• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.61-71
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• 2014

As the occupancy rate of the flash memory increases in the storage media market for the embedded system and the semi-conductor industry grows, the demand and supply of flash memory is increasing by a big margin. They are especially used in large quantity in the smart phones, tablets, PC, SSD and Soc(System on Chip) etc. The flash memory is divided into the NOR type and NAND type according to the cell arrangement structure and the NAND type is divided into the SLC(Single Level Cell) and MLC(Multi Level Cell) according to the number of bits that can be stored in each cell. Many tests have been performed on NOR type such as BIST(Bulit-In Self Test) and BIRA(Bulit-In Redundancy Analysis) etc, but there is little study on the NAND type. For the case of the existing BIST, the test can be proceeded using external equipments like ATE of high price. However, this paper is an attempt for the improvement of credibility and harvest rate of the system by proposing the BIST for the MLC NAND type flash memory of Finite State Machine structure on which the pattern test can be performed without external equipment since the necessary patterns are embedded in the interior and which uses the MLC NAND March(x) algorithm and pattern which had been proposed for the MLC NAND type flash memory.

• Korean Journal of Childcare and Education
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• v.10 no.2
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• pp.111-131
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• 2014

This study aims to research the use of smart devices of infants and preschool children, and their mothers' perception about it. Moreover, the goal of this study is to collect preliminary data about problems from the use of smart devices, and to prevent the problems. Therefore, the questions of inquiry for this study are: 1. How do infants and preschool children use smart devices? 2. How do mothers perceive their children using smart devices? Four hundred and forty mothers, who send their child to a day-care center or kindergarten in Busan, participated in this research and data among 397 of them were analyzed using PASW 18.0 program. The answers to a multiple-choice question were converted into a frequency and percentage. To verify the difference of factors, Chi-squared Test and One-way Analysis of Variance methods were used. The following are findings of this study: 1. Most of the families owning smart devices allow their children to use a smart device when children want it, and children use it for entertainment purpose before their bedtime. Children start to use a smart device mostly around the age of 4. Compared to girls, boys spend a longer time on smart devices playing mobile game. In addition, the research indicated that the children of younger mothers tend to use smart devices in earlier ages than the children of elder mothers. 2. Mothers of preschool children have higher perception about the availability of their child using smart devices compare to the mothers of day-care center. However, the research showed that elder mothers have more positive perceptions about all the other five lower factors, (e.g. educational characteristic, entertainment characteristic, design, safety, and smart recognition).