed using Colaizzi's method to derive the meaning of marriage and childbirth. Results: From the data, 239 meaningful statements, 49 meaning formations, 22 themes, and 12 theme clusters were extracted. Additionally, five major categories emerged. These categories were 1) marriage as an opportunity for self-growth, 2) the mirror of life: parents, 3) oneself who cannot give up, 4) a desire to live a stable life, and 5) ambivalence on the culture of two countries. Conclusion: To improve the positive meaning of marriage and childbirth, a positive role model such as a happy married life of parents at home must be ensured. Finally, institutional strategies should be established to support the balance between home and work, as well as various policies which support women's pregnancy and childbirth.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2000년도 유체기계 연구개발 발표회 논문집
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• pp.82-87
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• 2000

The direct simulation Monte Carlo (DSMC) method is applied to investigate the flow field of a disk-type drag pump. The pumping channels are cut on both sides of a rotating disk. The rotor has 10 Archimedes' spiral blades. In the present DSMC method, the variable hard sphere model is used as a molecular model, and the no time counter method is employed as a collision sampling technique. For simulation of diatomic gas flows, the Larsen-Borgnakke phenomenological model is adopted to redistribute the translational and internal energies.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.1036-1046
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• 2016

We propose a primary water stress corrosion cracking (PWSCC) initiation model of Alloy 600 that considers the stress triaxiality factor to apply to finite element analysis. We investigated the correlation between stress triaxiality effects and PWSCC growth behavior in cold-worked Alloy 600 stream generator tubes, and identified an additional stress triaxiality factor that can be added to Garud's PWSCC initiation model. By applying the proposed PWSCC initiation model considering the stress triaxiality factor, PWSCC growth simulations based on the macroscopic phenomenological damage mechanics approach were carried out on the PWSCC growth tests of various cold-worked Alloy 600 steam generator tubes and compact tension specimens. As a result, PWSCC growth behavior results from the finite element prediction are in good agreement with the experimental results.

• Korea-Australia Rheology Journal
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• 제17권4호
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• pp.149-156
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• 2005

A simple constitutive model for viscoelastic suspensions is discussed in this paper. The model can be used to predict the rheological properties (relative viscosity and all stresses) for viscoelastic suspensions in shear and elongational flow, and the constitutive equations combine a 'viscoelastic' behaviour component and a 'Newtonian' behaviour component. As expected, the model gives a prediction of positive first normal stress difference and negative second normal stress difference; the dimensionless first normal stress difference strongly depends on the shear rate and decreases with the volume fraction of solid phase, but the dimensionless second normal stress difference (in magnitude) is nearly independent of the shear rate and increases with the volume fraction. The relative viscosities and all the stresses have been tested against available experimental measurements.

• Smart Structures and Systems
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• 제16권1호
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• pp.183-194
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• 2015

Shape memory alloy (SMA) helical springs have found a large number of different applications in industries including biomedical devices and actuators. According to the application of SMA springs in different actuators, they are usually under tension and torsion loadings. The ability of SMAs in recovering inelastic strains is due to martensitic phase transformation between austenite and martensite phases. Stress or temperature induced martensite transformation induced of SMAs is a remarkable property which makes SMA springs more superior in comparison with traditional springs. The present paper deals with the simulation of SMA helical spring at room temperature. Three-dimensional phenomenological constitutive model is used to describe superelastic behavior of helical spring. This constitutive model is implemented as a user subroutine through ABAQUS STANDARD (UMAT), and the process of the implementation is presented. Numerical results show that the developed constitutive model provides an appropriate approach to captures the general behavior of SMA helical springs.

• Structural Engineering and Mechanics
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• 제80권5호
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• pp.539-551
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• 2021

With the continuous increase of computational capacity, more and more complex nonlinear elastoplastic constitutive models were developed to study the mechanical behavior of elastoplastic materials. These constitutive models generally contain a large amount of physical and phenomenological parameters, which often require a large amount of computational costs to determine. In this paper, an inverse parameter determination method is proposed to identify the constitutive parameters of elastoplastic materials, with the consideration of both strain rate effect and temperature effect. To carry out an efficient design, a hybrid optimization algorithm that combines the genetic algorithm and the Nelder-Mead simplex algorithm is proposed and developed. The proposed inverse method was employed to determine the parameters for an elasto-viscoplastic constitutive model and Johnson-cook model, which demonstrates the capability of this method in considering strain rate and temperature effect, simultaneously. This hybrid optimization algorithm shows a better accuracy and efficiency than using a single algorithm. Finally, the predictability analysis using partial experimental data is completed to further demonstrate the feasibility of the proposed method.

