• Journal of Digital Convergence
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• v.20 no.3
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• pp.343-348
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• 2022

Recently, With the recent rapid development of technology, the amount of data generated by various systems is increasing, and enterprise servers and data centers that have to handle large amounts of big data need to apply high-stability and high-performance storage devices even if costs increase. In such systems, SSD(solid state disk) that provide high performance of read/write are often used as storage devices. However, due to the characteristics of reading and writing on a page-by-page basis, erasing operations on a block basis, and erassing-before-writing, there is a problem that performance is degraded when duplicate writes occur. Therefore, in order to delay this performance degradation problem, over-provision technology of SSD has been applied internally. However, since over-provided technologies have the disadvantage of consuming a lot of storage space instead of performance, the application of inefficient technologies above the right performance has a problem of over-costing. In this paper, we proposed a method of measuring the performance and cost incurred when various over-provisions are applied in an SSD and predicting the system-optimized over-provided ratio based on this. Through this research, we expect to find a trade-off with costs to meet the performance requirements in systems that process big data.

• The Journal of Korean Medicine
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• v.41 no.2
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• pp.1-8
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• 2020

Objectives: To establish the expiration date of herbal decoction pouch, the change in antimicrobial activities was measured according to storage temperature and period. Methods: Five herbal formulas, Gyeji-tang, Jakyakgamcho-tang, Saengmaek-san, Paljung-san, and Dangguisu-san, with antimicrobial activity were selected from 51 herbal formulas commonly used in traditional Korean medical institutions. Five herbal formula decoction pouches were prepared and stored at room temperature (RT) or 4℃ from 0 to 12 weeks to evaluate the antimicrobial activity against Bacillus cereus, Listeria monocytogenes, or Vibrio parahaemolyticus. The antimicrobial activities were evaluated by the disk diffusion method (disk size: 10 mm). Results: The decoction pouches of Gyeji-tang and Jakyakgamcho-tang maintained antimicrobial activity against V. parahaemolyticus from week 0 (14 mm) to week 12 (14 mm) at both temperatures. Saengmaek-san pouch had antimicrobial activities against V. parahaemolyticus and B. cereus from week 0 (19 mm and 20 mm) to week 12 (both 18 mm), respectively. At RT and 4℃, the antimicrobial activity of Paljung-san pouch was maintained week 0 (17 mm) to week 12 (both 13 mm) against B. cereus. Against L. monocytogenes, the antimicrobial activity of Dangguisu-san pouch showed 27 mm at week 0 and 23 mm (RT) and 24 mm (4℃) at week 12, respectively. Conclusion: According to increase of the storage duration, the antimicrobial activities of 5 herbal formula decoction pouches decreased slightly but remained up to 12 weeks. These results can be used as important data to establish the expiration date of herbal formula decoction pouches.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.780-785
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• 2003

Recently the trends in information storage devices need small size, mobility, high capacity, and low power consumption etc. To satisfy those, the development of high performance actuator is an important issue. Compared with general linear actuator for optical disk drive, swingarm type rotary actuator is suitable to design in small form factor and has fast access time for random access. Swingarm actuator is designed considering the structural problem and the actuating force of VCM(Voice Coil Motor). The increase of mass caused by optical components makes vibration problems of swing-arm, therefore resonance frequency should be increased and inertia has to be reduced. ANSYS FEM tool is employed in optimizing swingarm. The VCM is designed using 3-D electro-magnetic analysis, and parameters of magnetic circuit are determined to matte large flux density. The large flux density enables to achieve low power consumption. VCM holder is designed to get the mass balance of total actuator and this balance reduces the magnitude of critical mode relative to pivot bearing, It is expected that swingarm type rotary actuator designed by this method is available to variable type of micro optical disk drives.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.1
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• pp.37-46
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• 2010

A Suffix Tree is an efficient data structure that exposes the internal structure of a string and allows efficient solutions to a wide range of complex string problems, in particular, in the area of computational biology. However, as the biological information explodes, it is impossible to construct the suffix trees in main memory. We should find an efficient technique to construct the trees in a secondary storage. In this paper, we present a method for constructing a suffix tree in a disk for large set of DNA strings using new index scheme. We also show a typical application example with a suffix tree in the disk.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.767-774
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• 2010

Due to advantages of NAND flash memory such as non-volatility, low access latency, low energy consumption, light weight, small size and shock resistance, it has become a better alternative over traditional magnetic disk drives, and has been widely used. Traditional DBMSs including mobile DBMSs may run on flash memory without any modification by using Flash Translation Layer (FTL), which emulates a random access block device to hide the characteristics of flash memory such as "erase-before-update". However, most existing FTLs are optimized for file systems, not for DBMSs, and traditional DBMSs are not aware of them. Also, traditional DBMSs do not consider the characteristics of flash memory. In this paper, we propose a flash-conscious storage system for DBMSs that utilizes flash memory as a main storage medium, and carefully put the characteristics of flash memory into considerations. The proposed flash-conscious storage system exploits log records to avoid costly update operations. It is shown that the proposed storage system outperforms the state.

