• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.393-396
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• 2010

A secure and novel watermarking system based on complemented Maximum Length Cellular Automata (MLCA) and Two-Dimension Cellular Automata Transform (2D CAT) is proposed. In this watermarking scheme, the original watermark which is first encrypted by complemented MLCA with the private keys, and the encrypted watermark is embedded into the CAT domain of the cover image. Experiment results show that this new method is more secure and provides robust performance against watermarking attacks.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.531-540
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• 2008

An Adaptive Random Testing(ART) is one of test case generation algorithms, which was designed to get better performance in terms of fault-detection capability than that of Random Testing(RT) algorithm by locating test cases in evenly spreaded area. Two ART algorithms, such as Distance-based ART(D-ART) and Restricted Random Testing(RRT), had been indicated that they have significant drawbacks in computations, i.e., consuming quadratic order of runtime. To reduce the amount of computations of D-ART and RRT, iterative partitioning of input domain strategy was proposed. They achieved, to some extent, the moderate computation cost with relatively high performance of fault detection. Those algorithms, however, have yet the patterns of non-uniform distribution in test cases, which obstructs the scalability. In this paper we analyze the distribution of test cases in an iterative partitioning strategy, and propose a new method of input domain enlargement which makes the test cases get much evenly distributed. The simulation results show that the proposed one has about 3 percent of improvement in terms of mean relative F-measure for 2-dimension input domain, and shows 10 percent improvement for 3-dimension space.

• Phonetics and Speech Sciences
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• v.9 no.3
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• pp.33-40
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• 2017

This study aimed to examine how Korean-English bilinguals make use of VOT and F0 cues in perception and production of Korean (lenis vs. aspirated) and English (voiced vs. voiceless) stops. It was explored whether bilinguals with extensive experience living in the U.S. exhibit native-like or interactive patterns in the cue use for both languages. Participants produced monosyllabic word-initial stops within a carrier sentence in each language, and performed forced-choice identification tasks with synthesized stimuli varying in 7 VOT steps and 7 F0 steps with base tokens of /$t^han$/ for Korean and /$t{\ae}n$/ for English. Listeners were required to select either /tan/ or /$t^han$/ for Korean and either /$d{\ae}n$/ or /$t{\ae}n$/ for English. The results from binary logistic regression analyses for each listener indicated that all bilinguals placed greater weight on F0 than VOT when distinguishing between the Korean lenis and aspirated stops, and greater weight on VOT than F0 in distinguishing between the English voiced and voiceless stops. In terms of production, all participants showed remarkably overlapping ranges in the VOT dimension and separating ranges in the F0 dimension for the stop contrast of Korean, while forming overlapping ranges in the F0 dimension and separating ranges in the VOT dimension for the stop contrast of English. These results indicate that the bilinguals with extensive exposure to L2 manage the stop systems of the two languages independently, both in perception and production, employing the opposite cue use for stops in the two languages. It was also found that the absolute beta-coefficient values of the perceptual cues for Korean stops were generally smaller than those for English and those reported in a previous study as for later bilinguals, which may have resulted from Korean not being their dominant language.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.480-487
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• 2015

The purpose of this study was to examine the association between oral health status and health related quality of life (HRQoL). The study used a nationally representative sample of Koreans (2013 Korea National Health and Nutrition Examination Survey) aged 19~64 years (n=3,252). Dependent variable was HRQoL, which was assessed with each component of EuroQol-5 dimension (EQ5D). Independent variable was oral health status (oral pain, chewing problem, speaking problem, and perceived oral health). After adjustment for confounders (socio-demographic factors, oral health behaviors, health behaviors, and physical conditions), the risk of having poor HRQoL was greater in adults with poor oral health status. The odds ratio (OR) of having pain/discomfort were 1.50 (95% confidence interval [CI], 1.22~1.86) for respondents with oral pain, 1.72 (95% CI, 1.33~ 2.22) for respondents with chewing problem, 1.79 (95% CI, 1.22~2.62) for respondents with speaking problem, and 1.36 (95% CI, 1.09~1.70) for respondents with poor perceived oral health. The OR of having anxiety/depression were 1.74 (95% CI, 1.28~2.38) when having a chewing problem, 1.72 (95% CI, 1.12~2.64) when having a speaking problem, and 1.54 (95% CI, 1.14~2.08) when rating his/her oral health poor. Among Korean adults, two of the EQ5D components were associated with oral health status. Future study is needed to examine the detailed causal relations between oral health status and HRQoL longitudinally.

