• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.357-360
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• 2005

In the synthesis of the continuously distributed line source antennas with arbitrary patterns, the formulas of Taylor sum pattern and Bayliss difference pattern have been mainly used. In this paper, an optimization scheme is newly presented to directly synthesize the desired difference patterns from Taylor line source formula, and then the distributions are numerically adapted to the specified difference patterns by using an appropriate iterative sampling method.

• Communications for Statistical Applications and Methods
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• v.26 no.6
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• pp.539-556
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• 2019

This paper derive a method to solve change point regression problems via a process for obtaining consequential results using properties of a difference-based intercept estimator first introduced by Park and Kim (Communications in Statistics - Theory Methods, 2019) for outlier detection in multiple linear regression models. We describe the statistical properties of the difference-based regression model in a piecewise simple linear regression model and then propose an efficient algorithm for change point detection. We illustrate the merits of our proposed method in the light of comparison with several existing methods under simulation studies and real data analysis. This methodology is quite valuable, "no matter what regression lines" and "no matter what the number of change points".

• The Journal of Fisheries Business Administration
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• v.48 no.4
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• pp.11-25
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• 2017

The purpose of the study is to analyze the status and trend of less favored condition of fishing village in Korean island regions using the census of agriculture, forestry and fisheries. The less favored condition was measured as the difference in accessibility to major services and in fishery sales and resident infrastructure, applying the difference-in-difference method and propensity score matching method respectively. The result shows that access to major services has improved in island area between 2010 and 2015, implying that related policies such as the island comprehensive development project have been successful to some extent. However, some educational facilities, cultural facilities, and health facilities still have low inaccessibility and fishery sales are also significantly lower than in general area. This suggests that it is necessary to maintain related policies like the direct payment of fisheries.

• Communications of the Korean Mathematical Society
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• v.14 no.4
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• pp.815-832
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• 1999

High-order weighted difference schemes with uniform meshes are considered for the convection-diffusion problem depending on Reynolds numbers. For small Reynolds numbers, a weighed cen-tral difference scheme is suggested since there is no boundary layer. For large Reynolds numbers, we propose a modified up wind method with an artificial diffusion in order to overcome nonphysical oscilla-tion of central schemes and obtain good accuracy in the boundary later. Existence and corresponding error estimates of the solution for the difference scheme have been shown. Numerical experiments are provided to back up the analysis.

• The KIPS Transactions:PartB
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• v.12B no.3 s.99
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• pp.301-312
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• 2005

Three different cases should be considered for motion tracking: moving object with fixed camera, fixed object with moving camera and moving object with moving camera. Two methods are widely used for motion tracking: the optical flow method and the difference frame method. The optical new method is mainly used when either one, object or camera is fixed. This method tracks object using time-space vector which compares object position frame by frame. This method requires heavy computation, and is not suitable for real-time monitoring system such as DVR(Digital Video Recorder). The different frame method is used for moving object with fixed camera. This method tracks object by comparing the difference between background images. This method is good for real-time applications because computation is small. However, it is not applicable if the camera is moving. This thesis proposes and implements the motion tracking system using the difference frame method with PTZ(Pan-Tilt-Zoom) control. This system can be used for moving object with moving camera. Since the difference frame method is used, the system is suitable for real-time applications such as DVR.

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.421-427
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• 2010

The purpose of this study was to investigate the relationship between the quantitative analysis of biomechanical movement and the qualitative analysis of video software in order to evaluate for the walking movement. The fourteen collegiate students who agreed with the purpose and method of this study participated as subjects. The slow walking and fast walking of the subjects in the place of experiment were photographed, and calculated several mechanical factors. This empirical evidence from the experiment indicated the significant difference(p<.001) between each distant factors of the walking movement for both analyses methods, but there was no statistically significant difference between the spacial factors observed in the experiment. For more detail, no significant difference between the walking ratios that expressed the coordination between stride length and stride frequency was found. The findings also indicated the high coefficient of correlation(over r=.9) which supports higher explanation force for the biomechanical method and the Dartfish video software method. Therefore, if the data was gathered by using the proper experimental method, the video software method could be used just like the quantitative data of biomechanical method.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.4
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• pp.569-579
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• 2013

