• Journal of the Korean Ceramic Society
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• v.38 no.11
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• pp.1023-1029
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• 2001

Hexagonal ferrite $Co_2$Z(B $a_3$ $Co_2$F $e_{24}$ $O_{41}$ ) was prepared by various coprecipitation-oxidation methods. The formation of $Co_2$Z was studied in order to determine the optimal method. The $Co_2$Z composition hydroxides were prepared with the different oxidation and precipitation from the aqueous solution of $Ba^{2+}$, $Co^{2+}$ and F $e^{2+}$ chloride mixture. The coprecipitates were heat-treated at various temperatures, and their formation phases and microstructures were investigated from the analyses of DTA/TGA, powder XRD and SEM. The $Co_2$Z phase was observed in the case where the precursor will have the amorphous like oxyhydoxide($\delta$-FeOOH), and formed from $Ba_3$F $e_{32}$ $O_{51}$ , BaF $e_{12}$ $O_{19}$ (M-type) and $Ba_2$ $Co_2$F $e_{12}$ $O_{22}$ (Y-type). The $Co_2$Z was synthesized by the heat-treatment of the coprecipitate, which was prepared from the precipitation after oxidizing the chloride mixed solution, above 110$0^{\circ}C$.EX>.

• The Journal of Korean Association of Computer Education
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• v.9 no.3
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• pp.67-74
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• 2006

The purpose of this study is identifying variables that affect to learners' preference toward specific e-learning programs, using an exploratory factor analysis(EFA) method. We extract common factors that explain the correlations among variables. In the result, 8 factors were identified as main influential factors: e-learning program design(1st factor), the purpose of e-learning use(2nd factor), social and cultural issues(3rd factor), demographics(4th factor), organizational needs(5th factor), impacts of e-learning(6th factor), e-learning management(7th factor), and technical issue(8th factor).

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.16 no.2
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• pp.123-126
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• 2013

$M\acute{e}n\acute{e}$trier's disease is a rare protein-losing gastropathy characterized by hypertrophic gastric fold, foveolar hyperplasia, and hypoproteinemia with resulting peripheral edema. It is clinically evident as nonspecific gastrointestinal symptoms, including abdominal discomfort, nausea and vomiting, abdominal pain, weight loss, diarrhea, and edema. Pediatric $M\acute{e}n\acute{e}$trier's disease usually has an insidious onset and progressive, chronic clinical course and it spontaneously resolves in weeks or months. The pathogenesis of $M\acute{e}n\acute{e}$trier's disease is not clearly understood. $M\acute{e}n\acute{e}$trier's disease is thought to be associated with some gastric infections. But the cause of $M\acute{e}n\acute{e}$trier's disease is unknown, an association with cytomegalovirus (CMV) and Helicobacter pylori has been suggested. In Korea, We present the first a case of pediatric $M\acute{e}n\acute{e}$trier's disease with positive evidence of CMV and H. pylori.

• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.506-515
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• 2024

Primary human dermal papilla cells (HDPCs) are often preferred in studies on hair growth and regeneration. However, primary HDPCs are limited by their reduced proliferative capacity, decreased hair induction potential, and extended doubling times at higher passages. To overcome these limitations, pTARGET vectors containing human papillomavirus16 (HPV16) E6/E7 oncogenes were transfected into HDPCs and selected using G-148 to generate immortalized cells here. HPV16 E6/E7 oncogenes were efficiently transfected into primary HDPCs. Immortalized HDPC showed higher proliferative activity than primary HDPC, confirming an increased proliferation rate. Expression of p53 and pRb proteins was downregulated by E6 and E7, respectively. E6/E7 expressing HDPC cells revealed that cyclin-dependent kinase (CDK) inhibitor p21 expression was decreased, while cell cycle-related genes and proteins (CDK2 and cyclin E) and E2F family genes were upregulated. Immortalized HDPCs maintained their responsiveness to Wnt/β-catenin pathway and hair follicle formation capability, as indicated by their aggregative properties and stemness. E6/E7 immortalized HDPCs may facilitate in vitro hair growth and regeneration studies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1346-1353
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• 2001

This paper presents an algorithm for the design of 2 dimension separable denominator digital filter(SDDF). The proposed algorithm is based on the reduced dimensional decomposition not only 2 dimension SDDF's but also of given 2 dimension specification. The frequency domain design of 2 dimension separable denominator digital filters based on the reduced dimensional decomposition can be realized when the given 2 dimension frequency specification are optimally decomposed into a pair of 1 dimension digital filter specification via singular value decomposition. the algorithm is computationally efficient and numerically stable. In case of the low pass filter, the approximation error of the proposed design algorithm is $e_{m}$=5.17, $e_{r1}$ =8.78, $e_{r2}$=7.34, while in case of band pass filter, the approximation error is $e_{m}$=13.00, $e_{r1}$=62.76, $e_{r2}$=62.7676.7676

• Journal of Photoscience
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• v.6 no.2
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• pp.67-70
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• 1999

trans-1-(9-Anthryl)-2-(n-pyridyl)ethene (t-n-APyE, n=2 or 4) and trans-1-(9-anthryl)-2-pyrazinylethene (T-APzE) exhibits solvent-dependent fluorescence and efficient trans)cis photoisomerization. Photochemical reactivities of t-2-APyE, t-4-APyE, and t-APzE have been investigated in nonpolar and polar solvents. In nonpolar solvent, parallel photocyclization reaction occurs very efficiently in competition with the fluorescence and photoisomerization. But, in polar solvent, photocyclization was not observed. It is probably due to the stabilization of charge separated state in polar solvent, which is an intermediate in photoisomerization reaction.