• Journal of the Korean Magnetic Resonance Society
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• v.10 no.1
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• pp.59-73
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• 2006

Spin-lattice relaxation pathway of $CH_2$ spin system by two dimensional NOESY sequence has been discussed. Two-dimensional spectra governed by dipolar relaxation mechanism were simulated in term of transfer mode, the generalization of conventionally used magnetization mode in one dimension. The transfer matrix directly related to the Redfield relaxation matrix can be constructed by the multiplet of transfer mode. The observable relaxation transfer modes causes to variation of the off-diagonal signal intensity of phase sensitive NOESY spectra from which variable spectral density can be extracted with simple group theoretical calculation. The variation of the J-coupling peak intensity as a function of the mixing time in 2-D spectra for $n-Undecane-5-^{13}C$ and Bromoacetic $2-^{13}C$ acid has been theoretically traced.

• Physical Therapy Korea
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• v.27 no.3
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• pp.212-219
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• 2020

Background: Although the original version of the health-related quality of life (HRQOL) questionnaires are found to be acceptable, the cross-culturally adapted versions may not be comparable to their original version. Objects: To examine dimensionality and construct validity of two Korean versions of the brief version of the World Health Organization Quality of Life (WHOQOL-BREF) and EuroQOL-5 dimension (EQ-5D) questionnaires. Methods: A total of 77 cancer survivors undergoing palliative rehabilitation programs from two rehabilitation institutes was recruited from April 16, 2018 to June 26, 2019. The WHOQOL-BREF and the EQ-5D were filled out by the various cancer survivors following a particular session of rehabilitation programs. The scores were analyzed with Winsteps Rasch analysis computer program using the rating scale model. Rasch fit statistics were used to determine the dimensionality and the item difficulty calibrations of WHOQOL-BREF and EQ-5D. Results: All items except two, negative feeling, need treatment function and pain prevent activity (mean square [MnSq] = 2.42, 1.82 and 2.51, respectively), were found to be acceptable, while two items of the EQ-5D, anxiety/depression and self-care, were misfit (infit MnSq = 1.65 and 0.38, respectively). Item difficulty calibrations of WHOQOL-BREF match person ability measures (i.e., HRQOL) fairly well. However, the person ability distribution showed obvious ceiling effects for EQ-5D. All items of EQ-5D were appeared to be less challenged in comparison with those of WHOQOL-BREF. Conclusion: Item-level analysis using the Rasch model supports the quality of culturally adapted items used to measure the HRQOL one exception; that is, whether or not to include misfit items as part of the HRQOL measurements. Additionally, cancer survivors undergoing palliative rehabilitation programs appear to have more of a tendency to view the EQ-5D items as being more challenging than the WHOQOL-BREF.

• Solar Energy
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• v.11 no.2
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• pp.63-69
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• 1991

A Steady laminar natural convection heat transfer from two isothermal square beams attached to a vertical adiabatic plate has been studied numerically. The results have been obtained for dimensionless beam spacings, $0.5{\le}D/L{\le}3.0$, and for Gr=5000-10000 at ${\phi}_2/{\phi}_1=1.0$. 1. The local Nusselt number from the beam surface is increased with the dimension-less beam spacing D/L. but that of the downward surface of the lower beam is almost same as the D/L increases. And, the local Nusselt number from the upward surface of a lower beam is greatly increased with D/L. 2. The beam spacings of the maximum mean Nusselt number for the downward surface of an upper beam and the upward surface of a lower beam occur at. D/L =2.6 and 2.0 respectively. 3. The beam spacing for the maximum total mean Nusselt number occurs at D/L = 2.6.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.240-240
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• 2015

