• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.2
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• pp.206-211
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• 2009

This paper presents a methodology to 1-day-forecast stock index using the automatic feature extraction method based on the neural network with weighted fuzzy membership functions (NEWFM). The distributed non-overlap area measurement method selects the minimized number of input features by automatically removing the worst input features one by one. CPP$_{n,m}$(Current Price Position of the day n: a percentage of the difference between the price of the day n and the moving average from the day n-1 to the day n-m) and the 2 wavelet transformed coefficients from the recent 32 days of CPP$_{n,m}$ are selected as minimized features using bounded sum of weighted fuzzy membership functions (BSWFMs). For the data sets, from 1989 to 1998, the proposed method shows that the forecast rate is 60.93%.

• Journal of Korean Physical Therapy Science
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• v.23 no.1
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• pp.1-8
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• 2016

Purpose : The purpose of this study was to investigate the response of pulmonary function and heart rate recovery of smoker and nonsmoker in males aged 20s after graded maximal exercise. Method : The subjects were composed of smoker group (n=12) and nonsmoker group (n=12) in males aged 20s. Each groups completed an graded maximal exercise with Bruce protocol and were assessed on the pulmonary function(forced vital capacity : FVC, forced expiratory volume-one second : FEV1, FEV1/FVC) and heart rate. Result : The results were as follows: First, heart rate in the measurement point was a statistically significant difference for smoker and non-smoker group after maximal exercise, but FVC, FEV1, FEV1/FVC was no difference. Second, FEV1/FVC between smoker and nonsmoker group was a statistically significant difference after maximal exercise, but FVC, FEV1, heart rate was no difference. Conclusion : The results of this study is that smoking is negative effects on FEV1/FVC of pulmonary function in males aged 20s after maximal exercise.

• The Journal of Korean Physical Therapy
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• v.32 no.2
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• pp.70-74
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• 2020

Purpose: This study examined whether 1) the motor inhibition response as cognitive-behavioral component is learning though a stop signal task using stop-signal paradigm, and 2) whether there is a difference in the learning degree according to imagery training and actual practice training. Methods: Twenty young adults (males: 9, females: 11) volunteered to participate in this study, and were divided randomly into motor imagery training (IT, n=10) and practice training (PT, n=10) groups. The PT group performed an actual practice stop-signal task, while the IT group performed imagery training, which showed a stop-signal task on a monitor of a personal computer. The non-signal reaction time and stop-signal reaction time of both groups were assessed during the stop-signal task. Results: In the non-signal reaction time, there were no significant intra-group and inter-group differences between pre- and post-intervention in both groups (p>0.05). The stop-signal reaction time showed a significant difference in the PT group in the intra-group analysis (p<0.05). On the other hand, there was no significant intra-group difference in the IT group and inter-group difference between pre- and post-intervention (p>0.05). Conclusion: These results showed that the motor inhibition response could be learned through a stop-signal task. Moreover, these findings suggest that actual practice is a more effective method for learning the motor inhibition response.

• Journal of Korean Academy of Nursing Administration
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• v.10 no.2
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• pp.211-218
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• 2004

Purpose: The purpose of this study was to examine the core competency and career commitment of the preceptors to identify utility of the preceptorship as career management program. Method: The subjects were 107 clinical nurses who were working in one university hospital composed of the head nurses(n=27), non-preceptors(n=28), new graduate nurses(n=26) and preceptors(n=26). Demographic characteristics, core competency and career commitment were measured. The core competency was evaluated by the head nurses, non-preceptors, new graduate nurses, and preceptor themselves. And the career commitment was compared between the preceptors and non-preceptors. For data analyses, percentage, mean, t-test, ANOVA were adopted with the use of SPSS WIN 10.0. Result: The results of this study showed that the core competency of the preceptors was evaluated excellently by all subjects. In three domains, there were no significant difference in role model, socialization facillitator and educator except for learning experience planning between the head nurses, non-preceptors, new graduate nurses and preceptors. The career commitment was significant difference between the preceptors and non-preceptors. Conclusions: The finding above indicated that the preceptorship utilized the improvement of the core competency and career commitment of the preceptors as career management program. therefore, continually, the effort and interest for development of the preceptorship can be a remarkable contribution for nurses' career management in nursing organization.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.9
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• pp.781-786
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• 2005

