• Transactions on Electrical and Electronic Materials
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• v.15 no.5
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• pp.245-248
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• 2014

$Pt/Al_2O_3/Si_3N_4/SiO_2/Si$ charge trap flash memory structures with various thicknesses of the $Si_3N_4$ charge trapping layer were fabricated. According to the calculated and measured results, we depicted electron loss in a schematic diagram that illustrates how the trap to band tunneling and thermal excitation affects electrons loss behavior with the change of $Si_3N_4$ thickness, temperature and trap energy levels. As a result, we deduce that $Si_3N_4$ thicknesses of more than 6 or less than 4.3 nm give no contribution to improving memory performance.

• Journal of The Korean Association of Information Education
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• v.15 no.3
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• pp.439-447
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• 2011

In this paper, we developed the application for measure an area that it compute a space coordinate of real object to represent through a camera by using the Orientation sensor of smart devices. The application will help to solve a problems of an epistemological obstacles in an area learning. We conducted an expert evaluation for the application of educative usability, educative effect and etc.. The expert group was comprised of elementary school teacher who teach curriculum of an area in mathematics. In result, it was positively evaluated in terms of educative usability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1799-1818
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• 2018

Malware detections continue to be a challenging task as attackers may be aware of the rules used in malware detection mechanisms and constantly generate new breeds of malware to evade the current malware detection mechanisms. Consequently, novel and innovated malware detection techniques need to be investigated to deal with this circumstance. In this paper, we propose a new secure malware detection system in which API call fragments are used to recognize potential malware instances, and these API call fragments together with the homomorphic encryption technique are used to construct a privacy-preserving Naive Bayes classifier (PP-NBC). Experimental results demonstrate that the proposed PP-NBC can successfully classify instances of malware with a hit-rate as high as 94.93%.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.3
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• pp.329-347
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• 2018

The Smoothed Particle Hydrodynamics (SPH) method has proved to have great potentials in dealing with the wave-structure interactions. Compared with the Weakly Compressible SPH (WCSPH) method, the ISPH approach solves the pressure by using the pressure Poisson equation rather than the equation of state. This could provide a more stable and accurate pressure field that is important in the study of wave-structure interactions. This paper improves the solid boundary treatment of ISPH by using a high accuracy Simplified Finite Difference Interpolation (SFDI) scheme for the 2D wave-structure coupling problems, especially for free-moving structure. The proposed method is referred as the ISPH_BS. The model improvement is demonstrated by the documented benchmark tests and laboratory experiment covering various wave-structure interaction applications.

• Communications of Mathematical Education
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• v.30 no.3
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• pp.309-333
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• 2016

This study is part of app development research based on user centered design which targets silver generation learners. The mathematical contents provided by Senior math application focus on Numeracy issues. In order to finalize the user interface and the mathematical contents which is for developing the mathematic application, teaching experiment was carried out through 9 senior learners. Also CIPP program evaluation model was used for monitoring the result of this teaching experiment. Factors such as 'educational objectives' 'requirement analysis' 'educational environment' 'curriculum' 'learning content' 'learning matter' 'interaction' 'program administration' 'supporting environment' 'satisfaction' 'study result' 'substantiality of learning' were checked and as a result the Senior Mathematic application was developed through these feedbacks.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.2
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• pp.1-10
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• 2016

A system which provides multispectral near-IR and visible gray images of objects is constructed and an algorithm is derived to acquire a natural color image of objects from the gray images. A color image of 24 color patches is obtained by recovering their CIE (International Commission on Illumination) LAB color coordinates $L^*$, $a^*$, $b^*$ from their gray images using the algorithm based on polynomial regression. The system is composed of a custom-designed LED illuminator emitting multispectral near-IR illuminations, fluorescent lamps and a monochrome digital camera. Color reproducibility of the algorithm is estimated in CIELAB color difference ${\Delta}E^*_{ab}$. And as a result, if yellow and magenta color patches with around 10 ${\Delta}E^*_{ab}$ are disregarded, the average ${\Delta}E^*_{ab}$ is 2.9, and this value is within the acceptability tolerance for quality evaluation for digital color complex image.

