• 대한간호학회지
• /
• 제47권5호
• /
• pp.663-675
• /
• 2017

Purpose: The purpose of this study was to construct and test a structural equation model of self-management of liver transplant recipients based on self-determination theory. Methods: Participants were 275 outpatients who received liver transplantation. A structured self-report questionnaire was used to assess health care providers' autonomy support, transplant-related characteristics, illness consequence perception, autonomy, competence, family relatedness, depression and self-management. Collected data were analyzed using SPSS/WIN 24.0 and AMOS 24.0 program. Results: The modified model showed a good fitness with the data: GFI=.96, RMSEA=.06, CFI=.96, NFI=.93, TLI=.93, PGFI=.43, PNFI=.49. The health care providers' autonomy support, competence, family relatedness and depression were factors with a direct influence on the self-management of liver transplant recipients. The health care providers' autonomy support and illness consequence perception had an indirect influence through competence, family relatedness and depression. However, the transplant-related characteristics and autonomy did not have a significant effect on self-management. This model explained 59.4% of the variance in self-management. Conclusion: The result suggests that continuous education must be done to promote the competence of liver transplant recipients and to encourage the patient to positively perceive their current health condition with a view that enhances one's self-management. Additionally, the liver transplant recipients should be screened for depression, which would affect self-management. Most of all, health care providers, who have the most influence on self-management, should improve therapeutic communication and try to form a therapeutic relationship with the liver transplant recipients.

• Korean Chemical Engineering Research
• /
• 제45권1호
• /
• pp.32-38
• /
• 2007

통계적인 공정 제어 기법을 회분식 공정에 적용하여, 일반적인 회분식 공정의 데이터를 통해 보다 빠르고, 손쉽게 공정의 상태를 진단할 수 있는 시스템을 구현해 보았다. 대표적인 회분식 공정의 하나인 반도체 식각공정과 반회분식 스타이렌-부타디엔 고무 생산 공정의 데이터를 이용하여 공정 변수와 공정의 상태간의 연관 관계를 규명할 수 있는 모델을 수립하였으며, 이 모델의 출력(output) 결과를 이용해 통계적 공정 제어 차트를 구성하고, 시간에 따른 공정의 추이를 분석해 이상을 판별해 보았다. 회분식 공정의 다축(multi-way) 데이터를 두개의 축으로 만드는 펼치기(unfolding) 과정을 거쳤으며, 모델링 방법으로는 Support Vector Regression 및 Partial Least Square 등의 다변량 회귀분석 방법을 이용하였다. 또한 에러차트 및 변수 기여도 차트(variable contribution chart)를 이용해 이상의 세기, 형태 및 이상 데이터에 대한 각 변수들의 기여도를 계산해 보았으며, 그 결과 이상의 발생 유무 및 발생시점 뿐만아니라 이상의 세기 및 원인 까지 진단해 볼 수 있는 우수한 성능을 보이는 것을 확인할 수 있었다.

• 한국가정과교육학회지
• /
• 제31권3호
• /
• pp.41-55
• /
• 2019

본 연구는 어머니의 한국어능력을 통제한 상황에서 부모의 지지 및 감독이 다문화 청소년의 학교생활적응에 미치는 직접적인 영향과 자아탄력성의 매개효과를 살펴보았다. 본 연구대상은 다문화 가정의 중학교 1학년 자녀로, 한국청소년정책연구원의 다문화 청소년 패널자료 중 어머니가 외국인이고 아버지가 한국인인 국제결혼가정 중학교 1학년 자녀의 자료(1,325명)를 사용하여 분석하였다. 구체적으로, 연구대상 자료에 대해 IBM SPSS 25.0 및 AMOS 25.0 프로그램을 사용하여 기술통계, 상관관계, 일원분산분석, 구조방정식모델 분석이 이루어졌다. 본 연구결과를 요약하면 다음과 같다. 첫째, 부모의 지지 및 감독은 다문화 청소년의 학교생활적응에 직접적으로 정적인 영향을 미쳤으며, 특히 부모의 지지가 다문화 청소년의 학교생활적응에 미치는 영향력이 부모 감독의 영향력에 비해 큰 것으로 나타났다. 둘째, 다문화 청소년의 자아탄력성은 부모의 지지 및 감독과 학교생활적응 간의 관계를 모두 매개함으로써 부분 매개효과가 제시되었다. 마지막으로 본 연구결과 다문화 가정 중학교 1학년 자녀의 학교생활적응에 있어 부모의 양육행동 및 자아탄력성의 영향이 규명됨에 따라 다문화 청소년의 자아탄력성 수준을 높이고, 학교생활적응을 지원하기 위해 학교와 지역사회기관이 연계한 부모교육 실시의 필요성 및 가정과 교과의 역할을 제시하였다.