• YAKHAK HOEJI
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• v.39 no.4
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• pp.438-443
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• 1995

Four different pseudopolymorphs of amoxicillin-trihydrate, dehydrate, monohydrate and anhydratewere prepared and characterized by UV spectrophotometry, DSC, and TGA. In vitro dissolution studies of four pseudopolymorphs were carried out in pH 6.8 phosphate buffer at $37^{\circ}C$ by means of a rotating disk method. The effect of four pseudopolymorphs on bioavauability of amoxicillin was studied in healthy 6 subjects using urinary excretion method. The dissolution result was shown in the sequence, trihydrate(95.5%)>monohydrate(83.5%)>anhydrate(67.6%)>dihydrate(15.8%). The urinary excretion rate of anhydrate could not be detected and the dissolution results agreed well with in vivo phannacoldnetic study results. The effects of storage conditions, milling and compression on the pseudopolymorpnc transformation were investigated by thermal methods. The results showed that four pseudopolymorphs were not transformed and they were very stable.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.844-848
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• 2004

We evaluate the durability of vehicle chassis component under dynamic loadings. Since the fatigue analysis of vehicle component is based on the dynamic load history it must be done by dynamic analysis. But in case the vehicle component has natural frequencies much larger than reversing frequencies of load history, we can get small analysis errors by applying quasi-static analysis. So it is inefficient that we apply to the dynamic analysis for all the vehicle components. In this research, we discuss the quasi-static analysis method which is appropriate for the fatigue analysis. And in case we can only perform the fatigue analysis based on dynamic analysis, we introduce more efficient method in the analysis time and hard disk storage.

• Nutrition Research and Practice
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• v.1 no.4
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• pp.273-278
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• 2007

The objective of this study was to evaluate the inhibitory activity of natural products, against growth of Escherichia coli (ATCC 25922) and Salmonella typhimurium (KCCM 11862). Chitosan, epigallocatechin gallate (EGCG), and garlic were used as natural bioactives for antibacterial activity. The testing method was carried out according to the disk diffusion method. All of chitosan, EGCG, and garlic showed inhibitory effect against the growth of E. coli and Salmonella typhi. To evaluate the antibacterial activity of natural products during storage, chicken skins were inoculated with $10^6$ of E. coli or Salmonella typhi. The inoculated chicken skins, treated with 0.5, 1, or 2% natural bioactives, were stored during 8 day at $4^{\circ}C$. The numbers of microorganisms were measured at 8 day. Both chitosan and EGCG showed significant decrease in the number of E. coli and Salmonella typhi in dose dependent manner (P < 0.05). These results suggest that natural bioactives such as chitosan, EGCG may be possible to be used as antimicrobial agents for the improvement of food safety.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1399-1404
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• 1990

There is an increasing need to apply artificial intelligence to the real application fields of industry. These include an intelligent process control, an expert machine and a diagnostic and/or maintenance machine. These applications are implemented in AI Languages. It is commonly recognized that AI Languages, such as Common Lisp or Prolog, require a workstation. This is mainly due to the fact that both languages need a large amount of memory space and disk storage space. Workstations are appropriate for a laboratory or office environment. However, they are too bulky to use in the real application fields of industry or business. Also users who apply artificial intelligence to these fields wish to have their own operating systems. We propose a new design method of an intelligent controller which is embedded within equipment and provides easy-to-use tools for artificial intelligence applications. In this paper we describe the new design method of a VMEbus based intelligent controller for artificial intelligence applications and a small operating system which supports Common Lisp and Prolog.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.607-615
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• 2015

Mosts user of internet and smart phone has certificate, and uses it when money transfer, stock trading, on-line shopping, etc. Mosts user stores certificate in a hard disk drive of PC, or the external storage medium. In particular, the certification agencies are encouraged for user to store certificate in external storage media such as USB memory rather than a hard disk drive. User think that the external storage medium is safe, but when it is connect to a PC, certificate may be copied easily, and can be exposed to hackers through malware or pharming site. Moreover, if a hacker knows the user's password, he can use user's certificate without restrictions. In this paper, we suggest secure management scheme of the private key file using a password of the encrypted private key file, and a USB Memory's hardware information. The private key file is protected safely even if the encrypted private key file is copied or exposed by a hacker. Also, if the password of the private key file is exposed, USB Memory's container ID, additional authentication factor keeps the private key file safe. Therefore, suggested scheme can improve the security of the external storage media for certificate.