• Journal of the Korea Convergence Society
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• v.10 no.5
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• pp.27-34
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• 2019

In this paper, we propose a method to remove the background area by analyzing the pattern of the character area. In the character detection result of the MSER(Maximally Stable External Regions) method which distinguishes a region having a constant contrast background regions were detected. To solve this problem, we use the MSER method in natural images, the background is removed by calculating the change rate by searching the character area and the background area which are not different from the areas where the contrast values are different from each other. However, in the background removed image, using the LBP(Local Binary Patterns) method, the area with uniform values in the image was determined to be a character area and character detection was performed. Experiments were carried out with simple images with backgrounds, images with frontal characters, and images with slanted images. The proposed method has a high detection rate of 1.73% compared with the conventional MSER and MSER + LBP method.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1334-1335
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• 2008

Although many studies have been carried out about binary gas mixtures with $SF_6$, few studies were presented about breakdown characteristics of $SF_6/CF_4$ mixtures. At present study the breakdown characteristics of $SF_6/CF_4$ mixtures in uniform and nonuniform field was performed. The experiments were carried out under AC voltages. The sphere-sphere electrode whose gap distance was 1 mm was used and the point-plane electrode whose gap distance was 3 mm was used in a test chamber. $SF_6/CF_4$ mixture contained 20% $SF_6$ and 80% $CF_4$ and the experimental gas pressure ranged from 0.1 to 0.5 MPa. The results show that addition of $SF_6/CF_4$ mixtures increase AC breakdown voltages. In uniform field the breakdown voltages of gas were linearly increased according to the pressure. However in nonuniform field the breakdown voltages of gas were increased nonlinearly.

• Korean Journal of Adult Nursing
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• v.26 no.2
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• pp.159-170
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• 2014

Purpose: This research investigated the degree and predictors of hot flashes and hypogonadism symptoms in patients with prostate cancer receiving hormone replacement therapy. Methods: The subjects were 111 patients with prostate cancer receiving hormone replacement therapy in two university hospitals located in D city. The measurement tools included Hot Flash Diary and AMS (Aging Male's Symptoms rating scales). The data were analyzed using t-test, ANOVA, and binary logistic regression analysis. Results: The percentage of patients who experienced hot flashes among the participants was 14.4%. The predictors for hot flashes were eating irregularly, having coffee frequently and the types of hormone. The average score of hypogonadism symptom was 2.16 out of five-point scale and the highest score of hypogonadism symptom was the sexual symptoms (2.77 out of five-point scale). The predictors for hypogonadism symptom were eating habits and years of having the illness. Conclusion: These findings provide the information that irregularly eating habit was an important factor in hot flashes and hypogonadism symptoms of the participants. Therefore the development of a nutritional education encouraging regular meals is necessary for the given population.

• Journal of the Korean Society for information Management
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• v.23 no.1 s.59
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• pp.243-259
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• 2006

This paper examines the values of various library functions according to users' points of view. To execute this study, the several 'circumstance', related variables and 'condition' variables that lead to factors or functions of academic libraries were measured. Analysis was carried out in three stages. In the first, factor analysis was used on the three multi variable dimensions to ensure that the groups of variables loaded significantly and uniquely on the respective dimensions. The second phase of analysis involved the use of binary logistic regression analysis to complete research models. In the third phase, t-test was used to identify significant differences in the independent variables for additional explanation of the models. Books, competition & effectiveness and fee verses free (fee-free hereafter) are the three main factors that distinguish not only the purpose of using an academic library but also the degree of influence on knowledge, information and library facilities for the users. In addition, the fee-free factor related to digital library facilities was also uncovered.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3C
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• pp.256-262
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• 2002

This paper presents a novel radix-4 modular multiplication algorithm based on the sign estimation technique (3). The sign estimation technique detects the sign of a number represented in the form of a carry-sum pair. It can be implemented with 5-bit carry look-ahead adder. The hardware speed of the cryptosystem is dependent on the performance modular multiplication of large numbers. Our algorithm requires only (n/2+3) clock cycle for n bit modulus in performing modular multiplication. Our algorithm out-performs existing algorithm in terms of required clock cycles by a half, It is efficient for modular exponentiation with large modulus used in RSA cryptosystem. Also, we use high-speed adder (7) instead of CPA (Carry Propagation Adder) for modular multiplication hardware performance in fecal stage of CSA (Carry Save Adder) output. We apply RL (Right-and-Left) binary method for modular exponentiation because the number of clock cycles required to complete the modular exponentiation takes n cycles. Thus, One 1024-bit RSA operation can be done after n(n/2+3) clock cycles.

