• Journal of Korean Academy of Fundamentals of Nursing
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• v.23 no.4
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• pp.448-459
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• 2016

Purpose: This ethnographic study was conducted to explore and understand the meaning of the daily life of nurses in emergency departments. Objectives for this study were to identify and describe the true nature of emergency room nurses' daily experience and create a theoretical model based on the findings. Methods: Data were collected through in-depth interviews and participants observation. These data were recorded and transcribed verbatim with consent of the informants, 10 nurses who had cared for patients in emergency rooms. Data were collected between November 2013 and October 2014. Interviews continued until no new information could be identified from transcripts. Data were analyzed using the taxonomic analysis method developed by Spradley. Results: Based on the data acquired from interviews, nurses' cultural domains were classified as 'extensity of emergency room nurses', 'temporality of emergency room nurses', 'relationships among emergency room nurses' and 'becoming an emergency room nurses'. Conclusion: The daily culture of emergency room nurses could be summarized as 'busy daily life amidst confusion'. However, many nurses boosted their self-esteem by taking care of patients' collaboration with fellow nurses. In other words, nurses in emergency room forms a dynamic culture and pursue professionalism, rather than a simple chaotic daily life culture.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1274-1285
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• 2015

This paper deals with model reference adaptive system (MRAS) speed estimators based on a secondary flux for linear induction motors (LIMs). The operation of these estimators significantly depends on an adaptation mechanism. Fixed-gain PI controller is the most common adaptation mechanism that may fail to estimate the speed correctly in different conditions, such as variation in machine parameters and noisy environment. Two adaptation mechanisms are proposed to improve LIM drive system performance, particularly at very low speed. The first adaptation mechanism is based on fuzzy theory, and the second is obtained from an LIM mechanical model. Compared with a conventional PI controller, the proposed adaptation mechanisms have low sensitivity to both variations of machine parameters and noise. The optimum parameters of adaptation mechanisms are tuned using an offline method through chaotic optimization algorithm (COA) because no design criterion is given to provide these values. The efficiency of MRAS speed estimator is validated by both numerical simulation and real-time hardware-in-the-loop (HIL) implementations. Results indicate that the proposed adaptation mechanisms improve performance of MRAS speed estimator.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.7
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• pp.919-927
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• 1997

The main purpose of this study is to determine bifurcation as the primary instability of a glass melting furnace. Steady-state and unsteady characteristics of natural convection in the partially open cavity as appeared in a glass melting furnace is investigated by using numerical analysis. Three types of convection, such as steady laminar, unsteady periodic or unsteady quasi-periodic convection may occur according to the temperature difference between upper two isothermal surfaces along the depth of cavity in a glass melting furnace. In the temperature difference of 150-900 K between batch and free surface, the larger the temperature difference, the weaker the convection strength and unsteadiness. Since the glass viscosity is increasing exponentially in the lower temperature, the batch freezes the thermofluidic field especially below the surface of it. If the depth of cavity is 0.5 m, the bifurcation to time-dependent natural convection may occur in the range of 60-650 K. If that is 1.0 m, it may occur in the whole range of temperature difference.

• Journal of computational fluids engineering
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• v.8 no.2
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• pp.16-23
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• 2003

A numerical study of the mixing of two fluids(pure water and a solution of glycerol in water) in a microchannel was carried out. By varying the glycerol content of the glycerol/water solution, the variation in mixing behavior with changes in the difference of the properties of the two fluids(e.g., viscosity, density, diffusivity) was investigated. The mixing phenomena were tested for three micromixers: a square mixer, a three-dimensional serpentine mixer, and a staggered herringbone mixer. The governing equations of continuity, momentum and solute mass fraction were solved numerically. To evaluate mixing performance, a criterion index of mixing of mixing uniformity was proposed. In the systems considered, the Reynolds numbers based on averaged properties were 1 and 10. For low Reynolds number (Re = 1), the mixing performance varied inversely with mass fraction of glycerol due to the dominance of molecular diffusion. The mixing performance by diffusion deteriorated due to a significant reduction in the residence time of the fluid inside the mixers.

