• Korean Journal of Cognitive Science
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• v.19 no.4
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• pp.369-396
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• 2008

The purpose of this article is to investigate the effect of visual working memory, the types and contents of graphic annotations on English learning. The participants of the experiments were 5th and 6th graders. The result showed that animation was effective only in the word test for children with large visual working memory, whereas text-only-annotation yielded better performance in the comprehension test in Experiment 1. The effect of relevance of animations was tested in Experiment 2. Context-relevant-animations yielded better comprehension than the animations denoting the typical meaning, whereas the opposite pattern was reported in the word test. The result of the two experiments was interpreted in terms of cognitive load theory and the generative theory of multimedia learning.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.2
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• pp.27-34
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• 2013

NAND Flash Memory has been used in several devices by low cost and high capacity, and the demand for mass NAND Flash Memory has increased due to the multimedia extension of mobile devices. The JFFS2, NILFS2, and YAFFS2 file systems are used mainly in NAND Flash Memory. In this paper, the performance of Sequential read/write of the 3 file systems are analyzed for the 4 I/O schedulers : CFQ(Complete Fair Queuing) I/O scheduler, NOOP(No Operation) I/O scheduler, Anticipatory I/O scheduler, and Deadline I/O scheduler. In JFFS2 file system, Anticipatory I/O scheduler has the best performance by 8% decreasing speed in writing time and 1.5% decreasing speed in reading time compared to the other I/O scheduler. In YAFFS2 file system, it results are similar to performance in reading and writing for the 4 I/O schedulers. In NILFS2 file system, NOOP I/O scheduler has 2% faster in writing and Deadline I/O scheduler has 6% faster in reading than other I/O schedulers.

• Journal of Biomedical Engineering Research
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• v.35 no.4
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• pp.99-104
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• 2014

Generally, human eye blinks are closely associated with the cognitive state or visual attention such as attentional requirements on visual stimuli. These previous studies have reported that eye blinks are related to explicit visual attention using blink rate, pattern and blink timing across subjects. However, these results have been obtained in a well-controlled experimental settings. So, it would prove difficult to investigate human's natural response in a continuous and realistic situation. In our study, we measured the eye blink intervals while participants viewed a movie clip. And we analyzed the blink interval data for relationship between visual attention and eye blink intervals. 24 participants took part in two experimental sessions, first session to measure the IEBI while viewing the movie clip and second session to conduct a memory performance test using a self-questionnaire, which were spaced 3 weeks apart. The results indicate significantly higher memory performance at long IEBI period than short IEBI period while watching a movie clip(t = 3.257, df = 17, p < 0.005, 2-tailed). In addition, memory performance score significantly correlated with the IEBI value(spearman's rho = 0.40, N = 36, p < 0.01, 2-tailed). Our results suggest that IEBI is used to measure or assess visual attention while wiewing the movie that it is capable of simulating aspects of real-life experiences by visual attention. Thus, we expect IEBI to be used to measure or assess our visual attention, cognition, further emotion about not only movies, advertisements and other cultural contents but also cognitive science.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.5
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• pp.703-717
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• 2002

This paper illustrates the implementation of a scalable shared buffer asynchronous transfer mode (ATM) switch. The designed shared buffer ATM switch has a shared buffet of a pipelined memory which has the access time of 4 ns. The high-speed buffer access time supports a possibility of the implementation of a shared buffer ATM switch which has a large switching capacity. The designed switch architecture provides flexible switching performance and port size scalability with the independence of queue address control from buffer memory control. The switch size and the buffer size of the designed ATM switch can be reconfigured without serious circuit redesign. The designed prototype chip has a shared buffer of 128-cell and 4 ${\times}$ 4 switch size. It is integrated in 0.6um, double-metal, and single-poly CMOS technology. It has 80MHz operating frequency and supports 640Mbps per port.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.1
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• pp.70-74
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• 2010

As the storage capacity of the flash memories increased portable devices began to store mass amount of multimedia data on flash memory. Therefore, there has been a need for an effective data management scheme by indexing structure. Among many indexing schemes, M-tree is well known for it's suitability for multimedia data with high dimensional matrix space. Since flash memories have writing operation restriction, there is a performance limitation in indexing scheme with frequent write operation. In this paper, a new node split method with reduced write operation for m-tree indexing scheme in flash memory is proposed. According to experiments the proposed method reduced the write operation to about 7% of the original method. The proposed method will effectively construct an indexing structure for multimedia data in flash memories.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.115-117
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• 2022

Whitebox encryption technique is a method of preventing exposure of encryption keys by mixing encryption key information with a software-based encryption algorithm. Whitebox encryption technique is attracting attention as a technology that replaces conventional hardware-based security encryption techniques by making it difficult to infer confidential data and keys by accessing memory with unauthorized reverse engineering analysis. However, in the encryption and decryption process, a large lookup table is used to hide computational results and encryption keys, resulting in a problem of slow encryption and increased memory size. In particular, it is difficult to apply whitebox cryptography to low-cost, low-power, and light-weight Internet of Things products due to limited memory space and battery capacity. In addition, in a network environment that requires real-time service support, the response delay time increases due to the encryption/decryption speed of the whitebox encryption, resulting in deterioration of communication efficiency. Therefore, in this paper, we analyze whether the AES-based whitebox(WBC-AES) proposed by S.Chow can satisfy the speed and memory requirements based on the experimental results.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.617-619
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• 2004

Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time in. Today any data storage system can not satisfy these conditions, but holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System architecture without mechanical actuating part is possible, so fast data transfer rate and high storage capacity about $1Tb/cm^3$ can be realized. In this paper, to correct errors of binary data stored in holographic digital data storage system, find cluster centers using subtractive clustering and reduce intensities of pixels around centers, so the intensify profile of data rare will be uniform and the better data storage system can be realized.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1076-1079
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• 2005

Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time in. Today any data storage system can not satisfy these conditions, but holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System architecture without mechanical actuating part is possible, so fast data transfer rate and high storage capacity about 1Tb/cm3 can be realized. In this paper, to correct errors of binary data stored in holographic digital data storage system, find cluster centers using clustering algorithm and reduce intensities of pixels around centers. We archive the procedure by two algorithms of C-mean and subtractive clustering, and compare the results of the two algorithms. By using proper clustering algorithm, the intensity profile of data page will be uniform and the better data storage system can be realized.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.4
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• pp.175-184
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• 2010

This paper designs a virtual USB drive for mobile devices which gives an illusion of a traditional USB flash memory drive and provides capacity-free storage space over IP network. The virtual USB drive operating with a S3C2410 hardware platform and embedded linux consists of USB device driver, an iSCSI-enabled network stack, and a seamless USB/iSCSI tunneling module. For performance enhancement, it additionally provides a kernel-level seamless USB/iSCSI tunneling module and data sharing with symbol references among kernel modules. Experiments reveal that the kernel-level implementation can improve the I/O performance up to 8 percentage, as compared with the user-level implementation.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2590-2593
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• 1999

This paper describes the development of Emergency Generator Equipments Diagnosis System for monitoring generator equipments and battery system. This system is capable of measuring on up to 20 separate sites of generator, engine and periphral equipment's. Battery system also capable of measure the setting time, float and discharge voltage of up to 240 cells in a single installation, and has the memory capacity to store battery's alarm data information on up to 200 separate sites. This system are easy to maintain and attain cost effectively, so that prepared for meeting the customer's service needs immediately. The system is additionally programmed with a each model, that will enable to accurately determine the generator equipments and remain battery capacity in a system following a short discharge test. It is also equipped with remote interrogation and control facilities.