A steel-type breakwater that uses a submerged dual horizontal porous plate was originally proposed by Kweon et al. (2005), and its hydrodynamic characteristics and design methodology were investigated in a series of subsequent researches. In particular, Kweon et al. (2011) proposed a method of estimating the vertical uplift force that acts on the horizontal plate, applicable to the design of the pile uplift drag force. However, the difference between the method proposed by Kweon et al. (2011), and the wave force measured at a different time without a phase difference, have not yet been clearly analyzed. In this study, such difference according to the method of estimating the wave force was analyzed, by measuring the wave pressure acting on a breakwater model. The hydraulic model test was conducted in a two-dimensional wave flume of 60.0 m length, 1.5 m height and 1.0 m width. The steepness range of the selected waves is 0.01~0.03, with regular and random signals. 20 pressure gauges were used for the measurement. The analysis results showed that the wave force estimate in the method of Kweon et al. (2011) was smaller than the wave force calculated from the maximum pressure at individual points, under a random wave action. Meanwhile, the method of Goda (1974) that was applied to the horizontal plate produced a smaller wave force, than the method of Kweon et al. (2011). The method of Kweon (2011) was already verified in the real sea test of Kweon et al. (2012), where the safety factor of the pile uplift force was found to be greater than 2.0. Based on these results, it was concluded that the method of estimating the wave force by Kweon et al. (2011) can be satisfactorily used for estimating the uplift force of a pile.

• The Journal of Korean Academic Society of Nursing Education
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• v.5 no.1
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• pp.86-96
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• 1999

Effectiveness of the videotaped-record learning method in teaching intramuscular injection skill was investigated using an experimental research methodology. Data was collected from 57 female students attending Fundamental nursing class from two depts. of nursing in Chung-ju and Seoul. The subjects were assigned to two groups, the experimental group of 30 and the control group of 27. The independent variable was videotaped-record learning method and the dependent variable were the degree of knowledge achivement, nursing skill achivement, competence on practicing intramuscular injection skill and satisfaction about the learning method. Data was analyzed using descriptive statistics, chi-square test, t-test and Pearson's correlation coefficient with SPSS-PC program. The results were summarized as follows ; 1. There was statistically significant difference between the experimental group and control group in knowledge achievement about intramuscular injections (t=4.721, P=.000). 2. There was statistically significant difference between the experimental group and control group in nursing skill achievement(t=3.542, P=.001). 3. There was no statistically significant difference between the experimental group and control group in competence on practicing intramuscular injection skill (t=.627, P=.533). 4. There was statistically significant difference between the experimental group and control group in satisfaction about learning method(t=4.708, P=.000). 5. There was significant correlation between nursing skill achievement and knowledge achievement(r=.233, p<.05). In conclusion, this study suggests that videotaped-record learning method is an effective learning method for achieving intramuscular injection skill as a basic nursing skills. Therefore, further study with more developed research design and other fundamental nursing skill practice will be needed to investigate the effectiveness of videotaped-recored learning method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.37-39
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• 2010

In this study, with new office construction site of S Construction company as subject, to solve all the problems according to reduced hydration heat and temperature crack of mass concrete used mat foundation and placing time difference, low heat combination of coarse particle cement and fly-ash and setting time difference applied AE water reducing agent, and to prevent the early frost damage caused by low outdoor temperature, a heat insulation method using double bubble sheet was conducted. As a result, it was found that hydration heat and setting time difference was reduced by applying a low heat combination and setting time difference construction method, and that the high insulation capability of the double bubble sheet was able to not only prevent the early frost damage but also reduce temperature difference between the central part and the upper part of mass concrete.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.2
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• pp.191-205
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• 1993

In order to compare the strength of soldered joints relative to the various sol dering method, soldering processes were performed using Palladium based ceramo-metal alloy(Bond-on 4)and Nickel-cromium alloy(Vera Bond). The obtained data include difference in strength between presoldering and postsoldering The data also contain difference among postsoldered groups for 3 difference soldering methods(torch, infrared. Oven) The following results were obtained : 1. For postsoldering with Pd alloy, the oven-using group showed the highest strength while the difference in strength between the torch-using group and the infrared machine group was negligible. 2. For Pd alloy with the torch method, postsoldering resulted in the higher strength than presoldering. 3. There was a negligible difference in strength between presoldering and postsoldering when Ni-Cr alloy with torch method is used. 4. Through microscopic study of the fractured surfaces, the torch-using group showed more porosity than both the oven-using and the infrared machine groups. 5. In terms of fracturing patterns, the oven-using group showed adhesive failure while both the torch and the infrared machine groups showed cohesive failure and cohesive-adhesive failure.