The binding energy in the n-type $GaAs/Al_xGa_{1-x}As$ quantum well is calculated. The shooting method, modified from the finite difference method, is used for the calculation of the subband energy level and its wave function. In order to account tot the change of the potential energy due to the charged particles, impurities and electrons, the self consistent method is employed. The wave function used for the calculation of the binding energy is assumed to be composed of the envelope function and hydrogenic 1s function. Then, the binding energies calculated by taking into account lot two different types of the hydrogenic 1s function are compared.

• Bulletin of the Korean Mathematical Society
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• v.54 no.3
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• pp.1069-1080
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• 2017

The Tribonacci sequence ${\{T_n}\}_{n{\geq}0}$ resembles the Fibonacci sequence in that it starts with the values 0, 1, 1, and each term afterwards is the sum of the preceding three terms. In this paper, we find all integers c having at least two representations as a difference between a Tribonacci number and a power of 2. This paper continues the previous work [5].

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.19-35
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• 2004

We develop in this paper some preconditioners for sparse non-symmetric M-matrices, which combine a recursive two-level block I LU factorization with multigrid method, we compare these preconditioners on matrices arising from discretized convection-diffusion equations using up-wind finite difference schemes and multigrid orderings, some comparison theorems and experiment results are demonstrated.

• Steel and Composite Structures
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• v.12 no.3
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• pp.249-260
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• 2012

In this study, stress and deflection behaviours of T-type welding joint applied to HE200M steel beam and column were investigated in finite element method (FEM) under different distributed loads. In the 3D-FEM modelling, glue option was used to contact between steel materials and weld nuggets. Geometrical model was designed as 3-dimensional solid in ANSYS software program. After that, homogeneous, linear and isotropic properties were used to design to materials of model. Solid-92 having 3-dimensional, 4 faced and 10-noded was selected as element type. In consequence of mesh operation, elements of 13285 and nodes of 28086 were occurred. Load distribution was applied to top surface of steel beam to determine behaviours of stress and deflection. As a result of FEM analysis applied with the loads of 55,000 N, 110,000 N and 220,000 N, maximum values were obtained as 116 N/$mm^2$, 232 N/$mm^2$ and 465 N/$mm^2$ for stress and obtainedas 1,083 mm, 2,166 mm and 4.332 mm for deflection, respectively. When modelling results and classical calculation values were compared, it was obtained difference of 10 % for stress values and 2.5% for deflection values.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.103-108
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• 2003

In this paper, the current lead for superconducting device is studied by numerical method. The current lead is cooled by surrounded $N_{2}$ gas by natural convection. The heat conduction equation for current lead and boundary layer equation for $N_{2}$ gas must be solved simultaneously. The boundary layer equation for $N_{2}$ gas is highly nonlinear for varied temperature of current lead. So the linearization method is adopted for simplicity. Numerical results using natural convection cooling are compared with the conventional cooling methods such as conduction cooling and vapor cooling methods. The main difference of natural convection cooing is the non-zero temperature gradient at the top of current lead for the minimum heat dissipation into superconducting devices. For the optimized conduction-cooling and vapor-cooling current leads, the temperature gradient at the top of current lead is zero. Also, the heat flow at the cold end is much smaller than conduction cooling case.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1995.06a
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• pp.143-148
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• 1995

In this paper, we describe a fast 3D video segmentation method using mathematical morphology. The proposed 3D video segmentation algorithm is composed of intra-frame segmentation step and inter-frame segmentation step. In the intra-frame segmentation step, the first frame is segmented using the fast hierarchical segmentation method. Then, in the inter-frame segmentation step, the next frames are segmented using markers that are extracted from the difference of previous segmentation result and simplified present image. Experimental results show that the proposed method has more fast structure and is suitable for video segmentation.