• Journal of the Korean Magnetics Society
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• v.7 no.1
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• pp.13-18
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• 1997

The effects of the various raw material composition and sintered temperature on the physical properties of Ni-Zn ferrite have been investigated. They turned out to be spinel structure by X-ray diffraction and the size of grain from microscope was from 6 ${\mu}{\textrm}{m}$ to 16 ${\mu}{\textrm}{m}$. As the sintering temperature was increased from 1030 $^{\circ}C$ to 1070 $^{\circ}C$, the initial permeability and magnetic induction has increased and the both of Q factor and coercive force has decreased. The coercive force and curie temperature were almost the same at each specimen. Their values were about 0.20 Oe and 220 $^{\circ}C$. The frequency of specimen will used in the range from 400 kHz to 20 MHz. The basic composition of $Ni_{0.14}Zn_{0.64}Cu_{0.22}Fe_2O_4$ (specimen B) sintered at 1050 $^{\circ}C$ shows the best results at magnetic induction($B_r & B_m$).

• Journal of the Korean Society of Costume
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• v.61 no.5
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• pp.64-76
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• 2011

Consumers attribute human personality to products or stores as well as brands. As brand personality is imprinted to a consumer's mind, in e-commerce, the concept of store personality needs to be examined by comprehending the e-brand personality. Unlike the recent studies that focus primarily on the portal site, we attempt to identify e-brand personality of online shopping malls that sell fashion products. This study also examined the impact of the parent company's attributes on e-brand personality. A survey was conducted to 240 females and 240 males in their 20s or 30s. E-brand personality of three different types of the Internet shopping mall was evaluated by 160 respondents, respectively. As a result, we found that Internet shoppers perceive that e-brands have four distinct personality dimensions: young, reliable, sophisticated, and creative. Among the four dimensions, "young" and "reliable" showed the most significant influence on intention to visit the shopping mall site. Besides, e-brand personality varied with parent companies' attributes such as reputation, credibility, and fashion industry-relatedness. Especially, credibility of the parent company showed a strong positive relationship with e-brand personality.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.724-737
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• 2020

Corrected Block TEA(or XXTEA) is a block cipher designed to correct security weakness in the original block TEA in 1998. In this paper, XXTEA cipher hardware which can encrypt or decrypt between 64-bit and 256-bit messages using 128-bit master key is implemented. Minimum message block size is 64-bit wide and maximal message block size is 256-bit wide. The designed XXTEA can encrypt and decrypt variable-length message blocks which are some arbitrary multiple of 32 bits in message block sizes. XXTEA core of this paper is described using Verilog-HDL and downloaded on Vertex4. The operation frequency is 177MHz. The maximum throughput for 64-bit message blocks is 174Mbps and that of 256-bit message blocks is 467Mbps. The cryptographic IP of this paper is applicable as security module of the mobile areas such as smart card, internet banking, e-commerce and IoT.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.902-905
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• 2004

A heart diagnosis system adopts Superconducting Quantum Interface Device(SQUID) sensors for precision MCG signal acquisitions. Such system is composed of hundreds of sensors, requiring fast signal sampling and precise analog-digital conversions(ADC). Our development of hardware board, processing 64-channel 12-bit 1ks/s, is built by using 8-channel ADC chips, 8-bit microprocessors, SPI interfaces, and parallel data transfers between microprocessors to meet the 1ks/s, i.e. 1 ms speed. The test result shows that the signal acquisition is done in 168 usuc which is much shorter than the required 1 ms period. This hardware will be extended to 256 channel data acquisition to be used for the diagnosis system.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.208.1-208.1
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• 2003

We synthesized naphthazarin derivatives from shikonin, a major compound from Lithospermum erythrorhion Sieb et ZUCC. Of derivatives, DMNQ S64, 2-or 6-(l-hydroxyiminoalkyl) effectively showed antitumor activity on A549, human lung cancer cells (IC$\sub$50/= 30 ${\mu}$M). It significantly inhibited prostaglandin E$_2$(IC$\sub$50/= 10 ${\mu}$M). We also confirmed it selectively downregulated the expression of cyclooxygenase 2(COX-2), while it didn't affect COX-1. The induction of apoptosis by DMNQ S64 is underway.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.641-644
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• 2003

Sea level variability and eddy in the Amsterdam-Crozet-Kerguelen region of the South Indian Ocean were studied during 1 year(October 15, 1992~October 15, 1993) using multi-satellite data(Topex/Poseidon, ERSl) produced by signal treatement. We found that generally sea level variabilities(>10cm) exist along the Antarctic Circumpolar Current in the area of 35$^{\circ}$~46$^{\circ}$S and especially strong sea level variabilities(20~30cm) were occurred by the effects of eddy due to botton topography in two small area: 49$^{\circ}$-57$^{\circ}$E and 38$^{\circ}$~42$^{\circ}$S, and 58$^{\circ}$ -64$^{\circ}$E and 42$^{\circ}$-44$^{\circ}$S.

