• Journal of Microbiology and Biotechnology
• /
• v.28 no.2
• /
• pp.284-292
• /
• 2018

A novel ${\beta}$-agarase, AgaJ5, was identified from an agar-degrading marine bacterium, Gayadomonas joobiniege G7. It belongs to the glycoside hydrolase family 86 and is composed of 805 amino acids with a 30-amino-acid signal peptide. Zymogram analysis showed that purified AgaJ5 has agarase activity. The optimum temperature and pH for AgaJ5 activity were determined to be $30^{\circ}C$ and 4.5, respectively. AgaJ5 was an acidic ${\beta}$-agarase that had strong activity at a narrow pH range of 4.5-5.5, and was a cold-adapted enzyme, retaining 40% of enzymatic activity at $10^{\circ}C$. AgaJ5 required monovalent ions such as $Na^+$ and $K^+$ for its maximum activity, but its activity was severely inhibited by several metal ions. The $K_m$ and $V_{max}$ of AgaJ5 for agarose were 8.9 mg/ml and 188.6 U/mg, respectively. Notably, thin-layer chromatography, mass spectrometry, and agarose-liquefication analyses revealed that AgaJ5 was an endo-type ${\beta}$-agarase producing neoagarohexaose as the final main product of agarose hydrolysis. Therefore, these results suggest that AgaJ5 from G. joobiniege G7 is a novel endo-type neoagarohexaose-producing ${\beta}$-agarase having specific biochemical features that may be useful for industrial applications.

• Journal of the Korean Society of Safety
• /
• v.33 no.3
• /
• pp.15-20
• /
• 2018

There have been a number of major fatal fire accidents in Korea recently. The number of fires in 2017 were 44,178, which is not only increasing number of fires but also increasing in casualties. Particularly, the fire at Jecheon Sports Center, which suffered many casualties, is expected to have a huge impact. The cause of the fire has not been determined yet, but heat waves on the ceiling have also been pointed out. As such, the copper heating waves, which are used as a preventive measure against damage of pipes due to freezing of pipes, etc., always have a fire hazard. To determine the possibility of a flame-resistant heated fire, a positive electric cable product was used to artificially ignite and analyze the results. In case of a short circuit, the external covering of the positive electric cable is damaged, but not short circuit unless the heating material surrounding the wire is damaged. Due to the characteristics of heating cable for preventing copper waves, the chances of insulation becoming more severe due to moisture and temperature changes are higher than normal wires. If the internal heating system is carbonized by insulating deterioration without damage to the outer coating, it is likely to cause trekking, to form a winding loop in the heating materials, and to cause short circuit in the heated materials. For the positive temperature line, if the middle is shorted, the current continues to flow to the short circuit unless the breaker disconnects. Consequently, a heated fire that does not cut off the power immediately may leave multiple marks or cuts.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.11
• /
• pp.1577-1585
• /
• 2013

Bioethanol production from lignocellulose is considered as a sustainable biofuel supply. However, the low cellulose hydrolysis efficiency limits the cellulosic ethanol production. The cellulase is strongly inhibited by the major end product cellobiose, which can be relieved by the addition of ${\beta}$-glucosidase. In this study, three ${\beta}$-glucosidases from different organisms were respectively expressed in Saccharomyces cerevisiae and the ${\beta}$-glucosidase from Saccharomycopsis fibuligera showed the best activity (5.2 U/ml). The recombinant strain with S. fibuligera ${\beta}$-glucosidase could metabolize cellobiose with a specific growth rate similar to the control strain in glucose. This recombinant strain showed higher hydrolysis efficiency in the cellulose simultaneous saccharification and fermentation, when using the Trichoderma reesei cellulase, which is short of the ${\beta}$-glucosidase activity. The final ethanol concentration was 110% (using Avicel) and 89% (using acid-pretreated corncob) higher than the control strain. These results demonstrated the effect of ${\beta}$-glucosidase secretion in the recombinant S. cerevisiae for enhancing cellulosic ethanol conversion.

• The Korean Journal of Physiology and Pharmacology
• /
• v.18 no.6
• /
• pp.475-480
• /
• 2014

We investigated the question of whether cholesterol catabolite can influence expression of inflammatory cytokines via Toll-like receptors (TLR) in monocytic cells. Treatment of THP-1 monocytic cells with 27-hydroxycholesterol (27OHChol) resulted in induction of gene transcription of TLR6 and elevated level of cell surface TLR6. Addition of FSL-1, a TLR6 agonist, to 27OHChol-treated cells resulted in transcription of the $IL-1{\alpha}$ gene and enhanced secretion of the corresponding gene product. However, cholesterol did not affect TLR6 expression, and addition of FSL-1 to cholesterol-treated cells did not induce expression of $IL-1{\alpha}$. Using pharmacological inhibitors, we investigated molecular mechanisms underlying the expression of TLR6 and $IL-1{\alpha}$. Treatment with Akt inhibitor IV or U0126 resulted in significantly attenuated expression of TLR6 and $IL-1{\alpha}$ induced by 27OHChol and 27OHChol plus FSL-1, respectively. In addition, treatment with LY294002, SB202190, or SP600125 resulted in significantly attenuated secretion of $IL-1{\alpha}$. These results indicate that 27OHChol can induce inflammation by augmentation of TLR6-mediated production of $IL-1{\alpha}$ in monocytic cells via multiple signaling pathways.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.5
• /
• pp.1371-1379
• /
• 1997