As Simpson et al. (1990) emphasized the importance of the straining process in the stratification and mixing in the estuarine circulation process, various researches have investigated on the relative contribution of each process to the overall potential energy anomaly dynamics. However, many numerical works have done only for two dimensional modeling along channel or the short distance cross sectional three dimensional simulations as Burchard et al. (2008) and the estuarine channel was not simulated so far. But, in the study on the physics of shallow coastal seas, spatial dimension in the three dimensional way affects significantly on results of a particular numerical model. Therefore, the comparison of two and three dimensional models is important to understand the real physics of mixing and stratification in an estuary. Also, as Geyer and MacCready (2013) pointed out that the lateral process seems to be important in determining the periodic stratifications, to study such process the three dimensional modeling must be required. The present study uses a numerical model to show the signification roles of each term of the time-dependent dynamic equation for the potential energy anomaly (PEA) in controlling along and lateral channel flows and different stratification structures. Moreover, we present the relationships between the ${\Phi}$-advection, the depth mean straining, vertical mixing and vertical advection can explain well how water level, salinity distribution and across velocity 2D model are slightly different from 3D.

• Korean Journal of Community Nutrition
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• v.20 no.6
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• pp.423-432
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• 2015

Objectives: In Korea, the percentage of elderly is increasing at an unprecedented rate, and is expected to account for 40% of the population by 2060. This massive demographic change stresses the importance of research on aging as it is necessary to improve the quality of life (QoL) of this population. This study aimed to examine the health-related quality of life (HRQoL) of the rural elderly and to clarify its association with the nutrient adequacy ratio (NAR). Methods: A cross-sectional study was performed in S-gun, Chonbuk, a critical agricultural area. The elderly people without abnormal physical functioning composed our study population and the data were collected by personal visits to 336 elderly people aged over 65 years (110 males and 226 females). Subjects were interviewed with questionnaires pertaining to general characteristics and EuroQol (EQ-5D). Nutrient intakes were assessed two days by 24-hours recall method. Subjects were defined as high QOL group if EQ-5D index with Nam's model was above the median. Results: Generally, EQ-5D index was lower in women than in man, and lower in older subjects than in younger subjects. The percentages of people below the median were 42% (low QoL group) and 58% (high QoL group) were found to be the above the median. The high QoL group had higher NAR, especially for vitamin C, vitamin B1, vitamin B2 and folate. All dimensions in the EQ-5D were affected by NAR of some nutrients and especially anxiety/depression dimension was significantly correlated with NAR of 5 nutrients (protein, calcium, iron, vitamin C and vitamin B1) and EQ-5D scores. Conclusions: HRQol was significantly reduced in elderly with increasing age and this was more pronounced in women than in man. The NAR of some nutrients were associated with the EQ-5D index, especially anxiety/depression dimension, among rural elderly.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3388-3400
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• 2023

Detailed analysis of the neutron pathway through matter inside the nuclear reactor core is exceedingly needed for safety and economic considerations. Due to the constant development of high-performance computing technologies, neutronics analysis using computer codes became more effective and efficient to perform sophisticated neutronics calculations. In this work, a commercial pressurized water reactor (PWR) presented by Virtual Environment for Reactor Applications (VERA) Core Physics Benchmark are modeled and simulated using a high-fidelity simulation of OpenMC code in terms of criticality and fuel pin power distribution. Various problems have been selected from VERA benchmark ranging from a simple two-dimension (2D) pin cell problem to a complex three dimension (3D) full core problem. The development of the code capabilities for reactor physics methods has been implemented to investigate the accuracy and performance of the OpenMC code against VERA SCALE codes. The results of OpenMC code exhibit excellent agreement with VERA results with maximum Root Mean Square Error (RMSE) values of less than 0.04% and 1.3% for the criticality eigenvalues and pin power distributions, respectively. This demonstrates the successful utilization of the OpenMC code as a simulation tool for a whole core analysis. Further works are undergoing on the accuracy of OpenMC simulations for the impact of different fuel types and burnup levels and the analysis of the transient behavior and coupled thermal hydraulic feedback.