• Korean Journal of Remote Sensing
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• v.19 no.4
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• pp.271-276
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• 2003

Sea level variability and eddy in the Amsterdam-Crozet-Kerguelen region of the South Indian Ocean were studied during 1 year (October 15, 1992~October 15, 1993) using multi-satellite data (Topex/Poseidon, ERS1) produced by signal treatment. We found that sea level variabilities (>10cm) generally exist along the Antarctic Circumpolar Current in the area of 35$^{\circ}$~46$^{\circ}$S and strong sea level variabilities (20~30cm) were especially occurred from the effects of eddy due to bottom topography in two small area: 49$^{\circ}$~57$^{\circ}$E and 38$^{\circ}$~42$^{\circ}$S, and 58$^{\circ}$~64$^{\circ}$E and 42$^{\circ}$~44$^{\circ}$S.

• Korean journal of applied entomology
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• v.31 no.1
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• pp.1-6
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• 1992

These studies were carried out to compare toxicological test methods of two spotted spider mite, Tetranychus urticae Koch,; and to investigate relationship between in vivo resistant level of highly acaricide-selected population, and in vitro insensitivity of the AChE in the same population to carbophenothion and ethion. The slide dip method (CV = 8.7%) was of more accuracy and suitability than that of the leaf dip method(CV=12.2%) and leaf disc method (CV= 13.6 %) in determination of the resistant levels of twospotted spider mite to acaricides. The slide dip method also had the advantages of simple treatment with different populations on a slide at the same time, standardization of post-treatement conditions and living plants exclud¬ed from the test. Even though the topical application method(CV =8.1 %) showed high accuracy, it had the demerits of the much time consuming, need of expensive equipment and difficulty of test manipulation. For a limited time, the 22nd successive carbophenothion-selected population of two-spotted spider mite showed 156- and 128-fold resistant levels to carbophenothion and ethion(both alPs), respectively. However, the 24th successive ethion-selected population revealed 64.1- and 65-fold resistant levels to ethion and carbophenothion, respectively. In the inhibition of AChE activity, the carbophenothion-selected population showed 3.3- and 2.7-fold insensitivity in AChE activity to carbophenothion and ethion, respectively. Likewise, the ethion -selected population exhibited 3- and 2.6-fold insensitivity in AChE activity to carbophenothion and ethion, respectively, as compared with that of susceptible population. As a result, a good relation was recognized between in vivo resistance to organophosphorous acaricides and in vitro insensitivity of the AChE to corresponding inhibitors.

• Mycobiology
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• v.36 no.2
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• pp.102-105
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• 2008

The acetylcholinesterase (AChE) inhibitor of Yarrowia lipolytica S-3 was maximally produced when it was incubated at $30^{\circ}C$ for 36 h in an optimal medium containing 1% yeast extract, 2% peptone and 2% glucose, with an initial pH 6.0. The final AChE inhibitory activity under these conditions was an $IC_{50}$ value of 64mg/ml. After partial purification of the AChE inhibitor by means of systematic solvent extraction, the final $IC_{50}$ value of the partially purified AChE inhibitor was 0.75 mg/ml. We prepared a test product by using the partially purified AChE inhibitor and then determined its stability for the development of a new antidementia commercial product. The test product was stable at room temperature for 15 weeks.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.127.2-127.2
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• 2016

연구된 Si위의 흡착원자들의 확산 메커니즘들에 비해 Ge 표면에서의 확산 메커니즘은 잘 알려져 있지 않다. 최근 연구에 따르면, 수소가 덮인 Ge(110) 표면에서 그래핀 결정 핵생성은 비등방적이며, 낟알 둘레없이 웨이퍼 크기로 성장시킬 수 있음을 보였다. 본 연구에서는 VASP(Vienna Ab-initio Simulation Package)의 NEB(Nudged Elastic Band) 방법을 이용하여 수소가 덮인 Ge(110) 표면과 청결한 표면에서 탄소원자의 확산 과정과 확산에 따른 에너지 장벽을 계산 하였다. 계산 결과 수소가 덮인 표면에서의 탄소원자 확산은 체인 방향으로 각각 3.29 eV, 2.67 eV의 에너지 장벽을 가지고 청결한 표면에서는 탄소원자가 게르마늄 연결을 치환하며 확산한다. 이때 에너지 장벽은 0.82 eV이고 치환된 게르마늄이 확산할 때는 각각 0.64 eV, 0.59 eV의 에너지 장벽을 넘어야 한다. 결과적으로 수소가 덮인 표면에서보다 청결한 표면에서 탄소 확산 에너지 장벽이 낮으며, 청결한 표면에서는 탄소가 게르마늄을 치환하고 치환된 게르마늄이 확산할 확률이 높음을 알 수 있었다.