Undetectable faults in a digital circuit are faults that no input patterms can detect.Identifying these faults in test geferation process is very time- consuming especially for sequential circuits .In this paper we present a new algorithm to identify unedtectable faults in sequential cirouits .In the alorithm. we identify uninitializable fip-flops and then, faults that prevent intialization of the fkip-flops(FPIs)are identified, finally propagation path of the FPI is checked. Time complexity of this algorithm is porportional to the product of the number of flip flops with at lest a self loop and the number of gates in the circuit. Experiments were performed on the ISCAS89 benchmark ciruits to show the feadibility of the proposed algorithm.We could identify large amount of undetectable faults(up to 50% of the number of flip-flops)in circuits with uninitializable flip-flops. Consider-ing that most of the time in test generation is cinsumed in identifying undetecatable faults, performance of test generator can be improved by using this algorithm as a pre-processing of test generation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.9C
• /
• pp.860-870
• /
• 2005

In this paper we propose a new method to derive GRM(Generalized Reed-Muller) coefacients for each $2^{n}$ polarities using cell of karnaugh map(k-map). Generally, there are the serial and parallel method to derive GRM coefficients. As a serial method, Green method generates GRM coefncients using transform matrix. And as a parallel method, Besslich algorithm produces GRM coefficients of each polarity using the generated anteriorly. Green's method generates GRM coefficients for n-variable by calculating transform matrix for one-variable and n-times kronecker product this matrix. And Besslich's method generates GRM coefficients of each polarity in order of Grey-code. But those methods have disadvantages that the number of variable exceeding four makes transform matrix large and there are so many operation steps. In this paper, GRM coefficients is generated by producing cell [$f_{i}$] minimizing variable on k-map and operating this cell [$f_{i}$] and transform matrix for one-variable. So, we can generate GRM coefficients of all polarities easily by using the proposed method.

• Journal of dental hygiene science
• /
• v.6 no.4
• /
• pp.251-254
• /
• 2006

In the current research for natural product with antimicrobial effects, various extracts of Mulberry Leaves against microorganisms were evaluated in terms of the minimum inhibitory concentrations(MIC). In general, Candida albicans was more antimicrobial activity than the other microorganisms such as Streptococcus mutans, Staphylococcus epidermis, and Staphylococcus aureus. The maximum activity was exhibited by ethanol extract of the leaves of Mulberry Leaves against Candida albicans (MIC, $1600{\mu}g/ml$). These results suggest that ethanol and water extracts of Mulberry Leaves have a potential antimicrobial activity.

• Journal of the Korean Geographical Society
• /
• v.42 no.5
• /
• pp.675-690
• /
• 2007

It has been widely believed that the ethnic relations in Honolulu and Hawai'i in the early twentieth century were little associated with racist ideology because the white race was minority in terms of the racial composition. In reality, however, the racial and ethnic issues have played a major role in forming the past and present relations among ethnic groups. This study shows that the white-supremacy ideology exerted a strong influence on minority groups in Honolulu throughout the immigration and settling-down process, as much as in the mainland U.S. Clear occupational stratification and residential segregation among the ethnic groups in Honolulu represented almost the same situation as in mainland cities. The social segregation and spatial propinquity of their residential neighborhoods facilitated the construction of dichotomized identity: "Local" versus "Haole". Such transformed identities were a product of on-going inter-ethnic negotiation process embedded in the non-white multi-ethnic neighborhoods.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.7
• /
• pp.459-466
• /
• 2014

In this paper, we suggest an efficient image processing method for fast paper currency counting with pattern recognition. The patterns are consisted of feature data in each note object extracted from full reflection image of notes and a general contact image sensor(CIS) is used to aggregate the feature images. The proposed pattern recognition algorithm can endure image variation when the paper currency is scanned because it is not sensitive to changes of image resulting in successful note recognition. We tested 100 notes per denomination and currency of several countries including Korea, U.S., China, EU, Britain and Turkey. To ensure the reliability of the result, we tested a total of 10 times per each direction of notes. We can conclude that this algorithm will be applicable to commercial product because of its successful recognition rates. The 100% recognition rates are obtained in almost cases with exceptional case of 99.9% in Euro and 99.8% in Turkish Lira.

• Journal of the Korea Convergence Society
• /
• v.11 no.1
• /
• pp.301-308
• /
• 2020

Based on the analysis of fire escape situations in public facility, this study was intended to propose a design of emergency light suitable for fire in public facility. A video analysis was conducted to understand the evacuation situation of public facility because the fire could not be randomized due to the disaster. Through video analysis, we were able to identify inconvenience and necessary needs in avoiding fire in public facility and reflected them in the design of emergency light, etc. As a result of the design of emergency light, the wall type induction lamp had different LED layout structures to minimize the thickness of the product. Ceiling induction lamps have been supplemented for additional installation in corridors of complex structures. The results of this study are designed based on the criteria used in the manufacture of actual emergency light and we intend to explore ways to be practical through further experiment measurements and complementary steps through expert advice.