• Journal of Korean Academy of Nursing
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• v.34 no.5
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• pp.722-728
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• 2004

Purpose: This study was designed to determine the predictors of postpartum depression. Method: One hundred-sixty one women within one year after delivery from one public health center located in the northern area of Seoul were used in this study. The instruments were a survey of general characteristics, the Edinburgh Postnatal Depression Scale, recent life events index, perceived social support from family, Quality of marriage index, parenting stress index, and Rosenberg's self-esteem inventory. Data was analysed using descriptive statistics, Pearson correlation coefficients, and logistic regression. Result: The average item score of the EPDS was 6.67. 12.4% of respondents, who scored above a threshold 12, were likely to be suffering from a depression of varying severity. The fitness of the model for explaining postpartum depression from six variables, plan for pregnancy, family support, quality of marital relation, perceived social support, life events, childcare stress, and self-esteem, was statistically significant and the predictive power of these variables was 90.9%. The significant predictors of postpartum depression were family support and child care stress. Conclusion: Further research is needed to identify the prevalence rate of postpartum depression using more reliable sampling methods from a large general population. Nursing interventions need to be developed for promoting family support and reducing childcare stress.

• Journal of Korean Academy of Nursing
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• v.43 no.4
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• pp.486-496
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• 2013

Purpose: The purpose of this study was to identify the awareness of child rearing among parents of children in early childhood and to provide fundamental data for parent education programs according to child rearing type. Methods: Q-methodology which provides a method of analyzing the subjectivity of each item was used. Forty Q items which were derived from a literature review and interviews with nurturing mothers were classified into a normal distribution using a 9-point scale. Collected data were analyzed using the QUANAL PC Program. Results: Four types of parents' child rearing were identified. Type I was named 'affection-respect type', type II, 'concern-rule compliant type', type III, 'solicitude-model type', and type IV, 'geniality-encouragement type'. Conclusion: For proper growth and development during early childhood, parents should have rational information and awareness of their child rearing type. Results of this study can be used as essential data to develop child rearing education programs according to parents' child rearing attitude.

• Journal of Nutrition and Health
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• v.35 no.6
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• pp.668-680
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• 2002

The purpose of this study was to investigation the importance and categorization of task elements of school food service dietician and to provide the useful data for standard model of the dietician′s tasks of school foodservice. This study was conducted in school food services nationwide in method of written questionnaire. The questionnaires were mailed to the dieticians of 3 type school foodservice system-conventional, commissary, joint management. Of the 660 schools that participated in this study, the responses from 212 conventional system and 212 commissary system and 200 joint management system were selected for analysis. Statistical analysis was performed with SAS/Win 6.12 package program for descriptive analysis, T-test, ANOVA, factor analysis using. The main results of this study can be summarized as follows Importance level was more than 4 score out of 5 scale in most of the task elements. The result was indicative of the appropriateness of definition of the 61 task elements. Of 61 task elements, importance level on ′nutrition education′ and on ′evaluation of foodservice operation management′ indicated the most significant difference between present and ideal situation. Through factor analysis, 61 task elements were regrouped into 7 dimensions; "Duty dimension of cooking and distribution management", "Duty dimension of cost management", "Duty dimension of raw material management", "Duty dimension of education management", "Duty dimension of menu management", "Duty dimension of record keeping of foodservice", "Duty dimension of general management (others)".

• BMB Reports
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• v.46 no.8
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• pp.391-397
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• 2013

The ATP-inhibited Plant Mitochondrial $K^+$ Channel ($PmitoK_{ATP}$) was discovered about fifteen years ago in Durum Wheat Mitochondria (DWM). $PmitoK_{ATP}$ catalyses the electrophoretic $K^+$ uniport through the inner mitochondrial membrane; moreover, the co-operation between $PmitoK_{ATP}$ and $K^+/H^+$ antiporter allows such a great operation of a $K^+$ cycle to collapse mitochondrial membrane potential (${\Delta}{\Psi}$) and ${\Delta}pH$, thus impairing protonmotive force (${\Delta}p$). A possible physiological role of such ${\Delta}{\Psi}$ control is the restriction of harmful reactive oxygen species (ROS) production under environmental/oxidative stress conditions. Interestingly, DWM lacking ${\Delta}p$ were found to be nevertheless fully coupled and able to regularly accomplish ATP synthesis; this unexpected behaviour makes necessary to recast in some way the classical chemiosmotic model. In the whole, $PmitoK_{ATP}$ may oppose to large scale ROS production by lowering ${\Delta}{\Psi}$ under environmental/oxidative stress, but, when stress is moderate, this occurs without impairing ATP synthesis in a crucial moment for cell and mitochondrial bioenergetics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.3
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• pp.230-237
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• 2004

Lane Sensing techniques based on vision sensors are regarded promising because they require little infrastructure on the highway except clear lane markers. However, they require more intelligent processing algorithms in vehicles to generate the previewed roadway from the vision images. In this paper, a lane sensing algorithm using vision sensors is developed to improve the sensing robustness. The parallel stereo-camera is utilized to regenerate the 3-dimensional road geometry. The lane geometry models are derived such that their parameters represent the road curvature, lateral offset and heading angle, respectively. The parameters of the lane geometry models are estimated by the Kalman filter and utilized to reconstruct the lane geometry in the global coordinate. The inverse perspective mapping from the image plane to the global coordinate considers roll and pitch motions of a vehicle so that the mapping error is minimized during acceleration, braking or steering. The proposed sensing system has been built and implemented on a 1/10-scale model car.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.356-361
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• 2003