• Korean Journal of Child Studies
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• v.16 no.1
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• pp.21-31
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• 1995

This documentary study investigated the background, content and methods of the filial education of children in the Choson Dynasty; that is, the ways in which filial conduct was taught so that the child learned manners and learned to assist parents in everyday life. The subjects of this study were the upper class(sonbi) and ranged from 7 or 8 to 13 or 14 years in Korean age. The Confucian view of nature, ethics and the family system emphasized filial duty during the Choson Dynasty. The contents of filial education were the fundamentals of filial conduct, such as daily greetings, participation(in family events), and an affectionate and respectful attitude towards parent. The method for filial education was that parents and instructors were to be good model in everyday life so that children got accustomed to good conduct. It is difficult to apply the filial conduct of the Choson Dynasty to today's life, but its basic spirit, that is, loving and respecting human beings, is still invaluable for modern times. This spirit may be applied to childhood education today by amending some out-of-date contents, and the filial ethos universalized in daily life could become a prescription for today's chaotic society.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.4
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• pp.293-301
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• 2001

This paper reviews three methods to compute a pointwise confidence interval of neuro-fuzzy models and compares their estimation perfonnanee through simulations. The eOITl.putation methods under consideration include stacked generalization using cross-validation, predictive error bar in regressive models, and local reliability measure for the networks employing a local representation scheme. These methods implemented on the neuro-fuzzy models are applied to the problems of simple function approximation and chaotic time series prediction. The results of reliability estimation are compared both quantitatively and qualitatively.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.2
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• pp.113-121
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• 2000

This paper presents a parallel-structure fuzzy system(PSFS) for prediction of time series data. The PSFS consists of a multiple number of fuzzy systems connected in parallel. Each component fuzzy system in the PSFS predicts the same future data independently based on its past time series data with different embedding dimension and time delay. The component fuzzy systems are characterized by multiple-input singleoutput( MIS0) Sugeno-type fuzzy rules modeled by clustering input-output product space data. The optimal embedding dimension for each component fuzzy system is chosen to have superior prediction performance for a given value of time delay. The PSFS determines the final prediction result by averaging the outputs of all the component fuzzy systems excluding the predicted data with the minimum and the maximum values in order to reduce error accumulation effect.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.1
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• pp.53-59
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• 2010

In this paper, we propose a novel chaotic micromixer of which mixing mechanism is based upon magnetohydrodynamic (MHD) multi-vortical flow generation in a simple straight microchannel. In the microchannel of the micromixer has electrodes patterned on two side walls and bottom wall. Lorentz forces are variously induced by changing applied voltages at the patterned electrodes in order to pump and mix conductive fluids in the microchannel. Three-dimensional computational fluid dynamics simulations were conduced to characterize mixing behaviors inside the MHD micromixer. The mixing efficiencies were also evaluated for the various flow conditions.

• The Journal of Korean Medical History
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• v.27 no.2
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• pp.63-74
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• 2014

The purpose of this study is to investigate the organization and contents of "CheongKangEuiGam" and raise interests in study on Oriental Medicine in the 20th century. Songjae, LeeJongHyeong was a disciple of Cheongkang and published this book in 1984 by organizing the medical theory of Cheongkang, KimYoungHoon who lived in the turbulent period from the late period of Joseon to a chaotic state of Korea after the independence of Korea. Even though it is relatively recently published, it is a very important clinical book as well as historical material to look at the aspects of Oriental Medicine in the 20th century. The book contains several notable medical thoughts. First, you can look at one perspective of the 20th century Oriental Western medical study which is initiated by the introduction of Western Medicine in classification schemes and description of disease symptoms. In addition, he uses medicinal herbs such as Cyperus rotundus L., Pinellia ternate(Thunb.) Breit., Poria cocos Wolf, Angelica gigas Nakai, Cnidium officinale, and Paeonia lactiflora Pall as important items, it is found that qi and blood depressed gallbladder is considered as the main pathology of the disease. In terms of names and meaning of prescriptions, he prefers to use mild medicinal herbs rather than intense medicinal herbs. It seems that he tries to help people's lives with cheap and effective medicinal herbs.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.10
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• pp.130-136
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• 2008

The purpose of this study was to investigate chaotic characteristics of major joint motions during treadmill walking. Gait experiments were carried out for 20 healthy young women. The subjects were asked to walk on a treadmill at their own natural speeds. The chaos analysis was used to quantify nonlinear motions of eleven major joints of each woman. The joints analyzed included the neck and the right and left shoulders, elbows, hips, knees and ankles. The recorded gait patterns were digitized and then coordinated by motion analysis software. Lyapunov exponent for every joint was calculated to evaluate joint characteristics from a state space created by time series and its embedding dimension. This study shows that differences in joint motion were statistically significant.