• East Asian mathematical journal
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• v.34 no.4
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• pp.511-536
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• 2018

There is currently a growing need to nurture creative and convergent talent in the face of the fourth Industrial Revolution. Developing such talent requires interdisciplinary convergent education across the science, engineering, humanities, social studies, and arts disciplines. Such interdisciplinary convergence could cultivate humanities and social knowledge and qualities along with scientific expertise. In Korea, there are currently six science schools for the gifted that aim to discover and nurture science, technology, engineering, and mathematics (STEM) researchers from an early stage, and two science and art schools for the gifted that aim to cultivate new talent combining students' scientific and artistic qualities. These schools establish and follow curriculums that are suited to achieving the education objectives guaranteed by the Gifted Education Promotion Act and its Enforcement Decrees. This study compares the curriculums and curriculum tables of the science schools for the gifted to those of the science and art schools for the gifted to evaluate their methods of operation and performance. Additionally, it determines which curriculums provide an opportunity for students to nurture convergent thinking, and discusses how suitable curriculums could be implemented to develop convergent thinking.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.3
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• pp.235-245
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• 2019

This research focuses on the relationships among customer satisfaction, delight, and loyalty. Although customer delight is one facet of an affective evaluation that can be predicted from customer satisfaction as cognitive component of the evaluation, there is no empirical examination on the casual relationship among customer satisfaction, delight, and loyalty. This study aims at addressing this gap in the service literature. The research questions are (1) How is customer satisfaction related to customer delight? and (2) Does customer delight matter in the relationship between customer satisfaction and loyalty? Data from a survey of consumers across upscale restaurant and retail bank in Korea were obtained. Our results show that customer satisfaction contributes positively to customer delight, and that customer delight plays a significant role in the relationship between customer satisfaction and loyalty. This chained relationship from customer satisfaction to customer delight to customer loyalty suggests that achieving customer delight represents one of the underlying pathways through which basic or core requirements expected by customers are satisfied. Our finding suggests that service firms need to monitor and manage their levels of customer delight as a performance metric, and delighting customers may be an important strategy to build competitive advantage through customer loyalty.

• Communications for Statistical Applications and Methods
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• v.14 no.1
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• pp.169-182
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• 2007

Receive operating characteristic (ROC) approach can be employed to rank candidate genes from a microarray experiment, in particular, for the biomarker development with the purpose of population screening of a cancer. In the cancer microarray experiment based on n patients the researcher often wants to compare the tumor tissue with the normal tissue within the same individual using a common reference RNA. Ideally, this experiment produces n pairs of microarray data. However, it is often the case that there are missing values either in the normal or tumor tissue data. Practically, we have $n_1$ pairs of complete observations, $n_2$ "normal only" and $n_3$ "tumor only" data for the microarray. We refer to this data set as a mixed data set. We develop a ROC approach on the mixed data set to rank candidate genes for the biomarker development for the colorectal cancer screening. It turns out that the correlation between two ranks in terms of ROC and t statistics based on the top 50 genes of ROC rank is less than 0.6. This result indicates that employing a right approach of ranking candidate genes for the biomarker development is important for the allocation of resources.

• Journal of the Korean Data and Information Science Society
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• v.27 no.6
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• pp.1557-1564
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• 2016

Recently, an extended warranty of a system following the expiration of the basic warranty is becoming increasingly popular to the user. In this respect, we suggest a two stage maintenance policy under the non-renewing warranty from the user's point of view in this paper. In the first stage, the user has to decide whether or not to purchase the extended warranty period. And, in the second stage, the optimal replacement period following the expiration of the warranty is determined. Under the extended warranty, the failed system is minimally repaired by the manufacturer at no cost to the user. We utilize the expected cost from the user's perspective to determine the optimal two stage maintenance policy. Finally, a few numerical examples are given for illustrative purpose.