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.58-66
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• 2021

Spiral-wound woven wire meshes packed bed rotating cylinder electrode was used for the simultaneous removal of cadmium (Cd) and copper (Cu) from a binary solution. The effects of weight percent of each metal on the removal and current efficiencies were studied at an operating current of 345A, while the effect of current on the removal efficiency of both metals was investigated at three levels of current (240, 345.and 400 mA). The experiments were carried out at constant rotation speed 800 rpm, pH = 3, and a total concentration of metals (500 ppm). The results showed that the removal efficiency of copper increased from 89% to 99.4% as its weight percent increased from 20% to100%. In a similar fashion, the removal efficiency of cadmium increased from 81% to 97% as its weight percent increased from 20% to100%. The results confirmed that the removal efficiency of any metals declined in the presence of the other. Increasing of current resulted in increasing the removal efficiency of both metals at different weight percents. The results confirmed that current efficiencies for removing of copper and cadmium simultaneously decline with increasing of electrolysis time and weight percent of cadmium or with decreasing the weight percent of copper. Current efficiency was higher at the initial stage of electrolysis for all weight percents of metals. The results showed that the decay of copper concentration was exponential at all weight percents of copper, confirming that the electrodeposition of copper is under mass transfer control in the presence of cadmium. While the decay of cadmium concentration was linear at lower weight percent of cadmium then changed to an exponential behavior at high weight percent of cadmium in the presence of copper.

• Communications for Statistical Applications and Methods
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• v.29 no.5
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• pp.499-512
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• 2022

Intervention measures have been implemented worldwide to reduce the spread of the COVID-19 outbreak. The COVID-19 outbreak has occured in several waves of infection, so this paper is divided into three groups, namely those countries who have passed the pandemic period, those countries who are still experiencing a single-wave pandemic, and those countries who are experiencing a multi-wave pandemic. The purpose of this study is to develop a multi-wave Richards model with several changepoint detection methods so as to obtain more accurate prediction results, especially for the multi-wave case. We investigated epidemiological trends in different countries from January 2020 to October 2021 to determine the temporal changes during the epidemic with respect to the intervention strategy used. In this article, we adjust the daily cumulative epidemiological data for COVID-19 using the logistic growth model and the multi-wave Richards curve development model. The changepoint detection methods used include the interpolation method, the Pruned Exact Linear Time (PELT) method, and the Binary Segmentation (BS) method. The results of the analysis using 9 countries show that the Richards model development can be used to analyze multi-wave data using changepoint detection so that the initial data used for prediction on the last wave can be determined precisely. The changepoint used is the coincident changepoint generated by the PELT and BS methods. The interpolation method is only used to find out how many pandemic waves have occurred in given a country. Several waves have been identified and can better describe the data. Our results can find the peak of the pandemic and when it will end in each country, both for a single-wave pandemic and a multi-wave pandemic.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1520-1523
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• 1997

A rigorous dynamic simulation was performed in binary gas mixture H$_{2}$/CO (70:30 vol.%) to determinate start-up operating conditions of PSA(Pressure Swing Adsorption) processes. The rigorous dynamic model for the PSA process contains an Ergun equation for expressing the pressure drop in a bed, and valve equations to compute the boundary pressure change of the bed. As the result of the continuous dynamic simulation of 100 operating cyles in various initial conditions, the unsteady-state appeared in the early period and the cyclic steady-state came out about 20th cycle in feed condition and vaccum condition, and 30th cycle in pure H$_{2}$ condition. As time goes by valve equations made change the pressure at each end of the bed in ressurization, countercurrunt-depressurization and pressure equalization steps. The H$_{2}$ purity and the recovery is 99.99% and 86.73% respectively, which is slightly higher than the experimental data. Main contributiion of this study includes supplying fundamental technologies of handling combined variables PSA processes by developing rigorous models.

• Interaction and multiscale mechanics
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• v.6 no.1
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• pp.15-29
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• 2013

Phononic system composed of periodical elastic structures exhibit band gap phenomenon, and all elastic wave cannot propagate within the band gap. In this article, we consider one-dimensional binary materials which are periodically arranged as a 20-layered medium instead of infinite layered system for phononic system. The layered medium with finite dimension is subjected to a uniformly distributed sinusoidal loading at the upper surface, and the bottom surface is assumed to be traction free. The transient wave propagation in the 20-layered medium is analyzed by Laplace transform technique. The analytical solutions are presented in the transform domain and the numerical Laplace inversion (Durbin's formula) is performed to obtain the transient response in time domain. The numerical results show that when a sinusoidal loading with a specific frequency within band gap is applied, stress response will be significantly decayed if the receiver is away from the source. However, when a sinusoidal force with frequency is out of band gap, the attenuation of the stress response is not obvious as that in the band gap.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.201-205
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• 1989

In this study, the vertical type LPE system has been developed by fully hand-made. The temperature fluctuation and minimum cooling rate of this LPE system are within $\pm$0.05$^{\circ}C$ and 0.15$^{\circ}C$/min, respectively. It is considered that these properties are enough to grow III-V semiconductor compounds single crystals by liquid phase epitaxy method. Futhermore in this study. 1.3${\mu}{\textrm}{m}$ GaInAsP/InP single crystal growing has been carried out by this system. It has been obtained that the growing rate was about 0.72${\mu}{\textrm}{m}$/min for InP binary layer and 0.36${\mu}{\textrm}{m}$/min for GaInAsP quarternary layer under 0.6$^{\circ}C$/min cooling rate condition.