• 한국융합학회논문지
• /
• 제5권1호
• /
• pp.9-15
• /
• 2014

교통사고는 다양한 요인으로 인해 발생한다. 그 중에는 교통사고가 발생할 당시의 기상상태가 있다. 기상상태에 따라 교통사고로 인해 발생하는 사망자의 비율은 차이가 있다. 교통사고로 인한 사망자의 수를 줄이려면 기상 상태에 따라 발생될 교통사고 발생 수를 예측 하는 것이 필요하다. 본 논문은 기상 상태에 따른 교통사고 발생 빈도수를 예측하는 모델링을 제안한다. 예측 모델링의 이론으로는 마코프 프로세스를 적용하였다. 제안된 모델링에 실제 데이터를 적용하여 교통사고 발생 수를 예측 하였고, 실제 발생 수와 비교하였다. 본 논문은 기상 변화에 따른 교통사고 정책수립에 도움을 줄 것이다.

• 산업기술연구
• /
• 제21권B호
• /
• pp.281-286
• /
• 2001

In this study, product design and prototype manufacturing of a plastic water-pump pulley has been tried. The designed model is supposed to be made of 33 % glass reinforced resin of which the tensile strength is 180 MPa, and has 24 ribs on each side to increase its structural strength. Structural analysis under a static load of 300 kgf acting on both edges of the belt has been carried out using a commercial finite element code, MARC. The analysis result showed the maximum effective stress near a rib of designed model would be at most 35 MPa (less than 20% of the tensile strength), therefore, the plastic product would be sufficiently safe under that loading condition. On the basis of the structural analysis, a prototype of the designed model has been manufactured by using the fused deposition modelling (FDM) method which is one of the rapid prototyping (RP) methods, using ABS resin and support materials. The CAD data exported to the RP system in STL format was prepared by a commercial solid modeling software, SolidWorks. It has been proved that the plastic pulley can successfully replace the existing flow-formed steel product.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2011년 춘계학술대회논문집
• /
• pp.124-128
• /
• 2011

The heat transfer rate in an oven is very important for the quality of cooking food. For a robust performance design in an electric oven, forced convection has been used rather than natural convection, in bake and convection mode. Forced convection heat trans for in a vented electric oven has been numerically evaluated using the commercial software FLUENT. CFD modeling of the electric oven involves three-dimensional, steady state, MRF fan model and DO radiation model. In this study, the electric oven cavity and fan modules are not simplified. Other research shows that the boundary condition can often lead to non-physical solutions, such as reverse flaw at the top vent. To remove this non-physical solution, control volume has been expanded at the nearby vent. This numerical analysis has been performed with dedicated experimental support. The results show that there is less than a 2.2% difference between the simulation and experimental data for the temperature profile of food. From this research we can use this oven simulation technique to make a better convection system in an electric oven.

• ETRI Journal
• /
• 제33권3호
• /
• pp.382-392
• /
• 2011

This paper proposes the streaming radio frequency identification (RFID) protocol to support robust data streaming in a passive communication, which is extended from the ISO18000-6 Type C RFID standard. By observing and modeling the unique bit error behavior through detailed analysis in this paper, we found that performance is significantly limited by inaccurate and unstable link frequencies as well as low SNR which are inevitable for passive devices. Based on the analysis, we propose a simple and efficient protocol to adaptively insert extra error control sequences in a packet for tolerating tough link condition while maximizing the throughput and preserving the minimal implementation cost. To evaluate effectiveness of our proposal in real-time streaming applications, we experimented on real-time H.264 video streaming and prototyped the system on FPGA. To our best knowledge, our paper is the first work to take analytical approach for maximizing the throughput and demonstrate the possibility of the realtime multimedia streaming transmission in the passive RFID system.