• Journal of Information Technology Services
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• v.2 no.1
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• pp.75-83
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• 2003

Among EC areas. the B2B EC market is being spotlighted as an important interesting research area considering its size and the potential impact on companeies and the whole society. In comparison with private consumers in B2C EC. business buyers in B2B EC have to precisely keep track of the purchase records. and integrate them with the buyer's e-procurement system, which might have been implemented as a part of integrated ERP (Enterprise Resource Planning) systems. There are three approaches for such integration between ERP and e-marketplace in B2B EC; Two previous approaches are Inside-Out approach and Outside-In approach. And a newly, one is b-cart approach. In this paper, we try to survey these three approaches and make a comparison analysis. From this research. we identify that the b-cart approach is the most efficient framework in integrating ERP with e-marketplace in B2B EC.

• Analytical Science and Technology
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• v.25 no.6
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• pp.447-459
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• 2012

In this study, the emission characteristics of volatile and odorant species released from salted meat product (Spam) was investigated as a function of time. Gas samples released from Spam samples were analyzed for volatile organic compounds (VOC) and sulfur compounds (RSC) at five different times for the elapsed (E) days of 0, 1, 3, 6, and 9 (E-0 to E-9) by GC/MS and GC/PFPD system, respectively. Results indicated that reduced sulfur, aldehyde, and ketone groups were the dominant odorants. Especially, hydrogen sulfide was the predominant in concentration and odor activity value (OAV) during the fresh stage. Its concentration was 1465 ${\mu}g/m^3$ (60.0% of the total mass) in E-0 and 455 ${\mu}g/m^3$ (28.0%) in E-1, while its OAV was 19.4 (78.3%: E-0) and 6.02 (41.7%: E-1). On the other hand, the concentration of acetone showed the maximum values in the decaying stage (E-3: 451 (43.2%), E-6: 369 (64.2%), and E-9: 1150 ${\mu}g/m^3$ (70.2%)). Furthermore, the concentration of 2,3-butanedione was also detected considerably from decaying sample (E-3: 17.6 (1.68%), E-6: 16.1 (2.80%), and E-9: 179 ${\mu}g/m^3$ (10.9%)). However, OAV of acetone was insignificant (<0.01%) in the decaying stage, while that of 2,3-butanedione was relatively high in the range of 1.14-11.6 (14.5-76.2% of ${\Sigma}OAV$). It thus confirmed that the major odorant groups generated from Spam samples changed with the progress of decay such as sulfur (fresh stage), aldehyde (intermediate stage), and ketone compounds (decaying stage).

• Korean Journal of Plant Resources
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• v.13 no.1
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• pp.11-17
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• 2000

In an effort to produce high quality Angelica gigas in the southern area of Korea, a variety of mulching materials were used to prevent withering during the summer. The experimental results are summarized as follows. Soil water content and temperature under various mulching materials were higher than those without mulching, in all the cases studied. Among various mulching materials P. E.(polyethylene) mulching material showed the highest effect. The appearance of weeds was the lowest when using the black P. E. mulching, while growth of weeds was the greatest when using transparent mulching. Growth and development of the plant were better with P. E. mulching than straw mulching or no mulching, allowed for more and bigger leaves. The bolting rate was about 2∼5%, with a slightly larger value under P. E. mulching. Under P. E. mulching, probably due to good physical properties of the soil the number of roots was large, and the length and diameter were good. Active growth of roots under P. E. mulching resulted in a yield increase of the plant. The black P. E. mulching material showed a prominent effect on suppression of weed growth, and the black P. E. material was considered to be the most recommendable among various P. E. mulching materials when there is a lack of labor.

• Information Systems Review
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• v.5 no.2
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• pp.23-36
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• 2003

This study proposed the approaches to business process redesign and business network redesign in e-business environment through the case analysis of e-Transformation performed in Kolon Gloteck, Inc. which has been managed and operated in a traditional mode. The proposed e-Transformation approaches of the traditional firm in this study were as following: 1) Network-focused business process redesign; 2) Introducing ERP(Enterprise Resource Planning) as e-Business backbone; 3) Establishing transparence of business functions through using shared database; 4) Understanding customer and constructing IT(Information Technology) infrastructure for customer satisfaction; 5) Performing data and process standardization; 6) Applying the best suitable IT(Information Technology) such as JSP(Java Server Pages) and VPN(Virtual Private Network). The findings of this case study are thought to be useful as a practical guideline in carrying, out e-Transformation of the typical traditional firm and to provide significant basis for constructing the theoretical framework of e-Transformation methodology.