• YAKHAK HOEJI
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• v.29 no.1
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• pp.50-54
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• 1985

Seven different sorbents were evaluated for their adsorptivity and desorptivity of antibiotic, chloramphenicol. Among the sorbents studied, Carbopak B was found to be the most efficient in enriching the chloramphenicol from dilute aqueous solution. Interfering components in the milk matrix could be washed off by water and petroleum ether from Carbopak B column, while the chloramphenicol was retained on the surface of Carbopak B. The method of simple and efficient purification and enrichment of chloramphenicol using Carbopak B, followed by quantitative analysis employing $C_{18}$ reversed phase high performance liquid chromatography has been applied to the determination of chloramphenicol in milk.

• Journal of the Chungcheong Mathematical Society
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• v.18 no.1
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• pp.41-49
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• 2005

In this paper, we prove the generalized Hyers-Ulam- Rassias stability of the functional equation $$af(\frac{x+y+z}{b})+af(\frac{x-y+z}{b})+af(\frac{x+y-z}{b})+af(\frac{-x+y+z}{b})=cf(x)+cf(y)+cf(z)$$.

• East Asian mathematical journal
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• v.18 no.2
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• pp.205-209
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• 2002

In the paper the following propositions are proved. 1) If ($Q,{\cdot},e$) is a B-algebra, then there exists a group($Q,A,^{-1}$, 1) such that the following equalities hold e=1 and ${\cdot}=^{-1}A$, where $^{-1}A(x,y)=z{\Longleftrightarrow^{def}}A(z,y)=x$; and 2) If ($Q,A,^{-1}$, e) is a group, then ($Q,^{-1}A$, e) is a B-algebra.

• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.197-204
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• 2005

For two distinct rank-1 matrices A and B, a rank-1 matrix C is called a separating matrix of A and B if the rank of A + C is 2 but the rank of B + C is 1 or vice versa. In this case, rank-1 matrices A and B are said to be separable. We show that every pair of distinct Boolean rank-l matrices are separable.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.843-844
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• 2012

• Biomedical Science Letters
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• v.18 no.3
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• pp.283-290
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• 2012

In this study, we investigated the virological characteristics, HBV DNA levels and presence of mutations of "a" determinant in the HBsAg S gene in chronic hepatitis B patients with coexisting HBsAg and anti-HBs. The 18 patients who were diagnosed with chronic hepatitis B were both positive for HBsAg and anti-HBs. HBV Among them, 15 patients were DNA positive. The median of HBV DNA levels in serum was $2.18{\times}10^7$ copies/mL with the HBsAg+/anti-HBsAb+ patients. Also, 4 of 8 HBeAg negative patients had HBV DNA levels higher than $10^4$ copies/mL and the median of HBV DNA levels was $2.03{\times}10^6$ copies/mL, which were significantly high. These results showed that viral replication still existed in most of the patients of the concomitant HBsAg and anti-HBs, and even in the some HBeAg negative patients. Furthermore, mutation within the "a" determinant of HBV were found in 7 of 15 patients. The most frequent changes were located at positions aa126. In addition, one mutation observed for HBsAg only positive.

• The Plant Pathology Journal
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• v.18 no.1
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• pp.18-22
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• 2002

Two peptaibol antibiotics, peptavirins A and B, which exhibited strong inhibitory effect against Tobacco mosaic vials (TMV) infection, were isolated from steam-cooked rice culture of Apiocrea sp.14T. The peptavirins were identified as new derivatives of chrysospermins, which are 19-mer and have been reported to be produced in a fungal isolate. The physicochemical properties of the peptavirins were mostly identical with chrysospermins A through D except for the UV absorption spectrum. The peptavirins inhibited the growths of the Grampositive bacteria tested, including the plant pathogenic bacterium, Corynebacterium lilium, and the fungus, Aspergillus niger. Peptavirin A was somewhat cytotoxic to cancer cell lines, especially K562 (leukemia) and UACC 62 (melanoma), whereas peptavirin B only exhibited slight cytotoxicity.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.1
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• pp.1-5
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• 2006

The effect of A/B moi ratios and sintering temperatures on dielectric properties and microstructure of $(Ba_{0.93}Ca_{0.07})_m(Ti_{0.82}Zr_{0.18})O_3$ ceramics were investigated. The dielectric constant decreased with increasing the A/B mol ratio. However, the dielectric loss is improved. As the dielectric properties of A/B mol ratio with m = 1.009 at sintered temperature $1260^{\circ}C$, we obtained dielectric constant 12,800, dielectric loss $3.5\%$ and Y5V temperature characteristics. Highly reliable Ni-MLCCs, 1.6mm$(length){\time}0.8mm(width){\time}0.8mm$(height) with capacitance of 1.23 ${\mu}F$ and 야ssipation loss of $5.2\%$ were obtained employing dielectric material composed of $(Ba_{0.93}Ca_{0.07})_{1.009}(Ti_{0.82}Zr_{0.18})O_3$ - $MnO_2\;0.2wt\%-Y_2O_3\;0.18wt\%,\;-\;SO_2\;0.15wt\%-(Ba_{0.4}Ca_{0.6})SiO_3\;1wt\%$.

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.237-242
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• 2015

Analysis of ancient DNA (aDNA) extracted from Ascaris is very important for understanding the phylogenetic lineage of the parasite species. When aDNAs obtained from a Joseon tomb (SN2-19-1) coprolite in which Ascaris eggs were identified were amplified with primers for cytochrome b (cyt b) and 18S small subunit ribosomal RNA (18S rRNA) gene, the outcome exhibited Ascaris specific amplicon bands. By cloning, sequencing, and analysis of the amplified DNA, we obtained information valuable for comprehending genetic lineage of Ascaris prevalent among pre-modern Joseon peoples.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.568-574
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• 2024

The development of radiation-tolerant radio-frequency (RF) systems can be a solution for applications in extreme radiation environments, such as nuclear power plant monitoring and space exploration. Among the crucial components within an RF system, the low noise amplifier (LNA) stands out due to its vulnerability to TID effects, mainly relying on transistors as its main devices. In this study, the TID effects in the LNA using standard 0.18 ㎛ complementary metal oxide semiconductors (CMOS) technology are estimated and analyzed. The results show that the LNA can withstand absorbed radiation up to 100 kGy. The S₂₁, S₁₁, noise figure (NF), stability (K), and linearity of the third input intercept point (IIP3) slightly shifted from the initial values of 0.8312 dB, 0.793 dB, 0.00381 dB, 1.34406, and 2.36066 dBm, respectively which are still comparable to the typical performances. Moreover, the standard 0.18 ㎛ technology has demonstrated its radiation tolerance, as it exhibits negligible performance degradation in the conventional LNA even when exposed to radiation levels up to 100 kGy. In this context, simulation approach offers a means to predict the TID effects and estimate the radiation exposure limit for electronic devices, particularly when transistors are used as the primary RF components.