• 대한토목학회논문집
• /
• 제28권3A호
• /
• pp.367-373
• /
• 2008

국내/외에서 설계되는 강곡선거더교 복부판의 전단강도는 복부판의 4변을 단순지지라는 가정 하에서 산정되는 탄성전단좌굴강도로 제안하고 있다(AASHTO Guide Specifications, 2003). 그러나, Lee et al.(1996, 1999)과 Bradford(1996)의 최근 연구에서 실제의 설계범위를 갖는 직선이나 곡선 복부판에서 어느 정도의 강성을 갖는 플랜지에 의해서 접하는 변의 경계조건은 단순지지 보다는 고정지지에 더 근접하며, 복부판의 형상비에 따라서는 AASHTO의 탄성좌굴강도가 60%이상 낮게 평가되고 있음을 발표하였다. 특히 강곡선복부판의 전단좌굴강도는 곡률의 영향으로 AASHTO Guide Specifications(2003)의 탄성전단좌굴강도보다 최대 38%이상 증가하고 있음이 Lee and Yoo(1999)의 연구에서 조사되었다. 본 논문에서는 선형좌굴해석을 이용하여 곡률과 경계조건이 동시에 고려된 강곡선 복부판의 전단좌굴계수를 합리적으로 추정할 수 있는 산정식을 제안하고자 한다.

• Advances in aircraft and spacecraft science
• /
• 제7권6호
• /
• pp.553-570
• /
• 2020

To address the problems caused by the strong coupling of an airbreathing hypersonic vehicle's airframe and propulsion to the integrated control system design, an integrated airframe-propulsion model is established, and the coupling characteristics between the aircraft and engine are analyzed. First, the airframe-propulsion integration model is established based on the typical nonlinear longitudinal dynamical model of an air-breathing hypersonic vehicle and the one-dimensional dual-mode scramjet model. Thrust, moment, angle of attack, altitude, and velocity are used as transfer variables between the aircraft model and the engine model. The one-dimensional scramjet model can accurately reflect the working state of the engine and provide data to support the coupling analysis. Second, owing to the static instability of the aircraft model, the linear quadratic regulator (LQR) controller of the aircraft is designed to ensure attitude stability and height tracking. Finally, the coupling relationship between the aircraft and the engine is revealed through simulation examples. The interaction between vehicle attitude and engine working condition is analyzed, and the influence of vehicle attitude on engine safety is considered. When the engine is in a critical working state, the attitude change of the aircraft will not affect the engine safety without considering coupling, whereas when coupling is considered, the attitude change of the aircraft may cause the engine unstart, which demonstrates the significance of considering coupling characteristics.

• International Journal of Automotive Technology
• /
• 제8권3호
• /
• pp.375-382
• /
• 2007

The multi-driver off-road vehicle drive-line consists of many components, with close connections among them. In order to design and analyze the drive-line efficiently, a modular methodology should be taken. The aim of a modular approach to the modeling of complex systems is to support behavior analysis and simulation in an iterative and thus complex engineering process, by using encapsulated submodels of components and of their interfaces. Multi-driver off-road vehicles are comparatively complicated. The driving-line is an important core part to the vehicle, it has a significant contribution to the performance. Multi-driver off-road vehicles have complex driving-lines, so performance is heavily dependent on the driving-line. A typical off-road vehicle's driving-line system consists of a torque converter, transmission, transfer case and driving-axles, which transfers the power generated by the engine and distributes it effectively to the driving wheels according to the road condition. According to its main function, this paper proposes a modularized approach for design and evaluation of the vehicle's driving-line. It can be used to effectively estimate the performance of the driving-line during the concept design stage. Through an appropriate analysis and assessment method, an optimal design can be reached. This method has been applied to practical vehicle design, it can improve the design efficiency and is convenient to assess and validate the performance of a vehicle, especially of multi-driver off-road vehicles.