The objective of this study is a qualitative comparison between line-integrated OH chemiluminescence ($OH{\ast}$) image and its Abel inversion image at different phase of the oscillating pressure field. PIV(Particle Image Velocimetry) measurements were conducted under non-reacting conditions to see the global flow structure. Also NOx emission was measured to investigate the effect of fuel-air premixing on combustion instability and emission characteristics. Experiments were carried out in an atmospheric pressure, laboratory-scale dump combustor operating on natural gas. Combustion instabilities in present study exhibited a longitudinal mode with a dominant frequency of ${\sim}341.8$ Hz, which corresponded to a quarter wave mode of combustor. Heat release and pressure waves were in-phase when instability occurred. Results gave an insight about the location where the strong coherence of pressure and heat release existed. Also an additional information on active control to suppress the combustion instabilities was obtained. For lean premixed combustion, strong correlation between $OH{\ast}$ and NOx emissions was expected largely due to the exponential dependence of thermal NOx mechanism on flame temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.211.2-211.2
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• 2014

Epitaxial complex oxide thin film heterostructures have attracted a great attention for their multifunctional properties, such as ferroelectricity, and ferromagnetism. Two dimensional electron gas (2DEG) confined at the interface between two insulating perovskite oxides such as LaAlO3/SrTiO3 interface, provides opportunities to expand various electronic and memory devices in nano-scale. Recently, it was reported that the conductivity of 2DEG could be controlled by external electric field. However, the switched conductivity of 2DEG was not stable with time, resulting in relaxation due to the reaction between charged surface on LaAlO3 layer and atmospheric conditions. In this report, we demonstrated a way to control the conductivity of 2DEG in non-volatile way integrating ferroelectric materials into LAO/STO heterostructure. We fabricated epitaxial Pb(Zr0.2Ti0.8)O3 films on LAO/STO heterostructure by pulsed laser deposition. The conductivity of 2DEG was reproducibly controlled with 3-order magnitude by switching the spontaneous polarization of PZT layer. The controlled conductivity was stable with time without relaxation over 60 hours. This is also consistent with robust polarization state of PZT layer confirmed by piezoresponse force microscopy. This work demonstrates a model system to combine ferroelectric material and 2DEG, which guides a way to realize novel multifunctional electronic devices.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.359-359
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• 2011

기존 수자원계획에 있어서 수문량 예측은 매우 제한적으로 활용되고 있는 실정으로서 최근 기후변화 및 이상기후로 기인하는 기상학적 불확실성 증가에 대해서 효과적으로 대응 하기가 어렵다. 본 연구에서는 기상인자를 활용한 수문변량 예측기법을 개발하고자 하며 국내에 수문자료가 충분한 지역에 대해서 모형의 적합성과 타당성을 평가하고자 한다. 대부분의 수문변량은 해수면온도, 해수면기압, 바람장 등 Large Scale의 기상학적 특성과 연관성을 가지고 있으며 선행시간을 가지고 수문순환에 영향을 주고 있다. 수문변량과 기상학적 변량사이에는 일반적으로 비선형 관계를 가지고 있는 것으로 알려지고 있으며 이러한 비선형 관계를 효과적으로 예측하기 위해서 본 연구에서는 비선형 예측모형을 개발 하고자 한다. 최근 비선형 예측모형에서 불확실성을 고려한 모형에 대한 연구가 활발히 진행되고 있으며 특히, 다중 모형을 사용한 Ensemble 개념의 예측모형 도입이 이루어지고 있다. 본 연구에서는 국내 다목적댐 유입량 및 강수량에 대해서 최적 기상변량을 도출하고 이를 활용한 비선형 Ensemble 예측모형을 개발하였다. 일반적인 선형 회귀분석 모형에 비해 기상현상과 수문현상에 비선형성을 효과적으로 재현할 수 있는 장점을 확인할 수 있었으며 이와 더불어 예측결과에 대한 불확실성을 제공함으로서 신뢰성 있는 수자원 계획을 위한 기초자료로서 활용이 가능할 것으로 판단된다.

• Korean Institute of Interior Design Journal
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• v.22 no.5
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• pp.207-215
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• 2013

Due to an increase in the number of large-scale and high rise buildings, the importance of indoor location information has been highlighted. As a result, seamless three-dimensional space information, linked to various indoor and outdoor services is required. The purpose of this study is to develop a system which can edit and operate indoor space information using the IndoorGML(Geography Markup Language). It provides functions such as converting and editing authoring indoor space using the IndoorGML. Based on defined schema which is the IndoorGML international standardization work, we develop the "Editor" and "Viewer" for the IndoorGML. When indoor space is modeled in an authoring tool, a variety of topologies can be created automatically. These are available to be edited and modified. Moreover, the file of model can be saved as IndoorGML, SBM and KML file. These files are viewed by the "Viewer". Indoor LBS(Location Based Service)is served with these principles.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.60-70
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• 2014

This paper discusses the impacts of large scale grid-connected wind farm equipped with permanent magnet synchronous generator (PMSG) on power system small signal stability (SSS) incorporating wind generation uncertainty and volatility. Firstly, a practical simplified PMSG model with rotor-flux-oriented control strategy applied is derived. In modeling PMSG generator side converter, the generator-voltage-oriented control strategy is utilized to implement the decoupled control of active and reactive power output. In modeling PMSG grid side converter, the grid-voltage-oriented control strategy is applied to realize the control of DC link voltage and the reactive power regulation. Based on the Weibull distribution of wind speed, the Monte Carlo simulation technique based is carried out on the IEEE 16-generator-68-bus test system as benchmark to study the impacts of wind generation uncertainty and volatility on small signal stability. Finally, some preliminary conclusions and comments are given.