• Smart Structures and Systems
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• 제4권2호
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• pp.123-135
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• 2008

Damping capacity of SMA damping devices is simulated numerically under distinct geometry and loading conditions. Two-dimensional numerical simulations are performed on the basis of a phenomenological model of dynamics of martensite-austenite phase boundaries. Results of the simulations predict the time delay and the value of the stress transferred to other parts of a construction by a damper device.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.456-458
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• 1997

본 논문에서는 플랜트의 계측신호들에 나타나는 현상적인 특징파형들을 감지하여 플랜트의 고장을 진단하는 기법을 제시하고, 플랜트의 고장시 나타나는 여러 특징 파형들의 전형인 oscillatory 파형을 감지하는 알고리즘을 prediction filtering 기법을 적용하여 얻는 과정을 기술하였다. 또한 이의 구체적 적용 예로 500MW급 화력발전소의 보일러 제어 시스템을 대상으로 여러 고장상황에 대한 고장감지 알고리즘을 설계하였고 제시한 기법의 유용성을 보이기 위한 시뮬레이션 적용 결과를 보였다.

• 한국언론정보학보
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• 제62권
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• pp.179-199
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• 2013

본 연구의 목적은 SNS 이용자들의 투표 인증샷 참여 경험과 인식에 대한 현상학적 분석을 통해 이용자들의 정치참여 의미와 가능성을 도출하는 데 있다. 특히 'SNS 투표 인증샷'에 초점을 둔 이유는 이 행위가 시민의 자발적 정치참여 활동이면서 이용자의 창조적 상상과 집단지성의 의미와 가능성을 표출하고 있기 때문이다. 이론 자원은 뉴미디어 시대의 이용자 행위와 정치적 실천에 관심을 두고 있는 빌렘 플루서의 기술적 상상과 창조적 상상가, 피에르 레비의 집단지성 논의들에 기초한다. 이러한 이론적 논의를 바탕으로 하여 2011년 10.26 서울시장 보궐선거 당시 인증샷 경험을 지닌 SNS 이용자들을 연구참여자로 선정하고 심층인터뷰를 실시한 후 수집된 자료들에 현상학적 분석모형을 적용하고자 한다. 이 때 연구자는 SNS 이용자와 상호주관성의 입장을 견지하여 연구참여자들의 경험에 대한 맥락적 상황을 고려하고, 그들의 체험에 대한 선입견이나 편견을 '괄호치기'한 채 있는 그대로의 현상과 의미 구조에 접근한다. '사태(die Sachen) 그 자체의 의미'를 탐색하는 현상학적 연구는 SNS 이용자들의 정치참여 경험 자체에 초점을 두고 접근하는 '엄밀한 학'이자 방법이기 때문이다.

• 한국보육지원학회지
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• 제10권4호
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• pp.133-158
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• 2014

본 연구는 유아기 자녀를 둔 어머니들의 부모존경-자녀존중 부모교육 프로그램에 참가한 경험을 분석하여 참가과정에서의 의미, 반응 및 변화들을 구체적으로 살펴봄으로써, 어머니들의 체험의 본질에 대해 연구하였다. 이를 위해 9명의 어머니들을 대상으로 총 8회기의 부모존경-자녀존중 부모교육을 실시한 후, 현상학적 이론에 기초하여 프로그램 실시 전후의 면담내용과 프로그램 진행 중에 작성된 저널, 관찰노트의 자료들을 분석하였다. 그 결과, 264개의 의미단위로 묶여 16개의 하위구성요소를 도출하여 분석하였고, 이 가운데 최종 7개의 구성요소가 도출되었다: (1) 부모교육 참가의 내재적 동기, (2) 변화의 시작: 어머니, (3) 변화의 시작: 자녀, (4) 지속되는 갈등, (5) 긍정적인 부모역할모델의 부재와 양육행동의 세대 간 전이, (6) 죄책감에서 벗어나 양육효능감 높이기, (7) 부모교육을 통한 정서적 지원 경험 및 지속적인 교육과정에 대한 기대. 마지막으로 이와 같은 연구결과에 기초하여 향후 과제와 제언을 제시하였다.